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v4.6
 
   1/*
   2 * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
   3 *
   4 * Copyright (C) 2008-2012 ST-Ericsson AB
   5 * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
   6 *
   7 * Author: Linus Walleij <linus.walleij@stericsson.com>
   8 *
   9 * Initial version inspired by:
  10 *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
  11 * Initial adoption to PL022 by:
  12 *      Sachin Verma <sachin.verma@st.com>
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2 of the License, or
  17 * (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 */
  24
  25#include <linux/init.h>
  26#include <linux/module.h>
  27#include <linux/device.h>
  28#include <linux/ioport.h>
  29#include <linux/errno.h>
  30#include <linux/interrupt.h>
  31#include <linux/spi/spi.h>
  32#include <linux/delay.h>
  33#include <linux/clk.h>
  34#include <linux/err.h>
  35#include <linux/amba/bus.h>
  36#include <linux/amba/pl022.h>
  37#include <linux/io.h>
  38#include <linux/slab.h>
  39#include <linux/dmaengine.h>
  40#include <linux/dma-mapping.h>
  41#include <linux/scatterlist.h>
  42#include <linux/pm_runtime.h>
  43#include <linux/gpio.h>
  44#include <linux/of_gpio.h>
  45#include <linux/pinctrl/consumer.h>
  46
  47/*
  48 * This macro is used to define some register default values.
  49 * reg is masked with mask, the OR:ed with an (again masked)
  50 * val shifted sb steps to the left.
  51 */
  52#define SSP_WRITE_BITS(reg, val, mask, sb) \
  53 ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
  54
  55/*
  56 * This macro is also used to define some default values.
  57 * It will just shift val by sb steps to the left and mask
  58 * the result with mask.
  59 */
  60#define GEN_MASK_BITS(val, mask, sb) \
  61 (((val)<<(sb)) & (mask))
  62
  63#define DRIVE_TX		0
  64#define DO_NOT_DRIVE_TX		1
  65
  66#define DO_NOT_QUEUE_DMA	0
  67#define QUEUE_DMA		1
  68
  69#define RX_TRANSFER		1
  70#define TX_TRANSFER		2
  71
  72/*
  73 * Macros to access SSP Registers with their offsets
  74 */
  75#define SSP_CR0(r)	(r + 0x000)
  76#define SSP_CR1(r)	(r + 0x004)
  77#define SSP_DR(r)	(r + 0x008)
  78#define SSP_SR(r)	(r + 0x00C)
  79#define SSP_CPSR(r)	(r + 0x010)
  80#define SSP_IMSC(r)	(r + 0x014)
  81#define SSP_RIS(r)	(r + 0x018)
  82#define SSP_MIS(r)	(r + 0x01C)
  83#define SSP_ICR(r)	(r + 0x020)
  84#define SSP_DMACR(r)	(r + 0x024)
  85#define SSP_CSR(r)	(r + 0x030) /* vendor extension */
  86#define SSP_ITCR(r)	(r + 0x080)
  87#define SSP_ITIP(r)	(r + 0x084)
  88#define SSP_ITOP(r)	(r + 0x088)
  89#define SSP_TDR(r)	(r + 0x08C)
  90
  91#define SSP_PID0(r)	(r + 0xFE0)
  92#define SSP_PID1(r)	(r + 0xFE4)
  93#define SSP_PID2(r)	(r + 0xFE8)
  94#define SSP_PID3(r)	(r + 0xFEC)
  95
  96#define SSP_CID0(r)	(r + 0xFF0)
  97#define SSP_CID1(r)	(r + 0xFF4)
  98#define SSP_CID2(r)	(r + 0xFF8)
  99#define SSP_CID3(r)	(r + 0xFFC)
 100
 101/*
 102 * SSP Control Register 0  - SSP_CR0
 103 */
 104#define SSP_CR0_MASK_DSS	(0x0FUL << 0)
 105#define SSP_CR0_MASK_FRF	(0x3UL << 4)
 106#define SSP_CR0_MASK_SPO	(0x1UL << 6)
 107#define SSP_CR0_MASK_SPH	(0x1UL << 7)
 108#define SSP_CR0_MASK_SCR	(0xFFUL << 8)
 109
 110/*
 111 * The ST version of this block moves som bits
 112 * in SSP_CR0 and extends it to 32 bits
 113 */
 114#define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
 115#define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
 116#define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
 117#define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
 118
 119/*
 120 * SSP Control Register 0  - SSP_CR1
 121 */
 122#define SSP_CR1_MASK_LBM	(0x1UL << 0)
 123#define SSP_CR1_MASK_SSE	(0x1UL << 1)
 124#define SSP_CR1_MASK_MS		(0x1UL << 2)
 125#define SSP_CR1_MASK_SOD	(0x1UL << 3)
 126
 127/*
 128 * The ST version of this block adds some bits
 129 * in SSP_CR1
 130 */
 131#define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
 132#define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
 133#define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
 134#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
 135#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
 136/* This one is only in the PL023 variant */
 137#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
 138
 139/*
 140 * SSP Status Register - SSP_SR
 141 */
 142#define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
 143#define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
 144#define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
 145#define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
 146#define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
 147
 148/*
 149 * SSP Clock Prescale Register  - SSP_CPSR
 150 */
 151#define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
 152
 153/*
 154 * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
 155 */
 156#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
 157#define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
 158#define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
 159#define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
 160
 161/*
 162 * SSP Raw Interrupt Status Register - SSP_RIS
 163 */
 164/* Receive Overrun Raw Interrupt status */
 165#define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
 166/* Receive Timeout Raw Interrupt status */
 167#define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
 168/* Receive FIFO Raw Interrupt status */
 169#define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
 170/* Transmit FIFO Raw Interrupt status */
 171#define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
 172
 173/*
 174 * SSP Masked Interrupt Status Register - SSP_MIS
 175 */
 176/* Receive Overrun Masked Interrupt status */
 177#define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
 178/* Receive Timeout Masked Interrupt status */
 179#define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
 180/* Receive FIFO Masked Interrupt status */
 181#define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
 182/* Transmit FIFO Masked Interrupt status */
 183#define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
 184
 185/*
 186 * SSP Interrupt Clear Register - SSP_ICR
 187 */
 188/* Receive Overrun Raw Clear Interrupt bit */
 189#define SSP_ICR_MASK_RORIC		(0x1UL << 0)
 190/* Receive Timeout Clear Interrupt bit */
 191#define SSP_ICR_MASK_RTIC		(0x1UL << 1)
 192
 193/*
 194 * SSP DMA Control Register - SSP_DMACR
 195 */
 196/* Receive DMA Enable bit */
 197#define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
 198/* Transmit DMA Enable bit */
 199#define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
 200
 201/*
 202 * SSP Chip Select Control Register - SSP_CSR
 203 * (vendor extension)
 204 */
 205#define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
 206
 207/*
 208 * SSP Integration Test control Register - SSP_ITCR
 209 */
 210#define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
 211#define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
 212
 213/*
 214 * SSP Integration Test Input Register - SSP_ITIP
 215 */
 216#define ITIP_MASK_SSPRXD		 (0x1UL << 0)
 217#define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
 218#define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
 219#define ITIP_MASK_RXDMAC		 (0x1UL << 3)
 220#define ITIP_MASK_TXDMAC		 (0x1UL << 4)
 221#define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
 222
 223/*
 224 * SSP Integration Test output Register - SSP_ITOP
 225 */
 226#define ITOP_MASK_SSPTXD		 (0x1UL << 0)
 227#define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
 228#define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
 229#define ITOP_MASK_SSPOEn		 (0x1UL << 3)
 230#define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
 231#define ITOP_MASK_RORINTR		 (0x1UL << 5)
 232#define ITOP_MASK_RTINTR		 (0x1UL << 6)
 233#define ITOP_MASK_RXINTR		 (0x1UL << 7)
 234#define ITOP_MASK_TXINTR		 (0x1UL << 8)
 235#define ITOP_MASK_INTR			 (0x1UL << 9)
 236#define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
 237#define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
 238#define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
 239#define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
 240
 241/*
 242 * SSP Test Data Register - SSP_TDR
 243 */
 244#define TDR_MASK_TESTDATA		(0xFFFFFFFF)
 245
 246/*
 247 * Message State
 248 * we use the spi_message.state (void *) pointer to
 249 * hold a single state value, that's why all this
 250 * (void *) casting is done here.
 251 */
 252#define STATE_START			((void *) 0)
 253#define STATE_RUNNING			((void *) 1)
 254#define STATE_DONE			((void *) 2)
 255#define STATE_ERROR			((void *) -1)
 
 256
 257/*
 258 * SSP State - Whether Enabled or Disabled
 259 */
 260#define SSP_DISABLED			(0)
 261#define SSP_ENABLED			(1)
 262
 263/*
 264 * SSP DMA State - Whether DMA Enabled or Disabled
 265 */
 266#define SSP_DMA_DISABLED		(0)
 267#define SSP_DMA_ENABLED			(1)
 268
 269/*
 270 * SSP Clock Defaults
 271 */
 272#define SSP_DEFAULT_CLKRATE 0x2
 273#define SSP_DEFAULT_PRESCALE 0x40
 274
 275/*
 276 * SSP Clock Parameter ranges
 277 */
 278#define CPSDVR_MIN 0x02
 279#define CPSDVR_MAX 0xFE
 280#define SCR_MIN 0x00
 281#define SCR_MAX 0xFF
 282
 283/*
 284 * SSP Interrupt related Macros
 285 */
 286#define DEFAULT_SSP_REG_IMSC  0x0UL
 287#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
 288#define ENABLE_ALL_INTERRUPTS ( \
 289	SSP_IMSC_MASK_RORIM | \
 290	SSP_IMSC_MASK_RTIM | \
 291	SSP_IMSC_MASK_RXIM | \
 292	SSP_IMSC_MASK_TXIM \
 293)
 294
 295#define CLEAR_ALL_INTERRUPTS  0x3
 296
 297#define SPI_POLLING_TIMEOUT 1000
 298
 299/*
 300 * The type of reading going on on this chip
 301 */
 302enum ssp_reading {
 303	READING_NULL,
 304	READING_U8,
 305	READING_U16,
 306	READING_U32
 307};
 308
 309/**
 310 * The type of writing going on on this chip
 311 */
 312enum ssp_writing {
 313	WRITING_NULL,
 314	WRITING_U8,
 315	WRITING_U16,
 316	WRITING_U32
 317};
 318
 319/**
 320 * struct vendor_data - vendor-specific config parameters
 321 * for PL022 derivates
 322 * @fifodepth: depth of FIFOs (both)
 323 * @max_bpw: maximum number of bits per word
 324 * @unidir: supports unidirection transfers
 325 * @extended_cr: 32 bit wide control register 0 with extra
 326 * features and extra features in CR1 as found in the ST variants
 327 * @pl023: supports a subset of the ST extensions called "PL023"
 328 * @internal_cs_ctrl: supports chip select control register
 329 */
 330struct vendor_data {
 331	int fifodepth;
 332	int max_bpw;
 333	bool unidir;
 334	bool extended_cr;
 335	bool pl023;
 336	bool loopback;
 337	bool internal_cs_ctrl;
 338};
 339
 340/**
 341 * struct pl022 - This is the private SSP driver data structure
 342 * @adev: AMBA device model hookup
 343 * @vendor: vendor data for the IP block
 344 * @phybase: the physical memory where the SSP device resides
 345 * @virtbase: the virtual memory where the SSP is mapped
 346 * @clk: outgoing clock "SPICLK" for the SPI bus
 347 * @master: SPI framework hookup
 348 * @master_info: controller-specific data from machine setup
 349 * @pump_transfers: Tasklet used in Interrupt Transfer mode
 350 * @cur_msg: Pointer to current spi_message being processed
 351 * @cur_transfer: Pointer to current spi_transfer
 352 * @cur_chip: pointer to current clients chip(assigned from controller_state)
 353 * @next_msg_cs_active: the next message in the queue has been examined
 354 *  and it was found that it uses the same chip select as the previous
 355 *  message, so we left it active after the previous transfer, and it's
 356 *  active already.
 357 * @tx: current position in TX buffer to be read
 358 * @tx_end: end position in TX buffer to be read
 359 * @rx: current position in RX buffer to be written
 360 * @rx_end: end position in RX buffer to be written
 361 * @read: the type of read currently going on
 362 * @write: the type of write currently going on
 363 * @exp_fifo_level: expected FIFO level
 364 * @dma_rx_channel: optional channel for RX DMA
 365 * @dma_tx_channel: optional channel for TX DMA
 366 * @sgt_rx: scattertable for the RX transfer
 367 * @sgt_tx: scattertable for the TX transfer
 368 * @dummypage: a dummy page used for driving data on the bus with DMA
 369 * @cur_cs: current chip select (gpio)
 370 * @chipselects: list of chipselects (gpios)
 371 */
 372struct pl022 {
 373	struct amba_device		*adev;
 374	struct vendor_data		*vendor;
 375	resource_size_t			phybase;
 376	void __iomem			*virtbase;
 377	struct clk			*clk;
 378	struct spi_master		*master;
 379	struct pl022_ssp_controller	*master_info;
 380	/* Message per-transfer pump */
 381	struct tasklet_struct		pump_transfers;
 382	struct spi_message		*cur_msg;
 383	struct spi_transfer		*cur_transfer;
 384	struct chip_data		*cur_chip;
 385	bool				next_msg_cs_active;
 386	void				*tx;
 387	void				*tx_end;
 388	void				*rx;
 389	void				*rx_end;
 390	enum ssp_reading		read;
 391	enum ssp_writing		write;
 392	u32				exp_fifo_level;
 393	enum ssp_rx_level_trig		rx_lev_trig;
 394	enum ssp_tx_level_trig		tx_lev_trig;
 395	/* DMA settings */
 396#ifdef CONFIG_DMA_ENGINE
 397	struct dma_chan			*dma_rx_channel;
 398	struct dma_chan			*dma_tx_channel;
 399	struct sg_table			sgt_rx;
 400	struct sg_table			sgt_tx;
 401	char				*dummypage;
 402	bool				dma_running;
 403#endif
 404	int cur_cs;
 405	int *chipselects;
 406};
 407
 408/**
 409 * struct chip_data - To maintain runtime state of SSP for each client chip
 410 * @cr0: Value of control register CR0 of SSP - on later ST variants this
 411 *       register is 32 bits wide rather than just 16
 412 * @cr1: Value of control register CR1 of SSP
 413 * @dmacr: Value of DMA control Register of SSP
 414 * @cpsr: Value of Clock prescale register
 415 * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
 416 * @enable_dma: Whether to enable DMA or not
 417 * @read: function ptr to be used to read when doing xfer for this chip
 418 * @write: function ptr to be used to write when doing xfer for this chip
 419 * @cs_control: chip select callback provided by chip
 420 * @xfer_type: polling/interrupt/DMA
 421 *
 422 * Runtime state of the SSP controller, maintained per chip,
 423 * This would be set according to the current message that would be served
 424 */
 425struct chip_data {
 426	u32 cr0;
 427	u16 cr1;
 428	u16 dmacr;
 429	u16 cpsr;
 430	u8 n_bytes;
 431	bool enable_dma;
 432	enum ssp_reading read;
 433	enum ssp_writing write;
 434	void (*cs_control) (u32 command);
 435	int xfer_type;
 436};
 437
 438/**
 439 * null_cs_control - Dummy chip select function
 440 * @command: select/delect the chip
 441 *
 442 * If no chip select function is provided by client this is used as dummy
 443 * chip select
 444 */
 445static void null_cs_control(u32 command)
 446{
 447	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
 448}
 449
 450/**
 451 * internal_cs_control - Control chip select signals via SSP_CSR.
 452 * @pl022: SSP driver private data structure
 453 * @command: select/delect the chip
 454 *
 455 * Used on controller with internal chip select control via SSP_CSR register
 456 * (vendor extension). Each of the 5 LSB in the register controls one chip
 457 * select signal.
 458 */
 459static void internal_cs_control(struct pl022 *pl022, u32 command)
 460{
 461	u32 tmp;
 462
 463	tmp = readw(SSP_CSR(pl022->virtbase));
 464	if (command == SSP_CHIP_SELECT)
 465		tmp &= ~BIT(pl022->cur_cs);
 466	else
 467		tmp |= BIT(pl022->cur_cs);
 468	writew(tmp, SSP_CSR(pl022->virtbase));
 469}
 470
 471static void pl022_cs_control(struct pl022 *pl022, u32 command)
 472{
 473	if (pl022->vendor->internal_cs_ctrl)
 474		internal_cs_control(pl022, command);
 475	else if (gpio_is_valid(pl022->cur_cs))
 476		gpio_set_value(pl022->cur_cs, command);
 477	else
 478		pl022->cur_chip->cs_control(command);
 479}
 480
 481/**
 482 * giveback - current spi_message is over, schedule next message and call
 483 * callback of this message. Assumes that caller already
 484 * set message->status; dma and pio irqs are blocked
 485 * @pl022: SSP driver private data structure
 486 */
 487static void giveback(struct pl022 *pl022)
 488{
 489	struct spi_transfer *last_transfer;
 490	pl022->next_msg_cs_active = false;
 491
 492	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
 493					struct spi_transfer, transfer_list);
 494
 495	/* Delay if requested before any change in chip select */
 496	if (last_transfer->delay_usecs)
 497		/*
 498		 * FIXME: This runs in interrupt context.
 499		 * Is this really smart?
 500		 */
 501		udelay(last_transfer->delay_usecs);
 502
 503	if (!last_transfer->cs_change) {
 504		struct spi_message *next_msg;
 505
 506		/*
 507		 * cs_change was not set. We can keep the chip select
 508		 * enabled if there is message in the queue and it is
 509		 * for the same spi device.
 510		 *
 511		 * We cannot postpone this until pump_messages, because
 512		 * after calling msg->complete (below) the driver that
 513		 * sent the current message could be unloaded, which
 514		 * could invalidate the cs_control() callback...
 515		 */
 516		/* get a pointer to the next message, if any */
 517		next_msg = spi_get_next_queued_message(pl022->master);
 518
 519		/*
 520		 * see if the next and current messages point
 521		 * to the same spi device.
 522		 */
 523		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
 524			next_msg = NULL;
 525		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
 526			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
 527		else
 528			pl022->next_msg_cs_active = true;
 529
 530	}
 531
 532	pl022->cur_msg = NULL;
 533	pl022->cur_transfer = NULL;
 534	pl022->cur_chip = NULL;
 535
 536	/* disable the SPI/SSP operation */
 537	writew((readw(SSP_CR1(pl022->virtbase)) &
 538		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
 539
 540	spi_finalize_current_message(pl022->master);
 541}
 542
 543/**
 544 * flush - flush the FIFO to reach a clean state
 545 * @pl022: SSP driver private data structure
 546 */
 547static int flush(struct pl022 *pl022)
 548{
 549	unsigned long limit = loops_per_jiffy << 1;
 550
 551	dev_dbg(&pl022->adev->dev, "flush\n");
 552	do {
 553		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 554			readw(SSP_DR(pl022->virtbase));
 555	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
 556
 557	pl022->exp_fifo_level = 0;
 558
 559	return limit;
 560}
 561
 562/**
 563 * restore_state - Load configuration of current chip
 564 * @pl022: SSP driver private data structure
 565 */
 566static void restore_state(struct pl022 *pl022)
 567{
 568	struct chip_data *chip = pl022->cur_chip;
 569
 570	if (pl022->vendor->extended_cr)
 571		writel(chip->cr0, SSP_CR0(pl022->virtbase));
 572	else
 573		writew(chip->cr0, SSP_CR0(pl022->virtbase));
 574	writew(chip->cr1, SSP_CR1(pl022->virtbase));
 575	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
 576	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
 577	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
 578	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
 579}
 580
 581/*
 582 * Default SSP Register Values
 583 */
 584#define DEFAULT_SSP_REG_CR0 ( \
 585	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
 586	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
 587	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 588	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 589	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
 590)
 591
 592/* ST versions have slightly different bit layout */
 593#define DEFAULT_SSP_REG_CR0_ST ( \
 594	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
 595	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
 596	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 597	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 598	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
 599	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
 600	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
 601)
 602
 603/* The PL023 version is slightly different again */
 604#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
 605	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
 606	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 607	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 608	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
 609)
 610
 611#define DEFAULT_SSP_REG_CR1 ( \
 612	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
 613	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
 614	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
 615	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
 616)
 617
 618/* ST versions extend this register to use all 16 bits */
 619#define DEFAULT_SSP_REG_CR1_ST ( \
 620	DEFAULT_SSP_REG_CR1 | \
 621	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
 622	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
 623	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
 624	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
 625	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
 626)
 627
 628/*
 629 * The PL023 variant has further differences: no loopback mode, no microwire
 630 * support, and a new clock feedback delay setting.
 631 */
 632#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
 633	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
 634	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
 635	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
 636	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
 637	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
 638	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
 639	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
 640	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
 641)
 642
 643#define DEFAULT_SSP_REG_CPSR ( \
 644	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
 645)
 646
 647#define DEFAULT_SSP_REG_DMACR (\
 648	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
 649	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
 650)
 651
 652/**
 653 * load_ssp_default_config - Load default configuration for SSP
 654 * @pl022: SSP driver private data structure
 655 */
 656static void load_ssp_default_config(struct pl022 *pl022)
 657{
 658	if (pl022->vendor->pl023) {
 659		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
 660		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
 661	} else if (pl022->vendor->extended_cr) {
 662		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
 663		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
 664	} else {
 665		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
 666		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
 667	}
 668	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
 669	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
 670	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
 671	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
 672}
 673
 674/**
 675 * This will write to TX and read from RX according to the parameters
 676 * set in pl022.
 677 */
 678static void readwriter(struct pl022 *pl022)
 679{
 680
 681	/*
 682	 * The FIFO depth is different between primecell variants.
 683	 * I believe filling in too much in the FIFO might cause
 684	 * errons in 8bit wide transfers on ARM variants (just 8 words
 685	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
 686	 *
 687	 * To prevent this issue, the TX FIFO is only filled to the
 688	 * unused RX FIFO fill length, regardless of what the TX
 689	 * FIFO status flag indicates.
 690	 */
 691	dev_dbg(&pl022->adev->dev,
 692		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
 693		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
 694
 695	/* Read as much as you can */
 696	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 697	       && (pl022->rx < pl022->rx_end)) {
 698		switch (pl022->read) {
 699		case READING_NULL:
 700			readw(SSP_DR(pl022->virtbase));
 701			break;
 702		case READING_U8:
 703			*(u8 *) (pl022->rx) =
 704				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
 705			break;
 706		case READING_U16:
 707			*(u16 *) (pl022->rx) =
 708				(u16) readw(SSP_DR(pl022->virtbase));
 709			break;
 710		case READING_U32:
 711			*(u32 *) (pl022->rx) =
 712				readl(SSP_DR(pl022->virtbase));
 713			break;
 714		}
 715		pl022->rx += (pl022->cur_chip->n_bytes);
 716		pl022->exp_fifo_level--;
 717	}
 718	/*
 719	 * Write as much as possible up to the RX FIFO size
 720	 */
 721	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
 722	       && (pl022->tx < pl022->tx_end)) {
 723		switch (pl022->write) {
 724		case WRITING_NULL:
 725			writew(0x0, SSP_DR(pl022->virtbase));
 726			break;
 727		case WRITING_U8:
 728			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
 729			break;
 730		case WRITING_U16:
 731			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
 732			break;
 733		case WRITING_U32:
 734			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
 735			break;
 736		}
 737		pl022->tx += (pl022->cur_chip->n_bytes);
 738		pl022->exp_fifo_level++;
 739		/*
 740		 * This inner reader takes care of things appearing in the RX
 741		 * FIFO as we're transmitting. This will happen a lot since the
 742		 * clock starts running when you put things into the TX FIFO,
 743		 * and then things are continuously clocked into the RX FIFO.
 744		 */
 745		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 746		       && (pl022->rx < pl022->rx_end)) {
 747			switch (pl022->read) {
 748			case READING_NULL:
 749				readw(SSP_DR(pl022->virtbase));
 750				break;
 751			case READING_U8:
 752				*(u8 *) (pl022->rx) =
 753					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
 754				break;
 755			case READING_U16:
 756				*(u16 *) (pl022->rx) =
 757					(u16) readw(SSP_DR(pl022->virtbase));
 758				break;
 759			case READING_U32:
 760				*(u32 *) (pl022->rx) =
 761					readl(SSP_DR(pl022->virtbase));
 762				break;
 763			}
 764			pl022->rx += (pl022->cur_chip->n_bytes);
 765			pl022->exp_fifo_level--;
 766		}
 767	}
 768	/*
 769	 * When we exit here the TX FIFO should be full and the RX FIFO
 770	 * should be empty
 771	 */
 772}
 773
 774/**
 775 * next_transfer - Move to the Next transfer in the current spi message
 776 * @pl022: SSP driver private data structure
 777 *
 778 * This function moves though the linked list of spi transfers in the
 779 * current spi message and returns with the state of current spi
 780 * message i.e whether its last transfer is done(STATE_DONE) or
 781 * Next transfer is ready(STATE_RUNNING)
 782 */
 783static void *next_transfer(struct pl022 *pl022)
 784{
 785	struct spi_message *msg = pl022->cur_msg;
 786	struct spi_transfer *trans = pl022->cur_transfer;
 787
 788	/* Move to next transfer */
 789	if (trans->transfer_list.next != &msg->transfers) {
 790		pl022->cur_transfer =
 791		    list_entry(trans->transfer_list.next,
 792			       struct spi_transfer, transfer_list);
 793		return STATE_RUNNING;
 794	}
 795	return STATE_DONE;
 796}
 797
 798/*
 799 * This DMA functionality is only compiled in if we have
 800 * access to the generic DMA devices/DMA engine.
 801 */
 802#ifdef CONFIG_DMA_ENGINE
 803static void unmap_free_dma_scatter(struct pl022 *pl022)
 804{
 805	/* Unmap and free the SG tables */
 806	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
 807		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
 808	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
 809		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
 810	sg_free_table(&pl022->sgt_rx);
 811	sg_free_table(&pl022->sgt_tx);
 812}
 813
 814static void dma_callback(void *data)
 815{
 816	struct pl022 *pl022 = data;
 817	struct spi_message *msg = pl022->cur_msg;
 818
 819	BUG_ON(!pl022->sgt_rx.sgl);
 820
 821#ifdef VERBOSE_DEBUG
 822	/*
 823	 * Optionally dump out buffers to inspect contents, this is
 824	 * good if you want to convince yourself that the loopback
 825	 * read/write contents are the same, when adopting to a new
 826	 * DMA engine.
 827	 */
 828	{
 829		struct scatterlist *sg;
 830		unsigned int i;
 831
 832		dma_sync_sg_for_cpu(&pl022->adev->dev,
 833				    pl022->sgt_rx.sgl,
 834				    pl022->sgt_rx.nents,
 835				    DMA_FROM_DEVICE);
 836
 837		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
 838			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
 839			print_hex_dump(KERN_ERR, "SPI RX: ",
 840				       DUMP_PREFIX_OFFSET,
 841				       16,
 842				       1,
 843				       sg_virt(sg),
 844				       sg_dma_len(sg),
 845				       1);
 846		}
 847		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
 848			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
 849			print_hex_dump(KERN_ERR, "SPI TX: ",
 850				       DUMP_PREFIX_OFFSET,
 851				       16,
 852				       1,
 853				       sg_virt(sg),
 854				       sg_dma_len(sg),
 855				       1);
 856		}
 857	}
 858#endif
 859
 860	unmap_free_dma_scatter(pl022);
 861
 862	/* Update total bytes transferred */
 863	msg->actual_length += pl022->cur_transfer->len;
 864	if (pl022->cur_transfer->cs_change)
 865		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
 866
 867	/* Move to next transfer */
 868	msg->state = next_transfer(pl022);
 
 
 869	tasklet_schedule(&pl022->pump_transfers);
 870}
 871
 872static void setup_dma_scatter(struct pl022 *pl022,
 873			      void *buffer,
 874			      unsigned int length,
 875			      struct sg_table *sgtab)
 876{
 877	struct scatterlist *sg;
 878	int bytesleft = length;
 879	void *bufp = buffer;
 880	int mapbytes;
 881	int i;
 882
 883	if (buffer) {
 884		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
 885			/*
 886			 * If there are less bytes left than what fits
 887			 * in the current page (plus page alignment offset)
 888			 * we just feed in this, else we stuff in as much
 889			 * as we can.
 890			 */
 891			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
 892				mapbytes = bytesleft;
 893			else
 894				mapbytes = PAGE_SIZE - offset_in_page(bufp);
 895			sg_set_page(sg, virt_to_page(bufp),
 896				    mapbytes, offset_in_page(bufp));
 897			bufp += mapbytes;
 898			bytesleft -= mapbytes;
 899			dev_dbg(&pl022->adev->dev,
 900				"set RX/TX target page @ %p, %d bytes, %d left\n",
 901				bufp, mapbytes, bytesleft);
 902		}
 903	} else {
 904		/* Map the dummy buffer on every page */
 905		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
 906			if (bytesleft < PAGE_SIZE)
 907				mapbytes = bytesleft;
 908			else
 909				mapbytes = PAGE_SIZE;
 910			sg_set_page(sg, virt_to_page(pl022->dummypage),
 911				    mapbytes, 0);
 912			bytesleft -= mapbytes;
 913			dev_dbg(&pl022->adev->dev,
 914				"set RX/TX to dummy page %d bytes, %d left\n",
 915				mapbytes, bytesleft);
 916
 917		}
 918	}
 919	BUG_ON(bytesleft);
 920}
 921
 922/**
 923 * configure_dma - configures the channels for the next transfer
 924 * @pl022: SSP driver's private data structure
 925 */
 926static int configure_dma(struct pl022 *pl022)
 927{
 928	struct dma_slave_config rx_conf = {
 929		.src_addr = SSP_DR(pl022->phybase),
 930		.direction = DMA_DEV_TO_MEM,
 931		.device_fc = false,
 932	};
 933	struct dma_slave_config tx_conf = {
 934		.dst_addr = SSP_DR(pl022->phybase),
 935		.direction = DMA_MEM_TO_DEV,
 936		.device_fc = false,
 937	};
 938	unsigned int pages;
 939	int ret;
 940	int rx_sglen, tx_sglen;
 941	struct dma_chan *rxchan = pl022->dma_rx_channel;
 942	struct dma_chan *txchan = pl022->dma_tx_channel;
 943	struct dma_async_tx_descriptor *rxdesc;
 944	struct dma_async_tx_descriptor *txdesc;
 945
 946	/* Check that the channels are available */
 947	if (!rxchan || !txchan)
 948		return -ENODEV;
 949
 950	/*
 951	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
 952	 * Notice that the DMA engine uses one-to-one mapping. Since we can
 953	 * not trigger on 2 elements this needs explicit mapping rather than
 954	 * calculation.
 955	 */
 956	switch (pl022->rx_lev_trig) {
 957	case SSP_RX_1_OR_MORE_ELEM:
 958		rx_conf.src_maxburst = 1;
 959		break;
 960	case SSP_RX_4_OR_MORE_ELEM:
 961		rx_conf.src_maxburst = 4;
 962		break;
 963	case SSP_RX_8_OR_MORE_ELEM:
 964		rx_conf.src_maxburst = 8;
 965		break;
 966	case SSP_RX_16_OR_MORE_ELEM:
 967		rx_conf.src_maxburst = 16;
 968		break;
 969	case SSP_RX_32_OR_MORE_ELEM:
 970		rx_conf.src_maxburst = 32;
 971		break;
 972	default:
 973		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
 974		break;
 975	}
 976
 977	switch (pl022->tx_lev_trig) {
 978	case SSP_TX_1_OR_MORE_EMPTY_LOC:
 979		tx_conf.dst_maxburst = 1;
 980		break;
 981	case SSP_TX_4_OR_MORE_EMPTY_LOC:
 982		tx_conf.dst_maxburst = 4;
 983		break;
 984	case SSP_TX_8_OR_MORE_EMPTY_LOC:
 985		tx_conf.dst_maxburst = 8;
 986		break;
 987	case SSP_TX_16_OR_MORE_EMPTY_LOC:
 988		tx_conf.dst_maxburst = 16;
 989		break;
 990	case SSP_TX_32_OR_MORE_EMPTY_LOC:
 991		tx_conf.dst_maxburst = 32;
 992		break;
 993	default:
 994		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
 995		break;
 996	}
 997
 998	switch (pl022->read) {
 999	case READING_NULL:
1000		/* Use the same as for writing */
1001		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1002		break;
1003	case READING_U8:
1004		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1005		break;
1006	case READING_U16:
1007		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1008		break;
1009	case READING_U32:
1010		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1011		break;
1012	}
1013
1014	switch (pl022->write) {
1015	case WRITING_NULL:
1016		/* Use the same as for reading */
1017		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1018		break;
1019	case WRITING_U8:
1020		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1021		break;
1022	case WRITING_U16:
1023		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1024		break;
1025	case WRITING_U32:
1026		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1027		break;
1028	}
1029
1030	/* SPI pecularity: we need to read and write the same width */
1031	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1032		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1033	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1034		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1035	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1036
1037	dmaengine_slave_config(rxchan, &rx_conf);
1038	dmaengine_slave_config(txchan, &tx_conf);
1039
1040	/* Create sglists for the transfers */
1041	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1042	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1043
1044	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1045	if (ret)
1046		goto err_alloc_rx_sg;
1047
1048	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1049	if (ret)
1050		goto err_alloc_tx_sg;
1051
1052	/* Fill in the scatterlists for the RX+TX buffers */
1053	setup_dma_scatter(pl022, pl022->rx,
1054			  pl022->cur_transfer->len, &pl022->sgt_rx);
1055	setup_dma_scatter(pl022, pl022->tx,
1056			  pl022->cur_transfer->len, &pl022->sgt_tx);
1057
1058	/* Map DMA buffers */
1059	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1060			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1061	if (!rx_sglen)
1062		goto err_rx_sgmap;
1063
1064	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1065			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1066	if (!tx_sglen)
1067		goto err_tx_sgmap;
1068
1069	/* Send both scatterlists */
1070	rxdesc = dmaengine_prep_slave_sg(rxchan,
1071				      pl022->sgt_rx.sgl,
1072				      rx_sglen,
1073				      DMA_DEV_TO_MEM,
1074				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1075	if (!rxdesc)
1076		goto err_rxdesc;
1077
1078	txdesc = dmaengine_prep_slave_sg(txchan,
1079				      pl022->sgt_tx.sgl,
1080				      tx_sglen,
1081				      DMA_MEM_TO_DEV,
1082				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1083	if (!txdesc)
1084		goto err_txdesc;
1085
1086	/* Put the callback on the RX transfer only, that should finish last */
1087	rxdesc->callback = dma_callback;
1088	rxdesc->callback_param = pl022;
1089
1090	/* Submit and fire RX and TX with TX last so we're ready to read! */
1091	dmaengine_submit(rxdesc);
1092	dmaengine_submit(txdesc);
1093	dma_async_issue_pending(rxchan);
1094	dma_async_issue_pending(txchan);
1095	pl022->dma_running = true;
1096
1097	return 0;
1098
1099err_txdesc:
1100	dmaengine_terminate_all(txchan);
1101err_rxdesc:
1102	dmaengine_terminate_all(rxchan);
1103	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1104		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1105err_tx_sgmap:
1106	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1107		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1108err_rx_sgmap:
1109	sg_free_table(&pl022->sgt_tx);
1110err_alloc_tx_sg:
1111	sg_free_table(&pl022->sgt_rx);
1112err_alloc_rx_sg:
1113	return -ENOMEM;
1114}
1115
1116static int pl022_dma_probe(struct pl022 *pl022)
1117{
1118	dma_cap_mask_t mask;
1119
1120	/* Try to acquire a generic DMA engine slave channel */
1121	dma_cap_zero(mask);
1122	dma_cap_set(DMA_SLAVE, mask);
1123	/*
1124	 * We need both RX and TX channels to do DMA, else do none
1125	 * of them.
1126	 */
1127	pl022->dma_rx_channel = dma_request_channel(mask,
1128					    pl022->master_info->dma_filter,
1129					    pl022->master_info->dma_rx_param);
1130	if (!pl022->dma_rx_channel) {
1131		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1132		goto err_no_rxchan;
1133	}
1134
1135	pl022->dma_tx_channel = dma_request_channel(mask,
1136					    pl022->master_info->dma_filter,
1137					    pl022->master_info->dma_tx_param);
1138	if (!pl022->dma_tx_channel) {
1139		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1140		goto err_no_txchan;
1141	}
1142
1143	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1144	if (!pl022->dummypage)
1145		goto err_no_dummypage;
1146
1147	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1148		 dma_chan_name(pl022->dma_rx_channel),
1149		 dma_chan_name(pl022->dma_tx_channel));
1150
1151	return 0;
1152
1153err_no_dummypage:
1154	dma_release_channel(pl022->dma_tx_channel);
1155err_no_txchan:
1156	dma_release_channel(pl022->dma_rx_channel);
1157	pl022->dma_rx_channel = NULL;
1158err_no_rxchan:
1159	dev_err(&pl022->adev->dev,
1160			"Failed to work in dma mode, work without dma!\n");
1161	return -ENODEV;
1162}
1163
1164static int pl022_dma_autoprobe(struct pl022 *pl022)
1165{
1166	struct device *dev = &pl022->adev->dev;
1167	struct dma_chan *chan;
1168	int err;
1169
1170	/* automatically configure DMA channels from platform, normally using DT */
1171	chan = dma_request_slave_channel_reason(dev, "rx");
1172	if (IS_ERR(chan)) {
1173		err = PTR_ERR(chan);
1174		goto err_no_rxchan;
1175	}
1176
1177	pl022->dma_rx_channel = chan;
1178
1179	chan = dma_request_slave_channel_reason(dev, "tx");
1180	if (IS_ERR(chan)) {
1181		err = PTR_ERR(chan);
1182		goto err_no_txchan;
1183	}
1184
1185	pl022->dma_tx_channel = chan;
1186
1187	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1188	if (!pl022->dummypage) {
1189		err = -ENOMEM;
1190		goto err_no_dummypage;
1191	}
1192
1193	return 0;
1194
1195err_no_dummypage:
1196	dma_release_channel(pl022->dma_tx_channel);
1197	pl022->dma_tx_channel = NULL;
1198err_no_txchan:
1199	dma_release_channel(pl022->dma_rx_channel);
1200	pl022->dma_rx_channel = NULL;
1201err_no_rxchan:
1202	return err;
1203}
1204		
1205static void terminate_dma(struct pl022 *pl022)
1206{
1207	struct dma_chan *rxchan = pl022->dma_rx_channel;
1208	struct dma_chan *txchan = pl022->dma_tx_channel;
1209
1210	dmaengine_terminate_all(rxchan);
1211	dmaengine_terminate_all(txchan);
1212	unmap_free_dma_scatter(pl022);
1213	pl022->dma_running = false;
1214}
1215
1216static void pl022_dma_remove(struct pl022 *pl022)
1217{
1218	if (pl022->dma_running)
1219		terminate_dma(pl022);
1220	if (pl022->dma_tx_channel)
1221		dma_release_channel(pl022->dma_tx_channel);
1222	if (pl022->dma_rx_channel)
1223		dma_release_channel(pl022->dma_rx_channel);
1224	kfree(pl022->dummypage);
1225}
1226
1227#else
1228static inline int configure_dma(struct pl022 *pl022)
1229{
1230	return -ENODEV;
1231}
1232
1233static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1234{
1235	return 0;
1236}
1237
1238static inline int pl022_dma_probe(struct pl022 *pl022)
1239{
1240	return 0;
1241}
1242
1243static inline void pl022_dma_remove(struct pl022 *pl022)
1244{
1245}
1246#endif
1247
1248/**
1249 * pl022_interrupt_handler - Interrupt handler for SSP controller
1250 *
1251 * This function handles interrupts generated for an interrupt based transfer.
1252 * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1253 * current message's state as STATE_ERROR and schedule the tasklet
1254 * pump_transfers which will do the postprocessing of the current message by
1255 * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1256 * more data, and writes data in TX FIFO till it is not full. If we complete
1257 * the transfer we move to the next transfer and schedule the tasklet.
1258 */
1259static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1260{
1261	struct pl022 *pl022 = dev_id;
1262	struct spi_message *msg = pl022->cur_msg;
1263	u16 irq_status = 0;
1264
1265	if (unlikely(!msg)) {
1266		dev_err(&pl022->adev->dev,
1267			"bad message state in interrupt handler");
1268		/* Never fail */
1269		return IRQ_HANDLED;
1270	}
1271
1272	/* Read the Interrupt Status Register */
1273	irq_status = readw(SSP_MIS(pl022->virtbase));
1274
1275	if (unlikely(!irq_status))
1276		return IRQ_NONE;
1277
1278	/*
1279	 * This handles the FIFO interrupts, the timeout
1280	 * interrupts are flatly ignored, they cannot be
1281	 * trusted.
1282	 */
1283	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1284		/*
1285		 * Overrun interrupt - bail out since our Data has been
1286		 * corrupted
1287		 */
1288		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1289		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1290			dev_err(&pl022->adev->dev,
1291				"RXFIFO is full\n");
1292
1293		/*
1294		 * Disable and clear interrupts, disable SSP,
1295		 * mark message with bad status so it can be
1296		 * retried.
1297		 */
1298		writew(DISABLE_ALL_INTERRUPTS,
1299		       SSP_IMSC(pl022->virtbase));
1300		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1301		writew((readw(SSP_CR1(pl022->virtbase)) &
1302			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1303		msg->state = STATE_ERROR;
1304
1305		/* Schedule message queue handler */
1306		tasklet_schedule(&pl022->pump_transfers);
1307		return IRQ_HANDLED;
1308	}
1309
1310	readwriter(pl022);
1311
1312	if (pl022->tx == pl022->tx_end) {
1313		/* Disable Transmit interrupt, enable receive interrupt */
1314		writew((readw(SSP_IMSC(pl022->virtbase)) &
1315		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1316		       SSP_IMSC(pl022->virtbase));
1317	}
1318
1319	/*
1320	 * Since all transactions must write as much as shall be read,
1321	 * we can conclude the entire transaction once RX is complete.
1322	 * At this point, all TX will always be finished.
1323	 */
1324	if (pl022->rx >= pl022->rx_end) {
1325		writew(DISABLE_ALL_INTERRUPTS,
1326		       SSP_IMSC(pl022->virtbase));
1327		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1328		if (unlikely(pl022->rx > pl022->rx_end)) {
1329			dev_warn(&pl022->adev->dev, "read %u surplus "
1330				 "bytes (did you request an odd "
1331				 "number of bytes on a 16bit bus?)\n",
1332				 (u32) (pl022->rx - pl022->rx_end));
1333		}
1334		/* Update total bytes transferred */
1335		msg->actual_length += pl022->cur_transfer->len;
1336		if (pl022->cur_transfer->cs_change)
1337			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1338		/* Move to next transfer */
1339		msg->state = next_transfer(pl022);
 
 
1340		tasklet_schedule(&pl022->pump_transfers);
1341		return IRQ_HANDLED;
1342	}
1343
1344	return IRQ_HANDLED;
1345}
1346
1347/**
1348 * This sets up the pointers to memory for the next message to
1349 * send out on the SPI bus.
1350 */
1351static int set_up_next_transfer(struct pl022 *pl022,
1352				struct spi_transfer *transfer)
1353{
1354	int residue;
1355
1356	/* Sanity check the message for this bus width */
1357	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1358	if (unlikely(residue != 0)) {
1359		dev_err(&pl022->adev->dev,
1360			"message of %u bytes to transmit but the current "
1361			"chip bus has a data width of %u bytes!\n",
1362			pl022->cur_transfer->len,
1363			pl022->cur_chip->n_bytes);
1364		dev_err(&pl022->adev->dev, "skipping this message\n");
1365		return -EIO;
1366	}
1367	pl022->tx = (void *)transfer->tx_buf;
1368	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1369	pl022->rx = (void *)transfer->rx_buf;
1370	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1371	pl022->write =
1372	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1373	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1374	return 0;
1375}
1376
1377/**
1378 * pump_transfers - Tasklet function which schedules next transfer
1379 * when running in interrupt or DMA transfer mode.
1380 * @data: SSP driver private data structure
1381 *
1382 */
1383static void pump_transfers(unsigned long data)
1384{
1385	struct pl022 *pl022 = (struct pl022 *) data;
1386	struct spi_message *message = NULL;
1387	struct spi_transfer *transfer = NULL;
1388	struct spi_transfer *previous = NULL;
1389
1390	/* Get current state information */
1391	message = pl022->cur_msg;
1392	transfer = pl022->cur_transfer;
1393
1394	/* Handle for abort */
1395	if (message->state == STATE_ERROR) {
1396		message->status = -EIO;
1397		giveback(pl022);
1398		return;
1399	}
1400
1401	/* Handle end of message */
1402	if (message->state == STATE_DONE) {
1403		message->status = 0;
1404		giveback(pl022);
1405		return;
1406	}
1407
1408	/* Delay if requested at end of transfer before CS change */
1409	if (message->state == STATE_RUNNING) {
1410		previous = list_entry(transfer->transfer_list.prev,
1411					struct spi_transfer,
1412					transfer_list);
1413		if (previous->delay_usecs)
1414			/*
1415			 * FIXME: This runs in interrupt context.
1416			 * Is this really smart?
1417			 */
1418			udelay(previous->delay_usecs);
1419
1420		/* Reselect chip select only if cs_change was requested */
1421		if (previous->cs_change)
1422			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1423	} else {
1424		/* STATE_START */
1425		message->state = STATE_RUNNING;
1426	}
1427
1428	if (set_up_next_transfer(pl022, transfer)) {
1429		message->state = STATE_ERROR;
1430		message->status = -EIO;
1431		giveback(pl022);
1432		return;
1433	}
1434	/* Flush the FIFOs and let's go! */
1435	flush(pl022);
1436
1437	if (pl022->cur_chip->enable_dma) {
1438		if (configure_dma(pl022)) {
1439			dev_dbg(&pl022->adev->dev,
1440				"configuration of DMA failed, fall back to interrupt mode\n");
1441			goto err_config_dma;
1442		}
1443		return;
1444	}
1445
1446err_config_dma:
1447	/* enable all interrupts except RX */
1448	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1449}
1450
1451static void do_interrupt_dma_transfer(struct pl022 *pl022)
1452{
1453	/*
1454	 * Default is to enable all interrupts except RX -
1455	 * this will be enabled once TX is complete
1456	 */
1457	u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
1458
1459	/* Enable target chip, if not already active */
1460	if (!pl022->next_msg_cs_active)
1461		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1462
1463	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1464		/* Error path */
1465		pl022->cur_msg->state = STATE_ERROR;
1466		pl022->cur_msg->status = -EIO;
1467		giveback(pl022);
1468		return;
1469	}
1470	/* If we're using DMA, set up DMA here */
1471	if (pl022->cur_chip->enable_dma) {
1472		/* Configure DMA transfer */
1473		if (configure_dma(pl022)) {
1474			dev_dbg(&pl022->adev->dev,
1475				"configuration of DMA failed, fall back to interrupt mode\n");
1476			goto err_config_dma;
1477		}
1478		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1479		irqflags = DISABLE_ALL_INTERRUPTS;
1480	}
1481err_config_dma:
1482	/* Enable SSP, turn on interrupts */
1483	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1484	       SSP_CR1(pl022->virtbase));
1485	writew(irqflags, SSP_IMSC(pl022->virtbase));
1486}
1487
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1488static void do_polling_transfer(struct pl022 *pl022)
1489{
1490	struct spi_message *message = NULL;
1491	struct spi_transfer *transfer = NULL;
1492	struct spi_transfer *previous = NULL;
1493	struct chip_data *chip;
1494	unsigned long time, timeout;
1495
1496	chip = pl022->cur_chip;
1497	message = pl022->cur_msg;
1498
1499	while (message->state != STATE_DONE) {
1500		/* Handle for abort */
1501		if (message->state == STATE_ERROR)
1502			break;
1503		transfer = pl022->cur_transfer;
1504
1505		/* Delay if requested at end of transfer */
1506		if (message->state == STATE_RUNNING) {
1507			previous =
1508			    list_entry(transfer->transfer_list.prev,
1509				       struct spi_transfer, transfer_list);
1510			if (previous->delay_usecs)
1511				udelay(previous->delay_usecs);
1512			if (previous->cs_change)
1513				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1514		} else {
1515			/* STATE_START */
1516			message->state = STATE_RUNNING;
1517			if (!pl022->next_msg_cs_active)
1518				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1519		}
1520
1521		/* Configuration Changing Per Transfer */
1522		if (set_up_next_transfer(pl022, transfer)) {
1523			/* Error path */
1524			message->state = STATE_ERROR;
1525			break;
1526		}
1527		/* Flush FIFOs and enable SSP */
1528		flush(pl022);
1529		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1530		       SSP_CR1(pl022->virtbase));
1531
1532		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1533
1534		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1535		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1536			time = jiffies;
1537			readwriter(pl022);
1538			if (time_after(time, timeout)) {
1539				dev_warn(&pl022->adev->dev,
1540				"%s: timeout!\n", __func__);
1541				message->state = STATE_ERROR;
 
1542				goto out;
1543			}
1544			cpu_relax();
1545		}
1546
1547		/* Update total byte transferred */
1548		message->actual_length += pl022->cur_transfer->len;
1549		if (pl022->cur_transfer->cs_change)
1550			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1551		/* Move to next transfer */
1552		message->state = next_transfer(pl022);
 
 
 
1553	}
1554out:
1555	/* Handle end of message */
1556	if (message->state == STATE_DONE)
1557		message->status = 0;
 
 
1558	else
1559		message->status = -EIO;
1560
1561	giveback(pl022);
1562	return;
1563}
1564
1565static int pl022_transfer_one_message(struct spi_master *master,
1566				      struct spi_message *msg)
1567{
1568	struct pl022 *pl022 = spi_master_get_devdata(master);
1569
1570	/* Initial message state */
1571	pl022->cur_msg = msg;
1572	msg->state = STATE_START;
1573
1574	pl022->cur_transfer = list_entry(msg->transfers.next,
1575					 struct spi_transfer, transfer_list);
1576
1577	/* Setup the SPI using the per chip configuration */
1578	pl022->cur_chip = spi_get_ctldata(msg->spi);
1579	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1580
1581	restore_state(pl022);
1582	flush(pl022);
1583
1584	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1585		do_polling_transfer(pl022);
1586	else
1587		do_interrupt_dma_transfer(pl022);
1588
1589	return 0;
1590}
1591
1592static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1593{
1594	struct pl022 *pl022 = spi_master_get_devdata(master);
1595
1596	/* nothing more to do - disable spi/ssp and power off */
1597	writew((readw(SSP_CR1(pl022->virtbase)) &
1598		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1599
1600	return 0;
1601}
1602
1603static int verify_controller_parameters(struct pl022 *pl022,
1604				struct pl022_config_chip const *chip_info)
1605{
1606	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1607	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1608		dev_err(&pl022->adev->dev,
1609			"interface is configured incorrectly\n");
1610		return -EINVAL;
1611	}
1612	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1613	    (!pl022->vendor->unidir)) {
1614		dev_err(&pl022->adev->dev,
1615			"unidirectional mode not supported in this "
1616			"hardware version\n");
1617		return -EINVAL;
1618	}
1619	if ((chip_info->hierarchy != SSP_MASTER)
1620	    && (chip_info->hierarchy != SSP_SLAVE)) {
1621		dev_err(&pl022->adev->dev,
1622			"hierarchy is configured incorrectly\n");
1623		return -EINVAL;
1624	}
1625	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1626	    && (chip_info->com_mode != DMA_TRANSFER)
1627	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1628		dev_err(&pl022->adev->dev,
1629			"Communication mode is configured incorrectly\n");
1630		return -EINVAL;
1631	}
1632	switch (chip_info->rx_lev_trig) {
1633	case SSP_RX_1_OR_MORE_ELEM:
1634	case SSP_RX_4_OR_MORE_ELEM:
1635	case SSP_RX_8_OR_MORE_ELEM:
1636		/* These are always OK, all variants can handle this */
1637		break;
1638	case SSP_RX_16_OR_MORE_ELEM:
1639		if (pl022->vendor->fifodepth < 16) {
1640			dev_err(&pl022->adev->dev,
1641			"RX FIFO Trigger Level is configured incorrectly\n");
1642			return -EINVAL;
1643		}
1644		break;
1645	case SSP_RX_32_OR_MORE_ELEM:
1646		if (pl022->vendor->fifodepth < 32) {
1647			dev_err(&pl022->adev->dev,
1648			"RX FIFO Trigger Level is configured incorrectly\n");
1649			return -EINVAL;
1650		}
1651		break;
1652	default:
1653		dev_err(&pl022->adev->dev,
1654			"RX FIFO Trigger Level is configured incorrectly\n");
1655		return -EINVAL;
1656	}
1657	switch (chip_info->tx_lev_trig) {
1658	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1659	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1660	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1661		/* These are always OK, all variants can handle this */
1662		break;
1663	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1664		if (pl022->vendor->fifodepth < 16) {
1665			dev_err(&pl022->adev->dev,
1666			"TX FIFO Trigger Level is configured incorrectly\n");
1667			return -EINVAL;
1668		}
1669		break;
1670	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1671		if (pl022->vendor->fifodepth < 32) {
1672			dev_err(&pl022->adev->dev,
1673			"TX FIFO Trigger Level is configured incorrectly\n");
1674			return -EINVAL;
1675		}
1676		break;
1677	default:
1678		dev_err(&pl022->adev->dev,
1679			"TX FIFO Trigger Level is configured incorrectly\n");
1680		return -EINVAL;
1681	}
1682	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1683		if ((chip_info->ctrl_len < SSP_BITS_4)
1684		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1685			dev_err(&pl022->adev->dev,
1686				"CTRL LEN is configured incorrectly\n");
1687			return -EINVAL;
1688		}
1689		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1690		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1691			dev_err(&pl022->adev->dev,
1692				"Wait State is configured incorrectly\n");
1693			return -EINVAL;
1694		}
1695		/* Half duplex is only available in the ST Micro version */
1696		if (pl022->vendor->extended_cr) {
1697			if ((chip_info->duplex !=
1698			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1699			    && (chip_info->duplex !=
1700				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1701				dev_err(&pl022->adev->dev,
1702					"Microwire duplex mode is configured incorrectly\n");
1703				return -EINVAL;
1704			}
1705		} else {
1706			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1707				dev_err(&pl022->adev->dev,
1708					"Microwire half duplex mode requested,"
1709					" but this is only available in the"
1710					" ST version of PL022\n");
1711			return -EINVAL;
1712		}
1713	}
1714	return 0;
1715}
1716
1717static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1718{
1719	return rate / (cpsdvsr * (1 + scr));
1720}
1721
1722static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1723				    ssp_clock_params * clk_freq)
1724{
1725	/* Lets calculate the frequency parameters */
1726	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1727	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1728		best_scr = 0, tmp, found = 0;
1729
1730	rate = clk_get_rate(pl022->clk);
1731	/* cpsdvscr = 2 & scr 0 */
1732	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1733	/* cpsdvsr = 254 & scr = 255 */
1734	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1735
1736	if (freq > max_tclk)
1737		dev_warn(&pl022->adev->dev,
1738			"Max speed that can be programmed is %d Hz, you requested %d\n",
1739			max_tclk, freq);
1740
1741	if (freq < min_tclk) {
1742		dev_err(&pl022->adev->dev,
1743			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1744			freq, min_tclk);
1745		return -EINVAL;
1746	}
1747
1748	/*
1749	 * best_freq will give closest possible available rate (<= requested
1750	 * freq) for all values of scr & cpsdvsr.
1751	 */
1752	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1753		while (scr <= SCR_MAX) {
1754			tmp = spi_rate(rate, cpsdvsr, scr);
1755
1756			if (tmp > freq) {
1757				/* we need lower freq */
1758				scr++;
1759				continue;
1760			}
1761
1762			/*
1763			 * If found exact value, mark found and break.
1764			 * If found more closer value, update and break.
1765			 */
1766			if (tmp > best_freq) {
1767				best_freq = tmp;
1768				best_cpsdvsr = cpsdvsr;
1769				best_scr = scr;
1770
1771				if (tmp == freq)
1772					found = 1;
1773			}
1774			/*
1775			 * increased scr will give lower rates, which are not
1776			 * required
1777			 */
1778			break;
1779		}
1780		cpsdvsr += 2;
1781		scr = SCR_MIN;
1782	}
1783
1784	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1785			freq);
1786
1787	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1788	clk_freq->scr = (u8) (best_scr & 0xFF);
1789	dev_dbg(&pl022->adev->dev,
1790		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1791		freq, best_freq);
1792	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1793		clk_freq->cpsdvsr, clk_freq->scr);
1794
1795	return 0;
1796}
1797
1798/*
1799 * A piece of default chip info unless the platform
1800 * supplies it.
1801 */
1802static const struct pl022_config_chip pl022_default_chip_info = {
1803	.com_mode = POLLING_TRANSFER,
1804	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1805	.hierarchy = SSP_SLAVE,
1806	.slave_tx_disable = DO_NOT_DRIVE_TX,
1807	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1808	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1809	.ctrl_len = SSP_BITS_8,
1810	.wait_state = SSP_MWIRE_WAIT_ZERO,
1811	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1812	.cs_control = null_cs_control,
1813};
1814
1815/**
1816 * pl022_setup - setup function registered to SPI master framework
1817 * @spi: spi device which is requesting setup
1818 *
1819 * This function is registered to the SPI framework for this SPI master
1820 * controller. If it is the first time when setup is called by this device,
1821 * this function will initialize the runtime state for this chip and save
1822 * the same in the device structure. Else it will update the runtime info
1823 * with the updated chip info. Nothing is really being written to the
1824 * controller hardware here, that is not done until the actual transfer
1825 * commence.
1826 */
1827static int pl022_setup(struct spi_device *spi)
1828{
1829	struct pl022_config_chip const *chip_info;
1830	struct pl022_config_chip chip_info_dt;
1831	struct chip_data *chip;
1832	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1833	int status = 0;
1834	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1835	unsigned int bits = spi->bits_per_word;
1836	u32 tmp;
1837	struct device_node *np = spi->dev.of_node;
1838
1839	if (!spi->max_speed_hz)
1840		return -EINVAL;
1841
1842	/* Get controller_state if one is supplied */
1843	chip = spi_get_ctldata(spi);
1844
1845	if (chip == NULL) {
1846		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1847		if (!chip)
1848			return -ENOMEM;
1849		dev_dbg(&spi->dev,
1850			"allocated memory for controller's runtime state\n");
1851	}
1852
1853	/* Get controller data if one is supplied */
1854	chip_info = spi->controller_data;
1855
1856	if (chip_info == NULL) {
1857		if (np) {
1858			chip_info_dt = pl022_default_chip_info;
1859
1860			chip_info_dt.hierarchy = SSP_MASTER;
1861			of_property_read_u32(np, "pl022,interface",
1862				&chip_info_dt.iface);
1863			of_property_read_u32(np, "pl022,com-mode",
1864				&chip_info_dt.com_mode);
1865			of_property_read_u32(np, "pl022,rx-level-trig",
1866				&chip_info_dt.rx_lev_trig);
1867			of_property_read_u32(np, "pl022,tx-level-trig",
1868				&chip_info_dt.tx_lev_trig);
1869			of_property_read_u32(np, "pl022,ctrl-len",
1870				&chip_info_dt.ctrl_len);
1871			of_property_read_u32(np, "pl022,wait-state",
1872				&chip_info_dt.wait_state);
1873			of_property_read_u32(np, "pl022,duplex",
1874				&chip_info_dt.duplex);
1875
1876			chip_info = &chip_info_dt;
1877		} else {
1878			chip_info = &pl022_default_chip_info;
1879			/* spi_board_info.controller_data not is supplied */
1880			dev_dbg(&spi->dev,
1881				"using default controller_data settings\n");
1882		}
1883	} else
1884		dev_dbg(&spi->dev,
1885			"using user supplied controller_data settings\n");
1886
1887	/*
1888	 * We can override with custom divisors, else we use the board
1889	 * frequency setting
1890	 */
1891	if ((0 == chip_info->clk_freq.cpsdvsr)
1892	    && (0 == chip_info->clk_freq.scr)) {
1893		status = calculate_effective_freq(pl022,
1894						  spi->max_speed_hz,
1895						  &clk_freq);
1896		if (status < 0)
1897			goto err_config_params;
1898	} else {
1899		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1900		if ((clk_freq.cpsdvsr % 2) != 0)
1901			clk_freq.cpsdvsr =
1902				clk_freq.cpsdvsr - 1;
1903	}
1904	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1905	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1906		status = -EINVAL;
1907		dev_err(&spi->dev,
1908			"cpsdvsr is configured incorrectly\n");
1909		goto err_config_params;
1910	}
1911
1912	status = verify_controller_parameters(pl022, chip_info);
1913	if (status) {
1914		dev_err(&spi->dev, "controller data is incorrect");
1915		goto err_config_params;
1916	}
1917
1918	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1919	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1920
1921	/* Now set controller state based on controller data */
1922	chip->xfer_type = chip_info->com_mode;
1923	if (!chip_info->cs_control) {
1924		chip->cs_control = null_cs_control;
1925		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1926			dev_warn(&spi->dev,
1927				 "invalid chip select\n");
1928	} else
1929		chip->cs_control = chip_info->cs_control;
1930
1931	/* Check bits per word with vendor specific range */
1932	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1933		status = -ENOTSUPP;
1934		dev_err(&spi->dev, "illegal data size for this controller!\n");
1935		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1936				pl022->vendor->max_bpw);
1937		goto err_config_params;
1938	} else if (bits <= 8) {
1939		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1940		chip->n_bytes = 1;
1941		chip->read = READING_U8;
1942		chip->write = WRITING_U8;
1943	} else if (bits <= 16) {
1944		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1945		chip->n_bytes = 2;
1946		chip->read = READING_U16;
1947		chip->write = WRITING_U16;
1948	} else {
1949		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1950		chip->n_bytes = 4;
1951		chip->read = READING_U32;
1952		chip->write = WRITING_U32;
1953	}
1954
1955	/* Now Initialize all register settings required for this chip */
1956	chip->cr0 = 0;
1957	chip->cr1 = 0;
1958	chip->dmacr = 0;
1959	chip->cpsr = 0;
1960	if ((chip_info->com_mode == DMA_TRANSFER)
1961	    && ((pl022->master_info)->enable_dma)) {
1962		chip->enable_dma = true;
1963		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1964		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1965			       SSP_DMACR_MASK_RXDMAE, 0);
1966		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1967			       SSP_DMACR_MASK_TXDMAE, 1);
1968	} else {
1969		chip->enable_dma = false;
1970		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1971		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1972			       SSP_DMACR_MASK_RXDMAE, 0);
1973		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1974			       SSP_DMACR_MASK_TXDMAE, 1);
1975	}
1976
1977	chip->cpsr = clk_freq.cpsdvsr;
1978
1979	/* Special setup for the ST micro extended control registers */
1980	if (pl022->vendor->extended_cr) {
1981		u32 etx;
1982
1983		if (pl022->vendor->pl023) {
1984			/* These bits are only in the PL023 */
1985			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
1986				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
1987		} else {
1988			/* These bits are in the PL022 but not PL023 */
1989			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
1990				       SSP_CR0_MASK_HALFDUP_ST, 5);
1991			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
1992				       SSP_CR0_MASK_CSS_ST, 16);
1993			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
1994				       SSP_CR0_MASK_FRF_ST, 21);
1995			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
1996				       SSP_CR1_MASK_MWAIT_ST, 6);
1997		}
1998		SSP_WRITE_BITS(chip->cr0, bits - 1,
1999			       SSP_CR0_MASK_DSS_ST, 0);
2000
2001		if (spi->mode & SPI_LSB_FIRST) {
2002			tmp = SSP_RX_LSB;
2003			etx = SSP_TX_LSB;
2004		} else {
2005			tmp = SSP_RX_MSB;
2006			etx = SSP_TX_MSB;
2007		}
2008		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
2009		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2010		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2011			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2012		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2013			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2014	} else {
2015		SSP_WRITE_BITS(chip->cr0, bits - 1,
2016			       SSP_CR0_MASK_DSS, 0);
2017		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2018			       SSP_CR0_MASK_FRF, 4);
2019	}
2020
2021	/* Stuff that is common for all versions */
2022	if (spi->mode & SPI_CPOL)
2023		tmp = SSP_CLK_POL_IDLE_HIGH;
2024	else
2025		tmp = SSP_CLK_POL_IDLE_LOW;
2026	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2027
2028	if (spi->mode & SPI_CPHA)
2029		tmp = SSP_CLK_SECOND_EDGE;
2030	else
2031		tmp = SSP_CLK_FIRST_EDGE;
2032	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2033
2034	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2035	/* Loopback is available on all versions except PL023 */
2036	if (pl022->vendor->loopback) {
2037		if (spi->mode & SPI_LOOP)
2038			tmp = LOOPBACK_ENABLED;
2039		else
2040			tmp = LOOPBACK_DISABLED;
2041		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2042	}
2043	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2044	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2045	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2046		3);
2047
2048	/* Save controller_state */
2049	spi_set_ctldata(spi, chip);
2050	return status;
2051 err_config_params:
2052	spi_set_ctldata(spi, NULL);
2053	kfree(chip);
2054	return status;
2055}
2056
2057/**
2058 * pl022_cleanup - cleanup function registered to SPI master framework
2059 * @spi: spi device which is requesting cleanup
2060 *
2061 * This function is registered to the SPI framework for this SPI master
2062 * controller. It will free the runtime state of chip.
2063 */
2064static void pl022_cleanup(struct spi_device *spi)
2065{
2066	struct chip_data *chip = spi_get_ctldata(spi);
2067
2068	spi_set_ctldata(spi, NULL);
2069	kfree(chip);
2070}
2071
2072static struct pl022_ssp_controller *
2073pl022_platform_data_dt_get(struct device *dev)
2074{
2075	struct device_node *np = dev->of_node;
2076	struct pl022_ssp_controller *pd;
2077	u32 tmp;
2078
2079	if (!np) {
2080		dev_err(dev, "no dt node defined\n");
2081		return NULL;
2082	}
2083
2084	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2085	if (!pd)
2086		return NULL;
2087
2088	pd->bus_id = -1;
2089	pd->enable_dma = 1;
2090	of_property_read_u32(np, "num-cs", &tmp);
2091	pd->num_chipselect = tmp;
2092	of_property_read_u32(np, "pl022,autosuspend-delay",
2093			     &pd->autosuspend_delay);
2094	pd->rt = of_property_read_bool(np, "pl022,rt");
2095
2096	return pd;
2097}
2098
2099static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2100{
2101	struct device *dev = &adev->dev;
2102	struct pl022_ssp_controller *platform_info =
2103			dev_get_platdata(&adev->dev);
2104	struct spi_master *master;
2105	struct pl022 *pl022 = NULL;	/*Data for this driver */
2106	struct device_node *np = adev->dev.of_node;
2107	int status = 0, i, num_cs;
2108
2109	dev_info(&adev->dev,
2110		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2111	if (!platform_info && IS_ENABLED(CONFIG_OF))
2112		platform_info = pl022_platform_data_dt_get(dev);
2113
2114	if (!platform_info) {
2115		dev_err(dev, "probe: no platform data defined\n");
2116		return -ENODEV;
2117	}
2118
2119	if (platform_info->num_chipselect) {
2120		num_cs = platform_info->num_chipselect;
2121	} else {
2122		dev_err(dev, "probe: no chip select defined\n");
2123		return -ENODEV;
2124	}
2125
2126	/* Allocate master with space for data */
2127	master = spi_alloc_master(dev, sizeof(struct pl022));
2128	if (master == NULL) {
2129		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2130		return -ENOMEM;
2131	}
2132
2133	pl022 = spi_master_get_devdata(master);
2134	pl022->master = master;
2135	pl022->master_info = platform_info;
2136	pl022->adev = adev;
2137	pl022->vendor = id->data;
2138	pl022->chipselects = devm_kzalloc(dev, num_cs * sizeof(int),
2139					  GFP_KERNEL);
2140	if (!pl022->chipselects) {
2141		status = -ENOMEM;
2142		goto err_no_mem;
2143	}
2144
2145	/*
2146	 * Bus Number Which has been Assigned to this SSP controller
2147	 * on this board
2148	 */
2149	master->bus_num = platform_info->bus_id;
2150	master->num_chipselect = num_cs;
2151	master->cleanup = pl022_cleanup;
2152	master->setup = pl022_setup;
2153	master->auto_runtime_pm = true;
2154	master->transfer_one_message = pl022_transfer_one_message;
2155	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2156	master->rt = platform_info->rt;
2157	master->dev.of_node = dev->of_node;
2158
2159	if (platform_info->num_chipselect && platform_info->chipselects) {
2160		for (i = 0; i < num_cs; i++)
2161			pl022->chipselects[i] = platform_info->chipselects[i];
2162	} else if (pl022->vendor->internal_cs_ctrl) {
2163		for (i = 0; i < num_cs; i++)
2164			pl022->chipselects[i] = i;
2165	} else if (IS_ENABLED(CONFIG_OF)) {
2166		for (i = 0; i < num_cs; i++) {
2167			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2168
2169			if (cs_gpio == -EPROBE_DEFER) {
2170				status = -EPROBE_DEFER;
2171				goto err_no_gpio;
2172			}
2173
2174			pl022->chipselects[i] = cs_gpio;
2175
2176			if (gpio_is_valid(cs_gpio)) {
2177				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2178					dev_err(&adev->dev,
2179						"could not request %d gpio\n",
2180						cs_gpio);
2181				else if (gpio_direction_output(cs_gpio, 1))
2182					dev_err(&adev->dev,
2183						"could not set gpio %d as output\n",
2184						cs_gpio);
2185			}
2186		}
2187	}
2188
2189	/*
2190	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2191	 * always MS bit first on the original pl022.
2192	 */
2193	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2194	if (pl022->vendor->extended_cr)
2195		master->mode_bits |= SPI_LSB_FIRST;
2196
2197	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2198
2199	status = amba_request_regions(adev, NULL);
2200	if (status)
2201		goto err_no_ioregion;
2202
2203	pl022->phybase = adev->res.start;
2204	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2205				       resource_size(&adev->res));
2206	if (pl022->virtbase == NULL) {
2207		status = -ENOMEM;
2208		goto err_no_ioremap;
2209	}
2210	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
2211		&adev->res.start, pl022->virtbase);
2212
2213	pl022->clk = devm_clk_get(&adev->dev, NULL);
2214	if (IS_ERR(pl022->clk)) {
2215		status = PTR_ERR(pl022->clk);
2216		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2217		goto err_no_clk;
2218	}
2219
2220	status = clk_prepare_enable(pl022->clk);
2221	if (status) {
2222		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2223		goto err_no_clk_en;
2224	}
2225
2226	/* Initialize transfer pump */
2227	tasklet_init(&pl022->pump_transfers, pump_transfers,
2228		     (unsigned long)pl022);
2229
2230	/* Disable SSP */
2231	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2232	       SSP_CR1(pl022->virtbase));
2233	load_ssp_default_config(pl022);
2234
2235	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2236				  0, "pl022", pl022);
2237	if (status < 0) {
2238		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2239		goto err_no_irq;
2240	}
2241
2242	/* Get DMA channels, try autoconfiguration first */
2243	status = pl022_dma_autoprobe(pl022);
2244	if (status == -EPROBE_DEFER) {
2245		dev_dbg(dev, "deferring probe to get DMA channel\n");
2246		goto err_no_irq;
2247	}
2248
2249	/* If that failed, use channels from platform_info */
2250	if (status == 0)
2251		platform_info->enable_dma = 1;
2252	else if (platform_info->enable_dma) {
2253		status = pl022_dma_probe(pl022);
2254		if (status != 0)
2255			platform_info->enable_dma = 0;
2256	}
2257
2258	/* Register with the SPI framework */
2259	amba_set_drvdata(adev, pl022);
2260	status = devm_spi_register_master(&adev->dev, master);
2261	if (status != 0) {
2262		dev_err(&adev->dev,
2263			"probe - problem registering spi master\n");
2264		goto err_spi_register;
2265	}
2266	dev_dbg(dev, "probe succeeded\n");
2267
2268	/* let runtime pm put suspend */
2269	if (platform_info->autosuspend_delay > 0) {
2270		dev_info(&adev->dev,
2271			"will use autosuspend for runtime pm, delay %dms\n",
2272			platform_info->autosuspend_delay);
2273		pm_runtime_set_autosuspend_delay(dev,
2274			platform_info->autosuspend_delay);
2275		pm_runtime_use_autosuspend(dev);
2276	}
2277	pm_runtime_put(dev);
2278
2279	return 0;
2280
2281 err_spi_register:
2282	if (platform_info->enable_dma)
2283		pl022_dma_remove(pl022);
2284 err_no_irq:
2285	clk_disable_unprepare(pl022->clk);
2286 err_no_clk_en:
2287 err_no_clk:
2288 err_no_ioremap:
2289	amba_release_regions(adev);
2290 err_no_ioregion:
2291 err_no_gpio:
2292 err_no_mem:
2293	spi_master_put(master);
2294	return status;
2295}
2296
2297static int
2298pl022_remove(struct amba_device *adev)
2299{
2300	struct pl022 *pl022 = amba_get_drvdata(adev);
2301
2302	if (!pl022)
2303		return 0;
2304
2305	/*
2306	 * undo pm_runtime_put() in probe.  I assume that we're not
2307	 * accessing the primecell here.
2308	 */
2309	pm_runtime_get_noresume(&adev->dev);
2310
2311	load_ssp_default_config(pl022);
2312	if (pl022->master_info->enable_dma)
2313		pl022_dma_remove(pl022);
2314
2315	clk_disable_unprepare(pl022->clk);
2316	amba_release_regions(adev);
2317	tasklet_disable(&pl022->pump_transfers);
2318	return 0;
2319}
2320
2321#ifdef CONFIG_PM_SLEEP
2322static int pl022_suspend(struct device *dev)
2323{
2324	struct pl022 *pl022 = dev_get_drvdata(dev);
2325	int ret;
2326
2327	ret = spi_master_suspend(pl022->master);
2328	if (ret) {
2329		dev_warn(dev, "cannot suspend master\n");
2330		return ret;
2331	}
2332
2333	ret = pm_runtime_force_suspend(dev);
2334	if (ret) {
2335		spi_master_resume(pl022->master);
2336		return ret;
2337	}
2338
2339	pinctrl_pm_select_sleep_state(dev);
2340
2341	dev_dbg(dev, "suspended\n");
2342	return 0;
2343}
2344
2345static int pl022_resume(struct device *dev)
2346{
2347	struct pl022 *pl022 = dev_get_drvdata(dev);
2348	int ret;
2349
2350	ret = pm_runtime_force_resume(dev);
2351	if (ret)
2352		dev_err(dev, "problem resuming\n");
2353
2354	/* Start the queue running */
2355	ret = spi_master_resume(pl022->master);
2356	if (ret)
2357		dev_err(dev, "problem starting queue (%d)\n", ret);
2358	else
2359		dev_dbg(dev, "resumed\n");
2360
2361	return ret;
2362}
2363#endif
2364
2365#ifdef CONFIG_PM
2366static int pl022_runtime_suspend(struct device *dev)
2367{
2368	struct pl022 *pl022 = dev_get_drvdata(dev);
2369
2370	clk_disable_unprepare(pl022->clk);
2371	pinctrl_pm_select_idle_state(dev);
2372
2373	return 0;
2374}
2375
2376static int pl022_runtime_resume(struct device *dev)
2377{
2378	struct pl022 *pl022 = dev_get_drvdata(dev);
2379
2380	pinctrl_pm_select_default_state(dev);
2381	clk_prepare_enable(pl022->clk);
2382
2383	return 0;
2384}
2385#endif
2386
2387static const struct dev_pm_ops pl022_dev_pm_ops = {
2388	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2389	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2390};
2391
2392static struct vendor_data vendor_arm = {
2393	.fifodepth = 8,
2394	.max_bpw = 16,
2395	.unidir = false,
2396	.extended_cr = false,
2397	.pl023 = false,
2398	.loopback = true,
2399	.internal_cs_ctrl = false,
2400};
2401
2402static struct vendor_data vendor_st = {
2403	.fifodepth = 32,
2404	.max_bpw = 32,
2405	.unidir = false,
2406	.extended_cr = true,
2407	.pl023 = false,
2408	.loopback = true,
2409	.internal_cs_ctrl = false,
2410};
2411
2412static struct vendor_data vendor_st_pl023 = {
2413	.fifodepth = 32,
2414	.max_bpw = 32,
2415	.unidir = false,
2416	.extended_cr = true,
2417	.pl023 = true,
2418	.loopback = false,
2419	.internal_cs_ctrl = false,
2420};
2421
2422static struct vendor_data vendor_lsi = {
2423	.fifodepth = 8,
2424	.max_bpw = 16,
2425	.unidir = false,
2426	.extended_cr = false,
2427	.pl023 = false,
2428	.loopback = true,
2429	.internal_cs_ctrl = true,
2430};
2431
2432static struct amba_id pl022_ids[] = {
2433	{
2434		/*
2435		 * ARM PL022 variant, this has a 16bit wide
2436		 * and 8 locations deep TX/RX FIFO
2437		 */
2438		.id	= 0x00041022,
2439		.mask	= 0x000fffff,
2440		.data	= &vendor_arm,
2441	},
2442	{
2443		/*
2444		 * ST Micro derivative, this has 32bit wide
2445		 * and 32 locations deep TX/RX FIFO
2446		 */
2447		.id	= 0x01080022,
2448		.mask	= 0xffffffff,
2449		.data	= &vendor_st,
2450	},
2451	{
2452		/*
2453		 * ST-Ericsson derivative "PL023" (this is not
2454		 * an official ARM number), this is a PL022 SSP block
2455		 * stripped to SPI mode only, it has 32bit wide
2456		 * and 32 locations deep TX/RX FIFO but no extended
2457		 * CR0/CR1 register
2458		 */
2459		.id	= 0x00080023,
2460		.mask	= 0xffffffff,
2461		.data	= &vendor_st_pl023,
2462	},
2463	{
2464		/*
2465		 * PL022 variant that has a chip select control register whih
2466		 * allows control of 5 output signals nCS[0:4].
2467		 */
2468		.id	= 0x000b6022,
2469		.mask	= 0x000fffff,
2470		.data	= &vendor_lsi,
2471	},
2472	{ 0, 0 },
2473};
2474
2475MODULE_DEVICE_TABLE(amba, pl022_ids);
2476
2477static struct amba_driver pl022_driver = {
2478	.drv = {
2479		.name	= "ssp-pl022",
2480		.pm	= &pl022_dev_pm_ops,
2481	},
2482	.id_table	= pl022_ids,
2483	.probe		= pl022_probe,
2484	.remove		= pl022_remove,
2485};
2486
2487static int __init pl022_init(void)
2488{
2489	return amba_driver_register(&pl022_driver);
2490}
2491subsys_initcall(pl022_init);
2492
2493static void __exit pl022_exit(void)
2494{
2495	amba_driver_unregister(&pl022_driver);
2496}
2497module_exit(pl022_exit);
2498
2499MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2500MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2501MODULE_LICENSE("GPL");
v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * A driver for the ARM PL022 PrimeCell SSP/SPI bus master.
   4 *
   5 * Copyright (C) 2008-2012 ST-Ericsson AB
   6 * Copyright (C) 2006 STMicroelectronics Pvt. Ltd.
   7 *
   8 * Author: Linus Walleij <linus.walleij@stericsson.com>
   9 *
  10 * Initial version inspired by:
  11 *	linux-2.6.17-rc3-mm1/drivers/spi/pxa2xx_spi.c
  12 * Initial adoption to PL022 by:
  13 *      Sachin Verma <sachin.verma@st.com>
 
 
 
 
 
 
 
 
 
 
  14 */
  15
  16#include <linux/init.h>
  17#include <linux/module.h>
  18#include <linux/device.h>
  19#include <linux/ioport.h>
  20#include <linux/errno.h>
  21#include <linux/interrupt.h>
  22#include <linux/spi/spi.h>
  23#include <linux/delay.h>
  24#include <linux/clk.h>
  25#include <linux/err.h>
  26#include <linux/amba/bus.h>
  27#include <linux/amba/pl022.h>
  28#include <linux/io.h>
  29#include <linux/slab.h>
  30#include <linux/dmaengine.h>
  31#include <linux/dma-mapping.h>
  32#include <linux/scatterlist.h>
  33#include <linux/pm_runtime.h>
  34#include <linux/gpio.h>
  35#include <linux/of_gpio.h>
  36#include <linux/pinctrl/consumer.h>
  37
  38/*
  39 * This macro is used to define some register default values.
  40 * reg is masked with mask, the OR:ed with an (again masked)
  41 * val shifted sb steps to the left.
  42 */
  43#define SSP_WRITE_BITS(reg, val, mask, sb) \
  44 ((reg) = (((reg) & ~(mask)) | (((val)<<(sb)) & (mask))))
  45
  46/*
  47 * This macro is also used to define some default values.
  48 * It will just shift val by sb steps to the left and mask
  49 * the result with mask.
  50 */
  51#define GEN_MASK_BITS(val, mask, sb) \
  52 (((val)<<(sb)) & (mask))
  53
  54#define DRIVE_TX		0
  55#define DO_NOT_DRIVE_TX		1
  56
  57#define DO_NOT_QUEUE_DMA	0
  58#define QUEUE_DMA		1
  59
  60#define RX_TRANSFER		1
  61#define TX_TRANSFER		2
  62
  63/*
  64 * Macros to access SSP Registers with their offsets
  65 */
  66#define SSP_CR0(r)	(r + 0x000)
  67#define SSP_CR1(r)	(r + 0x004)
  68#define SSP_DR(r)	(r + 0x008)
  69#define SSP_SR(r)	(r + 0x00C)
  70#define SSP_CPSR(r)	(r + 0x010)
  71#define SSP_IMSC(r)	(r + 0x014)
  72#define SSP_RIS(r)	(r + 0x018)
  73#define SSP_MIS(r)	(r + 0x01C)
  74#define SSP_ICR(r)	(r + 0x020)
  75#define SSP_DMACR(r)	(r + 0x024)
  76#define SSP_CSR(r)	(r + 0x030) /* vendor extension */
  77#define SSP_ITCR(r)	(r + 0x080)
  78#define SSP_ITIP(r)	(r + 0x084)
  79#define SSP_ITOP(r)	(r + 0x088)
  80#define SSP_TDR(r)	(r + 0x08C)
  81
  82#define SSP_PID0(r)	(r + 0xFE0)
  83#define SSP_PID1(r)	(r + 0xFE4)
  84#define SSP_PID2(r)	(r + 0xFE8)
  85#define SSP_PID3(r)	(r + 0xFEC)
  86
  87#define SSP_CID0(r)	(r + 0xFF0)
  88#define SSP_CID1(r)	(r + 0xFF4)
  89#define SSP_CID2(r)	(r + 0xFF8)
  90#define SSP_CID3(r)	(r + 0xFFC)
  91
  92/*
  93 * SSP Control Register 0  - SSP_CR0
  94 */
  95#define SSP_CR0_MASK_DSS	(0x0FUL << 0)
  96#define SSP_CR0_MASK_FRF	(0x3UL << 4)
  97#define SSP_CR0_MASK_SPO	(0x1UL << 6)
  98#define SSP_CR0_MASK_SPH	(0x1UL << 7)
  99#define SSP_CR0_MASK_SCR	(0xFFUL << 8)
 100
 101/*
 102 * The ST version of this block moves som bits
 103 * in SSP_CR0 and extends it to 32 bits
 104 */
 105#define SSP_CR0_MASK_DSS_ST	(0x1FUL << 0)
 106#define SSP_CR0_MASK_HALFDUP_ST	(0x1UL << 5)
 107#define SSP_CR0_MASK_CSS_ST	(0x1FUL << 16)
 108#define SSP_CR0_MASK_FRF_ST	(0x3UL << 21)
 109
 110/*
 111 * SSP Control Register 0  - SSP_CR1
 112 */
 113#define SSP_CR1_MASK_LBM	(0x1UL << 0)
 114#define SSP_CR1_MASK_SSE	(0x1UL << 1)
 115#define SSP_CR1_MASK_MS		(0x1UL << 2)
 116#define SSP_CR1_MASK_SOD	(0x1UL << 3)
 117
 118/*
 119 * The ST version of this block adds some bits
 120 * in SSP_CR1
 121 */
 122#define SSP_CR1_MASK_RENDN_ST	(0x1UL << 4)
 123#define SSP_CR1_MASK_TENDN_ST	(0x1UL << 5)
 124#define SSP_CR1_MASK_MWAIT_ST	(0x1UL << 6)
 125#define SSP_CR1_MASK_RXIFLSEL_ST (0x7UL << 7)
 126#define SSP_CR1_MASK_TXIFLSEL_ST (0x7UL << 10)
 127/* This one is only in the PL023 variant */
 128#define SSP_CR1_MASK_FBCLKDEL_ST (0x7UL << 13)
 129
 130/*
 131 * SSP Status Register - SSP_SR
 132 */
 133#define SSP_SR_MASK_TFE		(0x1UL << 0) /* Transmit FIFO empty */
 134#define SSP_SR_MASK_TNF		(0x1UL << 1) /* Transmit FIFO not full */
 135#define SSP_SR_MASK_RNE		(0x1UL << 2) /* Receive FIFO not empty */
 136#define SSP_SR_MASK_RFF		(0x1UL << 3) /* Receive FIFO full */
 137#define SSP_SR_MASK_BSY		(0x1UL << 4) /* Busy Flag */
 138
 139/*
 140 * SSP Clock Prescale Register  - SSP_CPSR
 141 */
 142#define SSP_CPSR_MASK_CPSDVSR	(0xFFUL << 0)
 143
 144/*
 145 * SSP Interrupt Mask Set/Clear Register - SSP_IMSC
 146 */
 147#define SSP_IMSC_MASK_RORIM (0x1UL << 0) /* Receive Overrun Interrupt mask */
 148#define SSP_IMSC_MASK_RTIM  (0x1UL << 1) /* Receive timeout Interrupt mask */
 149#define SSP_IMSC_MASK_RXIM  (0x1UL << 2) /* Receive FIFO Interrupt mask */
 150#define SSP_IMSC_MASK_TXIM  (0x1UL << 3) /* Transmit FIFO Interrupt mask */
 151
 152/*
 153 * SSP Raw Interrupt Status Register - SSP_RIS
 154 */
 155/* Receive Overrun Raw Interrupt status */
 156#define SSP_RIS_MASK_RORRIS		(0x1UL << 0)
 157/* Receive Timeout Raw Interrupt status */
 158#define SSP_RIS_MASK_RTRIS		(0x1UL << 1)
 159/* Receive FIFO Raw Interrupt status */
 160#define SSP_RIS_MASK_RXRIS		(0x1UL << 2)
 161/* Transmit FIFO Raw Interrupt status */
 162#define SSP_RIS_MASK_TXRIS		(0x1UL << 3)
 163
 164/*
 165 * SSP Masked Interrupt Status Register - SSP_MIS
 166 */
 167/* Receive Overrun Masked Interrupt status */
 168#define SSP_MIS_MASK_RORMIS		(0x1UL << 0)
 169/* Receive Timeout Masked Interrupt status */
 170#define SSP_MIS_MASK_RTMIS		(0x1UL << 1)
 171/* Receive FIFO Masked Interrupt status */
 172#define SSP_MIS_MASK_RXMIS		(0x1UL << 2)
 173/* Transmit FIFO Masked Interrupt status */
 174#define SSP_MIS_MASK_TXMIS		(0x1UL << 3)
 175
 176/*
 177 * SSP Interrupt Clear Register - SSP_ICR
 178 */
 179/* Receive Overrun Raw Clear Interrupt bit */
 180#define SSP_ICR_MASK_RORIC		(0x1UL << 0)
 181/* Receive Timeout Clear Interrupt bit */
 182#define SSP_ICR_MASK_RTIC		(0x1UL << 1)
 183
 184/*
 185 * SSP DMA Control Register - SSP_DMACR
 186 */
 187/* Receive DMA Enable bit */
 188#define SSP_DMACR_MASK_RXDMAE		(0x1UL << 0)
 189/* Transmit DMA Enable bit */
 190#define SSP_DMACR_MASK_TXDMAE		(0x1UL << 1)
 191
 192/*
 193 * SSP Chip Select Control Register - SSP_CSR
 194 * (vendor extension)
 195 */
 196#define SSP_CSR_CSVALUE_MASK		(0x1FUL << 0)
 197
 198/*
 199 * SSP Integration Test control Register - SSP_ITCR
 200 */
 201#define SSP_ITCR_MASK_ITEN		(0x1UL << 0)
 202#define SSP_ITCR_MASK_TESTFIFO		(0x1UL << 1)
 203
 204/*
 205 * SSP Integration Test Input Register - SSP_ITIP
 206 */
 207#define ITIP_MASK_SSPRXD		 (0x1UL << 0)
 208#define ITIP_MASK_SSPFSSIN		 (0x1UL << 1)
 209#define ITIP_MASK_SSPCLKIN		 (0x1UL << 2)
 210#define ITIP_MASK_RXDMAC		 (0x1UL << 3)
 211#define ITIP_MASK_TXDMAC		 (0x1UL << 4)
 212#define ITIP_MASK_SSPTXDIN		 (0x1UL << 5)
 213
 214/*
 215 * SSP Integration Test output Register - SSP_ITOP
 216 */
 217#define ITOP_MASK_SSPTXD		 (0x1UL << 0)
 218#define ITOP_MASK_SSPFSSOUT		 (0x1UL << 1)
 219#define ITOP_MASK_SSPCLKOUT		 (0x1UL << 2)
 220#define ITOP_MASK_SSPOEn		 (0x1UL << 3)
 221#define ITOP_MASK_SSPCTLOEn		 (0x1UL << 4)
 222#define ITOP_MASK_RORINTR		 (0x1UL << 5)
 223#define ITOP_MASK_RTINTR		 (0x1UL << 6)
 224#define ITOP_MASK_RXINTR		 (0x1UL << 7)
 225#define ITOP_MASK_TXINTR		 (0x1UL << 8)
 226#define ITOP_MASK_INTR			 (0x1UL << 9)
 227#define ITOP_MASK_RXDMABREQ		 (0x1UL << 10)
 228#define ITOP_MASK_RXDMASREQ		 (0x1UL << 11)
 229#define ITOP_MASK_TXDMABREQ		 (0x1UL << 12)
 230#define ITOP_MASK_TXDMASREQ		 (0x1UL << 13)
 231
 232/*
 233 * SSP Test Data Register - SSP_TDR
 234 */
 235#define TDR_MASK_TESTDATA		(0xFFFFFFFF)
 236
 237/*
 238 * Message State
 239 * we use the spi_message.state (void *) pointer to
 240 * hold a single state value, that's why all this
 241 * (void *) casting is done here.
 242 */
 243#define STATE_START			((void *) 0)
 244#define STATE_RUNNING			((void *) 1)
 245#define STATE_DONE			((void *) 2)
 246#define STATE_ERROR			((void *) -1)
 247#define STATE_TIMEOUT			((void *) -2)
 248
 249/*
 250 * SSP State - Whether Enabled or Disabled
 251 */
 252#define SSP_DISABLED			(0)
 253#define SSP_ENABLED			(1)
 254
 255/*
 256 * SSP DMA State - Whether DMA Enabled or Disabled
 257 */
 258#define SSP_DMA_DISABLED		(0)
 259#define SSP_DMA_ENABLED			(1)
 260
 261/*
 262 * SSP Clock Defaults
 263 */
 264#define SSP_DEFAULT_CLKRATE 0x2
 265#define SSP_DEFAULT_PRESCALE 0x40
 266
 267/*
 268 * SSP Clock Parameter ranges
 269 */
 270#define CPSDVR_MIN 0x02
 271#define CPSDVR_MAX 0xFE
 272#define SCR_MIN 0x00
 273#define SCR_MAX 0xFF
 274
 275/*
 276 * SSP Interrupt related Macros
 277 */
 278#define DEFAULT_SSP_REG_IMSC  0x0UL
 279#define DISABLE_ALL_INTERRUPTS DEFAULT_SSP_REG_IMSC
 280#define ENABLE_ALL_INTERRUPTS ( \
 281	SSP_IMSC_MASK_RORIM | \
 282	SSP_IMSC_MASK_RTIM | \
 283	SSP_IMSC_MASK_RXIM | \
 284	SSP_IMSC_MASK_TXIM \
 285)
 286
 287#define CLEAR_ALL_INTERRUPTS  0x3
 288
 289#define SPI_POLLING_TIMEOUT 1000
 290
 291/*
 292 * The type of reading going on on this chip
 293 */
 294enum ssp_reading {
 295	READING_NULL,
 296	READING_U8,
 297	READING_U16,
 298	READING_U32
 299};
 300
 301/**
 302 * The type of writing going on on this chip
 303 */
 304enum ssp_writing {
 305	WRITING_NULL,
 306	WRITING_U8,
 307	WRITING_U16,
 308	WRITING_U32
 309};
 310
 311/**
 312 * struct vendor_data - vendor-specific config parameters
 313 * for PL022 derivates
 314 * @fifodepth: depth of FIFOs (both)
 315 * @max_bpw: maximum number of bits per word
 316 * @unidir: supports unidirection transfers
 317 * @extended_cr: 32 bit wide control register 0 with extra
 318 * features and extra features in CR1 as found in the ST variants
 319 * @pl023: supports a subset of the ST extensions called "PL023"
 320 * @internal_cs_ctrl: supports chip select control register
 321 */
 322struct vendor_data {
 323	int fifodepth;
 324	int max_bpw;
 325	bool unidir;
 326	bool extended_cr;
 327	bool pl023;
 328	bool loopback;
 329	bool internal_cs_ctrl;
 330};
 331
 332/**
 333 * struct pl022 - This is the private SSP driver data structure
 334 * @adev: AMBA device model hookup
 335 * @vendor: vendor data for the IP block
 336 * @phybase: the physical memory where the SSP device resides
 337 * @virtbase: the virtual memory where the SSP is mapped
 338 * @clk: outgoing clock "SPICLK" for the SPI bus
 339 * @master: SPI framework hookup
 340 * @master_info: controller-specific data from machine setup
 341 * @pump_transfers: Tasklet used in Interrupt Transfer mode
 342 * @cur_msg: Pointer to current spi_message being processed
 343 * @cur_transfer: Pointer to current spi_transfer
 344 * @cur_chip: pointer to current clients chip(assigned from controller_state)
 345 * @next_msg_cs_active: the next message in the queue has been examined
 346 *  and it was found that it uses the same chip select as the previous
 347 *  message, so we left it active after the previous transfer, and it's
 348 *  active already.
 349 * @tx: current position in TX buffer to be read
 350 * @tx_end: end position in TX buffer to be read
 351 * @rx: current position in RX buffer to be written
 352 * @rx_end: end position in RX buffer to be written
 353 * @read: the type of read currently going on
 354 * @write: the type of write currently going on
 355 * @exp_fifo_level: expected FIFO level
 356 * @dma_rx_channel: optional channel for RX DMA
 357 * @dma_tx_channel: optional channel for TX DMA
 358 * @sgt_rx: scattertable for the RX transfer
 359 * @sgt_tx: scattertable for the TX transfer
 360 * @dummypage: a dummy page used for driving data on the bus with DMA
 361 * @cur_cs: current chip select (gpio)
 362 * @chipselects: list of chipselects (gpios)
 363 */
 364struct pl022 {
 365	struct amba_device		*adev;
 366	struct vendor_data		*vendor;
 367	resource_size_t			phybase;
 368	void __iomem			*virtbase;
 369	struct clk			*clk;
 370	struct spi_master		*master;
 371	struct pl022_ssp_controller	*master_info;
 372	/* Message per-transfer pump */
 373	struct tasklet_struct		pump_transfers;
 374	struct spi_message		*cur_msg;
 375	struct spi_transfer		*cur_transfer;
 376	struct chip_data		*cur_chip;
 377	bool				next_msg_cs_active;
 378	void				*tx;
 379	void				*tx_end;
 380	void				*rx;
 381	void				*rx_end;
 382	enum ssp_reading		read;
 383	enum ssp_writing		write;
 384	u32				exp_fifo_level;
 385	enum ssp_rx_level_trig		rx_lev_trig;
 386	enum ssp_tx_level_trig		tx_lev_trig;
 387	/* DMA settings */
 388#ifdef CONFIG_DMA_ENGINE
 389	struct dma_chan			*dma_rx_channel;
 390	struct dma_chan			*dma_tx_channel;
 391	struct sg_table			sgt_rx;
 392	struct sg_table			sgt_tx;
 393	char				*dummypage;
 394	bool				dma_running;
 395#endif
 396	int cur_cs;
 397	int *chipselects;
 398};
 399
 400/**
 401 * struct chip_data - To maintain runtime state of SSP for each client chip
 402 * @cr0: Value of control register CR0 of SSP - on later ST variants this
 403 *       register is 32 bits wide rather than just 16
 404 * @cr1: Value of control register CR1 of SSP
 405 * @dmacr: Value of DMA control Register of SSP
 406 * @cpsr: Value of Clock prescale register
 407 * @n_bytes: how many bytes(power of 2) reqd for a given data width of client
 408 * @enable_dma: Whether to enable DMA or not
 409 * @read: function ptr to be used to read when doing xfer for this chip
 410 * @write: function ptr to be used to write when doing xfer for this chip
 411 * @cs_control: chip select callback provided by chip
 412 * @xfer_type: polling/interrupt/DMA
 413 *
 414 * Runtime state of the SSP controller, maintained per chip,
 415 * This would be set according to the current message that would be served
 416 */
 417struct chip_data {
 418	u32 cr0;
 419	u16 cr1;
 420	u16 dmacr;
 421	u16 cpsr;
 422	u8 n_bytes;
 423	bool enable_dma;
 424	enum ssp_reading read;
 425	enum ssp_writing write;
 426	void (*cs_control) (u32 command);
 427	int xfer_type;
 428};
 429
 430/**
 431 * null_cs_control - Dummy chip select function
 432 * @command: select/delect the chip
 433 *
 434 * If no chip select function is provided by client this is used as dummy
 435 * chip select
 436 */
 437static void null_cs_control(u32 command)
 438{
 439	pr_debug("pl022: dummy chip select control, CS=0x%x\n", command);
 440}
 441
 442/**
 443 * internal_cs_control - Control chip select signals via SSP_CSR.
 444 * @pl022: SSP driver private data structure
 445 * @command: select/delect the chip
 446 *
 447 * Used on controller with internal chip select control via SSP_CSR register
 448 * (vendor extension). Each of the 5 LSB in the register controls one chip
 449 * select signal.
 450 */
 451static void internal_cs_control(struct pl022 *pl022, u32 command)
 452{
 453	u32 tmp;
 454
 455	tmp = readw(SSP_CSR(pl022->virtbase));
 456	if (command == SSP_CHIP_SELECT)
 457		tmp &= ~BIT(pl022->cur_cs);
 458	else
 459		tmp |= BIT(pl022->cur_cs);
 460	writew(tmp, SSP_CSR(pl022->virtbase));
 461}
 462
 463static void pl022_cs_control(struct pl022 *pl022, u32 command)
 464{
 465	if (pl022->vendor->internal_cs_ctrl)
 466		internal_cs_control(pl022, command);
 467	else if (gpio_is_valid(pl022->cur_cs))
 468		gpio_set_value(pl022->cur_cs, command);
 469	else
 470		pl022->cur_chip->cs_control(command);
 471}
 472
 473/**
 474 * giveback - current spi_message is over, schedule next message and call
 475 * callback of this message. Assumes that caller already
 476 * set message->status; dma and pio irqs are blocked
 477 * @pl022: SSP driver private data structure
 478 */
 479static void giveback(struct pl022 *pl022)
 480{
 481	struct spi_transfer *last_transfer;
 482	pl022->next_msg_cs_active = false;
 483
 484	last_transfer = list_last_entry(&pl022->cur_msg->transfers,
 485					struct spi_transfer, transfer_list);
 486
 487	/* Delay if requested before any change in chip select */
 488	if (last_transfer->delay_usecs)
 489		/*
 490		 * FIXME: This runs in interrupt context.
 491		 * Is this really smart?
 492		 */
 493		udelay(last_transfer->delay_usecs);
 494
 495	if (!last_transfer->cs_change) {
 496		struct spi_message *next_msg;
 497
 498		/*
 499		 * cs_change was not set. We can keep the chip select
 500		 * enabled if there is message in the queue and it is
 501		 * for the same spi device.
 502		 *
 503		 * We cannot postpone this until pump_messages, because
 504		 * after calling msg->complete (below) the driver that
 505		 * sent the current message could be unloaded, which
 506		 * could invalidate the cs_control() callback...
 507		 */
 508		/* get a pointer to the next message, if any */
 509		next_msg = spi_get_next_queued_message(pl022->master);
 510
 511		/*
 512		 * see if the next and current messages point
 513		 * to the same spi device.
 514		 */
 515		if (next_msg && next_msg->spi != pl022->cur_msg->spi)
 516			next_msg = NULL;
 517		if (!next_msg || pl022->cur_msg->state == STATE_ERROR)
 518			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
 519		else
 520			pl022->next_msg_cs_active = true;
 521
 522	}
 523
 524	pl022->cur_msg = NULL;
 525	pl022->cur_transfer = NULL;
 526	pl022->cur_chip = NULL;
 527
 528	/* disable the SPI/SSP operation */
 529	writew((readw(SSP_CR1(pl022->virtbase)) &
 530		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
 531
 532	spi_finalize_current_message(pl022->master);
 533}
 534
 535/**
 536 * flush - flush the FIFO to reach a clean state
 537 * @pl022: SSP driver private data structure
 538 */
 539static int flush(struct pl022 *pl022)
 540{
 541	unsigned long limit = loops_per_jiffy << 1;
 542
 543	dev_dbg(&pl022->adev->dev, "flush\n");
 544	do {
 545		while (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 546			readw(SSP_DR(pl022->virtbase));
 547	} while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_BSY) && limit--);
 548
 549	pl022->exp_fifo_level = 0;
 550
 551	return limit;
 552}
 553
 554/**
 555 * restore_state - Load configuration of current chip
 556 * @pl022: SSP driver private data structure
 557 */
 558static void restore_state(struct pl022 *pl022)
 559{
 560	struct chip_data *chip = pl022->cur_chip;
 561
 562	if (pl022->vendor->extended_cr)
 563		writel(chip->cr0, SSP_CR0(pl022->virtbase));
 564	else
 565		writew(chip->cr0, SSP_CR0(pl022->virtbase));
 566	writew(chip->cr1, SSP_CR1(pl022->virtbase));
 567	writew(chip->dmacr, SSP_DMACR(pl022->virtbase));
 568	writew(chip->cpsr, SSP_CPSR(pl022->virtbase));
 569	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
 570	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
 571}
 572
 573/*
 574 * Default SSP Register Values
 575 */
 576#define DEFAULT_SSP_REG_CR0 ( \
 577	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS, 0)	| \
 578	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF, 4) | \
 579	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 580	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 581	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
 582)
 583
 584/* ST versions have slightly different bit layout */
 585#define DEFAULT_SSP_REG_CR0_ST ( \
 586	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
 587	GEN_MASK_BITS(SSP_MICROWIRE_CHANNEL_FULL_DUPLEX, SSP_CR0_MASK_HALFDUP_ST, 5) | \
 588	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 589	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 590	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) | \
 591	GEN_MASK_BITS(SSP_BITS_8, SSP_CR0_MASK_CSS_ST, 16)	| \
 592	GEN_MASK_BITS(SSP_INTERFACE_MOTOROLA_SPI, SSP_CR0_MASK_FRF_ST, 21) \
 593)
 594
 595/* The PL023 version is slightly different again */
 596#define DEFAULT_SSP_REG_CR0_ST_PL023 ( \
 597	GEN_MASK_BITS(SSP_DATA_BITS_12, SSP_CR0_MASK_DSS_ST, 0)	| \
 598	GEN_MASK_BITS(SSP_CLK_POL_IDLE_LOW, SSP_CR0_MASK_SPO, 6) | \
 599	GEN_MASK_BITS(SSP_CLK_SECOND_EDGE, SSP_CR0_MASK_SPH, 7) | \
 600	GEN_MASK_BITS(SSP_DEFAULT_CLKRATE, SSP_CR0_MASK_SCR, 8) \
 601)
 602
 603#define DEFAULT_SSP_REG_CR1 ( \
 604	GEN_MASK_BITS(LOOPBACK_DISABLED, SSP_CR1_MASK_LBM, 0) | \
 605	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
 606	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
 607	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) \
 608)
 609
 610/* ST versions extend this register to use all 16 bits */
 611#define DEFAULT_SSP_REG_CR1_ST ( \
 612	DEFAULT_SSP_REG_CR1 | \
 613	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
 614	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
 615	GEN_MASK_BITS(SSP_MWIRE_WAIT_ZERO, SSP_CR1_MASK_MWAIT_ST, 6) |\
 616	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
 617	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) \
 618)
 619
 620/*
 621 * The PL023 variant has further differences: no loopback mode, no microwire
 622 * support, and a new clock feedback delay setting.
 623 */
 624#define DEFAULT_SSP_REG_CR1_ST_PL023 ( \
 625	GEN_MASK_BITS(SSP_DISABLED, SSP_CR1_MASK_SSE, 1) | \
 626	GEN_MASK_BITS(SSP_MASTER, SSP_CR1_MASK_MS, 2) | \
 627	GEN_MASK_BITS(DO_NOT_DRIVE_TX, SSP_CR1_MASK_SOD, 3) | \
 628	GEN_MASK_BITS(SSP_RX_MSB, SSP_CR1_MASK_RENDN_ST, 4) | \
 629	GEN_MASK_BITS(SSP_TX_MSB, SSP_CR1_MASK_TENDN_ST, 5) | \
 630	GEN_MASK_BITS(SSP_RX_1_OR_MORE_ELEM, SSP_CR1_MASK_RXIFLSEL_ST, 7) | \
 631	GEN_MASK_BITS(SSP_TX_1_OR_MORE_EMPTY_LOC, SSP_CR1_MASK_TXIFLSEL_ST, 10) | \
 632	GEN_MASK_BITS(SSP_FEEDBACK_CLK_DELAY_NONE, SSP_CR1_MASK_FBCLKDEL_ST, 13) \
 633)
 634
 635#define DEFAULT_SSP_REG_CPSR ( \
 636	GEN_MASK_BITS(SSP_DEFAULT_PRESCALE, SSP_CPSR_MASK_CPSDVSR, 0) \
 637)
 638
 639#define DEFAULT_SSP_REG_DMACR (\
 640	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_RXDMAE, 0) | \
 641	GEN_MASK_BITS(SSP_DMA_DISABLED, SSP_DMACR_MASK_TXDMAE, 1) \
 642)
 643
 644/**
 645 * load_ssp_default_config - Load default configuration for SSP
 646 * @pl022: SSP driver private data structure
 647 */
 648static void load_ssp_default_config(struct pl022 *pl022)
 649{
 650	if (pl022->vendor->pl023) {
 651		writel(DEFAULT_SSP_REG_CR0_ST_PL023, SSP_CR0(pl022->virtbase));
 652		writew(DEFAULT_SSP_REG_CR1_ST_PL023, SSP_CR1(pl022->virtbase));
 653	} else if (pl022->vendor->extended_cr) {
 654		writel(DEFAULT_SSP_REG_CR0_ST, SSP_CR0(pl022->virtbase));
 655		writew(DEFAULT_SSP_REG_CR1_ST, SSP_CR1(pl022->virtbase));
 656	} else {
 657		writew(DEFAULT_SSP_REG_CR0, SSP_CR0(pl022->virtbase));
 658		writew(DEFAULT_SSP_REG_CR1, SSP_CR1(pl022->virtbase));
 659	}
 660	writew(DEFAULT_SSP_REG_DMACR, SSP_DMACR(pl022->virtbase));
 661	writew(DEFAULT_SSP_REG_CPSR, SSP_CPSR(pl022->virtbase));
 662	writew(DISABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
 663	writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
 664}
 665
 666/**
 667 * This will write to TX and read from RX according to the parameters
 668 * set in pl022.
 669 */
 670static void readwriter(struct pl022 *pl022)
 671{
 672
 673	/*
 674	 * The FIFO depth is different between primecell variants.
 675	 * I believe filling in too much in the FIFO might cause
 676	 * errons in 8bit wide transfers on ARM variants (just 8 words
 677	 * FIFO, means only 8x8 = 64 bits in FIFO) at least.
 678	 *
 679	 * To prevent this issue, the TX FIFO is only filled to the
 680	 * unused RX FIFO fill length, regardless of what the TX
 681	 * FIFO status flag indicates.
 682	 */
 683	dev_dbg(&pl022->adev->dev,
 684		"%s, rx: %p, rxend: %p, tx: %p, txend: %p\n",
 685		__func__, pl022->rx, pl022->rx_end, pl022->tx, pl022->tx_end);
 686
 687	/* Read as much as you can */
 688	while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 689	       && (pl022->rx < pl022->rx_end)) {
 690		switch (pl022->read) {
 691		case READING_NULL:
 692			readw(SSP_DR(pl022->virtbase));
 693			break;
 694		case READING_U8:
 695			*(u8 *) (pl022->rx) =
 696				readw(SSP_DR(pl022->virtbase)) & 0xFFU;
 697			break;
 698		case READING_U16:
 699			*(u16 *) (pl022->rx) =
 700				(u16) readw(SSP_DR(pl022->virtbase));
 701			break;
 702		case READING_U32:
 703			*(u32 *) (pl022->rx) =
 704				readl(SSP_DR(pl022->virtbase));
 705			break;
 706		}
 707		pl022->rx += (pl022->cur_chip->n_bytes);
 708		pl022->exp_fifo_level--;
 709	}
 710	/*
 711	 * Write as much as possible up to the RX FIFO size
 712	 */
 713	while ((pl022->exp_fifo_level < pl022->vendor->fifodepth)
 714	       && (pl022->tx < pl022->tx_end)) {
 715		switch (pl022->write) {
 716		case WRITING_NULL:
 717			writew(0x0, SSP_DR(pl022->virtbase));
 718			break;
 719		case WRITING_U8:
 720			writew(*(u8 *) (pl022->tx), SSP_DR(pl022->virtbase));
 721			break;
 722		case WRITING_U16:
 723			writew((*(u16 *) (pl022->tx)), SSP_DR(pl022->virtbase));
 724			break;
 725		case WRITING_U32:
 726			writel(*(u32 *) (pl022->tx), SSP_DR(pl022->virtbase));
 727			break;
 728		}
 729		pl022->tx += (pl022->cur_chip->n_bytes);
 730		pl022->exp_fifo_level++;
 731		/*
 732		 * This inner reader takes care of things appearing in the RX
 733		 * FIFO as we're transmitting. This will happen a lot since the
 734		 * clock starts running when you put things into the TX FIFO,
 735		 * and then things are continuously clocked into the RX FIFO.
 736		 */
 737		while ((readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RNE)
 738		       && (pl022->rx < pl022->rx_end)) {
 739			switch (pl022->read) {
 740			case READING_NULL:
 741				readw(SSP_DR(pl022->virtbase));
 742				break;
 743			case READING_U8:
 744				*(u8 *) (pl022->rx) =
 745					readw(SSP_DR(pl022->virtbase)) & 0xFFU;
 746				break;
 747			case READING_U16:
 748				*(u16 *) (pl022->rx) =
 749					(u16) readw(SSP_DR(pl022->virtbase));
 750				break;
 751			case READING_U32:
 752				*(u32 *) (pl022->rx) =
 753					readl(SSP_DR(pl022->virtbase));
 754				break;
 755			}
 756			pl022->rx += (pl022->cur_chip->n_bytes);
 757			pl022->exp_fifo_level--;
 758		}
 759	}
 760	/*
 761	 * When we exit here the TX FIFO should be full and the RX FIFO
 762	 * should be empty
 763	 */
 764}
 765
 766/**
 767 * next_transfer - Move to the Next transfer in the current spi message
 768 * @pl022: SSP driver private data structure
 769 *
 770 * This function moves though the linked list of spi transfers in the
 771 * current spi message and returns with the state of current spi
 772 * message i.e whether its last transfer is done(STATE_DONE) or
 773 * Next transfer is ready(STATE_RUNNING)
 774 */
 775static void *next_transfer(struct pl022 *pl022)
 776{
 777	struct spi_message *msg = pl022->cur_msg;
 778	struct spi_transfer *trans = pl022->cur_transfer;
 779
 780	/* Move to next transfer */
 781	if (trans->transfer_list.next != &msg->transfers) {
 782		pl022->cur_transfer =
 783		    list_entry(trans->transfer_list.next,
 784			       struct spi_transfer, transfer_list);
 785		return STATE_RUNNING;
 786	}
 787	return STATE_DONE;
 788}
 789
 790/*
 791 * This DMA functionality is only compiled in if we have
 792 * access to the generic DMA devices/DMA engine.
 793 */
 794#ifdef CONFIG_DMA_ENGINE
 795static void unmap_free_dma_scatter(struct pl022 *pl022)
 796{
 797	/* Unmap and free the SG tables */
 798	dma_unmap_sg(pl022->dma_tx_channel->device->dev, pl022->sgt_tx.sgl,
 799		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
 800	dma_unmap_sg(pl022->dma_rx_channel->device->dev, pl022->sgt_rx.sgl,
 801		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
 802	sg_free_table(&pl022->sgt_rx);
 803	sg_free_table(&pl022->sgt_tx);
 804}
 805
 806static void dma_callback(void *data)
 807{
 808	struct pl022 *pl022 = data;
 809	struct spi_message *msg = pl022->cur_msg;
 810
 811	BUG_ON(!pl022->sgt_rx.sgl);
 812
 813#ifdef VERBOSE_DEBUG
 814	/*
 815	 * Optionally dump out buffers to inspect contents, this is
 816	 * good if you want to convince yourself that the loopback
 817	 * read/write contents are the same, when adopting to a new
 818	 * DMA engine.
 819	 */
 820	{
 821		struct scatterlist *sg;
 822		unsigned int i;
 823
 824		dma_sync_sg_for_cpu(&pl022->adev->dev,
 825				    pl022->sgt_rx.sgl,
 826				    pl022->sgt_rx.nents,
 827				    DMA_FROM_DEVICE);
 828
 829		for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
 830			dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
 831			print_hex_dump(KERN_ERR, "SPI RX: ",
 832				       DUMP_PREFIX_OFFSET,
 833				       16,
 834				       1,
 835				       sg_virt(sg),
 836				       sg_dma_len(sg),
 837				       1);
 838		}
 839		for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
 840			dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
 841			print_hex_dump(KERN_ERR, "SPI TX: ",
 842				       DUMP_PREFIX_OFFSET,
 843				       16,
 844				       1,
 845				       sg_virt(sg),
 846				       sg_dma_len(sg),
 847				       1);
 848		}
 849	}
 850#endif
 851
 852	unmap_free_dma_scatter(pl022);
 853
 854	/* Update total bytes transferred */
 855	msg->actual_length += pl022->cur_transfer->len;
 
 
 
 856	/* Move to next transfer */
 857	msg->state = next_transfer(pl022);
 858	if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
 859		pl022_cs_control(pl022, SSP_CHIP_DESELECT);
 860	tasklet_schedule(&pl022->pump_transfers);
 861}
 862
 863static void setup_dma_scatter(struct pl022 *pl022,
 864			      void *buffer,
 865			      unsigned int length,
 866			      struct sg_table *sgtab)
 867{
 868	struct scatterlist *sg;
 869	int bytesleft = length;
 870	void *bufp = buffer;
 871	int mapbytes;
 872	int i;
 873
 874	if (buffer) {
 875		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
 876			/*
 877			 * If there are less bytes left than what fits
 878			 * in the current page (plus page alignment offset)
 879			 * we just feed in this, else we stuff in as much
 880			 * as we can.
 881			 */
 882			if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
 883				mapbytes = bytesleft;
 884			else
 885				mapbytes = PAGE_SIZE - offset_in_page(bufp);
 886			sg_set_page(sg, virt_to_page(bufp),
 887				    mapbytes, offset_in_page(bufp));
 888			bufp += mapbytes;
 889			bytesleft -= mapbytes;
 890			dev_dbg(&pl022->adev->dev,
 891				"set RX/TX target page @ %p, %d bytes, %d left\n",
 892				bufp, mapbytes, bytesleft);
 893		}
 894	} else {
 895		/* Map the dummy buffer on every page */
 896		for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
 897			if (bytesleft < PAGE_SIZE)
 898				mapbytes = bytesleft;
 899			else
 900				mapbytes = PAGE_SIZE;
 901			sg_set_page(sg, virt_to_page(pl022->dummypage),
 902				    mapbytes, 0);
 903			bytesleft -= mapbytes;
 904			dev_dbg(&pl022->adev->dev,
 905				"set RX/TX to dummy page %d bytes, %d left\n",
 906				mapbytes, bytesleft);
 907
 908		}
 909	}
 910	BUG_ON(bytesleft);
 911}
 912
 913/**
 914 * configure_dma - configures the channels for the next transfer
 915 * @pl022: SSP driver's private data structure
 916 */
 917static int configure_dma(struct pl022 *pl022)
 918{
 919	struct dma_slave_config rx_conf = {
 920		.src_addr = SSP_DR(pl022->phybase),
 921		.direction = DMA_DEV_TO_MEM,
 922		.device_fc = false,
 923	};
 924	struct dma_slave_config tx_conf = {
 925		.dst_addr = SSP_DR(pl022->phybase),
 926		.direction = DMA_MEM_TO_DEV,
 927		.device_fc = false,
 928	};
 929	unsigned int pages;
 930	int ret;
 931	int rx_sglen, tx_sglen;
 932	struct dma_chan *rxchan = pl022->dma_rx_channel;
 933	struct dma_chan *txchan = pl022->dma_tx_channel;
 934	struct dma_async_tx_descriptor *rxdesc;
 935	struct dma_async_tx_descriptor *txdesc;
 936
 937	/* Check that the channels are available */
 938	if (!rxchan || !txchan)
 939		return -ENODEV;
 940
 941	/*
 942	 * If supplied, the DMA burstsize should equal the FIFO trigger level.
 943	 * Notice that the DMA engine uses one-to-one mapping. Since we can
 944	 * not trigger on 2 elements this needs explicit mapping rather than
 945	 * calculation.
 946	 */
 947	switch (pl022->rx_lev_trig) {
 948	case SSP_RX_1_OR_MORE_ELEM:
 949		rx_conf.src_maxburst = 1;
 950		break;
 951	case SSP_RX_4_OR_MORE_ELEM:
 952		rx_conf.src_maxburst = 4;
 953		break;
 954	case SSP_RX_8_OR_MORE_ELEM:
 955		rx_conf.src_maxburst = 8;
 956		break;
 957	case SSP_RX_16_OR_MORE_ELEM:
 958		rx_conf.src_maxburst = 16;
 959		break;
 960	case SSP_RX_32_OR_MORE_ELEM:
 961		rx_conf.src_maxburst = 32;
 962		break;
 963	default:
 964		rx_conf.src_maxburst = pl022->vendor->fifodepth >> 1;
 965		break;
 966	}
 967
 968	switch (pl022->tx_lev_trig) {
 969	case SSP_TX_1_OR_MORE_EMPTY_LOC:
 970		tx_conf.dst_maxburst = 1;
 971		break;
 972	case SSP_TX_4_OR_MORE_EMPTY_LOC:
 973		tx_conf.dst_maxburst = 4;
 974		break;
 975	case SSP_TX_8_OR_MORE_EMPTY_LOC:
 976		tx_conf.dst_maxburst = 8;
 977		break;
 978	case SSP_TX_16_OR_MORE_EMPTY_LOC:
 979		tx_conf.dst_maxburst = 16;
 980		break;
 981	case SSP_TX_32_OR_MORE_EMPTY_LOC:
 982		tx_conf.dst_maxburst = 32;
 983		break;
 984	default:
 985		tx_conf.dst_maxburst = pl022->vendor->fifodepth >> 1;
 986		break;
 987	}
 988
 989	switch (pl022->read) {
 990	case READING_NULL:
 991		/* Use the same as for writing */
 992		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
 993		break;
 994	case READING_U8:
 995		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 996		break;
 997	case READING_U16:
 998		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 999		break;
1000	case READING_U32:
1001		rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1002		break;
1003	}
1004
1005	switch (pl022->write) {
1006	case WRITING_NULL:
1007		/* Use the same as for reading */
1008		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_UNDEFINED;
1009		break;
1010	case WRITING_U8:
1011		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
1012		break;
1013	case WRITING_U16:
1014		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
1015		break;
1016	case WRITING_U32:
1017		tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
1018		break;
1019	}
1020
1021	/* SPI pecularity: we need to read and write the same width */
1022	if (rx_conf.src_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1023		rx_conf.src_addr_width = tx_conf.dst_addr_width;
1024	if (tx_conf.dst_addr_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
1025		tx_conf.dst_addr_width = rx_conf.src_addr_width;
1026	BUG_ON(rx_conf.src_addr_width != tx_conf.dst_addr_width);
1027
1028	dmaengine_slave_config(rxchan, &rx_conf);
1029	dmaengine_slave_config(txchan, &tx_conf);
1030
1031	/* Create sglists for the transfers */
1032	pages = DIV_ROUND_UP(pl022->cur_transfer->len, PAGE_SIZE);
1033	dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
1034
1035	ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_ATOMIC);
1036	if (ret)
1037		goto err_alloc_rx_sg;
1038
1039	ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_ATOMIC);
1040	if (ret)
1041		goto err_alloc_tx_sg;
1042
1043	/* Fill in the scatterlists for the RX+TX buffers */
1044	setup_dma_scatter(pl022, pl022->rx,
1045			  pl022->cur_transfer->len, &pl022->sgt_rx);
1046	setup_dma_scatter(pl022, pl022->tx,
1047			  pl022->cur_transfer->len, &pl022->sgt_tx);
1048
1049	/* Map DMA buffers */
1050	rx_sglen = dma_map_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1051			   pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1052	if (!rx_sglen)
1053		goto err_rx_sgmap;
1054
1055	tx_sglen = dma_map_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1056			   pl022->sgt_tx.nents, DMA_TO_DEVICE);
1057	if (!tx_sglen)
1058		goto err_tx_sgmap;
1059
1060	/* Send both scatterlists */
1061	rxdesc = dmaengine_prep_slave_sg(rxchan,
1062				      pl022->sgt_rx.sgl,
1063				      rx_sglen,
1064				      DMA_DEV_TO_MEM,
1065				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1066	if (!rxdesc)
1067		goto err_rxdesc;
1068
1069	txdesc = dmaengine_prep_slave_sg(txchan,
1070				      pl022->sgt_tx.sgl,
1071				      tx_sglen,
1072				      DMA_MEM_TO_DEV,
1073				      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
1074	if (!txdesc)
1075		goto err_txdesc;
1076
1077	/* Put the callback on the RX transfer only, that should finish last */
1078	rxdesc->callback = dma_callback;
1079	rxdesc->callback_param = pl022;
1080
1081	/* Submit and fire RX and TX with TX last so we're ready to read! */
1082	dmaengine_submit(rxdesc);
1083	dmaengine_submit(txdesc);
1084	dma_async_issue_pending(rxchan);
1085	dma_async_issue_pending(txchan);
1086	pl022->dma_running = true;
1087
1088	return 0;
1089
1090err_txdesc:
1091	dmaengine_terminate_all(txchan);
1092err_rxdesc:
1093	dmaengine_terminate_all(rxchan);
1094	dma_unmap_sg(txchan->device->dev, pl022->sgt_tx.sgl,
1095		     pl022->sgt_tx.nents, DMA_TO_DEVICE);
1096err_tx_sgmap:
1097	dma_unmap_sg(rxchan->device->dev, pl022->sgt_rx.sgl,
1098		     pl022->sgt_rx.nents, DMA_FROM_DEVICE);
1099err_rx_sgmap:
1100	sg_free_table(&pl022->sgt_tx);
1101err_alloc_tx_sg:
1102	sg_free_table(&pl022->sgt_rx);
1103err_alloc_rx_sg:
1104	return -ENOMEM;
1105}
1106
1107static int pl022_dma_probe(struct pl022 *pl022)
1108{
1109	dma_cap_mask_t mask;
1110
1111	/* Try to acquire a generic DMA engine slave channel */
1112	dma_cap_zero(mask);
1113	dma_cap_set(DMA_SLAVE, mask);
1114	/*
1115	 * We need both RX and TX channels to do DMA, else do none
1116	 * of them.
1117	 */
1118	pl022->dma_rx_channel = dma_request_channel(mask,
1119					    pl022->master_info->dma_filter,
1120					    pl022->master_info->dma_rx_param);
1121	if (!pl022->dma_rx_channel) {
1122		dev_dbg(&pl022->adev->dev, "no RX DMA channel!\n");
1123		goto err_no_rxchan;
1124	}
1125
1126	pl022->dma_tx_channel = dma_request_channel(mask,
1127					    pl022->master_info->dma_filter,
1128					    pl022->master_info->dma_tx_param);
1129	if (!pl022->dma_tx_channel) {
1130		dev_dbg(&pl022->adev->dev, "no TX DMA channel!\n");
1131		goto err_no_txchan;
1132	}
1133
1134	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1135	if (!pl022->dummypage)
1136		goto err_no_dummypage;
1137
1138	dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
1139		 dma_chan_name(pl022->dma_rx_channel),
1140		 dma_chan_name(pl022->dma_tx_channel));
1141
1142	return 0;
1143
1144err_no_dummypage:
1145	dma_release_channel(pl022->dma_tx_channel);
1146err_no_txchan:
1147	dma_release_channel(pl022->dma_rx_channel);
1148	pl022->dma_rx_channel = NULL;
1149err_no_rxchan:
1150	dev_err(&pl022->adev->dev,
1151			"Failed to work in dma mode, work without dma!\n");
1152	return -ENODEV;
1153}
1154
1155static int pl022_dma_autoprobe(struct pl022 *pl022)
1156{
1157	struct device *dev = &pl022->adev->dev;
1158	struct dma_chan *chan;
1159	int err;
1160
1161	/* automatically configure DMA channels from platform, normally using DT */
1162	chan = dma_request_slave_channel_reason(dev, "rx");
1163	if (IS_ERR(chan)) {
1164		err = PTR_ERR(chan);
1165		goto err_no_rxchan;
1166	}
1167
1168	pl022->dma_rx_channel = chan;
1169
1170	chan = dma_request_slave_channel_reason(dev, "tx");
1171	if (IS_ERR(chan)) {
1172		err = PTR_ERR(chan);
1173		goto err_no_txchan;
1174	}
1175
1176	pl022->dma_tx_channel = chan;
1177
1178	pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
1179	if (!pl022->dummypage) {
1180		err = -ENOMEM;
1181		goto err_no_dummypage;
1182	}
1183
1184	return 0;
1185
1186err_no_dummypage:
1187	dma_release_channel(pl022->dma_tx_channel);
1188	pl022->dma_tx_channel = NULL;
1189err_no_txchan:
1190	dma_release_channel(pl022->dma_rx_channel);
1191	pl022->dma_rx_channel = NULL;
1192err_no_rxchan:
1193	return err;
1194}
1195		
1196static void terminate_dma(struct pl022 *pl022)
1197{
1198	struct dma_chan *rxchan = pl022->dma_rx_channel;
1199	struct dma_chan *txchan = pl022->dma_tx_channel;
1200
1201	dmaengine_terminate_all(rxchan);
1202	dmaengine_terminate_all(txchan);
1203	unmap_free_dma_scatter(pl022);
1204	pl022->dma_running = false;
1205}
1206
1207static void pl022_dma_remove(struct pl022 *pl022)
1208{
1209	if (pl022->dma_running)
1210		terminate_dma(pl022);
1211	if (pl022->dma_tx_channel)
1212		dma_release_channel(pl022->dma_tx_channel);
1213	if (pl022->dma_rx_channel)
1214		dma_release_channel(pl022->dma_rx_channel);
1215	kfree(pl022->dummypage);
1216}
1217
1218#else
1219static inline int configure_dma(struct pl022 *pl022)
1220{
1221	return -ENODEV;
1222}
1223
1224static inline int pl022_dma_autoprobe(struct pl022 *pl022)
1225{
1226	return 0;
1227}
1228
1229static inline int pl022_dma_probe(struct pl022 *pl022)
1230{
1231	return 0;
1232}
1233
1234static inline void pl022_dma_remove(struct pl022 *pl022)
1235{
1236}
1237#endif
1238
1239/**
1240 * pl022_interrupt_handler - Interrupt handler for SSP controller
1241 *
1242 * This function handles interrupts generated for an interrupt based transfer.
1243 * If a receive overrun (ROR) interrupt is there then we disable SSP, flag the
1244 * current message's state as STATE_ERROR and schedule the tasklet
1245 * pump_transfers which will do the postprocessing of the current message by
1246 * calling giveback(). Otherwise it reads data from RX FIFO till there is no
1247 * more data, and writes data in TX FIFO till it is not full. If we complete
1248 * the transfer we move to the next transfer and schedule the tasklet.
1249 */
1250static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
1251{
1252	struct pl022 *pl022 = dev_id;
1253	struct spi_message *msg = pl022->cur_msg;
1254	u16 irq_status = 0;
1255
1256	if (unlikely(!msg)) {
1257		dev_err(&pl022->adev->dev,
1258			"bad message state in interrupt handler");
1259		/* Never fail */
1260		return IRQ_HANDLED;
1261	}
1262
1263	/* Read the Interrupt Status Register */
1264	irq_status = readw(SSP_MIS(pl022->virtbase));
1265
1266	if (unlikely(!irq_status))
1267		return IRQ_NONE;
1268
1269	/*
1270	 * This handles the FIFO interrupts, the timeout
1271	 * interrupts are flatly ignored, they cannot be
1272	 * trusted.
1273	 */
1274	if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
1275		/*
1276		 * Overrun interrupt - bail out since our Data has been
1277		 * corrupted
1278		 */
1279		dev_err(&pl022->adev->dev, "FIFO overrun\n");
1280		if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
1281			dev_err(&pl022->adev->dev,
1282				"RXFIFO is full\n");
1283
1284		/*
1285		 * Disable and clear interrupts, disable SSP,
1286		 * mark message with bad status so it can be
1287		 * retried.
1288		 */
1289		writew(DISABLE_ALL_INTERRUPTS,
1290		       SSP_IMSC(pl022->virtbase));
1291		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1292		writew((readw(SSP_CR1(pl022->virtbase)) &
1293			(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1294		msg->state = STATE_ERROR;
1295
1296		/* Schedule message queue handler */
1297		tasklet_schedule(&pl022->pump_transfers);
1298		return IRQ_HANDLED;
1299	}
1300
1301	readwriter(pl022);
1302
1303	if (pl022->tx == pl022->tx_end) {
1304		/* Disable Transmit interrupt, enable receive interrupt */
1305		writew((readw(SSP_IMSC(pl022->virtbase)) &
1306		       ~SSP_IMSC_MASK_TXIM) | SSP_IMSC_MASK_RXIM,
1307		       SSP_IMSC(pl022->virtbase));
1308	}
1309
1310	/*
1311	 * Since all transactions must write as much as shall be read,
1312	 * we can conclude the entire transaction once RX is complete.
1313	 * At this point, all TX will always be finished.
1314	 */
1315	if (pl022->rx >= pl022->rx_end) {
1316		writew(DISABLE_ALL_INTERRUPTS,
1317		       SSP_IMSC(pl022->virtbase));
1318		writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
1319		if (unlikely(pl022->rx > pl022->rx_end)) {
1320			dev_warn(&pl022->adev->dev, "read %u surplus "
1321				 "bytes (did you request an odd "
1322				 "number of bytes on a 16bit bus?)\n",
1323				 (u32) (pl022->rx - pl022->rx_end));
1324		}
1325		/* Update total bytes transferred */
1326		msg->actual_length += pl022->cur_transfer->len;
 
 
1327		/* Move to next transfer */
1328		msg->state = next_transfer(pl022);
1329		if (msg->state != STATE_DONE && pl022->cur_transfer->cs_change)
1330			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1331		tasklet_schedule(&pl022->pump_transfers);
1332		return IRQ_HANDLED;
1333	}
1334
1335	return IRQ_HANDLED;
1336}
1337
1338/**
1339 * This sets up the pointers to memory for the next message to
1340 * send out on the SPI bus.
1341 */
1342static int set_up_next_transfer(struct pl022 *pl022,
1343				struct spi_transfer *transfer)
1344{
1345	int residue;
1346
1347	/* Sanity check the message for this bus width */
1348	residue = pl022->cur_transfer->len % pl022->cur_chip->n_bytes;
1349	if (unlikely(residue != 0)) {
1350		dev_err(&pl022->adev->dev,
1351			"message of %u bytes to transmit but the current "
1352			"chip bus has a data width of %u bytes!\n",
1353			pl022->cur_transfer->len,
1354			pl022->cur_chip->n_bytes);
1355		dev_err(&pl022->adev->dev, "skipping this message\n");
1356		return -EIO;
1357	}
1358	pl022->tx = (void *)transfer->tx_buf;
1359	pl022->tx_end = pl022->tx + pl022->cur_transfer->len;
1360	pl022->rx = (void *)transfer->rx_buf;
1361	pl022->rx_end = pl022->rx + pl022->cur_transfer->len;
1362	pl022->write =
1363	    pl022->tx ? pl022->cur_chip->write : WRITING_NULL;
1364	pl022->read = pl022->rx ? pl022->cur_chip->read : READING_NULL;
1365	return 0;
1366}
1367
1368/**
1369 * pump_transfers - Tasklet function which schedules next transfer
1370 * when running in interrupt or DMA transfer mode.
1371 * @data: SSP driver private data structure
1372 *
1373 */
1374static void pump_transfers(unsigned long data)
1375{
1376	struct pl022 *pl022 = (struct pl022 *) data;
1377	struct spi_message *message = NULL;
1378	struct spi_transfer *transfer = NULL;
1379	struct spi_transfer *previous = NULL;
1380
1381	/* Get current state information */
1382	message = pl022->cur_msg;
1383	transfer = pl022->cur_transfer;
1384
1385	/* Handle for abort */
1386	if (message->state == STATE_ERROR) {
1387		message->status = -EIO;
1388		giveback(pl022);
1389		return;
1390	}
1391
1392	/* Handle end of message */
1393	if (message->state == STATE_DONE) {
1394		message->status = 0;
1395		giveback(pl022);
1396		return;
1397	}
1398
1399	/* Delay if requested at end of transfer before CS change */
1400	if (message->state == STATE_RUNNING) {
1401		previous = list_entry(transfer->transfer_list.prev,
1402					struct spi_transfer,
1403					transfer_list);
1404		if (previous->delay_usecs)
1405			/*
1406			 * FIXME: This runs in interrupt context.
1407			 * Is this really smart?
1408			 */
1409			udelay(previous->delay_usecs);
1410
1411		/* Reselect chip select only if cs_change was requested */
1412		if (previous->cs_change)
1413			pl022_cs_control(pl022, SSP_CHIP_SELECT);
1414	} else {
1415		/* STATE_START */
1416		message->state = STATE_RUNNING;
1417	}
1418
1419	if (set_up_next_transfer(pl022, transfer)) {
1420		message->state = STATE_ERROR;
1421		message->status = -EIO;
1422		giveback(pl022);
1423		return;
1424	}
1425	/* Flush the FIFOs and let's go! */
1426	flush(pl022);
1427
1428	if (pl022->cur_chip->enable_dma) {
1429		if (configure_dma(pl022)) {
1430			dev_dbg(&pl022->adev->dev,
1431				"configuration of DMA failed, fall back to interrupt mode\n");
1432			goto err_config_dma;
1433		}
1434		return;
1435	}
1436
1437err_config_dma:
1438	/* enable all interrupts except RX */
1439	writew(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM, SSP_IMSC(pl022->virtbase));
1440}
1441
1442static void do_interrupt_dma_transfer(struct pl022 *pl022)
1443{
1444	/*
1445	 * Default is to enable all interrupts except RX -
1446	 * this will be enabled once TX is complete
1447	 */
1448	u32 irqflags = (u32)(ENABLE_ALL_INTERRUPTS & ~SSP_IMSC_MASK_RXIM);
1449
1450	/* Enable target chip, if not already active */
1451	if (!pl022->next_msg_cs_active)
1452		pl022_cs_control(pl022, SSP_CHIP_SELECT);
1453
1454	if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
1455		/* Error path */
1456		pl022->cur_msg->state = STATE_ERROR;
1457		pl022->cur_msg->status = -EIO;
1458		giveback(pl022);
1459		return;
1460	}
1461	/* If we're using DMA, set up DMA here */
1462	if (pl022->cur_chip->enable_dma) {
1463		/* Configure DMA transfer */
1464		if (configure_dma(pl022)) {
1465			dev_dbg(&pl022->adev->dev,
1466				"configuration of DMA failed, fall back to interrupt mode\n");
1467			goto err_config_dma;
1468		}
1469		/* Disable interrupts in DMA mode, IRQ from DMA controller */
1470		irqflags = DISABLE_ALL_INTERRUPTS;
1471	}
1472err_config_dma:
1473	/* Enable SSP, turn on interrupts */
1474	writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1475	       SSP_CR1(pl022->virtbase));
1476	writew(irqflags, SSP_IMSC(pl022->virtbase));
1477}
1478
1479static void print_current_status(struct pl022 *pl022)
1480{
1481	u32 read_cr0;
1482	u16 read_cr1, read_dmacr, read_sr;
1483
1484	if (pl022->vendor->extended_cr)
1485		read_cr0 = readl(SSP_CR0(pl022->virtbase));
1486	else
1487		read_cr0 = readw(SSP_CR0(pl022->virtbase));
1488	read_cr1 = readw(SSP_CR1(pl022->virtbase));
1489	read_dmacr = readw(SSP_DMACR(pl022->virtbase));
1490	read_sr = readw(SSP_SR(pl022->virtbase));
1491
1492	dev_warn(&pl022->adev->dev, "spi-pl022 CR0: %x\n", read_cr0);
1493	dev_warn(&pl022->adev->dev, "spi-pl022 CR1: %x\n", read_cr1);
1494	dev_warn(&pl022->adev->dev, "spi-pl022 DMACR: %x\n", read_dmacr);
1495	dev_warn(&pl022->adev->dev, "spi-pl022 SR: %x\n", read_sr);
1496	dev_warn(&pl022->adev->dev,
1497			"spi-pl022 exp_fifo_level/fifodepth: %u/%d\n",
1498			pl022->exp_fifo_level,
1499			pl022->vendor->fifodepth);
1500
1501}
1502
1503static void do_polling_transfer(struct pl022 *pl022)
1504{
1505	struct spi_message *message = NULL;
1506	struct spi_transfer *transfer = NULL;
1507	struct spi_transfer *previous = NULL;
 
1508	unsigned long time, timeout;
1509
 
1510	message = pl022->cur_msg;
1511
1512	while (message->state != STATE_DONE) {
1513		/* Handle for abort */
1514		if (message->state == STATE_ERROR)
1515			break;
1516		transfer = pl022->cur_transfer;
1517
1518		/* Delay if requested at end of transfer */
1519		if (message->state == STATE_RUNNING) {
1520			previous =
1521			    list_entry(transfer->transfer_list.prev,
1522				       struct spi_transfer, transfer_list);
1523			if (previous->delay_usecs)
1524				udelay(previous->delay_usecs);
1525			if (previous->cs_change)
1526				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1527		} else {
1528			/* STATE_START */
1529			message->state = STATE_RUNNING;
1530			if (!pl022->next_msg_cs_active)
1531				pl022_cs_control(pl022, SSP_CHIP_SELECT);
1532		}
1533
1534		/* Configuration Changing Per Transfer */
1535		if (set_up_next_transfer(pl022, transfer)) {
1536			/* Error path */
1537			message->state = STATE_ERROR;
1538			break;
1539		}
1540		/* Flush FIFOs and enable SSP */
1541		flush(pl022);
1542		writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
1543		       SSP_CR1(pl022->virtbase));
1544
1545		dev_dbg(&pl022->adev->dev, "polling transfer ongoing ...\n");
1546
1547		timeout = jiffies + msecs_to_jiffies(SPI_POLLING_TIMEOUT);
1548		while (pl022->tx < pl022->tx_end || pl022->rx < pl022->rx_end) {
1549			time = jiffies;
1550			readwriter(pl022);
1551			if (time_after(time, timeout)) {
1552				dev_warn(&pl022->adev->dev,
1553				"%s: timeout!\n", __func__);
1554				message->state = STATE_TIMEOUT;
1555				print_current_status(pl022);
1556				goto out;
1557			}
1558			cpu_relax();
1559		}
1560
1561		/* Update total byte transferred */
1562		message->actual_length += pl022->cur_transfer->len;
 
 
1563		/* Move to next transfer */
1564		message->state = next_transfer(pl022);
1565		if (message->state != STATE_DONE
1566		    && pl022->cur_transfer->cs_change)
1567			pl022_cs_control(pl022, SSP_CHIP_DESELECT);
1568	}
1569out:
1570	/* Handle end of message */
1571	if (message->state == STATE_DONE)
1572		message->status = 0;
1573	else if (message->state == STATE_TIMEOUT)
1574		message->status = -EAGAIN;
1575	else
1576		message->status = -EIO;
1577
1578	giveback(pl022);
1579	return;
1580}
1581
1582static int pl022_transfer_one_message(struct spi_master *master,
1583				      struct spi_message *msg)
1584{
1585	struct pl022 *pl022 = spi_master_get_devdata(master);
1586
1587	/* Initial message state */
1588	pl022->cur_msg = msg;
1589	msg->state = STATE_START;
1590
1591	pl022->cur_transfer = list_entry(msg->transfers.next,
1592					 struct spi_transfer, transfer_list);
1593
1594	/* Setup the SPI using the per chip configuration */
1595	pl022->cur_chip = spi_get_ctldata(msg->spi);
1596	pl022->cur_cs = pl022->chipselects[msg->spi->chip_select];
1597
1598	restore_state(pl022);
1599	flush(pl022);
1600
1601	if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
1602		do_polling_transfer(pl022);
1603	else
1604		do_interrupt_dma_transfer(pl022);
1605
1606	return 0;
1607}
1608
1609static int pl022_unprepare_transfer_hardware(struct spi_master *master)
1610{
1611	struct pl022 *pl022 = spi_master_get_devdata(master);
1612
1613	/* nothing more to do - disable spi/ssp and power off */
1614	writew((readw(SSP_CR1(pl022->virtbase)) &
1615		(~SSP_CR1_MASK_SSE)), SSP_CR1(pl022->virtbase));
1616
1617	return 0;
1618}
1619
1620static int verify_controller_parameters(struct pl022 *pl022,
1621				struct pl022_config_chip const *chip_info)
1622{
1623	if ((chip_info->iface < SSP_INTERFACE_MOTOROLA_SPI)
1624	    || (chip_info->iface > SSP_INTERFACE_UNIDIRECTIONAL)) {
1625		dev_err(&pl022->adev->dev,
1626			"interface is configured incorrectly\n");
1627		return -EINVAL;
1628	}
1629	if ((chip_info->iface == SSP_INTERFACE_UNIDIRECTIONAL) &&
1630	    (!pl022->vendor->unidir)) {
1631		dev_err(&pl022->adev->dev,
1632			"unidirectional mode not supported in this "
1633			"hardware version\n");
1634		return -EINVAL;
1635	}
1636	if ((chip_info->hierarchy != SSP_MASTER)
1637	    && (chip_info->hierarchy != SSP_SLAVE)) {
1638		dev_err(&pl022->adev->dev,
1639			"hierarchy is configured incorrectly\n");
1640		return -EINVAL;
1641	}
1642	if ((chip_info->com_mode != INTERRUPT_TRANSFER)
1643	    && (chip_info->com_mode != DMA_TRANSFER)
1644	    && (chip_info->com_mode != POLLING_TRANSFER)) {
1645		dev_err(&pl022->adev->dev,
1646			"Communication mode is configured incorrectly\n");
1647		return -EINVAL;
1648	}
1649	switch (chip_info->rx_lev_trig) {
1650	case SSP_RX_1_OR_MORE_ELEM:
1651	case SSP_RX_4_OR_MORE_ELEM:
1652	case SSP_RX_8_OR_MORE_ELEM:
1653		/* These are always OK, all variants can handle this */
1654		break;
1655	case SSP_RX_16_OR_MORE_ELEM:
1656		if (pl022->vendor->fifodepth < 16) {
1657			dev_err(&pl022->adev->dev,
1658			"RX FIFO Trigger Level is configured incorrectly\n");
1659			return -EINVAL;
1660		}
1661		break;
1662	case SSP_RX_32_OR_MORE_ELEM:
1663		if (pl022->vendor->fifodepth < 32) {
1664			dev_err(&pl022->adev->dev,
1665			"RX FIFO Trigger Level is configured incorrectly\n");
1666			return -EINVAL;
1667		}
1668		break;
1669	default:
1670		dev_err(&pl022->adev->dev,
1671			"RX FIFO Trigger Level is configured incorrectly\n");
1672		return -EINVAL;
1673	}
1674	switch (chip_info->tx_lev_trig) {
1675	case SSP_TX_1_OR_MORE_EMPTY_LOC:
1676	case SSP_TX_4_OR_MORE_EMPTY_LOC:
1677	case SSP_TX_8_OR_MORE_EMPTY_LOC:
1678		/* These are always OK, all variants can handle this */
1679		break;
1680	case SSP_TX_16_OR_MORE_EMPTY_LOC:
1681		if (pl022->vendor->fifodepth < 16) {
1682			dev_err(&pl022->adev->dev,
1683			"TX FIFO Trigger Level is configured incorrectly\n");
1684			return -EINVAL;
1685		}
1686		break;
1687	case SSP_TX_32_OR_MORE_EMPTY_LOC:
1688		if (pl022->vendor->fifodepth < 32) {
1689			dev_err(&pl022->adev->dev,
1690			"TX FIFO Trigger Level is configured incorrectly\n");
1691			return -EINVAL;
1692		}
1693		break;
1694	default:
1695		dev_err(&pl022->adev->dev,
1696			"TX FIFO Trigger Level is configured incorrectly\n");
1697		return -EINVAL;
1698	}
1699	if (chip_info->iface == SSP_INTERFACE_NATIONAL_MICROWIRE) {
1700		if ((chip_info->ctrl_len < SSP_BITS_4)
1701		    || (chip_info->ctrl_len > SSP_BITS_32)) {
1702			dev_err(&pl022->adev->dev,
1703				"CTRL LEN is configured incorrectly\n");
1704			return -EINVAL;
1705		}
1706		if ((chip_info->wait_state != SSP_MWIRE_WAIT_ZERO)
1707		    && (chip_info->wait_state != SSP_MWIRE_WAIT_ONE)) {
1708			dev_err(&pl022->adev->dev,
1709				"Wait State is configured incorrectly\n");
1710			return -EINVAL;
1711		}
1712		/* Half duplex is only available in the ST Micro version */
1713		if (pl022->vendor->extended_cr) {
1714			if ((chip_info->duplex !=
1715			     SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1716			    && (chip_info->duplex !=
1717				SSP_MICROWIRE_CHANNEL_HALF_DUPLEX)) {
1718				dev_err(&pl022->adev->dev,
1719					"Microwire duplex mode is configured incorrectly\n");
1720				return -EINVAL;
1721			}
1722		} else {
1723			if (chip_info->duplex != SSP_MICROWIRE_CHANNEL_FULL_DUPLEX)
1724				dev_err(&pl022->adev->dev,
1725					"Microwire half duplex mode requested,"
1726					" but this is only available in the"
1727					" ST version of PL022\n");
1728			return -EINVAL;
1729		}
1730	}
1731	return 0;
1732}
1733
1734static inline u32 spi_rate(u32 rate, u16 cpsdvsr, u16 scr)
1735{
1736	return rate / (cpsdvsr * (1 + scr));
1737}
1738
1739static int calculate_effective_freq(struct pl022 *pl022, int freq, struct
1740				    ssp_clock_params * clk_freq)
1741{
1742	/* Lets calculate the frequency parameters */
1743	u16 cpsdvsr = CPSDVR_MIN, scr = SCR_MIN;
1744	u32 rate, max_tclk, min_tclk, best_freq = 0, best_cpsdvsr = 0,
1745		best_scr = 0, tmp, found = 0;
1746
1747	rate = clk_get_rate(pl022->clk);
1748	/* cpsdvscr = 2 & scr 0 */
1749	max_tclk = spi_rate(rate, CPSDVR_MIN, SCR_MIN);
1750	/* cpsdvsr = 254 & scr = 255 */
1751	min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX);
1752
1753	if (freq > max_tclk)
1754		dev_warn(&pl022->adev->dev,
1755			"Max speed that can be programmed is %d Hz, you requested %d\n",
1756			max_tclk, freq);
1757
1758	if (freq < min_tclk) {
1759		dev_err(&pl022->adev->dev,
1760			"Requested frequency: %d Hz is less than minimum possible %d Hz\n",
1761			freq, min_tclk);
1762		return -EINVAL;
1763	}
1764
1765	/*
1766	 * best_freq will give closest possible available rate (<= requested
1767	 * freq) for all values of scr & cpsdvsr.
1768	 */
1769	while ((cpsdvsr <= CPSDVR_MAX) && !found) {
1770		while (scr <= SCR_MAX) {
1771			tmp = spi_rate(rate, cpsdvsr, scr);
1772
1773			if (tmp > freq) {
1774				/* we need lower freq */
1775				scr++;
1776				continue;
1777			}
1778
1779			/*
1780			 * If found exact value, mark found and break.
1781			 * If found more closer value, update and break.
1782			 */
1783			if (tmp > best_freq) {
1784				best_freq = tmp;
1785				best_cpsdvsr = cpsdvsr;
1786				best_scr = scr;
1787
1788				if (tmp == freq)
1789					found = 1;
1790			}
1791			/*
1792			 * increased scr will give lower rates, which are not
1793			 * required
1794			 */
1795			break;
1796		}
1797		cpsdvsr += 2;
1798		scr = SCR_MIN;
1799	}
1800
1801	WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n",
1802			freq);
1803
1804	clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF);
1805	clk_freq->scr = (u8) (best_scr & 0xFF);
1806	dev_dbg(&pl022->adev->dev,
1807		"SSP Target Frequency is: %u, Effective Frequency is %u\n",
1808		freq, best_freq);
1809	dev_dbg(&pl022->adev->dev, "SSP cpsdvsr = %d, scr = %d\n",
1810		clk_freq->cpsdvsr, clk_freq->scr);
1811
1812	return 0;
1813}
1814
1815/*
1816 * A piece of default chip info unless the platform
1817 * supplies it.
1818 */
1819static const struct pl022_config_chip pl022_default_chip_info = {
1820	.com_mode = POLLING_TRANSFER,
1821	.iface = SSP_INTERFACE_MOTOROLA_SPI,
1822	.hierarchy = SSP_SLAVE,
1823	.slave_tx_disable = DO_NOT_DRIVE_TX,
1824	.rx_lev_trig = SSP_RX_1_OR_MORE_ELEM,
1825	.tx_lev_trig = SSP_TX_1_OR_MORE_EMPTY_LOC,
1826	.ctrl_len = SSP_BITS_8,
1827	.wait_state = SSP_MWIRE_WAIT_ZERO,
1828	.duplex = SSP_MICROWIRE_CHANNEL_FULL_DUPLEX,
1829	.cs_control = null_cs_control,
1830};
1831
1832/**
1833 * pl022_setup - setup function registered to SPI master framework
1834 * @spi: spi device which is requesting setup
1835 *
1836 * This function is registered to the SPI framework for this SPI master
1837 * controller. If it is the first time when setup is called by this device,
1838 * this function will initialize the runtime state for this chip and save
1839 * the same in the device structure. Else it will update the runtime info
1840 * with the updated chip info. Nothing is really being written to the
1841 * controller hardware here, that is not done until the actual transfer
1842 * commence.
1843 */
1844static int pl022_setup(struct spi_device *spi)
1845{
1846	struct pl022_config_chip const *chip_info;
1847	struct pl022_config_chip chip_info_dt;
1848	struct chip_data *chip;
1849	struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0};
1850	int status = 0;
1851	struct pl022 *pl022 = spi_master_get_devdata(spi->master);
1852	unsigned int bits = spi->bits_per_word;
1853	u32 tmp;
1854	struct device_node *np = spi->dev.of_node;
1855
1856	if (!spi->max_speed_hz)
1857		return -EINVAL;
1858
1859	/* Get controller_state if one is supplied */
1860	chip = spi_get_ctldata(spi);
1861
1862	if (chip == NULL) {
1863		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
1864		if (!chip)
1865			return -ENOMEM;
1866		dev_dbg(&spi->dev,
1867			"allocated memory for controller's runtime state\n");
1868	}
1869
1870	/* Get controller data if one is supplied */
1871	chip_info = spi->controller_data;
1872
1873	if (chip_info == NULL) {
1874		if (np) {
1875			chip_info_dt = pl022_default_chip_info;
1876
1877			chip_info_dt.hierarchy = SSP_MASTER;
1878			of_property_read_u32(np, "pl022,interface",
1879				&chip_info_dt.iface);
1880			of_property_read_u32(np, "pl022,com-mode",
1881				&chip_info_dt.com_mode);
1882			of_property_read_u32(np, "pl022,rx-level-trig",
1883				&chip_info_dt.rx_lev_trig);
1884			of_property_read_u32(np, "pl022,tx-level-trig",
1885				&chip_info_dt.tx_lev_trig);
1886			of_property_read_u32(np, "pl022,ctrl-len",
1887				&chip_info_dt.ctrl_len);
1888			of_property_read_u32(np, "pl022,wait-state",
1889				&chip_info_dt.wait_state);
1890			of_property_read_u32(np, "pl022,duplex",
1891				&chip_info_dt.duplex);
1892
1893			chip_info = &chip_info_dt;
1894		} else {
1895			chip_info = &pl022_default_chip_info;
1896			/* spi_board_info.controller_data not is supplied */
1897			dev_dbg(&spi->dev,
1898				"using default controller_data settings\n");
1899		}
1900	} else
1901		dev_dbg(&spi->dev,
1902			"using user supplied controller_data settings\n");
1903
1904	/*
1905	 * We can override with custom divisors, else we use the board
1906	 * frequency setting
1907	 */
1908	if ((0 == chip_info->clk_freq.cpsdvsr)
1909	    && (0 == chip_info->clk_freq.scr)) {
1910		status = calculate_effective_freq(pl022,
1911						  spi->max_speed_hz,
1912						  &clk_freq);
1913		if (status < 0)
1914			goto err_config_params;
1915	} else {
1916		memcpy(&clk_freq, &chip_info->clk_freq, sizeof(clk_freq));
1917		if ((clk_freq.cpsdvsr % 2) != 0)
1918			clk_freq.cpsdvsr =
1919				clk_freq.cpsdvsr - 1;
1920	}
1921	if ((clk_freq.cpsdvsr < CPSDVR_MIN)
1922	    || (clk_freq.cpsdvsr > CPSDVR_MAX)) {
1923		status = -EINVAL;
1924		dev_err(&spi->dev,
1925			"cpsdvsr is configured incorrectly\n");
1926		goto err_config_params;
1927	}
1928
1929	status = verify_controller_parameters(pl022, chip_info);
1930	if (status) {
1931		dev_err(&spi->dev, "controller data is incorrect");
1932		goto err_config_params;
1933	}
1934
1935	pl022->rx_lev_trig = chip_info->rx_lev_trig;
1936	pl022->tx_lev_trig = chip_info->tx_lev_trig;
1937
1938	/* Now set controller state based on controller data */
1939	chip->xfer_type = chip_info->com_mode;
1940	if (!chip_info->cs_control) {
1941		chip->cs_control = null_cs_control;
1942		if (!gpio_is_valid(pl022->chipselects[spi->chip_select]))
1943			dev_warn(&spi->dev,
1944				 "invalid chip select\n");
1945	} else
1946		chip->cs_control = chip_info->cs_control;
1947
1948	/* Check bits per word with vendor specific range */
1949	if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) {
1950		status = -ENOTSUPP;
1951		dev_err(&spi->dev, "illegal data size for this controller!\n");
1952		dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n",
1953				pl022->vendor->max_bpw);
1954		goto err_config_params;
1955	} else if (bits <= 8) {
1956		dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n");
1957		chip->n_bytes = 1;
1958		chip->read = READING_U8;
1959		chip->write = WRITING_U8;
1960	} else if (bits <= 16) {
1961		dev_dbg(&spi->dev, "9 <= n <= 16 bits per word\n");
1962		chip->n_bytes = 2;
1963		chip->read = READING_U16;
1964		chip->write = WRITING_U16;
1965	} else {
1966		dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n");
1967		chip->n_bytes = 4;
1968		chip->read = READING_U32;
1969		chip->write = WRITING_U32;
1970	}
1971
1972	/* Now Initialize all register settings required for this chip */
1973	chip->cr0 = 0;
1974	chip->cr1 = 0;
1975	chip->dmacr = 0;
1976	chip->cpsr = 0;
1977	if ((chip_info->com_mode == DMA_TRANSFER)
1978	    && ((pl022->master_info)->enable_dma)) {
1979		chip->enable_dma = true;
1980		dev_dbg(&spi->dev, "DMA mode set in controller state\n");
1981		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1982			       SSP_DMACR_MASK_RXDMAE, 0);
1983		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
1984			       SSP_DMACR_MASK_TXDMAE, 1);
1985	} else {
1986		chip->enable_dma = false;
1987		dev_dbg(&spi->dev, "DMA mode NOT set in controller state\n");
1988		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1989			       SSP_DMACR_MASK_RXDMAE, 0);
1990		SSP_WRITE_BITS(chip->dmacr, SSP_DMA_DISABLED,
1991			       SSP_DMACR_MASK_TXDMAE, 1);
1992	}
1993
1994	chip->cpsr = clk_freq.cpsdvsr;
1995
1996	/* Special setup for the ST micro extended control registers */
1997	if (pl022->vendor->extended_cr) {
1998		u32 etx;
1999
2000		if (pl022->vendor->pl023) {
2001			/* These bits are only in the PL023 */
2002			SSP_WRITE_BITS(chip->cr1, chip_info->clkdelay,
2003				       SSP_CR1_MASK_FBCLKDEL_ST, 13);
2004		} else {
2005			/* These bits are in the PL022 but not PL023 */
2006			SSP_WRITE_BITS(chip->cr0, chip_info->duplex,
2007				       SSP_CR0_MASK_HALFDUP_ST, 5);
2008			SSP_WRITE_BITS(chip->cr0, chip_info->ctrl_len,
2009				       SSP_CR0_MASK_CSS_ST, 16);
2010			SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2011				       SSP_CR0_MASK_FRF_ST, 21);
2012			SSP_WRITE_BITS(chip->cr1, chip_info->wait_state,
2013				       SSP_CR1_MASK_MWAIT_ST, 6);
2014		}
2015		SSP_WRITE_BITS(chip->cr0, bits - 1,
2016			       SSP_CR0_MASK_DSS_ST, 0);
2017
2018		if (spi->mode & SPI_LSB_FIRST) {
2019			tmp = SSP_RX_LSB;
2020			etx = SSP_TX_LSB;
2021		} else {
2022			tmp = SSP_RX_MSB;
2023			etx = SSP_TX_MSB;
2024		}
2025		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_RENDN_ST, 4);
2026		SSP_WRITE_BITS(chip->cr1, etx, SSP_CR1_MASK_TENDN_ST, 5);
2027		SSP_WRITE_BITS(chip->cr1, chip_info->rx_lev_trig,
2028			       SSP_CR1_MASK_RXIFLSEL_ST, 7);
2029		SSP_WRITE_BITS(chip->cr1, chip_info->tx_lev_trig,
2030			       SSP_CR1_MASK_TXIFLSEL_ST, 10);
2031	} else {
2032		SSP_WRITE_BITS(chip->cr0, bits - 1,
2033			       SSP_CR0_MASK_DSS, 0);
2034		SSP_WRITE_BITS(chip->cr0, chip_info->iface,
2035			       SSP_CR0_MASK_FRF, 4);
2036	}
2037
2038	/* Stuff that is common for all versions */
2039	if (spi->mode & SPI_CPOL)
2040		tmp = SSP_CLK_POL_IDLE_HIGH;
2041	else
2042		tmp = SSP_CLK_POL_IDLE_LOW;
2043	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPO, 6);
2044
2045	if (spi->mode & SPI_CPHA)
2046		tmp = SSP_CLK_SECOND_EDGE;
2047	else
2048		tmp = SSP_CLK_FIRST_EDGE;
2049	SSP_WRITE_BITS(chip->cr0, tmp, SSP_CR0_MASK_SPH, 7);
2050
2051	SSP_WRITE_BITS(chip->cr0, clk_freq.scr, SSP_CR0_MASK_SCR, 8);
2052	/* Loopback is available on all versions except PL023 */
2053	if (pl022->vendor->loopback) {
2054		if (spi->mode & SPI_LOOP)
2055			tmp = LOOPBACK_ENABLED;
2056		else
2057			tmp = LOOPBACK_DISABLED;
2058		SSP_WRITE_BITS(chip->cr1, tmp, SSP_CR1_MASK_LBM, 0);
2059	}
2060	SSP_WRITE_BITS(chip->cr1, SSP_DISABLED, SSP_CR1_MASK_SSE, 1);
2061	SSP_WRITE_BITS(chip->cr1, chip_info->hierarchy, SSP_CR1_MASK_MS, 2);
2062	SSP_WRITE_BITS(chip->cr1, chip_info->slave_tx_disable, SSP_CR1_MASK_SOD,
2063		3);
2064
2065	/* Save controller_state */
2066	spi_set_ctldata(spi, chip);
2067	return status;
2068 err_config_params:
2069	spi_set_ctldata(spi, NULL);
2070	kfree(chip);
2071	return status;
2072}
2073
2074/**
2075 * pl022_cleanup - cleanup function registered to SPI master framework
2076 * @spi: spi device which is requesting cleanup
2077 *
2078 * This function is registered to the SPI framework for this SPI master
2079 * controller. It will free the runtime state of chip.
2080 */
2081static void pl022_cleanup(struct spi_device *spi)
2082{
2083	struct chip_data *chip = spi_get_ctldata(spi);
2084
2085	spi_set_ctldata(spi, NULL);
2086	kfree(chip);
2087}
2088
2089static struct pl022_ssp_controller *
2090pl022_platform_data_dt_get(struct device *dev)
2091{
2092	struct device_node *np = dev->of_node;
2093	struct pl022_ssp_controller *pd;
2094	u32 tmp = 0;
2095
2096	if (!np) {
2097		dev_err(dev, "no dt node defined\n");
2098		return NULL;
2099	}
2100
2101	pd = devm_kzalloc(dev, sizeof(struct pl022_ssp_controller), GFP_KERNEL);
2102	if (!pd)
2103		return NULL;
2104
2105	pd->bus_id = -1;
2106	pd->enable_dma = 1;
2107	of_property_read_u32(np, "num-cs", &tmp);
2108	pd->num_chipselect = tmp;
2109	of_property_read_u32(np, "pl022,autosuspend-delay",
2110			     &pd->autosuspend_delay);
2111	pd->rt = of_property_read_bool(np, "pl022,rt");
2112
2113	return pd;
2114}
2115
2116static int pl022_probe(struct amba_device *adev, const struct amba_id *id)
2117{
2118	struct device *dev = &adev->dev;
2119	struct pl022_ssp_controller *platform_info =
2120			dev_get_platdata(&adev->dev);
2121	struct spi_master *master;
2122	struct pl022 *pl022 = NULL;	/*Data for this driver */
2123	struct device_node *np = adev->dev.of_node;
2124	int status = 0, i, num_cs;
2125
2126	dev_info(&adev->dev,
2127		 "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid);
2128	if (!platform_info && IS_ENABLED(CONFIG_OF))
2129		platform_info = pl022_platform_data_dt_get(dev);
2130
2131	if (!platform_info) {
2132		dev_err(dev, "probe: no platform data defined\n");
2133		return -ENODEV;
2134	}
2135
2136	if (platform_info->num_chipselect) {
2137		num_cs = platform_info->num_chipselect;
2138	} else {
2139		dev_err(dev, "probe: no chip select defined\n");
2140		return -ENODEV;
2141	}
2142
2143	/* Allocate master with space for data */
2144	master = spi_alloc_master(dev, sizeof(struct pl022));
2145	if (master == NULL) {
2146		dev_err(&adev->dev, "probe - cannot alloc SPI master\n");
2147		return -ENOMEM;
2148	}
2149
2150	pl022 = spi_master_get_devdata(master);
2151	pl022->master = master;
2152	pl022->master_info = platform_info;
2153	pl022->adev = adev;
2154	pl022->vendor = id->data;
2155	pl022->chipselects = devm_kcalloc(dev, num_cs, sizeof(int),
2156					  GFP_KERNEL);
2157	if (!pl022->chipselects) {
2158		status = -ENOMEM;
2159		goto err_no_mem;
2160	}
2161
2162	/*
2163	 * Bus Number Which has been Assigned to this SSP controller
2164	 * on this board
2165	 */
2166	master->bus_num = platform_info->bus_id;
2167	master->num_chipselect = num_cs;
2168	master->cleanup = pl022_cleanup;
2169	master->setup = pl022_setup;
2170	master->auto_runtime_pm = true;
2171	master->transfer_one_message = pl022_transfer_one_message;
2172	master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware;
2173	master->rt = platform_info->rt;
2174	master->dev.of_node = dev->of_node;
2175
2176	if (platform_info->num_chipselect && platform_info->chipselects) {
2177		for (i = 0; i < num_cs; i++)
2178			pl022->chipselects[i] = platform_info->chipselects[i];
2179	} else if (pl022->vendor->internal_cs_ctrl) {
2180		for (i = 0; i < num_cs; i++)
2181			pl022->chipselects[i] = i;
2182	} else if (IS_ENABLED(CONFIG_OF)) {
2183		for (i = 0; i < num_cs; i++) {
2184			int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
2185
2186			if (cs_gpio == -EPROBE_DEFER) {
2187				status = -EPROBE_DEFER;
2188				goto err_no_gpio;
2189			}
2190
2191			pl022->chipselects[i] = cs_gpio;
2192
2193			if (gpio_is_valid(cs_gpio)) {
2194				if (devm_gpio_request(dev, cs_gpio, "ssp-pl022"))
2195					dev_err(&adev->dev,
2196						"could not request %d gpio\n",
2197						cs_gpio);
2198				else if (gpio_direction_output(cs_gpio, 1))
2199					dev_err(&adev->dev,
2200						"could not set gpio %d as output\n",
2201						cs_gpio);
2202			}
2203		}
2204	}
2205
2206	/*
2207	 * Supports mode 0-3, loopback, and active low CS. Transfers are
2208	 * always MS bit first on the original pl022.
2209	 */
2210	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
2211	if (pl022->vendor->extended_cr)
2212		master->mode_bits |= SPI_LSB_FIRST;
2213
2214	dev_dbg(&adev->dev, "BUSNO: %d\n", master->bus_num);
2215
2216	status = amba_request_regions(adev, NULL);
2217	if (status)
2218		goto err_no_ioregion;
2219
2220	pl022->phybase = adev->res.start;
2221	pl022->virtbase = devm_ioremap(dev, adev->res.start,
2222				       resource_size(&adev->res));
2223	if (pl022->virtbase == NULL) {
2224		status = -ENOMEM;
2225		goto err_no_ioremap;
2226	}
2227	dev_info(&adev->dev, "mapped registers from %pa to %p\n",
2228		&adev->res.start, pl022->virtbase);
2229
2230	pl022->clk = devm_clk_get(&adev->dev, NULL);
2231	if (IS_ERR(pl022->clk)) {
2232		status = PTR_ERR(pl022->clk);
2233		dev_err(&adev->dev, "could not retrieve SSP/SPI bus clock\n");
2234		goto err_no_clk;
2235	}
2236
2237	status = clk_prepare_enable(pl022->clk);
2238	if (status) {
2239		dev_err(&adev->dev, "could not enable SSP/SPI bus clock\n");
2240		goto err_no_clk_en;
2241	}
2242
2243	/* Initialize transfer pump */
2244	tasklet_init(&pl022->pump_transfers, pump_transfers,
2245		     (unsigned long)pl022);
2246
2247	/* Disable SSP */
2248	writew((readw(SSP_CR1(pl022->virtbase)) & (~SSP_CR1_MASK_SSE)),
2249	       SSP_CR1(pl022->virtbase));
2250	load_ssp_default_config(pl022);
2251
2252	status = devm_request_irq(dev, adev->irq[0], pl022_interrupt_handler,
2253				  0, "pl022", pl022);
2254	if (status < 0) {
2255		dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
2256		goto err_no_irq;
2257	}
2258
2259	/* Get DMA channels, try autoconfiguration first */
2260	status = pl022_dma_autoprobe(pl022);
2261	if (status == -EPROBE_DEFER) {
2262		dev_dbg(dev, "deferring probe to get DMA channel\n");
2263		goto err_no_irq;
2264	}
2265
2266	/* If that failed, use channels from platform_info */
2267	if (status == 0)
2268		platform_info->enable_dma = 1;
2269	else if (platform_info->enable_dma) {
2270		status = pl022_dma_probe(pl022);
2271		if (status != 0)
2272			platform_info->enable_dma = 0;
2273	}
2274
2275	/* Register with the SPI framework */
2276	amba_set_drvdata(adev, pl022);
2277	status = devm_spi_register_master(&adev->dev, master);
2278	if (status != 0) {
2279		dev_err(&adev->dev,
2280			"probe - problem registering spi master\n");
2281		goto err_spi_register;
2282	}
2283	dev_dbg(dev, "probe succeeded\n");
2284
2285	/* let runtime pm put suspend */
2286	if (platform_info->autosuspend_delay > 0) {
2287		dev_info(&adev->dev,
2288			"will use autosuspend for runtime pm, delay %dms\n",
2289			platform_info->autosuspend_delay);
2290		pm_runtime_set_autosuspend_delay(dev,
2291			platform_info->autosuspend_delay);
2292		pm_runtime_use_autosuspend(dev);
2293	}
2294	pm_runtime_put(dev);
2295
2296	return 0;
2297
2298 err_spi_register:
2299	if (platform_info->enable_dma)
2300		pl022_dma_remove(pl022);
2301 err_no_irq:
2302	clk_disable_unprepare(pl022->clk);
2303 err_no_clk_en:
2304 err_no_clk:
2305 err_no_ioremap:
2306	amba_release_regions(adev);
2307 err_no_ioregion:
2308 err_no_gpio:
2309 err_no_mem:
2310	spi_master_put(master);
2311	return status;
2312}
2313
2314static int
2315pl022_remove(struct amba_device *adev)
2316{
2317	struct pl022 *pl022 = amba_get_drvdata(adev);
2318
2319	if (!pl022)
2320		return 0;
2321
2322	/*
2323	 * undo pm_runtime_put() in probe.  I assume that we're not
2324	 * accessing the primecell here.
2325	 */
2326	pm_runtime_get_noresume(&adev->dev);
2327
2328	load_ssp_default_config(pl022);
2329	if (pl022->master_info->enable_dma)
2330		pl022_dma_remove(pl022);
2331
2332	clk_disable_unprepare(pl022->clk);
2333	amba_release_regions(adev);
2334	tasklet_disable(&pl022->pump_transfers);
2335	return 0;
2336}
2337
2338#ifdef CONFIG_PM_SLEEP
2339static int pl022_suspend(struct device *dev)
2340{
2341	struct pl022 *pl022 = dev_get_drvdata(dev);
2342	int ret;
2343
2344	ret = spi_master_suspend(pl022->master);
2345	if (ret)
 
2346		return ret;
 
2347
2348	ret = pm_runtime_force_suspend(dev);
2349	if (ret) {
2350		spi_master_resume(pl022->master);
2351		return ret;
2352	}
2353
2354	pinctrl_pm_select_sleep_state(dev);
2355
2356	dev_dbg(dev, "suspended\n");
2357	return 0;
2358}
2359
2360static int pl022_resume(struct device *dev)
2361{
2362	struct pl022 *pl022 = dev_get_drvdata(dev);
2363	int ret;
2364
2365	ret = pm_runtime_force_resume(dev);
2366	if (ret)
2367		dev_err(dev, "problem resuming\n");
2368
2369	/* Start the queue running */
2370	ret = spi_master_resume(pl022->master);
2371	if (!ret)
 
 
2372		dev_dbg(dev, "resumed\n");
2373
2374	return ret;
2375}
2376#endif
2377
2378#ifdef CONFIG_PM
2379static int pl022_runtime_suspend(struct device *dev)
2380{
2381	struct pl022 *pl022 = dev_get_drvdata(dev);
2382
2383	clk_disable_unprepare(pl022->clk);
2384	pinctrl_pm_select_idle_state(dev);
2385
2386	return 0;
2387}
2388
2389static int pl022_runtime_resume(struct device *dev)
2390{
2391	struct pl022 *pl022 = dev_get_drvdata(dev);
2392
2393	pinctrl_pm_select_default_state(dev);
2394	clk_prepare_enable(pl022->clk);
2395
2396	return 0;
2397}
2398#endif
2399
2400static const struct dev_pm_ops pl022_dev_pm_ops = {
2401	SET_SYSTEM_SLEEP_PM_OPS(pl022_suspend, pl022_resume)
2402	SET_RUNTIME_PM_OPS(pl022_runtime_suspend, pl022_runtime_resume, NULL)
2403};
2404
2405static struct vendor_data vendor_arm = {
2406	.fifodepth = 8,
2407	.max_bpw = 16,
2408	.unidir = false,
2409	.extended_cr = false,
2410	.pl023 = false,
2411	.loopback = true,
2412	.internal_cs_ctrl = false,
2413};
2414
2415static struct vendor_data vendor_st = {
2416	.fifodepth = 32,
2417	.max_bpw = 32,
2418	.unidir = false,
2419	.extended_cr = true,
2420	.pl023 = false,
2421	.loopback = true,
2422	.internal_cs_ctrl = false,
2423};
2424
2425static struct vendor_data vendor_st_pl023 = {
2426	.fifodepth = 32,
2427	.max_bpw = 32,
2428	.unidir = false,
2429	.extended_cr = true,
2430	.pl023 = true,
2431	.loopback = false,
2432	.internal_cs_ctrl = false,
2433};
2434
2435static struct vendor_data vendor_lsi = {
2436	.fifodepth = 8,
2437	.max_bpw = 16,
2438	.unidir = false,
2439	.extended_cr = false,
2440	.pl023 = false,
2441	.loopback = true,
2442	.internal_cs_ctrl = true,
2443};
2444
2445static const struct amba_id pl022_ids[] = {
2446	{
2447		/*
2448		 * ARM PL022 variant, this has a 16bit wide
2449		 * and 8 locations deep TX/RX FIFO
2450		 */
2451		.id	= 0x00041022,
2452		.mask	= 0x000fffff,
2453		.data	= &vendor_arm,
2454	},
2455	{
2456		/*
2457		 * ST Micro derivative, this has 32bit wide
2458		 * and 32 locations deep TX/RX FIFO
2459		 */
2460		.id	= 0x01080022,
2461		.mask	= 0xffffffff,
2462		.data	= &vendor_st,
2463	},
2464	{
2465		/*
2466		 * ST-Ericsson derivative "PL023" (this is not
2467		 * an official ARM number), this is a PL022 SSP block
2468		 * stripped to SPI mode only, it has 32bit wide
2469		 * and 32 locations deep TX/RX FIFO but no extended
2470		 * CR0/CR1 register
2471		 */
2472		.id	= 0x00080023,
2473		.mask	= 0xffffffff,
2474		.data	= &vendor_st_pl023,
2475	},
2476	{
2477		/*
2478		 * PL022 variant that has a chip select control register whih
2479		 * allows control of 5 output signals nCS[0:4].
2480		 */
2481		.id	= 0x000b6022,
2482		.mask	= 0x000fffff,
2483		.data	= &vendor_lsi,
2484	},
2485	{ 0, 0 },
2486};
2487
2488MODULE_DEVICE_TABLE(amba, pl022_ids);
2489
2490static struct amba_driver pl022_driver = {
2491	.drv = {
2492		.name	= "ssp-pl022",
2493		.pm	= &pl022_dev_pm_ops,
2494	},
2495	.id_table	= pl022_ids,
2496	.probe		= pl022_probe,
2497	.remove		= pl022_remove,
2498};
2499
2500static int __init pl022_init(void)
2501{
2502	return amba_driver_register(&pl022_driver);
2503}
2504subsys_initcall(pl022_init);
2505
2506static void __exit pl022_exit(void)
2507{
2508	amba_driver_unregister(&pl022_driver);
2509}
2510module_exit(pl022_exit);
2511
2512MODULE_AUTHOR("Linus Walleij <linus.walleij@stericsson.com>");
2513MODULE_DESCRIPTION("PL022 SSP Controller Driver");
2514MODULE_LICENSE("GPL");