xref: /openbmc/linux/drivers/spi/spi-omap2-mcspi.c (revision d41ced01f21ddd2c3a01531bb9edf6c41064e9fc)
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/platform_device.h>
32 #include <linux/err.h>
33 #include <linux/clk.h>
34 #include <linux/io.h>
35 #include <linux/slab.h>
36 #include <linux/pm_runtime.h>
37 #include <linux/of.h>
38 #include <linux/of_device.h>
39 
40 #include <linux/spi/spi.h>
41 
42 #include <plat/dma.h>
43 #include <plat/clock.h>
44 #include <plat/mcspi.h>
45 
46 #define OMAP2_MCSPI_MAX_FREQ		48000000
47 
48 /* OMAP2 has 3 SPI controllers, while OMAP3 has 4 */
49 #define OMAP2_MCSPI_MAX_CTRL 		4
50 
51 #define OMAP2_MCSPI_REVISION		0x00
52 #define OMAP2_MCSPI_SYSSTATUS		0x14
53 #define OMAP2_MCSPI_IRQSTATUS		0x18
54 #define OMAP2_MCSPI_IRQENABLE		0x1c
55 #define OMAP2_MCSPI_WAKEUPENABLE	0x20
56 #define OMAP2_MCSPI_SYST		0x24
57 #define OMAP2_MCSPI_MODULCTRL		0x28
58 
59 /* per-channel banks, 0x14 bytes each, first is: */
60 #define OMAP2_MCSPI_CHCONF0		0x2c
61 #define OMAP2_MCSPI_CHSTAT0		0x30
62 #define OMAP2_MCSPI_CHCTRL0		0x34
63 #define OMAP2_MCSPI_TX0			0x38
64 #define OMAP2_MCSPI_RX0			0x3c
65 
66 /* per-register bitmasks: */
67 
68 #define OMAP2_MCSPI_MODULCTRL_SINGLE	BIT(0)
69 #define OMAP2_MCSPI_MODULCTRL_MS	BIT(2)
70 #define OMAP2_MCSPI_MODULCTRL_STEST	BIT(3)
71 
72 #define OMAP2_MCSPI_CHCONF_PHA		BIT(0)
73 #define OMAP2_MCSPI_CHCONF_POL		BIT(1)
74 #define OMAP2_MCSPI_CHCONF_CLKD_MASK	(0x0f << 2)
75 #define OMAP2_MCSPI_CHCONF_EPOL		BIT(6)
76 #define OMAP2_MCSPI_CHCONF_WL_MASK	(0x1f << 7)
77 #define OMAP2_MCSPI_CHCONF_TRM_RX_ONLY	BIT(12)
78 #define OMAP2_MCSPI_CHCONF_TRM_TX_ONLY	BIT(13)
79 #define OMAP2_MCSPI_CHCONF_TRM_MASK	(0x03 << 12)
80 #define OMAP2_MCSPI_CHCONF_DMAW		BIT(14)
81 #define OMAP2_MCSPI_CHCONF_DMAR		BIT(15)
82 #define OMAP2_MCSPI_CHCONF_DPE0		BIT(16)
83 #define OMAP2_MCSPI_CHCONF_DPE1		BIT(17)
84 #define OMAP2_MCSPI_CHCONF_IS		BIT(18)
85 #define OMAP2_MCSPI_CHCONF_TURBO	BIT(19)
86 #define OMAP2_MCSPI_CHCONF_FORCE	BIT(20)
87 
88 #define OMAP2_MCSPI_CHSTAT_RXS		BIT(0)
89 #define OMAP2_MCSPI_CHSTAT_TXS		BIT(1)
90 #define OMAP2_MCSPI_CHSTAT_EOT		BIT(2)
91 
92 #define OMAP2_MCSPI_CHCTRL_EN		BIT(0)
93 
94 #define OMAP2_MCSPI_WAKEUPENABLE_WKEN	BIT(0)
95 
96 /* We have 2 DMA channels per CS, one for RX and one for TX */
97 struct omap2_mcspi_dma {
98 	int dma_tx_channel;
99 	int dma_rx_channel;
100 
101 	int dma_tx_sync_dev;
102 	int dma_rx_sync_dev;
103 
104 	struct completion dma_tx_completion;
105 	struct completion dma_rx_completion;
106 };
107 
108 /* use PIO for small transfers, avoiding DMA setup/teardown overhead and
109  * cache operations; better heuristics consider wordsize and bitrate.
110  */
111 #define DMA_MIN_BYTES			160
112 
113 
114 struct omap2_mcspi {
115 	struct work_struct	work;
116 	/* lock protects queue and registers */
117 	spinlock_t		lock;
118 	struct list_head	msg_queue;
119 	struct spi_master	*master;
120 	/* Virtual base address of the controller */
121 	void __iomem		*base;
122 	unsigned long		phys;
123 	/* SPI1 has 4 channels, while SPI2 has 2 */
124 	struct omap2_mcspi_dma	*dma_channels;
125 	struct  device		*dev;
126 	struct workqueue_struct *wq;
127 };
128 
129 struct omap2_mcspi_cs {
130 	void __iomem		*base;
131 	unsigned long		phys;
132 	int			word_len;
133 	struct list_head	node;
134 	/* Context save and restore shadow register */
135 	u32			chconf0;
136 };
137 
138 /* used for context save and restore, structure members to be updated whenever
139  * corresponding registers are modified.
140  */
141 struct omap2_mcspi_regs {
142 	u32 modulctrl;
143 	u32 wakeupenable;
144 	struct list_head cs;
145 };
146 
147 static struct omap2_mcspi_regs omap2_mcspi_ctx[OMAP2_MCSPI_MAX_CTRL];
148 
149 #define MOD_REG_BIT(val, mask, set) do { \
150 	if (set) \
151 		val |= mask; \
152 	else \
153 		val &= ~mask; \
154 } while (0)
155 
156 static inline void mcspi_write_reg(struct spi_master *master,
157 		int idx, u32 val)
158 {
159 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
160 
161 	__raw_writel(val, mcspi->base + idx);
162 }
163 
164 static inline u32 mcspi_read_reg(struct spi_master *master, int idx)
165 {
166 	struct omap2_mcspi *mcspi = spi_master_get_devdata(master);
167 
168 	return __raw_readl(mcspi->base + idx);
169 }
170 
171 static inline void mcspi_write_cs_reg(const struct spi_device *spi,
172 		int idx, u32 val)
173 {
174 	struct omap2_mcspi_cs	*cs = spi->controller_state;
175 
176 	__raw_writel(val, cs->base +  idx);
177 }
178 
179 static inline u32 mcspi_read_cs_reg(const struct spi_device *spi, int idx)
180 {
181 	struct omap2_mcspi_cs	*cs = spi->controller_state;
182 
183 	return __raw_readl(cs->base + idx);
184 }
185 
186 static inline u32 mcspi_cached_chconf0(const struct spi_device *spi)
187 {
188 	struct omap2_mcspi_cs *cs = spi->controller_state;
189 
190 	return cs->chconf0;
191 }
192 
193 static inline void mcspi_write_chconf0(const struct spi_device *spi, u32 val)
194 {
195 	struct omap2_mcspi_cs *cs = spi->controller_state;
196 
197 	cs->chconf0 = val;
198 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCONF0, val);
199 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCONF0);
200 }
201 
202 static void omap2_mcspi_set_dma_req(const struct spi_device *spi,
203 		int is_read, int enable)
204 {
205 	u32 l, rw;
206 
207 	l = mcspi_cached_chconf0(spi);
208 
209 	if (is_read) /* 1 is read, 0 write */
210 		rw = OMAP2_MCSPI_CHCONF_DMAR;
211 	else
212 		rw = OMAP2_MCSPI_CHCONF_DMAW;
213 
214 	MOD_REG_BIT(l, rw, enable);
215 	mcspi_write_chconf0(spi, l);
216 }
217 
218 static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable)
219 {
220 	u32 l;
221 
222 	l = enable ? OMAP2_MCSPI_CHCTRL_EN : 0;
223 	mcspi_write_cs_reg(spi, OMAP2_MCSPI_CHCTRL0, l);
224 	/* Flash post-writes */
225 	mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHCTRL0);
226 }
227 
228 static void omap2_mcspi_force_cs(struct spi_device *spi, int cs_active)
229 {
230 	u32 l;
231 
232 	l = mcspi_cached_chconf0(spi);
233 	MOD_REG_BIT(l, OMAP2_MCSPI_CHCONF_FORCE, cs_active);
234 	mcspi_write_chconf0(spi, l);
235 }
236 
237 static void omap2_mcspi_set_master_mode(struct spi_master *master)
238 {
239 	u32 l;
240 
241 	/* setup when switching from (reset default) slave mode
242 	 * to single-channel master mode
243 	 */
244 	l = mcspi_read_reg(master, OMAP2_MCSPI_MODULCTRL);
245 	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_STEST, 0);
246 	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_MS, 0);
247 	MOD_REG_BIT(l, OMAP2_MCSPI_MODULCTRL_SINGLE, 1);
248 	mcspi_write_reg(master, OMAP2_MCSPI_MODULCTRL, l);
249 
250 	omap2_mcspi_ctx[master->bus_num - 1].modulctrl = l;
251 }
252 
253 static void omap2_mcspi_restore_ctx(struct omap2_mcspi *mcspi)
254 {
255 	struct spi_master *spi_cntrl;
256 	struct omap2_mcspi_cs *cs;
257 	spi_cntrl = mcspi->master;
258 
259 	/* McSPI: context restore */
260 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_MODULCTRL,
261 			omap2_mcspi_ctx[spi_cntrl->bus_num - 1].modulctrl);
262 
263 	mcspi_write_reg(spi_cntrl, OMAP2_MCSPI_WAKEUPENABLE,
264 			omap2_mcspi_ctx[spi_cntrl->bus_num - 1].wakeupenable);
265 
266 	list_for_each_entry(cs, &omap2_mcspi_ctx[spi_cntrl->bus_num - 1].cs,
267 			node)
268 		__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
269 }
270 static void omap2_mcspi_disable_clocks(struct omap2_mcspi *mcspi)
271 {
272 	pm_runtime_put_sync(mcspi->dev);
273 }
274 
275 static int omap2_mcspi_enable_clocks(struct omap2_mcspi *mcspi)
276 {
277 	return pm_runtime_get_sync(mcspi->dev);
278 }
279 
280 static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
281 {
282 	unsigned long timeout;
283 
284 	timeout = jiffies + msecs_to_jiffies(1000);
285 	while (!(__raw_readl(reg) & bit)) {
286 		if (time_after(jiffies, timeout))
287 			return -1;
288 		cpu_relax();
289 	}
290 	return 0;
291 }
292 
293 static unsigned
294 omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
295 {
296 	struct omap2_mcspi	*mcspi;
297 	struct omap2_mcspi_cs	*cs = spi->controller_state;
298 	struct omap2_mcspi_dma  *mcspi_dma;
299 	unsigned int		count, c;
300 	unsigned long		base, tx_reg, rx_reg;
301 	int			word_len, data_type, element_count;
302 	int			elements = 0;
303 	u32			l;
304 	u8			* rx;
305 	const u8		* tx;
306 	void __iomem		*chstat_reg;
307 
308 	mcspi = spi_master_get_devdata(spi->master);
309 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
310 	l = mcspi_cached_chconf0(spi);
311 
312 	chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;
313 
314 	count = xfer->len;
315 	c = count;
316 	word_len = cs->word_len;
317 
318 	base = cs->phys;
319 	tx_reg = base + OMAP2_MCSPI_TX0;
320 	rx_reg = base + OMAP2_MCSPI_RX0;
321 	rx = xfer->rx_buf;
322 	tx = xfer->tx_buf;
323 
324 	if (word_len <= 8) {
325 		data_type = OMAP_DMA_DATA_TYPE_S8;
326 		element_count = count;
327 	} else if (word_len <= 16) {
328 		data_type = OMAP_DMA_DATA_TYPE_S16;
329 		element_count = count >> 1;
330 	} else /* word_len <= 32 */ {
331 		data_type = OMAP_DMA_DATA_TYPE_S32;
332 		element_count = count >> 2;
333 	}
334 
335 	if (tx != NULL) {
336 		omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
337 				data_type, element_count, 1,
338 				OMAP_DMA_SYNC_ELEMENT,
339 				mcspi_dma->dma_tx_sync_dev, 0);
340 
341 		omap_set_dma_dest_params(mcspi_dma->dma_tx_channel, 0,
342 				OMAP_DMA_AMODE_CONSTANT,
343 				tx_reg, 0, 0);
344 
345 		omap_set_dma_src_params(mcspi_dma->dma_tx_channel, 0,
346 				OMAP_DMA_AMODE_POST_INC,
347 				xfer->tx_dma, 0, 0);
348 	}
349 
350 	if (rx != NULL) {
351 		elements = element_count - 1;
352 		if (l & OMAP2_MCSPI_CHCONF_TURBO)
353 			elements--;
354 
355 		omap_set_dma_transfer_params(mcspi_dma->dma_rx_channel,
356 				data_type, elements, 1,
357 				OMAP_DMA_SYNC_ELEMENT,
358 				mcspi_dma->dma_rx_sync_dev, 1);
359 
360 		omap_set_dma_src_params(mcspi_dma->dma_rx_channel, 0,
361 				OMAP_DMA_AMODE_CONSTANT,
362 				rx_reg, 0, 0);
363 
364 		omap_set_dma_dest_params(mcspi_dma->dma_rx_channel, 0,
365 				OMAP_DMA_AMODE_POST_INC,
366 				xfer->rx_dma, 0, 0);
367 	}
368 
369 	if (tx != NULL) {
370 		omap_start_dma(mcspi_dma->dma_tx_channel);
371 		omap2_mcspi_set_dma_req(spi, 0, 1);
372 	}
373 
374 	if (rx != NULL) {
375 		omap_start_dma(mcspi_dma->dma_rx_channel);
376 		omap2_mcspi_set_dma_req(spi, 1, 1);
377 	}
378 
379 	if (tx != NULL) {
380 		wait_for_completion(&mcspi_dma->dma_tx_completion);
381 		dma_unmap_single(&spi->dev, xfer->tx_dma, count, DMA_TO_DEVICE);
382 
383 		/* for TX_ONLY mode, be sure all words have shifted out */
384 		if (rx == NULL) {
385 			if (mcspi_wait_for_reg_bit(chstat_reg,
386 						OMAP2_MCSPI_CHSTAT_TXS) < 0)
387 				dev_err(&spi->dev, "TXS timed out\n");
388 			else if (mcspi_wait_for_reg_bit(chstat_reg,
389 						OMAP2_MCSPI_CHSTAT_EOT) < 0)
390 				dev_err(&spi->dev, "EOT timed out\n");
391 		}
392 	}
393 
394 	if (rx != NULL) {
395 		wait_for_completion(&mcspi_dma->dma_rx_completion);
396 		dma_unmap_single(&spi->dev, xfer->rx_dma, count, DMA_FROM_DEVICE);
397 		omap2_mcspi_set_enable(spi, 0);
398 
399 		if (l & OMAP2_MCSPI_CHCONF_TURBO) {
400 
401 			if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
402 				   & OMAP2_MCSPI_CHSTAT_RXS)) {
403 				u32 w;
404 
405 				w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
406 				if (word_len <= 8)
407 					((u8 *)xfer->rx_buf)[elements++] = w;
408 				else if (word_len <= 16)
409 					((u16 *)xfer->rx_buf)[elements++] = w;
410 				else /* word_len <= 32 */
411 					((u32 *)xfer->rx_buf)[elements++] = w;
412 			} else {
413 				dev_err(&spi->dev,
414 					"DMA RX penultimate word empty");
415 				count -= (word_len <= 8)  ? 2 :
416 					(word_len <= 16) ? 4 :
417 					/* word_len <= 32 */ 8;
418 				omap2_mcspi_set_enable(spi, 1);
419 				return count;
420 			}
421 		}
422 
423 		if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
424 				& OMAP2_MCSPI_CHSTAT_RXS)) {
425 			u32 w;
426 
427 			w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
428 			if (word_len <= 8)
429 				((u8 *)xfer->rx_buf)[elements] = w;
430 			else if (word_len <= 16)
431 				((u16 *)xfer->rx_buf)[elements] = w;
432 			else /* word_len <= 32 */
433 				((u32 *)xfer->rx_buf)[elements] = w;
434 		} else {
435 			dev_err(&spi->dev, "DMA RX last word empty");
436 			count -= (word_len <= 8)  ? 1 :
437 				 (word_len <= 16) ? 2 :
438 			       /* word_len <= 32 */ 4;
439 		}
440 		omap2_mcspi_set_enable(spi, 1);
441 	}
442 	return count;
443 }
444 
445 static unsigned
446 omap2_mcspi_txrx_pio(struct spi_device *spi, struct spi_transfer *xfer)
447 {
448 	struct omap2_mcspi	*mcspi;
449 	struct omap2_mcspi_cs	*cs = spi->controller_state;
450 	unsigned int		count, c;
451 	u32			l;
452 	void __iomem		*base = cs->base;
453 	void __iomem		*tx_reg;
454 	void __iomem		*rx_reg;
455 	void __iomem		*chstat_reg;
456 	int			word_len;
457 
458 	mcspi = spi_master_get_devdata(spi->master);
459 	count = xfer->len;
460 	c = count;
461 	word_len = cs->word_len;
462 
463 	l = mcspi_cached_chconf0(spi);
464 
465 	/* We store the pre-calculated register addresses on stack to speed
466 	 * up the transfer loop. */
467 	tx_reg		= base + OMAP2_MCSPI_TX0;
468 	rx_reg		= base + OMAP2_MCSPI_RX0;
469 	chstat_reg	= base + OMAP2_MCSPI_CHSTAT0;
470 
471 	if (c < (word_len>>3))
472 		return 0;
473 
474 	if (word_len <= 8) {
475 		u8		*rx;
476 		const u8	*tx;
477 
478 		rx = xfer->rx_buf;
479 		tx = xfer->tx_buf;
480 
481 		do {
482 			c -= 1;
483 			if (tx != NULL) {
484 				if (mcspi_wait_for_reg_bit(chstat_reg,
485 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
486 					dev_err(&spi->dev, "TXS timed out\n");
487 					goto out;
488 				}
489 				dev_vdbg(&spi->dev, "write-%d %02x\n",
490 						word_len, *tx);
491 				__raw_writel(*tx++, tx_reg);
492 			}
493 			if (rx != NULL) {
494 				if (mcspi_wait_for_reg_bit(chstat_reg,
495 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
496 					dev_err(&spi->dev, "RXS timed out\n");
497 					goto out;
498 				}
499 
500 				if (c == 1 && tx == NULL &&
501 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
502 					omap2_mcspi_set_enable(spi, 0);
503 					*rx++ = __raw_readl(rx_reg);
504 					dev_vdbg(&spi->dev, "read-%d %02x\n",
505 						    word_len, *(rx - 1));
506 					if (mcspi_wait_for_reg_bit(chstat_reg,
507 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
508 						dev_err(&spi->dev,
509 							"RXS timed out\n");
510 						goto out;
511 					}
512 					c = 0;
513 				} else if (c == 0 && tx == NULL) {
514 					omap2_mcspi_set_enable(spi, 0);
515 				}
516 
517 				*rx++ = __raw_readl(rx_reg);
518 				dev_vdbg(&spi->dev, "read-%d %02x\n",
519 						word_len, *(rx - 1));
520 			}
521 		} while (c);
522 	} else if (word_len <= 16) {
523 		u16		*rx;
524 		const u16	*tx;
525 
526 		rx = xfer->rx_buf;
527 		tx = xfer->tx_buf;
528 		do {
529 			c -= 2;
530 			if (tx != NULL) {
531 				if (mcspi_wait_for_reg_bit(chstat_reg,
532 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
533 					dev_err(&spi->dev, "TXS timed out\n");
534 					goto out;
535 				}
536 				dev_vdbg(&spi->dev, "write-%d %04x\n",
537 						word_len, *tx);
538 				__raw_writel(*tx++, tx_reg);
539 			}
540 			if (rx != NULL) {
541 				if (mcspi_wait_for_reg_bit(chstat_reg,
542 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
543 					dev_err(&spi->dev, "RXS timed out\n");
544 					goto out;
545 				}
546 
547 				if (c == 2 && tx == NULL &&
548 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
549 					omap2_mcspi_set_enable(spi, 0);
550 					*rx++ = __raw_readl(rx_reg);
551 					dev_vdbg(&spi->dev, "read-%d %04x\n",
552 						    word_len, *(rx - 1));
553 					if (mcspi_wait_for_reg_bit(chstat_reg,
554 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
555 						dev_err(&spi->dev,
556 							"RXS timed out\n");
557 						goto out;
558 					}
559 					c = 0;
560 				} else if (c == 0 && tx == NULL) {
561 					omap2_mcspi_set_enable(spi, 0);
562 				}
563 
564 				*rx++ = __raw_readl(rx_reg);
565 				dev_vdbg(&spi->dev, "read-%d %04x\n",
566 						word_len, *(rx - 1));
567 			}
568 		} while (c >= 2);
569 	} else if (word_len <= 32) {
570 		u32		*rx;
571 		const u32	*tx;
572 
573 		rx = xfer->rx_buf;
574 		tx = xfer->tx_buf;
575 		do {
576 			c -= 4;
577 			if (tx != NULL) {
578 				if (mcspi_wait_for_reg_bit(chstat_reg,
579 						OMAP2_MCSPI_CHSTAT_TXS) < 0) {
580 					dev_err(&spi->dev, "TXS timed out\n");
581 					goto out;
582 				}
583 				dev_vdbg(&spi->dev, "write-%d %08x\n",
584 						word_len, *tx);
585 				__raw_writel(*tx++, tx_reg);
586 			}
587 			if (rx != NULL) {
588 				if (mcspi_wait_for_reg_bit(chstat_reg,
589 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
590 					dev_err(&spi->dev, "RXS timed out\n");
591 					goto out;
592 				}
593 
594 				if (c == 4 && tx == NULL &&
595 				    (l & OMAP2_MCSPI_CHCONF_TURBO)) {
596 					omap2_mcspi_set_enable(spi, 0);
597 					*rx++ = __raw_readl(rx_reg);
598 					dev_vdbg(&spi->dev, "read-%d %08x\n",
599 						    word_len, *(rx - 1));
600 					if (mcspi_wait_for_reg_bit(chstat_reg,
601 						OMAP2_MCSPI_CHSTAT_RXS) < 0) {
602 						dev_err(&spi->dev,
603 							"RXS timed out\n");
604 						goto out;
605 					}
606 					c = 0;
607 				} else if (c == 0 && tx == NULL) {
608 					omap2_mcspi_set_enable(spi, 0);
609 				}
610 
611 				*rx++ = __raw_readl(rx_reg);
612 				dev_vdbg(&spi->dev, "read-%d %08x\n",
613 						word_len, *(rx - 1));
614 			}
615 		} while (c >= 4);
616 	}
617 
618 	/* for TX_ONLY mode, be sure all words have shifted out */
619 	if (xfer->rx_buf == 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 		} else if (mcspi_wait_for_reg_bit(chstat_reg,
624 				OMAP2_MCSPI_CHSTAT_EOT) < 0)
625 			dev_err(&spi->dev, "EOT timed out\n");
626 
627 		/* disable chan to purge rx datas received in TX_ONLY transfer,
628 		 * otherwise these rx datas will affect the direct following
629 		 * RX_ONLY transfer.
630 		 */
631 		omap2_mcspi_set_enable(spi, 0);
632 	}
633 out:
634 	omap2_mcspi_set_enable(spi, 1);
635 	return count - c;
636 }
637 
638 static u32 omap2_mcspi_calc_divisor(u32 speed_hz)
639 {
640 	u32 div;
641 
642 	for (div = 0; div < 15; div++)
643 		if (speed_hz >= (OMAP2_MCSPI_MAX_FREQ >> div))
644 			return div;
645 
646 	return 15;
647 }
648 
649 /* called only when no transfer is active to this device */
650 static int omap2_mcspi_setup_transfer(struct spi_device *spi,
651 		struct spi_transfer *t)
652 {
653 	struct omap2_mcspi_cs *cs = spi->controller_state;
654 	struct omap2_mcspi *mcspi;
655 	struct spi_master *spi_cntrl;
656 	u32 l = 0, div = 0;
657 	u8 word_len = spi->bits_per_word;
658 	u32 speed_hz = spi->max_speed_hz;
659 
660 	mcspi = spi_master_get_devdata(spi->master);
661 	spi_cntrl = mcspi->master;
662 
663 	if (t != NULL && t->bits_per_word)
664 		word_len = t->bits_per_word;
665 
666 	cs->word_len = word_len;
667 
668 	if (t && t->speed_hz)
669 		speed_hz = t->speed_hz;
670 
671 	speed_hz = min_t(u32, speed_hz, OMAP2_MCSPI_MAX_FREQ);
672 	div = omap2_mcspi_calc_divisor(speed_hz);
673 
674 	l = mcspi_cached_chconf0(spi);
675 
676 	/* standard 4-wire master mode:  SCK, MOSI/out, MISO/in, nCS
677 	 * REVISIT: this controller could support SPI_3WIRE mode.
678 	 */
679 	l &= ~(OMAP2_MCSPI_CHCONF_IS|OMAP2_MCSPI_CHCONF_DPE1);
680 	l |= OMAP2_MCSPI_CHCONF_DPE0;
681 
682 	/* wordlength */
683 	l &= ~OMAP2_MCSPI_CHCONF_WL_MASK;
684 	l |= (word_len - 1) << 7;
685 
686 	/* set chipselect polarity; manage with FORCE */
687 	if (!(spi->mode & SPI_CS_HIGH))
688 		l |= OMAP2_MCSPI_CHCONF_EPOL;	/* active-low; normal */
689 	else
690 		l &= ~OMAP2_MCSPI_CHCONF_EPOL;
691 
692 	/* set clock divisor */
693 	l &= ~OMAP2_MCSPI_CHCONF_CLKD_MASK;
694 	l |= div << 2;
695 
696 	/* set SPI mode 0..3 */
697 	if (spi->mode & SPI_CPOL)
698 		l |= OMAP2_MCSPI_CHCONF_POL;
699 	else
700 		l &= ~OMAP2_MCSPI_CHCONF_POL;
701 	if (spi->mode & SPI_CPHA)
702 		l |= OMAP2_MCSPI_CHCONF_PHA;
703 	else
704 		l &= ~OMAP2_MCSPI_CHCONF_PHA;
705 
706 	mcspi_write_chconf0(spi, l);
707 
708 	dev_dbg(&spi->dev, "setup: speed %d, sample %s edge, clk %s\n",
709 			OMAP2_MCSPI_MAX_FREQ >> div,
710 			(spi->mode & SPI_CPHA) ? "trailing" : "leading",
711 			(spi->mode & SPI_CPOL) ? "inverted" : "normal");
712 
713 	return 0;
714 }
715 
716 static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
717 {
718 	struct spi_device	*spi = data;
719 	struct omap2_mcspi	*mcspi;
720 	struct omap2_mcspi_dma	*mcspi_dma;
721 
722 	mcspi = spi_master_get_devdata(spi->master);
723 	mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
724 
725 	complete(&mcspi_dma->dma_rx_completion);
726 
727 	/* We must disable the DMA RX request */
728 	omap2_mcspi_set_dma_req(spi, 1, 0);
729 }
730 
731 static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
732 {
733 	struct spi_device	*spi = data;
734 	struct omap2_mcspi	*mcspi;
735 	struct omap2_mcspi_dma	*mcspi_dma;
736 
737 	mcspi = spi_master_get_devdata(spi->master);
738 	mcspi_dma = &(mcspi->dma_channels[spi->chip_select]);
739 
740 	complete(&mcspi_dma->dma_tx_completion);
741 
742 	/* We must disable the DMA TX request */
743 	omap2_mcspi_set_dma_req(spi, 0, 0);
744 }
745 
746 static int omap2_mcspi_request_dma(struct spi_device *spi)
747 {
748 	struct spi_master	*master = spi->master;
749 	struct omap2_mcspi	*mcspi;
750 	struct omap2_mcspi_dma	*mcspi_dma;
751 
752 	mcspi = spi_master_get_devdata(master);
753 	mcspi_dma = mcspi->dma_channels + spi->chip_select;
754 
755 	if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
756 			omap2_mcspi_dma_rx_callback, spi,
757 			&mcspi_dma->dma_rx_channel)) {
758 		dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
759 		return -EAGAIN;
760 	}
761 
762 	if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
763 			omap2_mcspi_dma_tx_callback, spi,
764 			&mcspi_dma->dma_tx_channel)) {
765 		omap_free_dma(mcspi_dma->dma_rx_channel);
766 		mcspi_dma->dma_rx_channel = -1;
767 		dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
768 		return -EAGAIN;
769 	}
770 
771 	init_completion(&mcspi_dma->dma_rx_completion);
772 	init_completion(&mcspi_dma->dma_tx_completion);
773 
774 	return 0;
775 }
776 
777 static int omap2_mcspi_setup(struct spi_device *spi)
778 {
779 	int			ret;
780 	struct omap2_mcspi	*mcspi;
781 	struct omap2_mcspi_dma	*mcspi_dma;
782 	struct omap2_mcspi_cs	*cs = spi->controller_state;
783 
784 	if (spi->bits_per_word < 4 || spi->bits_per_word > 32) {
785 		dev_dbg(&spi->dev, "setup: unsupported %d bit words\n",
786 			spi->bits_per_word);
787 		return -EINVAL;
788 	}
789 
790 	mcspi = spi_master_get_devdata(spi->master);
791 	mcspi_dma = &mcspi->dma_channels[spi->chip_select];
792 
793 	if (!cs) {
794 		cs = kzalloc(sizeof *cs, GFP_KERNEL);
795 		if (!cs)
796 			return -ENOMEM;
797 		cs->base = mcspi->base + spi->chip_select * 0x14;
798 		cs->phys = mcspi->phys + spi->chip_select * 0x14;
799 		cs->chconf0 = 0;
800 		spi->controller_state = cs;
801 		/* Link this to context save list */
802 		list_add_tail(&cs->node,
803 			&omap2_mcspi_ctx[mcspi->master->bus_num - 1].cs);
804 	}
805 
806 	if (mcspi_dma->dma_rx_channel == -1
807 			|| mcspi_dma->dma_tx_channel == -1) {
808 		ret = omap2_mcspi_request_dma(spi);
809 		if (ret < 0)
810 			return ret;
811 	}
812 
813 	ret = omap2_mcspi_enable_clocks(mcspi);
814 	if (ret < 0)
815 		return ret;
816 
817 	ret = omap2_mcspi_setup_transfer(spi, NULL);
818 	omap2_mcspi_disable_clocks(mcspi);
819 
820 	return ret;
821 }
822 
823 static void omap2_mcspi_cleanup(struct spi_device *spi)
824 {
825 	struct omap2_mcspi	*mcspi;
826 	struct omap2_mcspi_dma	*mcspi_dma;
827 	struct omap2_mcspi_cs	*cs;
828 
829 	mcspi = spi_master_get_devdata(spi->master);
830 
831 	if (spi->controller_state) {
832 		/* Unlink controller state from context save list */
833 		cs = spi->controller_state;
834 		list_del(&cs->node);
835 
836 		kfree(spi->controller_state);
837 	}
838 
839 	if (spi->chip_select < spi->master->num_chipselect) {
840 		mcspi_dma = &mcspi->dma_channels[spi->chip_select];
841 
842 		if (mcspi_dma->dma_rx_channel != -1) {
843 			omap_free_dma(mcspi_dma->dma_rx_channel);
844 			mcspi_dma->dma_rx_channel = -1;
845 		}
846 		if (mcspi_dma->dma_tx_channel != -1) {
847 			omap_free_dma(mcspi_dma->dma_tx_channel);
848 			mcspi_dma->dma_tx_channel = -1;
849 		}
850 	}
851 }
852 
853 static void omap2_mcspi_work(struct work_struct *work)
854 {
855 	struct omap2_mcspi	*mcspi;
856 
857 	mcspi = container_of(work, struct omap2_mcspi, work);
858 
859 	if (omap2_mcspi_enable_clocks(mcspi) < 0)
860 		return;
861 
862 	spin_lock_irq(&mcspi->lock);
863 
864 	/* We only enable one channel at a time -- the one whose message is
865 	 * at the head of the queue -- although this controller would gladly
866 	 * arbitrate among multiple channels.  This corresponds to "single
867 	 * channel" master mode.  As a side effect, we need to manage the
868 	 * chipselect with the FORCE bit ... CS != channel enable.
869 	 */
870 	while (!list_empty(&mcspi->msg_queue)) {
871 		struct spi_message		*m;
872 		struct spi_device		*spi;
873 		struct spi_transfer		*t = NULL;
874 		int				cs_active = 0;
875 		struct omap2_mcspi_cs		*cs;
876 		struct omap2_mcspi_device_config *cd;
877 		int				par_override = 0;
878 		int				status = 0;
879 		u32				chconf;
880 
881 		m = container_of(mcspi->msg_queue.next, struct spi_message,
882 				 queue);
883 
884 		list_del_init(&m->queue);
885 		spin_unlock_irq(&mcspi->lock);
886 
887 		spi = m->spi;
888 		cs = spi->controller_state;
889 		cd = spi->controller_data;
890 
891 		omap2_mcspi_set_enable(spi, 1);
892 		list_for_each_entry(t, &m->transfers, transfer_list) {
893 			if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
894 				status = -EINVAL;
895 				break;
896 			}
897 			if (par_override || t->speed_hz || t->bits_per_word) {
898 				par_override = 1;
899 				status = omap2_mcspi_setup_transfer(spi, t);
900 				if (status < 0)
901 					break;
902 				if (!t->speed_hz && !t->bits_per_word)
903 					par_override = 0;
904 			}
905 
906 			if (!cs_active) {
907 				omap2_mcspi_force_cs(spi, 1);
908 				cs_active = 1;
909 			}
910 
911 			chconf = mcspi_cached_chconf0(spi);
912 			chconf &= ~OMAP2_MCSPI_CHCONF_TRM_MASK;
913 			chconf &= ~OMAP2_MCSPI_CHCONF_TURBO;
914 
915 			if (t->tx_buf == NULL)
916 				chconf |= OMAP2_MCSPI_CHCONF_TRM_RX_ONLY;
917 			else if (t->rx_buf == NULL)
918 				chconf |= OMAP2_MCSPI_CHCONF_TRM_TX_ONLY;
919 
920 			if (cd && cd->turbo_mode && t->tx_buf == NULL) {
921 				/* Turbo mode is for more than one word */
922 				if (t->len > ((cs->word_len + 7) >> 3))
923 					chconf |= OMAP2_MCSPI_CHCONF_TURBO;
924 			}
925 
926 			mcspi_write_chconf0(spi, chconf);
927 
928 			if (t->len) {
929 				unsigned	count;
930 
931 				/* RX_ONLY mode needs dummy data in TX reg */
932 				if (t->tx_buf == NULL)
933 					__raw_writel(0, cs->base
934 							+ OMAP2_MCSPI_TX0);
935 
936 				if (m->is_dma_mapped || t->len >= DMA_MIN_BYTES)
937 					count = omap2_mcspi_txrx_dma(spi, t);
938 				else
939 					count = omap2_mcspi_txrx_pio(spi, t);
940 				m->actual_length += count;
941 
942 				if (count != t->len) {
943 					status = -EIO;
944 					break;
945 				}
946 			}
947 
948 			if (t->delay_usecs)
949 				udelay(t->delay_usecs);
950 
951 			/* ignore the "leave it on after last xfer" hint */
952 			if (t->cs_change) {
953 				omap2_mcspi_force_cs(spi, 0);
954 				cs_active = 0;
955 			}
956 		}
957 
958 		/* Restore defaults if they were overriden */
959 		if (par_override) {
960 			par_override = 0;
961 			status = omap2_mcspi_setup_transfer(spi, NULL);
962 		}
963 
964 		if (cs_active)
965 			omap2_mcspi_force_cs(spi, 0);
966 
967 		omap2_mcspi_set_enable(spi, 0);
968 
969 		m->status = status;
970 		m->complete(m->context);
971 
972 		spin_lock_irq(&mcspi->lock);
973 	}
974 
975 	spin_unlock_irq(&mcspi->lock);
976 
977 	omap2_mcspi_disable_clocks(mcspi);
978 }
979 
980 static int omap2_mcspi_transfer(struct spi_device *spi, struct spi_message *m)
981 {
982 	struct omap2_mcspi	*mcspi;
983 	unsigned long		flags;
984 	struct spi_transfer	*t;
985 
986 	m->actual_length = 0;
987 	m->status = 0;
988 
989 	/* reject invalid messages and transfers */
990 	if (list_empty(&m->transfers) || !m->complete)
991 		return -EINVAL;
992 	list_for_each_entry(t, &m->transfers, transfer_list) {
993 		const void	*tx_buf = t->tx_buf;
994 		void		*rx_buf = t->rx_buf;
995 		unsigned	len = t->len;
996 
997 		if (t->speed_hz > OMAP2_MCSPI_MAX_FREQ
998 				|| (len && !(rx_buf || tx_buf))
999 				|| (t->bits_per_word &&
1000 					(  t->bits_per_word < 4
1001 					|| t->bits_per_word > 32))) {
1002 			dev_dbg(&spi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
1003 					t->speed_hz,
1004 					len,
1005 					tx_buf ? "tx" : "",
1006 					rx_buf ? "rx" : "",
1007 					t->bits_per_word);
1008 			return -EINVAL;
1009 		}
1010 		if (t->speed_hz && t->speed_hz < (OMAP2_MCSPI_MAX_FREQ >> 15)) {
1011 			dev_dbg(&spi->dev, "speed_hz %d below minimum %d Hz\n",
1012 				t->speed_hz,
1013 				OMAP2_MCSPI_MAX_FREQ >> 15);
1014 			return -EINVAL;
1015 		}
1016 
1017 		if (m->is_dma_mapped || len < DMA_MIN_BYTES)
1018 			continue;
1019 
1020 		if (tx_buf != NULL) {
1021 			t->tx_dma = dma_map_single(&spi->dev, (void *) tx_buf,
1022 					len, DMA_TO_DEVICE);
1023 			if (dma_mapping_error(&spi->dev, t->tx_dma)) {
1024 				dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
1025 						'T', len);
1026 				return -EINVAL;
1027 			}
1028 		}
1029 		if (rx_buf != NULL) {
1030 			t->rx_dma = dma_map_single(&spi->dev, rx_buf, t->len,
1031 					DMA_FROM_DEVICE);
1032 			if (dma_mapping_error(&spi->dev, t->rx_dma)) {
1033 				dev_dbg(&spi->dev, "dma %cX %d bytes error\n",
1034 						'R', len);
1035 				if (tx_buf != NULL)
1036 					dma_unmap_single(&spi->dev, t->tx_dma,
1037 							len, DMA_TO_DEVICE);
1038 				return -EINVAL;
1039 			}
1040 		}
1041 	}
1042 
1043 	mcspi = spi_master_get_devdata(spi->master);
1044 
1045 	spin_lock_irqsave(&mcspi->lock, flags);
1046 	list_add_tail(&m->queue, &mcspi->msg_queue);
1047 	queue_work(mcspi->wq, &mcspi->work);
1048 	spin_unlock_irqrestore(&mcspi->lock, flags);
1049 
1050 	return 0;
1051 }
1052 
1053 static int __init omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
1054 {
1055 	struct spi_master	*master = mcspi->master;
1056 	u32			tmp;
1057 	int ret = 0;
1058 
1059 	ret = omap2_mcspi_enable_clocks(mcspi);
1060 	if (ret < 0)
1061 		return ret;
1062 
1063 	tmp = OMAP2_MCSPI_WAKEUPENABLE_WKEN;
1064 	mcspi_write_reg(master, OMAP2_MCSPI_WAKEUPENABLE, tmp);
1065 	omap2_mcspi_ctx[master->bus_num - 1].wakeupenable = tmp;
1066 
1067 	omap2_mcspi_set_master_mode(master);
1068 	omap2_mcspi_disable_clocks(mcspi);
1069 	return 0;
1070 }
1071 
1072 static int omap_mcspi_runtime_resume(struct device *dev)
1073 {
1074 	struct omap2_mcspi	*mcspi;
1075 	struct spi_master	*master;
1076 
1077 	master = dev_get_drvdata(dev);
1078 	mcspi = spi_master_get_devdata(master);
1079 	omap2_mcspi_restore_ctx(mcspi);
1080 
1081 	return 0;
1082 }
1083 
1084 static struct omap2_mcspi_platform_config omap2_pdata = {
1085 	.regs_offset = 0,
1086 };
1087 
1088 static struct omap2_mcspi_platform_config omap4_pdata = {
1089 	.regs_offset = OMAP4_MCSPI_REG_OFFSET,
1090 };
1091 
1092 static const struct of_device_id omap_mcspi_of_match[] = {
1093 	{
1094 		.compatible = "ti,omap2-mcspi",
1095 		.data = &omap2_pdata,
1096 	},
1097 	{
1098 		.compatible = "ti,omap4-mcspi",
1099 		.data = &omap4_pdata,
1100 	},
1101 	{ },
1102 };
1103 MODULE_DEVICE_TABLE(of, omap_mcspi_of_match);
1104 
1105 static int __init omap2_mcspi_probe(struct platform_device *pdev)
1106 {
1107 	struct spi_master	*master;
1108 	struct omap2_mcspi_platform_config *pdata;
1109 	struct omap2_mcspi	*mcspi;
1110 	struct resource		*r;
1111 	int			status = 0, i;
1112 	char			wq_name[20];
1113 	u32			regs_offset = 0;
1114 	static int		bus_num = 1;
1115 	struct device_node	*node = pdev->dev.of_node;
1116 	const struct of_device_id *match;
1117 
1118 	master = spi_alloc_master(&pdev->dev, sizeof *mcspi);
1119 	if (master == NULL) {
1120 		dev_dbg(&pdev->dev, "master allocation failed\n");
1121 		return -ENOMEM;
1122 	}
1123 
1124 	/* the spi->mode bits understood by this driver: */
1125 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
1126 
1127 	master->setup = omap2_mcspi_setup;
1128 	master->transfer = omap2_mcspi_transfer;
1129 	master->cleanup = omap2_mcspi_cleanup;
1130 	master->dev.of_node = node;
1131 
1132 	match = of_match_device(omap_mcspi_of_match, &pdev->dev);
1133 	if (match) {
1134 		u32 num_cs = 1; /* default number of chipselect */
1135 		pdata = match->data;
1136 
1137 		of_property_read_u32(node, "ti,spi-num-cs", &num_cs);
1138 		master->num_chipselect = num_cs;
1139 		master->bus_num = bus_num++;
1140 	} else {
1141 		pdata = pdev->dev.platform_data;
1142 		master->num_chipselect = pdata->num_cs;
1143 		if (pdev->id != -1)
1144 			master->bus_num = pdev->id;
1145 	}
1146 	regs_offset = pdata->regs_offset;
1147 
1148 	dev_set_drvdata(&pdev->dev, master);
1149 
1150 	mcspi = spi_master_get_devdata(master);
1151 	mcspi->master = master;
1152 
1153 	sprintf(wq_name, "omap2_mcspi/%d", master->bus_num);
1154 	mcspi->wq = alloc_workqueue(wq_name, WQ_MEM_RECLAIM, 1);
1155 	if (mcspi->wq == NULL) {
1156 		status = -ENOMEM;
1157 		goto free_master;
1158 	}
1159 
1160 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1161 	if (r == NULL) {
1162 		status = -ENODEV;
1163 		goto free_master;
1164 	}
1165 
1166 	r->start += regs_offset;
1167 	r->end += regs_offset;
1168 	mcspi->phys = r->start;
1169 	if (!request_mem_region(r->start, resource_size(r),
1170 				dev_name(&pdev->dev))) {
1171 		status = -EBUSY;
1172 		goto free_master;
1173 	}
1174 
1175 	mcspi->base = ioremap(r->start, resource_size(r));
1176 	if (!mcspi->base) {
1177 		dev_dbg(&pdev->dev, "can't ioremap MCSPI\n");
1178 		status = -ENOMEM;
1179 		goto release_region;
1180 	}
1181 
1182 	mcspi->dev = &pdev->dev;
1183 	INIT_WORK(&mcspi->work, omap2_mcspi_work);
1184 
1185 	spin_lock_init(&mcspi->lock);
1186 	INIT_LIST_HEAD(&mcspi->msg_queue);
1187 	INIT_LIST_HEAD(&omap2_mcspi_ctx[master->bus_num - 1].cs);
1188 
1189 	mcspi->dma_channels = kcalloc(master->num_chipselect,
1190 			sizeof(struct omap2_mcspi_dma),
1191 			GFP_KERNEL);
1192 
1193 	if (mcspi->dma_channels == NULL)
1194 		goto unmap_io;
1195 
1196 	for (i = 0; i < master->num_chipselect; i++) {
1197 		char dma_ch_name[14];
1198 		struct resource *dma_res;
1199 
1200 		sprintf(dma_ch_name, "rx%d", i);
1201 		dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA,
1202 							dma_ch_name);
1203 		if (!dma_res) {
1204 			dev_dbg(&pdev->dev, "cannot get DMA RX channel\n");
1205 			status = -ENODEV;
1206 			break;
1207 		}
1208 
1209 		mcspi->dma_channels[i].dma_rx_channel = -1;
1210 		mcspi->dma_channels[i].dma_rx_sync_dev = dma_res->start;
1211 		sprintf(dma_ch_name, "tx%d", i);
1212 		dma_res = platform_get_resource_byname(pdev, IORESOURCE_DMA,
1213 							dma_ch_name);
1214 		if (!dma_res) {
1215 			dev_dbg(&pdev->dev, "cannot get DMA TX channel\n");
1216 			status = -ENODEV;
1217 			break;
1218 		}
1219 
1220 		mcspi->dma_channels[i].dma_tx_channel = -1;
1221 		mcspi->dma_channels[i].dma_tx_sync_dev = dma_res->start;
1222 	}
1223 
1224 	if (status < 0)
1225 		goto dma_chnl_free;
1226 
1227 	pm_runtime_enable(&pdev->dev);
1228 
1229 	if (status || omap2_mcspi_master_setup(mcspi) < 0)
1230 		goto disable_pm;
1231 
1232 	status = spi_register_master(master);
1233 	if (status < 0)
1234 		goto err_spi_register;
1235 
1236 	return status;
1237 
1238 err_spi_register:
1239 	spi_master_put(master);
1240 disable_pm:
1241 	pm_runtime_disable(&pdev->dev);
1242 dma_chnl_free:
1243 	kfree(mcspi->dma_channels);
1244 unmap_io:
1245 	iounmap(mcspi->base);
1246 release_region:
1247 	release_mem_region(r->start, resource_size(r));
1248 free_master:
1249 	kfree(master);
1250 	platform_set_drvdata(pdev, NULL);
1251 	return status;
1252 }
1253 
1254 static int __exit omap2_mcspi_remove(struct platform_device *pdev)
1255 {
1256 	struct spi_master	*master;
1257 	struct omap2_mcspi	*mcspi;
1258 	struct omap2_mcspi_dma	*dma_channels;
1259 	struct resource		*r;
1260 	void __iomem *base;
1261 
1262 	master = dev_get_drvdata(&pdev->dev);
1263 	mcspi = spi_master_get_devdata(master);
1264 	dma_channels = mcspi->dma_channels;
1265 
1266 	omap2_mcspi_disable_clocks(mcspi);
1267 	pm_runtime_disable(&pdev->dev);
1268 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1269 	release_mem_region(r->start, resource_size(r));
1270 
1271 	base = mcspi->base;
1272 	spi_unregister_master(master);
1273 	iounmap(base);
1274 	kfree(dma_channels);
1275 	destroy_workqueue(mcspi->wq);
1276 	platform_set_drvdata(pdev, NULL);
1277 
1278 	return 0;
1279 }
1280 
1281 /* work with hotplug and coldplug */
1282 MODULE_ALIAS("platform:omap2_mcspi");
1283 
1284 #ifdef	CONFIG_SUSPEND
1285 /*
1286  * When SPI wake up from off-mode, CS is in activate state. If it was in
1287  * unactive state when driver was suspend, then force it to unactive state at
1288  * wake up.
1289  */
1290 static int omap2_mcspi_resume(struct device *dev)
1291 {
1292 	struct spi_master	*master = dev_get_drvdata(dev);
1293 	struct omap2_mcspi	*mcspi = spi_master_get_devdata(master);
1294 	struct omap2_mcspi_cs *cs;
1295 
1296 	omap2_mcspi_enable_clocks(mcspi);
1297 	list_for_each_entry(cs, &omap2_mcspi_ctx[master->bus_num - 1].cs,
1298 			    node) {
1299 		if ((cs->chconf0 & OMAP2_MCSPI_CHCONF_FORCE) == 0) {
1300 
1301 			/*
1302 			 * We need to toggle CS state for OMAP take this
1303 			 * change in account.
1304 			 */
1305 			MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 1);
1306 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1307 			MOD_REG_BIT(cs->chconf0, OMAP2_MCSPI_CHCONF_FORCE, 0);
1308 			__raw_writel(cs->chconf0, cs->base + OMAP2_MCSPI_CHCONF0);
1309 		}
1310 	}
1311 	omap2_mcspi_disable_clocks(mcspi);
1312 	return 0;
1313 }
1314 #else
1315 #define	omap2_mcspi_resume	NULL
1316 #endif
1317 
1318 static const struct dev_pm_ops omap2_mcspi_pm_ops = {
1319 	.resume = omap2_mcspi_resume,
1320 	.runtime_resume	= omap_mcspi_runtime_resume,
1321 };
1322 
1323 static struct platform_driver omap2_mcspi_driver = {
1324 	.driver = {
1325 		.name =		"omap2_mcspi",
1326 		.owner =	THIS_MODULE,
1327 		.pm =		&omap2_mcspi_pm_ops,
1328 		.of_match_table = omap_mcspi_of_match,
1329 	},
1330 	.remove =	__exit_p(omap2_mcspi_remove),
1331 };
1332 
1333 
1334 static int __init omap2_mcspi_init(void)
1335 {
1336 	return platform_driver_probe(&omap2_mcspi_driver, omap2_mcspi_probe);
1337 }
1338 subsys_initcall(omap2_mcspi_init);
1339 
1340 static void __exit omap2_mcspi_exit(void)
1341 {
1342 	platform_driver_unregister(&omap2_mcspi_driver);
1343 
1344 }
1345 module_exit(omap2_mcspi_exit);
1346 
1347 MODULE_LICENSE("GPL");
1348