xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision 31b90347)
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/init.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/device.h>
29 #include <linux/delay.h>
30 #include <linux/dma-mapping.h>
31 #include <linux/dmaengine.h>
32 #include <linux/omap-dma.h>
33 #include <linux/platform_device.h>
34 #include <linux/err.h>
35 #include <linux/clk.h>
36 #include <linux/io.h>
37 #include <linux/slab.h>
38 #include <linux/pm_runtime.h>
39 #include <linux/of.h>
40 #include <linux/of_device.h>
41 #include <linux/gcd.h>
42 
43 #include <linux/spi/spi.h>
44 
45 #include <linux/platform_data/spi-omap2-mcspi.h>
46 
47 #define OMAP2_MCSPI_MAX_FREQ		48000000
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 
93 #define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
94 #define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
95 #define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
96 #define OMAP2_MCSPI_CHSTAT_TXFFE	BIT(3)
97 
98 #define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
99 
100 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
101 
102 /* We have 2 DMA channels per CS, one for RX and one for TX */
103 struct omap2_mcspi_dma {
104 	struct dma_chan *dma_tx;
105 	struct dma_chan *dma_rx;
106 
107 	int dma_tx_sync_dev;
108 	int dma_rx_sync_dev;
109 
110 	struct completion dma_tx_completion;
111 	struct completion dma_rx_completion;
112 
113 	char dma_rx_ch_name[14];
114 	char dma_tx_ch_name[14];
115 };
116 
117 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
118  * cache operations; better heuristics consider wordsize and bitrate.
119  */
120 #define DMA_MIN_BYTES			160
121 
122 
123 /*
124  * Used for context save and restore, structure members to be updated whenever
125  * corresponding registers are modified.
126  */
127 struct omap2_mcspi_regs {
128 	u32 modulctrl;
129 	u32 wakeupenable;
130 	struct list_head cs;
131 };
132 
133 struct omap2_mcspi {
134 	struct spi_master	*master;
135 	/* Virtual base address of the controller */
136 	void __iomem		*base;
137 	unsigned long		phys;
138 	/* SPI1 has 4 channels, while SPI2 has 2 */
139 	struct omap2_mcspi_dma	*dma_channels;
140 	struct device		*dev;
141 	struct omap2_mcspi_regs ctx;
142 	int			fifo_depth;
143 	unsigned int		pin_dir:1;
144 };
145 
146 struct omap2_mcspi_cs {
147 	void __iomem		*base;
148 	unsigned long		phys;
149 	int			word_len;
150 	struct list_head	node;
151 	/* Context save and restore shadow register */
152 	u32			chconf0;
153 };
154 
155 static inline void mcspi_write_reg(struct spi_master *master,
156 		int idx, u32 val)
157 {
158 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
159 
160 	__raw_writel(val, mcspi->base + idx);
161 }
162 
163 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
164 {
165 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
166 
167 	return __raw_readl(mcspi->base + idx);
168 }
169 
170 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
171 		int idx, u32 val)
172 {
173 	struct omap2_mcspi_cs	*cs = spi->controller_state;
174 
175 	__raw_writel(val, cs->base +  idx);
176 }
177 
178 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
179 {
180 	struct omap2_mcspi_cs	*cs = spi->controller_state;
181 
182 	return __raw_readl(cs->base + idx);
183 }
184 
185 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
186 {
187 	struct omap2_mcspi_cs *cs = spi->controller_state;
188 
189 	return cs->chconf0;
190 }
191 
192 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
193 {
194 	struct omap2_mcspi_cs *cs = spi->controller_state;
195 
196 	cs->chconf0 = val;
197 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
198 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
199 }
200 
201 static inline int mcspi_bytes_per_word(int word_len)
202 {
203 	if (word_len <= 8)
204 		return 1;
205 	else if (word_len <= 16)
206 		return 2;
207 	else /* word_len <= 32 */
208 		return 4;
209 }
210 
211 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
212 		int is_read, int enable)
213 {
214 	u32 l, rw;
215 
216 	l = mcspi_cached_chconf0(spi);
217 
218 	if (is_read) /* 1 is read, 0 write */
219 		rw = OMAP2_MCSPI_CHCONF_DMAR;
220 	else
221 		rw = OMAP2_MCSPI_CHCONF_DMAW;
222 
223 	if (enable)
224 		l |= rw;
225 	else
226 		l &= ~rw;
227 
228 	mcspi_write_chconf0(spi, l);
229 }
230 
231 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
232 {
233 	u32 l;
234 
235 	l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
236 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
237 	/* Flash post-writes */
238 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
239 }
240 
241 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
242 {
243 	u32 l;
244 
245 	l = mcspi_cached_chconf0(spi);
246 	if (cs_active)
247 		l |= OMAP2_MCSPI_CHCONF_FORCE;
248 	else
249 		l &= ~OMAP2_MCSPI_CHCONF_FORCE;
250 
251 	mcspi_write_chconf0(spi, l);
252 }
253 
254 static void omap2_mcspi_set_master_mode(struct spi_master *master)
255 {
256 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
257 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
258 	u32 l;
259 
260 	/*
261 	 * Setup when switching from (reset default) slave mode
262 	 * to single-channel master mode
263 	 */
264 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
265 	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
266 	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
267 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
268 
269 	ctx->modulctrl = l;
270 }
271 
272 static void omap2_mcspi_set_fifo(const struct spi_device *spi,
273 				struct spi_transfer *t, int enable)
274 {
275 	struct spi_master *master = spi->master;
276 	struct omap2_mcspi_cs *cs = spi->controller_state;
277 	struct omap2_mcspi *mcspi;
278 	unsigned int wcnt;
279 	int max_fifo_depth, fifo_depth, bytes_per_word;
280 	u32 chconf, xferlevel;
281 
282 	mcspi = spi_master_get_devdata(master);
283 
284 	chconf = mcspi_cached_chconf0(spi);
285 	if (enable) {
286 		bytes_per_word = mcspi_bytes_per_word(cs->word_len);
287 		if (t->len % bytes_per_word != 0)
288 			goto disable_fifo;
289 
290 		if (t->rx_buf != NULL && t->tx_buf != NULL)
291 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH / 2;
292 		else
293 			max_fifo_depth = OMAP2_MCSPI_MAX_FIFODEPTH;
294 
295 		fifo_depth = gcd(t->len, max_fifo_depth);
296 		if (fifo_depth < 2 || fifo_depth % bytes_per_word != 0)
297 			goto disable_fifo;
298 
299 		wcnt = t->len / bytes_per_word;
300 		if (wcnt > OMAP2_MCSPI_MAX_FIFOWCNT)
301 			goto disable_fifo;
302 
303 		xferlevel = wcnt << 16;
304 		if (t->rx_buf != NULL) {
305 			chconf |= OMAP2_MCSPI_CHCONF_FFER;
306 			xferlevel |= (fifo_depth - 1) << 8;
307 		}
308 		if (t->tx_buf != NULL) {
309 			chconf |= OMAP2_MCSPI_CHCONF_FFET;
310 			xferlevel |= fifo_depth - 1;
311 		}
312 
313 		mcspi_write_reg(master, OMAP2_MCSPI_XFERLEVEL, xferlevel);
314 		mcspi_write_chconf0(spi, chconf);
315 		mcspi->fifo_depth = fifo_depth;
316 
317 		return;
318 	}
319 
320 disable_fifo:
321 	if (t->rx_buf != NULL)
322 		chconf &= ~OMAP2_MCSPI_CHCONF_FFER;
323 	else
324 		chconf &= ~OMAP2_MCSPI_CHCONF_FFET;
325 
326 	mcspi_write_chconf0(spi, chconf);
327 	mcspi->fifo_depth = 0;
328 }
329 
330 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
331 {
332 	struct spi_master	*spi_cntrl = mcspi->master;
333 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
334 	struct omap2_mcspi_cs	*cs;
335 
336 	/* McSPI: context restore */
337 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
338 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
339 
340 	list_for_each_entry(cs, &ctx->cs, node)
341 		__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
342 }
343 
344 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
345 {
346 	unsigned long timeout;
347 
348 	timeout = jiffies + msecs_to_jiffies(1000);
349 	while (!(__raw_readl(reg) & bit)) {
350 		if (time_after(jiffies, timeout)) {
351 			if (!(__raw_readl(reg) & bit))
352 				return -ETIMEDOUT;
353 			else
354 				return 0;
355 		}
356 		cpu_relax();
357 	}
358 	return 0;
359 }
360 
361 static void omap2_mcspi_rx_callback(void *data)
362 {
363 	struct spi_device *spi = data;
364 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
365 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
366 
367 	/* We must disable the DMA RX request */
368 	omap2_mcspi_set_dma_req(spi, 1, 0);
369 
370 	complete(&mcspi_dma->dma_rx_completion);
371 }
372 
373 static void omap2_mcspi_tx_callback(void *data)
374 {
375 	struct spi_device *spi = data;
376 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
377 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
378 
379 	/* We must disable the DMA TX request */
380 	omap2_mcspi_set_dma_req(spi, 0, 0);
381 
382 	complete(&mcspi_dma->dma_tx_completion);
383 }
384 
385 static void omap2_mcspi_tx_dma(struct spi_device *spi,
386 				struct spi_transfer *xfer,
387 				struct dma_slave_config cfg)
388 {
389 	struct omap2_mcspi	*mcspi;
390 	struct omap2_mcspi_dma  *mcspi_dma;
391 	unsigned int		count;
392 
393 	mcspi = spi_master_get_devdata(spi->master);
394 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
395 	count = xfer->len;
396 
397 	if (mcspi_dma->dma_tx) {
398 		struct dma_async_tx_descriptor *tx;
399 		struct scatterlist sg;
400 
401 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
402 
403 		sg_init_table(&sg, 1);
404 		sg_dma_address(&sg) = xfer->tx_dma;
405 		sg_dma_len(&sg) = xfer->len;
406 
407 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
408 		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
409 		if (tx) {
410 			tx->callback = omap2_mcspi_tx_callback;
411 			tx->callback_param = spi;
412 			dmaengine_submit(tx);
413 		} else {
414 			/* FIXME: fall back to PIO? */
415 		}
416 	}
417 	dma_async_issue_pending(mcspi_dma->dma_tx);
418 	omap2_mcspi_set_dma_req(spi, 0, 1);
419 
420 }
421 
422 static unsigned
423 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
424 				struct dma_slave_config cfg,
425 				unsigned es)
426 {
427 	struct omap2_mcspi	*mcspi;
428 	struct omap2_mcspi_dma  *mcspi_dma;
429 	unsigned int		count, dma_count;
430 	u32			l;
431 	int			elements = 0;
432 	int			word_len, element_count;
433 	struct omap2_mcspi_cs	*cs = spi->controller_state;
434 	mcspi = spi_master_get_devdata(spi->master);
435 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
436 	count = xfer->len;
437 	dma_count = xfer->len;
438 
439 	if (mcspi->fifo_depth == 0)
440 		dma_count -= es;
441 
442 	word_len = cs->word_len;
443 	l = mcspi_cached_chconf0(spi);
444 
445 	if (word_len <= 8)
446 		element_count = count;
447 	else if (word_len <= 16)
448 		element_count = count >> 1;
449 	else /* word_len <= 32 */
450 		element_count = count >> 2;
451 
452 	if (mcspi_dma->dma_rx) {
453 		struct dma_async_tx_descriptor *tx;
454 		struct scatterlist sg;
455 
456 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
457 
458 		if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
459 			dma_count -= es;
460 
461 		sg_init_table(&sg, 1);
462 		sg_dma_address(&sg) = xfer->rx_dma;
463 		sg_dma_len(&sg) = dma_count;
464 
465 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
466 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
467 				DMA_CTRL_ACK);
468 		if (tx) {
469 			tx->callback = omap2_mcspi_rx_callback;
470 			tx->callback_param = spi;
471 			dmaengine_submit(tx);
472 		} else {
473 				/* FIXME: fall back to PIO? */
474 		}
475 	}
476 
477 	dma_async_issue_pending(mcspi_dma->dma_rx);
478 	omap2_mcspi_set_dma_req(spi, 1, 1);
479 
480 	wait_for_completion(&mcspi_dma->dma_rx_completion);
481 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
482 			 DMA_FROM_DEVICE);
483 
484 	if (mcspi->fifo_depth > 0)
485 		return count;
486 
487 	omap2_mcspi_set_enable(spi, 0);
488 
489 	elements = element_count - 1;
490 
491 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
492 		elements--;
493 
494 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
495 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
496 			u32 w;
497 
498 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
499 			if (word_len <= 8)
500 				((u8 *)xfer->rx_buf)[elements++] = w;
501 			else if (word_len <= 16)
502 				((u16 *)xfer->rx_buf)[elements++] = w;
503 			else /* word_len <= 32 */
504 				((u32 *)xfer->rx_buf)[elements++] = w;
505 		} else {
506 			int bytes_per_word = mcspi_bytes_per_word(word_len);
507 			dev_err(&spi->dev, "DMA RX penultimate word empty\n");
508 			count -= (bytes_per_word << 1);
509 			omap2_mcspi_set_enable(spi, 1);
510 			return count;
511 		}
512 	}
513 	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
514 				& OMAP2_MCSPI_CHSTAT_RXS)) {
515 		u32 w;
516 
517 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
518 		if (word_len <= 8)
519 			((u8 *)xfer->rx_buf)[elements] = w;
520 		else if (word_len <= 16)
521 			((u16 *)xfer->rx_buf)[elements] = w;
522 		else /* word_len <= 32 */
523 			((u32 *)xfer->rx_buf)[elements] = w;
524 	} else {
525 		dev_err(&spi->dev, "DMA RX last word empty\n");
526 		count -= mcspi_bytes_per_word(word_len);
527 	}
528 	omap2_mcspi_set_enable(spi, 1);
529 	return count;
530 }
531 
532 static unsigned
533 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
534 {
535 	struct omap2_mcspi	*mcspi;
536 	struct omap2_mcspi_cs	*cs = spi->controller_state;
537 	struct omap2_mcspi_dma  *mcspi_dma;
538 	unsigned int		count;
539 	u32			l;
540 	u8			*rx;
541 	const u8		*tx;
542 	struct dma_slave_config	cfg;
543 	enum dma_slave_buswidth width;
544 	unsigned es;
545 	u32			burst;
546 	void __iomem		*chstat_reg;
547 	void __iomem            *irqstat_reg;
548 	int			wait_res;
549 
550 	mcspi = spi_master_get_devdata(spi->master);
551 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
552 	l = mcspi_cached_chconf0(spi);
553 
554 
555 	if (cs->word_len <= 8) {
556 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
557 		es = 1;
558 	} else if (cs->word_len <= 16) {
559 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
560 		es = 2;
561 	} else {
562 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
563 		es = 4;
564 	}
565 
566 	count = xfer->len;
567 	burst = 1;
568 
569 	if (mcspi->fifo_depth > 0) {
570 		if (count > mcspi->fifo_depth)
571 			burst = mcspi->fifo_depth / es;
572 		else
573 			burst = count / es;
574 	}
575 
576 	memset(&cfg, 0, sizeof(cfg));
577 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
578 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
579 	cfg.src_addr_width = width;
580 	cfg.dst_addr_width = width;
581 	cfg.src_maxburst = burst;
582 	cfg.dst_maxburst = burst;
583 
584 	rx = xfer->rx_buf;
585 	tx = xfer->tx_buf;
586 
587 	if (tx != NULL)
588 		omap2_mcspi_tx_dma(spi, xfer, cfg);
589 
590 	if (rx != NULL)
591 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
592 
593 	if (tx != NULL) {
594 		wait_for_completion(&mcspi_dma->dma_tx_completion);
595 		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
596 				 DMA_TO_DEVICE);
597 
598 		if (mcspi->fifo_depth > 0) {
599 			irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
600 
601 			if (mcspi_wait_for_reg_bit(irqstat_reg,
602 						OMAP2_MCSPI_IRQSTATUS_EOW) < 0)
603 				dev_err(&spi->dev, "EOW timed out\n");
604 
605 			mcspi_write_reg(mcspi->master, OMAP2_MCSPI_IRQSTATUS,
606 					OMAP2_MCSPI_IRQSTATUS_EOW);
607 		}
608 
609 		/* for TX_ONLY mode, be sure all words have shifted out */
610 		if (rx == NULL) {
611 			chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
612 			if (mcspi->fifo_depth > 0) {
613 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
614 						OMAP2_MCSPI_CHSTAT_TXFFE);
615 				if (wait_res < 0)
616 					dev_err(&spi->dev, "TXFFE timed out\n");
617 			} else {
618 				wait_res = mcspi_wait_for_reg_bit(chstat_reg,
619 						OMAP2_MCSPI_CHSTAT_TXS);
620 				if (wait_res < 0)
621 					dev_err(&spi->dev, "TXS timed out\n");
622 			}
623 			if (wait_res >= 0 &&
624 				(mcspi_wait_for_reg_bit(chstat_reg,
625 					OMAP2_MCSPI_CHSTAT_EOT) < 0))
626 				dev_err(&spi->dev, "EOT timed out\n");
627 		}
628 	}
629 	return count;
630 }
631 
632 static unsigned
633 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
634 {
635 	struct omap2_mcspi	*mcspi;
636 	struct omap2_mcspi_cs	*cs = spi->controller_state;
637 	unsigned int		count, c;
638 	u32			l;
639 	void __iomem		*base = cs->base;
640 	void __iomem		*tx_reg;
641 	void __iomem		*rx_reg;
642 	void __iomem		*chstat_reg;
643 	int			word_len;
644 
645 	mcspi = spi_master_get_devdata(spi->master);
646 	count = xfer->len;
647 	c = count;
648 	word_len = cs->word_len;
649 
650 	l = mcspi_cached_chconf0(spi);
651 
652 	/* We store the pre-calculated register addresses on stack to speed
653 	 * up the transfer loop. */
654 	tx_reg		= base + OMAP2_MCSPI_TX0;
655 	rx_reg		= base + OMAP2_MCSPI_RX0;
656 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
657 
658 	if (c < (word_len>>3))
659 		return 0;
660 
661 	if (word_len <= 8) {
662 		u8		*rx;
663 		const u8	*tx;
664 
665 		rx = xfer->rx_buf;
666 		tx = xfer->tx_buf;
667 
668 		do {
669 			c -= 1;
670 			if (tx != NULL) {
671 				if (mcspi_wait_for_reg_bit(chstat_reg,
672 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
673 					dev_err(&spi->dev, "TXS timed out\n");
674 					goto out;
675 				}
676 				dev_vdbg(&spi->dev, "write-%d %02x\n",
677 						word_len, *tx);
678 				__raw_writel(*tx++, tx_reg);
679 			}
680 			if (rx != NULL) {
681 				if (mcspi_wait_for_reg_bit(chstat_reg,
682 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
683 					dev_err(&spi->dev, "RXS timed out\n");
684 					goto out;
685 				}
686 
687 				if (c == 1 && tx == NULL &&
688 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
689 					omap2_mcspi_set_enable(spi, 0);
690 					*rx++ = __raw_readl(rx_reg);
691 					dev_vdbg(&spi->dev, "read-%d %02x\n",
692 						    word_len, *(rx - 1));
693 					if (mcspi_wait_for_reg_bit(chstat_reg,
694 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
695 						dev_err(&spi->dev,
696 							"RXS timed out\n");
697 						goto out;
698 					}
699 					c = 0;
700 				} else if (c == 0 && tx == NULL) {
701 					omap2_mcspi_set_enable(spi, 0);
702 				}
703 
704 				*rx++ = __raw_readl(rx_reg);
705 				dev_vdbg(&spi->dev, "read-%d %02x\n",
706 						word_len, *(rx - 1));
707 			}
708 		} while (c);
709 	} else if (word_len <= 16) {
710 		u16		*rx;
711 		const u16	*tx;
712 
713 		rx = xfer->rx_buf;
714 		tx = xfer->tx_buf;
715 		do {
716 			c -= 2;
717 			if (tx != NULL) {
718 				if (mcspi_wait_for_reg_bit(chstat_reg,
719 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
720 					dev_err(&spi->dev, "TXS timed out\n");
721 					goto out;
722 				}
723 				dev_vdbg(&spi->dev, "write-%d %04x\n",
724 						word_len, *tx);
725 				__raw_writel(*tx++, tx_reg);
726 			}
727 			if (rx != NULL) {
728 				if (mcspi_wait_for_reg_bit(chstat_reg,
729 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
730 					dev_err(&spi->dev, "RXS timed out\n");
731 					goto out;
732 				}
733 
734 				if (c == 2 && tx == NULL &&
735 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
736 					omap2_mcspi_set_enable(spi, 0);
737 					*rx++ = __raw_readl(rx_reg);
738 					dev_vdbg(&spi->dev, "read-%d %04x\n",
739 						    word_len, *(rx - 1));
740 					if (mcspi_wait_for_reg_bit(chstat_reg,
741 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
742 						dev_err(&spi->dev,
743 							"RXS timed out\n");
744 						goto out;
745 					}
746 					c = 0;
747 				} else if (c == 0 && tx == NULL) {
748 					omap2_mcspi_set_enable(spi, 0);
749 				}
750 
751 				*rx++ = __raw_readl(rx_reg);
752 				dev_vdbg(&spi->dev, "read-%d %04x\n",
753 						word_len, *(rx - 1));
754 			}
755 		} while (c >= 2);
756 	} else if (word_len <= 32) {
757 		u32		*rx;
758 		const u32	*tx;
759 
760 		rx = xfer->rx_buf;
761 		tx = xfer->tx_buf;
762 		do {
763 			c -= 4;
764 			if (tx != NULL) {
765 				if (mcspi_wait_for_reg_bit(chstat_reg,
766 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
767 					dev_err(&spi->dev, "TXS timed out\n");
768 					goto out;
769 				}
770 				dev_vdbg(&spi->dev, "write-%d %08x\n",
771 						word_len, *tx);
772 				__raw_writel(*tx++, tx_reg);
773 			}
774 			if (rx != NULL) {
775 				if (mcspi_wait_for_reg_bit(chstat_reg,
776 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
777 					dev_err(&spi->dev, "RXS timed out\n");
778 					goto out;
779 				}
780 
781 				if (c == 4 && tx == NULL &&
782 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
783 					omap2_mcspi_set_enable(spi, 0);
784 					*rx++ = __raw_readl(rx_reg);
785 					dev_vdbg(&spi->dev, "read-%d %08x\n",
786 						    word_len, *(rx - 1));
787 					if (mcspi_wait_for_reg_bit(chstat_reg,
788 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
789 						dev_err(&spi->dev,
790 							"RXS timed out\n");
791 						goto out;
792 					}
793 					c = 0;
794 				} else if (c == 0 && tx == NULL) {
795 					omap2_mcspi_set_enable(spi, 0);
796 				}
797 
798 				*rx++ = __raw_readl(rx_reg);
799 				dev_vdbg(&spi->dev, "read-%d %08x\n",
800 						word_len, *(rx - 1));
801 			}
802 		} while (c >= 4);
803 	}
804 
805 	/* for TX_ONLY mode, be sure all words have shifted out */
806 	if (xfer->rx_buf == NULL) {
807 		if (mcspi_wait_for_reg_bit(chstat_reg,
808 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
809 			dev_err(&spi->dev, "TXS timed out\n");
810 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
811 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
812 			dev_err(&spi->dev, "EOT timed out\n");
813 
814 		/* disable chan to purge rx datas received in TX_ONLY transfer,
815 		 * otherwise these rx datas will affect the direct following
816 		 * RX_ONLY transfer.
817 		 */
818 		omap2_mcspi_set_enable(spi, 0);
819 	}
820 out:
821 	omap2_mcspi_set_enable(spi, 1);
822 	return count - c;
823 }
824 
825 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
826 {
827 	u32 div;
828 
829 	for (div = 0; div < 15; div++)
830 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
831 			return div;
832 
833 	return 15;
834 }
835 
836 /* called only when no transfer is active to this device */
837 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
838 		struct spi_transfer *t)
839 {
840 	struct omap2_mcspi_cs *cs = spi->controller_state;
841 	struct omap2_mcspi *mcspi;
842 	struct spi_master *spi_cntrl;
843 	u32 l = 0, div = 0;
844 	u8 word_len = spi->bits_per_word;
845 	u32 speed_hz = spi->max_speed_hz;
846 
847 	mcspi = spi_master_get_devdata(spi->master);
848 	spi_cntrl = mcspi->master;
849 
850 	if (t != NULL && t->bits_per_word)
851 		word_len = t->bits_per_word;
852 
853 	cs->word_len = word_len;
854 
855 	if (t && t->speed_hz)
856 		speed_hz = t->speed_hz;
857 
858 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
859 	div = omap2_mcspi_calc_divisor(speed_hz);
860 
861 	l = mcspi_cached_chconf0(spi);
862 
863 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
864 	 * REVISIT: this controller could support SPI_3WIRE mode.
865 	 */
866 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
867 		l &= ~OMAP2_MCSPI_CHCONF_IS;
868 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
869 		l |= OMAP2_MCSPI_CHCONF_DPE0;
870 	} else {
871 		l |= OMAP2_MCSPI_CHCONF_IS;
872 		l |= OMAP2_MCSPI_CHCONF_DPE1;
873 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
874 	}
875 
876 	/* wordlength */
877 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
878 	l |= (word_len - 1) << 7;
879 
880 	/* set chipselect polarity; manage with FORCE */
881 	if (!(spi->mode & SPI_CS_HIGH))
882 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
883 	else
884 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
885 
886 	/* set clock divisor */
887 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
888 	l |= div << 2;
889 
890 	/* set SPI mode 0..3 */
891 	if (spi->mode & SPI_CPOL)
892 		l |= OMAP2_MCSPI_CHCONF_POL;
893 	else
894 		l &= ~OMAP2_MCSPI_CHCONF_POL;
895 	if (spi->mode & SPI_CPHA)
896 		l |= OMAP2_MCSPI_CHCONF_PHA;
897 	else
898 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
899 
900 	mcspi_write_chconf0(spi, l);
901 
902 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
903 			OMAP2_MCSPI_MAX_FREQ >> div,
904 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
905 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
906 
907 	return 0;
908 }
909 
910 /*
911  * Note that we currently allow DMA only if we get a channel
912  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
913  */
914 static int omap2_mcspi_request_dma(struct spi_device *spi)
915 {
916 	struct spi_master	*master = spi->master;
917 	struct omap2_mcspi	*mcspi;
918 	struct omap2_mcspi_dma	*mcspi_dma;
919 	dma_cap_mask_t mask;
920 	unsigned sig;
921 
922 	mcspi = spi_master_get_devdata(master);
923 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
924 
925 	init_completion(&mcspi_dma->dma_rx_completion);
926 	init_completion(&mcspi_dma->dma_tx_completion);
927 
928 	dma_cap_zero(mask);
929 	dma_cap_set(DMA_SLAVE, mask);
930 	sig = mcspi_dma->dma_rx_sync_dev;
931 
932 	mcspi_dma->dma_rx =
933 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
934 						 &sig, &master->dev,
935 						 mcspi_dma->dma_rx_ch_name);
936 	if (!mcspi_dma->dma_rx)
937 		goto no_dma;
938 
939 	sig = mcspi_dma->dma_tx_sync_dev;
940 	mcspi_dma->dma_tx =
941 		dma_request_slave_channel_compat(mask, omap_dma_filter_fn,
942 						 &sig, &master->dev,
943 						 mcspi_dma->dma_tx_ch_name);
944 
945 	if (!mcspi_dma->dma_tx) {
946 		dma_release_channel(mcspi_dma->dma_rx);
947 		mcspi_dma->dma_rx = NULL;
948 		goto no_dma;
949 	}
950 
951 	return 0;
952 
953 no_dma:
954 	dev_warn(&spi->dev, "not using DMA for McSPI\n");
955 	return -EAGAIN;
956 }
957 
958 static int omap2_mcspi_setup(struct spi_device *spi)
959 {
960 	int			ret;
961 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
962 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
963 	struct omap2_mcspi_dma	*mcspi_dma;
964 	struct omap2_mcspi_cs	*cs = spi->controller_state;
965 
966 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
967 
968 	if (!cs) {
969 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
970 		if (!cs)
971 			return -ENOMEM;
972 		cs->base = mcspi->base + spi->chip_select * 0x14;
973 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
974 		cs->chconf0 = 0;
975 		spi->controller_state = cs;
976 		/* Link this to context save list */
977 		list_add_tail(&cs->node, &ctx->cs);
978 	}
979 
980 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
981 		ret = omap2_mcspi_request_dma(spi);
982 		if (ret < 0 && ret != -EAGAIN)
983 			return ret;
984 	}
985 
986 	ret = pm_runtime_get_sync(mcspi->dev);
987 	if (ret < 0)
988 		return ret;
989 
990 	ret = omap2_mcspi_setup_transfer(spi, NULL);
991 	pm_runtime_mark_last_busy(mcspi->dev);
992 	pm_runtime_put_autosuspend(mcspi->dev);
993 
994 	return ret;
995 }
996 
997 static void omap2_mcspi_cleanup(struct spi_device *spi)
998 {
999 	struct omap2_mcspi	*mcspi;
1000 	struct omap2_mcspi_dma	*mcspi_dma;
1001 	struct omap2_mcspi_cs	*cs;
1002 
1003 	mcspi = spi_master_get_devdata(spi->master);
1004 
1005 	if (spi->controller_state) {
1006 		/* Unlink controller state from context save list */
1007 		cs = spi->controller_state;
1008 		list_del(&cs->node);
1009 
1010 		kfree(cs);
1011 	}
1012 
1013 	if (spi->chip_select < spi->master->num_chipselect) {
1014 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
1015 
1016 		if (mcspi_dma->dma_rx) {
1017 			dma_release_channel(mcspi_dma->dma_rx);
1018 			mcspi_dma->dma_rx = NULL;
1019 		}
1020 		if (mcspi_dma->dma_tx) {
1021 			dma_release_channel(mcspi_dma->dma_tx);
1022 			mcspi_dma->dma_tx = NULL;
1023 		}
1024 	}
1025 }
1026 
1027 static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
1028 {
1029 
1030 	/* We only enable one channel at a time -- the one whose message is
1031 	 * -- although this controller would gladly
1032 	 * arbitrate among multiple channels.  This corresponds to "single
1033 	 * channel" master mode.  As a side effect, we need to manage the
1034 	 * chipselect with the FORCE bit ... CS != channel enable.
1035 	 */
1036 
1037 	struct spi_device		*spi;
1038 	struct spi_transfer		*t = NULL;
1039 	struct spi_master		*master;
1040 	struct omap2_mcspi_dma		*mcspi_dma;
1041 	int				cs_active = 0;
1042 	struct omap2_mcspi_cs		*cs;
1043 	struct omap2_mcspi_device_config *cd;
1044 	int				par_override = 0;
1045 	int				status = 0;
1046 	u32				chconf;
1047 
1048 	spi = m->spi;
1049 	master = spi->master;
1050 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1051 	cs = spi->controller_state;
1052 	cd = spi->controller_data;
1053 
1054 	omap2_mcspi_set_enable(spi, 0);
1055 	list_for_each_entry(t, &m->transfers, transfer_list) {
1056 		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
1057 			status = -EINVAL;
1058 			break;
1059 		}
1060 		if (par_override || t->speed_hz || t->bits_per_word) {
1061 			par_override = 1;
1062 			status = omap2_mcspi_setup_transfer(spi, t);
1063 			if (status < 0)
1064 				break;
1065 			if (!t->speed_hz && !t->bits_per_word)
1066 				par_override = 0;
1067 		}
1068 		if (cd && cd->cs_per_word) {
1069 			chconf = mcspi->ctx.modulctrl;
1070 			chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
1071 			mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1072 			mcspi->ctx.modulctrl =
1073 				mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1074 		}
1075 
1076 
1077 		if (!cs_active) {
1078 			omap2_mcspi_force_cs(spi, 1);
1079 			cs_active = 1;
1080 		}
1081 
1082 		chconf = mcspi_cached_chconf0(spi);
1083 		chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
1084 		chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
1085 
1086 		if (t->tx_buf == NULL)
1087 			chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
1088 		else if (t->rx_buf == NULL)
1089 			chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
1090 
1091 		if (cd && cd->turbo_mode && t->tx_buf == NULL) {
1092 			/* Turbo mode is for more than one word */
1093 			if (t->len > ((cs->word_len + 7) >> 3))
1094 				chconf |= OMAP2_MCSPI_CHCONF_TURBO;
1095 		}
1096 
1097 		mcspi_write_chconf0(spi, chconf);
1098 
1099 		if (t->len) {
1100 			unsigned	count;
1101 
1102 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1103 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1104 				omap2_mcspi_set_fifo(spi, t, 1);
1105 
1106 			omap2_mcspi_set_enable(spi, 1);
1107 
1108 			/* RX_ONLY mode needs dummy data in TX reg */
1109 			if (t->tx_buf == NULL)
1110 				__raw_writel(0, cs->base
1111 						+ OMAP2_MCSPI_TX0);
1112 
1113 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1114 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1115 				count = omap2_mcspi_txrx_dma(spi, t);
1116 			else
1117 				count = omap2_mcspi_txrx_pio(spi, t);
1118 			m->actual_length += count;
1119 
1120 			if (count != t->len) {
1121 				status = -EIO;
1122 				break;
1123 			}
1124 		}
1125 
1126 		if (t->delay_usecs)
1127 			udelay(t->delay_usecs);
1128 
1129 		/* ignore the "leave it on after last xfer" hint */
1130 		if (t->cs_change) {
1131 			omap2_mcspi_force_cs(spi, 0);
1132 			cs_active = 0;
1133 		}
1134 
1135 		omap2_mcspi_set_enable(spi, 0);
1136 
1137 		if (mcspi->fifo_depth > 0)
1138 			omap2_mcspi_set_fifo(spi, t, 0);
1139 	}
1140 	/* Restore defaults if they were overriden */
1141 	if (par_override) {
1142 		par_override = 0;
1143 		status = omap2_mcspi_setup_transfer(spi, NULL);
1144 	}
1145 
1146 	if (cs_active)
1147 		omap2_mcspi_force_cs(spi, 0);
1148 
1149 	if (cd && cd->cs_per_word) {
1150 		chconf = mcspi->ctx.modulctrl;
1151 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1152 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1153 		mcspi->ctx.modulctrl =
1154 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1155 	}
1156 
1157 	omap2_mcspi_set_enable(spi, 0);
1158 
1159 	if (mcspi->fifo_depth > 0 && t)
1160 		omap2_mcspi_set_fifo(spi, t, 0);
1161 
1162 	m->status = status;
1163 }
1164 
1165 static int omap2_mcspi_transfer_one_message(struct spi_master *master,
1166 		struct spi_message *m)
1167 {
1168 	struct spi_device	*spi;
1169 	struct omap2_mcspi	*mcspi;
1170 	struct omap2_mcspi_dma	*mcspi_dma;
1171 	struct spi_transfer	*t;
1172 
1173 	spi = m->spi;
1174 	mcspi = spi_master_get_devdata(master);
1175 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1176 	m->actual_length = 0;
1177 	m->status = 0;
1178 
1179 	/* reject invalid messages and transfers */
1180 	if (list_empty(&m->transfers))
1181 		return -EINVAL;
1182 	list_for_each_entry(t, &m->transfers, transfer_list) {
1183 		const void	*tx_buf = t->tx_buf;
1184 		void		*rx_buf = t->rx_buf;
1185 		unsigned	len = t->len;
1186 
1187 		if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
1188 				|| (len && !(rx_buf || tx_buf))) {
1189 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1190 					t->speed_hz,
1191 					len,
1192 					tx_buf ? "tx" : "",
1193 					rx_buf ? "rx" : "",
1194 					t->bits_per_word);
1195 			return -EINVAL;
1196 		}
1197 		if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
1198 			dev_dbg(mcspi->dev, "speed_hz %d below minimum %d Hz\n",
1199 					t->speed_hz,
1200 					OMAP2_MCSPI_MAX_FREQ >> 15);
1201 			return -EINVAL;
1202 		}
1203 
1204 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1205 			continue;
1206 
1207 		if (mcspi_dma->dma_tx && tx_buf != NULL) {
1208 			t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1209 					len, DMA_TO_DEVICE);
1210 			if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1211 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1212 						'T', len);
1213 				return -EINVAL;
1214 			}
1215 		}
1216 		if (mcspi_dma->dma_rx && rx_buf != NULL) {
1217 			t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1218 					DMA_FROM_DEVICE);
1219 			if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1220 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1221 						'R', len);
1222 				if (tx_buf != NULL)
1223 					dma_unmap_single(mcspi->dev, t->tx_dma,
1224 							len, DMA_TO_DEVICE);
1225 				return -EINVAL;
1226 			}
1227 		}
1228 	}
1229 
1230 	omap2_mcspi_work(mcspi, m);
1231 	spi_finalize_current_message(master);
1232 	return 0;
1233 }
1234 
1235 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1236 {
1237 	struct spi_master	*master = mcspi->master;
1238 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1239 	int			ret = 0;
1240 
1241 	ret = pm_runtime_get_sync(mcspi->dev);
1242 	if (ret < 0)
1243 		return ret;
1244 
1245 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1246 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1247 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1248 
1249 	omap2_mcspi_set_master_mode(master);
1250 	pm_runtime_mark_last_busy(mcspi->dev);
1251 	pm_runtime_put_autosuspend(mcspi->dev);
1252 	return 0;
1253 }
1254 
1255 static int omap_mcspi_runtime_resume(struct device *dev)
1256 {
1257 	struct omap2_mcspi	*mcspi;
1258 	struct spi_master	*master;
1259 
1260 	master = dev_get_drvdata(dev);
1261 	mcspi = spi_master_get_devdata(master);
1262 	omap2_mcspi_restore_ctx(mcspi);
1263 
1264 	return 0;
1265 }
1266 
1267 static struct omap2_mcspi_platform_config omap2_pdata = {
1268 	.regs_offset = 0,
1269 };
1270 
1271 static struct omap2_mcspi_platform_config omap4_pdata = {
1272 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1273 };
1274 
1275 static const struct of_device_id omap_mcspi_of_match[] = {
1276 	{
1277 		.compatible = "ti,omap2-mcspi",
1278 		.data = &omap2_pdata,
1279 	},
1280 	{
1281 		.compatible = "ti,omap4-mcspi",
1282 		.data = &omap4_pdata,
1283 	},
1284 	{ },
1285 };
1286 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1287 
1288 static int omap2_mcspi_probe(struct platform_device *pdev)
1289 {
1290 	struct spi_master	*master;
1291 	const struct omap2_mcspi_platform_config *pdata;
1292 	struct omap2_mcspi	*mcspi;
1293 	struct resource		*r;
1294 	int			status = 0, i;
1295 	u32			regs_offset = 0;
1296 	static int		bus_num = 1;
1297 	struct device_node	*node = pdev->dev.of_node;
1298 	const struct of_device_id *match;
1299 
1300 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1301 	if (master == NULL) {
1302 		dev_dbg(&pdev->dev, "master allocation failed\n");
1303 		return -ENOMEM;
1304 	}
1305 
1306 	/* the spi->mode bits understood by this driver: */
1307 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1308 	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
1309 	master->setup = omap2_mcspi_setup;
1310 	master->auto_runtime_pm = true;
1311 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
1312 	master->cleanup = omap2_mcspi_cleanup;
1313 	master->dev.of_node = node;
1314 
1315 	platform_set_drvdata(pdev, master);
1316 
1317 	mcspi = spi_master_get_devdata(master);
1318 	mcspi->master = master;
1319 
1320 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1321 	if (match) {
1322 		u32 num_cs = 1; /* default number of chipselect */
1323 		pdata = match->data;
1324 
1325 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1326 		master->num_chipselect = num_cs;
1327 		master->bus_num = bus_num++;
1328 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1329 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1330 	} else {
1331 		pdata = dev_get_platdata(&pdev->dev);
1332 		master->num_chipselect = pdata->num_cs;
1333 		if (pdev->id != -1)
1334 			master->bus_num = pdev->id;
1335 		mcspi->pin_dir = pdata->pin_dir;
1336 	}
1337 	regs_offset = pdata->regs_offset;
1338 
1339 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1340 	if (r == NULL) {
1341 		status = -ENODEV;
1342 		goto free_master;
1343 	}
1344 
1345 	r->start += regs_offset;
1346 	r->end += regs_offset;
1347 	mcspi->phys = r->start;
1348 
1349 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1350 	if (IS_ERR(mcspi->base)) {
1351 		status = PTR_ERR(mcspi->base);
1352 		goto free_master;
1353 	}
1354 
1355 	mcspi->dev = &pdev->dev;
1356 
1357 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1358 
1359 	mcspi->dma_channels = kcalloc(master->num_chipselect,
1360 			sizeof(struct omap2_mcspi_dma),
1361 			GFP_KERNEL);
1362 
1363 	if (mcspi->dma_channels == NULL)
1364 		goto free_master;
1365 
1366 	for (i = 0; i < master->num_chipselect; i++) {
1367 		char *dma_rx_ch_name = mcspi->dma_channels[i].dma_rx_ch_name;
1368 		char *dma_tx_ch_name = mcspi->dma_channels[i].dma_tx_ch_name;
1369 		struct resource *dma_res;
1370 
1371 		sprintf(dma_rx_ch_name, "rx%d", i);
1372 		if (!pdev->dev.of_node) {
1373 			dma_res =
1374 				platform_get_resource_byname(pdev,
1375 							     IORESOURCE_DMA,
1376 							     dma_rx_ch_name);
1377 			if (!dma_res) {
1378 				dev_dbg(&pdev->dev,
1379 					"cannot get DMA RX channel\n");
1380 				status = -ENODEV;
1381 				break;
1382 			}
1383 
1384 			mcspi->dma_channels[i].dma_rx_sync_dev =
1385 				dma_res->start;
1386 		}
1387 		sprintf(dma_tx_ch_name, "tx%d", i);
1388 		if (!pdev->dev.of_node) {
1389 			dma_res =
1390 				platform_get_resource_byname(pdev,
1391 							     IORESOURCE_DMA,
1392 							     dma_tx_ch_name);
1393 			if (!dma_res) {
1394 				dev_dbg(&pdev->dev,
1395 					"cannot get DMA TX channel\n");
1396 				status = -ENODEV;
1397 				break;
1398 			}
1399 
1400 			mcspi->dma_channels[i].dma_tx_sync_dev =
1401 				dma_res->start;
1402 		}
1403 	}
1404 
1405 	if (status < 0)
1406 		goto dma_chnl_free;
1407 
1408 	pm_runtime_use_autosuspend(&pdev->dev);
1409 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1410 	pm_runtime_enable(&pdev->dev);
1411 
1412 	status = omap2_mcspi_master_setup(mcspi);
1413 	if (status < 0)
1414 		goto disable_pm;
1415 
1416 	status = devm_spi_register_master(&pdev->dev, master);
1417 	if (status < 0)
1418 		goto disable_pm;
1419 
1420 	return status;
1421 
1422 disable_pm:
1423 	pm_runtime_disable(&pdev->dev);
1424 dma_chnl_free:
1425 	kfree(mcspi->dma_channels);
1426 free_master:
1427 	spi_master_put(master);
1428 	return status;
1429 }
1430 
1431 static int omap2_mcspi_remove(struct platform_device *pdev)
1432 {
1433 	struct spi_master	*master;
1434 	struct omap2_mcspi	*mcspi;
1435 	struct omap2_mcspi_dma	*dma_channels;
1436 
1437 	master = platform_get_drvdata(pdev);
1438 	mcspi = spi_master_get_devdata(master);
1439 	dma_channels = mcspi->dma_channels;
1440 
1441 	pm_runtime_put_sync(mcspi->dev);
1442 	pm_runtime_disable(&pdev->dev);
1443 
1444 	kfree(dma_channels);
1445 
1446 	return 0;
1447 }
1448 
1449 /* work with hotplug and coldplug */
1450 MODULE_ALIAS("platform:omap2_mcspi");
1451 
1452 #ifdef	CONFIG_SUSPEND
1453 /*
1454  * When SPI wake up from off-mode, CS is in activate state. If it was in
1455  * unactive state when driver was suspend, then force it to unactive state at
1456  * wake up.
1457  */
1458 static int omap2_mcspi_resume(struct device *dev)
1459 {
1460 	struct spi_master	*master = dev_get_drvdata(dev);
1461 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1462 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1463 	struct omap2_mcspi_cs	*cs;
1464 
1465 	pm_runtime_get_sync(mcspi->dev);
1466 	list_for_each_entry(cs, &ctx->cs, node) {
1467 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1468 			/*
1469 			 * We need to toggle CS state for OMAP take this
1470 			 * change in account.
1471 			 */
1472 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1473 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1474 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1475 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1476 		}
1477 	}
1478 	pm_runtime_mark_last_busy(mcspi->dev);
1479 	pm_runtime_put_autosuspend(mcspi->dev);
1480 	return 0;
1481 }
1482 #else
1483 #define	omap2_mcspi_resume	NULL
1484 #endif
1485 
1486 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1487 	.resume = omap2_mcspi_resume,
1488 	.runtime_resume	= omap_mcspi_runtime_resume,
1489 };
1490 
1491 static struct platform_driver omap2_mcspi_driver = {
1492 	.driver = {
1493 		.name =		"omap2_mcspi",
1494 		.owner =	THIS_MODULE,
1495 		.pm =		&omap2_mcspi_pm_ops,
1496 		.of_match_table = omap_mcspi_of_match,
1497 	},
1498 	.probe =	omap2_mcspi_probe,
1499 	.remove =	omap2_mcspi_remove,
1500 };
1501 
1502 module_platform_driver(omap2_mcspi_driver);
1503 MODULE_LICENSE("GPL");
1504