linux/drivers/watchdog/da9052_wdt.c
Guenter Roeck 189c049a01 watchdog: da9052_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: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00

207 lines
4.9 KiB
C

/*
* System monitoring driver for DA9052 PMICs.
*
* Copyright(c) 2012 Dialog Semiconductor Ltd.
*
* Author: Anthony Olech <Anthony.Olech@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/delay.h>
#include <linux/uaccess.h>
#include <linux/platform_device.h>
#include <linux/time.h>
#include <linux/watchdog.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/jiffies.h>
#include <linux/mfd/da9052/reg.h>
#include <linux/mfd/da9052/da9052.h>
#define DA9052_DEF_TIMEOUT 4
#define DA9052_TWDMIN 256
struct da9052_wdt_data {
struct watchdog_device wdt;
struct da9052 *da9052;
unsigned long jpast;
};
static const struct {
u8 reg_val;
int time; /* Seconds */
} da9052_wdt_maps[] = {
{ 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 da9052_wdt_set_timeout(struct watchdog_device *wdt_dev,
unsigned int timeout)
{
struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9052 *da9052 = driver_data->da9052;
int ret, i;
/*
* Disable the Watchdog timer before setting
* new time out.
*/
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE, 0);
if (ret < 0) {
dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n",
ret);
return ret;
}
if (timeout) {
/*
* To change the timeout, da9052 needs to
* be disabled for at least 150 us.
*/
udelay(150);
/* Set the desired timeout */
for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++)
if (da9052_wdt_maps[i].time == timeout)
break;
if (i == ARRAY_SIZE(da9052_wdt_maps))
ret = -EINVAL;
else
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE,
da9052_wdt_maps[i].reg_val);
if (ret < 0) {
dev_err(da9052->dev,
"Failed to update timescale bit, %d\n", ret);
return ret;
}
wdt_dev->timeout = timeout;
driver_data->jpast = jiffies;
}
return 0;
}
static int da9052_wdt_start(struct watchdog_device *wdt_dev)
{
return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);
}
static int da9052_wdt_stop(struct watchdog_device *wdt_dev)
{
return da9052_wdt_set_timeout(wdt_dev, 0);
}
static int da9052_wdt_ping(struct watchdog_device *wdt_dev)
{
struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);
struct da9052 *da9052 = driver_data->da9052;
unsigned long msec, jnow = jiffies;
int ret;
/*
* We have a minimum time for watchdog window called TWDMIN. A write
* to the watchdog before this elapsed time should cause an error.
*/
msec = (jnow - driver_data->jpast) * 1000/HZ;
if (msec < DA9052_TWDMIN)
mdelay(msec);
/* Reset the watchdog timer */
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_WATCHDOG, 1 << 7);
if (ret < 0)
return ret;
/*
* FIXME: Reset the watchdog core, in general PMIC
* is supposed to do this
*/
return da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_WATCHDOG, 0 << 7);
}
static const struct watchdog_info da9052_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
.identity = "DA9052 Watchdog",
};
static const struct watchdog_ops da9052_wdt_ops = {
.owner = THIS_MODULE,
.start = da9052_wdt_start,
.stop = da9052_wdt_stop,
.ping = da9052_wdt_ping,
.set_timeout = da9052_wdt_set_timeout,
};
static int da9052_wdt_probe(struct platform_device *pdev)
{
struct da9052 *da9052 = dev_get_drvdata(pdev->dev.parent);
struct da9052_wdt_data *driver_data;
struct watchdog_device *da9052_wdt;
int ret;
driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
GFP_KERNEL);
if (!driver_data)
return -ENOMEM;
driver_data->da9052 = da9052;
da9052_wdt = &driver_data->wdt;
da9052_wdt->timeout = DA9052_DEF_TIMEOUT;
da9052_wdt->info = &da9052_wdt_info;
da9052_wdt->ops = &da9052_wdt_ops;
da9052_wdt->parent = &pdev->dev;
watchdog_set_drvdata(da9052_wdt, driver_data);
ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG,
DA9052_CONTROLD_TWDSCALE, 0);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to disable watchdog bits, %d\n",
ret);
return ret;
}
ret = devm_watchdog_register_device(&pdev->dev, &driver_data->wdt);
if (ret != 0) {
dev_err(da9052->dev, "watchdog_register_device() failed: %d\n",
ret);
return ret;
}
return ret;
}
static struct platform_driver da9052_wdt_driver = {
.probe = da9052_wdt_probe,
.driver = {
.name = "da9052-watchdog",
},
};
module_platform_driver(da9052_wdt_driver);
MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");
MODULE_DESCRIPTION("DA9052 SM Device Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9052-watchdog");