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/i2c.h>
  15 #include <linux/delay.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/mfd/da9062/registers.h>
  18 #include <linux/mfd/da9062/core.h>
  19 #include <linux/regmap.h>
  20 #include <linux/of.h>
  21
  22 static const unsigned int wdt_timeout[] = { 0, 2, 4, 8, 16, 32, 65, 131 };
  23 #define DA9062_TWDSCALE_DISABLE         0
  24 #define DA9062_TWDSCALE_MIN             1
  25 #define DA9062_TWDSCALE_MAX             (ARRAY_SIZE(wdt_timeout) - 1)
  26 #define DA9062_WDT_MIN_TIMEOUT          wdt_timeout[DA9062_TWDSCALE_MIN]
  27 #define DA9062_WDT_MAX_TIMEOUT          wdt_timeout[DA9062_TWDSCALE_MAX]
  28 #define DA9062_WDG_DEFAULT_TIMEOUT      wdt_timeout[DA9062_TWDSCALE_MAX-1]
  29 #define DA9062_RESET_PROTECTION_MS      300
  30
  31 struct da9062_watchdog {
  32         struct da9062 *hw;
  33         struct watchdog_device wdtdev;
  34 };
  35
  36 static unsigned int da9062_wdt_timeout_to_sel(unsigned int secs)
  37 {
  38         unsigned int i;
  39
  40         for (i = DA9062_TWDSCALE_MIN; i <= DA9062_TWDSCALE_MAX; i++) {
  41                 if (wdt_timeout[i] >= secs)
  42                         return i;
  43         }
  44
  45         return DA9062_TWDSCALE_MAX;
  46 }
  47
  48 static int da9062_reset_watchdog_timer(struct da9062_watchdog *wdt)
  49 {
  50         return regmap_update_bits(wdt->hw->regmap, DA9062AA_CONTROL_F,
  51                                   DA9062AA_WATCHDOG_MASK,
  52                                   DA9062AA_WATCHDOG_MASK);
  53 }
  54
  55 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt,
  56                                               unsigned int regval)
  57 {
  58         struct da9062 *chip = wdt->hw;
  59         int ret;
  60
  61         ret = da9062_reset_watchdog_timer(wdt);
  62         if (ret)
  63                 return ret;
  64
  65         regmap_update_bits(chip->regmap,
  66                                   DA9062AA_CONTROL_D,
  67                                   DA9062AA_TWDSCALE_MASK,
  68                                   DA9062_TWDSCALE_DISABLE);
  69
  70         usleep_range(150, 300);
  71
  72         return regmap_update_bits(chip->regmap,
  73                                   DA9062AA_CONTROL_D,
  74                                   DA9062AA_TWDSCALE_MASK,
  75                                   regval);
  76 }
  77
  78 static int da9062_wdt_start(struct watchdog_device *wdd)
  79 {
  80         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
  81         unsigned int selector;
  82         int ret;
  83
  84         selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout);
  85         ret = da9062_wdt_update_timeout_register(wdt, selector);
  86         if (ret)
  87                 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n",
  88                         ret);
  89
  90         return ret;
  91 }
  92
  93 static int da9062_wdt_stop(struct watchdog_device *wdd)
  94 {
  95         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
  96         int ret;
  97
  98         ret = da9062_reset_watchdog_timer(wdt);
  99         if (ret) {
 100                 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
 101                         ret);
 102                 return ret;
 103         }
 104
 105         ret = regmap_update_bits(wdt->hw->regmap,
 106                                  DA9062AA_CONTROL_D,
 107                                  DA9062AA_TWDSCALE_MASK,
 108                                  DA9062_TWDSCALE_DISABLE);
 109         if (ret)
 110                 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n",
 111                         ret);
 112
 113         return ret;
 114 }
 115
 116 static int da9062_wdt_ping(struct watchdog_device *wdd)
 117 {
 118         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 119         int ret;
 120
 121         ret = da9062_reset_watchdog_timer(wdt);
 122         if (ret)
 123                 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n",
 124                         ret);
 125
 126         return ret;
 127 }
 128
 129 static int da9062_wdt_set_timeout(struct watchdog_device *wdd,
 130                                   unsigned int timeout)
 131 {
 132         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 133         unsigned int selector;
 134         int ret;
 135
 136         selector = da9062_wdt_timeout_to_sel(timeout);
 137         ret = da9062_wdt_update_timeout_register(wdt, selector);
 138         if (ret)
 139                 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n",
 140                         ret);
 141         else
 142                 wdd->timeout = wdt_timeout[selector];
 143
 144         return ret;
 145 }
 146
 147 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action,
 148                               void *data)
 149 {
 150         struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd);
 151         struct i2c_client *client = to_i2c_client(wdt->hw->dev);
 152         int ret;
 153
 154         /* Don't use regmap because it is not atomic safe */
 155         ret = i2c_smbus_write_byte_data(client, DA9062AA_CONTROL_F,
 156                                         DA9062AA_SHUTDOWN_MASK);
 157         if (ret < 0)
 158                 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n",
 159                           ret);
 160
 161         /* wait for reset to assert... */
 162         mdelay(500);
 163
 164         return ret;
 165 }
 166
 167 static const struct watchdog_info da9062_watchdog_info = {
 168         .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
 169         .identity = "DA9062 WDT",
 170 };
 171
 172 static const struct watchdog_ops da9062_watchdog_ops = {
 173         .owner = THIS_MODULE,
 174         .start = da9062_wdt_start,
 175         .stop = da9062_wdt_stop,
 176         .ping = da9062_wdt_ping,
 177         .set_timeout = da9062_wdt_set_timeout,
 178         .restart = da9062_wdt_restart,
 179 };
 180
 181 static const struct of_device_id da9062_compatible_id_table[] = {
 182         { .compatible = "dlg,da9062-watchdog", },
 183         { },
 184 };
 185
 186 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table);
 187
 188 static int da9062_wdt_probe(struct platform_device *pdev)
 189 {
 190         struct device *dev = &pdev->dev;
 191         int ret;
 192         struct da9062 *chip;
 193         struct da9062_watchdog *wdt;
 194
 195         chip = dev_get_drvdata(dev->parent);
 196         if (!chip)
 197                 return -EINVAL;
 198
 199         wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
 200         if (!wdt)
 201                 return -ENOMEM;
 202
 203         wdt->hw = chip;
 204
 205         wdt->wdtdev.info = &da9062_watchdog_info;
 206         wdt->wdtdev.ops = &da9062_watchdog_ops;
 207         wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT;
 208         wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT;
 209         wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS;
 210         wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT;
 211         wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS;
 212         wdt->wdtdev.parent = dev;
 213
 214         watchdog_set_restart_priority(&wdt->wdtdev, 128);
 215
 216         watchdog_set_drvdata(&wdt->wdtdev, wdt);
 217         dev_set_drvdata(dev, &wdt->wdtdev);
 218
 219         ret = devm_watchdog_register_device(dev, &wdt->wdtdev);
 220         if (ret < 0)
 221                 return ret;
 222
 223         return da9062_wdt_ping(&wdt->wdtdev);
 224 }
 225
 226 static int __maybe_unused da9062_wdt_suspend(struct device *dev)
 227 {
 228         struct watchdog_device *wdd = dev_get_drvdata(dev);
 229
 230         if (watchdog_active(wdd))
 231                 return da9062_wdt_stop(wdd);
 232
 233         return 0;
 234 }
 235
 236 static int __maybe_unused da9062_wdt_resume(struct device *dev)
 237 {
 238         struct watchdog_device *wdd = dev_get_drvdata(dev);
 239
 240         if (watchdog_active(wdd))
 241                 return da9062_wdt_start(wdd);
 242
 243         return 0;
 244 }
 245
 246 static SIMPLE_DEV_PM_OPS(da9062_wdt_pm_ops,
 247                          da9062_wdt_suspend, da9062_wdt_resume);
 248
 249 static struct platform_driver da9062_wdt_driver = {
 250         .probe = da9062_wdt_probe,
 251         .driver = {
 252                 .name = "da9062-watchdog",
 253                 .pm = &da9062_wdt_pm_ops,
 254                 .of_match_table = da9062_compatible_id_table,
 255         },
 256 };
 257 module_platform_driver(da9062_wdt_driver);
 258
 259 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 260 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061");
 261 MODULE_LICENSE("GPL");
 262 MODULE_ALIAS("platform:da9062-watchdog");