drivers/watchdog/da9062_wdt.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Watchdog device driver for DA9062 and DA9061 PMICs
   4  * Copyright (C) 2015  Dialog Semiconductor Ltd.
   5  *
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/module.h>
  10 #include <linux/watchdog.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/slab.h>
  14 #include <linux/delay.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/mfd/da9062/registers.h>
  17 #include <linux/mfd/da9062/core.h>
  18 #include <linux/regmap.h>
  19 #include <linux/of.h>
  20
  21 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
  22 #define DA9062_TWDSCALE_DISABLE         0
  23 #define DA9062_TWDSCALE_MIN             1
  24 #define DA9062_TWDSCALE_MAX             (ARRAY_SIZE(wdt_timeout) - 1)
  25 #define DA9062_WDT_MIN_TIMEOUT          wdt_timeout[DA9062_TWDSCALE_MIN]
  26 #define DA9062_WDT_MAX_TIMEOUT          wdt_timeout[DA9062_TWDSCALE_MAX]
  27 #define DA9062_WDG_DEFAULT_TIMEOUT      wdt_timeout[DA9062_TWDSCALE_MAX-1]
  28 #define DA9062_RESET_PROTECTION_MS      300
  29
  30 struct da9062_watchdog {
  31         struct da9062 *hw;
  32         struct watchdog_device wdtdev;
  33 };
  34
  35 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
  36 {
  37         unsigned int i;
  38
  39         for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
  40                 if (wdt_timeout[i] >= secs)
  41                         return i;
  42         }
  43
  44         return DA9062_TWDSCALE_MAX;
  45 }
  46
  47 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
  48 {
  49         return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
  50                                   DA9062AA_WATCHDOG_MASK,
  51                                   DA9062AA_WATCHDOG_MASK);
  52 }
  53
  54 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
  55                                               unsigned int regval)
  56 {
  57         struct da9062 *chip = wdt->hw;
  58         int ret;
  59
  60         ret = da9062_reset_watchdog_timer(wdt);
  61         if (ret)
  62                 return ret;
  63
  64         regmap_update_bits(chip->regmap,
  65                                   DA9062AA_CONTROL_D,
  66                                   DA9062AA_TWDSCALE_MASK,
  67                                   DA9062_TWDSCALE_DISABLE);
  68
  69         usleep_range(150, 300);
  70
  71         return regmap_update_bits(chip->regmap,
  72                                   DA9062AA_CONTROL_D,
  73                                   DA9062AA_TWDSCALE_MASK,
  74                                   regval);
  75 }
  76
  77 static int da9062_wdt_start(struct watchdog_device *wdd)
  78 {
  79         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
  80         unsigned int selector;
  81         int ret;
  82
  83         selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
  84         ret = da9062_wdt_update_timeout_register(wdt, selector);
  85         if (ret)
  86                 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
  87                         ret);
  88
  89         return ret;
  90 }
  91
  92 static int da9062_wdt_stop(struct watchdog_device *wdd)
  93 {
  94         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
  95         int ret;
  96
  97         ret = da9062_reset_watchdog_timer(wdt);
  98         if (ret) {
  99                 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
 100                         ret);
 101                 return ret;
 102         }
 103
 104         ret = regmap_update_bits(wdt->hw->regmap,
 105                                  DA9062AA_CONTROL_D,
 106                                  DA9062AA_TWDSCALE_MASK,
 107                                  DA9062_TWDSCALE_DISABLE);
 108         if (ret)
 109                 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
 110                         ret);
 111
 112         return ret;
 113 }
 114
 115 static int da9062_wdt_ping(struct watchdog_device *wdd)
 116 {
 117         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 118         int ret;
 119
 120         ret = da9062_reset_watchdog_timer(wdt);
 121         if (ret)
 122                 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
 123                         ret);
 124
 125         return ret;
 126 }
 127
 128 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
 129                                   unsigned int timeout)
 130 {
 131         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 132         unsigned int selector;
 133         int ret;
 134
 135         selector = da9062_wdt_timeout_to_sel(timeout);
 136         ret = da9062_wdt_update_timeout_register(wdt, selector);
 137         if (ret)
 138                 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
 139                         ret);
 140         else
 141                 wdd->timeout = wdt_timeout[selector];
 142
 143         return ret;
 144 }
 145
 146 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 147                               void *data)
 148 {
 149         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 150         int ret;
 151
 152         ret = regmap_write(wdt->hw->regmap,
 153                            DA9062AA_CONTROL_F,
 154                            DA9062AA_SHUTDOWN_MASK);
 155         if (ret)
 156                 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
 157                           ret);
 158
 159         /* wait for reset to assert... */
 160         mdelay(500);
 161
 162         return ret;
 163 }
 164
 165 static const struct watchdog_info da9062_watchdog_info = {
 166         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
 167         .identity = "DA9062 WDT",
 168 };
 169
 170 static const struct watchdog_ops da9062_watchdog_ops = {
 171         .owner = THIS_MODULE,
 172         .start = da9062_wdt_start,
 173         .stop = da9062_wdt_stop,
 174         .ping = da9062_wdt_ping,
 175         .set_timeout = da9062_wdt_set_timeout,
 176         .restart = da9062_wdt_restart,
 177 };
 178
 179 static const struct of_device_id da9062_compatible_id_table[] = {
 180         { .compatible = "dlg,da9062-watchdog", },
 181         { },
 182 };
 183
 184 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
 185
 186 static int da9062_wdt_probe(struct platform_device *pdev)
 187 {
 188         struct device *dev = &pdev->dev;
 189         int ret;
 190         struct da9062 *chip;
 191         struct da9062_watchdog *wdt;
 192
 193         chip = dev_get_drvdata(dev->parent);
 194         if (!chip)
 195                 return -EINVAL;
 196
 197         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 198         if (!wdt)
 199                 return -ENOMEM;
 200
 201         wdt->hw = chip;
 202
 203         wdt->wdtdev.info = &da9062_watchdog_info;
 204         wdt->wdtdev.ops = &da9062_watchdog_ops;
 205         wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
 206         wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
 207         wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
 208         wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
 209         wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 210         wdt->wdtdev.parent = dev;
 211
 212         watchdog_set_restart_priority(&wdt->wdtdev, 128);
 213
 214         watchdog_set_drvdata(&wdt->wdtdev, wdt);
 215
 216         ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
 217         if (ret < 0) {
 218                 dev_err(wdt->hw->dev,
 219                         "watchdog registration failed (%d)\n", ret);
 220                 return ret;
 221         }
 222
 223         return da9062_wdt_ping(&wdt->wdtdev);
 224 }
 225
 226 static struct platform_driver da9062_wdt_driver = {
 227         .probe = da9062_wdt_probe,
 228         .driver = {
 229                 .name = "da9062-watchdog",
 230                 .of_match_table = da9062_compatible_id_table,
 231         },
 232 };
 233 module_platform_driver(da9062_wdt_driver);
 234
 235 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 236 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
 237 MODULE_LICENSE("GPL");
 238 MODULE_ALIAS("platform:da9062-watchdog");