linux/drivers/watchdog/wm831x_wdt.c
Guenter Roeck 30cba9a109 watchdog: wm831x_wdt: Convert to use device managed functions
Use device managed functions to simplify error handling, reduce
source code size, improve readability, and reduce the likelyhood of bugs.

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

- Replace 'goto l; ... l: return e;' with 'return e;'
- Replace 'val = e; return val;' with 'return e;'
- Drop assignments to otherwise unused variables
- Replace 'if (e) { return expr; }' with 'if (e) return expr;'
- Drop remove function
- Drop platform_set_drvdata()
- Use devm_watchdog_register_driver() to register watchdog device

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00

297 lines
7.1 KiB
C

/*
* Watchdog driver for the wm831x PMICs
*
* Copyright (C) 2009 Wolfson Microelectronics
*
* 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
*/
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/uaccess.h>
#include <linux/gpio.h>
#include <linux/mfd/wm831x/core.h>
#include <linux/mfd/wm831x/pdata.h>
#include <linux/mfd/wm831x/watchdog.h>
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
struct wm831x_wdt_drvdata {
struct watchdog_device wdt;
struct wm831x *wm831x;
struct mutex lock;
int update_gpio;
int update_state;
};
/* We can't use the sub-second values here but they're included
* for completeness. */
static struct {
unsigned int time; /* Seconds */
u16 val; /* WDOG_TO value */
} wm831x_wdt_cfgs[] = {
{ 1, 2 },
{ 2, 3 },
{ 4, 4 },
{ 8, 5 },
{ 16, 6 },
{ 32, 7 },
{ 33, 7 }, /* Actually 32.768s so include both, others round down */
};
static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
mutex_lock(&driver_data->lock);
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_ENA, WM831X_WDOG_ENA);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
mutex_lock(&driver_data->lock);
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_ENA, 0);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret;
u16 reg;
mutex_lock(&driver_data->lock);
if (driver_data->update_gpio) {
gpio_set_value_cansleep(driver_data->update_gpio,
driver_data->update_state);
driver_data->update_state = !driver_data->update_state;
ret = 0;
goto out;
}
reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
if (!(reg & WM831X_WDOG_RST_SRC)) {
dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
ret = -EINVAL;
goto out;
}
reg |= WM831X_WDOG_RESET;
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
out:
mutex_unlock(&driver_data->lock);
return ret;
}
static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
struct wm831x *wm831x = driver_data->wm831x;
int ret, i;
for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
if (wm831x_wdt_cfgs[i].time == timeout)
break;
if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
return -EINVAL;
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
WM831X_WDOG_TO_MASK,
wm831x_wdt_cfgs[i].val);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
ret);
}
wdt_dev->timeout = timeout;
return ret;
}
static const struct watchdog_info wm831x_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
.identity = "WM831x Watchdog",
};
static const struct watchdog_ops wm831x_wdt_ops = {
.owner = THIS_MODULE,
.start = wm831x_wdt_start,
.stop = wm831x_wdt_stop,
.ping = wm831x_wdt_ping,
.set_timeout = wm831x_wdt_set_timeout,
};
static int wm831x_wdt_probe(struct platform_device *pdev)
{
struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
struct wm831x_pdata *chip_pdata = dev_get_platdata(pdev->dev.parent);
struct wm831x_watchdog_pdata *pdata;
struct wm831x_wdt_drvdata *driver_data;
struct watchdog_device *wm831x_wdt;
int reg, ret, i;
ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
if (ret < 0) {
dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
ret);
return ret;
}
reg = ret;
if (reg & WM831X_WDOG_DEBUG)
dev_warn(wm831x->dev, "Watchdog is paused\n");
driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
GFP_KERNEL);
if (!driver_data)
return -ENOMEM;
mutex_init(&driver_data->lock);
driver_data->wm831x = wm831x;
wm831x_wdt = &driver_data->wdt;
wm831x_wdt->info = &wm831x_wdt_info;
wm831x_wdt->ops = &wm831x_wdt_ops;
wm831x_wdt->parent = &pdev->dev;
watchdog_set_nowayout(wm831x_wdt, nowayout);
watchdog_set_drvdata(wm831x_wdt, driver_data);
reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
reg &= WM831X_WDOG_TO_MASK;
for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
if (wm831x_wdt_cfgs[i].val == reg)
break;
if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
dev_warn(wm831x->dev,
"Unknown watchdog timeout: %x\n", reg);
else
wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
/* Apply any configuration */
if (chip_pdata)
pdata = chip_pdata->watchdog;
else
pdata = NULL;
if (pdata) {
reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
WM831X_WDOG_RST_SRC);
reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
if (pdata->update_gpio) {
ret = devm_gpio_request_one(&pdev->dev,
pdata->update_gpio,
GPIOF_OUT_INIT_LOW,
"Watchdog update");
if (ret < 0) {
dev_err(wm831x->dev,
"Failed to request update GPIO: %d\n",
ret);
return ret;
}
driver_data->update_gpio = pdata->update_gpio;
/* Make sure the watchdog takes hardware updates */
reg |= WM831X_WDOG_RST_SRC;
}
ret = wm831x_reg_unlock(wm831x);
if (ret == 0) {
ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
wm831x_reg_lock(wm831x);
} else {
dev_err(wm831x->dev,
"Failed to unlock security key: %d\n", ret);
return ret;
}
}
ret = devm_watchdog_register_device(&pdev->dev, &driver_data->wdt);
if (ret != 0) {
dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
ret);
return ret;
}
return 0;
}
static struct platform_driver wm831x_wdt_driver = {
.probe = wm831x_wdt_probe,
.driver = {
.name = "wm831x-watchdog",
},
};
module_platform_driver(wm831x_wdt_driver);
MODULE_AUTHOR("Mark Brown");
MODULE_DESCRIPTION("WM831x Watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:wm831x-watchdog");