linux-imx

// SPDX-License-Identifier: GPL-2.0+

/*

 * Watchdog driver for the wm831x PMICs

 *

 * Copyright (C) 2009 Wolfson Microelectronics

 */

​

#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);