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v6.13.7
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * OMAP2 McSPI controller driver
   4 *
   5 * Copyright (C) 2005, 2006 Nokia Corporation
   6 * Author:	Samuel Ortiz <samuel.ortiz@nokia.com> and
   7 *		Juha Yrjola <juha.yrjola@nokia.com>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/interrupt.h>
  12#include <linux/module.h>
  13#include <linux/device.h>
  14#include <linux/delay.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/dmaengine.h>
  17#include <linux/pinctrl/consumer.h>
  18#include <linux/platform_device.h>
  19#include <linux/err.h>
  20#include <linux/clk.h>
  21#include <linux/io.h>
  22#include <linux/slab.h>
  23#include <linux/pm_runtime.h>
  24#include <linux/of.h>
  25#include <linux/of_device.h>
  26#include <linux/gcd.h>
  27
  28#include <linux/spi/spi.h>
  29
  30#include "internals.h"
  31
  32#include <linux/platform_data/spi-omap2-mcspi.h>
  33
  34#define OMAP2_MCSPI_MAX_FREQ		48000000
  35#define OMAP2_MCSPI_MAX_DIVIDER		4096
  36#define OMAP2_MCSPI_MAX_FIFODEPTH	64
  37#define OMAP2_MCSPI_MAX_FIFOWCNT	0xFFFF
  38#define SPI_AUTOSUSPEND_TIMEOUT		2000
  39
  40#define OMAP2_MCSPI_REVISION		0x00
  41#define OMAP2_MCSPI_SYSSTATUS		0x14
  42#define OMAP2_MCSPI_IRQSTATUS		0x18
  43#define OMAP2_MCSPI_IRQENABLE		0x1c
  44#define OMAP2_MCSPI_WAKEUPENABLE	0x20
  45#define OMAP2_MCSPI_SYST		0x24
  46#define OMAP2_MCSPI_MODULCTRL		0x28
  47#define OMAP2_MCSPI_XFERLEVEL		0x7c
  48
  49/* per-channel banks, 0x14 bytes each, first is: */
  50#define OMAP2_MCSPI_CHCONF0		0x2c
  51#define OMAP2_MCSPI_CHSTAT0		0x30
  52#define OMAP2_MCSPI_CHCTRL0		0x34
  53#define OMAP2_MCSPI_TX0			0x38
  54#define OMAP2_MCSPI_RX0			0x3c
  55
  56/* per-register bitmasks: */
  57#define OMAP2_MCSPI_IRQSTATUS_EOW	BIT(17)
  58
  59#define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
  60#define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
  61#define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
  62
  63#define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
  64#define OMAP2_MCSPI_CHCONF_POL		BIT(1)
  65#define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
  66#define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
  67#define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
  68#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
  69#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
  70#define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
  71#define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
  72#define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
  73#define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
  74#define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
  75#define OMAP2_MCSPI_CHCONF_IS		BIT(18)
  76#define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
  77#define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
  78#define OMAP2_MCSPI_CHCONF_FFET		BIT(27)
  79#define OMAP2_MCSPI_CHCONF_FFER		BIT(28)
  80#define OMAP2_MCSPI_CHCONF_CLKG		BIT(29)
  81
  82#define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
  83#define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
  84#define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
  85#define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
  86
  87#define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
  88#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK	(0xff << 8)
  89
  90#define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
  91
  92/* We have 2 DMA channels per CS, one for RX and one for TX */
  93struct omap2_mcspi_dma {
  94	struct dma_chan *dma_tx;
  95	struct dma_chan *dma_rx;
  96
  97	struct completion dma_tx_completion;
  98	struct completion dma_rx_completion;
  99
 100	char dma_rx_ch_name[14];
 101	char dma_tx_ch_name[14];
 102};
 103
 104/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
 105 * cache operations; better heuristics consider wordsize and bitrate.
 106 */
 107#define DMA_MIN_BYTES			160
 108
 109
 110/*
 111 * Used for context save and restore, structure members to be updated whenever
 112 * corresponding registers are modified.
 113 */
 114struct omap2_mcspi_regs {
 115	u32 modulctrl;
 116	u32 wakeupenable;
 117	struct list_head cs;
 118};
 119
 120struct omap2_mcspi {
 121	struct completion	txdone;
 122	struct spi_controller	*ctlr;
 123	/* Virtual base address of the controller */
 124	void __iomem		*base;
 125	unsigned long		phys;
 126	/* SPI1 has 4 channels, while SPI2 has 2 */
 127	struct omap2_mcspi_dma	*dma_channels;
 128	struct device		*dev;
 129	struct omap2_mcspi_regs ctx;
 130	struct clk		*ref_clk;
 131	int			fifo_depth;
 132	bool			target_aborted;
 133	unsigned int		pin_dir:1;
 134	size_t			max_xfer_len;
 135	u32			ref_clk_hz;
 136	bool			use_multi_mode;
 137};
 138
 139struct omap2_mcspi_cs {
 140	void __iomem		*base;
 141	unsigned long		phys;
 142	int			word_len;
 143	u16			mode;
 144	struct list_head	node;
 145	/* Context save and restore shadow register */
 146	u32			chconf0, chctrl0;
 147};
 148
 149static inline void mcspi_write_reg(struct spi_controller *ctlr,
 150		int idx, u32 val)
 151{
 152	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
 153
 154	writel_relaxed(val, mcspi->base + idx);
 155}
 156
 157static inline u32 mcspi_read_reg(struct spi_controller *ctlr, int idx)
 158{
 159	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
 160
 161	return readl_relaxed(mcspi->base + idx);
 162}
 163
 164static inline void mcspi_write_cs_reg(const struct spi_device *spi,
 165		int idx, u32 val)
 166{
 167	struct omap2_mcspi_cs	*cs = spi->controller_state;
 168
 169	writel_relaxed(val, cs->base +  idx);
 170}
 171
 172static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
 173{
 174	struct omap2_mcspi_cs	*cs = spi->controller_state;
 175
 176	return readl_relaxed(cs->base + idx);
 177}
 178
 179static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
 180{
 181	struct omap2_mcspi_cs *cs = spi->controller_state;
 182
 183	return cs->chconf0;
 184}
 185
 186static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
 187{
 188	struct omap2_mcspi_cs *cs = spi->controller_state;
 189
 190	cs->chconf0 = val;
 191	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
 192	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 193}
 194
 195static inline int mcspi_bytes_per_word(int word_len)
 196{
 197	if (word_len <= 8)
 198		return 1;
 199	else if (word_len <= 16)
 200		return 2;
 201	else /* word_len <= 32 */
 202		return 4;
 203}
 204
 205static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 206		int is_read, int enable)
 207{
 208	u32 l, rw;
 209
 210	l = mcspi_cached_chconf0(spi);
 211
 212	if (is_read) /* 1 is read, 0 write */
 213		rw = OMAP2_MCSPI_CHCONF_DMAR;
 214	else
 215		rw = OMAP2_MCSPI_CHCONF_DMAW;
 216
 217	if (enable)
 218		l |= rw;
 219	else
 220		l &= ~rw;
 221
 222	mcspi_write_chconf0(spi, l);
 223}
 224
 225static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 226{
 227	struct omap2_mcspi_cs *cs = spi->controller_state;
 228	u32 l;
 229
 230	l = cs->chctrl0;
 231	if (enable)
 232		l |= OMAP2_MCSPI_CHCTRL_EN;
 233	else
 234		l &= ~OMAP2_MCSPI_CHCTRL_EN;
 235	cs->chctrl0 = l;
 236	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 237	/* Flash post-writes */
 238	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
 239}
 240
 241static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
 242{
 243	struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
 244	u32 l;
 245
 246	/* The controller handles the inverted chip selects
 247	 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
 248	 * the inversion from the core spi_set_cs function.
 249	 */
 250	if (spi->mode & SPI_CS_HIGH)
 251		enable = !enable;
 252
 253	if (spi->controller_state) {
 254		int err = pm_runtime_resume_and_get(mcspi->dev);
 255		if (err < 0) {
 
 256			dev_err(mcspi->dev, "failed to get sync: %d\n", err);
 257			return;
 258		}
 259
 260		l = mcspi_cached_chconf0(spi);
 261
 262		/* Only enable chip select manually if single mode is used */
 263		if (mcspi->use_multi_mode) {
 264			l &= ~OMAP2_MCSPI_CHCONF_FORCE;
 265		} else {
 266			if (enable)
 267				l &= ~OMAP2_MCSPI_CHCONF_FORCE;
 268			else
 269				l |= OMAP2_MCSPI_CHCONF_FORCE;
 270		}
 271
 272		mcspi_write_chconf0(spi, l);
 273
 274		pm_runtime_mark_last_busy(mcspi->dev);
 275		pm_runtime_put_autosuspend(mcspi->dev);
 276	}
 277}
 278
 279static void omap2_mcspi_set_mode(struct spi_controller *ctlr)
 280{
 281	struct omap2_mcspi	*mcspi = spi_controller_get_devdata(ctlr);
 282	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
 283	u32 l;
 284
 285	/*
 286	 * Choose host or target mode
 287	 */
 288	l = mcspi_read_reg(ctlr, OMAP2_MCSPI_MODULCTRL);
 289	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
 290	if (spi_controller_is_target(ctlr)) {
 291		l |= (OMAP2_MCSPI_MODULCTRL_MS);
 292	} else {
 293		l &= ~(OMAP2_MCSPI_MODULCTRL_MS);
 294
 295		/* Enable single mode if needed */
 296		if (mcspi->use_multi_mode)
 297			l &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
 298		else
 299			l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
 300	}
 301	mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, l);
 302
 303	ctx->modulctrl = l;
 304}
 305
 306static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 307				struct spi_transfer *t, int enable)
 308{
 309	struct spi_controller *ctlr = spi->controller;
 310	struct omap2_mcspi_cs *cs = spi->controller_state;
 311	struct omap2_mcspi *mcspi;
 312	unsigned int wcnt;
 313	int max_fifo_depth, bytes_per_word;
 314	u32 chconf, xferlevel;
 315
 316	mcspi = spi_controller_get_devdata(ctlr);
 317
 318	chconf = mcspi_cached_chconf0(spi);
 319	if (enable) {
 320		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
 321		if (t->len % bytes_per_word != 0)
 322			goto disable_fifo;
 323
 324		if (t->rx_buf != NULL && t->tx_buf != NULL)
 325			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
 326		else
 327			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
 328
 329		wcnt = t->len / bytes_per_word;
 330		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
 331			goto disable_fifo;
 332
 333		xferlevel = wcnt << 16;
 334		if (t->rx_buf != NULL) {
 335			chconf |= OMAP2_MCSPI_CHCONF_FFER;
 336			xferlevel |= (bytes_per_word - 1) << 8;
 337		}
 338
 339		if (t->tx_buf != NULL) {
 340			chconf |= OMAP2_MCSPI_CHCONF_FFET;
 341			xferlevel |= bytes_per_word - 1;
 342		}
 343
 344		mcspi_write_reg(ctlr, OMAP2_MCSPI_XFERLEVEL, xferlevel);
 345		mcspi_write_chconf0(spi, chconf);
 346		mcspi->fifo_depth = max_fifo_depth;
 347
 348		return;
 349	}
 350
 351disable_fifo:
 352	if (t->rx_buf != NULL)
 353		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
 354
 355	if (t->tx_buf != NULL)
 356		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
 357
 358	mcspi_write_chconf0(spi, chconf);
 359	mcspi->fifo_depth = 0;
 360}
 361
 362static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 363{
 364	unsigned long timeout;
 365
 366	timeout = jiffies + msecs_to_jiffies(1000);
 367	while (!(readl_relaxed(reg) & bit)) {
 368		if (time_after(jiffies, timeout)) {
 369			if (!(readl_relaxed(reg) & bit))
 370				return -ETIMEDOUT;
 371			else
 372				return 0;
 373		}
 374		cpu_relax();
 375	}
 376	return 0;
 377}
 378
 379static int mcspi_wait_for_completion(struct  omap2_mcspi *mcspi,
 380				     struct completion *x)
 381{
 382	if (spi_controller_is_target(mcspi->ctlr)) {
 383		if (wait_for_completion_interruptible(x) ||
 384		    mcspi->target_aborted)
 385			return -EINTR;
 386	} else {
 387		wait_for_completion(x);
 388	}
 389
 390	return 0;
 391}
 392
 393static void omap2_mcspi_rx_callback(void *data)
 394{
 395	struct spi_device *spi = data;
 396	struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
 397	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
 398
 399	/* We must disable the DMA RX request */
 400	omap2_mcspi_set_dma_req(spi, 1, 0);
 401
 402	complete(&mcspi_dma->dma_rx_completion);
 403}
 404
 405static void omap2_mcspi_tx_callback(void *data)
 406{
 407	struct spi_device *spi = data;
 408	struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
 409	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
 410
 411	/* We must disable the DMA TX request */
 412	omap2_mcspi_set_dma_req(spi, 0, 0);
 413
 414	complete(&mcspi_dma->dma_tx_completion);
 415}
 416
 417static void omap2_mcspi_tx_dma(struct spi_device *spi,
 418				struct spi_transfer *xfer,
 419				struct dma_slave_config cfg)
 420{
 421	struct omap2_mcspi	*mcspi;
 422	struct omap2_mcspi_dma  *mcspi_dma;
 423	struct dma_async_tx_descriptor *tx;
 424
 425	mcspi = spi_controller_get_devdata(spi->controller);
 426	mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
 427
 428	dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
 429
 430	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
 431				     xfer->tx_sg.nents,
 432				     DMA_MEM_TO_DEV,
 433				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 434	if (tx) {
 435		tx->callback = omap2_mcspi_tx_callback;
 436		tx->callback_param = spi;
 437		dmaengine_submit(tx);
 438	} else {
 439		/* FIXME: fall back to PIO? */
 440	}
 441	dma_async_issue_pending(mcspi_dma->dma_tx);
 442	omap2_mcspi_set_dma_req(spi, 0, 1);
 443}
 444
 445static unsigned
 446omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 447				struct dma_slave_config cfg,
 448				unsigned es)
 449{
 450	struct omap2_mcspi	*mcspi;
 451	struct omap2_mcspi_dma  *mcspi_dma;
 452	unsigned int		count, transfer_reduction = 0;
 453	struct scatterlist	*sg_out[2];
 454	int			nb_sizes = 0, out_mapped_nents[2], ret, x;
 455	size_t			sizes[2];
 456	u32			l;
 457	int			elements = 0;
 458	int			word_len, element_count;
 459	struct omap2_mcspi_cs	*cs = spi->controller_state;
 460	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 461	struct dma_async_tx_descriptor *tx;
 462
 463	mcspi = spi_controller_get_devdata(spi->controller);
 464	mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
 465	count = xfer->len;
 466
 467	/*
 468	 *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
 469	 *  it mentions reducing DMA transfer length by one element in host
 470	 *  normal mode.
 471	 */
 472	if (mcspi->fifo_depth == 0)
 473		transfer_reduction = es;
 474
 475	word_len = cs->word_len;
 476	l = mcspi_cached_chconf0(spi);
 477
 478	if (word_len <= 8)
 479		element_count = count;
 480	else if (word_len <= 16)
 481		element_count = count >> 1;
 482	else /* word_len <= 32 */
 483		element_count = count >> 2;
 484
 485
 486	dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
 487
 488	/*
 489	 *  Reduce DMA transfer length by one more if McSPI is
 490	 *  configured in turbo mode.
 491	 */
 492	if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
 493		transfer_reduction += es;
 494
 495	if (transfer_reduction) {
 496		/* Split sgl into two. The second sgl won't be used. */
 497		sizes[0] = count - transfer_reduction;
 498		sizes[1] = transfer_reduction;
 499		nb_sizes = 2;
 500	} else {
 501		/*
 502		 * Don't bother splitting the sgl. This essentially
 503		 * clones the original sgl.
 504		 */
 505		sizes[0] = count;
 506		nb_sizes = 1;
 507	}
 508
 509	ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
 510		       sizes, sg_out, out_mapped_nents, GFP_KERNEL);
 511
 512	if (ret < 0) {
 513		dev_err(&spi->dev, "sg_split failed\n");
 514		return 0;
 515	}
 516
 517	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
 518				     out_mapped_nents[0], DMA_DEV_TO_MEM,
 519				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 520	if (tx) {
 521		tx->callback = omap2_mcspi_rx_callback;
 522		tx->callback_param = spi;
 523		dmaengine_submit(tx);
 524	} else {
 525		/* FIXME: fall back to PIO? */
 526	}
 527
 528	dma_async_issue_pending(mcspi_dma->dma_rx);
 529	omap2_mcspi_set_dma_req(spi, 1, 1);
 530
 531	ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
 532	if (ret || mcspi->target_aborted) {
 533		dmaengine_terminate_sync(mcspi_dma->dma_rx);
 534		omap2_mcspi_set_dma_req(spi, 1, 0);
 535		return 0;
 536	}
 537
 538	for (x = 0; x < nb_sizes; x++)
 539		kfree(sg_out[x]);
 540
 541	if (mcspi->fifo_depth > 0)
 542		return count;
 543
 544	/*
 545	 *  Due to the DMA transfer length reduction the missing bytes must
 546	 *  be read manually to receive all of the expected data.
 547	 */
 548	omap2_mcspi_set_enable(spi, 0);
 549
 550	elements = element_count - 1;
 551
 552	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
 553		elements--;
 554
 555		if (!mcspi_wait_for_reg_bit(chstat_reg,
 556					    OMAP2_MCSPI_CHSTAT_RXS)) {
 557			u32 w;
 558
 559			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 560			if (word_len <= 8)
 561				((u8 *)xfer->rx_buf)[elements++] = w;
 562			else if (word_len <= 16)
 563				((u16 *)xfer->rx_buf)[elements++] = w;
 564			else /* word_len <= 32 */
 565				((u32 *)xfer->rx_buf)[elements++] = w;
 566		} else {
 567			int bytes_per_word = mcspi_bytes_per_word(word_len);
 568			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
 569			count -= (bytes_per_word << 1);
 570			omap2_mcspi_set_enable(spi, 1);
 571			return count;
 572		}
 573	}
 574	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
 575		u32 w;
 576
 577		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 578		if (word_len <= 8)
 579			((u8 *)xfer->rx_buf)[elements] = w;
 580		else if (word_len <= 16)
 581			((u16 *)xfer->rx_buf)[elements] = w;
 582		else /* word_len <= 32 */
 583			((u32 *)xfer->rx_buf)[elements] = w;
 584	} else {
 585		dev_err(&spi->dev, "DMA RX last word empty\n");
 586		count -= mcspi_bytes_per_word(word_len);
 587	}
 588	omap2_mcspi_set_enable(spi, 1);
 589	return count;
 590}
 591
 592static unsigned
 593omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
 594{
 595	struct omap2_mcspi	*mcspi;
 596	struct omap2_mcspi_cs	*cs = spi->controller_state;
 597	struct omap2_mcspi_dma  *mcspi_dma;
 598	unsigned int		count;
 599	u8			*rx;
 600	const u8		*tx;
 601	struct dma_slave_config	cfg;
 602	enum dma_slave_buswidth width;
 603	unsigned es;
 604	void __iomem		*chstat_reg;
 605	void __iomem            *irqstat_reg;
 606	int			wait_res;
 607
 608	mcspi = spi_controller_get_devdata(spi->controller);
 609	mcspi_dma = &mcspi->dma_channels[spi_get_chipselect(spi, 0)];
 610
 611	if (cs->word_len <= 8) {
 612		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 613		es = 1;
 614	} else if (cs->word_len <= 16) {
 615		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 616		es = 2;
 617	} else {
 618		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 619		es = 4;
 620	}
 621
 622	count = xfer->len;
 623
 624	memset(&cfg, 0, sizeof(cfg));
 625	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
 626	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
 627	cfg.src_addr_width = width;
 628	cfg.dst_addr_width = width;
 629	cfg.src_maxburst = 1;
 630	cfg.dst_maxburst = 1;
 631
 632	rx = xfer->rx_buf;
 633	tx = xfer->tx_buf;
 634
 635	mcspi->target_aborted = false;
 636	reinit_completion(&mcspi_dma->dma_tx_completion);
 637	reinit_completion(&mcspi_dma->dma_rx_completion);
 638	reinit_completion(&mcspi->txdone);
 639	if (tx) {
 640		/* Enable EOW IRQ to know end of tx in target mode */
 641		if (spi_controller_is_target(spi->controller))
 642			mcspi_write_reg(spi->controller,
 643					OMAP2_MCSPI_IRQENABLE,
 644					OMAP2_MCSPI_IRQSTATUS_EOW);
 645		omap2_mcspi_tx_dma(spi, xfer, cfg);
 646	}
 647
 648	if (rx != NULL)
 649		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
 650
 651	if (tx != NULL) {
 652		int ret;
 653
 654		ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
 655		if (ret || mcspi->target_aborted) {
 656			dmaengine_terminate_sync(mcspi_dma->dma_tx);
 657			omap2_mcspi_set_dma_req(spi, 0, 0);
 658			return 0;
 659		}
 660
 661		if (spi_controller_is_target(mcspi->ctlr)) {
 662			ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
 663			if (ret || mcspi->target_aborted)
 664				return 0;
 665		}
 666
 667		if (mcspi->fifo_depth > 0) {
 668			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
 669
 670			if (mcspi_wait_for_reg_bit(irqstat_reg,
 671						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
 672				dev_err(&spi->dev, "EOW timed out\n");
 673
 674			mcspi_write_reg(mcspi->ctlr, OMAP2_MCSPI_IRQSTATUS,
 675					OMAP2_MCSPI_IRQSTATUS_EOW);
 676		}
 677
 678		/* for TX_ONLY mode, be sure all words have shifted out */
 679		if (rx == NULL) {
 680			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 681			if (mcspi->fifo_depth > 0) {
 682				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 683						OMAP2_MCSPI_CHSTAT_TXFFE);
 684				if (wait_res < 0)
 685					dev_err(&spi->dev, "TXFFE timed out\n");
 686			} else {
 687				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 688						OMAP2_MCSPI_CHSTAT_TXS);
 689				if (wait_res < 0)
 690					dev_err(&spi->dev, "TXS timed out\n");
 691			}
 692			if (wait_res >= 0 &&
 693				(mcspi_wait_for_reg_bit(chstat_reg,
 694					OMAP2_MCSPI_CHSTAT_EOT) < 0))
 695				dev_err(&spi->dev, "EOT timed out\n");
 696		}
 697	}
 698	return count;
 699}
 700
 701static unsigned
 702omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 703{
 704	struct omap2_mcspi_cs	*cs = spi->controller_state;
 705	unsigned int		count, c;
 706	u32			l;
 707	void __iomem		*base = cs->base;
 708	void __iomem		*tx_reg;
 709	void __iomem		*rx_reg;
 710	void __iomem		*chstat_reg;
 711	int			word_len;
 712
 713	count = xfer->len;
 714	c = count;
 715	word_len = cs->word_len;
 716
 717	l = mcspi_cached_chconf0(spi);
 718
 719	/* We store the pre-calculated register addresses on stack to speed
 720	 * up the transfer loop. */
 721	tx_reg		= base + OMAP2_MCSPI_TX0;
 722	rx_reg		= base + OMAP2_MCSPI_RX0;
 723	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
 724
 725	if (c < (word_len>>3))
 726		return 0;
 727
 728	if (word_len <= 8) {
 729		u8		*rx;
 730		const u8	*tx;
 731
 732		rx = xfer->rx_buf;
 733		tx = xfer->tx_buf;
 734
 735		do {
 736			c -= 1;
 737			if (tx != NULL) {
 738				if (mcspi_wait_for_reg_bit(chstat_reg,
 739						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 740					dev_err(&spi->dev, "TXS timed out\n");
 741					goto out;
 742				}
 743				dev_vdbg(&spi->dev, "write-%d %02x\n",
 744						word_len, *tx);
 745				writel_relaxed(*tx++, tx_reg);
 746			}
 747			if (rx != NULL) {
 748				if (mcspi_wait_for_reg_bit(chstat_reg,
 749						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 750					dev_err(&spi->dev, "RXS timed out\n");
 751					goto out;
 752				}
 753
 754				if (c == 1 && tx == NULL &&
 755				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 756					omap2_mcspi_set_enable(spi, 0);
 757					*rx++ = readl_relaxed(rx_reg);
 758					dev_vdbg(&spi->dev, "read-%d %02x\n",
 759						    word_len, *(rx - 1));
 760					if (mcspi_wait_for_reg_bit(chstat_reg,
 761						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 762						dev_err(&spi->dev,
 763							"RXS timed out\n");
 764						goto out;
 765					}
 766					c = 0;
 767				} else if (c == 0 && tx == NULL) {
 768					omap2_mcspi_set_enable(spi, 0);
 769				}
 770
 771				*rx++ = readl_relaxed(rx_reg);
 772				dev_vdbg(&spi->dev, "read-%d %02x\n",
 773						word_len, *(rx - 1));
 774			}
 775			/* Add word delay between each word */
 776			spi_delay_exec(&xfer->word_delay, xfer);
 777		} while (c);
 778	} else if (word_len <= 16) {
 779		u16		*rx;
 780		const u16	*tx;
 781
 782		rx = xfer->rx_buf;
 783		tx = xfer->tx_buf;
 784		do {
 785			c -= 2;
 786			if (tx != NULL) {
 787				if (mcspi_wait_for_reg_bit(chstat_reg,
 788						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 789					dev_err(&spi->dev, "TXS timed out\n");
 790					goto out;
 791				}
 792				dev_vdbg(&spi->dev, "write-%d %04x\n",
 793						word_len, *tx);
 794				writel_relaxed(*tx++, tx_reg);
 795			}
 796			if (rx != NULL) {
 797				if (mcspi_wait_for_reg_bit(chstat_reg,
 798						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 799					dev_err(&spi->dev, "RXS timed out\n");
 800					goto out;
 801				}
 802
 803				if (c == 2 && tx == NULL &&
 804				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 805					omap2_mcspi_set_enable(spi, 0);
 806					*rx++ = readl_relaxed(rx_reg);
 807					dev_vdbg(&spi->dev, "read-%d %04x\n",
 808						    word_len, *(rx - 1));
 809					if (mcspi_wait_for_reg_bit(chstat_reg,
 810						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 811						dev_err(&spi->dev,
 812							"RXS timed out\n");
 813						goto out;
 814					}
 815					c = 0;
 816				} else if (c == 0 && tx == NULL) {
 817					omap2_mcspi_set_enable(spi, 0);
 818				}
 819
 820				*rx++ = readl_relaxed(rx_reg);
 821				dev_vdbg(&spi->dev, "read-%d %04x\n",
 822						word_len, *(rx - 1));
 823			}
 824			/* Add word delay between each word */
 825			spi_delay_exec(&xfer->word_delay, xfer);
 826		} while (c >= 2);
 827	} else if (word_len <= 32) {
 828		u32		*rx;
 829		const u32	*tx;
 830
 831		rx = xfer->rx_buf;
 832		tx = xfer->tx_buf;
 833		do {
 834			c -= 4;
 835			if (tx != NULL) {
 836				if (mcspi_wait_for_reg_bit(chstat_reg,
 837						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 838					dev_err(&spi->dev, "TXS timed out\n");
 839					goto out;
 840				}
 841				dev_vdbg(&spi->dev, "write-%d %08x\n",
 842						word_len, *tx);
 843				writel_relaxed(*tx++, tx_reg);
 844			}
 845			if (rx != NULL) {
 846				if (mcspi_wait_for_reg_bit(chstat_reg,
 847						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 848					dev_err(&spi->dev, "RXS timed out\n");
 849					goto out;
 850				}
 851
 852				if (c == 4 && tx == NULL &&
 853				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 854					omap2_mcspi_set_enable(spi, 0);
 855					*rx++ = readl_relaxed(rx_reg);
 856					dev_vdbg(&spi->dev, "read-%d %08x\n",
 857						    word_len, *(rx - 1));
 858					if (mcspi_wait_for_reg_bit(chstat_reg,
 859						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 860						dev_err(&spi->dev,
 861							"RXS timed out\n");
 862						goto out;
 863					}
 864					c = 0;
 865				} else if (c == 0 && tx == NULL) {
 866					omap2_mcspi_set_enable(spi, 0);
 867				}
 868
 869				*rx++ = readl_relaxed(rx_reg);
 870				dev_vdbg(&spi->dev, "read-%d %08x\n",
 871						word_len, *(rx - 1));
 872			}
 873			/* Add word delay between each word */
 874			spi_delay_exec(&xfer->word_delay, xfer);
 875		} while (c >= 4);
 876	}
 877
 878	/* for TX_ONLY mode, be sure all words have shifted out */
 879	if (xfer->rx_buf == NULL) {
 880		if (mcspi_wait_for_reg_bit(chstat_reg,
 881				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 882			dev_err(&spi->dev, "TXS timed out\n");
 883		} else if (mcspi_wait_for_reg_bit(chstat_reg,
 884				OMAP2_MCSPI_CHSTAT_EOT) < 0)
 885			dev_err(&spi->dev, "EOT timed out\n");
 886
 887		/* disable chan to purge rx datas received in TX_ONLY transfer,
 888		 * otherwise these rx datas will affect the direct following
 889		 * RX_ONLY transfer.
 890		 */
 891		omap2_mcspi_set_enable(spi, 0);
 892	}
 893out:
 894	omap2_mcspi_set_enable(spi, 1);
 895	return count - c;
 896}
 897
 898static u32 omap2_mcspi_calc_divisor(u32 speed_hz, u32 ref_clk_hz)
 899{
 900	u32 div;
 901
 902	for (div = 0; div < 15; div++)
 903		if (speed_hz >= (ref_clk_hz >> div))
 904			return div;
 905
 906	return 15;
 907}
 908
 909/* called only when no transfer is active to this device */
 910static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 911		struct spi_transfer *t)
 912{
 913	struct omap2_mcspi_cs *cs = spi->controller_state;
 914	struct omap2_mcspi *mcspi;
 915	u32 ref_clk_hz, l = 0, clkd = 0, div, extclk = 0, clkg = 0;
 916	u8 word_len = spi->bits_per_word;
 917	u32 speed_hz = spi->max_speed_hz;
 918
 919	mcspi = spi_controller_get_devdata(spi->controller);
 920
 921	if (t != NULL && t->bits_per_word)
 922		word_len = t->bits_per_word;
 923
 924	cs->word_len = word_len;
 925
 926	if (t && t->speed_hz)
 927		speed_hz = t->speed_hz;
 928
 929	ref_clk_hz = mcspi->ref_clk_hz;
 930	speed_hz = min_t(u32, speed_hz, ref_clk_hz);
 931	if (speed_hz < (ref_clk_hz / OMAP2_MCSPI_MAX_DIVIDER)) {
 932		clkd = omap2_mcspi_calc_divisor(speed_hz, ref_clk_hz);
 933		speed_hz = ref_clk_hz >> clkd;
 934		clkg = 0;
 935	} else {
 936		div = (ref_clk_hz + speed_hz - 1) / speed_hz;
 937		speed_hz = ref_clk_hz / div;
 938		clkd = (div - 1) & 0xf;
 939		extclk = (div - 1) >> 4;
 940		clkg = OMAP2_MCSPI_CHCONF_CLKG;
 941	}
 942
 943	l = mcspi_cached_chconf0(spi);
 944
 945	/* standard 4-wire host mode:  SCK, MOSI/out, MISO/in, nCS
 946	 * REVISIT: this controller could support SPI_3WIRE mode.
 947	 */
 948	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
 949		l &= ~OMAP2_MCSPI_CHCONF_IS;
 950		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
 951		l |= OMAP2_MCSPI_CHCONF_DPE0;
 952	} else {
 953		l |= OMAP2_MCSPI_CHCONF_IS;
 954		l |= OMAP2_MCSPI_CHCONF_DPE1;
 955		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
 956	}
 957
 958	/* wordlength */
 959	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
 960	l |= (word_len - 1) << 7;
 961
 962	/* set chipselect polarity; manage with FORCE */
 963	if (!(spi->mode & SPI_CS_HIGH))
 964		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
 965	else
 966		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
 967
 968	/* set clock divisor */
 969	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
 970	l |= clkd << 2;
 971
 972	/* set clock granularity */
 973	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
 974	l |= clkg;
 975	if (clkg) {
 976		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
 977		cs->chctrl0 |= extclk << 8;
 978		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 979	}
 980
 981	/* set SPI mode 0..3 */
 982	if (spi->mode & SPI_CPOL)
 983		l |= OMAP2_MCSPI_CHCONF_POL;
 984	else
 985		l &= ~OMAP2_MCSPI_CHCONF_POL;
 986	if (spi->mode & SPI_CPHA)
 987		l |= OMAP2_MCSPI_CHCONF_PHA;
 988	else
 989		l &= ~OMAP2_MCSPI_CHCONF_PHA;
 990
 991	mcspi_write_chconf0(spi, l);
 992
 993	cs->mode = spi->mode;
 994
 995	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
 996			speed_hz,
 997			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
 998			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
 999
1000	return 0;
1001}
1002
1003/*
1004 * Note that we currently allow DMA only if we get a channel
1005 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
1006 */
1007static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi,
1008				   struct omap2_mcspi_dma *mcspi_dma)
1009{
1010	int ret = 0;
1011
1012	mcspi_dma->dma_rx = dma_request_chan(mcspi->dev,
1013					     mcspi_dma->dma_rx_ch_name);
1014	if (IS_ERR(mcspi_dma->dma_rx)) {
1015		ret = PTR_ERR(mcspi_dma->dma_rx);
1016		mcspi_dma->dma_rx = NULL;
1017		goto no_dma;
1018	}
1019
1020	mcspi_dma->dma_tx = dma_request_chan(mcspi->dev,
1021					     mcspi_dma->dma_tx_ch_name);
1022	if (IS_ERR(mcspi_dma->dma_tx)) {
1023		ret = PTR_ERR(mcspi_dma->dma_tx);
1024		mcspi_dma->dma_tx = NULL;
1025		dma_release_channel(mcspi_dma->dma_rx);
1026		mcspi_dma->dma_rx = NULL;
1027	}
1028
1029	init_completion(&mcspi_dma->dma_rx_completion);
1030	init_completion(&mcspi_dma->dma_tx_completion);
1031
1032no_dma:
1033	return ret;
1034}
1035
1036static void omap2_mcspi_release_dma(struct spi_controller *ctlr)
1037{
1038	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1039	struct omap2_mcspi_dma	*mcspi_dma;
1040	int i;
1041
1042	for (i = 0; i < ctlr->num_chipselect; i++) {
1043		mcspi_dma = &mcspi->dma_channels[i];
1044
1045		if (mcspi_dma->dma_rx) {
1046			dma_release_channel(mcspi_dma->dma_rx);
1047			mcspi_dma->dma_rx = NULL;
1048		}
1049		if (mcspi_dma->dma_tx) {
1050			dma_release_channel(mcspi_dma->dma_tx);
1051			mcspi_dma->dma_tx = NULL;
1052		}
1053	}
1054}
1055
1056static void omap2_mcspi_cleanup(struct spi_device *spi)
1057{
1058	struct omap2_mcspi_cs	*cs;
1059
1060	if (spi->controller_state) {
1061		/* Unlink controller state from context save list */
1062		cs = spi->controller_state;
1063		list_del(&cs->node);
1064
1065		kfree(cs);
1066	}
1067}
1068
1069static int omap2_mcspi_setup(struct spi_device *spi)
1070{
1071	bool			initial_setup = false;
1072	int			ret;
1073	struct omap2_mcspi	*mcspi = spi_controller_get_devdata(spi->controller);
1074	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1075	struct omap2_mcspi_cs	*cs = spi->controller_state;
1076
1077	if (!cs) {
1078		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
1079		if (!cs)
1080			return -ENOMEM;
1081		cs->base = mcspi->base + spi_get_chipselect(spi, 0) * 0x14;
1082		cs->phys = mcspi->phys + spi_get_chipselect(spi, 0) * 0x14;
1083		cs->mode = 0;
1084		cs->chconf0 = 0;
1085		cs->chctrl0 = 0;
1086		spi->controller_state = cs;
1087		/* Link this to context save list */
1088		list_add_tail(&cs->node, &ctx->cs);
1089		initial_setup = true;
1090	}
1091
1092	ret = pm_runtime_resume_and_get(mcspi->dev);
1093	if (ret < 0) {
 
1094		if (initial_setup)
1095			omap2_mcspi_cleanup(spi);
1096
1097		return ret;
1098	}
1099
1100	ret = omap2_mcspi_setup_transfer(spi, NULL);
1101	if (ret && initial_setup)
1102		omap2_mcspi_cleanup(spi);
1103
1104	pm_runtime_mark_last_busy(mcspi->dev);
1105	pm_runtime_put_autosuspend(mcspi->dev);
1106
1107	return ret;
1108}
1109
1110static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
1111{
1112	struct omap2_mcspi *mcspi = data;
1113	u32 irqstat;
1114
1115	irqstat	= mcspi_read_reg(mcspi->ctlr, OMAP2_MCSPI_IRQSTATUS);
1116	if (!irqstat)
1117		return IRQ_NONE;
1118
1119	/* Disable IRQ and wakeup target xfer task */
1120	mcspi_write_reg(mcspi->ctlr, OMAP2_MCSPI_IRQENABLE, 0);
1121	if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1122		complete(&mcspi->txdone);
1123
1124	return IRQ_HANDLED;
1125}
1126
1127static int omap2_mcspi_target_abort(struct spi_controller *ctlr)
1128{
1129	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1130	struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1131
1132	mcspi->target_aborted = true;
1133	complete(&mcspi_dma->dma_rx_completion);
1134	complete(&mcspi_dma->dma_tx_completion);
1135	complete(&mcspi->txdone);
1136
1137	return 0;
1138}
1139
1140static int omap2_mcspi_transfer_one(struct spi_controller *ctlr,
1141				    struct spi_device *spi,
1142				    struct spi_transfer *t)
1143{
1144
1145	/* We only enable one channel at a time -- the one whose message is
1146	 * -- although this controller would gladly
1147	 * arbitrate among multiple channels.  This corresponds to "single
1148	 * channel" host mode.  As a side effect, we need to manage the
1149	 * chipselect with the FORCE bit ... CS != channel enable.
1150	 */
1151
1152	struct omap2_mcspi		*mcspi;
1153	struct omap2_mcspi_dma		*mcspi_dma;
1154	struct omap2_mcspi_cs		*cs;
1155	struct omap2_mcspi_device_config *cd;
1156	int				par_override = 0;
1157	int				status = 0;
1158	u32				chconf;
1159
1160	mcspi = spi_controller_get_devdata(ctlr);
1161	mcspi_dma = mcspi->dma_channels + spi_get_chipselect(spi, 0);
1162	cs = spi->controller_state;
1163	cd = spi->controller_data;
1164
1165	/*
1166	 * The target driver could have changed spi->mode in which case
1167	 * it will be different from cs->mode (the current hardware setup).
1168	 * If so, set par_override (even though its not a parity issue) so
1169	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1170	 * with the correct mode on the first iteration of the loop below.
1171	 */
1172	if (spi->mode != cs->mode)
1173		par_override = 1;
1174
1175	omap2_mcspi_set_enable(spi, 0);
1176
1177	if (spi_get_csgpiod(spi, 0))
1178		omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1179
1180	if (par_override ||
1181	    (t->speed_hz != spi->max_speed_hz) ||
1182	    (t->bits_per_word != spi->bits_per_word)) {
1183		par_override = 1;
1184		status = omap2_mcspi_setup_transfer(spi, t);
1185		if (status < 0)
1186			goto out;
1187		if (t->speed_hz == spi->max_speed_hz &&
1188		    t->bits_per_word == spi->bits_per_word)
1189			par_override = 0;
1190	}
 
 
 
 
 
 
 
1191
1192	chconf = mcspi_cached_chconf0(spi);
1193	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1194	chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1195
1196	if (t->tx_buf == NULL)
1197		chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1198	else if (t->rx_buf == NULL)
1199		chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1200
1201	if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1202		/* Turbo mode is for more than one word */
1203		if (t->len > ((cs->word_len + 7) >> 3))
1204			chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1205	}
1206
1207	mcspi_write_chconf0(spi, chconf);
1208
1209	if (t->len) {
1210		unsigned	count;
1211
1212		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1213		    spi_xfer_is_dma_mapped(ctlr, spi, t))
 
1214			omap2_mcspi_set_fifo(spi, t, 1);
1215
1216		omap2_mcspi_set_enable(spi, 1);
1217
1218		/* RX_ONLY mode needs dummy data in TX reg */
1219		if (t->tx_buf == NULL)
1220			writel_relaxed(0, cs->base
1221					+ OMAP2_MCSPI_TX0);
1222
1223		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1224		    spi_xfer_is_dma_mapped(ctlr, spi, t))
 
1225			count = omap2_mcspi_txrx_dma(spi, t);
1226		else
1227			count = omap2_mcspi_txrx_pio(spi, t);
1228
1229		if (count != t->len) {
1230			status = -EIO;
1231			goto out;
1232		}
1233	}
1234
1235	omap2_mcspi_set_enable(spi, 0);
1236
1237	if (mcspi->fifo_depth > 0)
1238		omap2_mcspi_set_fifo(spi, t, 0);
1239
1240out:
1241	/* Restore defaults if they were overriden */
1242	if (par_override) {
1243		par_override = 0;
1244		status = omap2_mcspi_setup_transfer(spi, NULL);
1245	}
1246
 
 
 
 
 
 
 
 
1247	omap2_mcspi_set_enable(spi, 0);
1248
1249	if (spi_get_csgpiod(spi, 0))
1250		omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1251
1252	if (mcspi->fifo_depth > 0 && t)
1253		omap2_mcspi_set_fifo(spi, t, 0);
1254
1255	return status;
1256}
1257
1258static int omap2_mcspi_prepare_message(struct spi_controller *ctlr,
1259				       struct spi_message *msg)
1260{
1261	struct omap2_mcspi	*mcspi = spi_controller_get_devdata(ctlr);
1262	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1263	struct omap2_mcspi_cs	*cs;
1264	struct spi_transfer	*tr;
1265	u8 bits_per_word;
1266
1267	/*
1268	 * The conditions are strict, it is mandatory to check each transfer of the list to see if
1269	 * multi-mode is applicable.
1270	 */
1271	mcspi->use_multi_mode = true;
1272	list_for_each_entry(tr, &msg->transfers, transfer_list) {
1273		if (!tr->bits_per_word)
1274			bits_per_word = msg->spi->bits_per_word;
1275		else
1276			bits_per_word = tr->bits_per_word;
1277
1278		/*
1279		 * Check if this transfer contains only one word;
1280		 */
1281		if (bits_per_word < 8 && tr->len == 1) {
1282			/* multi-mode is applicable, only one word (1..7 bits) */
1283		} else if (bits_per_word >= 8 && tr->len == bits_per_word / 8) {
1284			/* multi-mode is applicable, only one word (8..32 bits) */
1285		} else {
1286			/* multi-mode is not applicable: more than one word in the transfer */
1287			mcspi->use_multi_mode = false;
1288		}
1289
1290		/* Check if transfer asks to change the CS status after the transfer */
1291		if (!tr->cs_change)
1292			mcspi->use_multi_mode = false;
1293
1294		/*
1295		 * If at least one message is not compatible, switch back to single mode
1296		 *
1297		 * The bits_per_word of certain transfer can be different, but it will have no
1298		 * impact on the signal itself.
1299		 */
1300		if (!mcspi->use_multi_mode)
1301			break;
1302	}
1303
1304	omap2_mcspi_set_mode(ctlr);
1305
1306	/* In single mode only a single channel can have the FORCE bit enabled
1307	 * in its chconf0 register.
1308	 * Scan all channels and disable them except the current one.
1309	 * A FORCE can remain from a last transfer having cs_change enabled
1310	 *
1311	 * In multi mode all FORCE bits must be disabled.
1312	 */
1313	list_for_each_entry(cs, &ctx->cs, node) {
1314		if (msg->spi->controller_state == cs && !mcspi->use_multi_mode) {
1315			continue;
1316		}
1317
1318		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1319			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1320			writel_relaxed(cs->chconf0,
1321					cs->base + OMAP2_MCSPI_CHCONF0);
1322			readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1323		}
1324	}
1325
1326	return 0;
1327}
1328
1329static bool omap2_mcspi_can_dma(struct spi_controller *ctlr,
1330				struct spi_device *spi,
1331				struct spi_transfer *xfer)
1332{
1333	struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
1334	struct omap2_mcspi_dma *mcspi_dma =
1335		&mcspi->dma_channels[spi_get_chipselect(spi, 0)];
1336
1337	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1338		return false;
1339
1340	if (spi_controller_is_target(ctlr))
1341		return true;
1342
1343	ctlr->dma_rx = mcspi_dma->dma_rx;
1344	ctlr->dma_tx = mcspi_dma->dma_tx;
1345
1346	return (xfer->len >= DMA_MIN_BYTES);
1347}
1348
1349static size_t omap2_mcspi_max_xfer_size(struct spi_device *spi)
1350{
1351	struct omap2_mcspi *mcspi = spi_controller_get_devdata(spi->controller);
1352	struct omap2_mcspi_dma *mcspi_dma =
1353		&mcspi->dma_channels[spi_get_chipselect(spi, 0)];
1354
1355	if (mcspi->max_xfer_len && mcspi_dma->dma_rx)
1356		return mcspi->max_xfer_len;
1357
1358	return SIZE_MAX;
1359}
1360
1361static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1362{
1363	struct spi_controller	*ctlr = mcspi->ctlr;
1364	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1365	int			ret = 0;
1366
1367	ret = pm_runtime_resume_and_get(mcspi->dev);
1368	if (ret < 0)
 
 
1369		return ret;
 
1370
1371	mcspi_write_reg(ctlr, OMAP2_MCSPI_WAKEUPENABLE,
1372			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1373	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1374
1375	omap2_mcspi_set_mode(ctlr);
1376	pm_runtime_mark_last_busy(mcspi->dev);
1377	pm_runtime_put_autosuspend(mcspi->dev);
1378	return 0;
1379}
1380
1381static int omap_mcspi_runtime_suspend(struct device *dev)
1382{
1383	int error;
1384
1385	error = pinctrl_pm_select_idle_state(dev);
1386	if (error)
1387		dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1388
1389	return 0;
1390}
1391
1392/*
1393 * When SPI wake up from off-mode, CS is in activate state. If it was in
1394 * inactive state when driver was suspend, then force it to inactive state at
1395 * wake up.
1396 */
1397static int omap_mcspi_runtime_resume(struct device *dev)
1398{
1399	struct spi_controller *ctlr = dev_get_drvdata(dev);
1400	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1401	struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1402	struct omap2_mcspi_cs *cs;
1403	int error;
1404
1405	error = pinctrl_pm_select_default_state(dev);
1406	if (error)
1407		dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1408
1409	/* McSPI: context restore */
1410	mcspi_write_reg(ctlr, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1411	mcspi_write_reg(ctlr, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1412
1413	list_for_each_entry(cs, &ctx->cs, node) {
1414		/*
1415		 * We need to toggle CS state for OMAP take this
1416		 * change in account.
1417		 */
1418		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1419			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1420			writel_relaxed(cs->chconf0,
1421				       cs->base + OMAP2_MCSPI_CHCONF0);
1422			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1423			writel_relaxed(cs->chconf0,
1424				       cs->base + OMAP2_MCSPI_CHCONF0);
1425		} else {
1426			writel_relaxed(cs->chconf0,
1427				       cs->base + OMAP2_MCSPI_CHCONF0);
1428		}
1429	}
1430
1431	return 0;
1432}
1433
1434static struct omap2_mcspi_platform_config omap2_pdata = {
1435	.regs_offset = 0,
1436};
1437
1438static struct omap2_mcspi_platform_config omap4_pdata = {
1439	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1440};
1441
1442static struct omap2_mcspi_platform_config am654_pdata = {
1443	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1444	.max_xfer_len = SZ_4K - 1,
1445};
1446
1447static const struct of_device_id omap_mcspi_of_match[] = {
1448	{
1449		.compatible = "ti,omap2-mcspi",
1450		.data = &omap2_pdata,
1451	},
1452	{
1453		.compatible = "ti,omap4-mcspi",
1454		.data = &omap4_pdata,
1455	},
1456	{
1457		.compatible = "ti,am654-mcspi",
1458		.data = &am654_pdata,
1459	},
1460	{ },
1461};
1462MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1463
1464static int omap2_mcspi_probe(struct platform_device *pdev)
1465{
1466	struct spi_controller	*ctlr;
1467	const struct omap2_mcspi_platform_config *pdata;
1468	struct omap2_mcspi	*mcspi;
1469	struct resource		*r;
1470	int			status = 0, i;
1471	u32			regs_offset = 0;
1472	struct device_node	*node = pdev->dev.of_node;
1473	const struct of_device_id *match;
1474
1475	if (of_property_read_bool(node, "spi-slave"))
1476		ctlr = spi_alloc_target(&pdev->dev, sizeof(*mcspi));
1477	else
1478		ctlr = spi_alloc_host(&pdev->dev, sizeof(*mcspi));
1479	if (!ctlr)
1480		return -ENOMEM;
1481
1482	/* the spi->mode bits understood by this driver: */
1483	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1484	ctlr->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1485	ctlr->setup = omap2_mcspi_setup;
1486	ctlr->auto_runtime_pm = true;
1487	ctlr->prepare_message = omap2_mcspi_prepare_message;
1488	ctlr->can_dma = omap2_mcspi_can_dma;
1489	ctlr->transfer_one = omap2_mcspi_transfer_one;
1490	ctlr->set_cs = omap2_mcspi_set_cs;
1491	ctlr->cleanup = omap2_mcspi_cleanup;
1492	ctlr->target_abort = omap2_mcspi_target_abort;
1493	ctlr->dev.of_node = node;
1494	ctlr->use_gpio_descriptors = true;
 
 
1495
1496	platform_set_drvdata(pdev, ctlr);
1497
1498	mcspi = spi_controller_get_devdata(ctlr);
1499	mcspi->ctlr = ctlr;
1500
1501	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1502	if (match) {
1503		u32 num_cs = 1; /* default number of chipselect */
1504		pdata = match->data;
1505
1506		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1507		ctlr->num_chipselect = num_cs;
1508		if (of_property_read_bool(node, "ti,pindir-d0-out-d1-in"))
1509			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1510	} else {
1511		pdata = dev_get_platdata(&pdev->dev);
1512		ctlr->num_chipselect = pdata->num_cs;
1513		mcspi->pin_dir = pdata->pin_dir;
1514	}
1515	regs_offset = pdata->regs_offset;
1516	if (pdata->max_xfer_len) {
1517		mcspi->max_xfer_len = pdata->max_xfer_len;
1518		ctlr->max_transfer_size = omap2_mcspi_max_xfer_size;
1519	}
1520
1521	mcspi->base = devm_platform_get_and_ioremap_resource(pdev, 0, &r);
 
1522	if (IS_ERR(mcspi->base)) {
1523		status = PTR_ERR(mcspi->base);
1524		goto free_ctlr;
1525	}
1526	mcspi->phys = r->start + regs_offset;
1527	mcspi->base += regs_offset;
1528
1529	mcspi->dev = &pdev->dev;
1530
1531	INIT_LIST_HEAD(&mcspi->ctx.cs);
1532
1533	mcspi->dma_channels = devm_kcalloc(&pdev->dev, ctlr->num_chipselect,
1534					   sizeof(struct omap2_mcspi_dma),
1535					   GFP_KERNEL);
1536	if (mcspi->dma_channels == NULL) {
1537		status = -ENOMEM;
1538		goto free_ctlr;
1539	}
1540
1541	for (i = 0; i < ctlr->num_chipselect; i++) {
1542		sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1543		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1544
1545		status = omap2_mcspi_request_dma(mcspi,
1546						 &mcspi->dma_channels[i]);
1547		if (status == -EPROBE_DEFER)
1548			goto free_ctlr;
1549	}
1550
1551	status = platform_get_irq(pdev, 0);
1552	if (status < 0)
1553		goto free_ctlr;
 
 
 
 
1554	init_completion(&mcspi->txdone);
1555	status = devm_request_irq(&pdev->dev, status,
1556				  omap2_mcspi_irq_handler, 0, pdev->name,
1557				  mcspi);
1558	if (status) {
1559		dev_err(&pdev->dev, "Cannot request IRQ");
1560		goto free_ctlr;
1561	}
1562
1563	mcspi->ref_clk = devm_clk_get_optional_enabled(&pdev->dev, NULL);
1564	if (IS_ERR(mcspi->ref_clk)) {
1565		status = PTR_ERR(mcspi->ref_clk);
1566		dev_err_probe(&pdev->dev, status, "Failed to get ref_clk");
1567		goto free_ctlr;
1568	}
1569	if (mcspi->ref_clk)
1570		mcspi->ref_clk_hz = clk_get_rate(mcspi->ref_clk);
1571	else
1572		mcspi->ref_clk_hz = OMAP2_MCSPI_MAX_FREQ;
1573	ctlr->max_speed_hz = mcspi->ref_clk_hz;
1574	ctlr->min_speed_hz = mcspi->ref_clk_hz >> 15;
1575
1576	pm_runtime_use_autosuspend(&pdev->dev);
1577	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1578	pm_runtime_enable(&pdev->dev);
1579
1580	status = omap2_mcspi_controller_setup(mcspi);
1581	if (status < 0)
1582		goto disable_pm;
1583
1584	status = devm_spi_register_controller(&pdev->dev, ctlr);
1585	if (status < 0)
1586		goto disable_pm;
1587
1588	return status;
1589
1590disable_pm:
1591	pm_runtime_dont_use_autosuspend(&pdev->dev);
1592	pm_runtime_put_sync(&pdev->dev);
1593	pm_runtime_disable(&pdev->dev);
1594free_ctlr:
1595	omap2_mcspi_release_dma(ctlr);
1596	spi_controller_put(ctlr);
1597	return status;
1598}
1599
1600static void omap2_mcspi_remove(struct platform_device *pdev)
1601{
1602	struct spi_controller *ctlr = platform_get_drvdata(pdev);
1603	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1604
1605	omap2_mcspi_release_dma(ctlr);
1606
1607	pm_runtime_dont_use_autosuspend(mcspi->dev);
1608	pm_runtime_put_sync(mcspi->dev);
1609	pm_runtime_disable(&pdev->dev);
 
 
1610}
1611
1612/* work with hotplug and coldplug */
1613MODULE_ALIAS("platform:omap2_mcspi");
1614
1615static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1616{
1617	struct spi_controller *ctlr = dev_get_drvdata(dev);
1618	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1619	int error;
1620
1621	error = pinctrl_pm_select_sleep_state(dev);
1622	if (error)
1623		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1624			 __func__, error);
1625
1626	error = spi_controller_suspend(ctlr);
1627	if (error)
1628		dev_warn(mcspi->dev, "%s: controller suspend failed: %i\n",
1629			 __func__, error);
1630
1631	return pm_runtime_force_suspend(dev);
1632}
1633
1634static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1635{
1636	struct spi_controller *ctlr = dev_get_drvdata(dev);
1637	struct omap2_mcspi *mcspi = spi_controller_get_devdata(ctlr);
1638	int error;
1639
1640	error = spi_controller_resume(ctlr);
1641	if (error)
1642		dev_warn(mcspi->dev, "%s: controller resume failed: %i\n",
1643			 __func__, error);
1644
1645	return pm_runtime_force_resume(dev);
1646}
1647
1648static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1649	SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1650				omap2_mcspi_resume)
1651	.runtime_suspend	= omap_mcspi_runtime_suspend,
1652	.runtime_resume		= omap_mcspi_runtime_resume,
1653};
1654
1655static struct platform_driver omap2_mcspi_driver = {
1656	.driver = {
1657		.name =		"omap2_mcspi",
1658		.pm =		&omap2_mcspi_pm_ops,
1659		.of_match_table = omap_mcspi_of_match,
1660	},
1661	.probe =	omap2_mcspi_probe,
1662	.remove =	omap2_mcspi_remove,
1663};
1664
1665module_platform_driver(omap2_mcspi_driver);
1666MODULE_DESCRIPTION("OMAP2 McSPI controller driver");
1667MODULE_LICENSE("GPL");
v5.14.15
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * OMAP2 McSPI controller driver
   4 *
   5 * Copyright (C) 2005, 2006 Nokia Corporation
   6 * Author:	Samuel Ortiz <samuel.ortiz@nokia.com> and
   7 *		Juha Yrjola <juha.yrjola@nokia.com>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/interrupt.h>
  12#include <linux/module.h>
  13#include <linux/device.h>
  14#include <linux/delay.h>
  15#include <linux/dma-mapping.h>
  16#include <linux/dmaengine.h>
  17#include <linux/pinctrl/consumer.h>
  18#include <linux/platform_device.h>
  19#include <linux/err.h>
  20#include <linux/clk.h>
  21#include <linux/io.h>
  22#include <linux/slab.h>
  23#include <linux/pm_runtime.h>
  24#include <linux/of.h>
  25#include <linux/of_device.h>
  26#include <linux/gcd.h>
  27
  28#include <linux/spi/spi.h>
  29
 
 
  30#include <linux/platform_data/spi-omap2-mcspi.h>
  31
  32#define OMAP2_MCSPI_MAX_FREQ		48000000
  33#define OMAP2_MCSPI_MAX_DIVIDER		4096
  34#define OMAP2_MCSPI_MAX_FIFODEPTH	64
  35#define OMAP2_MCSPI_MAX_FIFOWCNT	0xFFFF
  36#define SPI_AUTOSUSPEND_TIMEOUT		2000
  37
  38#define OMAP2_MCSPI_REVISION		0x00
  39#define OMAP2_MCSPI_SYSSTATUS		0x14
  40#define OMAP2_MCSPI_IRQSTATUS		0x18
  41#define OMAP2_MCSPI_IRQENABLE		0x1c
  42#define OMAP2_MCSPI_WAKEUPENABLE	0x20
  43#define OMAP2_MCSPI_SYST		0x24
  44#define OMAP2_MCSPI_MODULCTRL		0x28
  45#define OMAP2_MCSPI_XFERLEVEL		0x7c
  46
  47/* per-channel banks, 0x14 bytes each, first is: */
  48#define OMAP2_MCSPI_CHCONF0		0x2c
  49#define OMAP2_MCSPI_CHSTAT0		0x30
  50#define OMAP2_MCSPI_CHCTRL0		0x34
  51#define OMAP2_MCSPI_TX0			0x38
  52#define OMAP2_MCSPI_RX0			0x3c
  53
  54/* per-register bitmasks: */
  55#define OMAP2_MCSPI_IRQSTATUS_EOW	BIT(17)
  56
  57#define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
  58#define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
  59#define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
  60
  61#define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
  62#define OMAP2_MCSPI_CHCONF_POL		BIT(1)
  63#define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
  64#define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
  65#define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
  66#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
  67#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
  68#define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
  69#define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
  70#define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
  71#define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
  72#define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
  73#define OMAP2_MCSPI_CHCONF_IS		BIT(18)
  74#define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
  75#define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
  76#define OMAP2_MCSPI_CHCONF_FFET		BIT(27)
  77#define OMAP2_MCSPI_CHCONF_FFER		BIT(28)
  78#define OMAP2_MCSPI_CHCONF_CLKG		BIT(29)
  79
  80#define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
  81#define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
  82#define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
  83#define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
  84
  85#define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
  86#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK	(0xff << 8)
  87
  88#define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
  89
  90/* We have 2 DMA channels per CS, one for RX and one for TX */
  91struct omap2_mcspi_dma {
  92	struct dma_chan *dma_tx;
  93	struct dma_chan *dma_rx;
  94
  95	struct completion dma_tx_completion;
  96	struct completion dma_rx_completion;
  97
  98	char dma_rx_ch_name[14];
  99	char dma_tx_ch_name[14];
 100};
 101
 102/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
 103 * cache operations; better heuristics consider wordsize and bitrate.
 104 */
 105#define DMA_MIN_BYTES			160
 106
 107
 108/*
 109 * Used for context save and restore, structure members to be updated whenever
 110 * corresponding registers are modified.
 111 */
 112struct omap2_mcspi_regs {
 113	u32 modulctrl;
 114	u32 wakeupenable;
 115	struct list_head cs;
 116};
 117
 118struct omap2_mcspi {
 119	struct completion	txdone;
 120	struct spi_master	*master;
 121	/* Virtual base address of the controller */
 122	void __iomem		*base;
 123	unsigned long		phys;
 124	/* SPI1 has 4 channels, while SPI2 has 2 */
 125	struct omap2_mcspi_dma	*dma_channels;
 126	struct device		*dev;
 127	struct omap2_mcspi_regs ctx;
 
 128	int			fifo_depth;
 129	bool			slave_aborted;
 130	unsigned int		pin_dir:1;
 131	size_t			max_xfer_len;
 
 
 132};
 133
 134struct omap2_mcspi_cs {
 135	void __iomem		*base;
 136	unsigned long		phys;
 137	int			word_len;
 138	u16			mode;
 139	struct list_head	node;
 140	/* Context save and restore shadow register */
 141	u32			chconf0, chctrl0;
 142};
 143
 144static inline void mcspi_write_reg(struct spi_master *master,
 145		int idx, u32 val)
 146{
 147	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 148
 149	writel_relaxed(val, mcspi->base + idx);
 150}
 151
 152static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
 153{
 154	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
 155
 156	return readl_relaxed(mcspi->base + idx);
 157}
 158
 159static inline void mcspi_write_cs_reg(const struct spi_device *spi,
 160		int idx, u32 val)
 161{
 162	struct omap2_mcspi_cs	*cs = spi->controller_state;
 163
 164	writel_relaxed(val, cs->base +  idx);
 165}
 166
 167static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
 168{
 169	struct omap2_mcspi_cs	*cs = spi->controller_state;
 170
 171	return readl_relaxed(cs->base + idx);
 172}
 173
 174static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
 175{
 176	struct omap2_mcspi_cs *cs = spi->controller_state;
 177
 178	return cs->chconf0;
 179}
 180
 181static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
 182{
 183	struct omap2_mcspi_cs *cs = spi->controller_state;
 184
 185	cs->chconf0 = val;
 186	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
 187	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
 188}
 189
 190static inline int mcspi_bytes_per_word(int word_len)
 191{
 192	if (word_len <= 8)
 193		return 1;
 194	else if (word_len <= 16)
 195		return 2;
 196	else /* word_len <= 32 */
 197		return 4;
 198}
 199
 200static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
 201		int is_read, int enable)
 202{
 203	u32 l, rw;
 204
 205	l = mcspi_cached_chconf0(spi);
 206
 207	if (is_read) /* 1 is read, 0 write */
 208		rw = OMAP2_MCSPI_CHCONF_DMAR;
 209	else
 210		rw = OMAP2_MCSPI_CHCONF_DMAW;
 211
 212	if (enable)
 213		l |= rw;
 214	else
 215		l &= ~rw;
 216
 217	mcspi_write_chconf0(spi, l);
 218}
 219
 220static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
 221{
 222	struct omap2_mcspi_cs *cs = spi->controller_state;
 223	u32 l;
 224
 225	l = cs->chctrl0;
 226	if (enable)
 227		l |= OMAP2_MCSPI_CHCTRL_EN;
 228	else
 229		l &= ~OMAP2_MCSPI_CHCTRL_EN;
 230	cs->chctrl0 = l;
 231	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 232	/* Flash post-writes */
 233	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
 234}
 235
 236static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
 237{
 238	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 239	u32 l;
 240
 241	/* The controller handles the inverted chip selects
 242	 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
 243	 * the inversion from the core spi_set_cs function.
 244	 */
 245	if (spi->mode & SPI_CS_HIGH)
 246		enable = !enable;
 247
 248	if (spi->controller_state) {
 249		int err = pm_runtime_get_sync(mcspi->dev);
 250		if (err < 0) {
 251			pm_runtime_put_noidle(mcspi->dev);
 252			dev_err(mcspi->dev, "failed to get sync: %d\n", err);
 253			return;
 254		}
 255
 256		l = mcspi_cached_chconf0(spi);
 257
 258		if (enable)
 
 259			l &= ~OMAP2_MCSPI_CHCONF_FORCE;
 260		else
 261			l |= OMAP2_MCSPI_CHCONF_FORCE;
 
 
 
 
 262
 263		mcspi_write_chconf0(spi, l);
 264
 265		pm_runtime_mark_last_busy(mcspi->dev);
 266		pm_runtime_put_autosuspend(mcspi->dev);
 267	}
 268}
 269
 270static void omap2_mcspi_set_mode(struct spi_master *master)
 271{
 272	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
 273	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
 274	u32 l;
 275
 276	/*
 277	 * Choose master or slave mode
 278	 */
 279	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
 280	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST);
 281	if (spi_controller_is_slave(master)) {
 282		l |= (OMAP2_MCSPI_MODULCTRL_MS);
 283	} else {
 284		l &= ~(OMAP2_MCSPI_MODULCTRL_MS);
 285		l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
 
 
 
 
 
 286	}
 287	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
 288
 289	ctx->modulctrl = l;
 290}
 291
 292static void omap2_mcspi_set_fifo(const struct spi_device *spi,
 293				struct spi_transfer *t, int enable)
 294{
 295	struct spi_master *master = spi->master;
 296	struct omap2_mcspi_cs *cs = spi->controller_state;
 297	struct omap2_mcspi *mcspi;
 298	unsigned int wcnt;
 299	int max_fifo_depth, bytes_per_word;
 300	u32 chconf, xferlevel;
 301
 302	mcspi = spi_master_get_devdata(master);
 303
 304	chconf = mcspi_cached_chconf0(spi);
 305	if (enable) {
 306		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
 307		if (t->len % bytes_per_word != 0)
 308			goto disable_fifo;
 309
 310		if (t->rx_buf != NULL && t->tx_buf != NULL)
 311			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
 312		else
 313			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
 314
 315		wcnt = t->len / bytes_per_word;
 316		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
 317			goto disable_fifo;
 318
 319		xferlevel = wcnt << 16;
 320		if (t->rx_buf != NULL) {
 321			chconf |= OMAP2_MCSPI_CHCONF_FFER;
 322			xferlevel |= (bytes_per_word - 1) << 8;
 323		}
 324
 325		if (t->tx_buf != NULL) {
 326			chconf |= OMAP2_MCSPI_CHCONF_FFET;
 327			xferlevel |= bytes_per_word - 1;
 328		}
 329
 330		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
 331		mcspi_write_chconf0(spi, chconf);
 332		mcspi->fifo_depth = max_fifo_depth;
 333
 334		return;
 335	}
 336
 337disable_fifo:
 338	if (t->rx_buf != NULL)
 339		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
 340
 341	if (t->tx_buf != NULL)
 342		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
 343
 344	mcspi_write_chconf0(spi, chconf);
 345	mcspi->fifo_depth = 0;
 346}
 347
 348static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
 349{
 350	unsigned long timeout;
 351
 352	timeout = jiffies + msecs_to_jiffies(1000);
 353	while (!(readl_relaxed(reg) & bit)) {
 354		if (time_after(jiffies, timeout)) {
 355			if (!(readl_relaxed(reg) & bit))
 356				return -ETIMEDOUT;
 357			else
 358				return 0;
 359		}
 360		cpu_relax();
 361	}
 362	return 0;
 363}
 364
 365static int mcspi_wait_for_completion(struct  omap2_mcspi *mcspi,
 366				     struct completion *x)
 367{
 368	if (spi_controller_is_slave(mcspi->master)) {
 369		if (wait_for_completion_interruptible(x) ||
 370		    mcspi->slave_aborted)
 371			return -EINTR;
 372	} else {
 373		wait_for_completion(x);
 374	}
 375
 376	return 0;
 377}
 378
 379static void omap2_mcspi_rx_callback(void *data)
 380{
 381	struct spi_device *spi = data;
 382	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 383	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 384
 385	/* We must disable the DMA RX request */
 386	omap2_mcspi_set_dma_req(spi, 1, 0);
 387
 388	complete(&mcspi_dma->dma_rx_completion);
 389}
 390
 391static void omap2_mcspi_tx_callback(void *data)
 392{
 393	struct spi_device *spi = data;
 394	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
 395	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 396
 397	/* We must disable the DMA TX request */
 398	omap2_mcspi_set_dma_req(spi, 0, 0);
 399
 400	complete(&mcspi_dma->dma_tx_completion);
 401}
 402
 403static void omap2_mcspi_tx_dma(struct spi_device *spi,
 404				struct spi_transfer *xfer,
 405				struct dma_slave_config cfg)
 406{
 407	struct omap2_mcspi	*mcspi;
 408	struct omap2_mcspi_dma  *mcspi_dma;
 409	struct dma_async_tx_descriptor *tx;
 410
 411	mcspi = spi_master_get_devdata(spi->master);
 412	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 413
 414	dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
 415
 416	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
 417				     xfer->tx_sg.nents,
 418				     DMA_MEM_TO_DEV,
 419				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 420	if (tx) {
 421		tx->callback = omap2_mcspi_tx_callback;
 422		tx->callback_param = spi;
 423		dmaengine_submit(tx);
 424	} else {
 425		/* FIXME: fall back to PIO? */
 426	}
 427	dma_async_issue_pending(mcspi_dma->dma_tx);
 428	omap2_mcspi_set_dma_req(spi, 0, 1);
 429}
 430
 431static unsigned
 432omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 433				struct dma_slave_config cfg,
 434				unsigned es)
 435{
 436	struct omap2_mcspi	*mcspi;
 437	struct omap2_mcspi_dma  *mcspi_dma;
 438	unsigned int		count, transfer_reduction = 0;
 439	struct scatterlist	*sg_out[2];
 440	int			nb_sizes = 0, out_mapped_nents[2], ret, x;
 441	size_t			sizes[2];
 442	u32			l;
 443	int			elements = 0;
 444	int			word_len, element_count;
 445	struct omap2_mcspi_cs	*cs = spi->controller_state;
 446	void __iomem		*chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 447	struct dma_async_tx_descriptor *tx;
 448
 449	mcspi = spi_master_get_devdata(spi->master);
 450	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 451	count = xfer->len;
 452
 453	/*
 454	 *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
 455	 *  it mentions reducing DMA transfer length by one element in master
 456	 *  normal mode.
 457	 */
 458	if (mcspi->fifo_depth == 0)
 459		transfer_reduction = es;
 460
 461	word_len = cs->word_len;
 462	l = mcspi_cached_chconf0(spi);
 463
 464	if (word_len <= 8)
 465		element_count = count;
 466	else if (word_len <= 16)
 467		element_count = count >> 1;
 468	else /* word_len <= 32 */
 469		element_count = count >> 2;
 470
 471
 472	dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
 473
 474	/*
 475	 *  Reduce DMA transfer length by one more if McSPI is
 476	 *  configured in turbo mode.
 477	 */
 478	if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
 479		transfer_reduction += es;
 480
 481	if (transfer_reduction) {
 482		/* Split sgl into two. The second sgl won't be used. */
 483		sizes[0] = count - transfer_reduction;
 484		sizes[1] = transfer_reduction;
 485		nb_sizes = 2;
 486	} else {
 487		/*
 488		 * Don't bother splitting the sgl. This essentially
 489		 * clones the original sgl.
 490		 */
 491		sizes[0] = count;
 492		nb_sizes = 1;
 493	}
 494
 495	ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents, 0, nb_sizes,
 496		       sizes, sg_out, out_mapped_nents, GFP_KERNEL);
 497
 498	if (ret < 0) {
 499		dev_err(&spi->dev, "sg_split failed\n");
 500		return 0;
 501	}
 502
 503	tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, sg_out[0],
 504				     out_mapped_nents[0], DMA_DEV_TO_MEM,
 505				     DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 506	if (tx) {
 507		tx->callback = omap2_mcspi_rx_callback;
 508		tx->callback_param = spi;
 509		dmaengine_submit(tx);
 510	} else {
 511		/* FIXME: fall back to PIO? */
 512	}
 513
 514	dma_async_issue_pending(mcspi_dma->dma_rx);
 515	omap2_mcspi_set_dma_req(spi, 1, 1);
 516
 517	ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_rx_completion);
 518	if (ret || mcspi->slave_aborted) {
 519		dmaengine_terminate_sync(mcspi_dma->dma_rx);
 520		omap2_mcspi_set_dma_req(spi, 1, 0);
 521		return 0;
 522	}
 523
 524	for (x = 0; x < nb_sizes; x++)
 525		kfree(sg_out[x]);
 526
 527	if (mcspi->fifo_depth > 0)
 528		return count;
 529
 530	/*
 531	 *  Due to the DMA transfer length reduction the missing bytes must
 532	 *  be read manually to receive all of the expected data.
 533	 */
 534	omap2_mcspi_set_enable(spi, 0);
 535
 536	elements = element_count - 1;
 537
 538	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
 539		elements--;
 540
 541		if (!mcspi_wait_for_reg_bit(chstat_reg,
 542					    OMAP2_MCSPI_CHSTAT_RXS)) {
 543			u32 w;
 544
 545			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 546			if (word_len <= 8)
 547				((u8 *)xfer->rx_buf)[elements++] = w;
 548			else if (word_len <= 16)
 549				((u16 *)xfer->rx_buf)[elements++] = w;
 550			else /* word_len <= 32 */
 551				((u32 *)xfer->rx_buf)[elements++] = w;
 552		} else {
 553			int bytes_per_word = mcspi_bytes_per_word(word_len);
 554			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
 555			count -= (bytes_per_word << 1);
 556			omap2_mcspi_set_enable(spi, 1);
 557			return count;
 558		}
 559	}
 560	if (!mcspi_wait_for_reg_bit(chstat_reg, OMAP2_MCSPI_CHSTAT_RXS)) {
 561		u32 w;
 562
 563		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
 564		if (word_len <= 8)
 565			((u8 *)xfer->rx_buf)[elements] = w;
 566		else if (word_len <= 16)
 567			((u16 *)xfer->rx_buf)[elements] = w;
 568		else /* word_len <= 32 */
 569			((u32 *)xfer->rx_buf)[elements] = w;
 570	} else {
 571		dev_err(&spi->dev, "DMA RX last word empty\n");
 572		count -= mcspi_bytes_per_word(word_len);
 573	}
 574	omap2_mcspi_set_enable(spi, 1);
 575	return count;
 576}
 577
 578static unsigned
 579omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
 580{
 581	struct omap2_mcspi	*mcspi;
 582	struct omap2_mcspi_cs	*cs = spi->controller_state;
 583	struct omap2_mcspi_dma  *mcspi_dma;
 584	unsigned int		count;
 585	u8			*rx;
 586	const u8		*tx;
 587	struct dma_slave_config	cfg;
 588	enum dma_slave_buswidth width;
 589	unsigned es;
 590	void __iomem		*chstat_reg;
 591	void __iomem            *irqstat_reg;
 592	int			wait_res;
 593
 594	mcspi = spi_master_get_devdata(spi->master);
 595	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
 596
 597	if (cs->word_len <= 8) {
 598		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
 599		es = 1;
 600	} else if (cs->word_len <= 16) {
 601		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
 602		es = 2;
 603	} else {
 604		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 605		es = 4;
 606	}
 607
 608	count = xfer->len;
 609
 610	memset(&cfg, 0, sizeof(cfg));
 611	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
 612	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
 613	cfg.src_addr_width = width;
 614	cfg.dst_addr_width = width;
 615	cfg.src_maxburst = 1;
 616	cfg.dst_maxburst = 1;
 617
 618	rx = xfer->rx_buf;
 619	tx = xfer->tx_buf;
 620
 621	mcspi->slave_aborted = false;
 622	reinit_completion(&mcspi_dma->dma_tx_completion);
 623	reinit_completion(&mcspi_dma->dma_rx_completion);
 624	reinit_completion(&mcspi->txdone);
 625	if (tx) {
 626		/* Enable EOW IRQ to know end of tx in slave mode */
 627		if (spi_controller_is_slave(spi->master))
 628			mcspi_write_reg(spi->master,
 629					OMAP2_MCSPI_IRQENABLE,
 630					OMAP2_MCSPI_IRQSTATUS_EOW);
 631		omap2_mcspi_tx_dma(spi, xfer, cfg);
 632	}
 633
 634	if (rx != NULL)
 635		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
 636
 637	if (tx != NULL) {
 638		int ret;
 639
 640		ret = mcspi_wait_for_completion(mcspi, &mcspi_dma->dma_tx_completion);
 641		if (ret || mcspi->slave_aborted) {
 642			dmaengine_terminate_sync(mcspi_dma->dma_tx);
 643			omap2_mcspi_set_dma_req(spi, 0, 0);
 644			return 0;
 645		}
 646
 647		if (spi_controller_is_slave(mcspi->master)) {
 648			ret = mcspi_wait_for_completion(mcspi, &mcspi->txdone);
 649			if (ret || mcspi->slave_aborted)
 650				return 0;
 651		}
 652
 653		if (mcspi->fifo_depth > 0) {
 654			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
 655
 656			if (mcspi_wait_for_reg_bit(irqstat_reg,
 657						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
 658				dev_err(&spi->dev, "EOW timed out\n");
 659
 660			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
 661					OMAP2_MCSPI_IRQSTATUS_EOW);
 662		}
 663
 664		/* for TX_ONLY mode, be sure all words have shifted out */
 665		if (rx == NULL) {
 666			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
 667			if (mcspi->fifo_depth > 0) {
 668				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 669						OMAP2_MCSPI_CHSTAT_TXFFE);
 670				if (wait_res < 0)
 671					dev_err(&spi->dev, "TXFFE timed out\n");
 672			} else {
 673				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
 674						OMAP2_MCSPI_CHSTAT_TXS);
 675				if (wait_res < 0)
 676					dev_err(&spi->dev, "TXS timed out\n");
 677			}
 678			if (wait_res >= 0 &&
 679				(mcspi_wait_for_reg_bit(chstat_reg,
 680					OMAP2_MCSPI_CHSTAT_EOT) < 0))
 681				dev_err(&spi->dev, "EOT timed out\n");
 682		}
 683	}
 684	return count;
 685}
 686
 687static unsigned
 688omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
 689{
 690	struct omap2_mcspi_cs	*cs = spi->controller_state;
 691	unsigned int		count, c;
 692	u32			l;
 693	void __iomem		*base = cs->base;
 694	void __iomem		*tx_reg;
 695	void __iomem		*rx_reg;
 696	void __iomem		*chstat_reg;
 697	int			word_len;
 698
 699	count = xfer->len;
 700	c = count;
 701	word_len = cs->word_len;
 702
 703	l = mcspi_cached_chconf0(spi);
 704
 705	/* We store the pre-calculated register addresses on stack to speed
 706	 * up the transfer loop. */
 707	tx_reg		= base + OMAP2_MCSPI_TX0;
 708	rx_reg		= base + OMAP2_MCSPI_RX0;
 709	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
 710
 711	if (c < (word_len>>3))
 712		return 0;
 713
 714	if (word_len <= 8) {
 715		u8		*rx;
 716		const u8	*tx;
 717
 718		rx = xfer->rx_buf;
 719		tx = xfer->tx_buf;
 720
 721		do {
 722			c -= 1;
 723			if (tx != NULL) {
 724				if (mcspi_wait_for_reg_bit(chstat_reg,
 725						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 726					dev_err(&spi->dev, "TXS timed out\n");
 727					goto out;
 728				}
 729				dev_vdbg(&spi->dev, "write-%d %02x\n",
 730						word_len, *tx);
 731				writel_relaxed(*tx++, tx_reg);
 732			}
 733			if (rx != NULL) {
 734				if (mcspi_wait_for_reg_bit(chstat_reg,
 735						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 736					dev_err(&spi->dev, "RXS timed out\n");
 737					goto out;
 738				}
 739
 740				if (c == 1 && tx == NULL &&
 741				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 742					omap2_mcspi_set_enable(spi, 0);
 743					*rx++ = readl_relaxed(rx_reg);
 744					dev_vdbg(&spi->dev, "read-%d %02x\n",
 745						    word_len, *(rx - 1));
 746					if (mcspi_wait_for_reg_bit(chstat_reg,
 747						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 748						dev_err(&spi->dev,
 749							"RXS timed out\n");
 750						goto out;
 751					}
 752					c = 0;
 753				} else if (c == 0 && tx == NULL) {
 754					omap2_mcspi_set_enable(spi, 0);
 755				}
 756
 757				*rx++ = readl_relaxed(rx_reg);
 758				dev_vdbg(&spi->dev, "read-%d %02x\n",
 759						word_len, *(rx - 1));
 760			}
 
 
 761		} while (c);
 762	} else if (word_len <= 16) {
 763		u16		*rx;
 764		const u16	*tx;
 765
 766		rx = xfer->rx_buf;
 767		tx = xfer->tx_buf;
 768		do {
 769			c -= 2;
 770			if (tx != NULL) {
 771				if (mcspi_wait_for_reg_bit(chstat_reg,
 772						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 773					dev_err(&spi->dev, "TXS timed out\n");
 774					goto out;
 775				}
 776				dev_vdbg(&spi->dev, "write-%d %04x\n",
 777						word_len, *tx);
 778				writel_relaxed(*tx++, tx_reg);
 779			}
 780			if (rx != NULL) {
 781				if (mcspi_wait_for_reg_bit(chstat_reg,
 782						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 783					dev_err(&spi->dev, "RXS timed out\n");
 784					goto out;
 785				}
 786
 787				if (c == 2 && tx == NULL &&
 788				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 789					omap2_mcspi_set_enable(spi, 0);
 790					*rx++ = readl_relaxed(rx_reg);
 791					dev_vdbg(&spi->dev, "read-%d %04x\n",
 792						    word_len, *(rx - 1));
 793					if (mcspi_wait_for_reg_bit(chstat_reg,
 794						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 795						dev_err(&spi->dev,
 796							"RXS timed out\n");
 797						goto out;
 798					}
 799					c = 0;
 800				} else if (c == 0 && tx == NULL) {
 801					omap2_mcspi_set_enable(spi, 0);
 802				}
 803
 804				*rx++ = readl_relaxed(rx_reg);
 805				dev_vdbg(&spi->dev, "read-%d %04x\n",
 806						word_len, *(rx - 1));
 807			}
 
 
 808		} while (c >= 2);
 809	} else if (word_len <= 32) {
 810		u32		*rx;
 811		const u32	*tx;
 812
 813		rx = xfer->rx_buf;
 814		tx = xfer->tx_buf;
 815		do {
 816			c -= 4;
 817			if (tx != NULL) {
 818				if (mcspi_wait_for_reg_bit(chstat_reg,
 819						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 820					dev_err(&spi->dev, "TXS timed out\n");
 821					goto out;
 822				}
 823				dev_vdbg(&spi->dev, "write-%d %08x\n",
 824						word_len, *tx);
 825				writel_relaxed(*tx++, tx_reg);
 826			}
 827			if (rx != NULL) {
 828				if (mcspi_wait_for_reg_bit(chstat_reg,
 829						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 830					dev_err(&spi->dev, "RXS timed out\n");
 831					goto out;
 832				}
 833
 834				if (c == 4 && tx == NULL &&
 835				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
 836					omap2_mcspi_set_enable(spi, 0);
 837					*rx++ = readl_relaxed(rx_reg);
 838					dev_vdbg(&spi->dev, "read-%d %08x\n",
 839						    word_len, *(rx - 1));
 840					if (mcspi_wait_for_reg_bit(chstat_reg,
 841						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
 842						dev_err(&spi->dev,
 843							"RXS timed out\n");
 844						goto out;
 845					}
 846					c = 0;
 847				} else if (c == 0 && tx == NULL) {
 848					omap2_mcspi_set_enable(spi, 0);
 849				}
 850
 851				*rx++ = readl_relaxed(rx_reg);
 852				dev_vdbg(&spi->dev, "read-%d %08x\n",
 853						word_len, *(rx - 1));
 854			}
 
 
 855		} while (c >= 4);
 856	}
 857
 858	/* for TX_ONLY mode, be sure all words have shifted out */
 859	if (xfer->rx_buf == NULL) {
 860		if (mcspi_wait_for_reg_bit(chstat_reg,
 861				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
 862			dev_err(&spi->dev, "TXS timed out\n");
 863		} else if (mcspi_wait_for_reg_bit(chstat_reg,
 864				OMAP2_MCSPI_CHSTAT_EOT) < 0)
 865			dev_err(&spi->dev, "EOT timed out\n");
 866
 867		/* disable chan to purge rx datas received in TX_ONLY transfer,
 868		 * otherwise these rx datas will affect the direct following
 869		 * RX_ONLY transfer.
 870		 */
 871		omap2_mcspi_set_enable(spi, 0);
 872	}
 873out:
 874	omap2_mcspi_set_enable(spi, 1);
 875	return count - c;
 876}
 877
 878static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
 879{
 880	u32 div;
 881
 882	for (div = 0; div < 15; div++)
 883		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
 884			return div;
 885
 886	return 15;
 887}
 888
 889/* called only when no transfer is active to this device */
 890static int omap2_mcspi_setup_transfer(struct spi_device *spi,
 891		struct spi_transfer *t)
 892{
 893	struct omap2_mcspi_cs *cs = spi->controller_state;
 894	struct omap2_mcspi *mcspi;
 895	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
 896	u8 word_len = spi->bits_per_word;
 897	u32 speed_hz = spi->max_speed_hz;
 898
 899	mcspi = spi_master_get_devdata(spi->master);
 900
 901	if (t != NULL && t->bits_per_word)
 902		word_len = t->bits_per_word;
 903
 904	cs->word_len = word_len;
 905
 906	if (t && t->speed_hz)
 907		speed_hz = t->speed_hz;
 908
 909	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
 910	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
 911		clkd = omap2_mcspi_calc_divisor(speed_hz);
 912		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
 
 913		clkg = 0;
 914	} else {
 915		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
 916		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
 917		clkd = (div - 1) & 0xf;
 918		extclk = (div - 1) >> 4;
 919		clkg = OMAP2_MCSPI_CHCONF_CLKG;
 920	}
 921
 922	l = mcspi_cached_chconf0(spi);
 923
 924	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
 925	 * REVISIT: this controller could support SPI_3WIRE mode.
 926	 */
 927	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
 928		l &= ~OMAP2_MCSPI_CHCONF_IS;
 929		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
 930		l |= OMAP2_MCSPI_CHCONF_DPE0;
 931	} else {
 932		l |= OMAP2_MCSPI_CHCONF_IS;
 933		l |= OMAP2_MCSPI_CHCONF_DPE1;
 934		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
 935	}
 936
 937	/* wordlength */
 938	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
 939	l |= (word_len - 1) << 7;
 940
 941	/* set chipselect polarity; manage with FORCE */
 942	if (!(spi->mode & SPI_CS_HIGH))
 943		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
 944	else
 945		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
 946
 947	/* set clock divisor */
 948	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
 949	l |= clkd << 2;
 950
 951	/* set clock granularity */
 952	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
 953	l |= clkg;
 954	if (clkg) {
 955		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
 956		cs->chctrl0 |= extclk << 8;
 957		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
 958	}
 959
 960	/* set SPI mode 0..3 */
 961	if (spi->mode & SPI_CPOL)
 962		l |= OMAP2_MCSPI_CHCONF_POL;
 963	else
 964		l &= ~OMAP2_MCSPI_CHCONF_POL;
 965	if (spi->mode & SPI_CPHA)
 966		l |= OMAP2_MCSPI_CHCONF_PHA;
 967	else
 968		l &= ~OMAP2_MCSPI_CHCONF_PHA;
 969
 970	mcspi_write_chconf0(spi, l);
 971
 972	cs->mode = spi->mode;
 973
 974	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
 975			speed_hz,
 976			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
 977			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
 978
 979	return 0;
 980}
 981
 982/*
 983 * Note that we currently allow DMA only if we get a channel
 984 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
 985 */
 986static int omap2_mcspi_request_dma(struct omap2_mcspi *mcspi,
 987				   struct omap2_mcspi_dma *mcspi_dma)
 988{
 989	int ret = 0;
 990
 991	mcspi_dma->dma_rx = dma_request_chan(mcspi->dev,
 992					     mcspi_dma->dma_rx_ch_name);
 993	if (IS_ERR(mcspi_dma->dma_rx)) {
 994		ret = PTR_ERR(mcspi_dma->dma_rx);
 995		mcspi_dma->dma_rx = NULL;
 996		goto no_dma;
 997	}
 998
 999	mcspi_dma->dma_tx = dma_request_chan(mcspi->dev,
1000					     mcspi_dma->dma_tx_ch_name);
1001	if (IS_ERR(mcspi_dma->dma_tx)) {
1002		ret = PTR_ERR(mcspi_dma->dma_tx);
1003		mcspi_dma->dma_tx = NULL;
1004		dma_release_channel(mcspi_dma->dma_rx);
1005		mcspi_dma->dma_rx = NULL;
1006	}
1007
1008	init_completion(&mcspi_dma->dma_rx_completion);
1009	init_completion(&mcspi_dma->dma_tx_completion);
1010
1011no_dma:
1012	return ret;
1013}
1014
1015static void omap2_mcspi_release_dma(struct spi_master *master)
1016{
1017	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1018	struct omap2_mcspi_dma	*mcspi_dma;
1019	int i;
1020
1021	for (i = 0; i < master->num_chipselect; i++) {
1022		mcspi_dma = &mcspi->dma_channels[i];
1023
1024		if (mcspi_dma->dma_rx) {
1025			dma_release_channel(mcspi_dma->dma_rx);
1026			mcspi_dma->dma_rx = NULL;
1027		}
1028		if (mcspi_dma->dma_tx) {
1029			dma_release_channel(mcspi_dma->dma_tx);
1030			mcspi_dma->dma_tx = NULL;
1031		}
1032	}
1033}
1034
1035static void omap2_mcspi_cleanup(struct spi_device *spi)
1036{
1037	struct omap2_mcspi_cs	*cs;
1038
1039	if (spi->controller_state) {
1040		/* Unlink controller state from context save list */
1041		cs = spi->controller_state;
1042		list_del(&cs->node);
1043
1044		kfree(cs);
1045	}
1046}
1047
1048static int omap2_mcspi_setup(struct spi_device *spi)
1049{
1050	bool			initial_setup = false;
1051	int			ret;
1052	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
1053	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1054	struct omap2_mcspi_cs	*cs = spi->controller_state;
1055
1056	if (!cs) {
1057		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
1058		if (!cs)
1059			return -ENOMEM;
1060		cs->base = mcspi->base + spi->chip_select * 0x14;
1061		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1062		cs->mode = 0;
1063		cs->chconf0 = 0;
1064		cs->chctrl0 = 0;
1065		spi->controller_state = cs;
1066		/* Link this to context save list */
1067		list_add_tail(&cs->node, &ctx->cs);
1068		initial_setup = true;
1069	}
1070
1071	ret = pm_runtime_get_sync(mcspi->dev);
1072	if (ret < 0) {
1073		pm_runtime_put_noidle(mcspi->dev);
1074		if (initial_setup)
1075			omap2_mcspi_cleanup(spi);
1076
1077		return ret;
1078	}
1079
1080	ret = omap2_mcspi_setup_transfer(spi, NULL);
1081	if (ret && initial_setup)
1082		omap2_mcspi_cleanup(spi);
1083
1084	pm_runtime_mark_last_busy(mcspi->dev);
1085	pm_runtime_put_autosuspend(mcspi->dev);
1086
1087	return ret;
1088}
1089
1090static irqreturn_t omap2_mcspi_irq_handler(int irq, void *data)
1091{
1092	struct omap2_mcspi *mcspi = data;
1093	u32 irqstat;
1094
1095	irqstat	= mcspi_read_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS);
1096	if (!irqstat)
1097		return IRQ_NONE;
1098
1099	/* Disable IRQ and wakeup slave xfer task */
1100	mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQENABLE, 0);
1101	if (irqstat & OMAP2_MCSPI_IRQSTATUS_EOW)
1102		complete(&mcspi->txdone);
1103
1104	return IRQ_HANDLED;
1105}
1106
1107static int omap2_mcspi_slave_abort(struct spi_master *master)
1108{
1109	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1110	struct omap2_mcspi_dma *mcspi_dma = mcspi->dma_channels;
1111
1112	mcspi->slave_aborted = true;
1113	complete(&mcspi_dma->dma_rx_completion);
1114	complete(&mcspi_dma->dma_tx_completion);
1115	complete(&mcspi->txdone);
1116
1117	return 0;
1118}
1119
1120static int omap2_mcspi_transfer_one(struct spi_master *master,
1121				    struct spi_device *spi,
1122				    struct spi_transfer *t)
1123{
1124
1125	/* We only enable one channel at a time -- the one whose message is
1126	 * -- although this controller would gladly
1127	 * arbitrate among multiple channels.  This corresponds to "single
1128	 * channel" master mode.  As a side effect, we need to manage the
1129	 * chipselect with the FORCE bit ... CS != channel enable.
1130	 */
1131
1132	struct omap2_mcspi		*mcspi;
1133	struct omap2_mcspi_dma		*mcspi_dma;
1134	struct omap2_mcspi_cs		*cs;
1135	struct omap2_mcspi_device_config *cd;
1136	int				par_override = 0;
1137	int				status = 0;
1138	u32				chconf;
1139
1140	mcspi = spi_master_get_devdata(master);
1141	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1142	cs = spi->controller_state;
1143	cd = spi->controller_data;
1144
1145	/*
1146	 * The slave driver could have changed spi->mode in which case
1147	 * it will be different from cs->mode (the current hardware setup).
1148	 * If so, set par_override (even though its not a parity issue) so
1149	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1150	 * with the correct mode on the first iteration of the loop below.
1151	 */
1152	if (spi->mode != cs->mode)
1153		par_override = 1;
1154
1155	omap2_mcspi_set_enable(spi, 0);
1156
1157	if (spi->cs_gpiod)
1158		omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1159
1160	if (par_override ||
1161	    (t->speed_hz != spi->max_speed_hz) ||
1162	    (t->bits_per_word != spi->bits_per_word)) {
1163		par_override = 1;
1164		status = omap2_mcspi_setup_transfer(spi, t);
1165		if (status < 0)
1166			goto out;
1167		if (t->speed_hz == spi->max_speed_hz &&
1168		    t->bits_per_word == spi->bits_per_word)
1169			par_override = 0;
1170	}
1171	if (cd && cd->cs_per_word) {
1172		chconf = mcspi->ctx.modulctrl;
1173		chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1174		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1175		mcspi->ctx.modulctrl =
1176			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1177	}
1178
1179	chconf = mcspi_cached_chconf0(spi);
1180	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1181	chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1182
1183	if (t->tx_buf == NULL)
1184		chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1185	else if (t->rx_buf == NULL)
1186		chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1187
1188	if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1189		/* Turbo mode is for more than one word */
1190		if (t->len > ((cs->word_len + 7) >> 3))
1191			chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1192	}
1193
1194	mcspi_write_chconf0(spi, chconf);
1195
1196	if (t->len) {
1197		unsigned	count;
1198
1199		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1200		    master->cur_msg_mapped &&
1201		    master->can_dma(master, spi, t))
1202			omap2_mcspi_set_fifo(spi, t, 1);
1203
1204		omap2_mcspi_set_enable(spi, 1);
1205
1206		/* RX_ONLY mode needs dummy data in TX reg */
1207		if (t->tx_buf == NULL)
1208			writel_relaxed(0, cs->base
1209					+ OMAP2_MCSPI_TX0);
1210
1211		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1212		    master->cur_msg_mapped &&
1213		    master->can_dma(master, spi, t))
1214			count = omap2_mcspi_txrx_dma(spi, t);
1215		else
1216			count = omap2_mcspi_txrx_pio(spi, t);
1217
1218		if (count != t->len) {
1219			status = -EIO;
1220			goto out;
1221		}
1222	}
1223
1224	omap2_mcspi_set_enable(spi, 0);
1225
1226	if (mcspi->fifo_depth > 0)
1227		omap2_mcspi_set_fifo(spi, t, 0);
1228
1229out:
1230	/* Restore defaults if they were overriden */
1231	if (par_override) {
1232		par_override = 0;
1233		status = omap2_mcspi_setup_transfer(spi, NULL);
1234	}
1235
1236	if (cd && cd->cs_per_word) {
1237		chconf = mcspi->ctx.modulctrl;
1238		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1239		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1240		mcspi->ctx.modulctrl =
1241			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1242	}
1243
1244	omap2_mcspi_set_enable(spi, 0);
1245
1246	if (spi->cs_gpiod)
1247		omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1248
1249	if (mcspi->fifo_depth > 0 && t)
1250		omap2_mcspi_set_fifo(spi, t, 0);
1251
1252	return status;
1253}
1254
1255static int omap2_mcspi_prepare_message(struct spi_master *master,
1256				       struct spi_message *msg)
1257{
1258	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1259	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1260	struct omap2_mcspi_cs	*cs;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1261
1262	/* Only a single channel can have the FORCE bit enabled
 
 
 
 
 
 
 
 
 
 
 
 
1263	 * in its chconf0 register.
1264	 * Scan all channels and disable them except the current one.
1265	 * A FORCE can remain from a last transfer having cs_change enabled
 
 
1266	 */
1267	list_for_each_entry(cs, &ctx->cs, node) {
1268		if (msg->spi->controller_state == cs)
1269			continue;
 
1270
1271		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1272			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1273			writel_relaxed(cs->chconf0,
1274					cs->base + OMAP2_MCSPI_CHCONF0);
1275			readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1276		}
1277	}
1278
1279	return 0;
1280}
1281
1282static bool omap2_mcspi_can_dma(struct spi_master *master,
1283				struct spi_device *spi,
1284				struct spi_transfer *xfer)
1285{
1286	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1287	struct omap2_mcspi_dma *mcspi_dma =
1288		&mcspi->dma_channels[spi->chip_select];
1289
1290	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx)
1291		return false;
1292
1293	if (spi_controller_is_slave(master))
1294		return true;
1295
1296	master->dma_rx = mcspi_dma->dma_rx;
1297	master->dma_tx = mcspi_dma->dma_tx;
1298
1299	return (xfer->len >= DMA_MIN_BYTES);
1300}
1301
1302static size_t omap2_mcspi_max_xfer_size(struct spi_device *spi)
1303{
1304	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
1305	struct omap2_mcspi_dma *mcspi_dma =
1306		&mcspi->dma_channels[spi->chip_select];
1307
1308	if (mcspi->max_xfer_len && mcspi_dma->dma_rx)
1309		return mcspi->max_xfer_len;
1310
1311	return SIZE_MAX;
1312}
1313
1314static int omap2_mcspi_controller_setup(struct omap2_mcspi *mcspi)
1315{
1316	struct spi_master	*master = mcspi->master;
1317	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1318	int			ret = 0;
1319
1320	ret = pm_runtime_get_sync(mcspi->dev);
1321	if (ret < 0) {
1322		pm_runtime_put_noidle(mcspi->dev);
1323
1324		return ret;
1325	}
1326
1327	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1328			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1329	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1330
1331	omap2_mcspi_set_mode(master);
1332	pm_runtime_mark_last_busy(mcspi->dev);
1333	pm_runtime_put_autosuspend(mcspi->dev);
1334	return 0;
1335}
1336
1337static int omap_mcspi_runtime_suspend(struct device *dev)
1338{
1339	int error;
1340
1341	error = pinctrl_pm_select_idle_state(dev);
1342	if (error)
1343		dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1344
1345	return 0;
1346}
1347
1348/*
1349 * When SPI wake up from off-mode, CS is in activate state. If it was in
1350 * inactive state when driver was suspend, then force it to inactive state at
1351 * wake up.
1352 */
1353static int omap_mcspi_runtime_resume(struct device *dev)
1354{
1355	struct spi_master *master = dev_get_drvdata(dev);
1356	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1357	struct omap2_mcspi_regs *ctx = &mcspi->ctx;
1358	struct omap2_mcspi_cs *cs;
1359	int error;
1360
1361	error = pinctrl_pm_select_default_state(dev);
1362	if (error)
1363		dev_warn(dev, "%s: failed to set pins: %i\n", __func__, error);
1364
1365	/* McSPI: context restore */
1366	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
1367	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
1368
1369	list_for_each_entry(cs, &ctx->cs, node) {
1370		/*
1371		 * We need to toggle CS state for OMAP take this
1372		 * change in account.
1373		 */
1374		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1375			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1376			writel_relaxed(cs->chconf0,
1377				       cs->base + OMAP2_MCSPI_CHCONF0);
1378			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1379			writel_relaxed(cs->chconf0,
1380				       cs->base + OMAP2_MCSPI_CHCONF0);
1381		} else {
1382			writel_relaxed(cs->chconf0,
1383				       cs->base + OMAP2_MCSPI_CHCONF0);
1384		}
1385	}
1386
1387	return 0;
1388}
1389
1390static struct omap2_mcspi_platform_config omap2_pdata = {
1391	.regs_offset = 0,
1392};
1393
1394static struct omap2_mcspi_platform_config omap4_pdata = {
1395	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1396};
1397
1398static struct omap2_mcspi_platform_config am654_pdata = {
1399	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1400	.max_xfer_len = SZ_4K - 1,
1401};
1402
1403static const struct of_device_id omap_mcspi_of_match[] = {
1404	{
1405		.compatible = "ti,omap2-mcspi",
1406		.data = &omap2_pdata,
1407	},
1408	{
1409		.compatible = "ti,omap4-mcspi",
1410		.data = &omap4_pdata,
1411	},
1412	{
1413		.compatible = "ti,am654-mcspi",
1414		.data = &am654_pdata,
1415	},
1416	{ },
1417};
1418MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1419
1420static int omap2_mcspi_probe(struct platform_device *pdev)
1421{
1422	struct spi_master	*master;
1423	const struct omap2_mcspi_platform_config *pdata;
1424	struct omap2_mcspi	*mcspi;
1425	struct resource		*r;
1426	int			status = 0, i;
1427	u32			regs_offset = 0;
1428	struct device_node	*node = pdev->dev.of_node;
1429	const struct of_device_id *match;
1430
1431	if (of_property_read_bool(node, "spi-slave"))
1432		master = spi_alloc_slave(&pdev->dev, sizeof(*mcspi));
1433	else
1434		master = spi_alloc_master(&pdev->dev, sizeof(*mcspi));
1435	if (!master)
1436		return -ENOMEM;
1437
1438	/* the spi->mode bits understood by this driver: */
1439	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1440	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1441	master->setup = omap2_mcspi_setup;
1442	master->auto_runtime_pm = true;
1443	master->prepare_message = omap2_mcspi_prepare_message;
1444	master->can_dma = omap2_mcspi_can_dma;
1445	master->transfer_one = omap2_mcspi_transfer_one;
1446	master->set_cs = omap2_mcspi_set_cs;
1447	master->cleanup = omap2_mcspi_cleanup;
1448	master->slave_abort = omap2_mcspi_slave_abort;
1449	master->dev.of_node = node;
1450	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1451	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1452	master->use_gpio_descriptors = true;
1453
1454	platform_set_drvdata(pdev, master);
1455
1456	mcspi = spi_master_get_devdata(master);
1457	mcspi->master = master;
1458
1459	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1460	if (match) {
1461		u32 num_cs = 1; /* default number of chipselect */
1462		pdata = match->data;
1463
1464		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1465		master->num_chipselect = num_cs;
1466		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1467			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1468	} else {
1469		pdata = dev_get_platdata(&pdev->dev);
1470		master->num_chipselect = pdata->num_cs;
1471		mcspi->pin_dir = pdata->pin_dir;
1472	}
1473	regs_offset = pdata->regs_offset;
1474	if (pdata->max_xfer_len) {
1475		mcspi->max_xfer_len = pdata->max_xfer_len;
1476		master->max_transfer_size = omap2_mcspi_max_xfer_size;
1477	}
1478
1479	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1480	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1481	if (IS_ERR(mcspi->base)) {
1482		status = PTR_ERR(mcspi->base);
1483		goto free_master;
1484	}
1485	mcspi->phys = r->start + regs_offset;
1486	mcspi->base += regs_offset;
1487
1488	mcspi->dev = &pdev->dev;
1489
1490	INIT_LIST_HEAD(&mcspi->ctx.cs);
1491
1492	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1493					   sizeof(struct omap2_mcspi_dma),
1494					   GFP_KERNEL);
1495	if (mcspi->dma_channels == NULL) {
1496		status = -ENOMEM;
1497		goto free_master;
1498	}
1499
1500	for (i = 0; i < master->num_chipselect; i++) {
1501		sprintf(mcspi->dma_channels[i].dma_rx_ch_name, "rx%d", i);
1502		sprintf(mcspi->dma_channels[i].dma_tx_ch_name, "tx%d", i);
1503
1504		status = omap2_mcspi_request_dma(mcspi,
1505						 &mcspi->dma_channels[i]);
1506		if (status == -EPROBE_DEFER)
1507			goto free_master;
1508	}
1509
1510	status = platform_get_irq(pdev, 0);
1511	if (status == -EPROBE_DEFER)
1512		goto free_master;
1513	if (status < 0) {
1514		dev_err(&pdev->dev, "no irq resource found\n");
1515		goto free_master;
1516	}
1517	init_completion(&mcspi->txdone);
1518	status = devm_request_irq(&pdev->dev, status,
1519				  omap2_mcspi_irq_handler, 0, pdev->name,
1520				  mcspi);
1521	if (status) {
1522		dev_err(&pdev->dev, "Cannot request IRQ");
1523		goto free_master;
1524	}
1525
 
 
 
 
 
 
 
 
 
 
 
 
 
1526	pm_runtime_use_autosuspend(&pdev->dev);
1527	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1528	pm_runtime_enable(&pdev->dev);
1529
1530	status = omap2_mcspi_controller_setup(mcspi);
1531	if (status < 0)
1532		goto disable_pm;
1533
1534	status = devm_spi_register_controller(&pdev->dev, master);
1535	if (status < 0)
1536		goto disable_pm;
1537
1538	return status;
1539
1540disable_pm:
1541	pm_runtime_dont_use_autosuspend(&pdev->dev);
1542	pm_runtime_put_sync(&pdev->dev);
1543	pm_runtime_disable(&pdev->dev);
1544free_master:
1545	omap2_mcspi_release_dma(master);
1546	spi_master_put(master);
1547	return status;
1548}
1549
1550static int omap2_mcspi_remove(struct platform_device *pdev)
1551{
1552	struct spi_master *master = platform_get_drvdata(pdev);
1553	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1554
1555	omap2_mcspi_release_dma(master);
1556
1557	pm_runtime_dont_use_autosuspend(mcspi->dev);
1558	pm_runtime_put_sync(mcspi->dev);
1559	pm_runtime_disable(&pdev->dev);
1560
1561	return 0;
1562}
1563
1564/* work with hotplug and coldplug */
1565MODULE_ALIAS("platform:omap2_mcspi");
1566
1567static int __maybe_unused omap2_mcspi_suspend(struct device *dev)
1568{
1569	struct spi_master *master = dev_get_drvdata(dev);
1570	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1571	int error;
1572
1573	error = pinctrl_pm_select_sleep_state(dev);
1574	if (error)
1575		dev_warn(mcspi->dev, "%s: failed to set pins: %i\n",
1576			 __func__, error);
1577
1578	error = spi_master_suspend(master);
1579	if (error)
1580		dev_warn(mcspi->dev, "%s: master suspend failed: %i\n",
1581			 __func__, error);
1582
1583	return pm_runtime_force_suspend(dev);
1584}
1585
1586static int __maybe_unused omap2_mcspi_resume(struct device *dev)
1587{
1588	struct spi_master *master = dev_get_drvdata(dev);
1589	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1590	int error;
1591
1592	error = spi_master_resume(master);
1593	if (error)
1594		dev_warn(mcspi->dev, "%s: master resume failed: %i\n",
1595			 __func__, error);
1596
1597	return pm_runtime_force_resume(dev);
1598}
1599
1600static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1601	SET_SYSTEM_SLEEP_PM_OPS(omap2_mcspi_suspend,
1602				omap2_mcspi_resume)
1603	.runtime_suspend	= omap_mcspi_runtime_suspend,
1604	.runtime_resume		= omap_mcspi_runtime_resume,
1605};
1606
1607static struct platform_driver omap2_mcspi_driver = {
1608	.driver = {
1609		.name =		"omap2_mcspi",
1610		.pm =		&omap2_mcspi_pm_ops,
1611		.of_match_table = omap_mcspi_of_match,
1612	},
1613	.probe =	omap2_mcspi_probe,
1614	.remove =	omap2_mcspi_remove,
1615};
1616
1617module_platform_driver(omap2_mcspi_driver);
 
1618MODULE_LICENSE("GPL");