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 int ret; 50 51 ret = regmap_update_bits(wdt->hw->regmap, 52 DA9062AA_CONTROL_F, 53 DA9062AA_WATCHDOG_MASK, 54 DA9062AA_WATCHDOG_MASK); 55 56 return ret; 57 } 58 59 static int da9062_wdt_update_timeout_register(struct da9062_watchdog *wdt, 60 unsigned int regval) 61 { 62 struct da9062 *chip = wdt->hw; 63 int ret; 64 65 ret = da9062_reset_watchdog_timer(wdt); 66 if (ret) 67 return ret; 68 69 regmap_update_bits(chip->regmap, 70 DA9062AA_CONTROL_D, 71 DA9062AA_TWDSCALE_MASK, 72 DA9062_TWDSCALE_DISABLE); 73 74 usleep_range(150, 300); 75 76 return regmap_update_bits(chip->regmap, 77 DA9062AA_CONTROL_D, 78 DA9062AA_TWDSCALE_MASK, 79 regval); 80 } 81 82 static int da9062_wdt_start(struct watchdog_device *wdd) 83 { 84 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); 85 unsigned int selector; 86 int ret; 87 88 selector = da9062_wdt_timeout_to_sel(wdt->wdtdev.timeout); 89 ret = da9062_wdt_update_timeout_register(wdt, selector); 90 if (ret) 91 dev_err(wdt->hw->dev, "Watchdog failed to start (err = %d)\n", 92 ret); 93 94 return ret; 95 } 96 97 static int da9062_wdt_stop(struct watchdog_device *wdd) 98 { 99 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); 100 int ret; 101 102 ret = da9062_reset_watchdog_timer(wdt); 103 if (ret) { 104 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", 105 ret); 106 return ret; 107 } 108 109 ret = regmap_update_bits(wdt->hw->regmap, 110 DA9062AA_CONTROL_D, 111 DA9062AA_TWDSCALE_MASK, 112 DA9062_TWDSCALE_DISABLE); 113 if (ret) 114 dev_err(wdt->hw->dev, "Watchdog failed to stop (err = %d)\n", 115 ret); 116 117 return ret; 118 } 119 120 static int da9062_wdt_ping(struct watchdog_device *wdd) 121 { 122 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); 123 int ret; 124 125 ret = da9062_reset_watchdog_timer(wdt); 126 if (ret) 127 dev_err(wdt->hw->dev, "Failed to ping the watchdog (err = %d)\n", 128 ret); 129 130 return ret; 131 } 132 133 static int da9062_wdt_set_timeout(struct watchdog_device *wdd, 134 unsigned int timeout) 135 { 136 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); 137 unsigned int selector; 138 int ret; 139 140 selector = da9062_wdt_timeout_to_sel(timeout); 141 ret = da9062_wdt_update_timeout_register(wdt, selector); 142 if (ret) 143 dev_err(wdt->hw->dev, "Failed to set watchdog timeout (err = %d)\n", 144 ret); 145 else 146 wdd->timeout = wdt_timeout[selector]; 147 148 return ret; 149 } 150 151 static int da9062_wdt_restart(struct watchdog_device *wdd, unsigned long action, 152 void *data) 153 { 154 struct da9062_watchdog *wdt = watchdog_get_drvdata(wdd); 155 int ret; 156 157 ret = regmap_write(wdt->hw->regmap, 158 DA9062AA_CONTROL_F, 159 DA9062AA_SHUTDOWN_MASK); 160 if (ret) 161 dev_alert(wdt->hw->dev, "Failed to shutdown (err = %d)\n", 162 ret); 163 164 /* wait for reset to assert... */ 165 mdelay(500); 166 167 return ret; 168 } 169 170 static const struct watchdog_info da9062_watchdog_info = { 171 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 172 .identity = "DA9062 WDT", 173 }; 174 175 static const struct watchdog_ops da9062_watchdog_ops = { 176 .owner = THIS_MODULE, 177 .start = da9062_wdt_start, 178 .stop = da9062_wdt_stop, 179 .ping = da9062_wdt_ping, 180 .set_timeout = da9062_wdt_set_timeout, 181 .restart = da9062_wdt_restart, 182 }; 183 184 static const struct of_device_id da9062_compatible_id_table[] = { 185 { .compatible = "dlg,da9062-watchdog", }, 186 { }, 187 }; 188 189 MODULE_DEVICE_TABLE(of, da9062_compatible_id_table); 190 191 static int da9062_wdt_probe(struct platform_device *pdev) 192 { 193 int ret; 194 struct da9062 *chip; 195 struct da9062_watchdog *wdt; 196 197 chip = dev_get_drvdata(pdev->dev.parent); 198 if (!chip) 199 return -EINVAL; 200 201 wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); 202 if (!wdt) 203 return -ENOMEM; 204 205 wdt->hw = chip; 206 207 wdt->wdtdev.info = &da9062_watchdog_info; 208 wdt->wdtdev.ops = &da9062_watchdog_ops; 209 wdt->wdtdev.min_timeout = DA9062_WDT_MIN_TIMEOUT; 210 wdt->wdtdev.max_timeout = DA9062_WDT_MAX_TIMEOUT; 211 wdt->wdtdev.min_hw_heartbeat_ms = DA9062_RESET_PROTECTION_MS; 212 wdt->wdtdev.timeout = DA9062_WDG_DEFAULT_TIMEOUT; 213 wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS; 214 wdt->wdtdev.parent = &pdev->dev; 215 216 watchdog_set_restart_priority(&wdt->wdtdev, 128); 217 218 watchdog_set_drvdata(&wdt->wdtdev, wdt); 219 220 ret = devm_watchdog_register_device(&pdev->dev, &wdt->wdtdev); 221 if (ret < 0) { 222 dev_err(wdt->hw->dev, 223 "watchdog registration failed (%d)\n", ret); 224 return ret; 225 } 226 227 return da9062_wdt_ping(&wdt->wdtdev); 228 } 229 230 static struct platform_driver da9062_wdt_driver = { 231 .probe = da9062_wdt_probe, 232 .driver = { 233 .name = "da9062-watchdog", 234 .of_match_table = da9062_compatible_id_table, 235 }, 236 }; 237 module_platform_driver(da9062_wdt_driver); 238 239 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>"); 240 MODULE_DESCRIPTION("WDT device driver for Dialog DA9062 and DA9061"); 241 MODULE_LICENSE("GPL"); 242 MODULE_ALIAS("platform:da9062-watchdog"); 243