389 lines
9.2 KiB
C
389 lines
9.2 KiB
C
/*
|
|
* Copyright Altera Corporation (C) 2013-2014. All rights reserved
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms and conditions of the GNU General Public License,
|
|
* version 2, as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/mailbox_controller.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/platform_device.h>
|
|
|
|
#define DRIVER_NAME "altera-mailbox"
|
|
|
|
#define MAILBOX_CMD_REG 0x00
|
|
#define MAILBOX_PTR_REG 0x04
|
|
#define MAILBOX_STS_REG 0x08
|
|
#define MAILBOX_INTMASK_REG 0x0C
|
|
|
|
#define INT_PENDING_MSK 0x1
|
|
#define INT_SPACE_MSK 0x2
|
|
|
|
#define STS_PENDING_MSK 0x1
|
|
#define STS_FULL_MSK 0x2
|
|
#define STS_FULL_OFT 0x1
|
|
|
|
#define MBOX_PENDING(status) (((status) & STS_PENDING_MSK))
|
|
#define MBOX_FULL(status) (((status) & STS_FULL_MSK) >> STS_FULL_OFT)
|
|
|
|
enum altera_mbox_msg {
|
|
MBOX_CMD = 0,
|
|
MBOX_PTR,
|
|
};
|
|
|
|
#define MBOX_POLLING_MS 5 /* polling interval 5ms */
|
|
|
|
struct altera_mbox {
|
|
bool is_sender; /* 1-sender, 0-receiver */
|
|
bool intr_mode;
|
|
int irq;
|
|
void __iomem *mbox_base;
|
|
struct device *dev;
|
|
struct mbox_controller controller;
|
|
|
|
/* If the controller supports only RX polling mode */
|
|
struct timer_list rxpoll_timer;
|
|
};
|
|
|
|
static struct altera_mbox *mbox_chan_to_altera_mbox(struct mbox_chan *chan)
|
|
{
|
|
if (!chan || !chan->con_priv)
|
|
return NULL;
|
|
|
|
return (struct altera_mbox *)chan->con_priv;
|
|
}
|
|
|
|
static inline int altera_mbox_full(struct altera_mbox *mbox)
|
|
{
|
|
u32 status;
|
|
|
|
status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
|
|
return MBOX_FULL(status);
|
|
}
|
|
|
|
static inline int altera_mbox_pending(struct altera_mbox *mbox)
|
|
{
|
|
u32 status;
|
|
|
|
status = readl_relaxed(mbox->mbox_base + MAILBOX_STS_REG);
|
|
return MBOX_PENDING(status);
|
|
}
|
|
|
|
static void altera_mbox_rx_intmask(struct altera_mbox *mbox, bool enable)
|
|
{
|
|
u32 mask;
|
|
|
|
mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
|
|
if (enable)
|
|
mask |= INT_PENDING_MSK;
|
|
else
|
|
mask &= ~INT_PENDING_MSK;
|
|
writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
|
|
}
|
|
|
|
static void altera_mbox_tx_intmask(struct altera_mbox *mbox, bool enable)
|
|
{
|
|
u32 mask;
|
|
|
|
mask = readl_relaxed(mbox->mbox_base + MAILBOX_INTMASK_REG);
|
|
if (enable)
|
|
mask |= INT_SPACE_MSK;
|
|
else
|
|
mask &= ~INT_SPACE_MSK;
|
|
writel_relaxed(mask, mbox->mbox_base + MAILBOX_INTMASK_REG);
|
|
}
|
|
|
|
static bool altera_mbox_is_sender(struct altera_mbox *mbox)
|
|
{
|
|
u32 reg;
|
|
/* Write a magic number to PTR register and read back this register.
|
|
* This register is read-write if it is a sender.
|
|
*/
|
|
#define MBOX_MAGIC 0xA5A5AA55
|
|
writel_relaxed(MBOX_MAGIC, mbox->mbox_base + MAILBOX_PTR_REG);
|
|
reg = readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
|
|
if (reg == MBOX_MAGIC) {
|
|
/* Clear to 0 */
|
|
writel_relaxed(0, mbox->mbox_base + MAILBOX_PTR_REG);
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
static void altera_mbox_rx_data(struct mbox_chan *chan)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
u32 data[2];
|
|
|
|
if (altera_mbox_pending(mbox)) {
|
|
data[MBOX_PTR] =
|
|
readl_relaxed(mbox->mbox_base + MAILBOX_PTR_REG);
|
|
data[MBOX_CMD] =
|
|
readl_relaxed(mbox->mbox_base + MAILBOX_CMD_REG);
|
|
mbox_chan_received_data(chan, (void *)data);
|
|
}
|
|
}
|
|
|
|
static void altera_mbox_poll_rx(unsigned long data)
|
|
{
|
|
struct mbox_chan *chan = (struct mbox_chan *)data;
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
altera_mbox_rx_data(chan);
|
|
|
|
mod_timer(&mbox->rxpoll_timer,
|
|
jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
|
|
}
|
|
|
|
static irqreturn_t altera_mbox_tx_interrupt(int irq, void *p)
|
|
{
|
|
struct mbox_chan *chan = (struct mbox_chan *)p;
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
altera_mbox_tx_intmask(mbox, false);
|
|
mbox_chan_txdone(chan, 0);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static irqreturn_t altera_mbox_rx_interrupt(int irq, void *p)
|
|
{
|
|
struct mbox_chan *chan = (struct mbox_chan *)p;
|
|
|
|
altera_mbox_rx_data(chan);
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int altera_mbox_startup_sender(struct mbox_chan *chan)
|
|
{
|
|
int ret;
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
if (mbox->intr_mode) {
|
|
ret = request_irq(mbox->irq, altera_mbox_tx_interrupt, 0,
|
|
DRIVER_NAME, chan);
|
|
if (unlikely(ret)) {
|
|
dev_err(mbox->dev,
|
|
"failed to register mailbox interrupt:%d\n",
|
|
ret);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int altera_mbox_startup_receiver(struct mbox_chan *chan)
|
|
{
|
|
int ret;
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
if (mbox->intr_mode) {
|
|
ret = request_irq(mbox->irq, altera_mbox_rx_interrupt, 0,
|
|
DRIVER_NAME, chan);
|
|
if (unlikely(ret)) {
|
|
mbox->intr_mode = false;
|
|
goto polling; /* use polling if failed */
|
|
}
|
|
|
|
altera_mbox_rx_intmask(mbox, true);
|
|
return 0;
|
|
}
|
|
|
|
polling:
|
|
/* Setup polling timer */
|
|
setup_timer(&mbox->rxpoll_timer, altera_mbox_poll_rx,
|
|
(unsigned long)chan);
|
|
mod_timer(&mbox->rxpoll_timer,
|
|
jiffies + msecs_to_jiffies(MBOX_POLLING_MS));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int altera_mbox_send_data(struct mbox_chan *chan, void *data)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
u32 *udata = (u32 *)data;
|
|
|
|
if (!mbox || !data)
|
|
return -EINVAL;
|
|
if (!mbox->is_sender) {
|
|
dev_warn(mbox->dev,
|
|
"failed to send. This is receiver mailbox.\n");
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (altera_mbox_full(mbox))
|
|
return -EBUSY;
|
|
|
|
/* Enable interrupt before send */
|
|
if (mbox->intr_mode)
|
|
altera_mbox_tx_intmask(mbox, true);
|
|
|
|
/* Pointer register must write before command register */
|
|
writel_relaxed(udata[MBOX_PTR], mbox->mbox_base + MAILBOX_PTR_REG);
|
|
writel_relaxed(udata[MBOX_CMD], mbox->mbox_base + MAILBOX_CMD_REG);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static bool altera_mbox_last_tx_done(struct mbox_chan *chan)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
/* Return false if mailbox is full */
|
|
return altera_mbox_full(mbox) ? false : true;
|
|
}
|
|
|
|
static bool altera_mbox_peek_data(struct mbox_chan *chan)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
return altera_mbox_pending(mbox) ? true : false;
|
|
}
|
|
|
|
static int altera_mbox_startup(struct mbox_chan *chan)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
int ret = 0;
|
|
|
|
if (!mbox)
|
|
return -EINVAL;
|
|
|
|
if (mbox->is_sender)
|
|
ret = altera_mbox_startup_sender(chan);
|
|
else
|
|
ret = altera_mbox_startup_receiver(chan);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void altera_mbox_shutdown(struct mbox_chan *chan)
|
|
{
|
|
struct altera_mbox *mbox = mbox_chan_to_altera_mbox(chan);
|
|
|
|
if (mbox->intr_mode) {
|
|
/* Unmask all interrupt masks */
|
|
writel_relaxed(~0, mbox->mbox_base + MAILBOX_INTMASK_REG);
|
|
free_irq(mbox->irq, chan);
|
|
} else if (!mbox->is_sender) {
|
|
del_timer_sync(&mbox->rxpoll_timer);
|
|
}
|
|
}
|
|
|
|
static struct mbox_chan_ops altera_mbox_ops = {
|
|
.send_data = altera_mbox_send_data,
|
|
.startup = altera_mbox_startup,
|
|
.shutdown = altera_mbox_shutdown,
|
|
.last_tx_done = altera_mbox_last_tx_done,
|
|
.peek_data = altera_mbox_peek_data,
|
|
};
|
|
|
|
static int altera_mbox_probe(struct platform_device *pdev)
|
|
{
|
|
struct altera_mbox *mbox;
|
|
struct resource *regs;
|
|
struct mbox_chan *chans;
|
|
int ret;
|
|
|
|
mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox),
|
|
GFP_KERNEL);
|
|
if (!mbox)
|
|
return -ENOMEM;
|
|
|
|
/* Allocated one channel */
|
|
chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
|
|
if (!chans)
|
|
return -ENOMEM;
|
|
|
|
regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
|
|
mbox->mbox_base = devm_ioremap_resource(&pdev->dev, regs);
|
|
if (IS_ERR(mbox->mbox_base))
|
|
return PTR_ERR(mbox->mbox_base);
|
|
|
|
/* Check is it a sender or receiver? */
|
|
mbox->is_sender = altera_mbox_is_sender(mbox);
|
|
|
|
mbox->irq = platform_get_irq(pdev, 0);
|
|
if (mbox->irq >= 0)
|
|
mbox->intr_mode = true;
|
|
|
|
mbox->dev = &pdev->dev;
|
|
|
|
/* Hardware supports only one channel. */
|
|
chans[0].con_priv = mbox;
|
|
mbox->controller.dev = mbox->dev;
|
|
mbox->controller.num_chans = 1;
|
|
mbox->controller.chans = chans;
|
|
mbox->controller.ops = &altera_mbox_ops;
|
|
|
|
if (mbox->is_sender) {
|
|
if (mbox->intr_mode) {
|
|
mbox->controller.txdone_irq = true;
|
|
} else {
|
|
mbox->controller.txdone_poll = true;
|
|
mbox->controller.txpoll_period = MBOX_POLLING_MS;
|
|
}
|
|
}
|
|
|
|
ret = mbox_controller_register(&mbox->controller);
|
|
if (ret) {
|
|
dev_err(&pdev->dev, "Register mailbox failed\n");
|
|
goto err;
|
|
}
|
|
|
|
platform_set_drvdata(pdev, mbox);
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
static int altera_mbox_remove(struct platform_device *pdev)
|
|
{
|
|
struct altera_mbox *mbox = platform_get_drvdata(pdev);
|
|
|
|
if (!mbox)
|
|
return -EINVAL;
|
|
|
|
mbox_controller_unregister(&mbox->controller);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id altera_mbox_match[] = {
|
|
{ .compatible = "altr,mailbox-1.0" },
|
|
{ /* Sentinel */ }
|
|
};
|
|
|
|
MODULE_DEVICE_TABLE(of, altera_mbox_match);
|
|
|
|
static struct platform_driver altera_mbox_driver = {
|
|
.probe = altera_mbox_probe,
|
|
.remove = altera_mbox_remove,
|
|
.driver = {
|
|
.name = DRIVER_NAME,
|
|
.of_match_table = altera_mbox_match,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(altera_mbox_driver);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("Altera mailbox specific functions");
|
|
MODULE_AUTHOR("Ley Foon Tan <lftan@altera.com>");
|
|
MODULE_ALIAS("platform:altera-mailbox");
|