drivers/watchdog/da9063_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Watchdog driver for DA9063 PMICs.
   4  *
   5  * Copyright(c) 2012 Dialog Semiconductor Ltd.
   6  *
   7  * Author: Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>
   8  *
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/watchdog.h>
  14 #include <linux/platform_device.h>
  15 #include <linux/uaccess.h>
  16 #include <linux/slab.h>
  17 #include <linux/delay.h>
  18 #include <linux/mfd/da9063/registers.h>
  19 #include <linux/mfd/da9063/core.h>
  20 #include <linux/regmap.h>
  21
  22 /*
  23  * Watchdog selector to timeout in seconds.
  24  *   0: WDT disabled;
  25  *   others: timeout = 2048 ms * 2^(TWDSCALE-1).
  26  */
  27 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
  28 #define DA9063_TWDSCALE_DISABLE         0
  29 #define DA9063_TWDSCALE_MIN             1
  30 #define DA9063_TWDSCALE_MAX             (ARRAY_SIZE(wdt_timeout) - 1)
  31 #define DA9063_WDT_MIN_TIMEOUT          wdt_timeout[DA9063_TWDSCALE_MIN]
  32 #define DA9063_WDT_MAX_TIMEOUT          wdt_timeout[DA9063_TWDSCALE_MAX]
  33 #define DA9063_WDG_TIMEOUT              wdt_timeout[3]
  34 #define DA9063_RESET_PROTECTION_MS      256
  35
  36 static unsigned int da9063_wdt_timeout_to_sel(unsigned int secs)
  37 {
  38         unsigned int i;
  39
  40         for (i = DA9063_TWDSCALE_MIN; i <= DA9063_TWDSCALE_MAX; i++) {
  41                 if (wdt_timeout[i] >= secs)
  42                         return i;
  43         }
  44
  45         return DA9063_TWDSCALE_MAX;
  46 }
  47
  48 static int _da9063_wdt_set_timeout(struct da9063 *da9063, unsigned int regval)
  49 {
  50         return regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
  51                                   DA9063_TWDSCALE_MASK, regval);
  52 }
  53
  54 static int da9063_wdt_start(struct watchdog_device *wdd)
  55 {
  56         struct da9063 *da9063 = watchdog_get_drvdata(wdd);
  57         unsigned int selector;
  58         int ret;
  59
  60         selector = da9063_wdt_timeout_to_sel(wdd->timeout);
  61         ret = _da9063_wdt_set_timeout(da9063, selector);
  62         if (ret)
  63                 dev_err(da9063->dev, "Watchdog failed to start (err = %d)\n",
  64                         ret);
  65
  66         return ret;
  67 }
  68
  69 static int da9063_wdt_stop(struct watchdog_device *wdd)
  70 {
  71         struct da9063 *da9063 = watchdog_get_drvdata(wdd);
  72         int ret;
  73
  74         ret = regmap_update_bits(da9063->regmap, DA9063_REG_CONTROL_D,
  75                                  DA9063_TWDSCALE_MASK, DA9063_TWDSCALE_DISABLE);
  76         if (ret)
  77                 dev_alert(da9063->dev, "Watchdog failed to stop (err = %d)\n",
  78                           ret);
  79
  80         return ret;
  81 }
  82
  83 static int da9063_wdt_ping(struct watchdog_device *wdd)
  84 {
  85         struct da9063 *da9063 = watchdog_get_drvdata(wdd);
  86         int ret;
  87
  88         ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
  89                            DA9063_WATCHDOG);
  90         if (ret)
  91                 dev_alert(da9063->dev, "Failed to ping the watchdog (err = %d)\n",
  92                           ret);
  93
  94         return ret;
  95 }
  96
  97 static int da9063_wdt_set_timeout(struct watchdog_device *wdd,
  98                                   unsigned int timeout)
  99 {
 100         struct da9063 *da9063 = watchdog_get_drvdata(wdd);
 101         unsigned int selector;
 102         int ret;
 103
 104         selector = da9063_wdt_timeout_to_sel(timeout);
 105         ret = _da9063_wdt_set_timeout(da9063, selector);
 106         if (ret)
 107                 dev_err(da9063->dev, "Failed to set watchdog timeout (err = %d)\n",
 108                         ret);
 109         else
 110                 wdd->timeout = wdt_timeout[selector];
 111
 112         return ret;
 113 }
 114
 115 static int da9063_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 116                               void *data)
 117 {
 118         struct da9063 *da9063 = watchdog_get_drvdata(wdd);
 119         int ret;
 120
 121         ret = regmap_write(da9063->regmap, DA9063_REG_CONTROL_F,
 122                            DA9063_SHUTDOWN);
 123         if (ret)
 124                 dev_alert(da9063->dev, "Failed to shutdown (err = %d)\n",
 125                           ret);
 126
 127         return ret;
 128 }
 129
 130 static const struct watchdog_info da9063_watchdog_info = {
 131         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
 132         .identity = "DA9063 Watchdog",
 133 };
 134
 135 static const struct watchdog_ops da9063_watchdog_ops = {
 136         .owner = THIS_MODULE,
 137         .start = da9063_wdt_start,
 138         .stop = da9063_wdt_stop,
 139         .ping = da9063_wdt_ping,
 140         .set_timeout = da9063_wdt_set_timeout,
 141         .restart = da9063_wdt_restart,
 142 };
 143
 144 static int da9063_wdt_probe(struct platform_device *pdev)
 145 {
 146         struct da9063 *da9063;
 147         struct watchdog_device *wdd;
 148
 149         if (!pdev->dev.parent)
 150                 return -EINVAL;
 151
 152         da9063 = dev_get_drvdata(pdev->dev.parent);
 153         if (!da9063)
 154                 return -EINVAL;
 155
 156         wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL);
 157         if (!wdd)
 158                 return -ENOMEM;
 159
 160         wdd->info = &da9063_watchdog_info;
 161         wdd->ops = &da9063_watchdog_ops;
 162         wdd->min_timeout = DA9063_WDT_MIN_TIMEOUT;
 163         wdd->max_timeout = DA9063_WDT_MAX_TIMEOUT;
 164         wdd->min_hw_heartbeat_ms = DA9063_RESET_PROTECTION_MS;
 165         wdd->timeout = DA9063_WDG_TIMEOUT;
 166         wdd->parent = &pdev->dev;
 167
 168         wdd->status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 169
 170         watchdog_set_restart_priority(wdd, 128);
 171
 172         watchdog_set_drvdata(wdd, da9063);
 173
 174         return devm_watchdog_register_device(&pdev->dev, wdd);
 175 }
 176
 177 static struct platform_driver da9063_wdt_driver = {
 178         .probe = da9063_wdt_probe,
 179         .driver = {
 180                 .name = DA9063_DRVNAME_WATCHDOG,
 181         },
 182 };
 183 module_platform_driver(da9063_wdt_driver);
 184
 185 MODULE_AUTHOR("Mariusz Wojtasik <mariusz.wojtasik@diasemi.com>");
 186 MODULE_DESCRIPTION("Watchdog driver for Dialog DA9063");
 187 MODULE_LICENSE("GPL");
 188 MODULE_ALIAS("platform:" DA9063_DRVNAME_WATCHDOG);