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