238 строки
6.2 KiB
C
238 строки
6.2 KiB
C
/*
|
|
* Meson Watchdog Driver
|
|
*
|
|
* Copyright (c) 2014 Carlo Caione
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/err.h>
|
|
#include <linux/init.h>
|
|
#include <linux/io.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/of.h>
|
|
#include <linux/of_device.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/types.h>
|
|
#include <linux/watchdog.h>
|
|
|
|
#define DRV_NAME "meson_wdt"
|
|
|
|
#define MESON_WDT_TC 0x00
|
|
#define MESON_WDT_DC_RESET (3 << 24)
|
|
|
|
#define MESON_WDT_RESET 0x04
|
|
|
|
#define MESON_WDT_TIMEOUT 30
|
|
#define MESON_WDT_MIN_TIMEOUT 1
|
|
|
|
#define MESON_SEC_TO_TC(s, c) ((s) * (c))
|
|
|
|
static bool nowayout = WATCHDOG_NOWAYOUT;
|
|
static unsigned int timeout;
|
|
|
|
struct meson_wdt_data {
|
|
unsigned int enable;
|
|
unsigned int terminal_count_mask;
|
|
unsigned int count_unit;
|
|
};
|
|
|
|
static struct meson_wdt_data meson6_wdt_data = {
|
|
.enable = BIT(22),
|
|
.terminal_count_mask = 0x3fffff,
|
|
.count_unit = 100000, /* 10 us */
|
|
};
|
|
|
|
static struct meson_wdt_data meson8b_wdt_data = {
|
|
.enable = BIT(19),
|
|
.terminal_count_mask = 0xffff,
|
|
.count_unit = 7812, /* 128 us */
|
|
};
|
|
|
|
struct meson_wdt_dev {
|
|
struct watchdog_device wdt_dev;
|
|
void __iomem *wdt_base;
|
|
const struct meson_wdt_data *data;
|
|
};
|
|
|
|
static int meson_wdt_restart(struct watchdog_device *wdt_dev,
|
|
unsigned long action, void *data)
|
|
{
|
|
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
|
|
u32 tc_reboot = MESON_WDT_DC_RESET;
|
|
|
|
tc_reboot |= meson_wdt->data->enable;
|
|
|
|
while (1) {
|
|
writel(tc_reboot, meson_wdt->wdt_base + MESON_WDT_TC);
|
|
mdelay(5);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int meson_wdt_ping(struct watchdog_device *wdt_dev)
|
|
{
|
|
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
|
|
|
|
writel(0, meson_wdt->wdt_base + MESON_WDT_RESET);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void meson_wdt_change_timeout(struct watchdog_device *wdt_dev,
|
|
unsigned int timeout)
|
|
{
|
|
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
|
|
u32 reg;
|
|
|
|
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
|
|
reg &= ~meson_wdt->data->terminal_count_mask;
|
|
reg |= MESON_SEC_TO_TC(timeout, meson_wdt->data->count_unit);
|
|
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
|
|
}
|
|
|
|
static int meson_wdt_set_timeout(struct watchdog_device *wdt_dev,
|
|
unsigned int timeout)
|
|
{
|
|
wdt_dev->timeout = timeout;
|
|
|
|
meson_wdt_change_timeout(wdt_dev, timeout);
|
|
meson_wdt_ping(wdt_dev);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int meson_wdt_stop(struct watchdog_device *wdt_dev)
|
|
{
|
|
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
|
|
u32 reg;
|
|
|
|
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
|
|
reg &= ~meson_wdt->data->enable;
|
|
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int meson_wdt_start(struct watchdog_device *wdt_dev)
|
|
{
|
|
struct meson_wdt_dev *meson_wdt = watchdog_get_drvdata(wdt_dev);
|
|
u32 reg;
|
|
|
|
meson_wdt_change_timeout(wdt_dev, meson_wdt->wdt_dev.timeout);
|
|
meson_wdt_ping(wdt_dev);
|
|
|
|
reg = readl(meson_wdt->wdt_base + MESON_WDT_TC);
|
|
reg |= meson_wdt->data->enable;
|
|
writel(reg, meson_wdt->wdt_base + MESON_WDT_TC);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info meson_wdt_info = {
|
|
.identity = DRV_NAME,
|
|
.options = WDIOF_SETTIMEOUT |
|
|
WDIOF_KEEPALIVEPING |
|
|
WDIOF_MAGICCLOSE,
|
|
};
|
|
|
|
static const struct watchdog_ops meson_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = meson_wdt_start,
|
|
.stop = meson_wdt_stop,
|
|
.ping = meson_wdt_ping,
|
|
.set_timeout = meson_wdt_set_timeout,
|
|
.restart = meson_wdt_restart,
|
|
};
|
|
|
|
static const struct of_device_id meson_wdt_dt_ids[] = {
|
|
{ .compatible = "amlogic,meson6-wdt", .data = &meson6_wdt_data },
|
|
{ .compatible = "amlogic,meson8-wdt", .data = &meson6_wdt_data },
|
|
{ .compatible = "amlogic,meson8b-wdt", .data = &meson8b_wdt_data },
|
|
{ .compatible = "amlogic,meson8m2-wdt", .data = &meson8b_wdt_data },
|
|
{ /* sentinel */ }
|
|
};
|
|
MODULE_DEVICE_TABLE(of, meson_wdt_dt_ids);
|
|
|
|
static int meson_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct resource *res;
|
|
struct meson_wdt_dev *meson_wdt;
|
|
const struct of_device_id *of_id;
|
|
int err;
|
|
|
|
meson_wdt = devm_kzalloc(&pdev->dev, sizeof(*meson_wdt), GFP_KERNEL);
|
|
if (!meson_wdt)
|
|
return -ENOMEM;
|
|
|
|
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
|
|
meson_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res);
|
|
if (IS_ERR(meson_wdt->wdt_base))
|
|
return PTR_ERR(meson_wdt->wdt_base);
|
|
|
|
of_id = of_match_device(meson_wdt_dt_ids, &pdev->dev);
|
|
if (!of_id) {
|
|
dev_err(&pdev->dev, "Unable to initialize WDT data\n");
|
|
return -ENODEV;
|
|
}
|
|
meson_wdt->data = of_id->data;
|
|
|
|
meson_wdt->wdt_dev.parent = &pdev->dev;
|
|
meson_wdt->wdt_dev.info = &meson_wdt_info;
|
|
meson_wdt->wdt_dev.ops = &meson_wdt_ops;
|
|
meson_wdt->wdt_dev.max_timeout =
|
|
meson_wdt->data->terminal_count_mask / meson_wdt->data->count_unit;
|
|
meson_wdt->wdt_dev.min_timeout = MESON_WDT_MIN_TIMEOUT;
|
|
meson_wdt->wdt_dev.timeout = min_t(unsigned int,
|
|
MESON_WDT_TIMEOUT,
|
|
meson_wdt->wdt_dev.max_timeout);
|
|
|
|
watchdog_set_drvdata(&meson_wdt->wdt_dev, meson_wdt);
|
|
|
|
watchdog_init_timeout(&meson_wdt->wdt_dev, timeout, &pdev->dev);
|
|
watchdog_set_nowayout(&meson_wdt->wdt_dev, nowayout);
|
|
watchdog_set_restart_priority(&meson_wdt->wdt_dev, 128);
|
|
|
|
meson_wdt_stop(&meson_wdt->wdt_dev);
|
|
|
|
watchdog_stop_on_reboot(&meson_wdt->wdt_dev);
|
|
err = devm_watchdog_register_device(&pdev->dev, &meson_wdt->wdt_dev);
|
|
if (err)
|
|
return err;
|
|
|
|
dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)",
|
|
meson_wdt->wdt_dev.timeout, nowayout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver meson_wdt_driver = {
|
|
.probe = meson_wdt_probe,
|
|
.driver = {
|
|
.name = DRV_NAME,
|
|
.of_match_table = meson_wdt_dt_ids,
|
|
},
|
|
};
|
|
|
|
module_platform_driver(meson_wdt_driver);
|
|
|
|
module_param(timeout, uint, 0);
|
|
MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds");
|
|
|
|
module_param(nowayout, bool, 0);
|
|
MODULE_PARM_DESC(nowayout,
|
|
"Watchdog cannot be stopped once started (default="
|
|
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
|
|
MODULE_DESCRIPTION("Meson Watchdog Timer Driver");
|