xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision 3c6a73cc)
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  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21  *
22  */
23 
24 #include <linux/kernel.h>
25 #include <linux/interrupt.h>
26 #include <linux/module.h>
27 #include <linux/device.h>
28 #include <linux/delay.h>
29 #include <linux/dma-mapping.h>
30 #include <linux/dmaengine.h>
31 #include <linux/omap-dma.h>
32 #include <linux/platform_device.h>
33 #include <linux/err.h>
34 #include <linux/clk.h>
35 #include <linux/io.h>
36 #include <linux/slab.h>
37 #include <linux/pm_runtime.h>
38 #include <linux/of.h>
39 #include <linux/of_device.h>
40 #include <linux/gcd.h>
41 
42 #include <linux/spi/spi.h>
43 
44 #include <linux/platform_data/spi-omap2-mcspi.h>
45 
46 #define OMAP2_MCSPI_MAX_FREQ		48000000
47 #define OMAP2_MCSPI_MAX_DIVIDER		4096
48 #define OMAP2_MCSPI_MAX_FIFODEPTH	64
49 #define OMAP2_MCSPI_MAX_FIFOWCNT	0xFFFF
50 #define SPI_AUTOSUSPEND_TIMEOUT		2000
51 
52 #define OMAP2_MCSPI_REVISION		0x00
53 #define OMAP2_MCSPI_SYSSTATUS		0x14
54 #define OMAP2_MCSPI_IRQSTATUS		0x18
55 #define OMAP2_MCSPI_IRQENABLE		0x1c
56 #define OMAP2_MCSPI_WAKEUPENABLE	0x20
57 #define OMAP2_MCSPI_SYST		0x24
58 #define OMAP2_MCSPI_MODULCTRL		0x28
59 #define OMAP2_MCSPI_XFERLEVEL		0x7c
60 
61 /* per-channel banks, 0x14 bytes each, first is: */
62 #define OMAP2_MCSPI_CHCONF0		0x2c
63 #define OMAP2_MCSPI_CHSTAT0		0x30
64 #define OMAP2_MCSPI_CHCTRL0		0x34
65 #define OMAP2_MCSPI_TX0			0x38
66 #define OMAP2_MCSPI_RX0			0x3c
67 
68 /* per-register bitmasks: */
69 #define OMAP2_MCSPI_IRQSTATUS_EOW	BIT(17)
70 
71 #define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
72 #define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
73 #define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
74 
75 #define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
76 #define OMAP2_MCSPI_CHCONF_POL		BIT(1)
77 #define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
78 #define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
79 #define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
80 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
81 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
82 #define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
83 #define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
84 #define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
85 #define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
86 #define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
87 #define OMAP2_MCSPI_CHCONF_IS		BIT(18)
88 #define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
89 #define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
90 #define OMAP2_MCSPI_CHCONF_FFET		BIT(27)
91 #define OMAP2_MCSPI_CHCONF_FFER		BIT(28)
92 #define OMAP2_MCSPI_CHCONF_CLKG		BIT(29)
93 
94 #define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
95 #define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
96 #define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
97 #define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
98 
99 #define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
100 #define OMAP2_MCSPI_CHCTRL_EXTCLK_MASK	(0xff << 8)
101 
102 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
103 
104 /* We have 2 DMA channels per CS, one for RX and one for TX */
105 struct omap2_mcspi_dma {
106 	struct dma_chan *dma_tx;
107 	struct dma_chan *dma_rx;
108 
109 	int dma_tx_sync_dev;
110 	int dma_rx_sync_dev;
111 
112 	struct completion dma_tx_completion;
113 	struct completion dma_rx_completion;
114 
115 	char dma_rx_ch_name[14];
116 	char dma_tx_ch_name[14];
117 };
118 
119 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
120  * cache operations; better heuristics consider wordsize and bitrate.
121  */
122 #define DMA_MIN_BYTES			160
123 
124 
125 /*
126  * Used for context save and restore, structure members to be updated whenever
127  * corresponding registers are modified.
128  */
129 struct omap2_mcspi_regs {
130 	u32 modulctrl;
131 	u32 wakeupenable;
132 	struct list_head cs;
133 };
134 
135 struct omap2_mcspi {
136 	struct spi_master	*master;
137 	/* Virtual base address of the controller */
138 	void __iomem		*base;
139 	unsigned long		phys;
140 	/* SPI1 has 4 channels, while SPI2 has 2 */
141 	struct omap2_mcspi_dma	*dma_channels;
142 	struct device		*dev;
143 	struct omap2_mcspi_regs ctx;
144 	int			fifo_depth;
145 	unsigned int		pin_dir:1;
146 };
147 
148 struct omap2_mcspi_cs {
149 	void __iomem		*base;
150 	unsigned long		phys;
151 	int			word_len;
152 	u16			mode;
153 	struct list_head	node;
154 	/* Context save and restore shadow register */
155 	u32			chconf0, chctrl0;
156 };
157 
158 static inline void mcspi_write_reg(struct spi_master *master,
159 		int idx, u32 val)
160 {
161 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
162 
163 	writel_relaxed(val, mcspi->base + idx);
164 }
165 
166 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
167 {
168 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
169 
170 	return readl_relaxed(mcspi->base + idx);
171 }
172 
173 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
174 		int idx, u32 val)
175 {
176 	struct omap2_mcspi_cs	*cs = spi->controller_state;
177 
178 	writel_relaxed(val, cs->base +  idx);
179 }
180 
181 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
182 {
183 	struct omap2_mcspi_cs	*cs = spi->controller_state;
184 
185 	return readl_relaxed(cs->base + idx);
186 }
187 
188 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
189 {
190 	struct omap2_mcspi_cs *cs = spi->controller_state;
191 
192 	return cs->chconf0;
193 }
194 
195 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
196 {
197 	struct omap2_mcspi_cs *cs = spi->controller_state;
198 
199 	cs->chconf0 = val;
200 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
201 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
202 }
203 
204 static inline int mcspi_bytes_per_word(int word_len)
205 {
206 	if (word_len <= 8)
207 		return 1;
208 	else if (word_len <= 16)
209 		return 2;
210 	else /* word_len <= 32 */
211 		return 4;
212 }
213 
214 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
215 		int is_read, int enable)
216 {
217 	u32 l, rw;
218 
219 	l = mcspi_cached_chconf0(spi);
220 
221 	if (is_read) /* 1 is read, 0 write */
222 		rw = OMAP2_MCSPI_CHCONF_DMAR;
223 	else
224 		rw = OMAP2_MCSPI_CHCONF_DMAW;
225 
226 	if (enable)
227 		l |= rw;
228 	else
229 		l &= ~rw;
230 
231 	mcspi_write_chconf0(spi, l);
232 }
233 
234 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
235 {
236 	struct omap2_mcspi_cs *cs = spi->controller_state;
237 	u32 l;
238 
239 	l = cs->chctrl0;
240 	if (enable)
241 		l |= OMAP2_MCSPI_CHCTRL_EN;
242 	else
243 		l &= ~OMAP2_MCSPI_CHCTRL_EN;
244 	cs->chctrl0 = l;
245 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
246 	/* Flash post-writes */
247 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
248 }
249 
250 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
251 {
252 	u32 l;
253 
254 	l = mcspi_cached_chconf0(spi);
255 	if (cs_active)
256 		l |= OMAP2_MCSPI_CHCONF_FORCE;
257 	else
258 		l &= ~OMAP2_MCSPI_CHCONF_FORCE;
259 
260 	mcspi_write_chconf0(spi, l);
261 }
262 
263 static void omap2_mcspi_set_master_mode(struct spi_master *master)
264 {
265 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
266 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
267 	u32 l;
268 
269 	/*
270 	 * Setup when switching from (reset default) slave mode
271 	 * to single-channel master mode
272 	 */
273 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
274 	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
275 	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
276 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
277 
278 	ctx->modulctrl = l;
279 }
280 
281 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
282 				struct spi_transfer *t, int enable)
283 {
284 	struct spi_master *master = spi->master;
285 	struct omap2_mcspi_cs *cs = spi->controller_state;
286 	struct omap2_mcspi *mcspi;
287 	unsigned int wcnt;
288 	int max_fifo_depth, fifo_depth, bytes_per_word;
289 	u32 chconf, xferlevel;
290 
291 	mcspi = spi_master_get_devdata(master);
292 
293 	chconf = mcspi_cached_chconf0(spi);
294 	if (enable) {
295 		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
296 		if (t->len % bytes_per_word != 0)
297 			goto disable_fifo;
298 
299 		if (t->rx_buf != NULL && t->tx_buf != NULL)
300 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
301 		else
302 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
303 
304 		fifo_depth = gcd(t->len, max_fifo_depth);
305 		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
306 			goto disable_fifo;
307 
308 		wcnt = t->len / bytes_per_word;
309 		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
310 			goto disable_fifo;
311 
312 		xferlevel = wcnt << 16;
313 		if (t->rx_buf != NULL) {
314 			chconf |= OMAP2_MCSPI_CHCONF_FFER;
315 			xferlevel |= (fifo_depth - 1) << 8;
316 		}
317 		if (t->tx_buf != NULL) {
318 			chconf |= OMAP2_MCSPI_CHCONF_FFET;
319 			xferlevel |= fifo_depth - 1;
320 		}
321 
322 		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
323 		mcspi_write_chconf0(spi, chconf);
324 		mcspi->fifo_depth = fifo_depth;
325 
326 		return;
327 	}
328 
329 disable_fifo:
330 	if (t->rx_buf != NULL)
331 		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
332 
333 	if (t->tx_buf != NULL)
334 		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
335 
336 	mcspi_write_chconf0(spi, chconf);
337 	mcspi->fifo_depth = 0;
338 }
339 
340 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
341 {
342 	struct spi_master	*spi_cntrl = mcspi->master;
343 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
344 	struct omap2_mcspi_cs	*cs;
345 
346 	/* McSPI: context restore */
347 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
348 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
349 
350 	list_for_each_entry(cs, &ctx->cs, node)
351 		writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
352 }
353 
354 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
355 {
356 	unsigned long timeout;
357 
358 	timeout = jiffies + msecs_to_jiffies(1000);
359 	while (!(readl_relaxed(reg) & bit)) {
360 		if (time_after(jiffies, timeout)) {
361 			if (!(readl_relaxed(reg) & bit))
362 				return -ETIMEDOUT;
363 			else
364 				return 0;
365 		}
366 		cpu_relax();
367 	}
368 	return 0;
369 }
370 
371 static void omap2_mcspi_rx_callback(void *data)
372 {
373 	struct spi_device *spi = data;
374 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
375 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
376 
377 	/* We must disable the DMA RX request */
378 	omap2_mcspi_set_dma_req(spi, 1, 0);
379 
380 	complete(&mcspi_dma->dma_rx_completion);
381 }
382 
383 static void omap2_mcspi_tx_callback(void *data)
384 {
385 	struct spi_device *spi = data;
386 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
387 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
388 
389 	/* We must disable the DMA TX request */
390 	omap2_mcspi_set_dma_req(spi, 0, 0);
391 
392 	complete(&mcspi_dma->dma_tx_completion);
393 }
394 
395 static void omap2_mcspi_tx_dma(struct spi_device *spi,
396 				struct spi_transfer *xfer,
397 				struct dma_slave_config cfg)
398 {
399 	struct omap2_mcspi	*mcspi;
400 	struct omap2_mcspi_dma  *mcspi_dma;
401 	unsigned int		count;
402 
403 	mcspi = spi_master_get_devdata(spi->master);
404 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
405 	count = xfer->len;
406 
407 	if (mcspi_dma->dma_tx) {
408 		struct dma_async_tx_descriptor *tx;
409 		struct scatterlist sg;
410 
411 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
412 
413 		sg_init_table(&sg, 1);
414 		sg_dma_address(&sg) = xfer->tx_dma;
415 		sg_dma_len(&sg) = xfer->len;
416 
417 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
418 		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
419 		if (tx) {
420 			tx->callback = omap2_mcspi_tx_callback;
421 			tx->callback_param = spi;
422 			dmaengine_submit(tx);
423 		} else {
424 			/* FIXME: fall back to PIO? */
425 		}
426 	}
427 	dma_async_issue_pending(mcspi_dma->dma_tx);
428 	omap2_mcspi_set_dma_req(spi, 0, 1);
429 
430 }
431 
432 static unsigned
433 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
434 				struct dma_slave_config cfg,
435 				unsigned es)
436 {
437 	struct omap2_mcspi	*mcspi;
438 	struct omap2_mcspi_dma  *mcspi_dma;
439 	unsigned int		count, dma_count;
440 	u32			l;
441 	int			elements = 0;
442 	int			word_len, element_count;
443 	struct omap2_mcspi_cs	*cs = spi->controller_state;
444 	mcspi = spi_master_get_devdata(spi->master);
445 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
446 	count = xfer->len;
447 	dma_count = xfer->len;
448 
449 	if (mcspi->fifo_depth == 0)
450 		dma_count -= es;
451 
452 	word_len = cs->word_len;
453 	l = mcspi_cached_chconf0(spi);
454 
455 	if (word_len <= 8)
456 		element_count = count;
457 	else if (word_len <= 16)
458 		element_count = count >> 1;
459 	else /* word_len <= 32 */
460 		element_count = count >> 2;
461 
462 	if (mcspi_dma->dma_rx) {
463 		struct dma_async_tx_descriptor *tx;
464 		struct scatterlist sg;
465 
466 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
467 
468 		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
469 			dma_count -= es;
470 
471 		sg_init_table(&sg, 1);
472 		sg_dma_address(&sg) = xfer->rx_dma;
473 		sg_dma_len(&sg) = dma_count;
474 
475 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
476 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
477 				DMA_CTRL_ACK);
478 		if (tx) {
479 			tx->callback = omap2_mcspi_rx_callback;
480 			tx->callback_param = spi;
481 			dmaengine_submit(tx);
482 		} else {
483 				/* FIXME: fall back to PIO? */
484 		}
485 	}
486 
487 	dma_async_issue_pending(mcspi_dma->dma_rx);
488 	omap2_mcspi_set_dma_req(spi, 1, 1);
489 
490 	wait_for_completion(&mcspi_dma->dma_rx_completion);
491 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
492 			 DMA_FROM_DEVICE);
493 
494 	if (mcspi->fifo_depth > 0)
495 		return count;
496 
497 	omap2_mcspi_set_enable(spi, 0);
498 
499 	elements = element_count - 1;
500 
501 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
502 		elements--;
503 
504 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
505 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
506 			u32 w;
507 
508 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
509 			if (word_len <= 8)
510 				((u8 *)xfer->rx_buf)[elements++] = w;
511 			else if (word_len <= 16)
512 				((u16 *)xfer->rx_buf)[elements++] = w;
513 			else /* word_len <= 32 */
514 				((u32 *)xfer->rx_buf)[elements++] = w;
515 		} else {
516 			int bytes_per_word = mcspi_bytes_per_word(word_len);
517 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
518 			count -= (bytes_per_word << 1);
519 			omap2_mcspi_set_enable(spi, 1);
520 			return count;
521 		}
522 	}
523 	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
524 				& OMAP2_MCSPI_CHSTAT_RXS)) {
525 		u32 w;
526 
527 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
528 		if (word_len <= 8)
529 			((u8 *)xfer->rx_buf)[elements] = w;
530 		else if (word_len <= 16)
531 			((u16 *)xfer->rx_buf)[elements] = w;
532 		else /* word_len <= 32 */
533 			((u32 *)xfer->rx_buf)[elements] = w;
534 	} else {
535 		dev_err(&spi->dev, "DMA RX last word empty\n");
536 		count -= mcspi_bytes_per_word(word_len);
537 	}
538 	omap2_mcspi_set_enable(spi, 1);
539 	return count;
540 }
541 
542 static unsigned
543 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
544 {
545 	struct omap2_mcspi	*mcspi;
546 	struct omap2_mcspi_cs	*cs = spi->controller_state;
547 	struct omap2_mcspi_dma  *mcspi_dma;
548 	unsigned int		count;
549 	u32			l;
550 	u8			*rx;
551 	const u8		*tx;
552 	struct dma_slave_config	cfg;
553 	enum dma_slave_buswidth width;
554 	unsigned es;
555 	u32			burst;
556 	void __iomem		*chstat_reg;
557 	void __iomem            *irqstat_reg;
558 	int			wait_res;
559 
560 	mcspi = spi_master_get_devdata(spi->master);
561 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
562 	l = mcspi_cached_chconf0(spi);
563 
564 
565 	if (cs->word_len <= 8) {
566 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
567 		es = 1;
568 	} else if (cs->word_len <= 16) {
569 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
570 		es = 2;
571 	} else {
572 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
573 		es = 4;
574 	}
575 
576 	count = xfer->len;
577 	burst = 1;
578 
579 	if (mcspi->fifo_depth > 0) {
580 		if (count > mcspi->fifo_depth)
581 			burst = mcspi->fifo_depth / es;
582 		else
583 			burst = count / es;
584 	}
585 
586 	memset(&cfg, 0, sizeof(cfg));
587 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
588 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
589 	cfg.src_addr_width = width;
590 	cfg.dst_addr_width = width;
591 	cfg.src_maxburst = burst;
592 	cfg.dst_maxburst = burst;
593 
594 	rx = xfer->rx_buf;
595 	tx = xfer->tx_buf;
596 
597 	if (tx != NULL)
598 		omap2_mcspi_tx_dma(spi, xfer, cfg);
599 
600 	if (rx != NULL)
601 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
602 
603 	if (tx != NULL) {
604 		wait_for_completion(&mcspi_dma->dma_tx_completion);
605 		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
606 				 DMA_TO_DEVICE);
607 
608 		if (mcspi->fifo_depth > 0) {
609 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
610 
611 			if (mcspi_wait_for_reg_bit(irqstat_reg,
612 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
613 				dev_err(&spi->dev, "EOW timed out\n");
614 
615 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
616 					OMAP2_MCSPI_IRQSTATUS_EOW);
617 		}
618 
619 		/* for TX_ONLY mode, be sure all words have shifted out */
620 		if (rx == NULL) {
621 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
622 			if (mcspi->fifo_depth > 0) {
623 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
624 						OMAP2_MCSPI_CHSTAT_TXFFE);
625 				if (wait_res < 0)
626 					dev_err(&spi->dev, "TXFFE timed out\n");
627 			} else {
628 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
629 						OMAP2_MCSPI_CHSTAT_TXS);
630 				if (wait_res < 0)
631 					dev_err(&spi->dev, "TXS timed out\n");
632 			}
633 			if (wait_res >= 0 &&
634 				(mcspi_wait_for_reg_bit(chstat_reg,
635 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
636 				dev_err(&spi->dev, "EOT timed out\n");
637 		}
638 	}
639 	return count;
640 }
641 
642 static unsigned
643 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
644 {
645 	struct omap2_mcspi	*mcspi;
646 	struct omap2_mcspi_cs	*cs = spi->controller_state;
647 	unsigned int		count, c;
648 	u32			l;
649 	void __iomem		*base = cs->base;
650 	void __iomem		*tx_reg;
651 	void __iomem		*rx_reg;
652 	void __iomem		*chstat_reg;
653 	int			word_len;
654 
655 	mcspi = spi_master_get_devdata(spi->master);
656 	count = xfer->len;
657 	c = count;
658 	word_len = cs->word_len;
659 
660 	l = mcspi_cached_chconf0(spi);
661 
662 	/* We store the pre-calculated register addresses on stack to speed
663 	 * up the transfer loop. */
664 	tx_reg		= base + OMAP2_MCSPI_TX0;
665 	rx_reg		= base + OMAP2_MCSPI_RX0;
666 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
667 
668 	if (c < (word_len>>3))
669 		return 0;
670 
671 	if (word_len <= 8) {
672 		u8		*rx;
673 		const u8	*tx;
674 
675 		rx = xfer->rx_buf;
676 		tx = xfer->tx_buf;
677 
678 		do {
679 			c -= 1;
680 			if (tx != NULL) {
681 				if (mcspi_wait_for_reg_bit(chstat_reg,
682 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
683 					dev_err(&spi->dev, "TXS timed out\n");
684 					goto out;
685 				}
686 				dev_vdbg(&spi->dev, "write-%d %02x\n",
687 						word_len, *tx);
688 				writel_relaxed(*tx++, tx_reg);
689 			}
690 			if (rx != NULL) {
691 				if (mcspi_wait_for_reg_bit(chstat_reg,
692 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
693 					dev_err(&spi->dev, "RXS timed out\n");
694 					goto out;
695 				}
696 
697 				if (c == 1 && tx == NULL &&
698 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
699 					omap2_mcspi_set_enable(spi, 0);
700 					*rx++ = readl_relaxed(rx_reg);
701 					dev_vdbg(&spi->dev, "read-%d %02x\n",
702 						    word_len, *(rx - 1));
703 					if (mcspi_wait_for_reg_bit(chstat_reg,
704 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
705 						dev_err(&spi->dev,
706 							"RXS timed out\n");
707 						goto out;
708 					}
709 					c = 0;
710 				} else if (c == 0 && tx == NULL) {
711 					omap2_mcspi_set_enable(spi, 0);
712 				}
713 
714 				*rx++ = readl_relaxed(rx_reg);
715 				dev_vdbg(&spi->dev, "read-%d %02x\n",
716 						word_len, *(rx - 1));
717 			}
718 		} while (c);
719 	} else if (word_len <= 16) {
720 		u16		*rx;
721 		const u16	*tx;
722 
723 		rx = xfer->rx_buf;
724 		tx = xfer->tx_buf;
725 		do {
726 			c -= 2;
727 			if (tx != NULL) {
728 				if (mcspi_wait_for_reg_bit(chstat_reg,
729 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
730 					dev_err(&spi->dev, "TXS timed out\n");
731 					goto out;
732 				}
733 				dev_vdbg(&spi->dev, "write-%d %04x\n",
734 						word_len, *tx);
735 				writel_relaxed(*tx++, tx_reg);
736 			}
737 			if (rx != NULL) {
738 				if (mcspi_wait_for_reg_bit(chstat_reg,
739 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
740 					dev_err(&spi->dev, "RXS timed out\n");
741 					goto out;
742 				}
743 
744 				if (c == 2 && tx == NULL &&
745 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
746 					omap2_mcspi_set_enable(spi, 0);
747 					*rx++ = readl_relaxed(rx_reg);
748 					dev_vdbg(&spi->dev, "read-%d %04x\n",
749 						    word_len, *(rx - 1));
750 					if (mcspi_wait_for_reg_bit(chstat_reg,
751 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
752 						dev_err(&spi->dev,
753 							"RXS timed out\n");
754 						goto out;
755 					}
756 					c = 0;
757 				} else if (c == 0 && tx == NULL) {
758 					omap2_mcspi_set_enable(spi, 0);
759 				}
760 
761 				*rx++ = readl_relaxed(rx_reg);
762 				dev_vdbg(&spi->dev, "read-%d %04x\n",
763 						word_len, *(rx - 1));
764 			}
765 		} while (c >= 2);
766 	} else if (word_len <= 32) {
767 		u32		*rx;
768 		const u32	*tx;
769 
770 		rx = xfer->rx_buf;
771 		tx = xfer->tx_buf;
772 		do {
773 			c -= 4;
774 			if (tx != NULL) {
775 				if (mcspi_wait_for_reg_bit(chstat_reg,
776 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
777 					dev_err(&spi->dev, "TXS timed out\n");
778 					goto out;
779 				}
780 				dev_vdbg(&spi->dev, "write-%d %08x\n",
781 						word_len, *tx);
782 				writel_relaxed(*tx++, tx_reg);
783 			}
784 			if (rx != NULL) {
785 				if (mcspi_wait_for_reg_bit(chstat_reg,
786 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
787 					dev_err(&spi->dev, "RXS timed out\n");
788 					goto out;
789 				}
790 
791 				if (c == 4 && tx == NULL &&
792 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
793 					omap2_mcspi_set_enable(spi, 0);
794 					*rx++ = readl_relaxed(rx_reg);
795 					dev_vdbg(&spi->dev, "read-%d %08x\n",
796 						    word_len, *(rx - 1));
797 					if (mcspi_wait_for_reg_bit(chstat_reg,
798 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
799 						dev_err(&spi->dev,
800 							"RXS timed out\n");
801 						goto out;
802 					}
803 					c = 0;
804 				} else if (c == 0 && tx == NULL) {
805 					omap2_mcspi_set_enable(spi, 0);
806 				}
807 
808 				*rx++ = readl_relaxed(rx_reg);
809 				dev_vdbg(&spi->dev, "read-%d %08x\n",
810 						word_len, *(rx - 1));
811 			}
812 		} while (c >= 4);
813 	}
814 
815 	/* for TX_ONLY mode, be sure all words have shifted out */
816 	if (xfer->rx_buf == NULL) {
817 		if (mcspi_wait_for_reg_bit(chstat_reg,
818 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
819 			dev_err(&spi->dev, "TXS timed out\n");
820 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
821 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
822 			dev_err(&spi->dev, "EOT timed out\n");
823 
824 		/* disable chan to purge rx datas received in TX_ONLY transfer,
825 		 * otherwise these rx datas will affect the direct following
826 		 * RX_ONLY transfer.
827 		 */
828 		omap2_mcspi_set_enable(spi, 0);
829 	}
830 out:
831 	omap2_mcspi_set_enable(spi, 1);
832 	return count - c;
833 }
834 
835 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
836 {
837 	u32 div;
838 
839 	for (div = 0; div < 15; div++)
840 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
841 			return div;
842 
843 	return 15;
844 }
845 
846 /* called only when no transfer is active to this device */
847 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
848 		struct spi_transfer *t)
849 {
850 	struct omap2_mcspi_cs *cs = spi->controller_state;
851 	struct omap2_mcspi *mcspi;
852 	struct spi_master *spi_cntrl;
853 	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
854 	u8 word_len = spi->bits_per_word;
855 	u32 speed_hz = spi->max_speed_hz;
856 
857 	mcspi = spi_master_get_devdata(spi->master);
858 	spi_cntrl = mcspi->master;
859 
860 	if (t != NULL && t->bits_per_word)
861 		word_len = t->bits_per_word;
862 
863 	cs->word_len = word_len;
864 
865 	if (t && t->speed_hz)
866 		speed_hz = t->speed_hz;
867 
868 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
869 	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
870 		clkd = omap2_mcspi_calc_divisor(speed_hz);
871 		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
872 		clkg = 0;
873 	} else {
874 		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
875 		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
876 		clkd = (div - 1) & 0xf;
877 		extclk = (div - 1) >> 4;
878 		clkg = OMAP2_MCSPI_CHCONF_CLKG;
879 	}
880 
881 	l = mcspi_cached_chconf0(spi);
882 
883 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
884 	 * REVISIT: this controller could support SPI_3WIRE mode.
885 	 */
886 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
887 		l &= ~OMAP2_MCSPI_CHCONF_IS;
888 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
889 		l |= OMAP2_MCSPI_CHCONF_DPE0;
890 	} else {
891 		l |= OMAP2_MCSPI_CHCONF_IS;
892 		l |= OMAP2_MCSPI_CHCONF_DPE1;
893 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
894 	}
895 
896 	/* wordlength */
897 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
898 	l |= (word_len - 1) << 7;
899 
900 	/* set chipselect polarity; manage with FORCE */
901 	if (!(spi->mode & SPI_CS_HIGH))
902 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
903 	else
904 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
905 
906 	/* set clock divisor */
907 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
908 	l |= clkd << 2;
909 
910 	/* set clock granularity */
911 	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
912 	l |= clkg;
913 	if (clkg) {
914 		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
915 		cs->chctrl0 |= extclk << 8;
916 		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
917 	}
918 
919 	/* set SPI mode 0..3 */
920 	if (spi->mode & SPI_CPOL)
921 		l |= OMAP2_MCSPI_CHCONF_POL;
922 	else
923 		l &= ~OMAP2_MCSPI_CHCONF_POL;
924 	if (spi->mode & SPI_CPHA)
925 		l |= OMAP2_MCSPI_CHCONF_PHA;
926 	else
927 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
928 
929 	mcspi_write_chconf0(spi, l);
930 
931 	cs->mode = spi->mode;
932 
933 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
934 			speed_hz,
935 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
936 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
937 
938 	return 0;
939 }
940 
941 /*
942  * Note that we currently allow DMA only if we get a channel
943  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
944  */
945 static int omap2_mcspi_request_dma(struct spi_device *spi)
946 {
947 	struct spi_master	*master = spi->master;
948 	struct omap2_mcspi	*mcspi;
949 	struct omap2_mcspi_dma	*mcspi_dma;
950 	dma_cap_mask_t mask;
951 	unsigned sig;
952 
953 	mcspi = spi_master_get_devdata(master);
954 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
955 
956 	init_completion(&mcspi_dma->dma_rx_completion);
957 	init_completion(&mcspi_dma->dma_tx_completion);
958 
959 	dma_cap_zero(mask);
960 	dma_cap_set(DMA_SLAVE, mask);
961 	sig = mcspi_dma->dma_rx_sync_dev;
962 
963 	mcspi_dma->dma_rx =
964 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
965 						 &sig, &master->dev,
966 						 mcspi_dma->dma_rx_ch_name);
967 	if (!mcspi_dma->dma_rx)
968 		goto no_dma;
969 
970 	sig = mcspi_dma->dma_tx_sync_dev;
971 	mcspi_dma->dma_tx =
972 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
973 						 &sig, &master->dev,
974 						 mcspi_dma->dma_tx_ch_name);
975 
976 	if (!mcspi_dma->dma_tx) {
977 		dma_release_channel(mcspi_dma->dma_rx);
978 		mcspi_dma->dma_rx = NULL;
979 		goto no_dma;
980 	}
981 
982 	return 0;
983 
984 no_dma:
985 	dev_warn(&spi->dev, "not using DMA for McSPI\n");
986 	return -EAGAIN;
987 }
988 
989 static int omap2_mcspi_setup(struct spi_device *spi)
990 {
991 	int			ret;
992 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
993 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
994 	struct omap2_mcspi_dma	*mcspi_dma;
995 	struct omap2_mcspi_cs	*cs = spi->controller_state;
996 
997 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
998 
999 	if (!cs) {
1000 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
1001 		if (!cs)
1002 			return -ENOMEM;
1003 		cs->base = mcspi->base + spi->chip_select * 0x14;
1004 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1005 		cs->mode = 0;
1006 		cs->chconf0 = 0;
1007 		cs->chctrl0 = 0;
1008 		spi->controller_state = cs;
1009 		/* Link this to context save list */
1010 		list_add_tail(&cs->node, &ctx->cs);
1011 	}
1012 
1013 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1014 		ret = omap2_mcspi_request_dma(spi);
1015 		if (ret < 0 && ret != -EAGAIN)
1016 			return ret;
1017 	}
1018 
1019 	ret = pm_runtime_get_sync(mcspi->dev);
1020 	if (ret < 0)
1021 		return ret;
1022 
1023 	ret = omap2_mcspi_setup_transfer(spi, NULL);
1024 	pm_runtime_mark_last_busy(mcspi->dev);
1025 	pm_runtime_put_autosuspend(mcspi->dev);
1026 
1027 	return ret;
1028 }
1029 
1030 static void omap2_mcspi_cleanup(struct spi_device *spi)
1031 {
1032 	struct omap2_mcspi	*mcspi;
1033 	struct omap2_mcspi_dma	*mcspi_dma;
1034 	struct omap2_mcspi_cs	*cs;
1035 
1036 	mcspi = spi_master_get_devdata(spi->master);
1037 
1038 	if (spi->controller_state) {
1039 		/* Unlink controller state from context save list */
1040 		cs = spi->controller_state;
1041 		list_del(&cs->node);
1042 
1043 		kfree(cs);
1044 	}
1045 
1046 	if (spi->chip_select < spi->master->num_chipselect) {
1047 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1048 
1049 		if (mcspi_dma->dma_rx) {
1050 			dma_release_channel(mcspi_dma->dma_rx);
1051 			mcspi_dma->dma_rx = NULL;
1052 		}
1053 		if (mcspi_dma->dma_tx) {
1054 			dma_release_channel(mcspi_dma->dma_tx);
1055 			mcspi_dma->dma_tx = NULL;
1056 		}
1057 	}
1058 }
1059 
1060 static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
1061 {
1062 
1063 	/* We only enable one channel at a time -- the one whose message is
1064 	 * -- although this controller would gladly
1065 	 * arbitrate among multiple channels.  This corresponds to "single
1066 	 * channel" master mode.  As a side effect, we need to manage the
1067 	 * chipselect with the FORCE bit ... CS != channel enable.
1068 	 */
1069 
1070 	struct spi_device		*spi;
1071 	struct spi_transfer		*t = NULL;
1072 	struct spi_master		*master;
1073 	struct omap2_mcspi_dma		*mcspi_dma;
1074 	int				cs_active = 0;
1075 	struct omap2_mcspi_cs		*cs;
1076 	struct omap2_mcspi_device_config *cd;
1077 	int				par_override = 0;
1078 	int				status = 0;
1079 	u32				chconf;
1080 
1081 	spi = m->spi;
1082 	master = spi->master;
1083 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1084 	cs = spi->controller_state;
1085 	cd = spi->controller_data;
1086 
1087 	/*
1088 	 * The slave driver could have changed spi->mode in which case
1089 	 * it will be different from cs->mode (the current hardware setup).
1090 	 * If so, set par_override (even though its not a parity issue) so
1091 	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1092 	 * with the correct mode on the first iteration of the loop below.
1093 	 */
1094 	if (spi->mode != cs->mode)
1095 		par_override = 1;
1096 
1097 	omap2_mcspi_set_enable(spi, 0);
1098 	list_for_each_entry(t, &m->transfers, transfer_list) {
1099 		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
1100 			status = -EINVAL;
1101 			break;
1102 		}
1103 		if (par_override ||
1104 		    (t->speed_hz != spi->max_speed_hz) ||
1105 		    (t->bits_per_word != spi->bits_per_word)) {
1106 			par_override = 1;
1107 			status = omap2_mcspi_setup_transfer(spi, t);
1108 			if (status < 0)
1109 				break;
1110 			if (t->speed_hz == spi->max_speed_hz &&
1111 			    t->bits_per_word == spi->bits_per_word)
1112 				par_override = 0;
1113 		}
1114 		if (cd && cd->cs_per_word) {
1115 			chconf = mcspi->ctx.modulctrl;
1116 			chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1117 			mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1118 			mcspi->ctx.modulctrl =
1119 				mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1120 		}
1121 
1122 
1123 		if (!cs_active) {
1124 			omap2_mcspi_force_cs(spi, 1);
1125 			cs_active = 1;
1126 		}
1127 
1128 		chconf = mcspi_cached_chconf0(spi);
1129 		chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1130 		chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1131 
1132 		if (t->tx_buf == NULL)
1133 			chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1134 		else if (t->rx_buf == NULL)
1135 			chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1136 
1137 		if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1138 			/* Turbo mode is for more than one word */
1139 			if (t->len > ((cs->word_len + 7) >> 3))
1140 				chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1141 		}
1142 
1143 		mcspi_write_chconf0(spi, chconf);
1144 
1145 		if (t->len) {
1146 			unsigned	count;
1147 
1148 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1149 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1150 				omap2_mcspi_set_fifo(spi, t, 1);
1151 
1152 			omap2_mcspi_set_enable(spi, 1);
1153 
1154 			/* RX_ONLY mode needs dummy data in TX reg */
1155 			if (t->tx_buf == NULL)
1156 				writel_relaxed(0, cs->base
1157 						+ OMAP2_MCSPI_TX0);
1158 
1159 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1160 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1161 				count = omap2_mcspi_txrx_dma(spi, t);
1162 			else
1163 				count = omap2_mcspi_txrx_pio(spi, t);
1164 			m->actual_length += count;
1165 
1166 			if (count != t->len) {
1167 				status = -EIO;
1168 				break;
1169 			}
1170 		}
1171 
1172 		if (t->delay_usecs)
1173 			udelay(t->delay_usecs);
1174 
1175 		/* ignore the "leave it on after last xfer" hint */
1176 		if (t->cs_change) {
1177 			omap2_mcspi_force_cs(spi, 0);
1178 			cs_active = 0;
1179 		}
1180 
1181 		omap2_mcspi_set_enable(spi, 0);
1182 
1183 		if (mcspi->fifo_depth > 0)
1184 			omap2_mcspi_set_fifo(spi, t, 0);
1185 	}
1186 	/* Restore defaults if they were overriden */
1187 	if (par_override) {
1188 		par_override = 0;
1189 		status = omap2_mcspi_setup_transfer(spi, NULL);
1190 	}
1191 
1192 	if (cs_active)
1193 		omap2_mcspi_force_cs(spi, 0);
1194 
1195 	if (cd && cd->cs_per_word) {
1196 		chconf = mcspi->ctx.modulctrl;
1197 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1198 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1199 		mcspi->ctx.modulctrl =
1200 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1201 	}
1202 
1203 	omap2_mcspi_set_enable(spi, 0);
1204 
1205 	if (mcspi->fifo_depth > 0 && t)
1206 		omap2_mcspi_set_fifo(spi, t, 0);
1207 
1208 	m->status = status;
1209 }
1210 
1211 static int omap2_mcspi_transfer_one_message(struct spi_master *master,
1212 		struct spi_message *m)
1213 {
1214 	struct spi_device	*spi;
1215 	struct omap2_mcspi	*mcspi;
1216 	struct omap2_mcspi_dma	*mcspi_dma;
1217 	struct spi_transfer	*t;
1218 
1219 	spi = m->spi;
1220 	mcspi = spi_master_get_devdata(master);
1221 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1222 	m->actual_length = 0;
1223 	m->status = 0;
1224 
1225 	list_for_each_entry(t, &m->transfers, transfer_list) {
1226 		const void	*tx_buf = t->tx_buf;
1227 		void		*rx_buf = t->rx_buf;
1228 		unsigned	len = t->len;
1229 
1230 		if ((len && !(rx_buf || tx_buf))) {
1231 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1232 					t->speed_hz,
1233 					len,
1234 					tx_buf ? "tx" : "",
1235 					rx_buf ? "rx" : "",
1236 					t->bits_per_word);
1237 			return -EINVAL;
1238 		}
1239 
1240 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1241 			continue;
1242 
1243 		if (mcspi_dma->dma_tx && tx_buf != NULL) {
1244 			t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1245 					len, DMA_TO_DEVICE);
1246 			if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1247 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1248 						'T', len);
1249 				return -EINVAL;
1250 			}
1251 		}
1252 		if (mcspi_dma->dma_rx && rx_buf != NULL) {
1253 			t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1254 					DMA_FROM_DEVICE);
1255 			if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1256 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1257 						'R', len);
1258 				if (tx_buf != NULL)
1259 					dma_unmap_single(mcspi->dev, t->tx_dma,
1260 							len, DMA_TO_DEVICE);
1261 				return -EINVAL;
1262 			}
1263 		}
1264 	}
1265 
1266 	omap2_mcspi_work(mcspi, m);
1267 	spi_finalize_current_message(master);
1268 	return 0;
1269 }
1270 
1271 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1272 {
1273 	struct spi_master	*master = mcspi->master;
1274 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1275 	int			ret = 0;
1276 
1277 	ret = pm_runtime_get_sync(mcspi->dev);
1278 	if (ret < 0)
1279 		return ret;
1280 
1281 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1282 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1283 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1284 
1285 	omap2_mcspi_set_master_mode(master);
1286 	pm_runtime_mark_last_busy(mcspi->dev);
1287 	pm_runtime_put_autosuspend(mcspi->dev);
1288 	return 0;
1289 }
1290 
1291 static int omap_mcspi_runtime_resume(struct device *dev)
1292 {
1293 	struct omap2_mcspi	*mcspi;
1294 	struct spi_master	*master;
1295 
1296 	master = dev_get_drvdata(dev);
1297 	mcspi = spi_master_get_devdata(master);
1298 	omap2_mcspi_restore_ctx(mcspi);
1299 
1300 	return 0;
1301 }
1302 
1303 static struct omap2_mcspi_platform_config omap2_pdata = {
1304 	.regs_offset = 0,
1305 };
1306 
1307 static struct omap2_mcspi_platform_config omap4_pdata = {
1308 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1309 };
1310 
1311 static const struct of_device_id omap_mcspi_of_match[] = {
1312 	{
1313 		.compatible = "ti,omap2-mcspi",
1314 		.data = &omap2_pdata,
1315 	},
1316 	{
1317 		.compatible = "ti,omap4-mcspi",
1318 		.data = &omap4_pdata,
1319 	},
1320 	{ },
1321 };
1322 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1323 
1324 static int omap2_mcspi_probe(struct platform_device *pdev)
1325 {
1326 	struct spi_master	*master;
1327 	const struct omap2_mcspi_platform_config *pdata;
1328 	struct omap2_mcspi	*mcspi;
1329 	struct resource		*r;
1330 	int			status = 0, i;
1331 	u32			regs_offset = 0;
1332 	static int		bus_num = 1;
1333 	struct device_node	*node = pdev->dev.of_node;
1334 	const struct of_device_id *match;
1335 
1336 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1337 	if (master == NULL) {
1338 		dev_dbg(&pdev->dev, "master allocation failed\n");
1339 		return -ENOMEM;
1340 	}
1341 
1342 	/* the spi->mode bits understood by this driver: */
1343 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1344 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1345 	master->setup = omap2_mcspi_setup;
1346 	master->auto_runtime_pm = true;
1347 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
1348 	master->cleanup = omap2_mcspi_cleanup;
1349 	master->dev.of_node = node;
1350 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1351 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1352 
1353 	platform_set_drvdata(pdev, master);
1354 
1355 	mcspi = spi_master_get_devdata(master);
1356 	mcspi->master = master;
1357 
1358 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1359 	if (match) {
1360 		u32 num_cs = 1; /* default number of chipselect */
1361 		pdata = match->data;
1362 
1363 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1364 		master->num_chipselect = num_cs;
1365 		master->bus_num = bus_num++;
1366 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1367 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1368 	} else {
1369 		pdata = dev_get_platdata(&pdev->dev);
1370 		master->num_chipselect = pdata->num_cs;
1371 		if (pdev->id != -1)
1372 			master->bus_num = pdev->id;
1373 		mcspi->pin_dir = pdata->pin_dir;
1374 	}
1375 	regs_offset = pdata->regs_offset;
1376 
1377 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1378 	if (r == NULL) {
1379 		status = -ENODEV;
1380 		goto free_master;
1381 	}
1382 
1383 	r->start += regs_offset;
1384 	r->end += regs_offset;
1385 	mcspi->phys = r->start;
1386 
1387 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1388 	if (IS_ERR(mcspi->base)) {
1389 		status = PTR_ERR(mcspi->base);
1390 		goto free_master;
1391 	}
1392 
1393 	mcspi->dev = &pdev->dev;
1394 
1395 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1396 
1397 	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1398 					   sizeof(struct omap2_mcspi_dma),
1399 					   GFP_KERNEL);
1400 	if (mcspi->dma_channels == NULL) {
1401 		status = -ENOMEM;
1402 		goto free_master;
1403 	}
1404 
1405 	for (i = 0; i < master->num_chipselect; i++) {
1406 		char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1407 		char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1408 		struct resource *dma_res;
1409 
1410 		sprintf(dma_rx_ch_name, "rx%d", i);
1411 		if (!pdev->dev.of_node) {
1412 			dma_res =
1413 				platform_get_resource_byname(pdev,
1414 							     IORESOURCE_DMA,
1415 							     dma_rx_ch_name);
1416 			if (!dma_res) {
1417 				dev_dbg(&pdev->dev,
1418 					"cannot get DMA RX channel\n");
1419 				status = -ENODEV;
1420 				break;
1421 			}
1422 
1423 			mcspi->dma_channels[i].dma_rx_sync_dev =
1424 				dma_res->start;
1425 		}
1426 		sprintf(dma_tx_ch_name, "tx%d", i);
1427 		if (!pdev->dev.of_node) {
1428 			dma_res =
1429 				platform_get_resource_byname(pdev,
1430 							     IORESOURCE_DMA,
1431 							     dma_tx_ch_name);
1432 			if (!dma_res) {
1433 				dev_dbg(&pdev->dev,
1434 					"cannot get DMA TX channel\n");
1435 				status = -ENODEV;
1436 				break;
1437 			}
1438 
1439 			mcspi->dma_channels[i].dma_tx_sync_dev =
1440 				dma_res->start;
1441 		}
1442 	}
1443 
1444 	if (status < 0)
1445 		goto free_master;
1446 
1447 	pm_runtime_use_autosuspend(&pdev->dev);
1448 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1449 	pm_runtime_enable(&pdev->dev);
1450 
1451 	status = omap2_mcspi_master_setup(mcspi);
1452 	if (status < 0)
1453 		goto disable_pm;
1454 
1455 	status = devm_spi_register_master(&pdev->dev, master);
1456 	if (status < 0)
1457 		goto disable_pm;
1458 
1459 	return status;
1460 
1461 disable_pm:
1462 	pm_runtime_disable(&pdev->dev);
1463 free_master:
1464 	spi_master_put(master);
1465 	return status;
1466 }
1467 
1468 static int omap2_mcspi_remove(struct platform_device *pdev)
1469 {
1470 	struct spi_master *master = platform_get_drvdata(pdev);
1471 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1472 
1473 	pm_runtime_put_sync(mcspi->dev);
1474 	pm_runtime_disable(&pdev->dev);
1475 
1476 	return 0;
1477 }
1478 
1479 /* work with hotplug and coldplug */
1480 MODULE_ALIAS("platform:omap2_mcspi");
1481 
1482 #ifdef	CONFIG_SUSPEND
1483 /*
1484  * When SPI wake up from off-mode, CS is in activate state. If it was in
1485  * unactive state when driver was suspend, then force it to unactive state at
1486  * wake up.
1487  */
1488 static int omap2_mcspi_resume(struct device *dev)
1489 {
1490 	struct spi_master	*master = dev_get_drvdata(dev);
1491 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1492 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1493 	struct omap2_mcspi_cs	*cs;
1494 
1495 	pm_runtime_get_sync(mcspi->dev);
1496 	list_for_each_entry(cs, &ctx->cs, node) {
1497 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1498 			/*
1499 			 * We need to toggle CS state for OMAP take this
1500 			 * change in account.
1501 			 */
1502 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1503 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1504 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1505 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1506 		}
1507 	}
1508 	pm_runtime_mark_last_busy(mcspi->dev);
1509 	pm_runtime_put_autosuspend(mcspi->dev);
1510 	return 0;
1511 }
1512 #else
1513 #define	omap2_mcspi_resume	NULL
1514 #endif
1515 
1516 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1517 	.resume = omap2_mcspi_resume,
1518 	.runtime_resume	= omap_mcspi_runtime_resume,
1519 };
1520 
1521 static struct platform_driver omap2_mcspi_driver = {
1522 	.driver = {
1523 		.name =		"omap2_mcspi",
1524 		.owner =	THIS_MODULE,
1525 		.pm =		&omap2_mcspi_pm_ops,
1526 		.of_match_table = omap_mcspi_of_match,
1527 	},
1528 	.probe =	omap2_mcspi_probe,
1529 	.remove =	omap2_mcspi_remove,
1530 };
1531 
1532 module_platform_driver(omap2_mcspi_driver);
1533 MODULE_LICENSE("GPL");
1534