?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Avoid beyond bounds copy while caching ACL
[zen-stable.git] / drivers / spi / spi-sh.c
blob70c8af9f7cccbc7ad9c01d9202f2b34af7b976ed
1 /*
2 * SH SPI bus driver
3 *
4 * Copyright (C) 2011 Renesas Solutions Corp.
5 *
6 * Based on pxa2xx_spi.c:
7 * Copyright (C) 2005 Stephen Street / StreetFire Sound Labs
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; version 2 of the License.
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 *
22 */
23
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/sched.h>
27 #include <linux/errno.h>
28 #include <linux/timer.h>
29 #include <linux/delay.h>
30 #include <linux/list.h>
31 #include <linux/workqueue.h>
32 #include <linux/interrupt.h>
33 #include <linux/platform_device.h>
34 #include <linux/io.h>
35 #include <linux/spi/spi.h>
36
37 #define SPI_SH_TBR 0x00
38 #define SPI_SH_RBR 0x00
39 #define SPI_SH_CR1 0x08
40 #define SPI_SH_CR2 0x10
41 #define SPI_SH_CR3 0x18
42 #define SPI_SH_CR4 0x20
43 #define SPI_SH_CR5 0x28
44
45 /* CR1 */
46 #define SPI_SH_TBE 0x80
47 #define SPI_SH_TBF 0x40
48 #define SPI_SH_RBE 0x20
49 #define SPI_SH_RBF 0x10
50 #define SPI_SH_PFONRD 0x08
51 #define SPI_SH_SSDB 0x04
52 #define SPI_SH_SSD 0x02
53 #define SPI_SH_SSA 0x01
54
55 /* CR2 */
56 #define SPI_SH_RSTF 0x80
57 #define SPI_SH_LOOPBK 0x40
58 #define SPI_SH_CPOL 0x20
59 #define SPI_SH_CPHA 0x10
60 #define SPI_SH_L1M0 0x08
61
62 /* CR3 */
63 #define SPI_SH_MAX_BYTE 0xFF
64
65 /* CR4 */
66 #define SPI_SH_TBEI 0x80
67 #define SPI_SH_TBFI 0x40
68 #define SPI_SH_RBEI 0x20
69 #define SPI_SH_RBFI 0x10
70 #define SPI_SH_WPABRT 0x04
71 #define SPI_SH_SSS 0x01
72
73 /* CR8 */
74 #define SPI_SH_P1L0 0x80
75 #define SPI_SH_PP1L0 0x40
76 #define SPI_SH_MUXI 0x20
77 #define SPI_SH_MUXIRQ 0x10
78
79 #define SPI_SH_FIFO_SIZE 32
80 #define SPI_SH_SEND_TIMEOUT (3 * HZ)
81 #define SPI_SH_RECEIVE_TIMEOUT (HZ >> 3)
82
83 #undef DEBUG
84
85 struct spi_sh_data {
86 void __iomem *addr;
87 int irq;
88 struct spi_master *master;
89 struct list_head queue;
90 struct workqueue_struct *workqueue;
91 struct work_struct ws;
92 unsigned long cr1;
93 wait_queue_head_t wait;
94 spinlock_t lock;
95 };
96
97 static void spi_sh_write(struct spi_sh_data *ss, unsigned long data,
98 unsigned long offset)
99 {
100 writel(data, ss->addr + offset);
101 }
102
103 static unsigned long spi_sh_read(struct spi_sh_data *ss, unsigned long offset)
104 {
105 return readl(ss->addr + offset);
106 }
107
108 static void spi_sh_set_bit(struct spi_sh_data *ss, unsigned long val,
109 unsigned long offset)
110 {
111 unsigned long tmp;
112
113 tmp = spi_sh_read(ss, offset);
114 tmp |= val;
115 spi_sh_write(ss, tmp, offset);
116 }
117
118 static void spi_sh_clear_bit(struct spi_sh_data *ss, unsigned long val,
119 unsigned long offset)
120 {
121 unsigned long tmp;
122
123 tmp = spi_sh_read(ss, offset);
124 tmp &= ~val;
125 spi_sh_write(ss, tmp, offset);
126 }
127
128 static void clear_fifo(struct spi_sh_data *ss)
129 {
130 spi_sh_set_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
131 spi_sh_clear_bit(ss, SPI_SH_RSTF, SPI_SH_CR2);
132 }
133
134 static int spi_sh_wait_receive_buffer(struct spi_sh_data *ss)
135 {
136 int timeout = 100000;
137
138 while (spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
139 udelay(10);
140 if (timeout-- < 0)
141 return -ETIMEDOUT;
142 }
143 return 0;
144 }
145
146 static int spi_sh_wait_write_buffer_empty(struct spi_sh_data *ss)
147 {
148 int timeout = 100000;
149
150 while (!(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBE)) {
151 udelay(10);
152 if (timeout-- < 0)
153 return -ETIMEDOUT;
154 }
155 return 0;
156 }
157
158 static int spi_sh_send(struct spi_sh_data *ss, struct spi_message *mesg,
159 struct spi_transfer *t)
160 {
161 int i, retval = 0;
162 int remain = t->len;
163 int cur_len;
164 unsigned char *data;
165 unsigned long tmp;
166 long ret;
167
168 if (t->len)
169 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
170
171 data = (unsigned char *)t->tx_buf;
172 while (remain > 0) {
173 cur_len = min(SPI_SH_FIFO_SIZE, remain);
174 for (i = 0; i < cur_len &&
175 !(spi_sh_read(ss, SPI_SH_CR4) &
176 SPI_SH_WPABRT) &&
177 !(spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_TBF);
178 i++)
179 spi_sh_write(ss, (unsigned long)data[i], SPI_SH_TBR);
180
181 if (spi_sh_read(ss, SPI_SH_CR4) & SPI_SH_WPABRT) {
182 /* Abort SPI operation */
183 spi_sh_set_bit(ss, SPI_SH_WPABRT, SPI_SH_CR4);
184 retval = -EIO;
185 break;
186 }
187
188 cur_len = i;
189
190 remain -= cur_len;
191 data += cur_len;
192
193 if (remain > 0) {
194 ss->cr1 &= ~SPI_SH_TBE;
195 spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
196 ret = wait_event_interruptible_timeout(ss->wait,
197 ss->cr1 & SPI_SH_TBE,
198 SPI_SH_SEND_TIMEOUT);
199 if (ret == 0 && !(ss->cr1 & SPI_SH_TBE)) {
200 printk(KERN_ERR "%s: timeout\n", __func__);
201 return -ETIMEDOUT;
202 }
203 }
204 }
205
206 if (list_is_last(&t->transfer_list, &mesg->transfers)) {
207 tmp = spi_sh_read(ss, SPI_SH_CR1);
208 tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
209 spi_sh_write(ss, tmp, SPI_SH_CR1);
210 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
211
212 ss->cr1 &= ~SPI_SH_TBE;
213 spi_sh_set_bit(ss, SPI_SH_TBE, SPI_SH_CR4);
214 ret = wait_event_interruptible_timeout(ss->wait,
215 ss->cr1 & SPI_SH_TBE,
216 SPI_SH_SEND_TIMEOUT);
217 if (ret == 0 && (ss->cr1 & SPI_SH_TBE)) {
218 printk(KERN_ERR "%s: timeout\n", __func__);
219 return -ETIMEDOUT;
220 }
221 }
222
223 return retval;
224 }
225
226 static int spi_sh_receive(struct spi_sh_data *ss, struct spi_message *mesg,
227 struct spi_transfer *t)
228 {
229 int i;
230 int remain = t->len;
231 int cur_len;
232 unsigned char *data;
233 unsigned long tmp;
234 long ret;
235
236 if (t->len > SPI_SH_MAX_BYTE)
237 spi_sh_write(ss, SPI_SH_MAX_BYTE, SPI_SH_CR3);
238 else
239 spi_sh_write(ss, t->len, SPI_SH_CR3);
240
241 tmp = spi_sh_read(ss, SPI_SH_CR1);
242 tmp = tmp & ~(SPI_SH_SSD | SPI_SH_SSDB);
243 spi_sh_write(ss, tmp, SPI_SH_CR1);
244 spi_sh_set_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
245
246 spi_sh_wait_write_buffer_empty(ss);
247
248 data = (unsigned char *)t->rx_buf;
249 while (remain > 0) {
250 if (remain >= SPI_SH_FIFO_SIZE) {
251 ss->cr1 &= ~SPI_SH_RBF;
252 spi_sh_set_bit(ss, SPI_SH_RBF, SPI_SH_CR4);
253 ret = wait_event_interruptible_timeout(ss->wait,
254 ss->cr1 & SPI_SH_RBF,
255 SPI_SH_RECEIVE_TIMEOUT);
256 if (ret == 0 &&
257 spi_sh_read(ss, SPI_SH_CR1) & SPI_SH_RBE) {
258 printk(KERN_ERR "%s: timeout\n", __func__);
259 return -ETIMEDOUT;
260 }
261 }
262
263 cur_len = min(SPI_SH_FIFO_SIZE, remain);
264 for (i = 0; i < cur_len; i++) {
265 if (spi_sh_wait_receive_buffer(ss))
266 break;
267 data[i] = (unsigned char)spi_sh_read(ss, SPI_SH_RBR);
268 }
269
270 remain -= cur_len;
271 data += cur_len;
272 }
273
274 /* deassert CS when SPI is receiving. */
275 if (t->len > SPI_SH_MAX_BYTE) {
276 clear_fifo(ss);
277 spi_sh_write(ss, 1, SPI_SH_CR3);
278 } else {
279 spi_sh_write(ss, 0, SPI_SH_CR3);
280 }
281
282 return 0;
283 }
284
285 static void spi_sh_work(struct work_struct *work)
286 {
287 struct spi_sh_data *ss = container_of(work, struct spi_sh_data, ws);
288 struct spi_message *mesg;
289 struct spi_transfer *t;
290 unsigned long flags;
291 int ret;
292
293 pr_debug("%s: enter\n", __func__);
294
295 spin_lock_irqsave(&ss->lock, flags);
296 while (!list_empty(&ss->queue)) {
297 mesg = list_entry(ss->queue.next, struct spi_message, queue);
298 list_del_init(&mesg->queue);
299
300 spin_unlock_irqrestore(&ss->lock, flags);
301 list_for_each_entry(t, &mesg->transfers, transfer_list) {
302 pr_debug("tx_buf = %p, rx_buf = %p\n",
303 t->tx_buf, t->rx_buf);
304 pr_debug("len = %d, delay_usecs = %d\n",
305 t->len, t->delay_usecs);
306
307 if (t->tx_buf) {
308 ret = spi_sh_send(ss, mesg, t);
309 if (ret < 0)
310 goto error;
311 }
312 if (t->rx_buf) {
313 ret = spi_sh_receive(ss, mesg, t);
314 if (ret < 0)
315 goto error;
316 }
317 mesg->actual_length += t->len;
318 }
319 spin_lock_irqsave(&ss->lock, flags);
320
321 mesg->status = 0;
322 mesg->complete(mesg->context);
323 }
324
325 clear_fifo(ss);
326 spi_sh_set_bit(ss, SPI_SH_SSD, SPI_SH_CR1);
327 udelay(100);
328
329 spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
330 SPI_SH_CR1);
331
332 clear_fifo(ss);
333
334 spin_unlock_irqrestore(&ss->lock, flags);
335
336 return;
337
338 error:
339 mesg->status = ret;
340 mesg->complete(mesg->context);
341
342 spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
343 SPI_SH_CR1);
344 clear_fifo(ss);
345
346 }
347
348 static int spi_sh_setup(struct spi_device *spi)
349 {
350 struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
351
352 if (!spi->bits_per_word)
353 spi->bits_per_word = 8;
354
355 pr_debug("%s: enter\n", __func__);
356
357 spi_sh_write(ss, 0xfe, SPI_SH_CR1); /* SPI sycle stop */
358 spi_sh_write(ss, 0x00, SPI_SH_CR1); /* CR1 init */
359 spi_sh_write(ss, 0x00, SPI_SH_CR3); /* CR3 init */
360
361 clear_fifo(ss);
362
363 /* 1/8 clock */
364 spi_sh_write(ss, spi_sh_read(ss, SPI_SH_CR2) | 0x07, SPI_SH_CR2);
365 udelay(10);
366
367 return 0;
368 }
369
370 static int spi_sh_transfer(struct spi_device *spi, struct spi_message *mesg)
371 {
372 struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
373 unsigned long flags;
374
375 pr_debug("%s: enter\n", __func__);
376 pr_debug("\tmode = %02x\n", spi->mode);
377
378 spin_lock_irqsave(&ss->lock, flags);
379
380 mesg->actual_length = 0;
381 mesg->status = -EINPROGRESS;
382
383 spi_sh_clear_bit(ss, SPI_SH_SSA, SPI_SH_CR1);
384
385 list_add_tail(&mesg->queue, &ss->queue);
386 queue_work(ss->workqueue, &ss->ws);
387
388 spin_unlock_irqrestore(&ss->lock, flags);
389
390 return 0;
391 }
392
393 static void spi_sh_cleanup(struct spi_device *spi)
394 {
395 struct spi_sh_data *ss = spi_master_get_devdata(spi->master);
396
397 pr_debug("%s: enter\n", __func__);
398
399 spi_sh_clear_bit(ss, SPI_SH_SSA | SPI_SH_SSDB | SPI_SH_SSD,
400 SPI_SH_CR1);
401 }
402
403 static irqreturn_t spi_sh_irq(int irq, void *_ss)
404 {
405 struct spi_sh_data *ss = (struct spi_sh_data *)_ss;
406 unsigned long cr1;
407
408 cr1 = spi_sh_read(ss, SPI_SH_CR1);
409 if (cr1 & SPI_SH_TBE)
410 ss->cr1 |= SPI_SH_TBE;
411 if (cr1 & SPI_SH_TBF)
412 ss->cr1 |= SPI_SH_TBF;
413 if (cr1 & SPI_SH_RBE)
414 ss->cr1 |= SPI_SH_RBE;
415 if (cr1 & SPI_SH_RBF)
416 ss->cr1 |= SPI_SH_RBF;
417
418 if (ss->cr1) {
419 spi_sh_clear_bit(ss, ss->cr1, SPI_SH_CR4);
420 wake_up(&ss->wait);
421 }
422
423 return IRQ_HANDLED;
424 }
425
426 static int __devexit spi_sh_remove(struct platform_device *pdev)
427 {
428 struct spi_sh_data *ss = dev_get_drvdata(&pdev->dev);
429
430 spi_unregister_master(ss->master);
431 destroy_workqueue(ss->workqueue);
432 free_irq(ss->irq, ss);
433 iounmap(ss->addr);
434
435 return 0;
436 }
437
438 static int __devinit spi_sh_probe(struct platform_device *pdev)
439 {
440 struct resource *res;
441 struct spi_master *master;
442 struct spi_sh_data *ss;
443 int ret, irq;
444
445 /* get base addr */
446 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
447 if (unlikely(res == NULL)) {
448 dev_err(&pdev->dev, "invalid resource\n");
449 return -EINVAL;
450 }
451
452 irq = platform_get_irq(pdev, 0);
453 if (irq < 0) {
454 dev_err(&pdev->dev, "platform_get_irq error\n");
455 return -ENODEV;
456 }
457
458 master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
459 if (master == NULL) {
460 dev_err(&pdev->dev, "spi_alloc_master error.\n");
461 return -ENOMEM;
462 }
463
464 ss = spi_master_get_devdata(master);
465 dev_set_drvdata(&pdev->dev, ss);
466
467 ss->irq = irq;
468 ss->master = master;
469 ss->addr = ioremap(res->start, resource_size(res));
470 if (ss->addr == NULL) {
471 dev_err(&pdev->dev, "ioremap error.\n");
472 ret = -ENOMEM;
473 goto error1;
474 }
475 INIT_LIST_HEAD(&ss->queue);
476 spin_lock_init(&ss->lock);
477 INIT_WORK(&ss->ws, spi_sh_work);
478 init_waitqueue_head(&ss->wait);
479 ss->workqueue = create_singlethread_workqueue(
480 dev_name(master->dev.parent));
481 if (ss->workqueue == NULL) {
482 dev_err(&pdev->dev, "create workqueue error\n");
483 ret = -EBUSY;
484 goto error2;
485 }
486
487 ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
488 if (ret < 0) {
489 dev_err(&pdev->dev, "request_irq error\n");
490 goto error3;
491 }
492
493 master->num_chipselect = 2;
494 master->bus_num = pdev->id;
495 master->setup = spi_sh_setup;
496 master->transfer = spi_sh_transfer;
497 master->cleanup = spi_sh_cleanup;
498
499 ret = spi_register_master(master);
500 if (ret < 0) {
501 printk(KERN_ERR "spi_register_master error.\n");
502 goto error4;
503 }
504
505 return 0;
506
507 error4:
508 free_irq(irq, ss);
509 error3:
510 destroy_workqueue(ss->workqueue);
511 error2:
512 iounmap(ss->addr);
513 error1:
514 spi_master_put(master);
515
516 return ret;
517 }
518
519 static struct platform_driver spi_sh_driver = {
520 .probe = spi_sh_probe,
521 .remove = __devexit_p(spi_sh_remove),
522 .driver = {
523 .name = "sh_spi",
524 .owner = THIS_MODULE,
525 },
526 };
527 module_platform_driver(spi_sh_driver);
528
529 MODULE_DESCRIPTION("SH SPI bus driver");
530 MODULE_LICENSE("GPL");
531 MODULE_AUTHOR("Yoshihiro Shimoda");
532 MODULE_ALIAS("platform:sh_spi");