1 /*
2  * Driver for Nvidia TEGRA spi controller.
3  *
4  * Copyright (C) 2010 Google, Inc.
5  *
6  * Author:
7  *     Erik Gilling <konkers@android.com>
8  *
9  * This software is licensed under the terms of the GNU General Public
10  * License version 2, as published by the Free Software Foundation, and
11  * may be copied, distributed, and modified under those terms.
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  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/err.h>
24 #include <linux/platform_device.h>
25 #include <linux/io.h>
26 #include <linux/dma-mapping.h>
27 #include <linux/dmapool.h>
28 #include <linux/clk.h>
29 #include <linux/interrupt.h>
30 #include <linux/delay.h>
31 
32 #include <linux/spi/spi.h>
33 
34 #include <mach/dma.h>
35 
36 #define SLINK_COMMAND		0x000
37 #define   SLINK_BIT_LENGTH(x)		(((x) & 0x1f) << 0)
38 #define   SLINK_WORD_SIZE(x)		(((x) & 0x1f) << 5)
39 #define   SLINK_BOTH_EN			(1 << 10)
40 #define   SLINK_CS_SW			(1 << 11)
41 #define   SLINK_CS_VALUE		(1 << 12)
42 #define   SLINK_CS_POLARITY		(1 << 13)
43 #define   SLINK_IDLE_SDA_DRIVE_LOW	(0 << 16)
44 #define   SLINK_IDLE_SDA_DRIVE_HIGH	(1 << 16)
45 #define   SLINK_IDLE_SDA_PULL_LOW	(2 << 16)
46 #define   SLINK_IDLE_SDA_PULL_HIGH	(3 << 16)
47 #define   SLINK_IDLE_SDA_MASK		(3 << 16)
48 #define   SLINK_CS_POLARITY1		(1 << 20)
49 #define   SLINK_CK_SDA			(1 << 21)
50 #define   SLINK_CS_POLARITY2		(1 << 22)
51 #define   SLINK_CS_POLARITY3		(1 << 23)
52 #define   SLINK_IDLE_SCLK_DRIVE_LOW	(0 << 24)
53 #define   SLINK_IDLE_SCLK_DRIVE_HIGH	(1 << 24)
54 #define   SLINK_IDLE_SCLK_PULL_LOW	(2 << 24)
55 #define   SLINK_IDLE_SCLK_PULL_HIGH	(3 << 24)
56 #define   SLINK_IDLE_SCLK_MASK		(3 << 24)
57 #define   SLINK_M_S			(1 << 28)
58 #define   SLINK_WAIT			(1 << 29)
59 #define   SLINK_GO			(1 << 30)
60 #define   SLINK_ENB			(1 << 31)
61 
62 #define SLINK_COMMAND2		0x004
63 #define   SLINK_LSBFE			(1 << 0)
64 #define   SLINK_SSOE			(1 << 1)
65 #define   SLINK_SPIE			(1 << 4)
66 #define   SLINK_BIDIROE			(1 << 6)
67 #define   SLINK_MODFEN			(1 << 7)
68 #define   SLINK_INT_SIZE(x)		(((x) & 0x1f) << 8)
69 #define   SLINK_CS_ACTIVE_BETWEEN	(1 << 17)
70 #define   SLINK_SS_EN_CS(x)		(((x) & 0x3) << 18)
71 #define   SLINK_SS_SETUP(x)		(((x) & 0x3) << 20)
72 #define   SLINK_FIFO_REFILLS_0		(0 << 22)
73 #define   SLINK_FIFO_REFILLS_1		(1 << 22)
74 #define   SLINK_FIFO_REFILLS_2		(2 << 22)
75 #define   SLINK_FIFO_REFILLS_3		(3 << 22)
76 #define   SLINK_FIFO_REFILLS_MASK	(3 << 22)
77 #define   SLINK_WAIT_PACK_INT(x)	(((x) & 0x7) << 26)
78 #define   SLINK_SPC0			(1 << 29)
79 #define   SLINK_TXEN			(1 << 30)
80 #define   SLINK_RXEN			(1 << 31)
81 
82 #define SLINK_STATUS		0x008
83 #define   SLINK_COUNT(val)		(((val) >> 0) & 0x1f)
84 #define   SLINK_WORD(val)		(((val) >> 5) & 0x1f)
85 #define   SLINK_BLK_CNT(val)		(((val) >> 0) & 0xffff)
86 #define   SLINK_MODF			(1 << 16)
87 #define   SLINK_RX_UNF			(1 << 18)
88 #define   SLINK_TX_OVF			(1 << 19)
89 #define   SLINK_TX_FULL			(1 << 20)
90 #define   SLINK_TX_EMPTY		(1 << 21)
91 #define   SLINK_RX_FULL			(1 << 22)
92 #define   SLINK_RX_EMPTY		(1 << 23)
93 #define   SLINK_TX_UNF			(1 << 24)
94 #define   SLINK_RX_OVF			(1 << 25)
95 #define   SLINK_TX_FLUSH		(1 << 26)
96 #define   SLINK_RX_FLUSH		(1 << 27)
97 #define   SLINK_SCLK			(1 << 28)
98 #define   SLINK_ERR			(1 << 29)
99 #define   SLINK_RDY			(1 << 30)
100 #define   SLINK_BSY			(1 << 31)
101 
102 #define SLINK_MAS_DATA		0x010
103 #define SLINK_SLAVE_DATA	0x014
104 
105 #define SLINK_DMA_CTL		0x018
106 #define   SLINK_DMA_BLOCK_SIZE(x)	(((x) & 0xffff) << 0)
107 #define   SLINK_TX_TRIG_1		(0 << 16)
108 #define   SLINK_TX_TRIG_4		(1 << 16)
109 #define   SLINK_TX_TRIG_8		(2 << 16)
110 #define   SLINK_TX_TRIG_16		(3 << 16)
111 #define   SLINK_TX_TRIG_MASK		(3 << 16)
112 #define   SLINK_RX_TRIG_1		(0 << 18)
113 #define   SLINK_RX_TRIG_4		(1 << 18)
114 #define   SLINK_RX_TRIG_8		(2 << 18)
115 #define   SLINK_RX_TRIG_16		(3 << 18)
116 #define   SLINK_RX_TRIG_MASK		(3 << 18)
117 #define   SLINK_PACKED			(1 << 20)
118 #define   SLINK_PACK_SIZE_4		(0 << 21)
119 #define   SLINK_PACK_SIZE_8		(1 << 21)
120 #define   SLINK_PACK_SIZE_16		(2 << 21)
121 #define   SLINK_PACK_SIZE_32		(3 << 21)
122 #define   SLINK_PACK_SIZE_MASK		(3 << 21)
123 #define   SLINK_IE_TXC			(1 << 26)
124 #define   SLINK_IE_RXC			(1 << 27)
125 #define   SLINK_DMA_EN			(1 << 31)
126 
127 #define SLINK_STATUS2		0x01c
128 #define   SLINK_TX_FIFO_EMPTY_COUNT(val)	(((val) & 0x3f) >> 0)
129 #define   SLINK_RX_FIFO_FULL_COUNT(val)		(((val) & 0x3f) >> 16)
130 
131 #define SLINK_TX_FIFO		0x100
132 #define SLINK_RX_FIFO		0x180
133 
134 static const unsigned long spi_tegra_req_sels[] = {
135 	TEGRA_DMA_REQ_SEL_SL2B1,
136 	TEGRA_DMA_REQ_SEL_SL2B2,
137 	TEGRA_DMA_REQ_SEL_SL2B3,
138 	TEGRA_DMA_REQ_SEL_SL2B4,
139 };
140 
141 #define BB_LEN			32
142 
143 struct spi_tegra_data {
144 	struct spi_master	*master;
145 	struct platform_device	*pdev;
146 	spinlock_t		lock;
147 
148 	struct clk		*clk;
149 	void __iomem		*base;
150 	unsigned long		phys;
151 
152 	u32			cur_speed;
153 
154 	struct list_head	queue;
155 	struct spi_transfer	*cur;
156 	unsigned		cur_pos;
157 	unsigned		cur_len;
158 	unsigned		cur_bytes_per_word;
159 
160 	/* The tegra spi controller has a bug which causes the first word
161 	 * in PIO transactions to be garbage.  Since packed DMA transactions
162 	 * require transfers to be 4 byte aligned we need a bounce buffer
163 	 * for the generic case.
164 	 */
165 	struct tegra_dma_req	rx_dma_req;
166 	struct tegra_dma_channel *rx_dma;
167 	u32			*rx_bb;
168 	dma_addr_t		rx_bb_phys;
169 };
170 
171 
spi_tegra_readl(struct spi_tegra_data * tspi,unsigned long reg)172 static inline unsigned long spi_tegra_readl(struct spi_tegra_data *tspi,
173 					    unsigned long reg)
174 {
175 	return readl(tspi->base + reg);
176 }
177 
spi_tegra_writel(struct spi_tegra_data * tspi,unsigned long val,unsigned long reg)178 static inline void spi_tegra_writel(struct spi_tegra_data *tspi,
179 				    unsigned long val,
180 				    unsigned long reg)
181 {
182 	writel(val, tspi->base + reg);
183 }
184 
spi_tegra_go(struct spi_tegra_data * tspi)185 static void spi_tegra_go(struct spi_tegra_data *tspi)
186 {
187 	unsigned long val;
188 
189 	wmb();
190 
191 	val = spi_tegra_readl(tspi, SLINK_DMA_CTL);
192 	val &= ~SLINK_DMA_BLOCK_SIZE(~0) & ~SLINK_DMA_EN;
193 	val |= SLINK_DMA_BLOCK_SIZE(tspi->rx_dma_req.size / 4 - 1);
194 	spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
195 
196 	tegra_dma_enqueue_req(tspi->rx_dma, &tspi->rx_dma_req);
197 
198 	val |= SLINK_DMA_EN;
199 	spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
200 }
201 
spi_tegra_fill_tx_fifo(struct spi_tegra_data * tspi,struct spi_transfer * t)202 static unsigned spi_tegra_fill_tx_fifo(struct spi_tegra_data *tspi,
203 				  struct spi_transfer *t)
204 {
205 	unsigned len = min(t->len - tspi->cur_pos, BB_LEN *
206 			   tspi->cur_bytes_per_word);
207 	u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_pos;
208 	int i, j;
209 	unsigned long val;
210 
211 	val = spi_tegra_readl(tspi, SLINK_COMMAND);
212 	val &= ~SLINK_WORD_SIZE(~0);
213 	val |= SLINK_WORD_SIZE(len / tspi->cur_bytes_per_word - 1);
214 	spi_tegra_writel(tspi, val, SLINK_COMMAND);
215 
216 	for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
217 		val = 0;
218 		for (j = 0; j < tspi->cur_bytes_per_word; j++)
219 			val |= tx_buf[i + j] << j * 8;
220 
221 		spi_tegra_writel(tspi, val, SLINK_TX_FIFO);
222 	}
223 
224 	tspi->rx_dma_req.size = len / tspi->cur_bytes_per_word * 4;
225 
226 	return len;
227 }
228 
spi_tegra_drain_rx_fifo(struct spi_tegra_data * tspi,struct spi_transfer * t)229 static unsigned spi_tegra_drain_rx_fifo(struct spi_tegra_data *tspi,
230 				  struct spi_transfer *t)
231 {
232 	unsigned len = tspi->cur_len;
233 	u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_pos;
234 	int i, j;
235 	unsigned long val;
236 
237 	for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
238 		val = tspi->rx_bb[i / tspi->cur_bytes_per_word];
239 		for (j = 0; j < tspi->cur_bytes_per_word; j++)
240 			rx_buf[i + j] = (val >> (j * 8)) & 0xff;
241 	}
242 
243 	return len;
244 }
245 
spi_tegra_start_transfer(struct spi_device * spi,struct spi_transfer * t)246 static void spi_tegra_start_transfer(struct spi_device *spi,
247 				    struct spi_transfer *t)
248 {
249 	struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
250 	u32 speed;
251 	u8 bits_per_word;
252 	unsigned long val;
253 
254 	speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
255 	bits_per_word = t->bits_per_word ? t->bits_per_word  :
256 		spi->bits_per_word;
257 
258 	tspi->cur_bytes_per_word = (bits_per_word - 1) / 8 + 1;
259 
260 	if (speed != tspi->cur_speed)
261 		clk_set_rate(tspi->clk, speed);
262 
263 	if (tspi->cur_speed == 0)
264 		clk_enable(tspi->clk);
265 
266 	tspi->cur_speed = speed;
267 
268 	val = spi_tegra_readl(tspi, SLINK_COMMAND2);
269 	val &= ~SLINK_SS_EN_CS(~0) | SLINK_RXEN | SLINK_TXEN;
270 	if (t->rx_buf)
271 		val |= SLINK_RXEN;
272 	if (t->tx_buf)
273 		val |= SLINK_TXEN;
274 	val |= SLINK_SS_EN_CS(spi->chip_select);
275 	val |= SLINK_SPIE;
276 	spi_tegra_writel(tspi, val, SLINK_COMMAND2);
277 
278 	val = spi_tegra_readl(tspi, SLINK_COMMAND);
279 	val &= ~SLINK_BIT_LENGTH(~0);
280 	val |= SLINK_BIT_LENGTH(bits_per_word - 1);
281 
282 	/* FIXME: should probably control CS manually so that we can be sure
283 	 * it does not go low between transfer and to support delay_usecs
284 	 * correctly.
285 	 */
286 	val &= ~SLINK_IDLE_SCLK_MASK & ~SLINK_CK_SDA & ~SLINK_CS_SW;
287 
288 	if (spi->mode & SPI_CPHA)
289 		val |= SLINK_CK_SDA;
290 
291 	if (spi->mode & SPI_CPOL)
292 		val |= SLINK_IDLE_SCLK_DRIVE_HIGH;
293 	else
294 		val |= SLINK_IDLE_SCLK_DRIVE_LOW;
295 
296 	val |= SLINK_M_S;
297 
298 	spi_tegra_writel(tspi, val, SLINK_COMMAND);
299 
300 	spi_tegra_writel(tspi, SLINK_RX_FLUSH | SLINK_TX_FLUSH, SLINK_STATUS);
301 
302 	tspi->cur = t;
303 	tspi->cur_pos = 0;
304 	tspi->cur_len = spi_tegra_fill_tx_fifo(tspi, t);
305 
306 	spi_tegra_go(tspi);
307 }
308 
spi_tegra_start_message(struct spi_device * spi,struct spi_message * m)309 static void spi_tegra_start_message(struct spi_device *spi,
310 				    struct spi_message *m)
311 {
312 	struct spi_transfer *t;
313 
314 	m->actual_length = 0;
315 	m->status = 0;
316 
317 	t = list_first_entry(&m->transfers, struct spi_transfer, transfer_list);
318 	spi_tegra_start_transfer(spi, t);
319 }
320 
tegra_spi_rx_dma_complete(struct tegra_dma_req * req)321 static void tegra_spi_rx_dma_complete(struct tegra_dma_req *req)
322 {
323 	struct spi_tegra_data *tspi = req->dev;
324 	unsigned long flags;
325 	struct spi_message *m;
326 	struct spi_device *spi;
327 	int timeout = 0;
328 	unsigned long val;
329 
330 	/* the SPI controller may come back with both the BSY and RDY bits
331 	 * set.  In this case we need to wait for the BSY bit to clear so
332 	 * that we are sure the DMA is finished.  1000 reads was empirically
333 	 * determined to be long enough.
334 	 */
335 	while (timeout++ < 1000) {
336 		if (!(spi_tegra_readl(tspi, SLINK_STATUS) & SLINK_BSY))
337 			break;
338 	}
339 
340 	spin_lock_irqsave(&tspi->lock, flags);
341 
342 	val = spi_tegra_readl(tspi, SLINK_STATUS);
343 	val |= SLINK_RDY;
344 	spi_tegra_writel(tspi, val, SLINK_STATUS);
345 
346 	m = list_first_entry(&tspi->queue, struct spi_message, queue);
347 
348 	if (timeout >= 1000)
349 		m->status = -EIO;
350 
351 	spi = m->state;
352 
353 	tspi->cur_pos += spi_tegra_drain_rx_fifo(tspi, tspi->cur);
354 	m->actual_length += tspi->cur_pos;
355 
356 	if (tspi->cur_pos < tspi->cur->len) {
357 		tspi->cur_len = spi_tegra_fill_tx_fifo(tspi, tspi->cur);
358 		spi_tegra_go(tspi);
359 	} else if (!list_is_last(&tspi->cur->transfer_list,
360 				 &m->transfers)) {
361 		tspi->cur =  list_first_entry(&tspi->cur->transfer_list,
362 					      struct spi_transfer,
363 					      transfer_list);
364 		spi_tegra_start_transfer(spi, tspi->cur);
365 	} else {
366 		list_del(&m->queue);
367 
368 		m->complete(m->context);
369 
370 		if (!list_empty(&tspi->queue)) {
371 			m = list_first_entry(&tspi->queue, struct spi_message,
372 					     queue);
373 			spi = m->state;
374 			spi_tegra_start_message(spi, m);
375 		} else {
376 			clk_disable(tspi->clk);
377 			tspi->cur_speed = 0;
378 		}
379 	}
380 
381 	spin_unlock_irqrestore(&tspi->lock, flags);
382 }
383 
spi_tegra_setup(struct spi_device * spi)384 static int spi_tegra_setup(struct spi_device *spi)
385 {
386 	struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
387 	unsigned long cs_bit;
388 	unsigned long val;
389 	unsigned long flags;
390 
391 	dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
392 		spi->bits_per_word,
393 		spi->mode & SPI_CPOL ? "" : "~",
394 		spi->mode & SPI_CPHA ? "" : "~",
395 		spi->max_speed_hz);
396 
397 
398 	switch (spi->chip_select) {
399 	case 0:
400 		cs_bit = SLINK_CS_POLARITY;
401 		break;
402 
403 	case 1:
404 		cs_bit = SLINK_CS_POLARITY1;
405 		break;
406 
407 	case 2:
408 		cs_bit = SLINK_CS_POLARITY2;
409 		break;
410 
411 	case 4:
412 		cs_bit = SLINK_CS_POLARITY3;
413 		break;
414 
415 	default:
416 		return -EINVAL;
417 	}
418 
419 	spin_lock_irqsave(&tspi->lock, flags);
420 
421 	val = spi_tegra_readl(tspi, SLINK_COMMAND);
422 	if (spi->mode & SPI_CS_HIGH)
423 		val |= cs_bit;
424 	else
425 		val &= ~cs_bit;
426 	spi_tegra_writel(tspi, val, SLINK_COMMAND);
427 
428 	spin_unlock_irqrestore(&tspi->lock, flags);
429 
430 	return 0;
431 }
432 
spi_tegra_transfer(struct spi_device * spi,struct spi_message * m)433 static int spi_tegra_transfer(struct spi_device *spi, struct spi_message *m)
434 {
435 	struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
436 	struct spi_transfer *t;
437 	unsigned long flags;
438 	int was_empty;
439 
440 	if (list_empty(&m->transfers) || !m->complete)
441 		return -EINVAL;
442 
443 	list_for_each_entry(t, &m->transfers, transfer_list) {
444 		if (t->bits_per_word < 0 || t->bits_per_word > 32)
445 			return -EINVAL;
446 
447 		if (t->len == 0)
448 			return -EINVAL;
449 
450 		if (!t->rx_buf && !t->tx_buf)
451 			return -EINVAL;
452 	}
453 
454 	m->state = spi;
455 
456 	spin_lock_irqsave(&tspi->lock, flags);
457 	was_empty = list_empty(&tspi->queue);
458 	list_add_tail(&m->queue, &tspi->queue);
459 
460 	if (was_empty)
461 		spi_tegra_start_message(spi, m);
462 
463 	spin_unlock_irqrestore(&tspi->lock, flags);
464 
465 	return 0;
466 }
467 
spi_tegra_probe(struct platform_device * pdev)468 static int __devinit spi_tegra_probe(struct platform_device *pdev)
469 {
470 	struct spi_master	*master;
471 	struct spi_tegra_data	*tspi;
472 	struct resource		*r;
473 	int ret;
474 
475 	master = spi_alloc_master(&pdev->dev, sizeof *tspi);
476 	if (master == NULL) {
477 		dev_err(&pdev->dev, "master allocation failed\n");
478 		return -ENOMEM;
479 	}
480 
481 	/* the spi->mode bits understood by this driver: */
482 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
483 
484 	master->bus_num = pdev->id;
485 
486 	master->setup = spi_tegra_setup;
487 	master->transfer = spi_tegra_transfer;
488 	master->num_chipselect = 4;
489 
490 	dev_set_drvdata(&pdev->dev, master);
491 	tspi = spi_master_get_devdata(master);
492 	tspi->master = master;
493 	tspi->pdev = pdev;
494 	spin_lock_init(&tspi->lock);
495 
496 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
497 	if (r == NULL) {
498 		ret = -ENODEV;
499 		goto err0;
500 	}
501 
502 	if (!request_mem_region(r->start, resource_size(r),
503 				dev_name(&pdev->dev))) {
504 		ret = -EBUSY;
505 		goto err0;
506 	}
507 
508 	tspi->phys = r->start;
509 	tspi->base = ioremap(r->start, resource_size(r));
510 	if (!tspi->base) {
511 		dev_err(&pdev->dev, "can't ioremap iomem\n");
512 		ret = -ENOMEM;
513 		goto err1;
514 	}
515 
516 	tspi->clk = clk_get(&pdev->dev, NULL);
517 	if (IS_ERR(tspi->clk)) {
518 		dev_err(&pdev->dev, "can not get clock\n");
519 		ret = PTR_ERR(tspi->clk);
520 		goto err2;
521 	}
522 
523 	INIT_LIST_HEAD(&tspi->queue);
524 
525 	tspi->rx_dma = tegra_dma_allocate_channel(TEGRA_DMA_MODE_ONESHOT);
526 	if (!tspi->rx_dma) {
527 		dev_err(&pdev->dev, "can not allocate rx dma channel\n");
528 		ret = -ENODEV;
529 		goto err3;
530 	}
531 
532 	tspi->rx_bb = dma_alloc_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
533 					 &tspi->rx_bb_phys, GFP_KERNEL);
534 	if (!tspi->rx_bb) {
535 		dev_err(&pdev->dev, "can not allocate rx bounce buffer\n");
536 		ret = -ENOMEM;
537 		goto err4;
538 	}
539 
540 	tspi->rx_dma_req.complete = tegra_spi_rx_dma_complete;
541 	tspi->rx_dma_req.to_memory = 1;
542 	tspi->rx_dma_req.dest_addr = tspi->rx_bb_phys;
543 	tspi->rx_dma_req.dest_bus_width = 32;
544 	tspi->rx_dma_req.source_addr = tspi->phys + SLINK_RX_FIFO;
545 	tspi->rx_dma_req.source_bus_width = 32;
546 	tspi->rx_dma_req.source_wrap = 4;
547 	tspi->rx_dma_req.req_sel = spi_tegra_req_sels[pdev->id];
548 	tspi->rx_dma_req.dev = tspi;
549 
550 	master->dev.of_node = pdev->dev.of_node;
551 	ret = spi_register_master(master);
552 
553 	if (ret < 0)
554 		goto err5;
555 
556 	return ret;
557 
558 err5:
559 	dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
560 			  tspi->rx_bb, tspi->rx_bb_phys);
561 err4:
562 	tegra_dma_free_channel(tspi->rx_dma);
563 err3:
564 	clk_put(tspi->clk);
565 err2:
566 	iounmap(tspi->base);
567 err1:
568 	release_mem_region(r->start, resource_size(r));
569 err0:
570 	spi_master_put(master);
571 	return ret;
572 }
573 
spi_tegra_remove(struct platform_device * pdev)574 static int __devexit spi_tegra_remove(struct platform_device *pdev)
575 {
576 	struct spi_master	*master;
577 	struct spi_tegra_data	*tspi;
578 	struct resource		*r;
579 
580 	master = dev_get_drvdata(&pdev->dev);
581 	tspi = spi_master_get_devdata(master);
582 
583 	spi_unregister_master(master);
584 	tegra_dma_free_channel(tspi->rx_dma);
585 
586 	dma_free_coherent(&pdev->dev, sizeof(u32) * BB_LEN,
587 			  tspi->rx_bb, tspi->rx_bb_phys);
588 
589 	clk_put(tspi->clk);
590 	iounmap(tspi->base);
591 
592 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
593 	release_mem_region(r->start, resource_size(r));
594 
595 	return 0;
596 }
597 
598 MODULE_ALIAS("platform:spi_tegra");
599 
600 #ifdef CONFIG_OF
601 static struct of_device_id spi_tegra_of_match_table[] __devinitdata = {
602 	{ .compatible = "nvidia,tegra20-spi", },
603 	{}
604 };
605 MODULE_DEVICE_TABLE(of, spi_tegra_of_match_table);
606 #else /* CONFIG_OF */
607 #define spi_tegra_of_match_table NULL
608 #endif /* CONFIG_OF */
609 
610 static struct platform_driver spi_tegra_driver = {
611 	.driver = {
612 		.name =		"spi_tegra",
613 		.owner =	THIS_MODULE,
614 		.of_match_table = spi_tegra_of_match_table,
615 	},
616 	.probe =	spi_tegra_probe,
617 	.remove =	__devexit_p(spi_tegra_remove),
618 };
619 module_platform_driver(spi_tegra_driver);
620 
621 MODULE_LICENSE("GPL");
622