168 lines
4.2 KiB
C
168 lines
4.2 KiB
C
/*
|
|
* MOXA ART SoCs watchdog driver.
|
|
*
|
|
* Copyright (C) 2013 Jonas Jensen
|
|
*
|
|
* Jonas Jensen <jonas.jensen@gmail.com>
|
|
*
|
|
* This file is licensed under the terms of the GNU General Public
|
|
* License version 2. This program is licensed "as is" without any
|
|
* warranty of any kind, whether express or implied.
|
|
*/
|
|
|
|
#include <linux/clk.h>
|
|
#include <linux/io.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/err.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/platform_device.h>
|
|
#include <linux/watchdog.h>
|
|
#include <linux/moduleparam.h>
|
|
|
|
#define REG_COUNT 0x4
|
|
#define REG_MODE 0x8
|
|
#define REG_ENABLE 0xC
|
|
|
|
struct moxart_wdt_dev {
|
|
struct watchdog_device dev;
|
|
void __iomem *base;
|
|
unsigned int clock_frequency;
|
|
};
|
|
|
|
static int heartbeat;
|
|
|
|
static int moxart_wdt_restart(struct watchdog_device *wdt_dev,
|
|
unsigned long action, void *data)
|
|
{
|
|
struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
|
|
|
|
writel(1, moxart_wdt->base + REG_COUNT);
|
|
writel(0x5ab9, moxart_wdt->base + REG_MODE);
|
|
writel(0x03, moxart_wdt->base + REG_ENABLE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int moxart_wdt_stop(struct watchdog_device *wdt_dev)
|
|
{
|
|
struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
|
|
|
|
writel(0, moxart_wdt->base + REG_ENABLE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int moxart_wdt_start(struct watchdog_device *wdt_dev)
|
|
{
|
|
struct moxart_wdt_dev *moxart_wdt = watchdog_get_drvdata(wdt_dev);
|
|
|
|
writel(moxart_wdt->clock_frequency * wdt_dev->timeout,
|
|
moxart_wdt->base + REG_COUNT);
|
|
writel(0x5ab9, moxart_wdt->base + REG_MODE);
|
|
writel(0x03, moxart_wdt->base + REG_ENABLE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int moxart_wdt_set_timeout(struct watchdog_device *wdt_dev,
|
|
unsigned int timeout)
|
|
{
|
|
wdt_dev->timeout = timeout;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct watchdog_info moxart_wdt_info = {
|
|
.identity = "moxart-wdt",
|
|
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
|
|
WDIOF_MAGICCLOSE,
|
|
};
|
|
|
|
static const struct watchdog_ops moxart_wdt_ops = {
|
|
.owner = THIS_MODULE,
|
|
.start = moxart_wdt_start,
|
|
.stop = moxart_wdt_stop,
|
|
.set_timeout = moxart_wdt_set_timeout,
|
|
.restart = moxart_wdt_restart,
|
|
};
|
|
|
|
static int moxart_wdt_probe(struct platform_device *pdev)
|
|
{
|
|
struct moxart_wdt_dev *moxart_wdt;
|
|
struct device *dev = &pdev->dev;
|
|
struct clk *clk;
|
|
int err;
|
|
unsigned int max_timeout;
|
|
bool nowayout = WATCHDOG_NOWAYOUT;
|
|
|
|
moxart_wdt = devm_kzalloc(dev, sizeof(*moxart_wdt), GFP_KERNEL);
|
|
if (!moxart_wdt)
|
|
return -ENOMEM;
|
|
|
|
platform_set_drvdata(pdev, moxart_wdt);
|
|
|
|
moxart_wdt->base = devm_platform_ioremap_resource(pdev, 0);
|
|
if (IS_ERR(moxart_wdt->base))
|
|
return PTR_ERR(moxart_wdt->base);
|
|
|
|
clk = devm_clk_get(dev, NULL);
|
|
if (IS_ERR(clk)) {
|
|
pr_err("%s: of_clk_get failed\n", __func__);
|
|
return PTR_ERR(clk);
|
|
}
|
|
|
|
moxart_wdt->clock_frequency = clk_get_rate(clk);
|
|
if (moxart_wdt->clock_frequency == 0) {
|
|
pr_err("%s: incorrect clock frequency\n", __func__);
|
|
return -EINVAL;
|
|
}
|
|
|
|
max_timeout = UINT_MAX / moxart_wdt->clock_frequency;
|
|
|
|
moxart_wdt->dev.info = &moxart_wdt_info;
|
|
moxart_wdt->dev.ops = &moxart_wdt_ops;
|
|
moxart_wdt->dev.timeout = max_timeout;
|
|
moxart_wdt->dev.min_timeout = 1;
|
|
moxart_wdt->dev.max_timeout = max_timeout;
|
|
moxart_wdt->dev.parent = dev;
|
|
|
|
watchdog_init_timeout(&moxart_wdt->dev, heartbeat, dev);
|
|
watchdog_set_nowayout(&moxart_wdt->dev, nowayout);
|
|
watchdog_set_restart_priority(&moxart_wdt->dev, 128);
|
|
|
|
watchdog_set_drvdata(&moxart_wdt->dev, moxart_wdt);
|
|
|
|
watchdog_stop_on_unregister(&moxart_wdt->dev);
|
|
err = devm_watchdog_register_device(dev, &moxart_wdt->dev);
|
|
if (err)
|
|
return err;
|
|
|
|
dev_dbg(dev, "Watchdog enabled (heartbeat=%d sec, nowayout=%d)\n",
|
|
moxart_wdt->dev.timeout, nowayout);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct of_device_id moxart_watchdog_match[] = {
|
|
{ .compatible = "moxa,moxart-watchdog" },
|
|
{ },
|
|
};
|
|
MODULE_DEVICE_TABLE(of, moxart_watchdog_match);
|
|
|
|
static struct platform_driver moxart_wdt_driver = {
|
|
.probe = moxart_wdt_probe,
|
|
.driver = {
|
|
.name = "moxart-watchdog",
|
|
.of_match_table = moxart_watchdog_match,
|
|
},
|
|
};
|
|
module_platform_driver(moxart_wdt_driver);
|
|
|
|
module_param(heartbeat, int, 0);
|
|
MODULE_PARM_DESC(heartbeat, "Watchdog heartbeat in seconds");
|
|
|
|
MODULE_DESCRIPTION("MOXART watchdog driver");
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_AUTHOR("Jonas Jensen <jonas.jensen@gmail.com>");
|