4 * Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
6 * Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * version 2 as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
24 #include <linux/interrupt.h>
25 #include <linux/spinlock.h>
26 #include <linux/mutex.h>
27 #include <linux/delay.h>
28 #include <linux/slab.h>
29 #include <linux/kfifo.h>
30 #include <linux/err.h>
31 #include <linux/notifier.h>
33 #include <plat/mailbox.h>
35 static struct omap_mbox **mboxes;
37 static int mbox_configured;
38 static DEFINE_MUTEX(mbox_configured_lock);
40 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
41 module_param(mbox_kfifo_size, uint, S_IRUGO);
42 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
44 /* Mailbox FIFO handle functions */
45 static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
47 return mbox->ops->fifo_read(mbox);
49 static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
51 mbox->ops->fifo_write(mbox, msg);
53 static inline int mbox_fifo_empty(struct omap_mbox *mbox)
55 return mbox->ops->fifo_empty(mbox);
57 static inline int mbox_fifo_full(struct omap_mbox *mbox)
59 return mbox->ops->fifo_full(mbox);
62 /* Mailbox IRQ handle functions */
63 static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
65 if (mbox->ops->ack_irq)
66 mbox->ops->ack_irq(mbox, irq);
68 static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
70 return mbox->ops->is_irq(mbox, irq);
76 static int __mbox_poll_for_space(struct omap_mbox *mbox)
78 int ret = 0, i = 1000;
80 while (mbox_fifo_full(mbox)) {
81 if (mbox->ops->type == OMAP_MBOX_TYPE2)
90 int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
92 struct omap_mbox_queue *mq = mbox->txq;
95 spin_lock_bh(&mq->lock);
97 if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
102 if (kfifo_is_empty(&mq->fifo) && !__mbox_poll_for_space(mbox)) {
103 mbox_fifo_write(mbox, msg);
107 len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
108 WARN_ON(len != sizeof(msg));
110 tasklet_schedule(&mbox->txq->tasklet);
113 spin_unlock_bh(&mq->lock);
116 EXPORT_SYMBOL(omap_mbox_msg_send);
118 static void mbox_tx_tasklet(unsigned long tx_data)
120 struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
121 struct omap_mbox_queue *mq = mbox->txq;
125 while (kfifo_len(&mq->fifo)) {
126 if (__mbox_poll_for_space(mbox)) {
127 omap_mbox_enable_irq(mbox, IRQ_TX);
131 ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
133 WARN_ON(ret != sizeof(msg));
135 mbox_fifo_write(mbox, msg);
140 * Message receiver(workqueue)
142 static void mbox_rx_work(struct work_struct *work)
144 struct omap_mbox_queue *mq =
145 container_of(work, struct omap_mbox_queue, work);
149 while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
150 len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
151 WARN_ON(len != sizeof(msg));
153 blocking_notifier_call_chain(&mq->mbox->notifier, len,
155 spin_lock_irq(&mq->lock);
158 omap_mbox_enable_irq(mq->mbox, IRQ_RX);
160 spin_unlock_irq(&mq->lock);
165 * Mailbox interrupt handler
167 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
169 omap_mbox_disable_irq(mbox, IRQ_TX);
170 ack_mbox_irq(mbox, IRQ_TX);
171 tasklet_schedule(&mbox->txq->tasklet);
174 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
176 struct omap_mbox_queue *mq = mbox->rxq;
180 while (!mbox_fifo_empty(mbox)) {
181 if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
182 omap_mbox_disable_irq(mbox, IRQ_RX);
187 msg = mbox_fifo_read(mbox);
189 len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
190 WARN_ON(len != sizeof(msg));
192 if (mbox->ops->type == OMAP_MBOX_TYPE1)
196 /* no more messages in the fifo. clear IRQ source. */
197 ack_mbox_irq(mbox, IRQ_RX);
199 schedule_work(&mbox->rxq->work);
202 static irqreturn_t mbox_interrupt(int irq, void *p)
204 struct omap_mbox *mbox = p;
206 if (is_mbox_irq(mbox, IRQ_TX))
207 __mbox_tx_interrupt(mbox);
209 if (is_mbox_irq(mbox, IRQ_RX))
210 __mbox_rx_interrupt(mbox);
215 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
216 void (*work) (struct work_struct *),
217 void (*tasklet)(unsigned long))
219 struct omap_mbox_queue *mq;
221 mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
225 spin_lock_init(&mq->lock);
227 if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
231 INIT_WORK(&mq->work, work);
234 tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
241 static void mbox_queue_free(struct omap_mbox_queue *q)
243 kfifo_free(&q->fifo);
247 static int omap_mbox_startup(struct omap_mbox *mbox)
250 struct omap_mbox_queue *mq;
252 mutex_lock(&mbox_configured_lock);
253 if (!mbox_configured++) {
254 if (likely(mbox->ops->startup)) {
255 ret = mbox->ops->startup(mbox);
262 if (!mbox->use_count++) {
263 ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
266 pr_err("failed to register mailbox interrupt:%d\n",
268 goto fail_request_irq;
270 mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
277 mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
285 mutex_unlock(&mbox_configured_lock);
289 mbox_queue_free(mbox->txq);
291 free_irq(mbox->irq, mbox);
293 if (mbox->ops->shutdown)
294 mbox->ops->shutdown(mbox);
298 mutex_unlock(&mbox_configured_lock);
302 static void omap_mbox_fini(struct omap_mbox *mbox)
304 mutex_lock(&mbox_configured_lock);
306 if (!--mbox->use_count) {
307 free_irq(mbox->irq, mbox);
308 tasklet_kill(&mbox->txq->tasklet);
309 flush_work_sync(&mbox->rxq->work);
310 mbox_queue_free(mbox->txq);
311 mbox_queue_free(mbox->rxq);
314 if (likely(mbox->ops->shutdown)) {
315 if (!--mbox_configured)
316 mbox->ops->shutdown(mbox);
319 mutex_unlock(&mbox_configured_lock);
322 struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
324 struct omap_mbox *_mbox, *mbox = NULL;
328 return ERR_PTR(-EINVAL);
330 for (i = 0; (_mbox = mboxes[i]); i++) {
331 if (!strcmp(_mbox->name, name)) {
338 return ERR_PTR(-ENOENT);
340 ret = omap_mbox_startup(mbox);
342 return ERR_PTR(-ENODEV);
345 blocking_notifier_chain_register(&mbox->notifier, nb);
349 EXPORT_SYMBOL(omap_mbox_get);
351 void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
353 blocking_notifier_chain_unregister(&mbox->notifier, nb);
354 omap_mbox_fini(mbox);
356 EXPORT_SYMBOL(omap_mbox_put);
358 static struct class omap_mbox_class = { .name = "mbox", };
360 int omap_mbox_register(struct device *parent, struct omap_mbox **list)
369 for (i = 0; mboxes[i]; i++) {
370 struct omap_mbox *mbox = mboxes[i];
371 mbox->dev = device_create(&omap_mbox_class,
372 parent, 0, mbox, "%s", mbox->name);
373 if (IS_ERR(mbox->dev)) {
374 ret = PTR_ERR(mbox->dev);
378 BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
384 device_unregister(mboxes[i]->dev);
387 EXPORT_SYMBOL(omap_mbox_register);
389 int omap_mbox_unregister(void)
396 for (i = 0; mboxes[i]; i++)
397 device_unregister(mboxes[i]->dev);
401 EXPORT_SYMBOL(omap_mbox_unregister);
403 static int __init omap_mbox_init(void)
407 err = class_register(&omap_mbox_class);
411 /* kfifo size sanity check: alignment and minimal size */
412 mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
413 mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
418 subsys_initcall(omap_mbox_init);
420 static void __exit omap_mbox_exit(void)
422 class_unregister(&omap_mbox_class);
424 module_exit(omap_mbox_exit);
426 MODULE_LICENSE("GPL v2");
427 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
428 MODULE_AUTHOR("Toshihiro Kobayashi");
429 MODULE_AUTHOR("Hiroshi DOYU");