linux/drivers/mailbox/omap-mailbox.c

742 lines
18 KiB
C

/*
* OMAP mailbox driver
*
* Copyright (C) 2006-2009 Nokia Corporation. All rights reserved.
* Copyright (C) 2013-2014 Texas Instruments Inc.
*
* Contact: Hiroshi DOYU <Hiroshi.DOYU@nokia.com>
* Suman Anna <s-anna@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/interrupt.h>
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/kfifo.h>
#include <linux/err.h>
#include <linux/notifier.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/platform_data/mailbox-omap.h>
#include <linux/omap-mailbox.h>
#define MAILBOX_REVISION 0x000
#define MAILBOX_MESSAGE(m) (0x040 + 4 * (m))
#define MAILBOX_FIFOSTATUS(m) (0x080 + 4 * (m))
#define MAILBOX_MSGSTATUS(m) (0x0c0 + 4 * (m))
#define OMAP2_MAILBOX_IRQSTATUS(u) (0x100 + 8 * (u))
#define OMAP2_MAILBOX_IRQENABLE(u) (0x104 + 8 * (u))
#define OMAP4_MAILBOX_IRQSTATUS(u) (0x104 + 0x10 * (u))
#define OMAP4_MAILBOX_IRQENABLE(u) (0x108 + 0x10 * (u))
#define OMAP4_MAILBOX_IRQENABLE_CLR(u) (0x10c + 0x10 * (u))
#define MAILBOX_IRQSTATUS(type, u) (type ? OMAP4_MAILBOX_IRQSTATUS(u) : \
OMAP2_MAILBOX_IRQSTATUS(u))
#define MAILBOX_IRQENABLE(type, u) (type ? OMAP4_MAILBOX_IRQENABLE(u) : \
OMAP2_MAILBOX_IRQENABLE(u))
#define MAILBOX_IRQDISABLE(type, u) (type ? OMAP4_MAILBOX_IRQENABLE_CLR(u) \
: OMAP2_MAILBOX_IRQENABLE(u))
#define MAILBOX_IRQ_NEWMSG(m) (1 << (2 * (m)))
#define MAILBOX_IRQ_NOTFULL(m) (1 << (2 * (m) + 1))
#define MBOX_REG_SIZE 0x120
#define OMAP4_MBOX_REG_SIZE 0x130
#define MBOX_NR_REGS (MBOX_REG_SIZE / sizeof(u32))
#define OMAP4_MBOX_NR_REGS (OMAP4_MBOX_REG_SIZE / sizeof(u32))
struct omap_mbox_fifo {
unsigned long msg;
unsigned long fifo_stat;
unsigned long msg_stat;
unsigned long irqenable;
unsigned long irqstatus;
unsigned long irqdisable;
u32 intr_bit;
};
struct omap_mbox_queue {
spinlock_t lock;
struct kfifo fifo;
struct work_struct work;
struct tasklet_struct tasklet;
struct omap_mbox *mbox;
bool full;
};
struct omap_mbox_device {
struct device *dev;
struct mutex cfg_lock;
void __iomem *mbox_base;
u32 num_users;
u32 num_fifos;
struct omap_mbox **mboxes;
struct list_head elem;
};
struct omap_mbox {
const char *name;
int irq;
struct omap_mbox_queue *txq, *rxq;
struct device *dev;
struct omap_mbox_device *parent;
struct omap_mbox_fifo tx_fifo;
struct omap_mbox_fifo rx_fifo;
u32 ctx[OMAP4_MBOX_NR_REGS];
u32 intr_type;
int use_count;
struct blocking_notifier_head notifier;
};
/* global variables for the mailbox devices */
static DEFINE_MUTEX(omap_mbox_devices_lock);
static LIST_HEAD(omap_mbox_devices);
static unsigned int mbox_kfifo_size = CONFIG_OMAP_MBOX_KFIFO_SIZE;
module_param(mbox_kfifo_size, uint, S_IRUGO);
MODULE_PARM_DESC(mbox_kfifo_size, "Size of omap's mailbox kfifo (bytes)");
static inline
unsigned int mbox_read_reg(struct omap_mbox_device *mdev, size_t ofs)
{
return __raw_readl(mdev->mbox_base + ofs);
}
static inline
void mbox_write_reg(struct omap_mbox_device *mdev, u32 val, size_t ofs)
{
__raw_writel(val, mdev->mbox_base + ofs);
}
/* Mailbox FIFO handle functions */
static mbox_msg_t mbox_fifo_read(struct omap_mbox *mbox)
{
struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
return (mbox_msg_t) mbox_read_reg(mbox->parent, fifo->msg);
}
static void mbox_fifo_write(struct omap_mbox *mbox, mbox_msg_t msg)
{
struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
mbox_write_reg(mbox->parent, msg, fifo->msg);
}
static int mbox_fifo_empty(struct omap_mbox *mbox)
{
struct omap_mbox_fifo *fifo = &mbox->rx_fifo;
return (mbox_read_reg(mbox->parent, fifo->msg_stat) == 0);
}
static int mbox_fifo_full(struct omap_mbox *mbox)
{
struct omap_mbox_fifo *fifo = &mbox->tx_fifo;
return mbox_read_reg(mbox->parent, fifo->fifo_stat);
}
/* Mailbox IRQ handle functions */
static void ack_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
&mbox->tx_fifo : &mbox->rx_fifo;
u32 bit = fifo->intr_bit;
u32 irqstatus = fifo->irqstatus;
mbox_write_reg(mbox->parent, bit, irqstatus);
/* Flush posted write for irq status to avoid spurious interrupts */
mbox_read_reg(mbox->parent, irqstatus);
}
static int is_mbox_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
&mbox->tx_fifo : &mbox->rx_fifo;
u32 bit = fifo->intr_bit;
u32 irqenable = fifo->irqenable;
u32 irqstatus = fifo->irqstatus;
u32 enable = mbox_read_reg(mbox->parent, irqenable);
u32 status = mbox_read_reg(mbox->parent, irqstatus);
return (int)(enable & status & bit);
}
/*
* message sender
*/
int omap_mbox_msg_send(struct omap_mbox *mbox, mbox_msg_t msg)
{
struct omap_mbox_queue *mq = mbox->txq;
int ret = 0, len;
spin_lock_bh(&mq->lock);
if (kfifo_avail(&mq->fifo) < sizeof(msg)) {
ret = -ENOMEM;
goto out;
}
if (kfifo_is_empty(&mq->fifo) && !mbox_fifo_full(mbox)) {
mbox_fifo_write(mbox, msg);
goto out;
}
len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
WARN_ON(len != sizeof(msg));
tasklet_schedule(&mbox->txq->tasklet);
out:
spin_unlock_bh(&mq->lock);
return ret;
}
EXPORT_SYMBOL(omap_mbox_msg_send);
void omap_mbox_save_ctx(struct omap_mbox *mbox)
{
int i;
int nr_regs;
if (mbox->intr_type)
nr_regs = OMAP4_MBOX_NR_REGS;
else
nr_regs = MBOX_NR_REGS;
for (i = 0; i < nr_regs; i++) {
mbox->ctx[i] = mbox_read_reg(mbox->parent, i * sizeof(u32));
dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
i, mbox->ctx[i]);
}
}
EXPORT_SYMBOL(omap_mbox_save_ctx);
void omap_mbox_restore_ctx(struct omap_mbox *mbox)
{
int i;
int nr_regs;
if (mbox->intr_type)
nr_regs = OMAP4_MBOX_NR_REGS;
else
nr_regs = MBOX_NR_REGS;
for (i = 0; i < nr_regs; i++) {
mbox_write_reg(mbox->parent, mbox->ctx[i], i * sizeof(u32));
dev_dbg(mbox->dev, "%s: [%02x] %08x\n", __func__,
i, mbox->ctx[i]);
}
}
EXPORT_SYMBOL(omap_mbox_restore_ctx);
void omap_mbox_enable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
u32 l;
struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
&mbox->tx_fifo : &mbox->rx_fifo;
u32 bit = fifo->intr_bit;
u32 irqenable = fifo->irqenable;
l = mbox_read_reg(mbox->parent, irqenable);
l |= bit;
mbox_write_reg(mbox->parent, l, irqenable);
}
EXPORT_SYMBOL(omap_mbox_enable_irq);
void omap_mbox_disable_irq(struct omap_mbox *mbox, omap_mbox_irq_t irq)
{
struct omap_mbox_fifo *fifo = (irq == IRQ_TX) ?
&mbox->tx_fifo : &mbox->rx_fifo;
u32 bit = fifo->intr_bit;
u32 irqdisable = fifo->irqdisable;
/*
* Read and update the interrupt configuration register for pre-OMAP4.
* OMAP4 and later SoCs have a dedicated interrupt disabling register.
*/
if (!mbox->intr_type)
bit = mbox_read_reg(mbox->parent, irqdisable) & ~bit;
mbox_write_reg(mbox->parent, bit, irqdisable);
}
EXPORT_SYMBOL(omap_mbox_disable_irq);
static void mbox_tx_tasklet(unsigned long tx_data)
{
struct omap_mbox *mbox = (struct omap_mbox *)tx_data;
struct omap_mbox_queue *mq = mbox->txq;
mbox_msg_t msg;
int ret;
while (kfifo_len(&mq->fifo)) {
if (mbox_fifo_full(mbox)) {
omap_mbox_enable_irq(mbox, IRQ_TX);
break;
}
ret = kfifo_out(&mq->fifo, (unsigned char *)&msg,
sizeof(msg));
WARN_ON(ret != sizeof(msg));
mbox_fifo_write(mbox, msg);
}
}
/*
* Message receiver(workqueue)
*/
static void mbox_rx_work(struct work_struct *work)
{
struct omap_mbox_queue *mq =
container_of(work, struct omap_mbox_queue, work);
mbox_msg_t msg;
int len;
while (kfifo_len(&mq->fifo) >= sizeof(msg)) {
len = kfifo_out(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
WARN_ON(len != sizeof(msg));
blocking_notifier_call_chain(&mq->mbox->notifier, len,
(void *)msg);
spin_lock_irq(&mq->lock);
if (mq->full) {
mq->full = false;
omap_mbox_enable_irq(mq->mbox, IRQ_RX);
}
spin_unlock_irq(&mq->lock);
}
}
/*
* Mailbox interrupt handler
*/
static void __mbox_tx_interrupt(struct omap_mbox *mbox)
{
omap_mbox_disable_irq(mbox, IRQ_TX);
ack_mbox_irq(mbox, IRQ_TX);
tasklet_schedule(&mbox->txq->tasklet);
}
static void __mbox_rx_interrupt(struct omap_mbox *mbox)
{
struct omap_mbox_queue *mq = mbox->rxq;
mbox_msg_t msg;
int len;
while (!mbox_fifo_empty(mbox)) {
if (unlikely(kfifo_avail(&mq->fifo) < sizeof(msg))) {
omap_mbox_disable_irq(mbox, IRQ_RX);
mq->full = true;
goto nomem;
}
msg = mbox_fifo_read(mbox);
len = kfifo_in(&mq->fifo, (unsigned char *)&msg, sizeof(msg));
WARN_ON(len != sizeof(msg));
}
/* no more messages in the fifo. clear IRQ source. */
ack_mbox_irq(mbox, IRQ_RX);
nomem:
schedule_work(&mbox->rxq->work);
}
static irqreturn_t mbox_interrupt(int irq, void *p)
{
struct omap_mbox *mbox = p;
if (is_mbox_irq(mbox, IRQ_TX))
__mbox_tx_interrupt(mbox);
if (is_mbox_irq(mbox, IRQ_RX))
__mbox_rx_interrupt(mbox);
return IRQ_HANDLED;
}
static struct omap_mbox_queue *mbox_queue_alloc(struct omap_mbox *mbox,
void (*work) (struct work_struct *),
void (*tasklet)(unsigned long))
{
struct omap_mbox_queue *mq;
mq = kzalloc(sizeof(struct omap_mbox_queue), GFP_KERNEL);
if (!mq)
return NULL;
spin_lock_init(&mq->lock);
if (kfifo_alloc(&mq->fifo, mbox_kfifo_size, GFP_KERNEL))
goto error;
if (work)
INIT_WORK(&mq->work, work);
if (tasklet)
tasklet_init(&mq->tasklet, tasklet, (unsigned long)mbox);
return mq;
error:
kfree(mq);
return NULL;
}
static void mbox_queue_free(struct omap_mbox_queue *q)
{
kfifo_free(&q->fifo);
kfree(q);
}
static int omap_mbox_startup(struct omap_mbox *mbox)
{
int ret = 0;
struct omap_mbox_queue *mq;
struct omap_mbox_device *mdev = mbox->parent;
mutex_lock(&mdev->cfg_lock);
ret = pm_runtime_get_sync(mdev->dev);
if (unlikely(ret < 0))
goto fail_startup;
if (!mbox->use_count++) {
mq = mbox_queue_alloc(mbox, NULL, mbox_tx_tasklet);
if (!mq) {
ret = -ENOMEM;
goto fail_alloc_txq;
}
mbox->txq = mq;
mq = mbox_queue_alloc(mbox, mbox_rx_work, NULL);
if (!mq) {
ret = -ENOMEM;
goto fail_alloc_rxq;
}
mbox->rxq = mq;
mq->mbox = mbox;
ret = request_irq(mbox->irq, mbox_interrupt, IRQF_SHARED,
mbox->name, mbox);
if (unlikely(ret)) {
pr_err("failed to register mailbox interrupt:%d\n",
ret);
goto fail_request_irq;
}
omap_mbox_enable_irq(mbox, IRQ_RX);
}
mutex_unlock(&mdev->cfg_lock);
return 0;
fail_request_irq:
mbox_queue_free(mbox->rxq);
fail_alloc_rxq:
mbox_queue_free(mbox->txq);
fail_alloc_txq:
pm_runtime_put_sync(mdev->dev);
mbox->use_count--;
fail_startup:
mutex_unlock(&mdev->cfg_lock);
return ret;
}
static void omap_mbox_fini(struct omap_mbox *mbox)
{
struct omap_mbox_device *mdev = mbox->parent;
mutex_lock(&mdev->cfg_lock);
if (!--mbox->use_count) {
omap_mbox_disable_irq(mbox, IRQ_RX);
free_irq(mbox->irq, mbox);
tasklet_kill(&mbox->txq->tasklet);
flush_work(&mbox->rxq->work);
mbox_queue_free(mbox->txq);
mbox_queue_free(mbox->rxq);
}
pm_runtime_put_sync(mdev->dev);
mutex_unlock(&mdev->cfg_lock);
}
static struct omap_mbox *omap_mbox_device_find(struct omap_mbox_device *mdev,
const char *mbox_name)
{
struct omap_mbox *_mbox, *mbox = NULL;
struct omap_mbox **mboxes = mdev->mboxes;
int i;
if (!mboxes)
return NULL;
for (i = 0; (_mbox = mboxes[i]); i++) {
if (!strcmp(_mbox->name, mbox_name)) {
mbox = _mbox;
break;
}
}
return mbox;
}
struct omap_mbox *omap_mbox_get(const char *name, struct notifier_block *nb)
{
struct omap_mbox *mbox = NULL;
struct omap_mbox_device *mdev;
int ret;
mutex_lock(&omap_mbox_devices_lock);
list_for_each_entry(mdev, &omap_mbox_devices, elem) {
mbox = omap_mbox_device_find(mdev, name);
if (mbox)
break;
}
mutex_unlock(&omap_mbox_devices_lock);
if (!mbox)
return ERR_PTR(-ENOENT);
if (nb)
blocking_notifier_chain_register(&mbox->notifier, nb);
ret = omap_mbox_startup(mbox);
if (ret) {
blocking_notifier_chain_unregister(&mbox->notifier, nb);
return ERR_PTR(-ENODEV);
}
return mbox;
}
EXPORT_SYMBOL(omap_mbox_get);
void omap_mbox_put(struct omap_mbox *mbox, struct notifier_block *nb)
{
blocking_notifier_chain_unregister(&mbox->notifier, nb);
omap_mbox_fini(mbox);
}
EXPORT_SYMBOL(omap_mbox_put);
static struct class omap_mbox_class = { .name = "mbox", };
static int omap_mbox_register(struct omap_mbox_device *mdev)
{
int ret;
int i;
struct omap_mbox **mboxes;
if (!mdev || !mdev->mboxes)
return -EINVAL;
mboxes = mdev->mboxes;
for (i = 0; mboxes[i]; i++) {
struct omap_mbox *mbox = mboxes[i];
mbox->dev = device_create(&omap_mbox_class,
mdev->dev, 0, mbox, "%s", mbox->name);
if (IS_ERR(mbox->dev)) {
ret = PTR_ERR(mbox->dev);
goto err_out;
}
BLOCKING_INIT_NOTIFIER_HEAD(&mbox->notifier);
}
mutex_lock(&omap_mbox_devices_lock);
list_add(&mdev->elem, &omap_mbox_devices);
mutex_unlock(&omap_mbox_devices_lock);
return 0;
err_out:
while (i--)
device_unregister(mboxes[i]->dev);
return ret;
}
static int omap_mbox_unregister(struct omap_mbox_device *mdev)
{
int i;
struct omap_mbox **mboxes;
if (!mdev || !mdev->mboxes)
return -EINVAL;
mutex_lock(&omap_mbox_devices_lock);
list_del(&mdev->elem);
mutex_unlock(&omap_mbox_devices_lock);
mboxes = mdev->mboxes;
for (i = 0; mboxes[i]; i++)
device_unregister(mboxes[i]->dev);
return 0;
}
static int omap_mbox_probe(struct platform_device *pdev)
{
struct resource *mem;
int ret;
struct omap_mbox **list, *mbox, *mboxblk;
struct omap_mbox_pdata *pdata = pdev->dev.platform_data;
struct omap_mbox_dev_info *info;
struct omap_mbox_device *mdev;
struct omap_mbox_fifo *fifo;
u32 intr_type;
u32 l;
int i;
if (!pdata || !pdata->info_cnt || !pdata->info) {
pr_err("%s: platform not supported\n", __func__);
return -ENODEV;
}
mdev = devm_kzalloc(&pdev->dev, sizeof(*mdev), GFP_KERNEL);
if (!mdev)
return -ENOMEM;
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
mdev->mbox_base = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(mdev->mbox_base))
return PTR_ERR(mdev->mbox_base);
/* allocate one extra for marking end of list */
list = devm_kzalloc(&pdev->dev, (pdata->info_cnt + 1) * sizeof(*list),
GFP_KERNEL);
if (!list)
return -ENOMEM;
mboxblk = devm_kzalloc(&pdev->dev, pdata->info_cnt * sizeof(*mbox),
GFP_KERNEL);
if (!mboxblk)
return -ENOMEM;
info = pdata->info;
intr_type = pdata->intr_type;
mbox = mboxblk;
for (i = 0; i < pdata->info_cnt; i++, info++) {
fifo = &mbox->tx_fifo;
fifo->msg = MAILBOX_MESSAGE(info->tx_id);
fifo->fifo_stat = MAILBOX_FIFOSTATUS(info->tx_id);
fifo->intr_bit = MAILBOX_IRQ_NOTFULL(info->tx_id);
fifo->irqenable = MAILBOX_IRQENABLE(intr_type, info->usr_id);
fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, info->usr_id);
fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, info->usr_id);
fifo = &mbox->rx_fifo;
fifo->msg = MAILBOX_MESSAGE(info->rx_id);
fifo->msg_stat = MAILBOX_MSGSTATUS(info->rx_id);
fifo->intr_bit = MAILBOX_IRQ_NEWMSG(info->rx_id);
fifo->irqenable = MAILBOX_IRQENABLE(intr_type, info->usr_id);
fifo->irqstatus = MAILBOX_IRQSTATUS(intr_type, info->usr_id);
fifo->irqdisable = MAILBOX_IRQDISABLE(intr_type, info->usr_id);
mbox->intr_type = intr_type;
mbox->parent = mdev;
mbox->name = info->name;
mbox->irq = platform_get_irq(pdev, info->irq_id);
if (mbox->irq < 0)
return mbox->irq;
list[i] = mbox++;
}
mutex_init(&mdev->cfg_lock);
mdev->dev = &pdev->dev;
mdev->num_users = pdata->num_users;
mdev->num_fifos = pdata->num_fifos;
mdev->mboxes = list;
ret = omap_mbox_register(mdev);
if (ret)
return ret;
platform_set_drvdata(pdev, mdev);
pm_runtime_enable(mdev->dev);
ret = pm_runtime_get_sync(mdev->dev);
if (ret < 0) {
pm_runtime_put_noidle(mdev->dev);
goto unregister;
}
/*
* just print the raw revision register, the format is not
* uniform across all SoCs
*/
l = mbox_read_reg(mdev, MAILBOX_REVISION);
dev_info(mdev->dev, "omap mailbox rev 0x%x\n", l);
ret = pm_runtime_put_sync(mdev->dev);
if (ret < 0)
goto unregister;
return 0;
unregister:
pm_runtime_disable(mdev->dev);
omap_mbox_unregister(mdev);
return ret;
}
static int omap_mbox_remove(struct platform_device *pdev)
{
struct omap_mbox_device *mdev = platform_get_drvdata(pdev);
pm_runtime_disable(mdev->dev);
omap_mbox_unregister(mdev);
return 0;
}
static struct platform_driver omap_mbox_driver = {
.probe = omap_mbox_probe,
.remove = omap_mbox_remove,
.driver = {
.name = "omap-mailbox",
.owner = THIS_MODULE,
},
};
static int __init omap_mbox_init(void)
{
int err;
err = class_register(&omap_mbox_class);
if (err)
return err;
/* kfifo size sanity check: alignment and minimal size */
mbox_kfifo_size = ALIGN(mbox_kfifo_size, sizeof(mbox_msg_t));
mbox_kfifo_size = max_t(unsigned int, mbox_kfifo_size,
sizeof(mbox_msg_t));
return platform_driver_register(&omap_mbox_driver);
}
subsys_initcall(omap_mbox_init);
static void __exit omap_mbox_exit(void)
{
platform_driver_unregister(&omap_mbox_driver);
class_unregister(&omap_mbox_class);
}
module_exit(omap_mbox_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("omap mailbox: interrupt driven messaging");
MODULE_AUTHOR("Toshihiro Kobayashi");
MODULE_AUTHOR("Hiroshi DOYU");