linux/drivers/watchdog/da9055_wdt.c
Guenter Roeck 89f944c0f9 watchdog: da9055_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;'
- Drop assignments to otherwise unused variables
- Drop remove function
- Drop platform_set_drvdata()
- Use devm_watchdog_register_driver() to register watchdog device

Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00

174 lines
4.3 KiB
C

/*
* System monitoring driver for DA9055 PMICs.
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: David Dajun Chen <dchen@diasemi.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/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/watchdog.h>
#include <linux/delay.h>
#include <linux/mfd/da9055/core.h>
#include <linux/mfd/da9055/reg.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) ")");
#define DA9055_DEF_TIMEOUT 4
#define DA9055_TWDMIN 256
struct da9055_wdt_data {
struct watchdog_device wdt;
struct da9055 *da9055;
};
static const struct {
u8 reg_val;
int user_time; /* In seconds */
} da9055_wdt_maps[] = {
{ 0, 0 },
{ 1, 2 },
{ 2, 4 },
{ 3, 8 },
{ 4, 16 },
{ 5, 32 },
{ 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */
{ 6, 65 },
{ 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */
{ 7, 131 },
};
static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9055 *da9055 = driver_data->da9055;
int ret, i;
for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++)
if (da9055_wdt_maps[i].user_time == timeout)
break;
if (i == ARRAY_SIZE(da9055_wdt_maps))
ret = -EINVAL;
else
ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,
DA9055_TWDSCALE_MASK,
da9055_wdt_maps[i].reg_val <<
DA9055_TWDSCALE_SHIFT);
if (ret < 0) {
dev_err(da9055->dev,
"Failed to update timescale bit, %d\n", ret);
return ret;
}
wdt_dev->timeout = timeout;
return 0;
}
static int da9055_wdt_ping(struct watchdog_device *wdt_dev)
{
struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9055 *da9055 = driver_data->da9055;
/*
* We have a minimum time for watchdog window called TWDMIN. A write
* to the watchdog before this elapsed time will cause an error.
*/
mdelay(DA9055_TWDMIN);
/* Reset the watchdog timer */
return da9055_reg_update(da9055, DA9055_REG_CONTROL_E,
DA9055_WATCHDOG_MASK, 1);
}
static int da9055_wdt_start(struct watchdog_device *wdt_dev)
{
return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
}
static int da9055_wdt_stop(struct watchdog_device *wdt_dev)
{
return da9055_wdt_set_timeout(wdt_dev, 0);
}
static const struct watchdog_info da9055_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9055 Watchdog",
};
static const struct watchdog_ops da9055_wdt_ops = {
.owner = THIS_MODULE,
.start = da9055_wdt_start,
.stop = da9055_wdt_stop,
.ping = da9055_wdt_ping,
.set_timeout = da9055_wdt_set_timeout,
};
static int da9055_wdt_probe(struct platform_device *pdev)
{
struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
struct da9055_wdt_data *driver_data;
struct watchdog_device *da9055_wdt;
int ret;
driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
GFP_KERNEL);
if (!driver_data)
return -ENOMEM;
driver_data->da9055 = da9055;
da9055_wdt = &driver_data->wdt;
da9055_wdt->timeout = DA9055_DEF_TIMEOUT;
da9055_wdt->info = &da9055_wdt_info;
da9055_wdt->ops = &da9055_wdt_ops;
da9055_wdt->parent = &pdev->dev;
watchdog_set_nowayout(da9055_wdt, nowayout);
watchdog_set_drvdata(da9055_wdt, driver_data);
ret = da9055_wdt_stop(da9055_wdt);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to stop watchdog, %d\n", ret);
return ret;
}
ret = devm_watchdog_register_device(&pdev->dev, &driver_data->wdt);
if (ret != 0)
dev_err(da9055->dev, "watchdog_register_device() failed: %d\n",
ret);
return ret;
}
static struct platform_driver da9055_wdt_driver = {
.probe = da9055_wdt_probe,
.driver = {
.name = "da9055-watchdog",
},
};
module_platform_driver(da9055_wdt_driver);
MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
MODULE_DESCRIPTION("DA9055 watchdog");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9055-watchdog");