linux/drivers/watchdog/moxart_wdt.c
Guenter Roeck 615e40ad40 watchdog: moxart_wdt: Convert to use device managed functions and other improvements
Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.
Other improvements as listed below.

The conversion was done automatically with coccinelle using the
following semantic patches. The semantic patches and the scripts
used to generate this commit log are available at
https://github.com/groeck/coccinelle-patches

- Drop assignments to otherwise unused variables
- Drop empty remove function
- Replace 'of_clk_get(np, 0)' with 'devm_clk_get(dev, NULL)'
- Use local variable 'struct device *dev' consistently
- Replace stop on remove with call to watchdog_stop_on_unregister()
- Use devm_watchdog_register_driver() to register watchdog device

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-05 21:02:24 +02:00

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>");