1/*
2 * OMAP2 McSPI controller driver
3 *
4 * Copyright (C) 2005, 2006 Nokia Corporation
5 * Author:	Samuel Ortiz <samuel.ortiz@nokia.com> and
6 *		Juha Yrj���l��� <juha.yrjola@nokia.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 */
18
19#include <linux/kernel.h>
20#include <linux/interrupt.h>
21#include <linux/module.h>
22#include <linux/device.h>
23#include <linux/delay.h>
24#include <linux/dma-mapping.h>
25#include <linux/dmaengine.h>
26#include <linux/omap-dma.h>
27#include <linux/platform_device.h>
28#include <linux/err.h>
29#include <linux/clk.h>
30#include <linux/io.h>
31#include <linux/slab.h>
32#include <linux/pm_runtime.h>
33#include <linux/of.h>
34#include <linux/of_device.h>
35#include <linux/gcd.h>
36
37#include <linux/spi/spi.h>
38#include <linux/gpio.h>
39
40#include <linux/platform_data/spi-omap2-mcspi.h>
41
42#define OMAP2_MCSPI_MAX_FREQ		48000000
43#define OMAP2_MCSPI_MAX_DIVIDER		4096
44#define OMAP2_MCSPI_MAX_FIFODEPTH	64
45#define OMAP2_MCSPI_MAX_FIFOWCNT	0xFFFF
46#define SPI_AUTOSUSPEND_TIMEOUT		2000
47
48#define OMAP2_MCSPI_REVISION		0x00
49#define OMAP2_MCSPI_SYSSTATUS		0x14
50#define OMAP2_MCSPI_IRQSTATUS		0x18
51#define OMAP2_MCSPI_IRQENABLE		0x1c
52#define OMAP2_MCSPI_WAKEUPENABLE	0x20
53#define OMAP2_MCSPI_SYST		0x24
54#define OMAP2_MCSPI_MODULCTRL		0x28
55#define OMAP2_MCSPI_XFERLEVEL		0x7c
56
57/* per-channel banks, 0x14 bytes each, first is: */
58#define OMAP2_MCSPI_CHCONF0		0x2c
59#define OMAP2_MCSPI_CHSTAT0		0x30
60#define OMAP2_MCSPI_CHCTRL0		0x34
61#define OMAP2_MCSPI_TX0			0x38
62#define OMAP2_MCSPI_RX0			0x3c
63
64/* per-register bitmasks: */
65#define OMAP2_MCSPI_IRQSTATUS_EOW	BIT(17)
66
67#define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
68#define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
69#define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
70
71#define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
72#define OMAP2_MCSPI_CHCONF_POL		BIT(1)
73#define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
74#define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
75#define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
76#define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
77#define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
78#define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
79#define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
80#define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
81#define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
82#define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
83#define OMAP2_MCSPI_CHCONF_IS		BIT(18)
84#define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
85#define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
86#define OMAP2_MCSPI_CHCONF_FFET		BIT(27)
87#define OMAP2_MCSPI_CHCONF_FFER		BIT(28)
88#define OMAP2_MCSPI_CHCONF_CLKG		BIT(29)
89
90#define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
91#define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
92#define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
93#define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
94
95#define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
96#define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK	(0xff << 8)
97
98#define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
99
100/* We have 2 DMA channels per CS, one for RX and one for TX */
101struct omap2_mcspi_dma {
102	struct dma_chan *dma_tx;
103	struct dma_chan *dma_rx;
104
105	int dma_tx_sync_dev;
106	int dma_rx_sync_dev;
107
108	struct completion dma_tx_completion;
109	struct completion dma_rx_completion;
110
111	char dma_rx_ch_name[14];
112	char dma_tx_ch_name[14];
113};
114
115/* use PIO for small transfers, avoiding DMA setup/teardown overhead and
116 * cache operations; better heuristics consider wordsize and bitrate.
117 */
118#define DMA_MIN_BYTES			160
119
120
121/*
122 * Used for context save and restore, structure members to be updated whenever
123 * corresponding registers are modified.
124 */
125struct omap2_mcspi_regs {
126	u32 modulctrl;
127	u32 wakeupenable;
128	struct list_head cs;
129};
130
131struct omap2_mcspi {
132	struct spi_master	*master;
133	/* Virtual base address of the controller */
134	void __iomem		*base;
135	unsigned long		phys;
136	/* SPI1 has 4 channels, while SPI2 has 2 */
137	struct omap2_mcspi_dma	*dma_channels;
138	struct device		*dev;
139	struct omap2_mcspi_regs ctx;
140	int			fifo_depth;
141	unsigned int		pin_dir:1;
142};
143
144struct omap2_mcspi_cs {
145	void __iomem		*base;
146	unsigned long		phys;
147	int			word_len;
148	u16			mode;
149	struct list_head	node;
150	/* Context save and restore shadow register */
151	u32			chconf0, chctrl0;
152};
153
154static inline void mcspi_write_reg(struct spi_master *master,
155		int idx, u32 val)
156{
157	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
158
159	writel_relaxed(val, mcspi->base + idx);
160}
161
162static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
163{
164	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
165
166	return readl_relaxed(mcspi->base + idx);
167}
168
169static inline void mcspi_write_cs_reg(const struct spi_device *spi,
170		int idx, u32 val)
171{
172	struct omap2_mcspi_cs	*cs = spi->controller_state;
173
174	writel_relaxed(val, cs->base +  idx);
175}
176
177static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
178{
179	struct omap2_mcspi_cs	*cs = spi->controller_state;
180
181	return readl_relaxed(cs->base + idx);
182}
183
184static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
185{
186	struct omap2_mcspi_cs *cs = spi->controller_state;
187
188	return cs->chconf0;
189}
190
191static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
192{
193	struct omap2_mcspi_cs *cs = spi->controller_state;
194
195	cs->chconf0 = val;
196	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
197	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
198}
199
200static inline int mcspi_bytes_per_word(int word_len)
201{
202	if (word_len <= 8)
203		return 1;
204	else if (word_len <= 16)
205		return 2;
206	else /* word_len <= 32 */
207		return 4;
208}
209
210static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
211		int is_read, int enable)
212{
213	u32 l, rw;
214
215	l = mcspi_cached_chconf0(spi);
216
217	if (is_read) /* 1 is read, 0 write */
218		rw = OMAP2_MCSPI_CHCONF_DMAR;
219	else
220		rw = OMAP2_MCSPI_CHCONF_DMAW;
221
222	if (enable)
223		l |= rw;
224	else
225		l &= ~rw;
226
227	mcspi_write_chconf0(spi, l);
228}
229
230static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
231{
232	struct omap2_mcspi_cs *cs = spi->controller_state;
233	u32 l;
234
235	l = cs->chctrl0;
236	if (enable)
237		l |= OMAP2_MCSPI_CHCTRL_EN;
238	else
239		l &= ~OMAP2_MCSPI_CHCTRL_EN;
240	cs->chctrl0 = l;
241	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
242	/* Flash post-writes */
243	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
244}
245
246static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable)
247{
248	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
249	u32 l;
250
251	/* The controller handles the inverted chip selects
252	 * using the OMAP2_MCSPI_CHCONF_EPOL bit so revert
253	 * the inversion from the core spi_set_cs function.
254	 */
255	if (spi->mode & SPI_CS_HIGH)
256		enable = !enable;
257
258	if (spi->controller_state) {
259		int err = pm_runtime_get_sync(mcspi->dev);
260		if (err < 0) {
261			dev_err(mcspi->dev, "failed to get sync: %d\n", err);
262			return;
263		}
264
265		l = mcspi_cached_chconf0(spi);
266
267		if (enable)
268			l &= ~OMAP2_MCSPI_CHCONF_FORCE;
269		else
270			l |= OMAP2_MCSPI_CHCONF_FORCE;
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_master_mode(struct spi_master *master)
280{
281	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
282	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
283	u32 l;
284
285	/*
286	 * Setup when switching from (reset default) slave mode
287	 * to single-channel master mode
288	 */
289	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
290	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
291	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
292	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
293
294	ctx->modulctrl = l;
295}
296
297static void omap2_mcspi_set_fifo(const struct spi_device *spi,
298				struct spi_transfer *t, int enable)
299{
300	struct spi_master *master = spi->master;
301	struct omap2_mcspi_cs *cs = spi->controller_state;
302	struct omap2_mcspi *mcspi;
303	unsigned int wcnt;
304	int max_fifo_depth, fifo_depth, bytes_per_word;
305	u32 chconf, xferlevel;
306
307	mcspi = spi_master_get_devdata(master);
308
309	chconf = mcspi_cached_chconf0(spi);
310	if (enable) {
311		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
312		if (t->len % bytes_per_word != 0)
313			goto disable_fifo;
314
315		if (t->rx_buf != NULL && t->tx_buf != NULL)
316			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
317		else
318			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
319
320		fifo_depth = gcd(t->len, max_fifo_depth);
321		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
322			goto disable_fifo;
323
324		wcnt = t->len / bytes_per_word;
325		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
326			goto disable_fifo;
327
328		xferlevel = wcnt << 16;
329		if (t->rx_buf != NULL) {
330			chconf |= OMAP2_MCSPI_CHCONF_FFER;
331			xferlevel |= (fifo_depth - 1) << 8;
332		}
333		if (t->tx_buf != NULL) {
334			chconf |= OMAP2_MCSPI_CHCONF_FFET;
335			xferlevel |= fifo_depth - 1;
336		}
337
338		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
339		mcspi_write_chconf0(spi, chconf);
340		mcspi->fifo_depth = fifo_depth;
341
342		return;
343	}
344
345disable_fifo:
346	if (t->rx_buf != NULL)
347		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
348
349	if (t->tx_buf != NULL)
350		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
351
352	mcspi_write_chconf0(spi, chconf);
353	mcspi->fifo_depth = 0;
354}
355
356static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
357{
358	struct spi_master	*spi_cntrl = mcspi->master;
359	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
360	struct omap2_mcspi_cs	*cs;
361
362	/* McSPI: context restore */
363	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
364	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
365
366	list_for_each_entry(cs, &ctx->cs, node)
367		writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
368}
369
370static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
371{
372	unsigned long timeout;
373
374	timeout = jiffies + msecs_to_jiffies(1000);
375	while (!(readl_relaxed(reg) & bit)) {
376		if (time_after(jiffies, timeout)) {
377			if (!(readl_relaxed(reg) & bit))
378				return -ETIMEDOUT;
379			else
380				return 0;
381		}
382		cpu_relax();
383	}
384	return 0;
385}
386
387static void omap2_mcspi_rx_callback(void *data)
388{
389	struct spi_device *spi = data;
390	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
391	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
392
393	/* We must disable the DMA RX request */
394	omap2_mcspi_set_dma_req(spi, 1, 0);
395
396	complete(&mcspi_dma->dma_rx_completion);
397}
398
399static void omap2_mcspi_tx_callback(void *data)
400{
401	struct spi_device *spi = data;
402	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
403	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
404
405	/* We must disable the DMA TX request */
406	omap2_mcspi_set_dma_req(spi, 0, 0);
407
408	complete(&mcspi_dma->dma_tx_completion);
409}
410
411static void omap2_mcspi_tx_dma(struct spi_device *spi,
412				struct spi_transfer *xfer,
413				struct dma_slave_config cfg)
414{
415	struct omap2_mcspi	*mcspi;
416	struct omap2_mcspi_dma  *mcspi_dma;
417	unsigned int		count;
418
419	mcspi = spi_master_get_devdata(spi->master);
420	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
421	count = xfer->len;
422
423	if (mcspi_dma->dma_tx) {
424		struct dma_async_tx_descriptor *tx;
425		struct scatterlist sg;
426
427		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
428
429		sg_init_table(&sg, 1);
430		sg_dma_address(&sg) = xfer->tx_dma;
431		sg_dma_len(&sg) = xfer->len;
432
433		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
434		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
435		if (tx) {
436			tx->callback = omap2_mcspi_tx_callback;
437			tx->callback_param = spi;
438			dmaengine_submit(tx);
439		} else {
440			/* FIXME: fall back to PIO? */
441		}
442	}
443	dma_async_issue_pending(mcspi_dma->dma_tx);
444	omap2_mcspi_set_dma_req(spi, 0, 1);
445
446}
447
448static unsigned
449omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
450				struct dma_slave_config cfg,
451				unsigned es)
452{
453	struct omap2_mcspi	*mcspi;
454	struct omap2_mcspi_dma  *mcspi_dma;
455	unsigned int		count, dma_count;
456	u32			l;
457	int			elements = 0;
458	int			word_len, element_count;
459	struct omap2_mcspi_cs	*cs = spi->controller_state;
460	mcspi = spi_master_get_devdata(spi->master);
461	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
462	count = xfer->len;
463	dma_count = xfer->len;
464
465	if (mcspi->fifo_depth == 0)
466		dma_count -= es;
467
468	word_len = cs->word_len;
469	l = mcspi_cached_chconf0(spi);
470
471	if (word_len <= 8)
472		element_count = count;
473	else if (word_len <= 16)
474		element_count = count >> 1;
475	else /* word_len <= 32 */
476		element_count = count >> 2;
477
478	if (mcspi_dma->dma_rx) {
479		struct dma_async_tx_descriptor *tx;
480		struct scatterlist sg;
481
482		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
483
484		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
485			dma_count -= es;
486
487		sg_init_table(&sg, 1);
488		sg_dma_address(&sg) = xfer->rx_dma;
489		sg_dma_len(&sg) = dma_count;
490
491		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
492				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
493				DMA_CTRL_ACK);
494		if (tx) {
495			tx->callback = omap2_mcspi_rx_callback;
496			tx->callback_param = spi;
497			dmaengine_submit(tx);
498		} else {
499				/* FIXME: fall back to PIO? */
500		}
501	}
502
503	dma_async_issue_pending(mcspi_dma->dma_rx);
504	omap2_mcspi_set_dma_req(spi, 1, 1);
505
506	wait_for_completion(&mcspi_dma->dma_rx_completion);
507	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
508			 DMA_FROM_DEVICE);
509
510	if (mcspi->fifo_depth > 0)
511		return count;
512
513	omap2_mcspi_set_enable(spi, 0);
514
515	elements = element_count - 1;
516
517	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
518		elements--;
519
520		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
521				   & OMAP2_MCSPI_CHSTAT_RXS)) {
522			u32 w;
523
524			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
525			if (word_len <= 8)
526				((u8 *)xfer->rx_buf)[elements++] = w;
527			else if (word_len <= 16)
528				((u16 *)xfer->rx_buf)[elements++] = w;
529			else /* word_len <= 32 */
530				((u32 *)xfer->rx_buf)[elements++] = w;
531		} else {
532			int bytes_per_word = mcspi_bytes_per_word(word_len);
533			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
534			count -= (bytes_per_word << 1);
535			omap2_mcspi_set_enable(spi, 1);
536			return count;
537		}
538	}
539	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
540				& OMAP2_MCSPI_CHSTAT_RXS)) {
541		u32 w;
542
543		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
544		if (word_len <= 8)
545			((u8 *)xfer->rx_buf)[elements] = w;
546		else if (word_len <= 16)
547			((u16 *)xfer->rx_buf)[elements] = w;
548		else /* word_len <= 32 */
549			((u32 *)xfer->rx_buf)[elements] = w;
550	} else {
551		dev_err(&spi->dev, "DMA RX last word empty\n");
552		count -= mcspi_bytes_per_word(word_len);
553	}
554	omap2_mcspi_set_enable(spi, 1);
555	return count;
556}
557
558static unsigned
559omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
560{
561	struct omap2_mcspi	*mcspi;
562	struct omap2_mcspi_cs	*cs = spi->controller_state;
563	struct omap2_mcspi_dma  *mcspi_dma;
564	unsigned int		count;
565	u32			l;
566	u8			*rx;
567	const u8		*tx;
568	struct dma_slave_config	cfg;
569	enum dma_slave_buswidth width;
570	unsigned es;
571	u32			burst;
572	void __iomem		*chstat_reg;
573	void __iomem            *irqstat_reg;
574	int			wait_res;
575
576	mcspi = spi_master_get_devdata(spi->master);
577	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
578	l = mcspi_cached_chconf0(spi);
579
580
581	if (cs->word_len <= 8) {
582		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
583		es = 1;
584	} else if (cs->word_len <= 16) {
585		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
586		es = 2;
587	} else {
588		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
589		es = 4;
590	}
591
592	count = xfer->len;
593	burst = 1;
594
595	if (mcspi->fifo_depth > 0) {
596		if (count > mcspi->fifo_depth)
597			burst = mcspi->fifo_depth / es;
598		else
599			burst = count / es;
600	}
601
602	memset(&cfg, 0, sizeof(cfg));
603	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
604	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
605	cfg.src_addr_width = width;
606	cfg.dst_addr_width = width;
607	cfg.src_maxburst = burst;
608	cfg.dst_maxburst = burst;
609
610	rx = xfer->rx_buf;
611	tx = xfer->tx_buf;
612
613	if (tx != NULL)
614		omap2_mcspi_tx_dma(spi, xfer, cfg);
615
616	if (rx != NULL)
617		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
618
619	if (tx != NULL) {
620		wait_for_completion(&mcspi_dma->dma_tx_completion);
621		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
622				 DMA_TO_DEVICE);
623
624		if (mcspi->fifo_depth > 0) {
625			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
626
627			if (mcspi_wait_for_reg_bit(irqstat_reg,
628						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
629				dev_err(&spi->dev, "EOW timed out\n");
630
631			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
632					OMAP2_MCSPI_IRQSTATUS_EOW);
633		}
634
635		/* for TX_ONLY mode, be sure all words have shifted out */
636		if (rx == NULL) {
637			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
638			if (mcspi->fifo_depth > 0) {
639				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
640						OMAP2_MCSPI_CHSTAT_TXFFE);
641				if (wait_res < 0)
642					dev_err(&spi->dev, "TXFFE timed out\n");
643			} else {
644				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
645						OMAP2_MCSPI_CHSTAT_TXS);
646				if (wait_res < 0)
647					dev_err(&spi->dev, "TXS timed out\n");
648			}
649			if (wait_res >= 0 &&
650				(mcspi_wait_for_reg_bit(chstat_reg,
651					OMAP2_MCSPI_CHSTAT_EOT) < 0))
652				dev_err(&spi->dev, "EOT timed out\n");
653		}
654	}
655	return count;
656}
657
658static unsigned
659omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
660{
661	struct omap2_mcspi	*mcspi;
662	struct omap2_mcspi_cs	*cs = spi->controller_state;
663	unsigned int		count, c;
664	u32			l;
665	void __iomem		*base = cs->base;
666	void __iomem		*tx_reg;
667	void __iomem		*rx_reg;
668	void __iomem		*chstat_reg;
669	int			word_len;
670
671	mcspi = spi_master_get_devdata(spi->master);
672	count = xfer->len;
673	c = count;
674	word_len = cs->word_len;
675
676	l = mcspi_cached_chconf0(spi);
677
678	/* We store the pre-calculated register addresses on stack to speed
679	 * up the transfer loop. */
680	tx_reg		= base + OMAP2_MCSPI_TX0;
681	rx_reg		= base + OMAP2_MCSPI_RX0;
682	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
683
684	if (c < (word_len>>3))
685		return 0;
686
687	if (word_len <= 8) {
688		u8		*rx;
689		const u8	*tx;
690
691		rx = xfer->rx_buf;
692		tx = xfer->tx_buf;
693
694		do {
695			c -= 1;
696			if (tx != NULL) {
697				if (mcspi_wait_for_reg_bit(chstat_reg,
698						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
699					dev_err(&spi->dev, "TXS timed out\n");
700					goto out;
701				}
702				dev_vdbg(&spi->dev, "write-%d %02x\n",
703						word_len, *tx);
704				writel_relaxed(*tx++, tx_reg);
705			}
706			if (rx != NULL) {
707				if (mcspi_wait_for_reg_bit(chstat_reg,
708						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
709					dev_err(&spi->dev, "RXS timed out\n");
710					goto out;
711				}
712
713				if (c == 1 && tx == NULL &&
714				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
715					omap2_mcspi_set_enable(spi, 0);
716					*rx++ = readl_relaxed(rx_reg);
717					dev_vdbg(&spi->dev, "read-%d %02x\n",
718						    word_len, *(rx - 1));
719					if (mcspi_wait_for_reg_bit(chstat_reg,
720						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
721						dev_err(&spi->dev,
722							"RXS timed out\n");
723						goto out;
724					}
725					c = 0;
726				} else if (c == 0 && tx == NULL) {
727					omap2_mcspi_set_enable(spi, 0);
728				}
729
730				*rx++ = readl_relaxed(rx_reg);
731				dev_vdbg(&spi->dev, "read-%d %02x\n",
732						word_len, *(rx - 1));
733			}
734		} while (c);
735	} else if (word_len <= 16) {
736		u16		*rx;
737		const u16	*tx;
738
739		rx = xfer->rx_buf;
740		tx = xfer->tx_buf;
741		do {
742			c -= 2;
743			if (tx != NULL) {
744				if (mcspi_wait_for_reg_bit(chstat_reg,
745						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
746					dev_err(&spi->dev, "TXS timed out\n");
747					goto out;
748				}
749				dev_vdbg(&spi->dev, "write-%d %04x\n",
750						word_len, *tx);
751				writel_relaxed(*tx++, tx_reg);
752			}
753			if (rx != NULL) {
754				if (mcspi_wait_for_reg_bit(chstat_reg,
755						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
756					dev_err(&spi->dev, "RXS timed out\n");
757					goto out;
758				}
759
760				if (c == 2 && tx == NULL &&
761				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
762					omap2_mcspi_set_enable(spi, 0);
763					*rx++ = readl_relaxed(rx_reg);
764					dev_vdbg(&spi->dev, "read-%d %04x\n",
765						    word_len, *(rx - 1));
766					if (mcspi_wait_for_reg_bit(chstat_reg,
767						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
768						dev_err(&spi->dev,
769							"RXS timed out\n");
770						goto out;
771					}
772					c = 0;
773				} else if (c == 0 && tx == NULL) {
774					omap2_mcspi_set_enable(spi, 0);
775				}
776
777				*rx++ = readl_relaxed(rx_reg);
778				dev_vdbg(&spi->dev, "read-%d %04x\n",
779						word_len, *(rx - 1));
780			}
781		} while (c >= 2);
782	} else if (word_len <= 32) {
783		u32		*rx;
784		const u32	*tx;
785
786		rx = xfer->rx_buf;
787		tx = xfer->tx_buf;
788		do {
789			c -= 4;
790			if (tx != NULL) {
791				if (mcspi_wait_for_reg_bit(chstat_reg,
792						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
793					dev_err(&spi->dev, "TXS timed out\n");
794					goto out;
795				}
796				dev_vdbg(&spi->dev, "write-%d %08x\n",
797						word_len, *tx);
798				writel_relaxed(*tx++, tx_reg);
799			}
800			if (rx != NULL) {
801				if (mcspi_wait_for_reg_bit(chstat_reg,
802						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
803					dev_err(&spi->dev, "RXS timed out\n");
804					goto out;
805				}
806
807				if (c == 4 && tx == NULL &&
808				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
809					omap2_mcspi_set_enable(spi, 0);
810					*rx++ = readl_relaxed(rx_reg);
811					dev_vdbg(&spi->dev, "read-%d %08x\n",
812						    word_len, *(rx - 1));
813					if (mcspi_wait_for_reg_bit(chstat_reg,
814						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
815						dev_err(&spi->dev,
816							"RXS timed out\n");
817						goto out;
818					}
819					c = 0;
820				} else if (c == 0 && tx == NULL) {
821					omap2_mcspi_set_enable(spi, 0);
822				}
823
824				*rx++ = readl_relaxed(rx_reg);
825				dev_vdbg(&spi->dev, "read-%d %08x\n",
826						word_len, *(rx - 1));
827			}
828		} while (c >= 4);
829	}
830
831	/* for TX_ONLY mode, be sure all words have shifted out */
832	if (xfer->rx_buf == NULL) {
833		if (mcspi_wait_for_reg_bit(chstat_reg,
834				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
835			dev_err(&spi->dev, "TXS timed out\n");
836		} else if (mcspi_wait_for_reg_bit(chstat_reg,
837				OMAP2_MCSPI_CHSTAT_EOT) < 0)
838			dev_err(&spi->dev, "EOT timed out\n");
839
840		/* disable chan to purge rx datas received in TX_ONLY transfer,
841		 * otherwise these rx datas will affect the direct following
842		 * RX_ONLY transfer.
843		 */
844		omap2_mcspi_set_enable(spi, 0);
845	}
846out:
847	omap2_mcspi_set_enable(spi, 1);
848	return count - c;
849}
850
851static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
852{
853	u32 div;
854
855	for (div = 0; div < 15; div++)
856		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
857			return div;
858
859	return 15;
860}
861
862/* called only when no transfer is active to this device */
863static int omap2_mcspi_setup_transfer(struct spi_device *spi,
864		struct spi_transfer *t)
865{
866	struct omap2_mcspi_cs *cs = spi->controller_state;
867	struct omap2_mcspi *mcspi;
868	struct spi_master *spi_cntrl;
869	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
870	u8 word_len = spi->bits_per_word;
871	u32 speed_hz = spi->max_speed_hz;
872
873	mcspi = spi_master_get_devdata(spi->master);
874	spi_cntrl = mcspi->master;
875
876	if (t != NULL && t->bits_per_word)
877		word_len = t->bits_per_word;
878
879	cs->word_len = word_len;
880
881	if (t && t->speed_hz)
882		speed_hz = t->speed_hz;
883
884	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
885	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
886		clkd = omap2_mcspi_calc_divisor(speed_hz);
887		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
888		clkg = 0;
889	} else {
890		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
891		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
892		clkd = (div - 1) & 0xf;
893		extclk = (div - 1) >> 4;
894		clkg = OMAP2_MCSPI_CHCONF_CLKG;
895	}
896
897	l = mcspi_cached_chconf0(spi);
898
899	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
900	 * REVISIT: this controller could support SPI_3WIRE mode.
901	 */
902	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
903		l &= ~OMAP2_MCSPI_CHCONF_IS;
904		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
905		l |= OMAP2_MCSPI_CHCONF_DPE0;
906	} else {
907		l |= OMAP2_MCSPI_CHCONF_IS;
908		l |= OMAP2_MCSPI_CHCONF_DPE1;
909		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
910	}
911
912	/* wordlength */
913	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
914	l |= (word_len - 1) << 7;
915
916	/* set chipselect polarity; manage with FORCE */
917	if (!(spi->mode & SPI_CS_HIGH))
918		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
919	else
920		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
921
922	/* set clock divisor */
923	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
924	l |= clkd << 2;
925
926	/* set clock granularity */
927	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
928	l |= clkg;
929	if (clkg) {
930		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
931		cs->chctrl0 |= extclk << 8;
932		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
933	}
934
935	/* set SPI mode 0..3 */
936	if (spi->mode & SPI_CPOL)
937		l |= OMAP2_MCSPI_CHCONF_POL;
938	else
939		l &= ~OMAP2_MCSPI_CHCONF_POL;
940	if (spi->mode & SPI_CPHA)
941		l |= OMAP2_MCSPI_CHCONF_PHA;
942	else
943		l &= ~OMAP2_MCSPI_CHCONF_PHA;
944
945	mcspi_write_chconf0(spi, l);
946
947	cs->mode = spi->mode;
948
949	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
950			speed_hz,
951			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
952			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
953
954	return 0;
955}
956
957/*
958 * Note that we currently allow DMA only if we get a channel
959 * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
960 */
961static int omap2_mcspi_request_dma(struct spi_device *spi)
962{
963	struct spi_master	*master = spi->master;
964	struct omap2_mcspi	*mcspi;
965	struct omap2_mcspi_dma	*mcspi_dma;
966	dma_cap_mask_t mask;
967	unsigned sig;
968
969	mcspi = spi_master_get_devdata(master);
970	mcspi_dma = mcspi->dma_channels + spi->chip_select;
971
972	init_completion(&mcspi_dma->dma_rx_completion);
973	init_completion(&mcspi_dma->dma_tx_completion);
974
975	dma_cap_zero(mask);
976	dma_cap_set(DMA_SLAVE, mask);
977	sig = mcspi_dma->dma_rx_sync_dev;
978
979	mcspi_dma->dma_rx =
980		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
981						 &sig, &master->dev,
982						 mcspi_dma->dma_rx_ch_name);
983	if (!mcspi_dma->dma_rx)
984		goto no_dma;
985
986	sig = mcspi_dma->dma_tx_sync_dev;
987	mcspi_dma->dma_tx =
988		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
989						 &sig, &master->dev,
990						 mcspi_dma->dma_tx_ch_name);
991
992	if (!mcspi_dma->dma_tx) {
993		dma_release_channel(mcspi_dma->dma_rx);
994		mcspi_dma->dma_rx = NULL;
995		goto no_dma;
996	}
997
998	return 0;
999
1000no_dma:
1001	dev_warn(&spi->dev, "not using DMA for McSPI\n");
1002	return -EAGAIN;
1003}
1004
1005static int omap2_mcspi_setup(struct spi_device *spi)
1006{
1007	int			ret;
1008	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
1009	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1010	struct omap2_mcspi_dma	*mcspi_dma;
1011	struct omap2_mcspi_cs	*cs = spi->controller_state;
1012
1013	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1014
1015	if (!cs) {
1016		cs = kzalloc(sizeof *cs, GFP_KERNEL);
1017		if (!cs)
1018			return -ENOMEM;
1019		cs->base = mcspi->base + spi->chip_select * 0x14;
1020		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1021		cs->mode = 0;
1022		cs->chconf0 = 0;
1023		cs->chctrl0 = 0;
1024		spi->controller_state = cs;
1025		/* Link this to context save list */
1026		list_add_tail(&cs->node, &ctx->cs);
1027
1028		if (gpio_is_valid(spi->cs_gpio)) {
1029			ret = gpio_request(spi->cs_gpio, dev_name(&spi->dev));
1030			if (ret) {
1031				dev_err(&spi->dev, "failed to request gpio\n");
1032				return ret;
1033			}
1034			gpio_direction_output(spi->cs_gpio,
1035					 !(spi->mode & SPI_CS_HIGH));
1036		}
1037	}
1038
1039	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1040		ret = omap2_mcspi_request_dma(spi);
1041		if (ret < 0 && ret != -EAGAIN)
1042			return ret;
1043	}
1044
1045	ret = pm_runtime_get_sync(mcspi->dev);
1046	if (ret < 0)
1047		return ret;
1048
1049	ret = omap2_mcspi_setup_transfer(spi, NULL);
1050	pm_runtime_mark_last_busy(mcspi->dev);
1051	pm_runtime_put_autosuspend(mcspi->dev);
1052
1053	return ret;
1054}
1055
1056static void omap2_mcspi_cleanup(struct spi_device *spi)
1057{
1058	struct omap2_mcspi	*mcspi;
1059	struct omap2_mcspi_dma	*mcspi_dma;
1060	struct omap2_mcspi_cs	*cs;
1061
1062	mcspi = spi_master_get_devdata(spi->master);
1063
1064	if (spi->controller_state) {
1065		/* Unlink controller state from context save list */
1066		cs = spi->controller_state;
1067		list_del(&cs->node);
1068
1069		kfree(cs);
1070	}
1071
1072	if (spi->chip_select < spi->master->num_chipselect) {
1073		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1074
1075		if (mcspi_dma->dma_rx) {
1076			dma_release_channel(mcspi_dma->dma_rx);
1077			mcspi_dma->dma_rx = NULL;
1078		}
1079		if (mcspi_dma->dma_tx) {
1080			dma_release_channel(mcspi_dma->dma_tx);
1081			mcspi_dma->dma_tx = NULL;
1082		}
1083	}
1084
1085	if (gpio_is_valid(spi->cs_gpio))
1086		gpio_free(spi->cs_gpio);
1087}
1088
1089static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
1090		struct spi_device *spi, struct spi_transfer *t)
1091{
1092
1093	/* We only enable one channel at a time -- the one whose message is
1094	 * -- although this controller would gladly
1095	 * arbitrate among multiple channels.  This corresponds to "single
1096	 * channel" master mode.  As a side effect, we need to manage the
1097	 * chipselect with the FORCE bit ... CS != channel enable.
1098	 */
1099
1100	struct spi_master		*master;
1101	struct omap2_mcspi_dma		*mcspi_dma;
1102	struct omap2_mcspi_cs		*cs;
1103	struct omap2_mcspi_device_config *cd;
1104	int				par_override = 0;
1105	int				status = 0;
1106	u32				chconf;
1107
1108	master = spi->master;
1109	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1110	cs = spi->controller_state;
1111	cd = spi->controller_data;
1112
1113	/*
1114	 * The slave driver could have changed spi->mode in which case
1115	 * it will be different from cs->mode (the current hardware setup).
1116	 * If so, set par_override (even though its not a parity issue) so
1117	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1118	 * with the correct mode on the first iteration of the loop below.
1119	 */
1120	if (spi->mode != cs->mode)
1121		par_override = 1;
1122
1123	omap2_mcspi_set_enable(spi, 0);
1124
1125	if (gpio_is_valid(spi->cs_gpio))
1126		omap2_mcspi_set_cs(spi, spi->mode & SPI_CS_HIGH);
1127
1128	if (par_override ||
1129	    (t->speed_hz != spi->max_speed_hz) ||
1130	    (t->bits_per_word != spi->bits_per_word)) {
1131		par_override = 1;
1132		status = omap2_mcspi_setup_transfer(spi, t);
1133		if (status < 0)
1134			goto out;
1135		if (t->speed_hz == spi->max_speed_hz &&
1136		    t->bits_per_word == spi->bits_per_word)
1137			par_override = 0;
1138	}
1139	if (cd && cd->cs_per_word) {
1140		chconf = mcspi->ctx.modulctrl;
1141		chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1142		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1143		mcspi->ctx.modulctrl =
1144			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1145	}
1146
1147	chconf = mcspi_cached_chconf0(spi);
1148	chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1149	chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1150
1151	if (t->tx_buf == NULL)
1152		chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1153	else if (t->rx_buf == NULL)
1154		chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1155
1156	if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1157		/* Turbo mode is for more than one word */
1158		if (t->len > ((cs->word_len + 7) >> 3))
1159			chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1160	}
1161
1162	mcspi_write_chconf0(spi, chconf);
1163
1164	if (t->len) {
1165		unsigned	count;
1166
1167		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1168		    (t->len >= DMA_MIN_BYTES))
1169			omap2_mcspi_set_fifo(spi, t, 1);
1170
1171		omap2_mcspi_set_enable(spi, 1);
1172
1173		/* RX_ONLY mode needs dummy data in TX reg */
1174		if (t->tx_buf == NULL)
1175			writel_relaxed(0, cs->base
1176					+ OMAP2_MCSPI_TX0);
1177
1178		if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1179		    (t->len >= DMA_MIN_BYTES))
1180			count = omap2_mcspi_txrx_dma(spi, t);
1181		else
1182			count = omap2_mcspi_txrx_pio(spi, t);
1183
1184		if (count != t->len) {
1185			status = -EIO;
1186			goto out;
1187		}
1188	}
1189
1190	omap2_mcspi_set_enable(spi, 0);
1191
1192	if (mcspi->fifo_depth > 0)
1193		omap2_mcspi_set_fifo(spi, t, 0);
1194
1195out:
1196	/* Restore defaults if they were overriden */
1197	if (par_override) {
1198		par_override = 0;
1199		status = omap2_mcspi_setup_transfer(spi, NULL);
1200	}
1201
1202	if (cd && cd->cs_per_word) {
1203		chconf = mcspi->ctx.modulctrl;
1204		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1205		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1206		mcspi->ctx.modulctrl =
1207			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1208	}
1209
1210	omap2_mcspi_set_enable(spi, 0);
1211
1212	if (gpio_is_valid(spi->cs_gpio))
1213		omap2_mcspi_set_cs(spi, !(spi->mode & SPI_CS_HIGH));
1214
1215	if (mcspi->fifo_depth > 0 && t)
1216		omap2_mcspi_set_fifo(spi, t, 0);
1217
1218	return status;
1219}
1220
1221static int omap2_mcspi_prepare_message(struct spi_master *master,
1222				       struct spi_message *msg)
1223{
1224	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1225	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1226	struct omap2_mcspi_cs	*cs;
1227
1228	/* Only a single channel can have the FORCE bit enabled
1229	 * in its chconf0 register.
1230	 * Scan all channels and disable them except the current one.
1231	 * A FORCE can remain from a last transfer having cs_change enabled
1232	 */
1233	list_for_each_entry(cs, &ctx->cs, node) {
1234		if (msg->spi->controller_state == cs)
1235			continue;
1236
1237		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE)) {
1238			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1239			writel_relaxed(cs->chconf0,
1240					cs->base + OMAP2_MCSPI_CHCONF0);
1241			readl_relaxed(cs->base + OMAP2_MCSPI_CHCONF0);
1242		}
1243	}
1244
1245	return 0;
1246}
1247
1248static int omap2_mcspi_transfer_one(struct spi_master *master,
1249		struct spi_device *spi, struct spi_transfer *t)
1250{
1251	struct omap2_mcspi	*mcspi;
1252	struct omap2_mcspi_dma	*mcspi_dma;
1253	const void	*tx_buf = t->tx_buf;
1254	void		*rx_buf = t->rx_buf;
1255	unsigned	len = t->len;
1256
1257	mcspi = spi_master_get_devdata(master);
1258	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1259
1260	if ((len && !(rx_buf || tx_buf))) {
1261		dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1262				t->speed_hz,
1263				len,
1264				tx_buf ? "tx" : "",
1265				rx_buf ? "rx" : "",
1266				t->bits_per_word);
1267		return -EINVAL;
1268	}
1269
1270	if (len < DMA_MIN_BYTES)
1271		goto skip_dma_map;
1272
1273	if (mcspi_dma->dma_tx && tx_buf != NULL) {
1274		t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1275				len, DMA_TO_DEVICE);
1276		if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1277			dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1278					'T', len);
1279			return -EINVAL;
1280		}
1281	}
1282	if (mcspi_dma->dma_rx && rx_buf != NULL) {
1283		t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1284				DMA_FROM_DEVICE);
1285		if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1286			dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1287					'R', len);
1288			if (tx_buf != NULL)
1289				dma_unmap_single(mcspi->dev, t->tx_dma,
1290						len, DMA_TO_DEVICE);
1291			return -EINVAL;
1292		}
1293	}
1294
1295skip_dma_map:
1296	return omap2_mcspi_work_one(mcspi, spi, t);
1297}
1298
1299static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1300{
1301	struct spi_master	*master = mcspi->master;
1302	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1303	int			ret = 0;
1304
1305	ret = pm_runtime_get_sync(mcspi->dev);
1306	if (ret < 0)
1307		return ret;
1308
1309	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1310			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1311	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1312
1313	omap2_mcspi_set_master_mode(master);
1314	pm_runtime_mark_last_busy(mcspi->dev);
1315	pm_runtime_put_autosuspend(mcspi->dev);
1316	return 0;
1317}
1318
1319static int omap_mcspi_runtime_resume(struct device *dev)
1320{
1321	struct omap2_mcspi	*mcspi;
1322	struct spi_master	*master;
1323
1324	master = dev_get_drvdata(dev);
1325	mcspi = spi_master_get_devdata(master);
1326	omap2_mcspi_restore_ctx(mcspi);
1327
1328	return 0;
1329}
1330
1331static struct omap2_mcspi_platform_config omap2_pdata = {
1332	.regs_offset = 0,
1333};
1334
1335static struct omap2_mcspi_platform_config omap4_pdata = {
1336	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1337};
1338
1339static const struct of_device_id omap_mcspi_of_match[] = {
1340	{
1341		.compatible = "ti,omap2-mcspi",
1342		.data = &omap2_pdata,
1343	},
1344	{
1345		.compatible = "ti,omap4-mcspi",
1346		.data = &omap4_pdata,
1347	},
1348	{ },
1349};
1350MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1351
1352static int omap2_mcspi_probe(struct platform_device *pdev)
1353{
1354	struct spi_master	*master;
1355	const struct omap2_mcspi_platform_config *pdata;
1356	struct omap2_mcspi	*mcspi;
1357	struct resource		*r;
1358	int			status = 0, i;
1359	u32			regs_offset = 0;
1360	static int		bus_num = 1;
1361	struct device_node	*node = pdev->dev.of_node;
1362	const struct of_device_id *match;
1363
1364	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1365	if (master == NULL) {
1366		dev_dbg(&pdev->dev, "master allocation failed\n");
1367		return -ENOMEM;
1368	}
1369
1370	/* the spi->mode bits understood by this driver: */
1371	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1372	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1373	master->setup = omap2_mcspi_setup;
1374	master->auto_runtime_pm = true;
1375	master->prepare_message = omap2_mcspi_prepare_message;
1376	master->transfer_one = omap2_mcspi_transfer_one;
1377	master->set_cs = omap2_mcspi_set_cs;
1378	master->cleanup = omap2_mcspi_cleanup;
1379	master->dev.of_node = node;
1380	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1381	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1382
1383	platform_set_drvdata(pdev, master);
1384
1385	mcspi = spi_master_get_devdata(master);
1386	mcspi->master = master;
1387
1388	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1389	if (match) {
1390		u32 num_cs = 1; /* default number of chipselect */
1391		pdata = match->data;
1392
1393		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1394		master->num_chipselect = num_cs;
1395		master->bus_num = bus_num++;
1396		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1397			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1398	} else {
1399		pdata = dev_get_platdata(&pdev->dev);
1400		master->num_chipselect = pdata->num_cs;
1401		if (pdev->id != -1)
1402			master->bus_num = pdev->id;
1403		mcspi->pin_dir = pdata->pin_dir;
1404	}
1405	regs_offset = pdata->regs_offset;
1406
1407	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1408	if (r == NULL) {
1409		status = -ENODEV;
1410		goto free_master;
1411	}
1412
1413	r->start += regs_offset;
1414	r->end += regs_offset;
1415	mcspi->phys = r->start;
1416
1417	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1418	if (IS_ERR(mcspi->base)) {
1419		status = PTR_ERR(mcspi->base);
1420		goto free_master;
1421	}
1422
1423	mcspi->dev = &pdev->dev;
1424
1425	INIT_LIST_HEAD(&mcspi->ctx.cs);
1426
1427	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1428					   sizeof(struct omap2_mcspi_dma),
1429					   GFP_KERNEL);
1430	if (mcspi->dma_channels == NULL) {
1431		status = -ENOMEM;
1432		goto free_master;
1433	}
1434
1435	for (i = 0; i < master->num_chipselect; i++) {
1436		char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1437		char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1438		struct resource *dma_res;
1439
1440		sprintf(dma_rx_ch_name, "rx%d", i);
1441		if (!pdev->dev.of_node) {
1442			dma_res =
1443				platform_get_resource_byname(pdev,
1444							     IORESOURCE_DMA,
1445							     dma_rx_ch_name);
1446			if (!dma_res) {
1447				dev_dbg(&pdev->dev,
1448					"cannot get DMA RX channel\n");
1449				status = -ENODEV;
1450				break;
1451			}
1452
1453			mcspi->dma_channels[i].dma_rx_sync_dev =
1454				dma_res->start;
1455		}
1456		sprintf(dma_tx_ch_name, "tx%d", i);
1457		if (!pdev->dev.of_node) {
1458			dma_res =
1459				platform_get_resource_byname(pdev,
1460							     IORESOURCE_DMA,
1461							     dma_tx_ch_name);
1462			if (!dma_res) {
1463				dev_dbg(&pdev->dev,
1464					"cannot get DMA TX channel\n");
1465				status = -ENODEV;
1466				break;
1467			}
1468
1469			mcspi->dma_channels[i].dma_tx_sync_dev =
1470				dma_res->start;
1471		}
1472	}
1473
1474	if (status < 0)
1475		goto free_master;
1476
1477	pm_runtime_use_autosuspend(&pdev->dev);
1478	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1479	pm_runtime_enable(&pdev->dev);
1480
1481	status = omap2_mcspi_master_setup(mcspi);
1482	if (status < 0)
1483		goto disable_pm;
1484
1485	status = devm_spi_register_master(&pdev->dev, master);
1486	if (status < 0)
1487		goto disable_pm;
1488
1489	return status;
1490
1491disable_pm:
1492	pm_runtime_disable(&pdev->dev);
1493free_master:
1494	spi_master_put(master);
1495	return status;
1496}
1497
1498static int omap2_mcspi_remove(struct platform_device *pdev)
1499{
1500	struct spi_master *master = platform_get_drvdata(pdev);
1501	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1502
1503	pm_runtime_put_sync(mcspi->dev);
1504	pm_runtime_disable(&pdev->dev);
1505
1506	return 0;
1507}
1508
1509/* work with hotplug and coldplug */
1510MODULE_ALIAS("platform:omap2_mcspi");
1511
1512#ifdef	CONFIG_SUSPEND
1513/*
1514 * When SPI wake up from off-mode, CS is in activate state. If it was in
1515 * unactive state when driver was suspend, then force it to unactive state at
1516 * wake up.
1517 */
1518static int omap2_mcspi_resume(struct device *dev)
1519{
1520	struct spi_master	*master = dev_get_drvdata(dev);
1521	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1522	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1523	struct omap2_mcspi_cs	*cs;
1524
1525	pm_runtime_get_sync(mcspi->dev);
1526	list_for_each_entry(cs, &ctx->cs, node) {
1527		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1528			/*
1529			 * We need to toggle CS state for OMAP take this
1530			 * change in account.
1531			 */
1532			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1533			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1534			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1535			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1536		}
1537	}
1538	pm_runtime_mark_last_busy(mcspi->dev);
1539	pm_runtime_put_autosuspend(mcspi->dev);
1540	return 0;
1541}
1542#else
1543#define	omap2_mcspi_resume	NULL
1544#endif
1545
1546static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1547	.resume = omap2_mcspi_resume,
1548	.runtime_resume	= omap_mcspi_runtime_resume,
1549};
1550
1551static struct platform_driver omap2_mcspi_driver = {
1552	.driver = {
1553		.name =		"omap2_mcspi",
1554		.pm =		&omap2_mcspi_pm_ops,
1555		.of_match_table = omap_mcspi_of_match,
1556	},
1557	.probe =	omap2_mcspi_probe,
1558	.remove =	omap2_mcspi_remove,
1559};
1560
1561module_platform_driver(omap2_mcspi_driver);
1562MODULE_LICENSE("GPL");
1563