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>
32 #include <plat/mailbox.h>
34 static struct workqueue_struct *mboxd;
35 static struct omap_mbox **mboxes;
38 static int mbox_configured;
39 static DEFINE_MUTEX(mbox_configured_lock);
41 static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
42 module_param(mbox_kfifo_size, uint, S_IRUGO);
43 MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
45 /* Mailbox FIFO handle functions */
46 static inline mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
48 return mbox->ops->fifo_read(mbox);
50 static inline void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
52 mbox->ops->fifo_write(mbox, msg);
54 static inline int mbox_fifo_empty(struct omap_mbox *mbox)
56 return mbox->ops->fifo_empty(mbox);
58 static inline int mbox_fifo_full(struct omap_mbox *mbox)
60 return mbox->ops->fifo_full(mbox);
63 /* Mailbox IRQ handle functions */
64 static inline void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
66 if (mbox->ops->ack_irq)
67 mbox->ops->ack_irq(mbox, irq);
69 static inline int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
71 return mbox->ops->is_irq(mbox, irq);
77 static int __mbox_poll_for_space(struct omap_mbox *mbox)
79 int ret = 0, i = 1000;
81 while (mbox_fifo_full(mbox)) {
82 if (mbox->ops->type == OMAP_MBOX_TYPE2)
91 int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
93 struct omap_mbox_queue *mq = mbox->txq;
98 if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
103 len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
104 WARN_ON(len != sizeof(msg));
106 tasklet_schedule(&mbox->txq->tasklet);
109 spin_unlock(&mq->lock);
112 EXPORT_SYMBOL(omap_mbox_msg_send);
114 static void mbox_tx_tasklet(unsigned long tx_data)
116 struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
117 struct omap_mbox_queue *mq = mbox->txq;
121 while (kfifo_len(&mq->fifo)) {
122 if (__mbox_poll_for_space(mbox)) {
123 omap_mbox_enable_irq(mbox, IRQ_TX);
127 ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
129 WARN_ON(ret != sizeof(msg));
131 mbox_fifo_write(mbox, msg);
136 * Message receiver(workqueue)
138 static void mbox_rx_work(struct work_struct *work)
140 struct omap_mbox_queue *mq =
141 container_of(work, struct omap_mbox_queue, work);
145 while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
146 len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
147 WARN_ON(len != sizeof(msg));
150 mq->callback((void *)msg);
155 * Mailbox interrupt handler
157 static void __mbox_tx_interrupt(struct omap_mbox *mbox)
159 omap_mbox_disable_irq(mbox, IRQ_TX);
160 ack_mbox_irq(mbox, IRQ_TX);
161 tasklet_schedule(&mbox->txq->tasklet);
164 static void __mbox_rx_interrupt(struct omap_mbox *mbox)
166 struct omap_mbox_queue *mq = mbox->rxq;
170 while (!mbox_fifo_empty(mbox)) {
171 if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
172 omap_mbox_disable_irq(mbox, IRQ_RX);
177 msg = mbox_fifo_read(mbox);
179 len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
180 WARN_ON(len != sizeof(msg));
182 if (mbox->ops->type == OMAP_MBOX_TYPE1)
186 /* no more messages in the fifo. clear IRQ source. */
187 ack_mbox_irq(mbox, IRQ_RX);
189 queue_work(mboxd, &mbox->rxq->work);
192 static irqreturn_t mbox_interrupt(int irq, void *p)
194 struct omap_mbox *mbox = p;
196 if (is_mbox_irq(mbox, IRQ_TX))
197 __mbox_tx_interrupt(mbox);
199 if (is_mbox_irq(mbox, IRQ_RX))
200 __mbox_rx_interrupt(mbox);
205 static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
206 void (*work) (struct work_struct *),
207 void (*tasklet)(unsigned long))
209 struct omap_mbox_queue *mq;
211 mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
215 spin_lock_init(&mq->lock);
217 if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
221 INIT_WORK(&mq->work, work);
224 tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
231 static void mbox_queue_free(struct omap_mbox_queue *q)
233 kfifo_free(&q->fifo);
237 static int omap_mbox_startup(struct omap_mbox *mbox)
240 struct omap_mbox_queue *mq;
242 if (mbox->ops->startup) {
243 mutex_lock(&mbox_configured_lock);
244 if (!mbox_configured)
245 ret = mbox->ops->startup(mbox);
248 mutex_unlock(&mbox_configured_lock);
252 mutex_unlock(&mbox_configured_lock);
255 ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
259 "failed to register mailbox interrupt:%d\n", ret);
260 goto fail_request_irq;
263 mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
270 mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
280 mbox_queue_free(mbox->txq);
282 free_irq(mbox->irq, mbox);
284 if (mbox->ops->shutdown)
285 mbox->ops->shutdown(mbox);
290 static void omap_mbox_fini(struct omap_mbox *mbox)
292 free_irq(mbox->irq, mbox);
293 tasklet_kill(&mbox->txq->tasklet);
294 flush_work(&mbox->rxq->work);
295 mbox_queue_free(mbox->txq);
296 mbox_queue_free(mbox->rxq);
298 if (mbox->ops->shutdown) {
299 mutex_lock(&mbox_configured_lock);
300 if (mbox_configured > 0)
302 if (!mbox_configured)
303 mbox->ops->shutdown(mbox);
304 mutex_unlock(&mbox_configured_lock);
308 struct omap_mbox *omap_mbox_get(const char *name)
310 struct omap_mbox *mbox;
314 return ERR_PTR(-EINVAL);
316 for (mbox = *mboxes; mbox; mbox++)
317 if (!strcmp(mbox->name, name))
321 return ERR_PTR(-ENOENT);
323 ret = omap_mbox_startup(mbox);
325 return ERR_PTR(-ENODEV);
329 EXPORT_SYMBOL(omap_mbox_get);
331 void omap_mbox_put(struct omap_mbox *mbox)
333 omap_mbox_fini(mbox);
335 EXPORT_SYMBOL(omap_mbox_put);
337 static struct class omap_mbox_class = { .name = "mbox", };
339 int omap_mbox_register(struct device *parent, struct omap_mbox **list)
348 for (i = 0; mboxes[i]; i++) {
349 struct omap_mbox *mbox = mboxes[i];
350 mbox->dev = device_create(&omap_mbox_class,
351 parent, 0, mbox, "%s", mbox->name);
352 if (IS_ERR(mbox->dev)) {
353 ret = PTR_ERR(mbox->dev);
361 device_unregister(mboxes[i]->dev);
364 EXPORT_SYMBOL(omap_mbox_register);
366 int omap_mbox_unregister(void)
373 for (i = 0; mboxes[i]; i++)
374 device_unregister(mboxes[i]->dev);
378 EXPORT_SYMBOL(omap_mbox_unregister);
380 static int __init omap_mbox_init(void)
384 err = class_register(&omap_mbox_class);
388 mboxd = create_workqueue("mboxd");
392 /* kfifo size sanity check: alignment and minimal size */
393 mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
394 mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size, sizeof(mbox_msg_t));
398 subsys_initcall(omap_mbox_init);
400 static void __exit omap_mbox_exit(void)
402 destroy_workqueue(mboxd);
403 class_unregister(&omap_mbox_class);
405 module_exit(omap_mbox_exit);
407 MODULE_LICENSE("GPL v2");
408 MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
409 MODULE_AUTHOR("Toshihiro Kobayashi");
410 MODULE_AUTHOR("Hiroshi DOYU");