xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision 275876e2)
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 	else
333 		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
334 
335 	mcspi_write_chconf0(spi, chconf);
336 	mcspi->fifo_depth = 0;
337 }
338 
339 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
340 {
341 	struct spi_master	*spi_cntrl = mcspi->master;
342 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
343 	struct omap2_mcspi_cs	*cs;
344 
345 	/* McSPI: context restore */
346 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
347 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
348 
349 	list_for_each_entry(cs, &ctx->cs, node)
350 		writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
351 }
352 
353 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
354 {
355 	unsigned long timeout;
356 
357 	timeout = jiffies + msecs_to_jiffies(1000);
358 	while (!(readl_relaxed(reg) & bit)) {
359 		if (time_after(jiffies, timeout)) {
360 			if (!(readl_relaxed(reg) & bit))
361 				return -ETIMEDOUT;
362 			else
363 				return 0;
364 		}
365 		cpu_relax();
366 	}
367 	return 0;
368 }
369 
370 static void omap2_mcspi_rx_callback(void *data)
371 {
372 	struct spi_device *spi = data;
373 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
374 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
375 
376 	/* We must disable the DMA RX request */
377 	omap2_mcspi_set_dma_req(spi, 1, 0);
378 
379 	complete(&mcspi_dma->dma_rx_completion);
380 }
381 
382 static void omap2_mcspi_tx_callback(void *data)
383 {
384 	struct spi_device *spi = data;
385 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
386 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
387 
388 	/* We must disable the DMA TX request */
389 	omap2_mcspi_set_dma_req(spi, 0, 0);
390 
391 	complete(&mcspi_dma->dma_tx_completion);
392 }
393 
394 static void omap2_mcspi_tx_dma(struct spi_device *spi,
395 				struct spi_transfer *xfer,
396 				struct dma_slave_config cfg)
397 {
398 	struct omap2_mcspi	*mcspi;
399 	struct omap2_mcspi_dma  *mcspi_dma;
400 	unsigned int		count;
401 
402 	mcspi = spi_master_get_devdata(spi->master);
403 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
404 	count = xfer->len;
405 
406 	if (mcspi_dma->dma_tx) {
407 		struct dma_async_tx_descriptor *tx;
408 		struct scatterlist sg;
409 
410 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
411 
412 		sg_init_table(&sg, 1);
413 		sg_dma_address(&sg) = xfer->tx_dma;
414 		sg_dma_len(&sg) = xfer->len;
415 
416 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
417 		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
418 		if (tx) {
419 			tx->callback = omap2_mcspi_tx_callback;
420 			tx->callback_param = spi;
421 			dmaengine_submit(tx);
422 		} else {
423 			/* FIXME: fall back to PIO? */
424 		}
425 	}
426 	dma_async_issue_pending(mcspi_dma->dma_tx);
427 	omap2_mcspi_set_dma_req(spi, 0, 1);
428 
429 }
430 
431 static unsigned
432 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
433 				struct dma_slave_config cfg,
434 				unsigned es)
435 {
436 	struct omap2_mcspi	*mcspi;
437 	struct omap2_mcspi_dma  *mcspi_dma;
438 	unsigned int		count, dma_count;
439 	u32			l;
440 	int			elements = 0;
441 	int			word_len, element_count;
442 	struct omap2_mcspi_cs	*cs = spi->controller_state;
443 	mcspi = spi_master_get_devdata(spi->master);
444 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
445 	count = xfer->len;
446 	dma_count = xfer->len;
447 
448 	if (mcspi->fifo_depth == 0)
449 		dma_count -= es;
450 
451 	word_len = cs->word_len;
452 	l = mcspi_cached_chconf0(spi);
453 
454 	if (word_len <= 8)
455 		element_count = count;
456 	else if (word_len <= 16)
457 		element_count = count >> 1;
458 	else /* word_len <= 32 */
459 		element_count = count >> 2;
460 
461 	if (mcspi_dma->dma_rx) {
462 		struct dma_async_tx_descriptor *tx;
463 		struct scatterlist sg;
464 
465 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
466 
467 		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
468 			dma_count -= es;
469 
470 		sg_init_table(&sg, 1);
471 		sg_dma_address(&sg) = xfer->rx_dma;
472 		sg_dma_len(&sg) = dma_count;
473 
474 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
475 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
476 				DMA_CTRL_ACK);
477 		if (tx) {
478 			tx->callback = omap2_mcspi_rx_callback;
479 			tx->callback_param = spi;
480 			dmaengine_submit(tx);
481 		} else {
482 				/* FIXME: fall back to PIO? */
483 		}
484 	}
485 
486 	dma_async_issue_pending(mcspi_dma->dma_rx);
487 	omap2_mcspi_set_dma_req(spi, 1, 1);
488 
489 	wait_for_completion(&mcspi_dma->dma_rx_completion);
490 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
491 			 DMA_FROM_DEVICE);
492 
493 	if (mcspi->fifo_depth > 0)
494 		return count;
495 
496 	omap2_mcspi_set_enable(spi, 0);
497 
498 	elements = element_count - 1;
499 
500 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
501 		elements--;
502 
503 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
504 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
505 			u32 w;
506 
507 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
508 			if (word_len <= 8)
509 				((u8 *)xfer->rx_buf)[elements++] = w;
510 			else if (word_len <= 16)
511 				((u16 *)xfer->rx_buf)[elements++] = w;
512 			else /* word_len <= 32 */
513 				((u32 *)xfer->rx_buf)[elements++] = w;
514 		} else {
515 			int bytes_per_word = mcspi_bytes_per_word(word_len);
516 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
517 			count -= (bytes_per_word << 1);
518 			omap2_mcspi_set_enable(spi, 1);
519 			return count;
520 		}
521 	}
522 	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
523 				& OMAP2_MCSPI_CHSTAT_RXS)) {
524 		u32 w;
525 
526 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
527 		if (word_len <= 8)
528 			((u8 *)xfer->rx_buf)[elements] = w;
529 		else if (word_len <= 16)
530 			((u16 *)xfer->rx_buf)[elements] = w;
531 		else /* word_len <= 32 */
532 			((u32 *)xfer->rx_buf)[elements] = w;
533 	} else {
534 		dev_err(&spi->dev, "DMA RX last word empty\n");
535 		count -= mcspi_bytes_per_word(word_len);
536 	}
537 	omap2_mcspi_set_enable(spi, 1);
538 	return count;
539 }
540 
541 static unsigned
542 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
543 {
544 	struct omap2_mcspi	*mcspi;
545 	struct omap2_mcspi_cs	*cs = spi->controller_state;
546 	struct omap2_mcspi_dma  *mcspi_dma;
547 	unsigned int		count;
548 	u32			l;
549 	u8			*rx;
550 	const u8		*tx;
551 	struct dma_slave_config	cfg;
552 	enum dma_slave_buswidth width;
553 	unsigned es;
554 	u32			burst;
555 	void __iomem		*chstat_reg;
556 	void __iomem            *irqstat_reg;
557 	int			wait_res;
558 
559 	mcspi = spi_master_get_devdata(spi->master);
560 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
561 	l = mcspi_cached_chconf0(spi);
562 
563 
564 	if (cs->word_len <= 8) {
565 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
566 		es = 1;
567 	} else if (cs->word_len <= 16) {
568 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
569 		es = 2;
570 	} else {
571 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
572 		es = 4;
573 	}
574 
575 	count = xfer->len;
576 	burst = 1;
577 
578 	if (mcspi->fifo_depth > 0) {
579 		if (count > mcspi->fifo_depth)
580 			burst = mcspi->fifo_depth / es;
581 		else
582 			burst = count / es;
583 	}
584 
585 	memset(&cfg, 0, sizeof(cfg));
586 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
587 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
588 	cfg.src_addr_width = width;
589 	cfg.dst_addr_width = width;
590 	cfg.src_maxburst = burst;
591 	cfg.dst_maxburst = burst;
592 
593 	rx = xfer->rx_buf;
594 	tx = xfer->tx_buf;
595 
596 	if (tx != NULL)
597 		omap2_mcspi_tx_dma(spi, xfer, cfg);
598 
599 	if (rx != NULL)
600 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
601 
602 	if (tx != NULL) {
603 		wait_for_completion(&mcspi_dma->dma_tx_completion);
604 		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
605 				 DMA_TO_DEVICE);
606 
607 		if (mcspi->fifo_depth > 0) {
608 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
609 
610 			if (mcspi_wait_for_reg_bit(irqstat_reg,
611 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
612 				dev_err(&spi->dev, "EOW timed out\n");
613 
614 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
615 					OMAP2_MCSPI_IRQSTATUS_EOW);
616 		}
617 
618 		/* for TX_ONLY mode, be sure all words have shifted out */
619 		if (rx == NULL) {
620 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
621 			if (mcspi->fifo_depth > 0) {
622 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
623 						OMAP2_MCSPI_CHSTAT_TXFFE);
624 				if (wait_res < 0)
625 					dev_err(&spi->dev, "TXFFE timed out\n");
626 			} else {
627 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
628 						OMAP2_MCSPI_CHSTAT_TXS);
629 				if (wait_res < 0)
630 					dev_err(&spi->dev, "TXS timed out\n");
631 			}
632 			if (wait_res >= 0 &&
633 				(mcspi_wait_for_reg_bit(chstat_reg,
634 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
635 				dev_err(&spi->dev, "EOT timed out\n");
636 		}
637 	}
638 	return count;
639 }
640 
641 static unsigned
642 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
643 {
644 	struct omap2_mcspi	*mcspi;
645 	struct omap2_mcspi_cs	*cs = spi->controller_state;
646 	unsigned int		count, c;
647 	u32			l;
648 	void __iomem		*base = cs->base;
649 	void __iomem		*tx_reg;
650 	void __iomem		*rx_reg;
651 	void __iomem		*chstat_reg;
652 	int			word_len;
653 
654 	mcspi = spi_master_get_devdata(spi->master);
655 	count = xfer->len;
656 	c = count;
657 	word_len = cs->word_len;
658 
659 	l = mcspi_cached_chconf0(spi);
660 
661 	/* We store the pre-calculated register addresses on stack to speed
662 	 * up the transfer loop. */
663 	tx_reg		= base + OMAP2_MCSPI_TX0;
664 	rx_reg		= base + OMAP2_MCSPI_RX0;
665 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
666 
667 	if (c < (word_len>>3))
668 		return 0;
669 
670 	if (word_len <= 8) {
671 		u8		*rx;
672 		const u8	*tx;
673 
674 		rx = xfer->rx_buf;
675 		tx = xfer->tx_buf;
676 
677 		do {
678 			c -= 1;
679 			if (tx != NULL) {
680 				if (mcspi_wait_for_reg_bit(chstat_reg,
681 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
682 					dev_err(&spi->dev, "TXS timed out\n");
683 					goto out;
684 				}
685 				dev_vdbg(&spi->dev, "write-%d %02x\n",
686 						word_len, *tx);
687 				writel_relaxed(*tx++, tx_reg);
688 			}
689 			if (rx != NULL) {
690 				if (mcspi_wait_for_reg_bit(chstat_reg,
691 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
692 					dev_err(&spi->dev, "RXS timed out\n");
693 					goto out;
694 				}
695 
696 				if (c == 1 && tx == NULL &&
697 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
698 					omap2_mcspi_set_enable(spi, 0);
699 					*rx++ = readl_relaxed(rx_reg);
700 					dev_vdbg(&spi->dev, "read-%d %02x\n",
701 						    word_len, *(rx - 1));
702 					if (mcspi_wait_for_reg_bit(chstat_reg,
703 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
704 						dev_err(&spi->dev,
705 							"RXS timed out\n");
706 						goto out;
707 					}
708 					c = 0;
709 				} else if (c == 0 && tx == NULL) {
710 					omap2_mcspi_set_enable(spi, 0);
711 				}
712 
713 				*rx++ = readl_relaxed(rx_reg);
714 				dev_vdbg(&spi->dev, "read-%d %02x\n",
715 						word_len, *(rx - 1));
716 			}
717 		} while (c);
718 	} else if (word_len <= 16) {
719 		u16		*rx;
720 		const u16	*tx;
721 
722 		rx = xfer->rx_buf;
723 		tx = xfer->tx_buf;
724 		do {
725 			c -= 2;
726 			if (tx != NULL) {
727 				if (mcspi_wait_for_reg_bit(chstat_reg,
728 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
729 					dev_err(&spi->dev, "TXS timed out\n");
730 					goto out;
731 				}
732 				dev_vdbg(&spi->dev, "write-%d %04x\n",
733 						word_len, *tx);
734 				writel_relaxed(*tx++, tx_reg);
735 			}
736 			if (rx != NULL) {
737 				if (mcspi_wait_for_reg_bit(chstat_reg,
738 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
739 					dev_err(&spi->dev, "RXS timed out\n");
740 					goto out;
741 				}
742 
743 				if (c == 2 && tx == NULL &&
744 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
745 					omap2_mcspi_set_enable(spi, 0);
746 					*rx++ = readl_relaxed(rx_reg);
747 					dev_vdbg(&spi->dev, "read-%d %04x\n",
748 						    word_len, *(rx - 1));
749 					if (mcspi_wait_for_reg_bit(chstat_reg,
750 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
751 						dev_err(&spi->dev,
752 							"RXS timed out\n");
753 						goto out;
754 					}
755 					c = 0;
756 				} else if (c == 0 && tx == NULL) {
757 					omap2_mcspi_set_enable(spi, 0);
758 				}
759 
760 				*rx++ = readl_relaxed(rx_reg);
761 				dev_vdbg(&spi->dev, "read-%d %04x\n",
762 						word_len, *(rx - 1));
763 			}
764 		} while (c >= 2);
765 	} else if (word_len <= 32) {
766 		u32		*rx;
767 		const u32	*tx;
768 
769 		rx = xfer->rx_buf;
770 		tx = xfer->tx_buf;
771 		do {
772 			c -= 4;
773 			if (tx != NULL) {
774 				if (mcspi_wait_for_reg_bit(chstat_reg,
775 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
776 					dev_err(&spi->dev, "TXS timed out\n");
777 					goto out;
778 				}
779 				dev_vdbg(&spi->dev, "write-%d %08x\n",
780 						word_len, *tx);
781 				writel_relaxed(*tx++, tx_reg);
782 			}
783 			if (rx != NULL) {
784 				if (mcspi_wait_for_reg_bit(chstat_reg,
785 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
786 					dev_err(&spi->dev, "RXS timed out\n");
787 					goto out;
788 				}
789 
790 				if (c == 4 && tx == NULL &&
791 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
792 					omap2_mcspi_set_enable(spi, 0);
793 					*rx++ = readl_relaxed(rx_reg);
794 					dev_vdbg(&spi->dev, "read-%d %08x\n",
795 						    word_len, *(rx - 1));
796 					if (mcspi_wait_for_reg_bit(chstat_reg,
797 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
798 						dev_err(&spi->dev,
799 							"RXS timed out\n");
800 						goto out;
801 					}
802 					c = 0;
803 				} else if (c == 0 && tx == NULL) {
804 					omap2_mcspi_set_enable(spi, 0);
805 				}
806 
807 				*rx++ = readl_relaxed(rx_reg);
808 				dev_vdbg(&spi->dev, "read-%d %08x\n",
809 						word_len, *(rx - 1));
810 			}
811 		} while (c >= 4);
812 	}
813 
814 	/* for TX_ONLY mode, be sure all words have shifted out */
815 	if (xfer->rx_buf == NULL) {
816 		if (mcspi_wait_for_reg_bit(chstat_reg,
817 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
818 			dev_err(&spi->dev, "TXS timed out\n");
819 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
820 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
821 			dev_err(&spi->dev, "EOT timed out\n");
822 
823 		/* disable chan to purge rx datas received in TX_ONLY transfer,
824 		 * otherwise these rx datas will affect the direct following
825 		 * RX_ONLY transfer.
826 		 */
827 		omap2_mcspi_set_enable(spi, 0);
828 	}
829 out:
830 	omap2_mcspi_set_enable(spi, 1);
831 	return count - c;
832 }
833 
834 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
835 {
836 	u32 div;
837 
838 	for (div = 0; div < 15; div++)
839 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
840 			return div;
841 
842 	return 15;
843 }
844 
845 /* called only when no transfer is active to this device */
846 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
847 		struct spi_transfer *t)
848 {
849 	struct omap2_mcspi_cs *cs = spi->controller_state;
850 	struct omap2_mcspi *mcspi;
851 	struct spi_master *spi_cntrl;
852 	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
853 	u8 word_len = spi->bits_per_word;
854 	u32 speed_hz = spi->max_speed_hz;
855 
856 	mcspi = spi_master_get_devdata(spi->master);
857 	spi_cntrl = mcspi->master;
858 
859 	if (t != NULL && t->bits_per_word)
860 		word_len = t->bits_per_word;
861 
862 	cs->word_len = word_len;
863 
864 	if (t && t->speed_hz)
865 		speed_hz = t->speed_hz;
866 
867 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
868 	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
869 		clkd = omap2_mcspi_calc_divisor(speed_hz);
870 		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
871 		clkg = 0;
872 	} else {
873 		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
874 		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
875 		clkd = (div - 1) & 0xf;
876 		extclk = (div - 1) >> 4;
877 		clkg = OMAP2_MCSPI_CHCONF_CLKG;
878 	}
879 
880 	l = mcspi_cached_chconf0(spi);
881 
882 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
883 	 * REVISIT: this controller could support SPI_3WIRE mode.
884 	 */
885 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
886 		l &= ~OMAP2_MCSPI_CHCONF_IS;
887 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
888 		l |= OMAP2_MCSPI_CHCONF_DPE0;
889 	} else {
890 		l |= OMAP2_MCSPI_CHCONF_IS;
891 		l |= OMAP2_MCSPI_CHCONF_DPE1;
892 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
893 	}
894 
895 	/* wordlength */
896 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
897 	l |= (word_len - 1) << 7;
898 
899 	/* set chipselect polarity; manage with FORCE */
900 	if (!(spi->mode & SPI_CS_HIGH))
901 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
902 	else
903 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
904 
905 	/* set clock divisor */
906 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
907 	l |= clkd << 2;
908 
909 	/* set clock granularity */
910 	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
911 	l |= clkg;
912 	if (clkg) {
913 		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
914 		cs->chctrl0 |= extclk << 8;
915 		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
916 	}
917 
918 	/* set SPI mode 0..3 */
919 	if (spi->mode & SPI_CPOL)
920 		l |= OMAP2_MCSPI_CHCONF_POL;
921 	else
922 		l &= ~OMAP2_MCSPI_CHCONF_POL;
923 	if (spi->mode & SPI_CPHA)
924 		l |= OMAP2_MCSPI_CHCONF_PHA;
925 	else
926 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
927 
928 	mcspi_write_chconf0(spi, l);
929 
930 	cs->mode = spi->mode;
931 
932 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
933 			speed_hz,
934 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
935 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
936 
937 	return 0;
938 }
939 
940 /*
941  * Note that we currently allow DMA only if we get a channel
942  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
943  */
944 static int omap2_mcspi_request_dma(struct spi_device *spi)
945 {
946 	struct spi_master	*master = spi->master;
947 	struct omap2_mcspi	*mcspi;
948 	struct omap2_mcspi_dma	*mcspi_dma;
949 	dma_cap_mask_t mask;
950 	unsigned sig;
951 
952 	mcspi = spi_master_get_devdata(master);
953 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
954 
955 	init_completion(&mcspi_dma->dma_rx_completion);
956 	init_completion(&mcspi_dma->dma_tx_completion);
957 
958 	dma_cap_zero(mask);
959 	dma_cap_set(DMA_SLAVE, mask);
960 	sig = mcspi_dma->dma_rx_sync_dev;
961 
962 	mcspi_dma->dma_rx =
963 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
964 						 &sig, &master->dev,
965 						 mcspi_dma->dma_rx_ch_name);
966 	if (!mcspi_dma->dma_rx)
967 		goto no_dma;
968 
969 	sig = mcspi_dma->dma_tx_sync_dev;
970 	mcspi_dma->dma_tx =
971 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
972 						 &sig, &master->dev,
973 						 mcspi_dma->dma_tx_ch_name);
974 
975 	if (!mcspi_dma->dma_tx) {
976 		dma_release_channel(mcspi_dma->dma_rx);
977 		mcspi_dma->dma_rx = NULL;
978 		goto no_dma;
979 	}
980 
981 	return 0;
982 
983 no_dma:
984 	dev_warn(&spi->dev, "not using DMA for McSPI\n");
985 	return -EAGAIN;
986 }
987 
988 static int omap2_mcspi_setup(struct spi_device *spi)
989 {
990 	int			ret;
991 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
992 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
993 	struct omap2_mcspi_dma	*mcspi_dma;
994 	struct omap2_mcspi_cs	*cs = spi->controller_state;
995 
996 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
997 
998 	if (!cs) {
999 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
1000 		if (!cs)
1001 			return -ENOMEM;
1002 		cs->base = mcspi->base + spi->chip_select * 0x14;
1003 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1004 		cs->mode = 0;
1005 		cs->chconf0 = 0;
1006 		cs->chctrl0 = 0;
1007 		spi->controller_state = cs;
1008 		/* Link this to context save list */
1009 		list_add_tail(&cs->node, &ctx->cs);
1010 	}
1011 
1012 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1013 		ret = omap2_mcspi_request_dma(spi);
1014 		if (ret < 0 && ret != -EAGAIN)
1015 			return ret;
1016 	}
1017 
1018 	ret = pm_runtime_get_sync(mcspi->dev);
1019 	if (ret < 0)
1020 		return ret;
1021 
1022 	ret = omap2_mcspi_setup_transfer(spi, NULL);
1023 	pm_runtime_mark_last_busy(mcspi->dev);
1024 	pm_runtime_put_autosuspend(mcspi->dev);
1025 
1026 	return ret;
1027 }
1028 
1029 static void omap2_mcspi_cleanup(struct spi_device *spi)
1030 {
1031 	struct omap2_mcspi	*mcspi;
1032 	struct omap2_mcspi_dma	*mcspi_dma;
1033 	struct omap2_mcspi_cs	*cs;
1034 
1035 	mcspi = spi_master_get_devdata(spi->master);
1036 
1037 	if (spi->controller_state) {
1038 		/* Unlink controller state from context save list */
1039 		cs = spi->controller_state;
1040 		list_del(&cs->node);
1041 
1042 		kfree(cs);
1043 	}
1044 
1045 	if (spi->chip_select < spi->master->num_chipselect) {
1046 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1047 
1048 		if (mcspi_dma->dma_rx) {
1049 			dma_release_channel(mcspi_dma->dma_rx);
1050 			mcspi_dma->dma_rx = NULL;
1051 		}
1052 		if (mcspi_dma->dma_tx) {
1053 			dma_release_channel(mcspi_dma->dma_tx);
1054 			mcspi_dma->dma_tx = NULL;
1055 		}
1056 	}
1057 }
1058 
1059 static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
1060 {
1061 
1062 	/* We only enable one channel at a time -- the one whose message is
1063 	 * -- although this controller would gladly
1064 	 * arbitrate among multiple channels.  This corresponds to "single
1065 	 * channel" master mode.  As a side effect, we need to manage the
1066 	 * chipselect with the FORCE bit ... CS != channel enable.
1067 	 */
1068 
1069 	struct spi_device		*spi;
1070 	struct spi_transfer		*t = NULL;
1071 	struct spi_master		*master;
1072 	struct omap2_mcspi_dma		*mcspi_dma;
1073 	int				cs_active = 0;
1074 	struct omap2_mcspi_cs		*cs;
1075 	struct omap2_mcspi_device_config *cd;
1076 	int				par_override = 0;
1077 	int				status = 0;
1078 	u32				chconf;
1079 
1080 	spi = m->spi;
1081 	master = spi->master;
1082 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1083 	cs = spi->controller_state;
1084 	cd = spi->controller_data;
1085 
1086 	/*
1087 	 * The slave driver could have changed spi->mode in which case
1088 	 * it will be different from cs->mode (the current hardware setup).
1089 	 * If so, set par_override (even though its not a parity issue) so
1090 	 * omap2_mcspi_setup_transfer will be called to configure the hardware
1091 	 * with the correct mode on the first iteration of the loop below.
1092 	 */
1093 	if (spi->mode != cs->mode)
1094 		par_override = 1;
1095 
1096 	omap2_mcspi_set_enable(spi, 0);
1097 	list_for_each_entry(t, &m->transfers, transfer_list) {
1098 		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
1099 			status = -EINVAL;
1100 			break;
1101 		}
1102 		if (par_override ||
1103 		    (t->speed_hz != spi->max_speed_hz) ||
1104 		    (t->bits_per_word != spi->bits_per_word)) {
1105 			par_override = 1;
1106 			status = omap2_mcspi_setup_transfer(spi, t);
1107 			if (status < 0)
1108 				break;
1109 			if (t->speed_hz == spi->max_speed_hz &&
1110 			    t->bits_per_word == spi->bits_per_word)
1111 				par_override = 0;
1112 		}
1113 		if (cd && cd->cs_per_word) {
1114 			chconf = mcspi->ctx.modulctrl;
1115 			chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1116 			mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1117 			mcspi->ctx.modulctrl =
1118 				mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1119 		}
1120 
1121 
1122 		if (!cs_active) {
1123 			omap2_mcspi_force_cs(spi, 1);
1124 			cs_active = 1;
1125 		}
1126 
1127 		chconf = mcspi_cached_chconf0(spi);
1128 		chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1129 		chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1130 
1131 		if (t->tx_buf == NULL)
1132 			chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1133 		else if (t->rx_buf == NULL)
1134 			chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1135 
1136 		if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1137 			/* Turbo mode is for more than one word */
1138 			if (t->len > ((cs->word_len + 7) >> 3))
1139 				chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1140 		}
1141 
1142 		mcspi_write_chconf0(spi, chconf);
1143 
1144 		if (t->len) {
1145 			unsigned	count;
1146 
1147 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1148 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1149 				omap2_mcspi_set_fifo(spi, t, 1);
1150 
1151 			omap2_mcspi_set_enable(spi, 1);
1152 
1153 			/* RX_ONLY mode needs dummy data in TX reg */
1154 			if (t->tx_buf == NULL)
1155 				writel_relaxed(0, cs->base
1156 						+ OMAP2_MCSPI_TX0);
1157 
1158 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1159 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1160 				count = omap2_mcspi_txrx_dma(spi, t);
1161 			else
1162 				count = omap2_mcspi_txrx_pio(spi, t);
1163 			m->actual_length += count;
1164 
1165 			if (count != t->len) {
1166 				status = -EIO;
1167 				break;
1168 			}
1169 		}
1170 
1171 		if (t->delay_usecs)
1172 			udelay(t->delay_usecs);
1173 
1174 		/* ignore the "leave it on after last xfer" hint */
1175 		if (t->cs_change) {
1176 			omap2_mcspi_force_cs(spi, 0);
1177 			cs_active = 0;
1178 		}
1179 
1180 		omap2_mcspi_set_enable(spi, 0);
1181 
1182 		if (mcspi->fifo_depth > 0)
1183 			omap2_mcspi_set_fifo(spi, t, 0);
1184 	}
1185 	/* Restore defaults if they were overriden */
1186 	if (par_override) {
1187 		par_override = 0;
1188 		status = omap2_mcspi_setup_transfer(spi, NULL);
1189 	}
1190 
1191 	if (cs_active)
1192 		omap2_mcspi_force_cs(spi, 0);
1193 
1194 	if (cd && cd->cs_per_word) {
1195 		chconf = mcspi->ctx.modulctrl;
1196 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1197 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1198 		mcspi->ctx.modulctrl =
1199 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1200 	}
1201 
1202 	omap2_mcspi_set_enable(spi, 0);
1203 
1204 	if (mcspi->fifo_depth > 0 && t)
1205 		omap2_mcspi_set_fifo(spi, t, 0);
1206 
1207 	m->status = status;
1208 }
1209 
1210 static int omap2_mcspi_transfer_one_message(struct spi_master *master,
1211 		struct spi_message *m)
1212 {
1213 	struct spi_device	*spi;
1214 	struct omap2_mcspi	*mcspi;
1215 	struct omap2_mcspi_dma	*mcspi_dma;
1216 	struct spi_transfer	*t;
1217 
1218 	spi = m->spi;
1219 	mcspi = spi_master_get_devdata(master);
1220 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1221 	m->actual_length = 0;
1222 	m->status = 0;
1223 
1224 	list_for_each_entry(t, &m->transfers, transfer_list) {
1225 		const void	*tx_buf = t->tx_buf;
1226 		void		*rx_buf = t->rx_buf;
1227 		unsigned	len = t->len;
1228 
1229 		if ((len && !(rx_buf || tx_buf))) {
1230 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1231 					t->speed_hz,
1232 					len,
1233 					tx_buf ? "tx" : "",
1234 					rx_buf ? "rx" : "",
1235 					t->bits_per_word);
1236 			return -EINVAL;
1237 		}
1238 
1239 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1240 			continue;
1241 
1242 		if (mcspi_dma->dma_tx && tx_buf != NULL) {
1243 			t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1244 					len, DMA_TO_DEVICE);
1245 			if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1246 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1247 						'T', len);
1248 				return -EINVAL;
1249 			}
1250 		}
1251 		if (mcspi_dma->dma_rx && rx_buf != NULL) {
1252 			t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1253 					DMA_FROM_DEVICE);
1254 			if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1255 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1256 						'R', len);
1257 				if (tx_buf != NULL)
1258 					dma_unmap_single(mcspi->dev, t->tx_dma,
1259 							len, DMA_TO_DEVICE);
1260 				return -EINVAL;
1261 			}
1262 		}
1263 	}
1264 
1265 	omap2_mcspi_work(mcspi, m);
1266 	spi_finalize_current_message(master);
1267 	return 0;
1268 }
1269 
1270 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1271 {
1272 	struct spi_master	*master = mcspi->master;
1273 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1274 	int			ret = 0;
1275 
1276 	ret = pm_runtime_get_sync(mcspi->dev);
1277 	if (ret < 0)
1278 		return ret;
1279 
1280 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1281 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1282 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1283 
1284 	omap2_mcspi_set_master_mode(master);
1285 	pm_runtime_mark_last_busy(mcspi->dev);
1286 	pm_runtime_put_autosuspend(mcspi->dev);
1287 	return 0;
1288 }
1289 
1290 static int omap_mcspi_runtime_resume(struct device *dev)
1291 {
1292 	struct omap2_mcspi	*mcspi;
1293 	struct spi_master	*master;
1294 
1295 	master = dev_get_drvdata(dev);
1296 	mcspi = spi_master_get_devdata(master);
1297 	omap2_mcspi_restore_ctx(mcspi);
1298 
1299 	return 0;
1300 }
1301 
1302 static struct omap2_mcspi_platform_config omap2_pdata = {
1303 	.regs_offset = 0,
1304 };
1305 
1306 static struct omap2_mcspi_platform_config omap4_pdata = {
1307 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1308 };
1309 
1310 static const struct of_device_id omap_mcspi_of_match[] = {
1311 	{
1312 		.compatible = "ti,omap2-mcspi",
1313 		.data = &omap2_pdata,
1314 	},
1315 	{
1316 		.compatible = "ti,omap4-mcspi",
1317 		.data = &omap4_pdata,
1318 	},
1319 	{ },
1320 };
1321 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1322 
1323 static int omap2_mcspi_probe(struct platform_device *pdev)
1324 {
1325 	struct spi_master	*master;
1326 	const struct omap2_mcspi_platform_config *pdata;
1327 	struct omap2_mcspi	*mcspi;
1328 	struct resource		*r;
1329 	int			status = 0, i;
1330 	u32			regs_offset = 0;
1331 	static int		bus_num = 1;
1332 	struct device_node	*node = pdev->dev.of_node;
1333 	const struct of_device_id *match;
1334 
1335 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1336 	if (master == NULL) {
1337 		dev_dbg(&pdev->dev, "master allocation failed\n");
1338 		return -ENOMEM;
1339 	}
1340 
1341 	/* the spi->mode bits understood by this driver: */
1342 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1343 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1344 	master->setup = omap2_mcspi_setup;
1345 	master->auto_runtime_pm = true;
1346 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
1347 	master->cleanup = omap2_mcspi_cleanup;
1348 	master->dev.of_node = node;
1349 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1350 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1351 
1352 	platform_set_drvdata(pdev, master);
1353 
1354 	mcspi = spi_master_get_devdata(master);
1355 	mcspi->master = master;
1356 
1357 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1358 	if (match) {
1359 		u32 num_cs = 1; /* default number of chipselect */
1360 		pdata = match->data;
1361 
1362 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1363 		master->num_chipselect = num_cs;
1364 		master->bus_num = bus_num++;
1365 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1366 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1367 	} else {
1368 		pdata = dev_get_platdata(&pdev->dev);
1369 		master->num_chipselect = pdata->num_cs;
1370 		if (pdev->id != -1)
1371 			master->bus_num = pdev->id;
1372 		mcspi->pin_dir = pdata->pin_dir;
1373 	}
1374 	regs_offset = pdata->regs_offset;
1375 
1376 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1377 	if (r == NULL) {
1378 		status = -ENODEV;
1379 		goto free_master;
1380 	}
1381 
1382 	r->start += regs_offset;
1383 	r->end += regs_offset;
1384 	mcspi->phys = r->start;
1385 
1386 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1387 	if (IS_ERR(mcspi->base)) {
1388 		status = PTR_ERR(mcspi->base);
1389 		goto free_master;
1390 	}
1391 
1392 	mcspi->dev = &pdev->dev;
1393 
1394 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1395 
1396 	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1397 					   sizeof(struct omap2_mcspi_dma),
1398 					   GFP_KERNEL);
1399 	if (mcspi->dma_channels == NULL) {
1400 		status = -ENOMEM;
1401 		goto free_master;
1402 	}
1403 
1404 	for (i = 0; i < master->num_chipselect; i++) {
1405 		char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1406 		char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1407 		struct resource *dma_res;
1408 
1409 		sprintf(dma_rx_ch_name, "rx%d", i);
1410 		if (!pdev->dev.of_node) {
1411 			dma_res =
1412 				platform_get_resource_byname(pdev,
1413 							     IORESOURCE_DMA,
1414 							     dma_rx_ch_name);
1415 			if (!dma_res) {
1416 				dev_dbg(&pdev->dev,
1417 					"cannot get DMA RX channel\n");
1418 				status = -ENODEV;
1419 				break;
1420 			}
1421 
1422 			mcspi->dma_channels[i].dma_rx_sync_dev =
1423 				dma_res->start;
1424 		}
1425 		sprintf(dma_tx_ch_name, "tx%d", i);
1426 		if (!pdev->dev.of_node) {
1427 			dma_res =
1428 				platform_get_resource_byname(pdev,
1429 							     IORESOURCE_DMA,
1430 							     dma_tx_ch_name);
1431 			if (!dma_res) {
1432 				dev_dbg(&pdev->dev,
1433 					"cannot get DMA TX channel\n");
1434 				status = -ENODEV;
1435 				break;
1436 			}
1437 
1438 			mcspi->dma_channels[i].dma_tx_sync_dev =
1439 				dma_res->start;
1440 		}
1441 	}
1442 
1443 	if (status < 0)
1444 		goto free_master;
1445 
1446 	pm_runtime_use_autosuspend(&pdev->dev);
1447 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1448 	pm_runtime_enable(&pdev->dev);
1449 
1450 	status = omap2_mcspi_master_setup(mcspi);
1451 	if (status < 0)
1452 		goto disable_pm;
1453 
1454 	status = devm_spi_register_master(&pdev->dev, master);
1455 	if (status < 0)
1456 		goto disable_pm;
1457 
1458 	return status;
1459 
1460 disable_pm:
1461 	pm_runtime_disable(&pdev->dev);
1462 free_master:
1463 	spi_master_put(master);
1464 	return status;
1465 }
1466 
1467 static int omap2_mcspi_remove(struct platform_device *pdev)
1468 {
1469 	struct spi_master *master = platform_get_drvdata(pdev);
1470 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1471 
1472 	pm_runtime_put_sync(mcspi->dev);
1473 	pm_runtime_disable(&pdev->dev);
1474 
1475 	return 0;
1476 }
1477 
1478 /* work with hotplug and coldplug */
1479 MODULE_ALIAS("platform:omap2_mcspi");
1480 
1481 #ifdef	CONFIG_SUSPEND
1482 /*
1483  * When SPI wake up from off-mode, CS is in activate state. If it was in
1484  * unactive state when driver was suspend, then force it to unactive state at
1485  * wake up.
1486  */
1487 static int omap2_mcspi_resume(struct device *dev)
1488 {
1489 	struct spi_master	*master = dev_get_drvdata(dev);
1490 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1491 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1492 	struct omap2_mcspi_cs	*cs;
1493 
1494 	pm_runtime_get_sync(mcspi->dev);
1495 	list_for_each_entry(cs, &ctx->cs, node) {
1496 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1497 			/*
1498 			 * We need to toggle CS state for OMAP take this
1499 			 * change in account.
1500 			 */
1501 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1502 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1503 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1504 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1505 		}
1506 	}
1507 	pm_runtime_mark_last_busy(mcspi->dev);
1508 	pm_runtime_put_autosuspend(mcspi->dev);
1509 	return 0;
1510 }
1511 #else
1512 #define	omap2_mcspi_resume	NULL
1513 #endif
1514 
1515 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1516 	.resume = omap2_mcspi_resume,
1517 	.runtime_resume	= omap_mcspi_runtime_resume,
1518 };
1519 
1520 static struct platform_driver omap2_mcspi_driver = {
1521 	.driver = {
1522 		.name =		"omap2_mcspi",
1523 		.owner =	THIS_MODULE,
1524 		.pm =		&omap2_mcspi_pm_ops,
1525 		.of_match_table = omap_mcspi_of_match,
1526 	},
1527 	.probe =	omap2_mcspi_probe,
1528 	.remove =	omap2_mcspi_remove,
1529 };
1530 
1531 module_platform_driver(omap2_mcspi_driver);
1532 MODULE_LICENSE("GPL");
1533