LXR linux/drivers/watchdog/twl4030

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Copyright (C) Nokia Corporation
   4 *
   5 * Written by Timo Kokkonen <timo.t.kokkonen at nokia.com>
   6 */
   7
   8#include <linux/module.h>
   9#include <linux/types.h>
  10#include <linux/slab.h>
  11#include <linux/kernel.h>
  12#include <linux/watchdog.h>
  13#include <linux/platform_device.h>
  14#include <linux/mfd/twl.h>
  15
  16#define TWL4030_WATCHDOG_CFG_REG_OFFS   0x3
  17
  18static bool nowayout = WATCHDOG_NOWAYOUT;
  19module_param(nowayout, bool, 0);
  20MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
  21        "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  22
  23static int twl4030_wdt_write(unsigned char val)
  24{
  25        return twl_i2c_write_u8(TWL_MODULE_PM_RECEIVER, val,
  26                                        TWL4030_WATCHDOG_CFG_REG_OFFS);
  27}
  28
  29static int twl4030_wdt_start(struct watchdog_device *wdt)
  30{
  31        return twl4030_wdt_write(wdt->timeout + 1);
  32}
  33
  34static int twl4030_wdt_stop(struct watchdog_device *wdt)
  35{
  36        return twl4030_wdt_write(0);
  37}
  38
  39static int twl4030_wdt_set_timeout(struct watchdog_device *wdt,
  40                                   unsigned int timeout)
  41{
  42        wdt->timeout = timeout;
  43        return 0;
  44}
  45
  46static const struct watchdog_info twl4030_wdt_info = {
  47        .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
  48        .identity = "TWL4030 Watchdog",
  49};
  50
  51static const struct watchdog_ops twl4030_wdt_ops = {
  52        .owner          = THIS_MODULE,
  53        .start          = twl4030_wdt_start,
  54        .stop           = twl4030_wdt_stop,
  55        .set_timeout    = twl4030_wdt_set_timeout,
  56};
  57
  58static int twl4030_wdt_probe(struct platform_device *pdev)
  59{
  60        struct device *dev = &pdev->dev;
  61        struct watchdog_device *wdt;
  62
  63        wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
  64        if (!wdt)
  65                return -ENOMEM;
  66
  67        wdt->info               = &twl4030_wdt_info;
  68        wdt->ops                = &twl4030_wdt_ops;
  69        wdt->status             = 0;
  70        wdt->timeout            = 30;
  71        wdt->min_timeout        = 1;
  72        wdt->max_timeout        = 30;
  73        wdt->parent = dev;
  74
  75        watchdog_set_nowayout(wdt, nowayout);
  76        platform_set_drvdata(pdev, wdt);
  77
  78        twl4030_wdt_stop(wdt);
  79
  80        return devm_watchdog_register_device(dev, wdt);
  81}
  82
  83#ifdef CONFIG_PM
  84static int twl4030_wdt_suspend(struct platform_device *pdev, pm_message_t state)
  85{
  86        struct watchdog_device *wdt = platform_get_drvdata(pdev);
  87        if (watchdog_active(wdt))
  88                return twl4030_wdt_stop(wdt);
  89
  90        return 0;
  91}
  92
  93static int twl4030_wdt_resume(struct platform_device *pdev)
  94{
  95        struct watchdog_device *wdt = platform_get_drvdata(pdev);
  96        if (watchdog_active(wdt))
  97                return twl4030_wdt_start(wdt);
  98
  99        return 0;
 100}
 101#else
 102#define twl4030_wdt_suspend        NULL
 103#define twl4030_wdt_resume         NULL
 104#endif
 105
 106static const struct of_device_id twl_wdt_of_match[] = {
 107        { .compatible = "ti,twl4030-wdt", },
 108        { },
 109};
 110MODULE_DEVICE_TABLE(of, twl_wdt_of_match);
 111
 112static struct platform_driver twl4030_wdt_driver = {
 113        .probe          = twl4030_wdt_probe,
 114        .suspend        = twl4030_wdt_suspend,
 115        .resume         = twl4030_wdt_resume,
 116        .driver         = {
 117                .name           = "twl4030_wdt",
 118                .of_match_table = twl_wdt_of_match,
 119        },
 120};
 121
 122module_platform_driver(twl4030_wdt_driver);
 123
 124MODULE_AUTHOR("Nokia Corporation");
 125MODULE_LICENSE("GPL");
 126MODULE_ALIAS("platform:twl4030_wdt");
 127
 128