1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Watchdog driver for Ricoh RN5T618 PMIC 4 * 5 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com> 6 */ 7 8 #include <linux/device.h> 9 #include <linux/mfd/rn5t618.h> 10 #include <linux/module.h> 11 #include <linux/platform_device.h> 12 #include <linux/watchdog.h> 13 14 #define DRIVER_NAME "rn5t618-wdt" 15 16 static bool nowayout = WATCHDOG_NOWAYOUT; 17 static unsigned int timeout; 18 19 module_param(timeout, uint, 0); 20 MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); 21 22 module_param(nowayout, bool, 0); 23 MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" 24 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); 25 26 struct rn5t618_wdt { 27 struct watchdog_device wdt_dev; 28 struct rn5t618 *rn5t618; 29 }; 30 31 /* 32 * This array encodes the values of WDOGTIM field for the supported 33 * watchdog expiration times. If the watchdog is not accessed before 34 * the timer expiration, the PMU generates an interrupt and if the CPU 35 * doesn't clear it within one second the system is restarted. 36 */ 37 static const struct { 38 u8 reg_val; 39 unsigned int time; 40 } rn5t618_wdt_map[] = { 41 { 0, 1 }, 42 { 1, 8 }, 43 { 2, 32 }, 44 { 3, 128 }, 45 }; 46 47 static int rn5t618_wdt_set_timeout(struct watchdog_device *wdt_dev, 48 unsigned int t) 49 { 50 struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); 51 int ret, i; 52 53 for (i = 0; i < ARRAY_SIZE(rn5t618_wdt_map); i++) { 54 if (rn5t618_wdt_map[i].time + 1 >= t) 55 break; 56 } 57 58 if (i == ARRAY_SIZE(rn5t618_wdt_map)) 59 return -EINVAL; 60 61 ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, 62 RN5T618_WATCHDOG_WDOGTIM_M, 63 rn5t618_wdt_map[i].reg_val); 64 if (!ret) 65 wdt_dev->timeout = rn5t618_wdt_map[i].time; 66 67 return ret; 68 } 69 70 static int rn5t618_wdt_start(struct watchdog_device *wdt_dev) 71 { 72 struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); 73 int ret; 74 75 ret = rn5t618_wdt_set_timeout(wdt_dev, wdt_dev->timeout); 76 if (ret) 77 return ret; 78 79 /* enable repower-on */ 80 ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_REPCNT, 81 RN5T618_REPCNT_REPWRON, 82 RN5T618_REPCNT_REPWRON); 83 if (ret) 84 return ret; 85 86 /* enable watchdog */ 87 ret = regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, 88 RN5T618_WATCHDOG_WDOGEN, 89 RN5T618_WATCHDOG_WDOGEN); 90 if (ret) 91 return ret; 92 93 /* enable watchdog interrupt */ 94 return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIREN, 95 RN5T618_PWRIRQ_IR_WDOG, 96 RN5T618_PWRIRQ_IR_WDOG); 97 } 98 99 static int rn5t618_wdt_stop(struct watchdog_device *wdt_dev) 100 { 101 struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); 102 103 return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_WATCHDOG, 104 RN5T618_WATCHDOG_WDOGEN, 0); 105 } 106 107 static int rn5t618_wdt_ping(struct watchdog_device *wdt_dev) 108 { 109 struct rn5t618_wdt *wdt = watchdog_get_drvdata(wdt_dev); 110 unsigned int val; 111 int ret; 112 113 /* The counter is restarted after a R/W access to watchdog register */ 114 ret = regmap_read(wdt->rn5t618->regmap, RN5T618_WATCHDOG, &val); 115 if (ret) 116 return ret; 117 118 ret = regmap_write(wdt->rn5t618->regmap, RN5T618_WATCHDOG, val); 119 if (ret) 120 return ret; 121 122 /* Clear pending watchdog interrupt */ 123 return regmap_update_bits(wdt->rn5t618->regmap, RN5T618_PWRIRQ, 124 RN5T618_PWRIRQ_IR_WDOG, 0); 125 } 126 127 static const struct watchdog_info rn5t618_wdt_info = { 128 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | 129 WDIOF_KEEPALIVEPING, 130 .identity = DRIVER_NAME, 131 }; 132 133 static const struct watchdog_ops rn5t618_wdt_ops = { 134 .owner = THIS_MODULE, 135 .start = rn5t618_wdt_start, 136 .stop = rn5t618_wdt_stop, 137 .ping = rn5t618_wdt_ping, 138 .set_timeout = rn5t618_wdt_set_timeout, 139 }; 140 141 static int rn5t618_wdt_probe(struct platform_device *pdev) 142 { 143 struct device *dev = &pdev->dev; 144 struct rn5t618 *rn5t618 = dev_get_drvdata(dev->parent); 145 struct rn5t618_wdt *wdt; 146 int min_timeout, max_timeout; 147 int ret; 148 unsigned int val; 149 150 wdt = devm_kzalloc(dev, sizeof(struct rn5t618_wdt), GFP_KERNEL); 151 if (!wdt) 152 return -ENOMEM; 153 154 min_timeout = rn5t618_wdt_map[0].time; 155 max_timeout = rn5t618_wdt_map[ARRAY_SIZE(rn5t618_wdt_map) - 1].time; 156 157 wdt->rn5t618 = rn5t618; 158 wdt->wdt_dev.info = &rn5t618_wdt_info; 159 wdt->wdt_dev.ops = &rn5t618_wdt_ops; 160 wdt->wdt_dev.min_timeout = min_timeout; 161 wdt->wdt_dev.max_timeout = max_timeout; 162 wdt->wdt_dev.timeout = max_timeout; 163 wdt->wdt_dev.parent = dev; 164 165 /* Read out previous power-off factor */ 166 ret = regmap_read(wdt->rn5t618->regmap, RN5T618_POFFHIS, &val); 167 if (ret) 168 return ret; 169 170 if (val & RN5T618_POFFHIS_VINDET) 171 wdt->wdt_dev.bootstatus = WDIOF_POWERUNDER; 172 else if (val & RN5T618_POFFHIS_WDG) 173 wdt->wdt_dev.bootstatus = WDIOF_CARDRESET; 174 175 watchdog_set_drvdata(&wdt->wdt_dev, wdt); 176 watchdog_init_timeout(&wdt->wdt_dev, timeout, dev); 177 watchdog_set_nowayout(&wdt->wdt_dev, nowayout); 178 179 platform_set_drvdata(pdev, wdt); 180 181 return devm_watchdog_register_device(dev, &wdt->wdt_dev); 182 } 183 184 static struct platform_driver rn5t618_wdt_driver = { 185 .probe = rn5t618_wdt_probe, 186 .driver = { 187 .name = DRIVER_NAME, 188 }, 189 }; 190 191 module_platform_driver(rn5t618_wdt_driver); 192 193 MODULE_ALIAS("platform:rn5t618-wdt"); 194 MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>"); 195 MODULE_DESCRIPTION("RN5T618 watchdog driver"); 196 MODULE_LICENSE("GPL v2"); 197