1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * System monitoring driver for DA9052 PMICs. 4 * 5 * Copyright(c) 2012 Dialog Semiconductor Ltd. 6 * 7 * Author: Anthony Olech <Anthony.Olech@diasemi.com> 8 * 9 */ 10 11 #include <linux/module.h> 12 #include <linux/delay.h> 13 #include <linux/uaccess.h> 14 #include <linux/platform_device.h> 15 #include <linux/time.h> 16 #include <linux/watchdog.h> 17 #include <linux/types.h> 18 #include <linux/kernel.h> 19 #include <linux/jiffies.h> 20 21 #include <linux/mfd/da9052/reg.h> 22 #include <linux/mfd/da9052/da9052.h> 23 24 #define DA9052_DEF_TIMEOUT 4 25 #define DA9052_TWDMIN 256 26 27 struct da9052_wdt_data { 28 struct watchdog_device wdt; 29 struct da9052 *da9052; 30 unsigned long jpast; 31 }; 32 33 static const struct { 34 u8 reg_val; 35 int time; /* Seconds */ 36 } da9052_wdt_maps[] = { 37 { 1, 2 }, 38 { 2, 4 }, 39 { 3, 8 }, 40 { 4, 16 }, 41 { 5, 32 }, 42 { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */ 43 { 6, 65 }, 44 { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */ 45 { 7, 131 }, 46 }; 47 48 49 static int da9052_wdt_set_timeout(struct watchdog_device *wdt_dev, 50 unsigned int timeout) 51 { 52 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); 53 struct da9052 *da9052 = driver_data->da9052; 54 int ret, i; 55 56 /* 57 * Disable the Watchdog timer before setting 58 * new time out. 59 */ 60 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, 61 DA9052_CONTROLD_TWDSCALE, 0); 62 if (ret < 0) { 63 dev_err(da9052->dev, "Failed to disable watchdog bit, %d\n", 64 ret); 65 return ret; 66 } 67 if (timeout) { 68 /* 69 * To change the timeout, da9052 needs to 70 * be disabled for at least 150 us. 71 */ 72 udelay(150); 73 74 /* Set the desired timeout */ 75 for (i = 0; i < ARRAY_SIZE(da9052_wdt_maps); i++) 76 if (da9052_wdt_maps[i].time == timeout) 77 break; 78 79 if (i == ARRAY_SIZE(da9052_wdt_maps)) 80 ret = -EINVAL; 81 else 82 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, 83 DA9052_CONTROLD_TWDSCALE, 84 da9052_wdt_maps[i].reg_val); 85 if (ret < 0) { 86 dev_err(da9052->dev, 87 "Failed to update timescale bit, %d\n", ret); 88 return ret; 89 } 90 91 wdt_dev->timeout = timeout; 92 driver_data->jpast = jiffies; 93 } 94 95 return 0; 96 } 97 98 static int da9052_wdt_start(struct watchdog_device *wdt_dev) 99 { 100 return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout); 101 } 102 103 static int da9052_wdt_stop(struct watchdog_device *wdt_dev) 104 { 105 return da9052_wdt_set_timeout(wdt_dev, 0); 106 } 107 108 static int da9052_wdt_ping(struct watchdog_device *wdt_dev) 109 { 110 struct da9052_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev); 111 struct da9052 *da9052 = driver_data->da9052; 112 unsigned long msec, jnow = jiffies; 113 int ret; 114 115 /* 116 * We have a minimum time for watchdog window called TWDMIN. A write 117 * to the watchdog before this elapsed time should cause an error. 118 */ 119 msec = (jnow - driver_data->jpast) * 1000/HZ; 120 if (msec < DA9052_TWDMIN) 121 mdelay(msec); 122 123 /* Reset the watchdog timer */ 124 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, 125 DA9052_CONTROLD_WATCHDOG, 1 << 7); 126 if (ret < 0) 127 return ret; 128 129 /* 130 * FIXME: Reset the watchdog core, in general PMIC 131 * is supposed to do this 132 */ 133 return da9052_reg_update(da9052, DA9052_CONTROL_D_REG, 134 DA9052_CONTROLD_WATCHDOG, 0 << 7); 135 } 136 137 static const struct watchdog_info da9052_wdt_info = { 138 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, 139 .identity = "DA9052 Watchdog", 140 }; 141 142 static const struct watchdog_ops da9052_wdt_ops = { 143 .owner = THIS_MODULE, 144 .start = da9052_wdt_start, 145 .stop = da9052_wdt_stop, 146 .ping = da9052_wdt_ping, 147 .set_timeout = da9052_wdt_set_timeout, 148 }; 149 150 151 static int da9052_wdt_probe(struct platform_device *pdev) 152 { 153 struct device *dev = &pdev->dev; 154 struct da9052 *da9052 = dev_get_drvdata(dev->parent); 155 struct da9052_wdt_data *driver_data; 156 struct watchdog_device *da9052_wdt; 157 int ret; 158 159 driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL); 160 if (!driver_data) 161 return -ENOMEM; 162 driver_data->da9052 = da9052; 163 164 da9052_wdt = &driver_data->wdt; 165 166 da9052_wdt->timeout = DA9052_DEF_TIMEOUT; 167 da9052_wdt->info = &da9052_wdt_info; 168 da9052_wdt->ops = &da9052_wdt_ops; 169 da9052_wdt->parent = dev; 170 watchdog_set_drvdata(da9052_wdt, driver_data); 171 172 ret = da9052_reg_update(da9052, DA9052_CONTROL_D_REG, 173 DA9052_CONTROLD_TWDSCALE, 0); 174 if (ret < 0) { 175 dev_err(dev, "Failed to disable watchdog bits, %d\n", ret); 176 return ret; 177 } 178 179 return devm_watchdog_register_device(dev, &driver_data->wdt); 180 } 181 182 static struct platform_driver da9052_wdt_driver = { 183 .probe = da9052_wdt_probe, 184 .driver = { 185 .name = "da9052-watchdog", 186 }, 187 }; 188 189 module_platform_driver(da9052_wdt_driver); 190 191 MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>"); 192 MODULE_DESCRIPTION("DA9052 SM Device Driver"); 193 MODULE_LICENSE("GPL"); 194 MODULE_ALIAS("platform:da9052-watchdog"); 195