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   1/*
   2 * drivers/spi/spi-fsl-dspi.c
   3 *
   4 * Copyright 2013 Freescale Semiconductor, Inc.
   5 *
   6 * Freescale DSPI driver
   7 * This file contains a driver for the Freescale DSPI
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 */
  15
  16#include <linux/clk.h>
  17#include <linux/delay.h>
  18#include <linux/dmaengine.h>
  19#include <linux/dma-mapping.h>
  20#include <linux/err.h>
  21#include <linux/errno.h>
  22#include <linux/interrupt.h>
  23#include <linux/io.h>
  24#include <linux/kernel.h>
  25#include <linux/math64.h>
  26#include <linux/module.h>
  27#include <linux/of.h>
  28#include <linux/of_device.h>
  29#include <linux/pinctrl/consumer.h>
  30#include <linux/platform_device.h>
  31#include <linux/pm_runtime.h>
  32#include <linux/regmap.h>
  33#include <linux/sched.h>
  34#include <linux/spi/spi.h>
  35#include <linux/spi/spi-fsl-dspi.h>
  36#include <linux/spi/spi_bitbang.h>
  37#include <linux/time.h>
  38
  39#define DRIVER_NAME "fsl-dspi"
  40
  41#define TRAN_STATE_RX_VOID		0x01
  42#define TRAN_STATE_TX_VOID		0x02
  43#define TRAN_STATE_WORD_ODD_NUM	0x04
  44
  45#define DSPI_FIFO_SIZE			4
  46#define DSPI_DMA_BUFSIZE		(DSPI_FIFO_SIZE * 1024)
  47
  48#define SPI_MCR		0x00
  49#define SPI_MCR_MASTER		(1 << 31)
  50#define SPI_MCR_PCSIS		(0x3F << 16)
  51#define SPI_MCR_CLR_TXF	(1 << 11)
  52#define SPI_MCR_CLR_RXF	(1 << 10)
  53
  54#define SPI_TCR			0x08
  55#define SPI_TCR_GET_TCNT(x)	(((x) & 0xffff0000) >> 16)
  56
  57#define SPI_CTAR(x)		(0x0c + (((x) & 0x3) * 4))
  58#define SPI_CTAR_FMSZ(x)	(((x) & 0x0000000f) << 27)
  59#define SPI_CTAR_CPOL(x)	((x) << 26)
  60#define SPI_CTAR_CPHA(x)	((x) << 25)
  61#define SPI_CTAR_LSBFE(x)	((x) << 24)
  62#define SPI_CTAR_PCSSCK(x)	(((x) & 0x00000003) << 22)
  63#define SPI_CTAR_PASC(x)	(((x) & 0x00000003) << 20)
  64#define SPI_CTAR_PDT(x)	(((x) & 0x00000003) << 18)
  65#define SPI_CTAR_PBR(x)	(((x) & 0x00000003) << 16)
  66#define SPI_CTAR_CSSCK(x)	(((x) & 0x0000000f) << 12)
  67#define SPI_CTAR_ASC(x)	(((x) & 0x0000000f) << 8)
  68#define SPI_CTAR_DT(x)		(((x) & 0x0000000f) << 4)
  69#define SPI_CTAR_BR(x)		((x) & 0x0000000f)
  70#define SPI_CTAR_SCALE_BITS	0xf
  71
  72#define SPI_CTAR0_SLAVE	0x0c
  73
  74#define SPI_SR			0x2c
  75#define SPI_SR_EOQF		0x10000000
  76#define SPI_SR_TCFQF		0x80000000
  77#define SPI_SR_CLEAR		0xdaad0000
  78
  79#define SPI_RSER_TFFFE		BIT(25)
  80#define SPI_RSER_TFFFD		BIT(24)
  81#define SPI_RSER_RFDFE		BIT(17)
  82#define SPI_RSER_RFDFD		BIT(16)
  83
  84#define SPI_RSER		0x30
  85#define SPI_RSER_EOQFE		0x10000000
  86#define SPI_RSER_TCFQE		0x80000000
  87
  88#define SPI_PUSHR		0x34
  89#define SPI_PUSHR_CONT		(1 << 31)
  90#define SPI_PUSHR_CTAS(x)	(((x) & 0x00000003) << 28)
  91#define SPI_PUSHR_EOQ		(1 << 27)
  92#define SPI_PUSHR_CTCNT	(1 << 26)
  93#define SPI_PUSHR_PCS(x)	(((1 << x) & 0x0000003f) << 16)
  94#define SPI_PUSHR_TXDATA(x)	((x) & 0x0000ffff)
  95
  96#define SPI_PUSHR_SLAVE	0x34
  97
  98#define SPI_POPR		0x38
  99#define SPI_POPR_RXDATA(x)	((x) & 0x0000ffff)
 100
 101#define SPI_TXFR0		0x3c
 102#define SPI_TXFR1		0x40
 103#define SPI_TXFR2		0x44
 104#define SPI_TXFR3		0x48
 105#define SPI_RXFR0		0x7c
 106#define SPI_RXFR1		0x80
 107#define SPI_RXFR2		0x84
 108#define SPI_RXFR3		0x88
 109
 110#define SPI_FRAME_BITS(bits)	SPI_CTAR_FMSZ((bits) - 1)
 111#define SPI_FRAME_BITS_MASK	SPI_CTAR_FMSZ(0xf)
 112#define SPI_FRAME_BITS_16	SPI_CTAR_FMSZ(0xf)
 113#define SPI_FRAME_BITS_8	SPI_CTAR_FMSZ(0x7)
 114
 115#define SPI_CS_INIT		0x01
 116#define SPI_CS_ASSERT		0x02
 117#define SPI_CS_DROP		0x04
 118
 119#define SPI_TCR_TCNT_MAX	0x10000
 120
 121#define DMA_COMPLETION_TIMEOUT	msecs_to_jiffies(3000)
 122
 123struct chip_data {
 124	u32 mcr_val;
 125	u32 ctar_val;
 126	u16 void_write_data;
 127};
 128
 129enum dspi_trans_mode {
 130	DSPI_EOQ_MODE = 0,
 131	DSPI_TCFQ_MODE,
 132	DSPI_DMA_MODE,
 133};
 134
 135struct fsl_dspi_devtype_data {
 136	enum dspi_trans_mode trans_mode;
 137	u8 max_clock_factor;
 138};
 139
 140static const struct fsl_dspi_devtype_data vf610_data = {
 141	.trans_mode = DSPI_DMA_MODE,
 142	.max_clock_factor = 2,
 143};
 144
 145static const struct fsl_dspi_devtype_data ls1021a_v1_data = {
 146	.trans_mode = DSPI_TCFQ_MODE,
 147	.max_clock_factor = 8,
 148};
 149
 150static const struct fsl_dspi_devtype_data ls2085a_data = {
 151	.trans_mode = DSPI_TCFQ_MODE,
 152	.max_clock_factor = 8,
 153};
 154
 155static const struct fsl_dspi_devtype_data coldfire_data = {
 156	.trans_mode = DSPI_EOQ_MODE,
 157	.max_clock_factor = 8,
 158};
 159
 160struct fsl_dspi_dma {
 161	/* Length of transfer in words of DSPI_FIFO_SIZE */
 162	u32 curr_xfer_len;
 163
 164	u32 *tx_dma_buf;
 165	struct dma_chan *chan_tx;
 166	dma_addr_t tx_dma_phys;
 167	struct completion cmd_tx_complete;
 168	struct dma_async_tx_descriptor *tx_desc;
 169
 170	u32 *rx_dma_buf;
 171	struct dma_chan *chan_rx;
 172	dma_addr_t rx_dma_phys;
 173	struct completion cmd_rx_complete;
 174	struct dma_async_tx_descriptor *rx_desc;
 175};
 176
 177struct fsl_dspi {
 178	struct spi_master	*master;
 179	struct platform_device	*pdev;
 180
 181	struct regmap		*regmap;
 182	int			irq;
 183	struct clk		*clk;
 184
 185	struct spi_transfer	*cur_transfer;
 186	struct spi_message	*cur_msg;
 187	struct chip_data	*cur_chip;
 188	size_t			len;
 189	void			*tx;
 190	void			*tx_end;
 191	void			*rx;
 192	void			*rx_end;
 193	char			dataflags;
 194	u8			cs;
 195	u16			void_write_data;
 196	u32			cs_change;
 197	const struct fsl_dspi_devtype_data *devtype_data;
 198
 199	wait_queue_head_t	waitq;
 200	u32			waitflags;
 201
 202	u32			spi_tcnt;
 203	struct fsl_dspi_dma	*dma;
 204};
 205
 206static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word);
 207
 208static inline int is_double_byte_mode(struct fsl_dspi *dspi)
 209{
 210	unsigned int val;
 211
 212	regmap_read(dspi->regmap, SPI_CTAR(0), &val);
 213
 214	return ((val & SPI_FRAME_BITS_MASK) == SPI_FRAME_BITS(8)) ? 0 : 1;
 215}
 216
 217static void dspi_tx_dma_callback(void *arg)
 218{
 219	struct fsl_dspi *dspi = arg;
 220	struct fsl_dspi_dma *dma = dspi->dma;
 221
 222	complete(&dma->cmd_tx_complete);
 223}
 224
 225static void dspi_rx_dma_callback(void *arg)
 226{
 227	struct fsl_dspi *dspi = arg;
 228	struct fsl_dspi_dma *dma = dspi->dma;
 229	int rx_word;
 230	int i;
 231	u16 d;
 232
 233	rx_word = is_double_byte_mode(dspi);
 234
 235	if (!(dspi->dataflags & TRAN_STATE_RX_VOID)) {
 236		for (i = 0; i < dma->curr_xfer_len; i++) {
 237			d = dspi->dma->rx_dma_buf[i];
 238			rx_word ? (*(u16 *)dspi->rx = d) :
 239						(*(u8 *)dspi->rx = d);
 240			dspi->rx += rx_word + 1;
 241		}
 242	}
 243
 244	complete(&dma->cmd_rx_complete);
 245}
 246
 247static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi)
 248{
 249	struct fsl_dspi_dma *dma = dspi->dma;
 250	struct device *dev = &dspi->pdev->dev;
 251	int time_left;
 252	int tx_word;
 253	int i;
 254
 255	tx_word = is_double_byte_mode(dspi);
 256
 257	for (i = 0; i < dma->curr_xfer_len; i++) {
 258		dspi->dma->tx_dma_buf[i] = dspi_data_to_pushr(dspi, tx_word);
 259		if ((dspi->cs_change) && (!dspi->len))
 260			dspi->dma->tx_dma_buf[i] &= ~SPI_PUSHR_CONT;
 261	}
 262
 263	dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx,
 264					dma->tx_dma_phys,
 265					dma->curr_xfer_len *
 266					DMA_SLAVE_BUSWIDTH_4_BYTES,
 267					DMA_MEM_TO_DEV,
 268					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 269	if (!dma->tx_desc) {
 270		dev_err(dev, "Not able to get desc for DMA xfer\n");
 271		return -EIO;
 272	}
 273
 274	dma->tx_desc->callback = dspi_tx_dma_callback;
 275	dma->tx_desc->callback_param = dspi;
 276	if (dma_submit_error(dmaengine_submit(dma->tx_desc))) {
 277		dev_err(dev, "DMA submit failed\n");
 278		return -EINVAL;
 279	}
 280
 281	dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx,
 282					dma->rx_dma_phys,
 283					dma->curr_xfer_len *
 284					DMA_SLAVE_BUSWIDTH_4_BYTES,
 285					DMA_DEV_TO_MEM,
 286					DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 287	if (!dma->rx_desc) {
 288		dev_err(dev, "Not able to get desc for DMA xfer\n");
 289		return -EIO;
 290	}
 291
 292	dma->rx_desc->callback = dspi_rx_dma_callback;
 293	dma->rx_desc->callback_param = dspi;
 294	if (dma_submit_error(dmaengine_submit(dma->rx_desc))) {
 295		dev_err(dev, "DMA submit failed\n");
 296		return -EINVAL;
 297	}
 298
 299	reinit_completion(&dspi->dma->cmd_rx_complete);
 300	reinit_completion(&dspi->dma->cmd_tx_complete);
 301
 302	dma_async_issue_pending(dma->chan_rx);
 303	dma_async_issue_pending(dma->chan_tx);
 304
 305	time_left = wait_for_completion_timeout(&dspi->dma->cmd_tx_complete,
 306					DMA_COMPLETION_TIMEOUT);
 307	if (time_left == 0) {
 308		dev_err(dev, "DMA tx timeout\n");
 309		dmaengine_terminate_all(dma->chan_tx);
 310		dmaengine_terminate_all(dma->chan_rx);
 311		return -ETIMEDOUT;
 312	}
 313
 314	time_left = wait_for_completion_timeout(&dspi->dma->cmd_rx_complete,
 315					DMA_COMPLETION_TIMEOUT);
 316	if (time_left == 0) {
 317		dev_err(dev, "DMA rx timeout\n");
 318		dmaengine_terminate_all(dma->chan_tx);
 319		dmaengine_terminate_all(dma->chan_rx);
 320		return -ETIMEDOUT;
 321	}
 322
 323	return 0;
 324}
 325
 326static int dspi_dma_xfer(struct fsl_dspi *dspi)
 327{
 328	struct fsl_dspi_dma *dma = dspi->dma;
 329	struct device *dev = &dspi->pdev->dev;
 330	int curr_remaining_bytes;
 331	int bytes_per_buffer;
 332	int word = 1;
 333	int ret = 0;
 334
 335	if (is_double_byte_mode(dspi))
 336		word = 2;
 337	curr_remaining_bytes = dspi->len;
 338	bytes_per_buffer = DSPI_DMA_BUFSIZE / DSPI_FIFO_SIZE;
 339	while (curr_remaining_bytes) {
 340		/* Check if current transfer fits the DMA buffer */
 341		dma->curr_xfer_len = curr_remaining_bytes / word;
 342		if (dma->curr_xfer_len > bytes_per_buffer)
 343			dma->curr_xfer_len = bytes_per_buffer;
 344
 345		ret = dspi_next_xfer_dma_submit(dspi);
 346		if (ret) {
 347			dev_err(dev, "DMA transfer failed\n");
 348			goto exit;
 349
 350		} else {
 351			curr_remaining_bytes -= dma->curr_xfer_len * word;
 352			if (curr_remaining_bytes < 0)
 353				curr_remaining_bytes = 0;
 354		}
 355	}
 356
 357exit:
 358	return ret;
 359}
 360
 361static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr)
 362{
 363	struct fsl_dspi_dma *dma;
 364	struct dma_slave_config cfg;
 365	struct device *dev = &dspi->pdev->dev;
 366	int ret;
 367
 368	dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
 369	if (!dma)
 370		return -ENOMEM;
 371
 372	dma->chan_rx = dma_request_slave_channel(dev, "rx");
 373	if (!dma->chan_rx) {
 374		dev_err(dev, "rx dma channel not available\n");
 375		ret = -ENODEV;
 376		return ret;
 377	}
 378
 379	dma->chan_tx = dma_request_slave_channel(dev, "tx");
 380	if (!dma->chan_tx) {
 381		dev_err(dev, "tx dma channel not available\n");
 382		ret = -ENODEV;
 383		goto err_tx_channel;
 384	}
 385
 386	dma->tx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE,
 387					&dma->tx_dma_phys, GFP_KERNEL);
 388	if (!dma->tx_dma_buf) {
 389		ret = -ENOMEM;
 390		goto err_tx_dma_buf;
 391	}
 392
 393	dma->rx_dma_buf = dma_alloc_coherent(dev, DSPI_DMA_BUFSIZE,
 394					&dma->rx_dma_phys, GFP_KERNEL);
 395	if (!dma->rx_dma_buf) {
 396		ret = -ENOMEM;
 397		goto err_rx_dma_buf;
 398	}
 399
 400	cfg.src_addr = phy_addr + SPI_POPR;
 401	cfg.dst_addr = phy_addr + SPI_PUSHR;
 402	cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 403	cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
 404	cfg.src_maxburst = 1;
 405	cfg.dst_maxburst = 1;
 406
 407	cfg.direction = DMA_DEV_TO_MEM;
 408	ret = dmaengine_slave_config(dma->chan_rx, &cfg);
 409	if (ret) {
 410		dev_err(dev, "can't configure rx dma channel\n");
 411		ret = -EINVAL;
 412		goto err_slave_config;
 413	}
 414
 415	cfg.direction = DMA_MEM_TO_DEV;
 416	ret = dmaengine_slave_config(dma->chan_tx, &cfg);
 417	if (ret) {
 418		dev_err(dev, "can't configure tx dma channel\n");
 419		ret = -EINVAL;
 420		goto err_slave_config;
 421	}
 422
 423	dspi->dma = dma;
 424	init_completion(&dma->cmd_tx_complete);
 425	init_completion(&dma->cmd_rx_complete);
 426
 427	return 0;
 428
 429err_slave_config:
 430	dma_free_coherent(dev, DSPI_DMA_BUFSIZE,
 431			dma->rx_dma_buf, dma->rx_dma_phys);
 432err_rx_dma_buf:
 433	dma_free_coherent(dev, DSPI_DMA_BUFSIZE,
 434			dma->tx_dma_buf, dma->tx_dma_phys);
 435err_tx_dma_buf:
 436	dma_release_channel(dma->chan_tx);
 437err_tx_channel:
 438	dma_release_channel(dma->chan_rx);
 439
 440	devm_kfree(dev, dma);
 441	dspi->dma = NULL;
 442
 443	return ret;
 444}
 445
 446static void dspi_release_dma(struct fsl_dspi *dspi)
 447{
 448	struct fsl_dspi_dma *dma = dspi->dma;
 449	struct device *dev = &dspi->pdev->dev;
 450
 451	if (dma) {
 452		if (dma->chan_tx) {
 453			dma_unmap_single(dev, dma->tx_dma_phys,
 454					DSPI_DMA_BUFSIZE, DMA_TO_DEVICE);
 455			dma_release_channel(dma->chan_tx);
 456		}
 457
 458		if (dma->chan_rx) {
 459			dma_unmap_single(dev, dma->rx_dma_phys,
 460					DSPI_DMA_BUFSIZE, DMA_FROM_DEVICE);
 461			dma_release_channel(dma->chan_rx);
 462		}
 463	}
 464}
 465
 466static void hz_to_spi_baud(char *pbr, char *br, int speed_hz,
 467		unsigned long clkrate)
 468{
 469	/* Valid baud rate pre-scaler values */
 470	int pbr_tbl[4] = {2, 3, 5, 7};
 471	int brs[16] = {	2,	4,	6,	8,
 472		16,	32,	64,	128,
 473		256,	512,	1024,	2048,
 474		4096,	8192,	16384,	32768 };
 475	int scale_needed, scale, minscale = INT_MAX;
 476	int i, j;
 477
 478	scale_needed = clkrate / speed_hz;
 479	if (clkrate % speed_hz)
 480		scale_needed++;
 481
 482	for (i = 0; i < ARRAY_SIZE(brs); i++)
 483		for (j = 0; j < ARRAY_SIZE(pbr_tbl); j++) {
 484			scale = brs[i] * pbr_tbl[j];
 485			if (scale >= scale_needed) {
 486				if (scale < minscale) {
 487					minscale = scale;
 488					*br = i;
 489					*pbr = j;
 490				}
 491				break;
 492			}
 493		}
 494
 495	if (minscale == INT_MAX) {
 496		pr_warn("Can not find valid baud rate,speed_hz is %d,clkrate is %ld, we use the max prescaler value.\n",
 497			speed_hz, clkrate);
 498		*pbr = ARRAY_SIZE(pbr_tbl) - 1;
 499		*br =  ARRAY_SIZE(brs) - 1;
 500	}
 501}
 502
 503static void ns_delay_scale(char *psc, char *sc, int delay_ns,
 504		unsigned long clkrate)
 505{
 506	int pscale_tbl[4] = {1, 3, 5, 7};
 507	int scale_needed, scale, minscale = INT_MAX;
 508	int i, j;
 509	u32 remainder;
 510
 511	scale_needed = div_u64_rem((u64)delay_ns * clkrate, NSEC_PER_SEC,
 512			&remainder);
 513	if (remainder)
 514		scale_needed++;
 515
 516	for (i = 0; i < ARRAY_SIZE(pscale_tbl); i++)
 517		for (j = 0; j <= SPI_CTAR_SCALE_BITS; j++) {
 518			scale = pscale_tbl[i] * (2 << j);
 519			if (scale >= scale_needed) {
 520				if (scale < minscale) {
 521					minscale = scale;
 522					*psc = i;
 523					*sc = j;
 524				}
 525				break;
 526			}
 527		}
 528
 529	if (minscale == INT_MAX) {
 530		pr_warn("Cannot find correct scale values for %dns delay at clkrate %ld, using max prescaler value",
 531			delay_ns, clkrate);
 532		*psc = ARRAY_SIZE(pscale_tbl) - 1;
 533		*sc = SPI_CTAR_SCALE_BITS;
 534	}
 535}
 536
 537static u32 dspi_data_to_pushr(struct fsl_dspi *dspi, int tx_word)
 538{
 539	u16 d16;
 540
 541	if (!(dspi->dataflags & TRAN_STATE_TX_VOID))
 542		d16 = tx_word ? *(u16 *)dspi->tx : *(u8 *)dspi->tx;
 543	else
 544		d16 = dspi->void_write_data;
 545
 546	dspi->tx += tx_word + 1;
 547	dspi->len -= tx_word + 1;
 548
 549	return	SPI_PUSHR_TXDATA(d16) |
 550		SPI_PUSHR_PCS(dspi->cs) |
 551		SPI_PUSHR_CTAS(0) |
 552		SPI_PUSHR_CONT;
 553}
 554
 555static void dspi_data_from_popr(struct fsl_dspi *dspi, int rx_word)
 556{
 557	u16 d;
 558	unsigned int val;
 559
 560	regmap_read(dspi->regmap, SPI_POPR, &val);
 561	d = SPI_POPR_RXDATA(val);
 562
 563	if (!(dspi->dataflags & TRAN_STATE_RX_VOID))
 564		rx_word ? (*(u16 *)dspi->rx = d) : (*(u8 *)dspi->rx = d);
 565
 566	dspi->rx += rx_word + 1;
 567}
 568
 569static int dspi_eoq_write(struct fsl_dspi *dspi)
 570{
 571	int tx_count = 0;
 572	int tx_word;
 573	u32 dspi_pushr = 0;
 574
 575	tx_word = is_double_byte_mode(dspi);
 576
 577	while (dspi->len && (tx_count < DSPI_FIFO_SIZE)) {
 578		/* If we are in word mode, only have a single byte to transfer
 579		 * switch to byte mode temporarily.  Will switch back at the
 580		 * end of the transfer.
 581		 */
 582		if (tx_word && (dspi->len == 1)) {
 583			dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
 584			regmap_update_bits(dspi->regmap, SPI_CTAR(0),
 585					SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
 586			tx_word = 0;
 587		}
 588
 589		dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
 590
 591		if (dspi->len == 0 || tx_count == DSPI_FIFO_SIZE - 1) {
 592			/* last transfer in the transfer */
 593			dspi_pushr |= SPI_PUSHR_EOQ;
 594			if ((dspi->cs_change) && (!dspi->len))
 595				dspi_pushr &= ~SPI_PUSHR_CONT;
 596		} else if (tx_word && (dspi->len == 1))
 597			dspi_pushr |= SPI_PUSHR_EOQ;
 598
 599		regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
 600
 601		tx_count++;
 602	}
 603
 604	return tx_count * (tx_word + 1);
 605}
 606
 607static int dspi_eoq_read(struct fsl_dspi *dspi)
 608{
 609	int rx_count = 0;
 610	int rx_word = is_double_byte_mode(dspi);
 611
 612	while ((dspi->rx < dspi->rx_end)
 613			&& (rx_count < DSPI_FIFO_SIZE)) {
 614		if (rx_word && (dspi->rx_end - dspi->rx) == 1)
 615			rx_word = 0;
 616
 617		dspi_data_from_popr(dspi, rx_word);
 618		rx_count++;
 619	}
 620
 621	return rx_count;
 622}
 623
 624static int dspi_tcfq_write(struct fsl_dspi *dspi)
 625{
 626	int tx_word;
 627	u32 dspi_pushr = 0;
 628
 629	tx_word = is_double_byte_mode(dspi);
 630
 631	if (tx_word && (dspi->len == 1)) {
 632		dspi->dataflags |= TRAN_STATE_WORD_ODD_NUM;
 633		regmap_update_bits(dspi->regmap, SPI_CTAR(0),
 634				SPI_FRAME_BITS_MASK, SPI_FRAME_BITS(8));
 635		tx_word = 0;
 636	}
 637
 638	dspi_pushr = dspi_data_to_pushr(dspi, tx_word);
 639
 640	if ((dspi->cs_change) && (!dspi->len))
 641		dspi_pushr &= ~SPI_PUSHR_CONT;
 642
 643	regmap_write(dspi->regmap, SPI_PUSHR, dspi_pushr);
 644
 645	return tx_word + 1;
 646}
 647
 648static void dspi_tcfq_read(struct fsl_dspi *dspi)
 649{
 650	int rx_word = is_double_byte_mode(dspi);
 651
 652	if (rx_word && (dspi->rx_end - dspi->rx) == 1)
 653		rx_word = 0;
 654
 655	dspi_data_from_popr(dspi, rx_word);
 656}
 657
 658static int dspi_transfer_one_message(struct spi_master *master,
 659		struct spi_message *message)
 660{
 661	struct fsl_dspi *dspi = spi_master_get_devdata(master);
 662	struct spi_device *spi = message->spi;
 663	struct spi_transfer *transfer;
 664	int status = 0;
 665	enum dspi_trans_mode trans_mode;
 666	u32 spi_tcr;
 667
 668	regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
 669	dspi->spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
 670
 671	message->actual_length = 0;
 672
 673	list_for_each_entry(transfer, &message->transfers, transfer_list) {
 674		dspi->cur_transfer = transfer;
 675		dspi->cur_msg = message;
 676		dspi->cur_chip = spi_get_ctldata(spi);
 677		dspi->cs = spi->chip_select;
 678		dspi->cs_change = 0;
 679		if (list_is_last(&dspi->cur_transfer->transfer_list,
 680				 &dspi->cur_msg->transfers) || transfer->cs_change)
 681			dspi->cs_change = 1;
 682		dspi->void_write_data = dspi->cur_chip->void_write_data;
 683
 684		dspi->dataflags = 0;
 685		dspi->tx = (void *)transfer->tx_buf;
 686		dspi->tx_end = dspi->tx + transfer->len;
 687		dspi->rx = transfer->rx_buf;
 688		dspi->rx_end = dspi->rx + transfer->len;
 689		dspi->len = transfer->len;
 690
 691		if (!dspi->rx)
 692			dspi->dataflags |= TRAN_STATE_RX_VOID;
 693
 694		if (!dspi->tx)
 695			dspi->dataflags |= TRAN_STATE_TX_VOID;
 696
 697		regmap_write(dspi->regmap, SPI_MCR, dspi->cur_chip->mcr_val);
 698		regmap_update_bits(dspi->regmap, SPI_MCR,
 699				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF,
 700				SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF);
 701		regmap_write(dspi->regmap, SPI_CTAR(0),
 702				dspi->cur_chip->ctar_val);
 703
 704		trans_mode = dspi->devtype_data->trans_mode;
 705		switch (trans_mode) {
 706		case DSPI_EOQ_MODE:
 707			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_EOQFE);
 708			dspi_eoq_write(dspi);
 709			break;
 710		case DSPI_TCFQ_MODE:
 711			regmap_write(dspi->regmap, SPI_RSER, SPI_RSER_TCFQE);
 712			dspi_tcfq_write(dspi);
 713			break;
 714		case DSPI_DMA_MODE:
 715			regmap_write(dspi->regmap, SPI_RSER,
 716				SPI_RSER_TFFFE | SPI_RSER_TFFFD |
 717				SPI_RSER_RFDFE | SPI_RSER_RFDFD);
 718			status = dspi_dma_xfer(dspi);
 719			break;
 720		default:
 721			dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
 722				trans_mode);
 723			status = -EINVAL;
 724			goto out;
 725		}
 726
 727		if (trans_mode != DSPI_DMA_MODE) {
 728			if (wait_event_interruptible(dspi->waitq,
 729						dspi->waitflags))
 730				dev_err(&dspi->pdev->dev,
 731					"wait transfer complete fail!\n");
 732			dspi->waitflags = 0;
 733		}
 734
 735		if (transfer->delay_usecs)
 736			udelay(transfer->delay_usecs);
 737	}
 738
 739out:
 740	message->status = status;
 741	spi_finalize_current_message(master);
 742
 743	return status;
 744}
 745
 746static int dspi_setup(struct spi_device *spi)
 747{
 748	struct chip_data *chip;
 749	struct fsl_dspi *dspi = spi_master_get_devdata(spi->master);
 750	struct fsl_dspi_platform_data *pdata;
 751	u32 cs_sck_delay = 0, sck_cs_delay = 0;
 752	unsigned char br = 0, pbr = 0, pcssck = 0, cssck = 0;
 753	unsigned char pasc = 0, asc = 0, fmsz = 0;
 754	unsigned long clkrate;
 755
 756	if ((spi->bits_per_word >= 4) && (spi->bits_per_word <= 16)) {
 757		fmsz = spi->bits_per_word - 1;
 758	} else {
 759		pr_err("Invalid wordsize\n");
 760		return -ENODEV;
 761	}
 762
 763	/* Only alloc on first setup */
 764	chip = spi_get_ctldata(spi);
 765	if (chip == NULL) {
 766		chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
 767		if (!chip)
 768			return -ENOMEM;
 769	}
 770
 771	pdata = dev_get_platdata(&dspi->pdev->dev);
 772
 773	if (!pdata) {
 774		of_property_read_u32(spi->dev.of_node, "fsl,spi-cs-sck-delay",
 775				&cs_sck_delay);
 776
 777		of_property_read_u32(spi->dev.of_node, "fsl,spi-sck-cs-delay",
 778				&sck_cs_delay);
 779	} else {
 780		cs_sck_delay = pdata->cs_sck_delay;
 781		sck_cs_delay = pdata->sck_cs_delay;
 782	}
 783
 784	chip->mcr_val = SPI_MCR_MASTER | SPI_MCR_PCSIS |
 785		SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF;
 786
 787	chip->void_write_data = 0;
 788
 789	clkrate = clk_get_rate(dspi->clk);
 790	hz_to_spi_baud(&pbr, &br, spi->max_speed_hz, clkrate);
 791
 792	/* Set PCS to SCK delay scale values */
 793	ns_delay_scale(&pcssck, &cssck, cs_sck_delay, clkrate);
 794
 795	/* Set After SCK delay scale values */
 796	ns_delay_scale(&pasc, &asc, sck_cs_delay, clkrate);
 797
 798	chip->ctar_val =  SPI_CTAR_FMSZ(fmsz)
 799		| SPI_CTAR_CPOL(spi->mode & SPI_CPOL ? 1 : 0)
 800		| SPI_CTAR_CPHA(spi->mode & SPI_CPHA ? 1 : 0)
 801		| SPI_CTAR_LSBFE(spi->mode & SPI_LSB_FIRST ? 1 : 0)
 802		| SPI_CTAR_PCSSCK(pcssck)
 803		| SPI_CTAR_CSSCK(cssck)
 804		| SPI_CTAR_PASC(pasc)
 805		| SPI_CTAR_ASC(asc)
 806		| SPI_CTAR_PBR(pbr)
 807		| SPI_CTAR_BR(br);
 808
 809	spi_set_ctldata(spi, chip);
 810
 811	return 0;
 812}
 813
 814static void dspi_cleanup(struct spi_device *spi)
 815{
 816	struct chip_data *chip = spi_get_ctldata((struct spi_device *)spi);
 817
 818	dev_dbg(&spi->dev, "spi_device %u.%u cleanup\n",
 819			spi->master->bus_num, spi->chip_select);
 820
 821	kfree(chip);
 822}
 823
 824static irqreturn_t dspi_interrupt(int irq, void *dev_id)
 825{
 826	struct fsl_dspi *dspi = (struct fsl_dspi *)dev_id;
 827	struct spi_message *msg = dspi->cur_msg;
 828	enum dspi_trans_mode trans_mode;
 829	u32 spi_sr, spi_tcr;
 830	u32 spi_tcnt, tcnt_diff;
 831	int tx_word;
 832
 833	regmap_read(dspi->regmap, SPI_SR, &spi_sr);
 834	regmap_write(dspi->regmap, SPI_SR, spi_sr);
 835
 836
 837	if (spi_sr & (SPI_SR_EOQF | SPI_SR_TCFQF)) {
 838		tx_word = is_double_byte_mode(dspi);
 839
 840		regmap_read(dspi->regmap, SPI_TCR, &spi_tcr);
 841		spi_tcnt = SPI_TCR_GET_TCNT(spi_tcr);
 842		/*
 843		 * The width of SPI Transfer Counter in SPI_TCR is 16bits,
 844		 * so the max couner is 65535. When the counter reach 65535,
 845		 * it will wrap around, counter reset to zero.
 846		 * spi_tcnt my be less than dspi->spi_tcnt, it means the
 847		 * counter already wrapped around.
 848		 * SPI Transfer Counter is a counter of transmitted frames.
 849		 * The size of frame maybe two bytes.
 850		 */
 851		tcnt_diff = ((spi_tcnt + SPI_TCR_TCNT_MAX) - dspi->spi_tcnt)
 852			% SPI_TCR_TCNT_MAX;
 853		tcnt_diff *= (tx_word + 1);
 854		if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM)
 855			tcnt_diff--;
 856
 857		msg->actual_length += tcnt_diff;
 858
 859		dspi->spi_tcnt = spi_tcnt;
 860
 861		trans_mode = dspi->devtype_data->trans_mode;
 862		switch (trans_mode) {
 863		case DSPI_EOQ_MODE:
 864			dspi_eoq_read(dspi);
 865			break;
 866		case DSPI_TCFQ_MODE:
 867			dspi_tcfq_read(dspi);
 868			break;
 869		default:
 870			dev_err(&dspi->pdev->dev, "unsupported trans_mode %u\n",
 871				trans_mode);
 872				return IRQ_HANDLED;
 873		}
 874
 875		if (!dspi->len) {
 876			if (dspi->dataflags & TRAN_STATE_WORD_ODD_NUM) {
 877				regmap_update_bits(dspi->regmap,
 878						   SPI_CTAR(0),
 879						   SPI_FRAME_BITS_MASK,
 880						   SPI_FRAME_BITS(16));
 881				dspi->dataflags &= ~TRAN_STATE_WORD_ODD_NUM;
 882			}
 883
 884			dspi->waitflags = 1;
 885			wake_up_interruptible(&dspi->waitq);
 886		} else {
 887			switch (trans_mode) {
 888			case DSPI_EOQ_MODE:
 889				dspi_eoq_write(dspi);
 890				break;
 891			case DSPI_TCFQ_MODE:
 892				dspi_tcfq_write(dspi);
 893				break;
 894			default:
 895				dev_err(&dspi->pdev->dev,
 896					"unsupported trans_mode %u\n",
 897					trans_mode);
 898			}
 899		}
 900	}
 901
 902	return IRQ_HANDLED;
 903}
 904
 905static const struct of_device_id fsl_dspi_dt_ids[] = {
 906	{ .compatible = "fsl,vf610-dspi", .data = &vf610_data, },
 907	{ .compatible = "fsl,ls1021a-v1.0-dspi", .data = &ls1021a_v1_data, },
 908	{ .compatible = "fsl,ls2085a-dspi", .data = &ls2085a_data, },
 909	{ /* sentinel */ }
 910};
 911MODULE_DEVICE_TABLE(of, fsl_dspi_dt_ids);
 912
 913#ifdef CONFIG_PM_SLEEP
 914static int dspi_suspend(struct device *dev)
 915{
 916	struct spi_master *master = dev_get_drvdata(dev);
 917	struct fsl_dspi *dspi = spi_master_get_devdata(master);
 918
 919	spi_master_suspend(master);
 920	clk_disable_unprepare(dspi->clk);
 921
 922	pinctrl_pm_select_sleep_state(dev);
 923
 924	return 0;
 925}
 926
 927static int dspi_resume(struct device *dev)
 928{
 929	struct spi_master *master = dev_get_drvdata(dev);
 930	struct fsl_dspi *dspi = spi_master_get_devdata(master);
 931	int ret;
 932
 933	pinctrl_pm_select_default_state(dev);
 934
 935	ret = clk_prepare_enable(dspi->clk);
 936	if (ret)
 937		return ret;
 938	spi_master_resume(master);
 939
 940	return 0;
 941}
 942#endif /* CONFIG_PM_SLEEP */
 943
 944static SIMPLE_DEV_PM_OPS(dspi_pm, dspi_suspend, dspi_resume);
 945
 946static const struct regmap_config dspi_regmap_config = {
 947	.reg_bits = 32,
 948	.val_bits = 32,
 949	.reg_stride = 4,
 950	.max_register = 0x88,
 951};
 952
 953static void dspi_init(struct fsl_dspi *dspi)
 954{
 955	regmap_write(dspi->regmap, SPI_SR, SPI_SR_CLEAR);
 956}
 957
 958static int dspi_probe(struct platform_device *pdev)
 959{
 960	struct device_node *np = pdev->dev.of_node;
 961	struct spi_master *master;
 962	struct fsl_dspi *dspi;
 963	struct resource *res;
 964	void __iomem *base;
 965	struct fsl_dspi_platform_data *pdata;
 966	int ret = 0, cs_num, bus_num;
 967
 968	master = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
 969	if (!master)
 970		return -ENOMEM;
 971
 972	dspi = spi_master_get_devdata(master);
 973	dspi->pdev = pdev;
 974	dspi->master = master;
 975
 976	master->transfer = NULL;
 977	master->setup = dspi_setup;
 978	master->transfer_one_message = dspi_transfer_one_message;
 979	master->dev.of_node = pdev->dev.of_node;
 980
 981	master->cleanup = dspi_cleanup;
 982	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST;
 983	master->bits_per_word_mask = SPI_BPW_MASK(4) | SPI_BPW_MASK(8) |
 984					SPI_BPW_MASK(16);
 985
 986	pdata = dev_get_platdata(&pdev->dev);
 987	if (pdata) {
 988		master->num_chipselect = pdata->cs_num;
 989		master->bus_num = pdata->bus_num;
 990
 991		dspi->devtype_data = &coldfire_data;
 992	} else {
 993
 994		ret = of_property_read_u32(np, "spi-num-chipselects", &cs_num);
 995		if (ret < 0) {
 996			dev_err(&pdev->dev, "can't get spi-num-chipselects\n");
 997			goto out_master_put;
 998		}
 999		master->num_chipselect = cs_num;
1000
1001		ret = of_property_read_u32(np, "bus-num", &bus_num);
1002		if (ret < 0) {
1003			dev_err(&pdev->dev, "can't get bus-num\n");
1004			goto out_master_put;
1005		}
1006		master->bus_num = bus_num;
1007
1008		dspi->devtype_data = of_device_get_match_data(&pdev->dev);
1009		if (!dspi->devtype_data) {
1010			dev_err(&pdev->dev, "can't get devtype_data\n");
1011			ret = -EFAULT;
1012			goto out_master_put;
1013		}
1014	}
1015
1016	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1017	base = devm_ioremap_resource(&pdev->dev, res);
1018	if (IS_ERR(base)) {
1019		ret = PTR_ERR(base);
1020		goto out_master_put;
1021	}
1022
1023	dspi->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
1024						&dspi_regmap_config);
1025	if (IS_ERR(dspi->regmap)) {
1026		dev_err(&pdev->dev, "failed to init regmap: %ld\n",
1027				PTR_ERR(dspi->regmap));
1028		ret = PTR_ERR(dspi->regmap);
1029		goto out_master_put;
1030	}
1031
1032	dspi_init(dspi);
1033	dspi->irq = platform_get_irq(pdev, 0);
1034	if (dspi->irq < 0) {
1035		dev_err(&pdev->dev, "can't get platform irq\n");
1036		ret = dspi->irq;
1037		goto out_master_put;
1038	}
1039
1040	ret = devm_request_irq(&pdev->dev, dspi->irq, dspi_interrupt, 0,
1041			pdev->name, dspi);
1042	if (ret < 0) {
1043		dev_err(&pdev->dev, "Unable to attach DSPI interrupt\n");
1044		goto out_master_put;
1045	}
1046
1047	dspi->clk = devm_clk_get(&pdev->dev, "dspi");
1048	if (IS_ERR(dspi->clk)) {
1049		ret = PTR_ERR(dspi->clk);
1050		dev_err(&pdev->dev, "unable to get clock\n");
1051		goto out_master_put;
1052	}
1053	ret = clk_prepare_enable(dspi->clk);
1054	if (ret)
1055		goto out_master_put;
1056
1057	if (dspi->devtype_data->trans_mode == DSPI_DMA_MODE) {
1058		ret = dspi_request_dma(dspi, res->start);
1059		if (ret < 0) {
1060			dev_err(&pdev->dev, "can't get dma channels\n");
1061			goto out_clk_put;
1062		}
1063	}
1064
1065	master->max_speed_hz =
1066		clk_get_rate(dspi->clk) / dspi->devtype_data->max_clock_factor;
1067
1068	init_waitqueue_head(&dspi->waitq);
1069	platform_set_drvdata(pdev, master);
1070
1071	ret = spi_register_master(master);
1072	if (ret != 0) {
1073		dev_err(&pdev->dev, "Problem registering DSPI master\n");
1074		goto out_clk_put;
1075	}
1076
1077	return ret;
1078
1079out_clk_put:
1080	clk_disable_unprepare(dspi->clk);
1081out_master_put:
1082	spi_master_put(master);
1083
1084	return ret;
1085}
1086
1087static int dspi_remove(struct platform_device *pdev)
1088{
1089	struct spi_master *master = platform_get_drvdata(pdev);
1090	struct fsl_dspi *dspi = spi_master_get_devdata(master);
1091
1092	/* Disconnect from the SPI framework */
1093	dspi_release_dma(dspi);
1094	clk_disable_unprepare(dspi->clk);
1095	spi_unregister_master(dspi->master);
1096
1097	return 0;
1098}
1099
1100static struct platform_driver fsl_dspi_driver = {
1101	.driver.name    = DRIVER_NAME,
1102	.driver.of_match_table = fsl_dspi_dt_ids,
1103	.driver.owner   = THIS_MODULE,
1104	.driver.pm = &dspi_pm,
1105	.probe          = dspi_probe,
1106	.remove		= dspi_remove,
1107};
1108module_platform_driver(fsl_dspi_driver);
1109
1110MODULE_DESCRIPTION("Freescale DSPI Controller Driver");
1111MODULE_LICENSE("GPL");
1112MODULE_ALIAS("platform:" DRIVER_NAME);