linux/drivers/watchdog/loongson1_wdt.c
Guenter Roeck fd56d6c9a2 watchdog: loongson1_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 unnecessary braces around conditional return statements
- Drop empty remove function
- Use devm_add_action_or_reset() for calls to clk_disable_unprepare
- Introduce local variable 'struct device *dev' and use it instead of
  dereferencing it repeatedly
- Use devm_watchdog_register_driver() to register watchdog device

Cc: Keguang Zhang <keguang.zhang@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-05-05 21:02:36 +02:00

163 lines
3.8 KiB
C

/*
* Copyright (c) 2016 Yang Ling <gnaygnil@gmail.com>
*
* 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/module.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <loongson1.h>
#define DEFAULT_HEARTBEAT 30
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
static unsigned int heartbeat;
module_param(heartbeat, uint, 0444);
struct ls1x_wdt_drvdata {
void __iomem *base;
struct clk *clk;
unsigned long clk_rate;
struct watchdog_device wdt;
};
static int ls1x_wdt_ping(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x1, drvdata->base + WDT_SET);
return 0;
}
static int ls1x_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
unsigned int max_hw_heartbeat = wdt_dev->max_hw_heartbeat_ms / 1000;
unsigned int counts;
wdt_dev->timeout = timeout;
counts = drvdata->clk_rate * min(timeout, max_hw_heartbeat);
writel(counts, drvdata->base + WDT_TIMER);
return 0;
}
static int ls1x_wdt_start(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x1, drvdata->base + WDT_EN);
return 0;
}
static int ls1x_wdt_stop(struct watchdog_device *wdt_dev)
{
struct ls1x_wdt_drvdata *drvdata = watchdog_get_drvdata(wdt_dev);
writel(0x0, drvdata->base + WDT_EN);
return 0;
}
static const struct watchdog_info ls1x_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "Loongson1 Watchdog",
};
static const struct watchdog_ops ls1x_wdt_ops = {
.owner = THIS_MODULE,
.start = ls1x_wdt_start,
.stop = ls1x_wdt_stop,
.ping = ls1x_wdt_ping,
.set_timeout = ls1x_wdt_set_timeout,
};
static void ls1x_clk_disable_unprepare(void *data)
{
clk_disable_unprepare(data);
}
static int ls1x_wdt_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct ls1x_wdt_drvdata *drvdata;
struct watchdog_device *ls1x_wdt;
unsigned long clk_rate;
int err;
drvdata = devm_kzalloc(dev, sizeof(*drvdata), GFP_KERNEL);
if (!drvdata)
return -ENOMEM;
drvdata->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(drvdata->base))
return PTR_ERR(drvdata->base);
drvdata->clk = devm_clk_get(dev, pdev->name);
if (IS_ERR(drvdata->clk))
return PTR_ERR(drvdata->clk);
err = clk_prepare_enable(drvdata->clk);
if (err) {
dev_err(dev, "clk enable failed\n");
return err;
}
err = devm_add_action_or_reset(dev, ls1x_clk_disable_unprepare,
drvdata->clk);
if (err)
return err;
clk_rate = clk_get_rate(drvdata->clk);
if (!clk_rate)
return -EINVAL;
drvdata->clk_rate = clk_rate;
ls1x_wdt = &drvdata->wdt;
ls1x_wdt->info = &ls1x_wdt_info;
ls1x_wdt->ops = &ls1x_wdt_ops;
ls1x_wdt->timeout = DEFAULT_HEARTBEAT;
ls1x_wdt->min_timeout = 1;
ls1x_wdt->max_hw_heartbeat_ms = U32_MAX / clk_rate * 1000;
ls1x_wdt->parent = dev;
watchdog_init_timeout(ls1x_wdt, heartbeat, dev);
watchdog_set_nowayout(ls1x_wdt, nowayout);
watchdog_set_drvdata(ls1x_wdt, drvdata);
err = devm_watchdog_register_device(dev, &drvdata->wdt);
if (err) {
dev_err(dev, "failed to register watchdog device\n");
return err;
}
platform_set_drvdata(pdev, drvdata);
dev_info(dev, "Loongson1 Watchdog driver registered\n");
return 0;
}
static struct platform_driver ls1x_wdt_driver = {
.probe = ls1x_wdt_probe,
.driver = {
.name = "ls1x-wdt",
},
};
module_platform_driver(ls1x_wdt_driver);
MODULE_AUTHOR("Yang Ling <gnaygnil@gmail.com>");
MODULE_DESCRIPTION("Loongson1 Watchdog Driver");
MODULE_LICENSE("GPL");