LXR linux/drivers/watchdog/ux500

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * Copyright (C) ST-Ericsson SA 2011-2013
   4 *
   5 * Author: Mathieu Poirier <mathieu.poirier@linaro.org> for ST-Ericsson
   6 * Author: Jonas Aaberg <jonas.aberg@stericsson.com> for ST-Ericsson
   7 */
   8
   9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11#include <linux/module.h>
  12#include <linux/kernel.h>
  13#include <linux/moduleparam.h>
  14#include <linux/err.h>
  15#include <linux/uaccess.h>
  16#include <linux/watchdog.h>
  17#include <linux/platform_device.h>
  18#include <linux/platform_data/ux500_wdt.h>
  19
  20#include <linux/mfd/dbx500-prcmu.h>
  21
  22#define WATCHDOG_TIMEOUT 600 /* 10 minutes */
  23
  24#define WATCHDOG_MIN    0
  25#define WATCHDOG_MAX28  268435  /* 28 bit resolution in ms == 268435.455 s */
  26#define WATCHDOG_MAX32  4294967 /* 32 bit resolution in ms == 4294967.295 s */
  27
  28static unsigned int timeout = WATCHDOG_TIMEOUT;
  29module_param(timeout, uint, 0);
  30MODULE_PARM_DESC(timeout,
  31        "Watchdog timeout in seconds. default="
  32                                __MODULE_STRING(WATCHDOG_TIMEOUT) ".");
  33
  34static bool nowayout = WATCHDOG_NOWAYOUT;
  35module_param(nowayout, bool, 0);
  36MODULE_PARM_DESC(nowayout,
  37        "Watchdog cannot be stopped once started (default="
  38                                __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
  39
  40static int ux500_wdt_start(struct watchdog_device *wdd)
  41{
  42        return prcmu_enable_a9wdog(PRCMU_WDOG_ALL);
  43}
  44
  45static int ux500_wdt_stop(struct watchdog_device *wdd)
  46{
  47        return prcmu_disable_a9wdog(PRCMU_WDOG_ALL);
  48}
  49
  50static int ux500_wdt_keepalive(struct watchdog_device *wdd)
  51{
  52        return prcmu_kick_a9wdog(PRCMU_WDOG_ALL);
  53}
  54
  55static int ux500_wdt_set_timeout(struct watchdog_device *wdd,
  56                                 unsigned int timeout)
  57{
  58        ux500_wdt_stop(wdd);
  59        prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
  60        ux500_wdt_start(wdd);
  61
  62        return 0;
  63}
  64
  65static const struct watchdog_info ux500_wdt_info = {
  66        .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
  67        .identity = "Ux500 WDT",
  68        .firmware_version = 1,
  69};
  70
  71static const struct watchdog_ops ux500_wdt_ops = {
  72        .owner = THIS_MODULE,
  73        .start = ux500_wdt_start,
  74        .stop  = ux500_wdt_stop,
  75        .ping  = ux500_wdt_keepalive,
  76        .set_timeout = ux500_wdt_set_timeout,
  77};
  78
  79static struct watchdog_device ux500_wdt = {
  80        .info = &ux500_wdt_info,
  81        .ops = &ux500_wdt_ops,
  82        .min_timeout = WATCHDOG_MIN,
  83        .max_timeout = WATCHDOG_MAX32,
  84};
  85
  86static int ux500_wdt_probe(struct platform_device *pdev)
  87{
  88        struct device *dev = &pdev->dev;
  89        int ret;
  90        struct ux500_wdt_data *pdata = dev_get_platdata(dev);
  91
  92        if (pdata) {
  93                if (pdata->timeout > 0)
  94                        timeout = pdata->timeout;
  95                if (pdata->has_28_bits_resolution)
  96                        ux500_wdt.max_timeout = WATCHDOG_MAX28;
  97        }
  98
  99        ux500_wdt.parent = dev;
 100        watchdog_set_nowayout(&ux500_wdt, nowayout);
 101
 102        /* disable auto off on sleep */
 103        prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
 104
 105        /* set HW initial value */
 106        prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 107
 108        ret = devm_watchdog_register_device(dev, &ux500_wdt);
 109        if (ret)
 110                return ret;
 111
 112        dev_info(dev, "initialized\n");
 113
 114        return 0;
 115}
 116
 117#ifdef CONFIG_PM
 118static int ux500_wdt_suspend(struct platform_device *pdev,
 119                             pm_message_t state)
 120{
 121        if (watchdog_active(&ux500_wdt)) {
 122                ux500_wdt_stop(&ux500_wdt);
 123                prcmu_config_a9wdog(PRCMU_WDOG_CPU1, true);
 124
 125                prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 126                ux500_wdt_start(&ux500_wdt);
 127        }
 128        return 0;
 129}
 130
 131static int ux500_wdt_resume(struct platform_device *pdev)
 132{
 133        if (watchdog_active(&ux500_wdt)) {
 134                ux500_wdt_stop(&ux500_wdt);
 135                prcmu_config_a9wdog(PRCMU_WDOG_CPU1, false);
 136
 137                prcmu_load_a9wdog(PRCMU_WDOG_ALL, timeout * 1000);
 138                ux500_wdt_start(&ux500_wdt);
 139        }
 140        return 0;
 141}
 142#else
 143#define ux500_wdt_suspend NULL
 144#define ux500_wdt_resume NULL
 145#endif
 146
 147static struct platform_driver ux500_wdt_driver = {
 148        .probe          = ux500_wdt_probe,
 149        .suspend        = ux500_wdt_suspend,
 150        .resume         = ux500_wdt_resume,
 151        .driver         = {
 152                .name   = "ux500_wdt",
 153        },
 154};
 155
 156module_platform_driver(ux500_wdt_driver);
 157
 158MODULE_AUTHOR("Jonas Aaberg <jonas.aberg@stericsson.com>");
 159MODULE_DESCRIPTION("Ux500 Watchdog Driver");
 160MODULE_LICENSE("GPL");
 161MODULE_ALIAS("platform:ux500_wdt");
 162