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"); 239