xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision 36bccb11)
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 	struct list_head	node;
153 	/* Context save and restore shadow register */
154 	u32			chconf0, chctrl0;
155 };
156 
157 static inline void mcspi_write_reg(struct spi_master *master,
158 		int idx, u32 val)
159 {
160 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
161 
162 	writel_relaxed(val, mcspi->base + idx);
163 }
164 
165 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
166 {
167 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
168 
169 	return readl_relaxed(mcspi->base + idx);
170 }
171 
172 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
173 		int idx, u32 val)
174 {
175 	struct omap2_mcspi_cs	*cs = spi->controller_state;
176 
177 	writel_relaxed(val, cs->base +  idx);
178 }
179 
180 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
181 {
182 	struct omap2_mcspi_cs	*cs = spi->controller_state;
183 
184 	return readl_relaxed(cs->base + idx);
185 }
186 
187 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
188 {
189 	struct omap2_mcspi_cs *cs = spi->controller_state;
190 
191 	return cs->chconf0;
192 }
193 
194 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
195 {
196 	struct omap2_mcspi_cs *cs = spi->controller_state;
197 
198 	cs->chconf0 = val;
199 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
200 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
201 }
202 
203 static inline int mcspi_bytes_per_word(int word_len)
204 {
205 	if (word_len <= 8)
206 		return 1;
207 	else if (word_len <= 16)
208 		return 2;
209 	else /* word_len <= 32 */
210 		return 4;
211 }
212 
213 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
214 		int is_read, int enable)
215 {
216 	u32 l, rw;
217 
218 	l = mcspi_cached_chconf0(spi);
219 
220 	if (is_read) /* 1 is read, 0 write */
221 		rw = OMAP2_MCSPI_CHCONF_DMAR;
222 	else
223 		rw = OMAP2_MCSPI_CHCONF_DMAW;
224 
225 	if (enable)
226 		l |= rw;
227 	else
228 		l &= ~rw;
229 
230 	mcspi_write_chconf0(spi, l);
231 }
232 
233 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
234 {
235 	struct omap2_mcspi_cs *cs = spi->controller_state;
236 	u32 l;
237 
238 	l = cs->chctrl0;
239 	if (enable)
240 		l |= OMAP2_MCSPI_CHCTRL_EN;
241 	else
242 		l &= ~OMAP2_MCSPI_CHCTRL_EN;
243 	cs->chctrl0 = l;
244 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
245 	/* Flash post-writes */
246 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
247 }
248 
249 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
250 {
251 	u32 l;
252 
253 	l = mcspi_cached_chconf0(spi);
254 	if (cs_active)
255 		l |= OMAP2_MCSPI_CHCONF_FORCE;
256 	else
257 		l &= ~OMAP2_MCSPI_CHCONF_FORCE;
258 
259 	mcspi_write_chconf0(spi, l);
260 }
261 
262 static void omap2_mcspi_set_master_mode(struct spi_master *master)
263 {
264 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
265 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
266 	u32 l;
267 
268 	/*
269 	 * Setup when switching from (reset default) slave mode
270 	 * to single-channel master mode
271 	 */
272 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
273 	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
274 	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
275 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
276 
277 	ctx->modulctrl = l;
278 }
279 
280 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
281 				struct spi_transfer *t, int enable)
282 {
283 	struct spi_master *master = spi->master;
284 	struct omap2_mcspi_cs *cs = spi->controller_state;
285 	struct omap2_mcspi *mcspi;
286 	unsigned int wcnt;
287 	int max_fifo_depth, fifo_depth, bytes_per_word;
288 	u32 chconf, xferlevel;
289 
290 	mcspi = spi_master_get_devdata(master);
291 
292 	chconf = mcspi_cached_chconf0(spi);
293 	if (enable) {
294 		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
295 		if (t->len % bytes_per_word != 0)
296 			goto disable_fifo;
297 
298 		if (t->rx_buf != NULL && t->tx_buf != NULL)
299 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
300 		else
301 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
302 
303 		fifo_depth = gcd(t->len, max_fifo_depth);
304 		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
305 			goto disable_fifo;
306 
307 		wcnt = t->len / bytes_per_word;
308 		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
309 			goto disable_fifo;
310 
311 		xferlevel = wcnt << 16;
312 		if (t->rx_buf != NULL) {
313 			chconf |= OMAP2_MCSPI_CHCONF_FFER;
314 			xferlevel |= (fifo_depth - 1) << 8;
315 		}
316 		if (t->tx_buf != NULL) {
317 			chconf |= OMAP2_MCSPI_CHCONF_FFET;
318 			xferlevel |= fifo_depth - 1;
319 		}
320 
321 		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
322 		mcspi_write_chconf0(spi, chconf);
323 		mcspi->fifo_depth = fifo_depth;
324 
325 		return;
326 	}
327 
328 disable_fifo:
329 	if (t->rx_buf != NULL)
330 		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
331 	else
332 		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
333 
334 	mcspi_write_chconf0(spi, chconf);
335 	mcspi->fifo_depth = 0;
336 }
337 
338 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
339 {
340 	struct spi_master	*spi_cntrl = mcspi->master;
341 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
342 	struct omap2_mcspi_cs	*cs;
343 
344 	/* McSPI: context restore */
345 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
346 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
347 
348 	list_for_each_entry(cs, &ctx->cs, node)
349 		writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
350 }
351 
352 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
353 {
354 	unsigned long timeout;
355 
356 	timeout = jiffies + msecs_to_jiffies(1000);
357 	while (!(readl_relaxed(reg) & bit)) {
358 		if (time_after(jiffies, timeout)) {
359 			if (!(readl_relaxed(reg) & bit))
360 				return -ETIMEDOUT;
361 			else
362 				return 0;
363 		}
364 		cpu_relax();
365 	}
366 	return 0;
367 }
368 
369 static void omap2_mcspi_rx_callback(void *data)
370 {
371 	struct spi_device *spi = data;
372 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
373 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
374 
375 	/* We must disable the DMA RX request */
376 	omap2_mcspi_set_dma_req(spi, 1, 0);
377 
378 	complete(&mcspi_dma->dma_rx_completion);
379 }
380 
381 static void omap2_mcspi_tx_callback(void *data)
382 {
383 	struct spi_device *spi = data;
384 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
385 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
386 
387 	/* We must disable the DMA TX request */
388 	omap2_mcspi_set_dma_req(spi, 0, 0);
389 
390 	complete(&mcspi_dma->dma_tx_completion);
391 }
392 
393 static void omap2_mcspi_tx_dma(struct spi_device *spi,
394 				struct spi_transfer *xfer,
395 				struct dma_slave_config cfg)
396 {
397 	struct omap2_mcspi	*mcspi;
398 	struct omap2_mcspi_dma  *mcspi_dma;
399 	unsigned int		count;
400 
401 	mcspi = spi_master_get_devdata(spi->master);
402 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
403 	count = xfer->len;
404 
405 	if (mcspi_dma->dma_tx) {
406 		struct dma_async_tx_descriptor *tx;
407 		struct scatterlist sg;
408 
409 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
410 
411 		sg_init_table(&sg, 1);
412 		sg_dma_address(&sg) = xfer->tx_dma;
413 		sg_dma_len(&sg) = xfer->len;
414 
415 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
416 		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
417 		if (tx) {
418 			tx->callback = omap2_mcspi_tx_callback;
419 			tx->callback_param = spi;
420 			dmaengine_submit(tx);
421 		} else {
422 			/* FIXME: fall back to PIO? */
423 		}
424 	}
425 	dma_async_issue_pending(mcspi_dma->dma_tx);
426 	omap2_mcspi_set_dma_req(spi, 0, 1);
427 
428 }
429 
430 static unsigned
431 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
432 				struct dma_slave_config cfg,
433 				unsigned es)
434 {
435 	struct omap2_mcspi	*mcspi;
436 	struct omap2_mcspi_dma  *mcspi_dma;
437 	unsigned int		count, dma_count;
438 	u32			l;
439 	int			elements = 0;
440 	int			word_len, element_count;
441 	struct omap2_mcspi_cs	*cs = spi->controller_state;
442 	mcspi = spi_master_get_devdata(spi->master);
443 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
444 	count = xfer->len;
445 	dma_count = xfer->len;
446 
447 	if (mcspi->fifo_depth == 0)
448 		dma_count -= es;
449 
450 	word_len = cs->word_len;
451 	l = mcspi_cached_chconf0(spi);
452 
453 	if (word_len <= 8)
454 		element_count = count;
455 	else if (word_len <= 16)
456 		element_count = count >> 1;
457 	else /* word_len <= 32 */
458 		element_count = count >> 2;
459 
460 	if (mcspi_dma->dma_rx) {
461 		struct dma_async_tx_descriptor *tx;
462 		struct scatterlist sg;
463 
464 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
465 
466 		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
467 			dma_count -= es;
468 
469 		sg_init_table(&sg, 1);
470 		sg_dma_address(&sg) = xfer->rx_dma;
471 		sg_dma_len(&sg) = dma_count;
472 
473 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
474 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
475 				DMA_CTRL_ACK);
476 		if (tx) {
477 			tx->callback = omap2_mcspi_rx_callback;
478 			tx->callback_param = spi;
479 			dmaengine_submit(tx);
480 		} else {
481 				/* FIXME: fall back to PIO? */
482 		}
483 	}
484 
485 	dma_async_issue_pending(mcspi_dma->dma_rx);
486 	omap2_mcspi_set_dma_req(spi, 1, 1);
487 
488 	wait_for_completion(&mcspi_dma->dma_rx_completion);
489 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
490 			 DMA_FROM_DEVICE);
491 
492 	if (mcspi->fifo_depth > 0)
493 		return count;
494 
495 	omap2_mcspi_set_enable(spi, 0);
496 
497 	elements = element_count - 1;
498 
499 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
500 		elements--;
501 
502 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
503 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
504 			u32 w;
505 
506 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
507 			if (word_len <= 8)
508 				((u8 *)xfer->rx_buf)[elements++] = w;
509 			else if (word_len <= 16)
510 				((u16 *)xfer->rx_buf)[elements++] = w;
511 			else /* word_len <= 32 */
512 				((u32 *)xfer->rx_buf)[elements++] = w;
513 		} else {
514 			int bytes_per_word = mcspi_bytes_per_word(word_len);
515 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
516 			count -= (bytes_per_word << 1);
517 			omap2_mcspi_set_enable(spi, 1);
518 			return count;
519 		}
520 	}
521 	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
522 				& OMAP2_MCSPI_CHSTAT_RXS)) {
523 		u32 w;
524 
525 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
526 		if (word_len <= 8)
527 			((u8 *)xfer->rx_buf)[elements] = w;
528 		else if (word_len <= 16)
529 			((u16 *)xfer->rx_buf)[elements] = w;
530 		else /* word_len <= 32 */
531 			((u32 *)xfer->rx_buf)[elements] = w;
532 	} else {
533 		dev_err(&spi->dev, "DMA RX last word empty\n");
534 		count -= mcspi_bytes_per_word(word_len);
535 	}
536 	omap2_mcspi_set_enable(spi, 1);
537 	return count;
538 }
539 
540 static unsigned
541 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
542 {
543 	struct omap2_mcspi	*mcspi;
544 	struct omap2_mcspi_cs	*cs = spi->controller_state;
545 	struct omap2_mcspi_dma  *mcspi_dma;
546 	unsigned int		count;
547 	u32			l;
548 	u8			*rx;
549 	const u8		*tx;
550 	struct dma_slave_config	cfg;
551 	enum dma_slave_buswidth width;
552 	unsigned es;
553 	u32			burst;
554 	void __iomem		*chstat_reg;
555 	void __iomem            *irqstat_reg;
556 	int			wait_res;
557 
558 	mcspi = spi_master_get_devdata(spi->master);
559 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
560 	l = mcspi_cached_chconf0(spi);
561 
562 
563 	if (cs->word_len <= 8) {
564 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
565 		es = 1;
566 	} else if (cs->word_len <= 16) {
567 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
568 		es = 2;
569 	} else {
570 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
571 		es = 4;
572 	}
573 
574 	count = xfer->len;
575 	burst = 1;
576 
577 	if (mcspi->fifo_depth > 0) {
578 		if (count > mcspi->fifo_depth)
579 			burst = mcspi->fifo_depth / es;
580 		else
581 			burst = count / es;
582 	}
583 
584 	memset(&cfg, 0, sizeof(cfg));
585 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
586 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
587 	cfg.src_addr_width = width;
588 	cfg.dst_addr_width = width;
589 	cfg.src_maxburst = burst;
590 	cfg.dst_maxburst = burst;
591 
592 	rx = xfer->rx_buf;
593 	tx = xfer->tx_buf;
594 
595 	if (tx != NULL)
596 		omap2_mcspi_tx_dma(spi, xfer, cfg);
597 
598 	if (rx != NULL)
599 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
600 
601 	if (tx != NULL) {
602 		wait_for_completion(&mcspi_dma->dma_tx_completion);
603 		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
604 				 DMA_TO_DEVICE);
605 
606 		if (mcspi->fifo_depth > 0) {
607 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
608 
609 			if (mcspi_wait_for_reg_bit(irqstat_reg,
610 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
611 				dev_err(&spi->dev, "EOW timed out\n");
612 
613 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
614 					OMAP2_MCSPI_IRQSTATUS_EOW);
615 		}
616 
617 		/* for TX_ONLY mode, be sure all words have shifted out */
618 		if (rx == NULL) {
619 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
620 			if (mcspi->fifo_depth > 0) {
621 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
622 						OMAP2_MCSPI_CHSTAT_TXFFE);
623 				if (wait_res < 0)
624 					dev_err(&spi->dev, "TXFFE timed out\n");
625 			} else {
626 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
627 						OMAP2_MCSPI_CHSTAT_TXS);
628 				if (wait_res < 0)
629 					dev_err(&spi->dev, "TXS timed out\n");
630 			}
631 			if (wait_res >= 0 &&
632 				(mcspi_wait_for_reg_bit(chstat_reg,
633 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
634 				dev_err(&spi->dev, "EOT timed out\n");
635 		}
636 	}
637 	return count;
638 }
639 
640 static unsigned
641 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
642 {
643 	struct omap2_mcspi	*mcspi;
644 	struct omap2_mcspi_cs	*cs = spi->controller_state;
645 	unsigned int		count, c;
646 	u32			l;
647 	void __iomem		*base = cs->base;
648 	void __iomem		*tx_reg;
649 	void __iomem		*rx_reg;
650 	void __iomem		*chstat_reg;
651 	int			word_len;
652 
653 	mcspi = spi_master_get_devdata(spi->master);
654 	count = xfer->len;
655 	c = count;
656 	word_len = cs->word_len;
657 
658 	l = mcspi_cached_chconf0(spi);
659 
660 	/* We store the pre-calculated register addresses on stack to speed
661 	 * up the transfer loop. */
662 	tx_reg		= base + OMAP2_MCSPI_TX0;
663 	rx_reg		= base + OMAP2_MCSPI_RX0;
664 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
665 
666 	if (c < (word_len>>3))
667 		return 0;
668 
669 	if (word_len <= 8) {
670 		u8		*rx;
671 		const u8	*tx;
672 
673 		rx = xfer->rx_buf;
674 		tx = xfer->tx_buf;
675 
676 		do {
677 			c -= 1;
678 			if (tx != NULL) {
679 				if (mcspi_wait_for_reg_bit(chstat_reg,
680 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
681 					dev_err(&spi->dev, "TXS timed out\n");
682 					goto out;
683 				}
684 				dev_vdbg(&spi->dev, "write-%d %02x\n",
685 						word_len, *tx);
686 				writel_relaxed(*tx++, tx_reg);
687 			}
688 			if (rx != NULL) {
689 				if (mcspi_wait_for_reg_bit(chstat_reg,
690 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
691 					dev_err(&spi->dev, "RXS timed out\n");
692 					goto out;
693 				}
694 
695 				if (c == 1 && tx == NULL &&
696 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
697 					omap2_mcspi_set_enable(spi, 0);
698 					*rx++ = readl_relaxed(rx_reg);
699 					dev_vdbg(&spi->dev, "read-%d %02x\n",
700 						    word_len, *(rx - 1));
701 					if (mcspi_wait_for_reg_bit(chstat_reg,
702 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
703 						dev_err(&spi->dev,
704 							"RXS timed out\n");
705 						goto out;
706 					}
707 					c = 0;
708 				} else if (c == 0 && tx == NULL) {
709 					omap2_mcspi_set_enable(spi, 0);
710 				}
711 
712 				*rx++ = readl_relaxed(rx_reg);
713 				dev_vdbg(&spi->dev, "read-%d %02x\n",
714 						word_len, *(rx - 1));
715 			}
716 		} while (c);
717 	} else if (word_len <= 16) {
718 		u16		*rx;
719 		const u16	*tx;
720 
721 		rx = xfer->rx_buf;
722 		tx = xfer->tx_buf;
723 		do {
724 			c -= 2;
725 			if (tx != NULL) {
726 				if (mcspi_wait_for_reg_bit(chstat_reg,
727 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
728 					dev_err(&spi->dev, "TXS timed out\n");
729 					goto out;
730 				}
731 				dev_vdbg(&spi->dev, "write-%d %04x\n",
732 						word_len, *tx);
733 				writel_relaxed(*tx++, tx_reg);
734 			}
735 			if (rx != NULL) {
736 				if (mcspi_wait_for_reg_bit(chstat_reg,
737 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
738 					dev_err(&spi->dev, "RXS timed out\n");
739 					goto out;
740 				}
741 
742 				if (c == 2 && tx == NULL &&
743 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
744 					omap2_mcspi_set_enable(spi, 0);
745 					*rx++ = readl_relaxed(rx_reg);
746 					dev_vdbg(&spi->dev, "read-%d %04x\n",
747 						    word_len, *(rx - 1));
748 					if (mcspi_wait_for_reg_bit(chstat_reg,
749 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
750 						dev_err(&spi->dev,
751 							"RXS timed out\n");
752 						goto out;
753 					}
754 					c = 0;
755 				} else if (c == 0 && tx == NULL) {
756 					omap2_mcspi_set_enable(spi, 0);
757 				}
758 
759 				*rx++ = readl_relaxed(rx_reg);
760 				dev_vdbg(&spi->dev, "read-%d %04x\n",
761 						word_len, *(rx - 1));
762 			}
763 		} while (c >= 2);
764 	} else if (word_len <= 32) {
765 		u32		*rx;
766 		const u32	*tx;
767 
768 		rx = xfer->rx_buf;
769 		tx = xfer->tx_buf;
770 		do {
771 			c -= 4;
772 			if (tx != NULL) {
773 				if (mcspi_wait_for_reg_bit(chstat_reg,
774 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
775 					dev_err(&spi->dev, "TXS timed out\n");
776 					goto out;
777 				}
778 				dev_vdbg(&spi->dev, "write-%d %08x\n",
779 						word_len, *tx);
780 				writel_relaxed(*tx++, tx_reg);
781 			}
782 			if (rx != NULL) {
783 				if (mcspi_wait_for_reg_bit(chstat_reg,
784 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
785 					dev_err(&spi->dev, "RXS timed out\n");
786 					goto out;
787 				}
788 
789 				if (c == 4 && tx == NULL &&
790 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
791 					omap2_mcspi_set_enable(spi, 0);
792 					*rx++ = readl_relaxed(rx_reg);
793 					dev_vdbg(&spi->dev, "read-%d %08x\n",
794 						    word_len, *(rx - 1));
795 					if (mcspi_wait_for_reg_bit(chstat_reg,
796 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
797 						dev_err(&spi->dev,
798 							"RXS timed out\n");
799 						goto out;
800 					}
801 					c = 0;
802 				} else if (c == 0 && tx == NULL) {
803 					omap2_mcspi_set_enable(spi, 0);
804 				}
805 
806 				*rx++ = readl_relaxed(rx_reg);
807 				dev_vdbg(&spi->dev, "read-%d %08x\n",
808 						word_len, *(rx - 1));
809 			}
810 		} while (c >= 4);
811 	}
812 
813 	/* for TX_ONLY mode, be sure all words have shifted out */
814 	if (xfer->rx_buf == NULL) {
815 		if (mcspi_wait_for_reg_bit(chstat_reg,
816 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
817 			dev_err(&spi->dev, "TXS timed out\n");
818 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
819 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
820 			dev_err(&spi->dev, "EOT timed out\n");
821 
822 		/* disable chan to purge rx datas received in TX_ONLY transfer,
823 		 * otherwise these rx datas will affect the direct following
824 		 * RX_ONLY transfer.
825 		 */
826 		omap2_mcspi_set_enable(spi, 0);
827 	}
828 out:
829 	omap2_mcspi_set_enable(spi, 1);
830 	return count - c;
831 }
832 
833 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
834 {
835 	u32 div;
836 
837 	for (div = 0; div < 15; div++)
838 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
839 			return div;
840 
841 	return 15;
842 }
843 
844 /* called only when no transfer is active to this device */
845 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
846 		struct spi_transfer *t)
847 {
848 	struct omap2_mcspi_cs *cs = spi->controller_state;
849 	struct omap2_mcspi *mcspi;
850 	struct spi_master *spi_cntrl;
851 	u32 l = 0, clkd = 0, div, extclk = 0, clkg = 0;
852 	u8 word_len = spi->bits_per_word;
853 	u32 speed_hz = spi->max_speed_hz;
854 
855 	mcspi = spi_master_get_devdata(spi->master);
856 	spi_cntrl = mcspi->master;
857 
858 	if (t != NULL && t->bits_per_word)
859 		word_len = t->bits_per_word;
860 
861 	cs->word_len = word_len;
862 
863 	if (t && t->speed_hz)
864 		speed_hz = t->speed_hz;
865 
866 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
867 	if (speed_hz < (OMAP2_MCSPI_MAX_FREQ / OMAP2_MCSPI_MAX_DIVIDER)) {
868 		clkd = omap2_mcspi_calc_divisor(speed_hz);
869 		speed_hz = OMAP2_MCSPI_MAX_FREQ >> clkd;
870 		clkg = 0;
871 	} else {
872 		div = (OMAP2_MCSPI_MAX_FREQ + speed_hz - 1) / speed_hz;
873 		speed_hz = OMAP2_MCSPI_MAX_FREQ / div;
874 		clkd = (div - 1) & 0xf;
875 		extclk = (div - 1) >> 4;
876 		clkg = OMAP2_MCSPI_CHCONF_CLKG;
877 	}
878 
879 	l = mcspi_cached_chconf0(spi);
880 
881 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
882 	 * REVISIT: this controller could support SPI_3WIRE mode.
883 	 */
884 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
885 		l &= ~OMAP2_MCSPI_CHCONF_IS;
886 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
887 		l |= OMAP2_MCSPI_CHCONF_DPE0;
888 	} else {
889 		l |= OMAP2_MCSPI_CHCONF_IS;
890 		l |= OMAP2_MCSPI_CHCONF_DPE1;
891 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
892 	}
893 
894 	/* wordlength */
895 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
896 	l |= (word_len - 1) << 7;
897 
898 	/* set chipselect polarity; manage with FORCE */
899 	if (!(spi->mode & SPI_CS_HIGH))
900 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
901 	else
902 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
903 
904 	/* set clock divisor */
905 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
906 	l |= clkd << 2;
907 
908 	/* set clock granularity */
909 	l &= ~OMAP2_MCSPI_CHCONF_CLKG;
910 	l |= clkg;
911 	if (clkg) {
912 		cs->chctrl0 &= ~OMAP2_MCSPI_CHCTRL_EXTCLK_MASK;
913 		cs->chctrl0 |= extclk << 8;
914 		mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, cs->chctrl0);
915 	}
916 
917 	/* set SPI mode 0..3 */
918 	if (spi->mode & SPI_CPOL)
919 		l |= OMAP2_MCSPI_CHCONF_POL;
920 	else
921 		l &= ~OMAP2_MCSPI_CHCONF_POL;
922 	if (spi->mode & SPI_CPHA)
923 		l |= OMAP2_MCSPI_CHCONF_PHA;
924 	else
925 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
926 
927 	mcspi_write_chconf0(spi, l);
928 
929 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
930 			speed_hz,
931 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
932 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
933 
934 	return 0;
935 }
936 
937 /*
938  * Note that we currently allow DMA only if we get a channel
939  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
940  */
941 static int omap2_mcspi_request_dma(struct spi_device *spi)
942 {
943 	struct spi_master	*master = spi->master;
944 	struct omap2_mcspi	*mcspi;
945 	struct omap2_mcspi_dma	*mcspi_dma;
946 	dma_cap_mask_t mask;
947 	unsigned sig;
948 
949 	mcspi = spi_master_get_devdata(master);
950 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
951 
952 	init_completion(&mcspi_dma->dma_rx_completion);
953 	init_completion(&mcspi_dma->dma_tx_completion);
954 
955 	dma_cap_zero(mask);
956 	dma_cap_set(DMA_SLAVE, mask);
957 	sig = mcspi_dma->dma_rx_sync_dev;
958 
959 	mcspi_dma->dma_rx =
960 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
961 						 &sig, &master->dev,
962 						 mcspi_dma->dma_rx_ch_name);
963 	if (!mcspi_dma->dma_rx)
964 		goto no_dma;
965 
966 	sig = mcspi_dma->dma_tx_sync_dev;
967 	mcspi_dma->dma_tx =
968 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
969 						 &sig, &master->dev,
970 						 mcspi_dma->dma_tx_ch_name);
971 
972 	if (!mcspi_dma->dma_tx) {
973 		dma_release_channel(mcspi_dma->dma_rx);
974 		mcspi_dma->dma_rx = NULL;
975 		goto no_dma;
976 	}
977 
978 	return 0;
979 
980 no_dma:
981 	dev_warn(&spi->dev, "not using DMA for McSPI\n");
982 	return -EAGAIN;
983 }
984 
985 static int omap2_mcspi_setup(struct spi_device *spi)
986 {
987 	int			ret;
988 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
989 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
990 	struct omap2_mcspi_dma	*mcspi_dma;
991 	struct omap2_mcspi_cs	*cs = spi->controller_state;
992 
993 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
994 
995 	if (!cs) {
996 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
997 		if (!cs)
998 			return -ENOMEM;
999 		cs->base = mcspi->base + spi->chip_select * 0x14;
1000 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
1001 		cs->chconf0 = 0;
1002 		cs->chctrl0 = 0;
1003 		spi->controller_state = cs;
1004 		/* Link this to context save list */
1005 		list_add_tail(&cs->node, &ctx->cs);
1006 	}
1007 
1008 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
1009 		ret = omap2_mcspi_request_dma(spi);
1010 		if (ret < 0 && ret != -EAGAIN)
1011 			return ret;
1012 	}
1013 
1014 	ret = pm_runtime_get_sync(mcspi->dev);
1015 	if (ret < 0)
1016 		return ret;
1017 
1018 	ret = omap2_mcspi_setup_transfer(spi, NULL);
1019 	pm_runtime_mark_last_busy(mcspi->dev);
1020 	pm_runtime_put_autosuspend(mcspi->dev);
1021 
1022 	return ret;
1023 }
1024 
1025 static void omap2_mcspi_cleanup(struct spi_device *spi)
1026 {
1027 	struct omap2_mcspi	*mcspi;
1028 	struct omap2_mcspi_dma	*mcspi_dma;
1029 	struct omap2_mcspi_cs	*cs;
1030 
1031 	mcspi = spi_master_get_devdata(spi->master);
1032 
1033 	if (spi->controller_state) {
1034 		/* Unlink controller state from context save list */
1035 		cs = spi->controller_state;
1036 		list_del(&cs->node);
1037 
1038 		kfree(cs);
1039 	}
1040 
1041 	if (spi->chip_select < spi->master->num_chipselect) {
1042 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1043 
1044 		if (mcspi_dma->dma_rx) {
1045 			dma_release_channel(mcspi_dma->dma_rx);
1046 			mcspi_dma->dma_rx = NULL;
1047 		}
1048 		if (mcspi_dma->dma_tx) {
1049 			dma_release_channel(mcspi_dma->dma_tx);
1050 			mcspi_dma->dma_tx = NULL;
1051 		}
1052 	}
1053 }
1054 
1055 static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
1056 {
1057 
1058 	/* We only enable one channel at a time -- the one whose message is
1059 	 * -- although this controller would gladly
1060 	 * arbitrate among multiple channels.  This corresponds to "single
1061 	 * channel" master mode.  As a side effect, we need to manage the
1062 	 * chipselect with the FORCE bit ... CS != channel enable.
1063 	 */
1064 
1065 	struct spi_device		*spi;
1066 	struct spi_transfer		*t = NULL;
1067 	struct spi_master		*master;
1068 	struct omap2_mcspi_dma		*mcspi_dma;
1069 	int				cs_active = 0;
1070 	struct omap2_mcspi_cs		*cs;
1071 	struct omap2_mcspi_device_config *cd;
1072 	int				par_override = 0;
1073 	int				status = 0;
1074 	u32				chconf;
1075 
1076 	spi = m->spi;
1077 	master = spi->master;
1078 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1079 	cs = spi->controller_state;
1080 	cd = spi->controller_data;
1081 
1082 	omap2_mcspi_set_enable(spi, 0);
1083 	list_for_each_entry(t, &m->transfers, transfer_list) {
1084 		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
1085 			status = -EINVAL;
1086 			break;
1087 		}
1088 		if (par_override ||
1089 		    (t->speed_hz != spi->max_speed_hz) ||
1090 		    (t->bits_per_word != spi->bits_per_word)) {
1091 			par_override = 1;
1092 			status = omap2_mcspi_setup_transfer(spi, t);
1093 			if (status < 0)
1094 				break;
1095 			if (t->speed_hz == spi->max_speed_hz &&
1096 			    t->bits_per_word == spi->bits_per_word)
1097 				par_override = 0;
1098 		}
1099 		if (cd && cd->cs_per_word) {
1100 			chconf = mcspi->ctx.modulctrl;
1101 			chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1102 			mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1103 			mcspi->ctx.modulctrl =
1104 				mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1105 		}
1106 
1107 
1108 		if (!cs_active) {
1109 			omap2_mcspi_force_cs(spi, 1);
1110 			cs_active = 1;
1111 		}
1112 
1113 		chconf = mcspi_cached_chconf0(spi);
1114 		chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1115 		chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1116 
1117 		if (t->tx_buf == NULL)
1118 			chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1119 		else if (t->rx_buf == NULL)
1120 			chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1121 
1122 		if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1123 			/* Turbo mode is for more than one word */
1124 			if (t->len > ((cs->word_len + 7) >> 3))
1125 				chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1126 		}
1127 
1128 		mcspi_write_chconf0(spi, chconf);
1129 
1130 		if (t->len) {
1131 			unsigned	count;
1132 
1133 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1134 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1135 				omap2_mcspi_set_fifo(spi, t, 1);
1136 
1137 			omap2_mcspi_set_enable(spi, 1);
1138 
1139 			/* RX_ONLY mode needs dummy data in TX reg */
1140 			if (t->tx_buf == NULL)
1141 				writel_relaxed(0, cs->base
1142 						+ OMAP2_MCSPI_TX0);
1143 
1144 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1145 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1146 				count = omap2_mcspi_txrx_dma(spi, t);
1147 			else
1148 				count = omap2_mcspi_txrx_pio(spi, t);
1149 			m->actual_length += count;
1150 
1151 			if (count != t->len) {
1152 				status = -EIO;
1153 				break;
1154 			}
1155 		}
1156 
1157 		if (t->delay_usecs)
1158 			udelay(t->delay_usecs);
1159 
1160 		/* ignore the "leave it on after last xfer" hint */
1161 		if (t->cs_change) {
1162 			omap2_mcspi_force_cs(spi, 0);
1163 			cs_active = 0;
1164 		}
1165 
1166 		omap2_mcspi_set_enable(spi, 0);
1167 
1168 		if (mcspi->fifo_depth > 0)
1169 			omap2_mcspi_set_fifo(spi, t, 0);
1170 	}
1171 	/* Restore defaults if they were overriden */
1172 	if (par_override) {
1173 		par_override = 0;
1174 		status = omap2_mcspi_setup_transfer(spi, NULL);
1175 	}
1176 
1177 	if (cs_active)
1178 		omap2_mcspi_force_cs(spi, 0);
1179 
1180 	if (cd && cd->cs_per_word) {
1181 		chconf = mcspi->ctx.modulctrl;
1182 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1183 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1184 		mcspi->ctx.modulctrl =
1185 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1186 	}
1187 
1188 	omap2_mcspi_set_enable(spi, 0);
1189 
1190 	if (mcspi->fifo_depth > 0 && t)
1191 		omap2_mcspi_set_fifo(spi, t, 0);
1192 
1193 	m->status = status;
1194 }
1195 
1196 static int omap2_mcspi_transfer_one_message(struct spi_master *master,
1197 		struct spi_message *m)
1198 {
1199 	struct spi_device	*spi;
1200 	struct omap2_mcspi	*mcspi;
1201 	struct omap2_mcspi_dma	*mcspi_dma;
1202 	struct spi_transfer	*t;
1203 
1204 	spi = m->spi;
1205 	mcspi = spi_master_get_devdata(master);
1206 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1207 	m->actual_length = 0;
1208 	m->status = 0;
1209 
1210 	list_for_each_entry(t, &m->transfers, transfer_list) {
1211 		const void	*tx_buf = t->tx_buf;
1212 		void		*rx_buf = t->rx_buf;
1213 		unsigned	len = t->len;
1214 
1215 		if ((len && !(rx_buf || tx_buf))) {
1216 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1217 					t->speed_hz,
1218 					len,
1219 					tx_buf ? "tx" : "",
1220 					rx_buf ? "rx" : "",
1221 					t->bits_per_word);
1222 			return -EINVAL;
1223 		}
1224 
1225 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1226 			continue;
1227 
1228 		if (mcspi_dma->dma_tx && tx_buf != NULL) {
1229 			t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1230 					len, DMA_TO_DEVICE);
1231 			if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1232 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1233 						'T', len);
1234 				return -EINVAL;
1235 			}
1236 		}
1237 		if (mcspi_dma->dma_rx && rx_buf != NULL) {
1238 			t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1239 					DMA_FROM_DEVICE);
1240 			if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1241 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1242 						'R', len);
1243 				if (tx_buf != NULL)
1244 					dma_unmap_single(mcspi->dev, t->tx_dma,
1245 							len, DMA_TO_DEVICE);
1246 				return -EINVAL;
1247 			}
1248 		}
1249 	}
1250 
1251 	omap2_mcspi_work(mcspi, m);
1252 	spi_finalize_current_message(master);
1253 	return 0;
1254 }
1255 
1256 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1257 {
1258 	struct spi_master	*master = mcspi->master;
1259 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1260 	int			ret = 0;
1261 
1262 	ret = pm_runtime_get_sync(mcspi->dev);
1263 	if (ret < 0)
1264 		return ret;
1265 
1266 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1267 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1268 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1269 
1270 	omap2_mcspi_set_master_mode(master);
1271 	pm_runtime_mark_last_busy(mcspi->dev);
1272 	pm_runtime_put_autosuspend(mcspi->dev);
1273 	return 0;
1274 }
1275 
1276 static int omap_mcspi_runtime_resume(struct device *dev)
1277 {
1278 	struct omap2_mcspi	*mcspi;
1279 	struct spi_master	*master;
1280 
1281 	master = dev_get_drvdata(dev);
1282 	mcspi = spi_master_get_devdata(master);
1283 	omap2_mcspi_restore_ctx(mcspi);
1284 
1285 	return 0;
1286 }
1287 
1288 static struct omap2_mcspi_platform_config omap2_pdata = {
1289 	.regs_offset = 0,
1290 };
1291 
1292 static struct omap2_mcspi_platform_config omap4_pdata = {
1293 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1294 };
1295 
1296 static const struct of_device_id omap_mcspi_of_match[] = {
1297 	{
1298 		.compatible = "ti,omap2-mcspi",
1299 		.data = &omap2_pdata,
1300 	},
1301 	{
1302 		.compatible = "ti,omap4-mcspi",
1303 		.data = &omap4_pdata,
1304 	},
1305 	{ },
1306 };
1307 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1308 
1309 static int omap2_mcspi_probe(struct platform_device *pdev)
1310 {
1311 	struct spi_master	*master;
1312 	const struct omap2_mcspi_platform_config *pdata;
1313 	struct omap2_mcspi	*mcspi;
1314 	struct resource		*r;
1315 	int			status = 0, i;
1316 	u32			regs_offset = 0;
1317 	static int		bus_num = 1;
1318 	struct device_node	*node = pdev->dev.of_node;
1319 	const struct of_device_id *match;
1320 
1321 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1322 	if (master == NULL) {
1323 		dev_dbg(&pdev->dev, "master allocation failed\n");
1324 		return -ENOMEM;
1325 	}
1326 
1327 	/* the spi->mode bits understood by this driver: */
1328 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1329 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1330 	master->setup = omap2_mcspi_setup;
1331 	master->auto_runtime_pm = true;
1332 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
1333 	master->cleanup = omap2_mcspi_cleanup;
1334 	master->dev.of_node = node;
1335 	master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
1336 	master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
1337 
1338 	platform_set_drvdata(pdev, master);
1339 
1340 	mcspi = spi_master_get_devdata(master);
1341 	mcspi->master = master;
1342 
1343 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1344 	if (match) {
1345 		u32 num_cs = 1; /* default number of chipselect */
1346 		pdata = match->data;
1347 
1348 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1349 		master->num_chipselect = num_cs;
1350 		master->bus_num = bus_num++;
1351 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1352 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1353 	} else {
1354 		pdata = dev_get_platdata(&pdev->dev);
1355 		master->num_chipselect = pdata->num_cs;
1356 		if (pdev->id != -1)
1357 			master->bus_num = pdev->id;
1358 		mcspi->pin_dir = pdata->pin_dir;
1359 	}
1360 	regs_offset = pdata->regs_offset;
1361 
1362 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1363 	if (r == NULL) {
1364 		status = -ENODEV;
1365 		goto free_master;
1366 	}
1367 
1368 	r->start += regs_offset;
1369 	r->end += regs_offset;
1370 	mcspi->phys = r->start;
1371 
1372 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1373 	if (IS_ERR(mcspi->base)) {
1374 		status = PTR_ERR(mcspi->base);
1375 		goto free_master;
1376 	}
1377 
1378 	mcspi->dev = &pdev->dev;
1379 
1380 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1381 
1382 	mcspi->dma_channels = devm_kcalloc(&pdev->dev, master->num_chipselect,
1383 					   sizeof(struct omap2_mcspi_dma),
1384 					   GFP_KERNEL);
1385 	if (mcspi->dma_channels == NULL) {
1386 		status = -ENOMEM;
1387 		goto free_master;
1388 	}
1389 
1390 	for (i = 0; i < master->num_chipselect; i++) {
1391 		char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1392 		char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1393 		struct resource *dma_res;
1394 
1395 		sprintf(dma_rx_ch_name, "rx%d", i);
1396 		if (!pdev->dev.of_node) {
1397 			dma_res =
1398 				platform_get_resource_byname(pdev,
1399 							     IORESOURCE_DMA,
1400 							     dma_rx_ch_name);
1401 			if (!dma_res) {
1402 				dev_dbg(&pdev->dev,
1403 					"cannot get DMA RX channel\n");
1404 				status = -ENODEV;
1405 				break;
1406 			}
1407 
1408 			mcspi->dma_channels[i].dma_rx_sync_dev =
1409 				dma_res->start;
1410 		}
1411 		sprintf(dma_tx_ch_name, "tx%d", i);
1412 		if (!pdev->dev.of_node) {
1413 			dma_res =
1414 				platform_get_resource_byname(pdev,
1415 							     IORESOURCE_DMA,
1416 							     dma_tx_ch_name);
1417 			if (!dma_res) {
1418 				dev_dbg(&pdev->dev,
1419 					"cannot get DMA TX channel\n");
1420 				status = -ENODEV;
1421 				break;
1422 			}
1423 
1424 			mcspi->dma_channels[i].dma_tx_sync_dev =
1425 				dma_res->start;
1426 		}
1427 	}
1428 
1429 	if (status < 0)
1430 		goto free_master;
1431 
1432 	pm_runtime_use_autosuspend(&pdev->dev);
1433 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1434 	pm_runtime_enable(&pdev->dev);
1435 
1436 	status = omap2_mcspi_master_setup(mcspi);
1437 	if (status < 0)
1438 		goto disable_pm;
1439 
1440 	status = devm_spi_register_master(&pdev->dev, master);
1441 	if (status < 0)
1442 		goto disable_pm;
1443 
1444 	return status;
1445 
1446 disable_pm:
1447 	pm_runtime_disable(&pdev->dev);
1448 free_master:
1449 	spi_master_put(master);
1450 	return status;
1451 }
1452 
1453 static int omap2_mcspi_remove(struct platform_device *pdev)
1454 {
1455 	struct spi_master *master = platform_get_drvdata(pdev);
1456 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
1457 
1458 	pm_runtime_put_sync(mcspi->dev);
1459 	pm_runtime_disable(&pdev->dev);
1460 
1461 	return 0;
1462 }
1463 
1464 /* work with hotplug and coldplug */
1465 MODULE_ALIAS("platform:omap2_mcspi");
1466 
1467 #ifdef	CONFIG_SUSPEND
1468 /*
1469  * When SPI wake up from off-mode, CS is in activate state. If it was in
1470  * unactive state when driver was suspend, then force it to unactive state at
1471  * wake up.
1472  */
1473 static int omap2_mcspi_resume(struct device *dev)
1474 {
1475 	struct spi_master	*master = dev_get_drvdata(dev);
1476 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1477 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1478 	struct omap2_mcspi_cs	*cs;
1479 
1480 	pm_runtime_get_sync(mcspi->dev);
1481 	list_for_each_entry(cs, &ctx->cs, node) {
1482 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1483 			/*
1484 			 * We need to toggle CS state for OMAP take this
1485 			 * change in account.
1486 			 */
1487 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1488 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1489 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1490 			writel_relaxed(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1491 		}
1492 	}
1493 	pm_runtime_mark_last_busy(mcspi->dev);
1494 	pm_runtime_put_autosuspend(mcspi->dev);
1495 	return 0;
1496 }
1497 #else
1498 #define	omap2_mcspi_resume	NULL
1499 #endif
1500 
1501 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1502 	.resume = omap2_mcspi_resume,
1503 	.runtime_resume	= omap_mcspi_runtime_resume,
1504 };
1505 
1506 static struct platform_driver omap2_mcspi_driver = {
1507 	.driver = {
1508 		.name =		"omap2_mcspi",
1509 		.owner =	THIS_MODULE,
1510 		.pm =		&omap2_mcspi_pm_ops,
1511 		.of_match_table = omap_mcspi_of_match,
1512 	},
1513 	.probe =	omap2_mcspi_probe,
1514 	.remove =	omap2_mcspi_remove,
1515 };
1516 
1517 module_platform_driver(omap2_mcspi_driver);
1518 MODULE_LICENSE("GPL");
1519