xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision ee89bd6b)
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/pinctrl/consumer.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 SPI_AUTOSUSPEND_TIMEOUT		2000
49 
50 #define OMAP2_MCSPI_REVISION		0x00
51 #define OMAP2_MCSPI_SYSSTATUS		0x14
52 #define OMAP2_MCSPI_IRQSTATUS		0x18
53 #define OMAP2_MCSPI_IRQENABLE		0x1c
54 #define OMAP2_MCSPI_WAKEUPENABLE	0x20
55 #define OMAP2_MCSPI_SYST		0x24
56 #define OMAP2_MCSPI_MODULCTRL		0x28
57 
58 /* per-channel banks, 0x14 bytes each, first is: */
59 #define OMAP2_MCSPI_CHCONF0		0x2c
60 #define OMAP2_MCSPI_CHSTAT0		0x30
61 #define OMAP2_MCSPI_CHCTRL0		0x34
62 #define OMAP2_MCSPI_TX0			0x38
63 #define OMAP2_MCSPI_RX0			0x3c
64 
65 /* per-register bitmasks: */
66 
67 #define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
68 #define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
69 #define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
70 
71 #define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
72 #define OMAP2_MCSPI_CHCONF_POL		BIT(1)
73 #define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
74 #define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
75 #define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
76 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
77 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
78 #define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
79 #define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
80 #define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
81 #define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
82 #define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
83 #define OMAP2_MCSPI_CHCONF_IS		BIT(18)
84 #define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
85 #define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
86 
87 #define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
88 #define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
89 #define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
90 
91 #define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
92 
93 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
94 
95 /* We have 2 DMA channels per CS, one for RX and one for TX */
96 struct omap2_mcspi_dma {
97 	struct dma_chan *dma_tx;
98 	struct dma_chan *dma_rx;
99 
100 	int dma_tx_sync_dev;
101 	int dma_rx_sync_dev;
102 
103 	struct completion dma_tx_completion;
104 	struct completion dma_rx_completion;
105 };
106 
107 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
108  * cache operations; better heuristics consider wordsize and bitrate.
109  */
110 #define DMA_MIN_BYTES			160
111 
112 
113 /*
114  * Used for context save and restore, structure members to be updated whenever
115  * corresponding registers are modified.
116  */
117 struct omap2_mcspi_regs {
118 	u32 modulctrl;
119 	u32 wakeupenable;
120 	struct list_head cs;
121 };
122 
123 struct omap2_mcspi {
124 	struct spi_master	*master;
125 	/* Virtual base address of the controller */
126 	void __iomem		*base;
127 	unsigned long		phys;
128 	/* SPI1 has 4 channels, while SPI2 has 2 */
129 	struct omap2_mcspi_dma	*dma_channels;
130 	struct device		*dev;
131 	struct omap2_mcspi_regs ctx;
132 	unsigned int		pin_dir:1;
133 };
134 
135 struct omap2_mcspi_cs {
136 	void __iomem		*base;
137 	unsigned long		phys;
138 	int			word_len;
139 	struct list_head	node;
140 	/* Context save and restore shadow register */
141 	u32			chconf0;
142 };
143 
144 static inline void mcspi_write_reg(struct spi_master *master,
145 		int idx, u32 val)
146 {
147 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
148 
149 	__raw_writel(val, mcspi->base + idx);
150 }
151 
152 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
153 {
154 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
155 
156 	return __raw_readl(mcspi->base + idx);
157 }
158 
159 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
160 		int idx, u32 val)
161 {
162 	struct omap2_mcspi_cs	*cs = spi->controller_state;
163 
164 	__raw_writel(val, cs->base +  idx);
165 }
166 
167 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
168 {
169 	struct omap2_mcspi_cs	*cs = spi->controller_state;
170 
171 	return __raw_readl(cs->base + idx);
172 }
173 
174 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
175 {
176 	struct omap2_mcspi_cs *cs = spi->controller_state;
177 
178 	return cs->chconf0;
179 }
180 
181 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
182 {
183 	struct omap2_mcspi_cs *cs = spi->controller_state;
184 
185 	cs->chconf0 = val;
186 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
187 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
188 }
189 
190 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
191 		int is_read, int enable)
192 {
193 	u32 l, rw;
194 
195 	l = mcspi_cached_chconf0(spi);
196 
197 	if (is_read) /* 1 is read, 0 write */
198 		rw = OMAP2_MCSPI_CHCONF_DMAR;
199 	else
200 		rw = OMAP2_MCSPI_CHCONF_DMAW;
201 
202 	if (enable)
203 		l |= rw;
204 	else
205 		l &= ~rw;
206 
207 	mcspi_write_chconf0(spi, l);
208 }
209 
210 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
211 {
212 	u32 l;
213 
214 	l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
215 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
216 	/* Flash post-writes */
217 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
218 }
219 
220 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
221 {
222 	u32 l;
223 
224 	l = mcspi_cached_chconf0(spi);
225 	if (cs_active)
226 		l |= OMAP2_MCSPI_CHCONF_FORCE;
227 	else
228 		l &= ~OMAP2_MCSPI_CHCONF_FORCE;
229 
230 	mcspi_write_chconf0(spi, l);
231 }
232 
233 static void omap2_mcspi_set_master_mode(struct spi_master *master)
234 {
235 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
236 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
237 	u32 l;
238 
239 	/*
240 	 * Setup when switching from (reset default) slave mode
241 	 * to single-channel master mode
242 	 */
243 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
244 	l &= ~(OMAP2_MCSPI_MODULCTRL_STEST | OMAP2_MCSPI_MODULCTRL_MS);
245 	l |= OMAP2_MCSPI_MODULCTRL_SINGLE;
246 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
247 
248 	ctx->modulctrl = l;
249 }
250 
251 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
252 {
253 	struct spi_master	*spi_cntrl = mcspi->master;
254 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
255 	struct omap2_mcspi_cs	*cs;
256 
257 	/* McSPI: context restore */
258 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL, ctx->modulctrl);
259 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE, ctx->wakeupenable);
260 
261 	list_for_each_entry(cs, &ctx->cs, node)
262 		__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
263 }
264 
265 static int omap2_prepare_transfer(struct spi_master *master)
266 {
267 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
268 
269 	pm_runtime_get_sync(mcspi->dev);
270 	return 0;
271 }
272 
273 static int omap2_unprepare_transfer(struct spi_master *master)
274 {
275 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
276 
277 	pm_runtime_mark_last_busy(mcspi->dev);
278 	pm_runtime_put_autosuspend(mcspi->dev);
279 	return 0;
280 }
281 
282 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
283 {
284 	unsigned long timeout;
285 
286 	timeout = jiffies + msecs_to_jiffies(1000);
287 	while (!(__raw_readl(reg) & bit)) {
288 		if (time_after(jiffies, timeout)) {
289 			if (!(__raw_readl(reg) & bit))
290 				return -ETIMEDOUT;
291 			else
292 				return 0;
293 		}
294 		cpu_relax();
295 	}
296 	return 0;
297 }
298 
299 static void omap2_mcspi_rx_callback(void *data)
300 {
301 	struct spi_device *spi = data;
302 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
303 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
304 
305 	/* We must disable the DMA RX request */
306 	omap2_mcspi_set_dma_req(spi, 1, 0);
307 
308 	complete(&mcspi_dma->dma_rx_completion);
309 }
310 
311 static void omap2_mcspi_tx_callback(void *data)
312 {
313 	struct spi_device *spi = data;
314 	struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
315 	struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];
316 
317 	/* We must disable the DMA TX request */
318 	omap2_mcspi_set_dma_req(spi, 0, 0);
319 
320 	complete(&mcspi_dma->dma_tx_completion);
321 }
322 
323 static void omap2_mcspi_tx_dma(struct spi_device *spi,
324 				struct spi_transfer *xfer,
325 				struct dma_slave_config cfg)
326 {
327 	struct omap2_mcspi	*mcspi;
328 	struct omap2_mcspi_dma  *mcspi_dma;
329 	unsigned int		count;
330 
331 	mcspi = spi_master_get_devdata(spi->master);
332 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
333 	count = xfer->len;
334 
335 	if (mcspi_dma->dma_tx) {
336 		struct dma_async_tx_descriptor *tx;
337 		struct scatterlist sg;
338 
339 		dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
340 
341 		sg_init_table(&sg, 1);
342 		sg_dma_address(&sg) = xfer->tx_dma;
343 		sg_dma_len(&sg) = xfer->len;
344 
345 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
346 		DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
347 		if (tx) {
348 			tx->callback = omap2_mcspi_tx_callback;
349 			tx->callback_param = spi;
350 			dmaengine_submit(tx);
351 		} else {
352 			/* FIXME: fall back to PIO? */
353 		}
354 	}
355 	dma_async_issue_pending(mcspi_dma->dma_tx);
356 	omap2_mcspi_set_dma_req(spi, 0, 1);
357 
358 }
359 
360 static unsigned
361 omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
362 				struct dma_slave_config cfg,
363 				unsigned es)
364 {
365 	struct omap2_mcspi	*mcspi;
366 	struct omap2_mcspi_dma  *mcspi_dma;
367 	unsigned int		count;
368 	u32			l;
369 	int			elements = 0;
370 	int			word_len, element_count;
371 	struct omap2_mcspi_cs	*cs = spi->controller_state;
372 	mcspi = spi_master_get_devdata(spi->master);
373 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
374 	count = xfer->len;
375 	word_len = cs->word_len;
376 	l = mcspi_cached_chconf0(spi);
377 
378 	if (word_len <= 8)
379 		element_count = count;
380 	else if (word_len <= 16)
381 		element_count = count >> 1;
382 	else /* word_len <= 32 */
383 		element_count = count >> 2;
384 
385 	if (mcspi_dma->dma_rx) {
386 		struct dma_async_tx_descriptor *tx;
387 		struct scatterlist sg;
388 		size_t len = xfer->len - es;
389 
390 		dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
391 
392 		if (l & OMAP2_MCSPI_CHCONF_TURBO)
393 			len -= es;
394 
395 		sg_init_table(&sg, 1);
396 		sg_dma_address(&sg) = xfer->rx_dma;
397 		sg_dma_len(&sg) = len;
398 
399 		tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
400 				DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
401 				DMA_CTRL_ACK);
402 		if (tx) {
403 			tx->callback = omap2_mcspi_rx_callback;
404 			tx->callback_param = spi;
405 			dmaengine_submit(tx);
406 		} else {
407 				/* FIXME: fall back to PIO? */
408 		}
409 	}
410 
411 	dma_async_issue_pending(mcspi_dma->dma_rx);
412 	omap2_mcspi_set_dma_req(spi, 1, 1);
413 
414 	wait_for_completion(&mcspi_dma->dma_rx_completion);
415 	dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
416 			 DMA_FROM_DEVICE);
417 	omap2_mcspi_set_enable(spi, 0);
418 
419 	elements = element_count - 1;
420 
421 	if (l & OMAP2_MCSPI_CHCONF_TURBO) {
422 		elements--;
423 
424 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
425 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
426 			u32 w;
427 
428 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
429 			if (word_len <= 8)
430 				((u8 *)xfer->rx_buf)[elements++] = w;
431 			else if (word_len <= 16)
432 				((u16 *)xfer->rx_buf)[elements++] = w;
433 			else /* word_len <= 32 */
434 				((u32 *)xfer->rx_buf)[elements++] = w;
435 		} else {
436 			dev_err(&spi->dev, "DMA RX penultimate word empty");
437 			count -= (word_len <= 8)  ? 2 :
438 				(word_len <= 16) ? 4 :
439 				/* word_len <= 32 */ 8;
440 			omap2_mcspi_set_enable(spi, 1);
441 			return count;
442 		}
443 	}
444 	if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
445 				& OMAP2_MCSPI_CHSTAT_RXS)) {
446 		u32 w;
447 
448 		w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
449 		if (word_len <= 8)
450 			((u8 *)xfer->rx_buf)[elements] = w;
451 		else if (word_len <= 16)
452 			((u16 *)xfer->rx_buf)[elements] = w;
453 		else /* word_len <= 32 */
454 			((u32 *)xfer->rx_buf)[elements] = w;
455 	} else {
456 		dev_err(&spi->dev, "DMA RX last word empty");
457 		count -= (word_len <= 8)  ? 1 :
458 			 (word_len <= 16) ? 2 :
459 		       /* word_len <= 32 */ 4;
460 	}
461 	omap2_mcspi_set_enable(spi, 1);
462 	return count;
463 }
464 
465 static unsigned
466 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
467 {
468 	struct omap2_mcspi	*mcspi;
469 	struct omap2_mcspi_cs	*cs = spi->controller_state;
470 	struct omap2_mcspi_dma  *mcspi_dma;
471 	unsigned int		count;
472 	u32			l;
473 	u8			*rx;
474 	const u8		*tx;
475 	struct dma_slave_config	cfg;
476 	enum dma_slave_buswidth width;
477 	unsigned es;
478 	void __iomem		*chstat_reg;
479 
480 	mcspi = spi_master_get_devdata(spi->master);
481 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
482 	l = mcspi_cached_chconf0(spi);
483 
484 
485 	if (cs->word_len <= 8) {
486 		width = DMA_SLAVE_BUSWIDTH_1_BYTE;
487 		es = 1;
488 	} else if (cs->word_len <= 16) {
489 		width = DMA_SLAVE_BUSWIDTH_2_BYTES;
490 		es = 2;
491 	} else {
492 		width = DMA_SLAVE_BUSWIDTH_4_BYTES;
493 		es = 4;
494 	}
495 
496 	memset(&cfg, 0, sizeof(cfg));
497 	cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
498 	cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
499 	cfg.src_addr_width = width;
500 	cfg.dst_addr_width = width;
501 	cfg.src_maxburst = 1;
502 	cfg.dst_maxburst = 1;
503 
504 	rx = xfer->rx_buf;
505 	tx = xfer->tx_buf;
506 
507 	count = xfer->len;
508 
509 	if (tx != NULL)
510 		omap2_mcspi_tx_dma(spi, xfer, cfg);
511 
512 	if (rx != NULL)
513 		count = omap2_mcspi_rx_dma(spi, xfer, cfg, es);
514 
515 	if (tx != NULL) {
516 		chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
517 		wait_for_completion(&mcspi_dma->dma_tx_completion);
518 		dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
519 				 DMA_TO_DEVICE);
520 
521 		/* for TX_ONLY mode, be sure all words have shifted out */
522 		if (rx == NULL) {
523 			if (mcspi_wait_for_reg_bit(chstat_reg,
524 						OMAP2_MCSPI_CHSTAT_TXS) < 0)
525 				dev_err(&spi->dev, "TXS timed out\n");
526 			else if (mcspi_wait_for_reg_bit(chstat_reg,
527 						OMAP2_MCSPI_CHSTAT_EOT) < 0)
528 				dev_err(&spi->dev, "EOT timed out\n");
529 		}
530 	}
531 	return count;
532 }
533 
534 static unsigned
535 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
536 {
537 	struct omap2_mcspi	*mcspi;
538 	struct omap2_mcspi_cs	*cs = spi->controller_state;
539 	unsigned int		count, c;
540 	u32			l;
541 	void __iomem		*base = cs->base;
542 	void __iomem		*tx_reg;
543 	void __iomem		*rx_reg;
544 	void __iomem		*chstat_reg;
545 	int			word_len;
546 
547 	mcspi = spi_master_get_devdata(spi->master);
548 	count = xfer->len;
549 	c = count;
550 	word_len = cs->word_len;
551 
552 	l = mcspi_cached_chconf0(spi);
553 
554 	/* We store the pre-calculated register addresses on stack to speed
555 	 * up the transfer loop. */
556 	tx_reg		= base + OMAP2_MCSPI_TX0;
557 	rx_reg		= base + OMAP2_MCSPI_RX0;
558 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
559 
560 	if (c < (word_len>>3))
561 		return 0;
562 
563 	if (word_len <= 8) {
564 		u8		*rx;
565 		const u8	*tx;
566 
567 		rx = xfer->rx_buf;
568 		tx = xfer->tx_buf;
569 
570 		do {
571 			c -= 1;
572 			if (tx != NULL) {
573 				if (mcspi_wait_for_reg_bit(chstat_reg,
574 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
575 					dev_err(&spi->dev, "TXS timed out\n");
576 					goto out;
577 				}
578 				dev_vdbg(&spi->dev, "write-%d %02x\n",
579 						word_len, *tx);
580 				__raw_writel(*tx++, tx_reg);
581 			}
582 			if (rx != NULL) {
583 				if (mcspi_wait_for_reg_bit(chstat_reg,
584 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
585 					dev_err(&spi->dev, "RXS timed out\n");
586 					goto out;
587 				}
588 
589 				if (c == 1 && tx == NULL &&
590 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
591 					omap2_mcspi_set_enable(spi, 0);
592 					*rx++ = __raw_readl(rx_reg);
593 					dev_vdbg(&spi->dev, "read-%d %02x\n",
594 						    word_len, *(rx - 1));
595 					if (mcspi_wait_for_reg_bit(chstat_reg,
596 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
597 						dev_err(&spi->dev,
598 							"RXS timed out\n");
599 						goto out;
600 					}
601 					c = 0;
602 				} else if (c == 0 && tx == NULL) {
603 					omap2_mcspi_set_enable(spi, 0);
604 				}
605 
606 				*rx++ = __raw_readl(rx_reg);
607 				dev_vdbg(&spi->dev, "read-%d %02x\n",
608 						word_len, *(rx - 1));
609 			}
610 		} while (c);
611 	} else if (word_len <= 16) {
612 		u16		*rx;
613 		const u16	*tx;
614 
615 		rx = xfer->rx_buf;
616 		tx = xfer->tx_buf;
617 		do {
618 			c -= 2;
619 			if (tx != NULL) {
620 				if (mcspi_wait_for_reg_bit(chstat_reg,
621 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
622 					dev_err(&spi->dev, "TXS timed out\n");
623 					goto out;
624 				}
625 				dev_vdbg(&spi->dev, "write-%d %04x\n",
626 						word_len, *tx);
627 				__raw_writel(*tx++, tx_reg);
628 			}
629 			if (rx != NULL) {
630 				if (mcspi_wait_for_reg_bit(chstat_reg,
631 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
632 					dev_err(&spi->dev, "RXS timed out\n");
633 					goto out;
634 				}
635 
636 				if (c == 2 && tx == NULL &&
637 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
638 					omap2_mcspi_set_enable(spi, 0);
639 					*rx++ = __raw_readl(rx_reg);
640 					dev_vdbg(&spi->dev, "read-%d %04x\n",
641 						    word_len, *(rx - 1));
642 					if (mcspi_wait_for_reg_bit(chstat_reg,
643 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
644 						dev_err(&spi->dev,
645 							"RXS timed out\n");
646 						goto out;
647 					}
648 					c = 0;
649 				} else if (c == 0 && tx == NULL) {
650 					omap2_mcspi_set_enable(spi, 0);
651 				}
652 
653 				*rx++ = __raw_readl(rx_reg);
654 				dev_vdbg(&spi->dev, "read-%d %04x\n",
655 						word_len, *(rx - 1));
656 			}
657 		} while (c >= 2);
658 	} else if (word_len <= 32) {
659 		u32		*rx;
660 		const u32	*tx;
661 
662 		rx = xfer->rx_buf;
663 		tx = xfer->tx_buf;
664 		do {
665 			c -= 4;
666 			if (tx != NULL) {
667 				if (mcspi_wait_for_reg_bit(chstat_reg,
668 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
669 					dev_err(&spi->dev, "TXS timed out\n");
670 					goto out;
671 				}
672 				dev_vdbg(&spi->dev, "write-%d %08x\n",
673 						word_len, *tx);
674 				__raw_writel(*tx++, tx_reg);
675 			}
676 			if (rx != NULL) {
677 				if (mcspi_wait_for_reg_bit(chstat_reg,
678 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
679 					dev_err(&spi->dev, "RXS timed out\n");
680 					goto out;
681 				}
682 
683 				if (c == 4 && tx == NULL &&
684 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
685 					omap2_mcspi_set_enable(spi, 0);
686 					*rx++ = __raw_readl(rx_reg);
687 					dev_vdbg(&spi->dev, "read-%d %08x\n",
688 						    word_len, *(rx - 1));
689 					if (mcspi_wait_for_reg_bit(chstat_reg,
690 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
691 						dev_err(&spi->dev,
692 							"RXS timed out\n");
693 						goto out;
694 					}
695 					c = 0;
696 				} else if (c == 0 && tx == NULL) {
697 					omap2_mcspi_set_enable(spi, 0);
698 				}
699 
700 				*rx++ = __raw_readl(rx_reg);
701 				dev_vdbg(&spi->dev, "read-%d %08x\n",
702 						word_len, *(rx - 1));
703 			}
704 		} while (c >= 4);
705 	}
706 
707 	/* for TX_ONLY mode, be sure all words have shifted out */
708 	if (xfer->rx_buf == NULL) {
709 		if (mcspi_wait_for_reg_bit(chstat_reg,
710 				OMAP2_MCSPI_CHSTAT_TXS) < 0) {
711 			dev_err(&spi->dev, "TXS timed out\n");
712 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
713 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
714 			dev_err(&spi->dev, "EOT timed out\n");
715 
716 		/* disable chan to purge rx datas received in TX_ONLY transfer,
717 		 * otherwise these rx datas will affect the direct following
718 		 * RX_ONLY transfer.
719 		 */
720 		omap2_mcspi_set_enable(spi, 0);
721 	}
722 out:
723 	omap2_mcspi_set_enable(spi, 1);
724 	return count - c;
725 }
726 
727 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
728 {
729 	u32 div;
730 
731 	for (div = 0; div < 15; div++)
732 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
733 			return div;
734 
735 	return 15;
736 }
737 
738 /* called only when no transfer is active to this device */
739 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
740 		struct spi_transfer *t)
741 {
742 	struct omap2_mcspi_cs *cs = spi->controller_state;
743 	struct omap2_mcspi *mcspi;
744 	struct spi_master *spi_cntrl;
745 	u32 l = 0, div = 0;
746 	u8 word_len = spi->bits_per_word;
747 	u32 speed_hz = spi->max_speed_hz;
748 
749 	mcspi = spi_master_get_devdata(spi->master);
750 	spi_cntrl = mcspi->master;
751 
752 	if (t != NULL && t->bits_per_word)
753 		word_len = t->bits_per_word;
754 
755 	cs->word_len = word_len;
756 
757 	if (t && t->speed_hz)
758 		speed_hz = t->speed_hz;
759 
760 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
761 	div = omap2_mcspi_calc_divisor(speed_hz);
762 
763 	l = mcspi_cached_chconf0(spi);
764 
765 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
766 	 * REVISIT: this controller could support SPI_3WIRE mode.
767 	 */
768 	if (mcspi->pin_dir == MCSPI_PINDIR_D0_IN_D1_OUT) {
769 		l &= ~OMAP2_MCSPI_CHCONF_IS;
770 		l &= ~OMAP2_MCSPI_CHCONF_DPE1;
771 		l |= OMAP2_MCSPI_CHCONF_DPE0;
772 	} else {
773 		l |= OMAP2_MCSPI_CHCONF_IS;
774 		l |= OMAP2_MCSPI_CHCONF_DPE1;
775 		l &= ~OMAP2_MCSPI_CHCONF_DPE0;
776 	}
777 
778 	/* wordlength */
779 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
780 	l |= (word_len - 1) << 7;
781 
782 	/* set chipselect polarity; manage with FORCE */
783 	if (!(spi->mode & SPI_CS_HIGH))
784 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
785 	else
786 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
787 
788 	/* set clock divisor */
789 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
790 	l |= div << 2;
791 
792 	/* set SPI mode 0..3 */
793 	if (spi->mode & SPI_CPOL)
794 		l |= OMAP2_MCSPI_CHCONF_POL;
795 	else
796 		l &= ~OMAP2_MCSPI_CHCONF_POL;
797 	if (spi->mode & SPI_CPHA)
798 		l |= OMAP2_MCSPI_CHCONF_PHA;
799 	else
800 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
801 
802 	mcspi_write_chconf0(spi, l);
803 
804 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
805 			OMAP2_MCSPI_MAX_FREQ >> div,
806 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
807 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
808 
809 	return 0;
810 }
811 
812 /*
813  * Note that we currently allow DMA only if we get a channel
814  * for both rx and tx. Otherwise we'll do PIO for both rx and tx.
815  */
816 static int omap2_mcspi_request_dma(struct spi_device *spi)
817 {
818 	struct spi_master	*master = spi->master;
819 	struct omap2_mcspi	*mcspi;
820 	struct omap2_mcspi_dma	*mcspi_dma;
821 	dma_cap_mask_t mask;
822 	unsigned sig;
823 
824 	mcspi = spi_master_get_devdata(master);
825 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
826 
827 	init_completion(&mcspi_dma->dma_rx_completion);
828 	init_completion(&mcspi_dma->dma_tx_completion);
829 
830 	dma_cap_zero(mask);
831 	dma_cap_set(DMA_SLAVE, mask);
832 	sig = mcspi_dma->dma_rx_sync_dev;
833 	mcspi_dma->dma_rx = dma_request_channel(mask, omap_dma_filter_fn, &sig);
834 	if (!mcspi_dma->dma_rx)
835 		goto no_dma;
836 
837 	sig = mcspi_dma->dma_tx_sync_dev;
838 	mcspi_dma->dma_tx = dma_request_channel(mask, omap_dma_filter_fn, &sig);
839 	if (!mcspi_dma->dma_tx) {
840 		dma_release_channel(mcspi_dma->dma_rx);
841 		mcspi_dma->dma_rx = NULL;
842 		goto no_dma;
843 	}
844 
845 	return 0;
846 
847 no_dma:
848 	dev_warn(&spi->dev, "not using DMA for McSPI\n");
849 	return -EAGAIN;
850 }
851 
852 static int omap2_mcspi_setup(struct spi_device *spi)
853 {
854 	int			ret;
855 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(spi->master);
856 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
857 	struct omap2_mcspi_dma	*mcspi_dma;
858 	struct omap2_mcspi_cs	*cs = spi->controller_state;
859 
860 	if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
861 		dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
862 			spi->bits_per_word);
863 		return -EINVAL;
864 	}
865 
866 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
867 
868 	if (!cs) {
869 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
870 		if (!cs)
871 			return -ENOMEM;
872 		cs->base = mcspi->base + spi->chip_select * 0x14;
873 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
874 		cs->chconf0 = 0;
875 		spi->controller_state = cs;
876 		/* Link this to context save list */
877 		list_add_tail(&cs->node, &ctx->cs);
878 	}
879 
880 	if (!mcspi_dma->dma_rx || !mcspi_dma->dma_tx) {
881 		ret = omap2_mcspi_request_dma(spi);
882 		if (ret < 0 && ret != -EAGAIN)
883 			return ret;
884 	}
885 
886 	ret = pm_runtime_get_sync(mcspi->dev);
887 	if (ret < 0)
888 		return ret;
889 
890 	ret = omap2_mcspi_setup_transfer(spi, NULL);
891 	pm_runtime_mark_last_busy(mcspi->dev);
892 	pm_runtime_put_autosuspend(mcspi->dev);
893 
894 	return ret;
895 }
896 
897 static void omap2_mcspi_cleanup(struct spi_device *spi)
898 {
899 	struct omap2_mcspi	*mcspi;
900 	struct omap2_mcspi_dma	*mcspi_dma;
901 	struct omap2_mcspi_cs	*cs;
902 
903 	mcspi = spi_master_get_devdata(spi->master);
904 
905 	if (spi->controller_state) {
906 		/* Unlink controller state from context save list */
907 		cs = spi->controller_state;
908 		list_del(&cs->node);
909 
910 		kfree(cs);
911 	}
912 
913 	if (spi->chip_select < spi->master->num_chipselect) {
914 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
915 
916 		if (mcspi_dma->dma_rx) {
917 			dma_release_channel(mcspi_dma->dma_rx);
918 			mcspi_dma->dma_rx = NULL;
919 		}
920 		if (mcspi_dma->dma_tx) {
921 			dma_release_channel(mcspi_dma->dma_tx);
922 			mcspi_dma->dma_tx = NULL;
923 		}
924 	}
925 }
926 
927 static void omap2_mcspi_work(struct omap2_mcspi *mcspi, struct spi_message *m)
928 {
929 
930 	/* We only enable one channel at a time -- the one whose message is
931 	 * -- although this controller would gladly
932 	 * arbitrate among multiple channels.  This corresponds to "single
933 	 * channel" master mode.  As a side effect, we need to manage the
934 	 * chipselect with the FORCE bit ... CS != channel enable.
935 	 */
936 
937 	struct spi_device		*spi;
938 	struct spi_transfer		*t = NULL;
939 	struct spi_master		*master;
940 	struct omap2_mcspi_dma		*mcspi_dma;
941 	int				cs_active = 0;
942 	struct omap2_mcspi_cs		*cs;
943 	struct omap2_mcspi_device_config *cd;
944 	int				par_override = 0;
945 	int				status = 0;
946 	u32				chconf;
947 
948 	spi = m->spi;
949 	master = spi->master;
950 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
951 	cs = spi->controller_state;
952 	cd = spi->controller_data;
953 
954 	omap2_mcspi_set_enable(spi, 1);
955 	list_for_each_entry(t, &m->transfers, transfer_list) {
956 		if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
957 			status = -EINVAL;
958 			break;
959 		}
960 		if (par_override || t->speed_hz || t->bits_per_word) {
961 			par_override = 1;
962 			status = omap2_mcspi_setup_transfer(spi, t);
963 			if (status < 0)
964 				break;
965 			if (!t->speed_hz && !t->bits_per_word)
966 				par_override = 0;
967 		}
968 		if (cd && cd->cs_per_word) {
969 			chconf = mcspi->ctx.modulctrl;
970 			chconf &= ~OMAP2_MCSPI_MODULCTRL_SINGLE;
971 			mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
972 			mcspi->ctx.modulctrl =
973 				mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
974 		}
975 
976 
977 		if (!cs_active) {
978 			omap2_mcspi_force_cs(spi, 1);
979 			cs_active = 1;
980 		}
981 
982 		chconf = mcspi_cached_chconf0(spi);
983 		chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
984 		chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
985 
986 		if (t->tx_buf == NULL)
987 			chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
988 		else if (t->rx_buf == NULL)
989 			chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
990 
991 		if (cd && cd->turbo_mode && t->tx_buf == NULL) {
992 			/* Turbo mode is for more than one word */
993 			if (t->len > ((cs->word_len + 7) >> 3))
994 				chconf |= OMAP2_MCSPI_CHCONF_TURBO;
995 		}
996 
997 		mcspi_write_chconf0(spi, chconf);
998 
999 		if (t->len) {
1000 			unsigned	count;
1001 
1002 			/* RX_ONLY mode needs dummy data in TX reg */
1003 			if (t->tx_buf == NULL)
1004 				__raw_writel(0, cs->base
1005 						+ OMAP2_MCSPI_TX0);
1006 
1007 			if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
1008 			    (m->is_dma_mapped || t->len >= DMA_MIN_BYTES))
1009 				count = omap2_mcspi_txrx_dma(spi, t);
1010 			else
1011 				count = omap2_mcspi_txrx_pio(spi, t);
1012 			m->actual_length += count;
1013 
1014 			if (count != t->len) {
1015 				status = -EIO;
1016 				break;
1017 			}
1018 		}
1019 
1020 		if (t->delay_usecs)
1021 			udelay(t->delay_usecs);
1022 
1023 		/* ignore the "leave it on after last xfer" hint */
1024 		if (t->cs_change) {
1025 			omap2_mcspi_force_cs(spi, 0);
1026 			cs_active = 0;
1027 		}
1028 	}
1029 	/* Restore defaults if they were overriden */
1030 	if (par_override) {
1031 		par_override = 0;
1032 		status = omap2_mcspi_setup_transfer(spi, NULL);
1033 	}
1034 
1035 	if (cs_active)
1036 		omap2_mcspi_force_cs(spi, 0);
1037 
1038 	if (cd && cd->cs_per_word) {
1039 		chconf = mcspi->ctx.modulctrl;
1040 		chconf |= OMAP2_MCSPI_MODULCTRL_SINGLE;
1041 		mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, chconf);
1042 		mcspi->ctx.modulctrl =
1043 			mcspi_read_cs_reg(spi, OMAP2_MCSPI_MODULCTRL);
1044 	}
1045 
1046 	omap2_mcspi_set_enable(spi, 0);
1047 
1048 	m->status = status;
1049 
1050 }
1051 
1052 static int omap2_mcspi_transfer_one_message(struct spi_master *master,
1053 		struct spi_message *m)
1054 {
1055 	struct spi_device	*spi;
1056 	struct omap2_mcspi	*mcspi;
1057 	struct omap2_mcspi_dma	*mcspi_dma;
1058 	struct spi_transfer	*t;
1059 
1060 	spi = m->spi;
1061 	mcspi = spi_master_get_devdata(master);
1062 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
1063 	m->actual_length = 0;
1064 	m->status = 0;
1065 
1066 	/* reject invalid messages and transfers */
1067 	if (list_empty(&m->transfers))
1068 		return -EINVAL;
1069 	list_for_each_entry(t, &m->transfers, transfer_list) {
1070 		const void	*tx_buf = t->tx_buf;
1071 		void		*rx_buf = t->rx_buf;
1072 		unsigned	len = t->len;
1073 
1074 		if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
1075 				|| (len && !(rx_buf || tx_buf))
1076 				|| (t->bits_per_word &&
1077 					(  t->bits_per_word < 4
1078 					   || t->bits_per_word > 32))) {
1079 			dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1080 					t->speed_hz,
1081 					len,
1082 					tx_buf ? "tx" : "",
1083 					rx_buf ? "rx" : "",
1084 					t->bits_per_word);
1085 			return -EINVAL;
1086 		}
1087 		if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
1088 			dev_dbg(mcspi->dev, "speed_hz %d below minimum %d Hz\n",
1089 					t->speed_hz,
1090 					OMAP2_MCSPI_MAX_FREQ >> 15);
1091 			return -EINVAL;
1092 		}
1093 
1094 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1095 			continue;
1096 
1097 		if (mcspi_dma->dma_tx && tx_buf != NULL) {
1098 			t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
1099 					len, DMA_TO_DEVICE);
1100 			if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
1101 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1102 						'T', len);
1103 				return -EINVAL;
1104 			}
1105 		}
1106 		if (mcspi_dma->dma_rx && rx_buf != NULL) {
1107 			t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
1108 					DMA_FROM_DEVICE);
1109 			if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
1110 				dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
1111 						'R', len);
1112 				if (tx_buf != NULL)
1113 					dma_unmap_single(mcspi->dev, t->tx_dma,
1114 							len, DMA_TO_DEVICE);
1115 				return -EINVAL;
1116 			}
1117 		}
1118 	}
1119 
1120 	omap2_mcspi_work(mcspi, m);
1121 	spi_finalize_current_message(master);
1122 	return 0;
1123 }
1124 
1125 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1126 {
1127 	struct spi_master	*master = mcspi->master;
1128 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1129 	int			ret = 0;
1130 
1131 	ret = pm_runtime_get_sync(mcspi->dev);
1132 	if (ret < 0)
1133 		return ret;
1134 
1135 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE,
1136 			OMAP2_MCSPI_WAKEUPENABLE_WKEN);
1137 	ctx->wakeupenable = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1138 
1139 	omap2_mcspi_set_master_mode(master);
1140 	pm_runtime_mark_last_busy(mcspi->dev);
1141 	pm_runtime_put_autosuspend(mcspi->dev);
1142 	return 0;
1143 }
1144 
1145 static int omap_mcspi_runtime_resume(struct device *dev)
1146 {
1147 	struct omap2_mcspi	*mcspi;
1148 	struct spi_master	*master;
1149 
1150 	master = dev_get_drvdata(dev);
1151 	mcspi = spi_master_get_devdata(master);
1152 	omap2_mcspi_restore_ctx(mcspi);
1153 
1154 	return 0;
1155 }
1156 
1157 static struct omap2_mcspi_platform_config omap2_pdata = {
1158 	.regs_offset = 0,
1159 };
1160 
1161 static struct omap2_mcspi_platform_config omap4_pdata = {
1162 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1163 };
1164 
1165 static const struct of_device_id omap_mcspi_of_match[] = {
1166 	{
1167 		.compatible = "ti,omap2-mcspi",
1168 		.data = &omap2_pdata,
1169 	},
1170 	{
1171 		.compatible = "ti,omap4-mcspi",
1172 		.data = &omap4_pdata,
1173 	},
1174 	{ },
1175 };
1176 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1177 
1178 static int omap2_mcspi_probe(struct platform_device *pdev)
1179 {
1180 	struct spi_master	*master;
1181 	const struct omap2_mcspi_platform_config *pdata;
1182 	struct omap2_mcspi	*mcspi;
1183 	struct resource		*r;
1184 	int			status = 0, i;
1185 	u32			regs_offset = 0;
1186 	static int		bus_num = 1;
1187 	struct device_node	*node = pdev->dev.of_node;
1188 	const struct of_device_id *match;
1189 	struct pinctrl *pinctrl;
1190 
1191 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1192 	if (master == NULL) {
1193 		dev_dbg(&pdev->dev, "master allocation failed\n");
1194 		return -ENOMEM;
1195 	}
1196 
1197 	/* the spi->mode bits understood by this driver: */
1198 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1199 
1200 	master->setup = omap2_mcspi_setup;
1201 	master->prepare_transfer_hardware = omap2_prepare_transfer;
1202 	master->unprepare_transfer_hardware = omap2_unprepare_transfer;
1203 	master->transfer_one_message = omap2_mcspi_transfer_one_message;
1204 	master->cleanup = omap2_mcspi_cleanup;
1205 	master->dev.of_node = node;
1206 
1207 	dev_set_drvdata(&pdev->dev, master);
1208 
1209 	mcspi = spi_master_get_devdata(master);
1210 	mcspi->master = master;
1211 
1212 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1213 	if (match) {
1214 		u32 num_cs = 1; /* default number of chipselect */
1215 		pdata = match->data;
1216 
1217 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1218 		master->num_chipselect = num_cs;
1219 		master->bus_num = bus_num++;
1220 		if (of_get_property(node, "ti,pindir-d0-out-d1-in", NULL))
1221 			mcspi->pin_dir = MCSPI_PINDIR_D0_OUT_D1_IN;
1222 	} else {
1223 		pdata = pdev->dev.platform_data;
1224 		master->num_chipselect = pdata->num_cs;
1225 		if (pdev->id != -1)
1226 			master->bus_num = pdev->id;
1227 		mcspi->pin_dir = pdata->pin_dir;
1228 	}
1229 	regs_offset = pdata->regs_offset;
1230 
1231 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1232 	if (r == NULL) {
1233 		status = -ENODEV;
1234 		goto free_master;
1235 	}
1236 
1237 	r->start += regs_offset;
1238 	r->end += regs_offset;
1239 	mcspi->phys = r->start;
1240 
1241 	mcspi->base = devm_ioremap_resource(&pdev->dev, r);
1242 	if (IS_ERR(mcspi->base)) {
1243 		status = PTR_ERR(mcspi->base);
1244 		goto free_master;
1245 	}
1246 
1247 	mcspi->dev = &pdev->dev;
1248 
1249 	INIT_LIST_HEAD(&mcspi->ctx.cs);
1250 
1251 	mcspi->dma_channels = kcalloc(master->num_chipselect,
1252 			sizeof(struct omap2_mcspi_dma),
1253 			GFP_KERNEL);
1254 
1255 	if (mcspi->dma_channels == NULL)
1256 		goto free_master;
1257 
1258 	for (i = 0; i < master->num_chipselect; i++) {
1259 		char dma_ch_name[14];
1260 		struct resource *dma_res;
1261 
1262 		sprintf(dma_ch_name, "rx%d", i);
1263 		dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA,
1264 				dma_ch_name);
1265 		if (!dma_res) {
1266 			dev_dbg(&pdev->dev, "cannot get DMA RX channel\n");
1267 			status = -ENODEV;
1268 			break;
1269 		}
1270 
1271 		mcspi->dma_channels[i].dma_rx_sync_dev = dma_res->start;
1272 		sprintf(dma_ch_name, "tx%d", i);
1273 		dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA,
1274 				dma_ch_name);
1275 		if (!dma_res) {
1276 			dev_dbg(&pdev->dev, "cannot get DMA TX channel\n");
1277 			status = -ENODEV;
1278 			break;
1279 		}
1280 
1281 		mcspi->dma_channels[i].dma_tx_sync_dev = dma_res->start;
1282 	}
1283 
1284 	if (status < 0)
1285 		goto dma_chnl_free;
1286 
1287 	pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
1288 	if (IS_ERR(pinctrl))
1289 		dev_warn(&pdev->dev,
1290 				"pins are not configured from the driver\n");
1291 
1292 	pm_runtime_use_autosuspend(&pdev->dev);
1293 	pm_runtime_set_autosuspend_delay(&pdev->dev, SPI_AUTOSUSPEND_TIMEOUT);
1294 	pm_runtime_enable(&pdev->dev);
1295 
1296 	status = omap2_mcspi_master_setup(mcspi);
1297 	if (status < 0)
1298 		goto disable_pm;
1299 
1300 	status = spi_register_master(master);
1301 	if (status < 0)
1302 		goto disable_pm;
1303 
1304 	return status;
1305 
1306 disable_pm:
1307 	pm_runtime_disable(&pdev->dev);
1308 dma_chnl_free:
1309 	kfree(mcspi->dma_channels);
1310 free_master:
1311 	spi_master_put(master);
1312 	return status;
1313 }
1314 
1315 static int omap2_mcspi_remove(struct platform_device *pdev)
1316 {
1317 	struct spi_master	*master;
1318 	struct omap2_mcspi	*mcspi;
1319 	struct omap2_mcspi_dma	*dma_channels;
1320 
1321 	master = dev_get_drvdata(&pdev->dev);
1322 	mcspi = spi_master_get_devdata(master);
1323 	dma_channels = mcspi->dma_channels;
1324 
1325 	pm_runtime_put_sync(mcspi->dev);
1326 	pm_runtime_disable(&pdev->dev);
1327 
1328 	spi_unregister_master(master);
1329 	kfree(dma_channels);
1330 
1331 	return 0;
1332 }
1333 
1334 /* work with hotplug and coldplug */
1335 MODULE_ALIAS("platform:omap2_mcspi");
1336 
1337 #ifdef	CONFIG_SUSPEND
1338 /*
1339  * When SPI wake up from off-mode, CS is in activate state. If it was in
1340  * unactive state when driver was suspend, then force it to unactive state at
1341  * wake up.
1342  */
1343 static int omap2_mcspi_resume(struct device *dev)
1344 {
1345 	struct spi_master	*master = dev_get_drvdata(dev);
1346 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1347 	struct omap2_mcspi_regs	*ctx = &mcspi->ctx;
1348 	struct omap2_mcspi_cs	*cs;
1349 
1350 	pm_runtime_get_sync(mcspi->dev);
1351 	list_for_each_entry(cs, &ctx->cs, node) {
1352 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1353 			/*
1354 			 * We need to toggle CS state for OMAP take this
1355 			 * change in account.
1356 			 */
1357 			cs->chconf0 |= OMAP2_MCSPI_CHCONF_FORCE;
1358 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1359 			cs->chconf0 &= ~OMAP2_MCSPI_CHCONF_FORCE;
1360 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1361 		}
1362 	}
1363 	pm_runtime_mark_last_busy(mcspi->dev);
1364 	pm_runtime_put_autosuspend(mcspi->dev);
1365 	return 0;
1366 }
1367 #else
1368 #define	omap2_mcspi_resume	NULL
1369 #endif
1370 
1371 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1372 	.resume = omap2_mcspi_resume,
1373 	.runtime_resume	= omap_mcspi_runtime_resume,
1374 };
1375 
1376 static struct platform_driver omap2_mcspi_driver = {
1377 	.driver = {
1378 		.name =		"omap2_mcspi",
1379 		.owner =	THIS_MODULE,
1380 		.pm =		&omap2_mcspi_pm_ops,
1381 		.of_match_table = omap_mcspi_of_match,
1382 	},
1383 	.probe =	omap2_mcspi_probe,
1384 	.remove =	omap2_mcspi_remove,
1385 };
1386 
1387 module_platform_driver(omap2_mcspi_driver);
1388 MODULE_LICENSE("GPL");
1389