mirror of
https://github.com/torvalds/linux.git
synced 2024-11-13 23:51:39 +00:00
f5e2eeb9ff
Use the devm_platform_ioremap_resource() helper instead of calling platform_get_resource() and devm_ioremap_resource() separately Signed-off-by: Cai Huoqing <caihuoqing@baidu.com> Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>
320 lines
8.6 KiB
C
320 lines
8.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
//
|
|
// Copyright (c) 2017-2019 Samuel Holland <samuel@sholland.org>
|
|
|
|
#include <linux/bitops.h>
|
|
#include <linux/clk.h>
|
|
#include <linux/device.h>
|
|
#include <linux/err.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/of_irq.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/reset.h>
|
|
#include <linux/spinlock.h>
|
|
|
|
#define NUM_CHANS 8
|
|
|
|
#define CTRL_REG(n) (0x0000 + 0x4 * ((n) / 4))
|
|
#define CTRL_RX(n) BIT(0 + 8 * ((n) % 4))
|
|
#define CTRL_TX(n) BIT(4 + 8 * ((n) % 4))
|
|
|
|
#define REMOTE_IRQ_EN_REG 0x0040
|
|
#define REMOTE_IRQ_STAT_REG 0x0050
|
|
#define LOCAL_IRQ_EN_REG 0x0060
|
|
#define LOCAL_IRQ_STAT_REG 0x0070
|
|
|
|
#define RX_IRQ(n) BIT(0 + 2 * (n))
|
|
#define RX_IRQ_MASK 0x5555
|
|
#define TX_IRQ(n) BIT(1 + 2 * (n))
|
|
#define TX_IRQ_MASK 0xaaaa
|
|
|
|
#define FIFO_STAT_REG(n) (0x0100 + 0x4 * (n))
|
|
#define FIFO_STAT_MASK GENMASK(0, 0)
|
|
|
|
#define MSG_STAT_REG(n) (0x0140 + 0x4 * (n))
|
|
#define MSG_STAT_MASK GENMASK(2, 0)
|
|
|
|
#define MSG_DATA_REG(n) (0x0180 + 0x4 * (n))
|
|
|
|
#define mbox_dbg(mbox, ...) dev_dbg((mbox)->controller.dev, __VA_ARGS__)
|
|
|
|
struct sun6i_msgbox {
|
|
struct mbox_controller controller;
|
|
struct clk *clk;
|
|
spinlock_t lock;
|
|
void __iomem *regs;
|
|
};
|
|
|
|
static bool sun6i_msgbox_last_tx_done(struct mbox_chan *chan);
|
|
static bool sun6i_msgbox_peek_data(struct mbox_chan *chan);
|
|
|
|
static inline int channel_number(struct mbox_chan *chan)
|
|
{
|
|
return chan - chan->mbox->chans;
|
|
}
|
|
|
|
static inline struct sun6i_msgbox *to_sun6i_msgbox(struct mbox_chan *chan)
|
|
{
|
|
return chan->con_priv;
|
|
}
|
|
|
|
static irqreturn_t sun6i_msgbox_irq(int irq, void *dev_id)
|
|
{
|
|
struct sun6i_msgbox *mbox = dev_id;
|
|
uint32_t status;
|
|
int n;
|
|
|
|
/* Only examine channels that are currently enabled. */
|
|
status = readl(mbox->regs + LOCAL_IRQ_EN_REG) &
|
|
readl(mbox->regs + LOCAL_IRQ_STAT_REG);
|
|
|
|
if (!(status & RX_IRQ_MASK))
|
|
return IRQ_NONE;
|
|
|
|
for (n = 0; n < NUM_CHANS; ++n) {
|
|
struct mbox_chan *chan = &mbox->controller.chans[n];
|
|
|
|
if (!(status & RX_IRQ(n)))
|
|
continue;
|
|
|
|
while (sun6i_msgbox_peek_data(chan)) {
|
|
uint32_t msg = readl(mbox->regs + MSG_DATA_REG(n));
|
|
|
|
mbox_dbg(mbox, "Channel %d received 0x%08x\n", n, msg);
|
|
mbox_chan_received_data(chan, &msg);
|
|
}
|
|
|
|
/* The IRQ can be cleared only once the FIFO is empty. */
|
|
writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static int sun6i_msgbox_send_data(struct mbox_chan *chan, void *data)
|
|
{
|
|
struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
|
|
int n = channel_number(chan);
|
|
uint32_t msg = *(uint32_t *)data;
|
|
|
|
/* Using a channel backwards gets the hardware into a bad state. */
|
|
if (WARN_ON_ONCE(!(readl(mbox->regs + CTRL_REG(n)) & CTRL_TX(n))))
|
|
return 0;
|
|
|
|
writel(msg, mbox->regs + MSG_DATA_REG(n));
|
|
mbox_dbg(mbox, "Channel %d sent 0x%08x\n", n, msg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int sun6i_msgbox_startup(struct mbox_chan *chan)
|
|
{
|
|
struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
|
|
int n = channel_number(chan);
|
|
|
|
/* The coprocessor is responsible for setting channel directions. */
|
|
if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
|
|
/* Flush the receive FIFO. */
|
|
while (sun6i_msgbox_peek_data(chan))
|
|
readl(mbox->regs + MSG_DATA_REG(n));
|
|
writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
|
|
|
|
/* Enable the receive IRQ. */
|
|
spin_lock(&mbox->lock);
|
|
writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) | RX_IRQ(n),
|
|
mbox->regs + LOCAL_IRQ_EN_REG);
|
|
spin_unlock(&mbox->lock);
|
|
}
|
|
|
|
mbox_dbg(mbox, "Channel %d startup complete\n", n);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void sun6i_msgbox_shutdown(struct mbox_chan *chan)
|
|
{
|
|
struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
|
|
int n = channel_number(chan);
|
|
|
|
if (readl(mbox->regs + CTRL_REG(n)) & CTRL_RX(n)) {
|
|
/* Disable the receive IRQ. */
|
|
spin_lock(&mbox->lock);
|
|
writel(readl(mbox->regs + LOCAL_IRQ_EN_REG) & ~RX_IRQ(n),
|
|
mbox->regs + LOCAL_IRQ_EN_REG);
|
|
spin_unlock(&mbox->lock);
|
|
|
|
/* Attempt to flush the FIFO until the IRQ is cleared. */
|
|
do {
|
|
while (sun6i_msgbox_peek_data(chan))
|
|
readl(mbox->regs + MSG_DATA_REG(n));
|
|
writel(RX_IRQ(n), mbox->regs + LOCAL_IRQ_STAT_REG);
|
|
} while (readl(mbox->regs + LOCAL_IRQ_STAT_REG) & RX_IRQ(n));
|
|
}
|
|
|
|
mbox_dbg(mbox, "Channel %d shutdown complete\n", n);
|
|
}
|
|
|
|
static bool sun6i_msgbox_last_tx_done(struct mbox_chan *chan)
|
|
{
|
|
struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
|
|
int n = channel_number(chan);
|
|
|
|
/*
|
|
* The hardware allows snooping on the remote user's IRQ statuses.
|
|
* We consider a message to be acknowledged only once the receive IRQ
|
|
* for that channel is cleared. Since the receive IRQ for a channel
|
|
* cannot be cleared until the FIFO for that channel is empty, this
|
|
* ensures that the message has actually been read. It also gives the
|
|
* recipient an opportunity to perform minimal processing before
|
|
* acknowledging the message.
|
|
*/
|
|
return !(readl(mbox->regs + REMOTE_IRQ_STAT_REG) & RX_IRQ(n));
|
|
}
|
|
|
|
static bool sun6i_msgbox_peek_data(struct mbox_chan *chan)
|
|
{
|
|
struct sun6i_msgbox *mbox = to_sun6i_msgbox(chan);
|
|
int n = channel_number(chan);
|
|
|
|
return readl(mbox->regs + MSG_STAT_REG(n)) & MSG_STAT_MASK;
|
|
}
|
|
|
|
static const struct mbox_chan_ops sun6i_msgbox_chan_ops = {
|
|
.send_data = sun6i_msgbox_send_data,
|
|
.startup = sun6i_msgbox_startup,
|
|
.shutdown = sun6i_msgbox_shutdown,
|
|
.last_tx_done = sun6i_msgbox_last_tx_done,
|
|
.peek_data = sun6i_msgbox_peek_data,
|
|
};
|
|
|
|
static int sun6i_msgbox_probe(struct platform_device *pdev)
|
|
{
|
|
struct device *dev = &pdev->dev;
|
|
struct mbox_chan *chans;
|
|
struct reset_control *reset;
|
|
struct sun6i_msgbox *mbox;
|
|
int i, ret;
|
|
|
|
mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
|
|
if (!mbox)
|
|
return -ENOMEM;
|
|
|
|
chans = devm_kcalloc(dev, NUM_CHANS, sizeof(*chans), GFP_KERNEL);
|
|
if (!chans)
|
|
return -ENOMEM;
|
|
|
|
for (i = 0; i < NUM_CHANS; ++i)
|
|
chans[i].con_priv = mbox;
|
|
|
|
mbox->clk = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(mbox->clk)) {
|
|
ret = PTR_ERR(mbox->clk);
|
|
dev_err(dev, "Failed to get clock: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
ret = clk_prepare_enable(mbox->clk);
|
|
if (ret) {
|
|
dev_err(dev, "Failed to enable clock: %d\n", ret);
|
|
return ret;
|
|
}
|
|
|
|
reset = devm_reset_control_get_exclusive(dev, NULL);
|
|
if (IS_ERR(reset)) {
|
|
ret = PTR_ERR(reset);
|
|
dev_err(dev, "Failed to get reset control: %d\n", ret);
|
|
goto err_disable_unprepare;
|
|
}
|
|
|
|
/*
|
|
* NOTE: We rely on platform firmware to preconfigure the channel
|
|
* directions, and we share this hardware block with other firmware
|
|
* that runs concurrently with Linux (e.g. a trusted monitor).
|
|
*
|
|
* Therefore, we do *not* assert the reset line if probing fails or
|
|
* when removing the device.
|
|
*/
|
|
ret = reset_control_deassert(reset);
|
|
if (ret) {
|
|
dev_err(dev, "Failed to deassert reset: %d\n", ret);
|
|
goto err_disable_unprepare;
|
|
}
|
|
|
|
mbox->regs = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(mbox->regs)) {
|
|
ret = PTR_ERR(mbox->regs);
|
|
dev_err(dev, "Failed to map MMIO resource: %d\n", ret);
|
|
goto err_disable_unprepare;
|
|
}
|
|
|
|
/* Disable all IRQs for this end of the msgbox. */
|
|
writel(0, mbox->regs + LOCAL_IRQ_EN_REG);
|
|
|
|
ret = devm_request_irq(dev, irq_of_parse_and_map(dev->of_node, 0),
|
|
sun6i_msgbox_irq, 0, dev_name(dev), mbox);
|
|
if (ret) {
|
|
dev_err(dev, "Failed to register IRQ handler: %d\n", ret);
|
|
goto err_disable_unprepare;
|
|
}
|
|
|
|
mbox->controller.dev = dev;
|
|
mbox->controller.ops = &sun6i_msgbox_chan_ops;
|
|
mbox->controller.chans = chans;
|
|
mbox->controller.num_chans = NUM_CHANS;
|
|
mbox->controller.txdone_irq = false;
|
|
mbox->controller.txdone_poll = true;
|
|
mbox->controller.txpoll_period = 5;
|
|
|
|
spin_lock_init(&mbox->lock);
|
|
platform_set_drvdata(pdev, mbox);
|
|
|
|
ret = mbox_controller_register(&mbox->controller);
|
|
if (ret) {
|
|
dev_err(dev, "Failed to register controller: %d\n", ret);
|
|
goto err_disable_unprepare;
|
|
}
|
|
|
|
return 0;
|
|
|
|
err_disable_unprepare:
|
|
clk_disable_unprepare(mbox->clk);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int sun6i_msgbox_remove(struct platform_device *pdev)
|
|
{
|
|
struct sun6i_msgbox *mbox = platform_get_drvdata(pdev);
|
|
|
|
mbox_controller_unregister(&mbox->controller);
|
|
/* See the comment in sun6i_msgbox_probe about the reset line. */
|
|
clk_disable_unprepare(mbox->clk);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id sun6i_msgbox_of_match[] = {
|
|
{ .compatible = "allwinner,sun6i-a31-msgbox", },
|
|
{},
|
|
};
|
|
MODULE_DEVICE_TABLE(of, sun6i_msgbox_of_match);
|
|
|
|
static struct platform_driver sun6i_msgbox_driver = {
|
|
.driver = {
|
|
.name = "sun6i-msgbox",
|
|
.of_match_table = sun6i_msgbox_of_match,
|
|
},
|
|
.probe = sun6i_msgbox_probe,
|
|
.remove = sun6i_msgbox_remove,
|
|
};
|
|
module_platform_driver(sun6i_msgbox_driver);
|
|
|
|
MODULE_AUTHOR("Samuel Holland <samuel@sholland.org>");
|
|
MODULE_DESCRIPTION("Allwinner sun6i/sun8i/sun9i/sun50i Message Box");
|
|
MODULE_LICENSE("GPL v2");
|