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29#include <linux/init.h>
30#include <linux/module.h>
31#include <linux/device.h>
32#include <linux/interrupt.h>
33#include <linux/spinlock.h>
34#include <linux/errno.h>
35#include <linux/io.h>
36#include <linux/irq.h>
37#include <linux/platform_device.h>
38#include <linux/debugfs.h>
39#include <linux/seq_file.h>
40#include <linux/completion.h>
41#include <mach/mbox-db5500.h>
42
43#define MBOX_NAME "mbox"
44
45#define MBOX_FIFO_DATA 0x000
46#define MBOX_FIFO_ADD 0x004
47#define MBOX_FIFO_REMOVE 0x008
48#define MBOX_FIFO_THRES_FREE 0x00C
49#define MBOX_FIFO_THRES_OCCUP 0x010
50#define MBOX_FIFO_STATUS 0x014
51
52#define MBOX_DISABLE_IRQ 0x4
53#define MBOX_ENABLE_IRQ 0x0
54#define MBOX_LATCH 1
55
56
57static struct list_head mboxs = LIST_HEAD_INIT(mboxs);
58
59static struct mbox *get_mbox_with_id(u8 id)
60{
61 u8 i;
62 struct list_head *pos = &mboxs;
63 for (i = 0; i <= id; i++)
64 pos = pos->next;
65
66 return (struct mbox *) list_entry(pos, struct mbox, list);
67}
68
69int mbox_send(struct mbox *mbox, u32 mbox_msg, bool block)
70{
71 int res = 0;
72
73 spin_lock(&mbox->lock);
74
75 dev_dbg(&(mbox->pdev->dev),
76 "About to buffer 0x%X to mailbox 0x%X."
77 " ri = %d, wi = %d\n",
78 mbox_msg, (u32)mbox, mbox->read_index,
79 mbox->write_index);
80
81
82 while (((mbox->write_index + 1) % MBOX_BUF_SIZE) == mbox->read_index) {
83 if (!block) {
84 dev_dbg(&(mbox->pdev->dev),
85 "Buffer full in non-blocking call! "
86 "Returning -ENOMEM!\n");
87 res = -ENOMEM;
88 goto exit;
89 }
90 spin_unlock(&mbox->lock);
91 dev_dbg(&(mbox->pdev->dev),
92 "Buffer full in blocking call! Sleeping...\n");
93 mbox->client_blocked = 1;
94 wait_for_completion(&mbox->buffer_available);
95 dev_dbg(&(mbox->pdev->dev),
96 "Blocking send was woken up! Trying again...\n");
97 spin_lock(&mbox->lock);
98 }
99
100 mbox->buffer[mbox->write_index] = mbox_msg;
101 mbox->write_index = (mbox->write_index + 1) % MBOX_BUF_SIZE;
102
103
104
105
106
107 writel(MBOX_ENABLE_IRQ, mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
108
109exit:
110 spin_unlock(&mbox->lock);
111 return res;
112}
113EXPORT_SYMBOL(mbox_send);
114
115#if defined(CONFIG_DEBUG_FS)
116
117
118
119
120static ssize_t mbox_write_fifo(struct device *dev,
121 struct device_attribute *attr,
122 const char *buf,
123 size_t count)
124{
125 unsigned long mbox_mess;
126 unsigned long nbr_sends;
127 unsigned long i;
128 char int_buf[16];
129 char *token;
130 char *val;
131
132 struct mbox *mbox = (struct mbox *) dev->platform_data;
133
134 strncpy((char *) &int_buf, buf, sizeof(int_buf));
135 token = (char *) &int_buf;
136
137
138 val = strsep(&token, " ");
139 if ((val == NULL) || (strict_strtoul(val, 16, &mbox_mess) != 0))
140 mbox_mess = 0xDEADBEEF;
141
142 val = strsep(&token, " ");
143 if ((val == NULL) || (strict_strtoul(val, 10, &nbr_sends) != 0))
144 nbr_sends = 1;
145
146 dev_dbg(dev, "Will write 0x%lX %ld times using data struct at 0x%X\n",
147 mbox_mess, nbr_sends, (u32) mbox);
148
149 for (i = 0; i < nbr_sends; i++)
150 mbox_send(mbox, mbox_mess, true);
151
152 return count;
153}
154
155static ssize_t mbox_read_fifo(struct device *dev,
156 struct device_attribute *attr,
157 char *buf)
158{
159 int mbox_value;
160 struct mbox *mbox = (struct mbox *) dev->platform_data;
161
162 if ((readl(mbox->virtbase_local + MBOX_FIFO_STATUS) & 0x7) <= 0)
163 return sprintf(buf, "Mailbox is empty\n");
164
165 mbox_value = readl(mbox->virtbase_local + MBOX_FIFO_DATA);
166 writel(MBOX_LATCH, (mbox->virtbase_local + MBOX_FIFO_REMOVE));
167
168 return sprintf(buf, "0x%X\n", mbox_value);
169}
170
171static DEVICE_ATTR(fifo, S_IWUGO | S_IRUGO, mbox_read_fifo, mbox_write_fifo);
172
173static int mbox_show(struct seq_file *s, void *data)
174{
175 struct list_head *pos;
176 u8 mbox_index = 0;
177
178 list_for_each(pos, &mboxs) {
179 struct mbox *m =
180 (struct mbox *) list_entry(pos, struct mbox, list);
181 if (m == NULL) {
182 seq_printf(s,
183 "Unable to retrieve mailbox %d\n",
184 mbox_index);
185 continue;
186 }
187
188 spin_lock(&m->lock);
189 if ((m->virtbase_peer == NULL) || (m->virtbase_local == NULL)) {
190 seq_printf(s, "MAILBOX %d not setup or corrupt\n",
191 mbox_index);
192 spin_unlock(&m->lock);
193 continue;
194 }
195
196 seq_printf(s,
197 "===========================\n"
198 " MAILBOX %d\n"
199 " PEER MAILBOX DUMP\n"
200 "---------------------------\n"
201 "FIFO: 0x%X (%d)\n"
202 "Free Threshold: 0x%.2X (%d)\n"
203 "Occupied Threshold: 0x%.2X (%d)\n"
204 "Status: 0x%.2X (%d)\n"
205 " Free spaces (ot): %d (%d)\n"
206 " Occup spaces (ot): %d (%d)\n"
207 "===========================\n"
208 " LOCAL MAILBOX DUMP\n"
209 "---------------------------\n"
210 "FIFO: 0x%.X (%d)\n"
211 "Free Threshold: 0x%.2X (%d)\n"
212 "Occupied Threshold: 0x%.2X (%d)\n"
213 "Status: 0x%.2X (%d)\n"
214 " Free spaces (ot): %d (%d)\n"
215 " Occup spaces (ot): %d (%d)\n"
216 "===========================\n"
217 "write_index: %d\n"
218 "read_index : %d\n"
219 "===========================\n"
220 "\n",
221 mbox_index,
222 readl(m->virtbase_peer + MBOX_FIFO_DATA),
223 readl(m->virtbase_peer + MBOX_FIFO_DATA),
224 readl(m->virtbase_peer + MBOX_FIFO_THRES_FREE),
225 readl(m->virtbase_peer + MBOX_FIFO_THRES_FREE),
226 readl(m->virtbase_peer + MBOX_FIFO_THRES_OCCUP),
227 readl(m->virtbase_peer + MBOX_FIFO_THRES_OCCUP),
228 readl(m->virtbase_peer + MBOX_FIFO_STATUS),
229 readl(m->virtbase_peer + MBOX_FIFO_STATUS),
230 (readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 4) & 0x7,
231 (readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 7) & 0x1,
232 (readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 0) & 0x7,
233 (readl(m->virtbase_peer + MBOX_FIFO_STATUS) >> 3) & 0x1,
234 readl(m->virtbase_local + MBOX_FIFO_DATA),
235 readl(m->virtbase_local + MBOX_FIFO_DATA),
236 readl(m->virtbase_local + MBOX_FIFO_THRES_FREE),
237 readl(m->virtbase_local + MBOX_FIFO_THRES_FREE),
238 readl(m->virtbase_local + MBOX_FIFO_THRES_OCCUP),
239 readl(m->virtbase_local + MBOX_FIFO_THRES_OCCUP),
240 readl(m->virtbase_local + MBOX_FIFO_STATUS),
241 readl(m->virtbase_local + MBOX_FIFO_STATUS),
242 (readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 4) & 0x7,
243 (readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 7) & 0x1,
244 (readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 0) & 0x7,
245 (readl(m->virtbase_local + MBOX_FIFO_STATUS) >> 3) & 0x1,
246 m->write_index, m->read_index);
247 mbox_index++;
248 spin_unlock(&m->lock);
249 }
250
251 return 0;
252}
253
254static int mbox_open(struct inode *inode, struct file *file)
255{
256 return single_open(file, mbox_show, NULL);
257}
258
259static const struct file_operations mbox_operations = {
260 .owner = THIS_MODULE,
261 .open = mbox_open,
262 .read = seq_read,
263 .llseek = seq_lseek,
264 .release = single_release,
265};
266#endif
267
268static irqreturn_t mbox_irq(int irq, void *arg)
269{
270 u32 mbox_value;
271 int nbr_occup;
272 int nbr_free;
273 struct mbox *mbox = (struct mbox *) arg;
274
275 spin_lock(&mbox->lock);
276
277 dev_dbg(&(mbox->pdev->dev),
278 "mbox IRQ [%d] received. ri = %d, wi = %d\n",
279 irq, mbox->read_index, mbox->write_index);
280
281
282
283
284
285 if (mbox->read_index != mbox->write_index) {
286
287
288
289
290 nbr_free = (readl(mbox->virtbase_local + MBOX_FIFO_STATUS)
291 >> 4) & 0x7;
292 dev_dbg(&(mbox->pdev->dev),
293 "Status indicates %d empty spaces in the FIFO!\n",
294 nbr_free);
295
296 while ((nbr_free > 0) &&
297 (mbox->read_index != mbox->write_index)) {
298
299 writel(mbox->buffer[mbox->read_index],
300 (mbox->virtbase_peer + MBOX_FIFO_DATA));
301 writel(MBOX_LATCH,
302 (mbox->virtbase_peer + MBOX_FIFO_ADD));
303 dev_dbg(&(mbox->pdev->dev),
304 "Wrote message 0x%X to addr 0x%X\n",
305 mbox->buffer[mbox->read_index],
306 (u32) (mbox->virtbase_peer + MBOX_FIFO_DATA));
307
308 nbr_free--;
309 mbox->read_index =
310 (mbox->read_index + 1) % MBOX_BUF_SIZE;
311 }
312
313
314
315
316
317 if (mbox->read_index != mbox->write_index) {
318 dev_dbg(&(mbox->pdev->dev),
319 "Still have messages to send, but FIFO full. "
320 "Request IRQ again!\n");
321 writel(MBOX_ENABLE_IRQ,
322 mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
323 } else {
324 dev_dbg(&(mbox->pdev->dev),
325 "No more messages to send. "
326 "Do not request IRQ again!\n");
327 writel(MBOX_DISABLE_IRQ,
328 mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
329 }
330
331
332
333
334
335 if (mbox->client_blocked &&
336 (((mbox->write_index + 1) % MBOX_BUF_SIZE)
337 != mbox->read_index)) {
338 dev_dbg(&(mbox->pdev->dev),
339 "Waking up blocked client\n");
340 complete(&mbox->buffer_available);
341 mbox->client_blocked = 0;
342 }
343 }
344
345
346 nbr_occup = readl(mbox->virtbase_local + MBOX_FIFO_STATUS) & 0x7;
347 if (nbr_occup == 0)
348 goto exit;
349
350 if (mbox->cb == NULL) {
351 dev_dbg(&(mbox->pdev->dev), "No receive callback registered, "
352 "leaving %d incoming messages in fifo!\n", nbr_occup);
353 goto exit;
354 }
355
356
357 mbox_value = readl(mbox->virtbase_local + MBOX_FIFO_DATA);
358 writel(MBOX_LATCH, (mbox->virtbase_local + MBOX_FIFO_REMOVE));
359
360
361 dev_dbg(&(mbox->pdev->dev), "Calling callback for message 0x%X!\n",
362 mbox_value);
363 mbox->cb(mbox_value, mbox->client_data);
364
365exit:
366 dev_dbg(&(mbox->pdev->dev), "Exit mbox IRQ. ri = %d, wi = %d\n",
367 mbox->read_index, mbox->write_index);
368 spin_unlock(&mbox->lock);
369
370 return IRQ_HANDLED;
371}
372
373
374struct mbox *mbox_setup(u8 mbox_id, mbox_recv_cb_t *mbox_cb, void *priv)
375{
376 struct resource *resource;
377 int irq;
378 int res;
379 struct mbox *mbox;
380
381 mbox = get_mbox_with_id(mbox_id);
382 if (mbox == NULL) {
383 dev_err(&(mbox->pdev->dev), "Incorrect mailbox id: %d!\n",
384 mbox_id);
385 goto exit;
386 }
387
388
389
390
391
392 if (mbox->allocated) {
393 dev_err(&(mbox->pdev->dev), "Mailbox number %d is busy!\n",
394 mbox_id);
395 mbox = NULL;
396 goto exit;
397 }
398 mbox->allocated = true;
399
400 dev_dbg(&(mbox->pdev->dev), "Initiating mailbox number %d: 0x%X...\n",
401 mbox_id, (u32)mbox);
402
403 mbox->client_data = priv;
404 mbox->cb = mbox_cb;
405
406
407 resource = platform_get_resource_byname(mbox->pdev,
408 IORESOURCE_MEM,
409 "mbox_peer");
410 if (resource == NULL) {
411 dev_err(&(mbox->pdev->dev),
412 "Unable to retrieve mbox peer resource\n");
413 mbox = NULL;
414 goto exit;
415 }
416 dev_dbg(&(mbox->pdev->dev),
417 "Resource name: %s start: 0x%X, end: 0x%X\n",
418 resource->name, resource->start, resource->end);
419 mbox->virtbase_peer =
420 ioremap(resource->start, resource->end - resource->start);
421 if (!mbox->virtbase_peer) {
422 dev_err(&(mbox->pdev->dev), "Unable to ioremap peer mbox\n");
423 mbox = NULL;
424 goto exit;
425 }
426 dev_dbg(&(mbox->pdev->dev),
427 "ioremapped peer physical: (0x%X-0x%X) to virtual: 0x%X\n",
428 resource->start, resource->end, (u32) mbox->virtbase_peer);
429
430
431 resource = platform_get_resource_byname(mbox->pdev,
432 IORESOURCE_MEM,
433 "mbox_local");
434 if (resource == NULL) {
435 dev_err(&(mbox->pdev->dev),
436 "Unable to retrieve mbox local resource\n");
437 mbox = NULL;
438 goto exit;
439 }
440 dev_dbg(&(mbox->pdev->dev),
441 "Resource name: %s start: 0x%X, end: 0x%X\n",
442 resource->name, resource->start, resource->end);
443 mbox->virtbase_local =
444 ioremap(resource->start, resource->end - resource->start);
445 if (!mbox->virtbase_local) {
446 dev_err(&(mbox->pdev->dev), "Unable to ioremap local mbox\n");
447 mbox = NULL;
448 goto exit;
449 }
450 dev_dbg(&(mbox->pdev->dev),
451 "ioremapped local physical: (0x%X-0x%X) to virtual: 0x%X\n",
452 resource->start, resource->end, (u32) mbox->virtbase_peer);
453
454 init_completion(&mbox->buffer_available);
455 mbox->client_blocked = 0;
456
457
458 irq = platform_get_irq_byname(mbox->pdev, "mbox_irq");
459 if (irq < 0) {
460 dev_err(&(mbox->pdev->dev),
461 "Unable to retrieve mbox irq resource\n");
462 mbox = NULL;
463 goto exit;
464 }
465
466 dev_dbg(&(mbox->pdev->dev), "Allocating irq %d...\n", irq);
467 res = request_irq(irq, mbox_irq, 0, mbox->name, (void *) mbox);
468 if (res < 0) {
469 dev_err(&(mbox->pdev->dev),
470 "Unable to allocate mbox irq %d\n", irq);
471 mbox = NULL;
472 goto exit;
473 }
474
475
476 writel(MBOX_DISABLE_IRQ, mbox->virtbase_peer + MBOX_FIFO_THRES_FREE);
477
478
479
480
481
482
483 if (mbox_cb != NULL)
484 writel(MBOX_ENABLE_IRQ,
485 mbox->virtbase_local + MBOX_FIFO_THRES_OCCUP);
486 else
487 writel(MBOX_DISABLE_IRQ,
488 mbox->virtbase_local + MBOX_FIFO_THRES_OCCUP);
489
490#if defined(CONFIG_DEBUG_FS)
491 res = device_create_file(&(mbox->pdev->dev), &dev_attr_fifo);
492 if (res != 0)
493 dev_warn(&(mbox->pdev->dev),
494 "Unable to create mbox sysfs entry");
495
496 (void) debugfs_create_file("mbox", S_IFREG | S_IRUGO, NULL,
497 NULL, &mbox_operations);
498#endif
499
500 dev_info(&(mbox->pdev->dev),
501 "Mailbox driver with index %d initated!\n", mbox_id);
502
503exit:
504 return mbox;
505}
506EXPORT_SYMBOL(mbox_setup);
507
508
509int __init mbox_probe(struct platform_device *pdev)
510{
511 struct mbox local_mbox;
512 struct mbox *mbox;
513 int res = 0;
514 dev_dbg(&(pdev->dev), "Probing mailbox (pdev = 0x%X)...\n", (u32) pdev);
515
516 memset(&local_mbox, 0x0, sizeof(struct mbox));
517
518
519 res = platform_device_add_data(pdev,
520 (void *) &local_mbox,
521 sizeof(struct mbox));
522 if (res != 0) {
523 dev_err(&(pdev->dev),
524 "Unable to allocate driver platform data!\n");
525 goto exit;
526 }
527
528 mbox = (struct mbox *) pdev->dev.platform_data;
529 mbox->pdev = pdev;
530 mbox->write_index = 0;
531 mbox->read_index = 0;
532
533 INIT_LIST_HEAD(&(mbox->list));
534 list_add_tail(&(mbox->list), &mboxs);
535
536 sprintf(mbox->name, "%s", MBOX_NAME);
537 spin_lock_init(&mbox->lock);
538
539 dev_info(&(pdev->dev), "Mailbox driver loaded\n");
540
541exit:
542 return res;
543}
544
545static struct platform_driver mbox_driver = {
546 .driver = {
547 .name = MBOX_NAME,
548 .owner = THIS_MODULE,
549 },
550};
551
552static int __init mbox_init(void)
553{
554 return platform_driver_probe(&mbox_driver, mbox_probe);
555}
556
557module_init(mbox_init);
558
559void __exit mbox_exit(void)
560{
561 platform_driver_unregister(&mbox_driver);
562}
563
564module_exit(mbox_exit);
565
566MODULE_LICENSE("GPL");
567MODULE_DESCRIPTION("MBOX driver");
568
