Laxman Dewangan | ff3bb2f | 2016-06-09 18:59:05 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Maxim MAX77620 Watchdog Driver |
| 3 | * |
| 4 | * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved. |
| 5 | * |
| 6 | * Author: Laxman Dewangan <ldewangan@nvidia.com> |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/err.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/mfd/max77620.h> |
| 18 | #include <linux/platform_device.h> |
| 19 | #include <linux/regmap.h> |
| 20 | #include <linux/slab.h> |
| 21 | #include <linux/watchdog.h> |
| 22 | |
| 23 | static bool nowayout = WATCHDOG_NOWAYOUT; |
| 24 | |
| 25 | struct max77620_wdt { |
| 26 | struct device *dev; |
| 27 | struct regmap *rmap; |
| 28 | struct watchdog_device wdt_dev; |
| 29 | }; |
| 30 | |
| 31 | static int max77620_wdt_start(struct watchdog_device *wdt_dev) |
| 32 | { |
| 33 | struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); |
| 34 | |
| 35 | return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, |
| 36 | MAX77620_WDTEN, MAX77620_WDTEN); |
| 37 | } |
| 38 | |
| 39 | static int max77620_wdt_stop(struct watchdog_device *wdt_dev) |
| 40 | { |
| 41 | struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); |
| 42 | |
| 43 | return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, |
| 44 | MAX77620_WDTEN, 0); |
| 45 | } |
| 46 | |
| 47 | static int max77620_wdt_ping(struct watchdog_device *wdt_dev) |
| 48 | { |
| 49 | struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); |
| 50 | |
| 51 | return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, |
| 52 | MAX77620_WDTC_MASK, 0x1); |
| 53 | } |
| 54 | |
| 55 | static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev, |
| 56 | unsigned int timeout) |
| 57 | { |
| 58 | struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); |
| 59 | unsigned int wdt_timeout; |
| 60 | u8 regval; |
| 61 | int ret; |
| 62 | |
| 63 | switch (timeout) { |
| 64 | case 0 ... 2: |
| 65 | regval = MAX77620_TWD_2s; |
| 66 | wdt_timeout = 2; |
| 67 | break; |
| 68 | |
| 69 | case 3 ... 16: |
| 70 | regval = MAX77620_TWD_16s; |
| 71 | wdt_timeout = 16; |
| 72 | break; |
| 73 | |
| 74 | case 17 ... 64: |
| 75 | regval = MAX77620_TWD_64s; |
| 76 | wdt_timeout = 64; |
| 77 | break; |
| 78 | |
| 79 | default: |
| 80 | regval = MAX77620_TWD_128s; |
| 81 | wdt_timeout = 128; |
| 82 | break; |
| 83 | } |
| 84 | |
| 85 | ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, |
| 86 | MAX77620_WDTC_MASK, 0x1); |
| 87 | if (ret < 0) |
| 88 | return ret; |
| 89 | |
| 90 | ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, |
| 91 | MAX77620_TWD_MASK, regval); |
| 92 | if (ret < 0) |
| 93 | return ret; |
| 94 | |
| 95 | wdt_dev->timeout = wdt_timeout; |
| 96 | |
| 97 | return 0; |
| 98 | } |
| 99 | |
| 100 | static const struct watchdog_info max77620_wdt_info = { |
| 101 | .identity = "max77620-watchdog", |
| 102 | .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, |
| 103 | }; |
| 104 | |
| 105 | static const struct watchdog_ops max77620_wdt_ops = { |
| 106 | .start = max77620_wdt_start, |
| 107 | .stop = max77620_wdt_stop, |
| 108 | .ping = max77620_wdt_ping, |
| 109 | .set_timeout = max77620_wdt_set_timeout, |
| 110 | }; |
| 111 | |
| 112 | static int max77620_wdt_probe(struct platform_device *pdev) |
| 113 | { |
| 114 | struct max77620_wdt *wdt; |
| 115 | struct watchdog_device *wdt_dev; |
| 116 | unsigned int regval; |
| 117 | int ret; |
| 118 | |
| 119 | wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); |
| 120 | if (!wdt) |
| 121 | return -ENOMEM; |
| 122 | |
| 123 | wdt->dev = &pdev->dev; |
| 124 | wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL); |
| 125 | if (!wdt->rmap) { |
| 126 | dev_err(wdt->dev, "Failed to get parent regmap\n"); |
| 127 | return -ENODEV; |
| 128 | } |
| 129 | |
| 130 | wdt_dev = &wdt->wdt_dev; |
| 131 | wdt_dev->info = &max77620_wdt_info; |
| 132 | wdt_dev->ops = &max77620_wdt_ops; |
| 133 | wdt_dev->min_timeout = 2; |
| 134 | wdt_dev->max_timeout = 128; |
| 135 | wdt_dev->max_hw_heartbeat_ms = 128 * 1000; |
| 136 | |
| 137 | platform_set_drvdata(pdev, wdt); |
| 138 | |
| 139 | /* Enable WD_RST_WK - WDT expire results in a restart */ |
| 140 | ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2, |
| 141 | MAX77620_ONOFFCNFG2_WD_RST_WK, |
| 142 | MAX77620_ONOFFCNFG2_WD_RST_WK); |
| 143 | if (ret < 0) { |
| 144 | dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret); |
| 145 | return ret; |
| 146 | } |
| 147 | |
| 148 | /* Set WDT clear in OFF and sleep mode */ |
| 149 | ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, |
| 150 | MAX77620_WDTOFFC | MAX77620_WDTSLPC, |
| 151 | MAX77620_WDTOFFC | MAX77620_WDTSLPC); |
| 152 | if (ret < 0) { |
| 153 | dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret); |
| 154 | return ret; |
| 155 | } |
| 156 | |
| 157 | /* Check if WDT running and if yes then set flags properly */ |
| 158 | ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, ®val); |
| 159 | if (ret < 0) { |
| 160 | dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret); |
| 161 | return ret; |
| 162 | } |
| 163 | |
| 164 | switch (regval & MAX77620_TWD_MASK) { |
| 165 | case MAX77620_TWD_2s: |
| 166 | wdt_dev->timeout = 2; |
| 167 | break; |
| 168 | case MAX77620_TWD_16s: |
| 169 | wdt_dev->timeout = 16; |
| 170 | break; |
| 171 | case MAX77620_TWD_64s: |
| 172 | wdt_dev->timeout = 64; |
| 173 | break; |
| 174 | default: |
| 175 | wdt_dev->timeout = 128; |
| 176 | break; |
| 177 | } |
| 178 | |
| 179 | if (regval & MAX77620_WDTEN) |
| 180 | set_bit(WDOG_HW_RUNNING, &wdt_dev->status); |
| 181 | |
| 182 | watchdog_set_nowayout(wdt_dev, nowayout); |
| 183 | watchdog_set_drvdata(wdt_dev, wdt); |
| 184 | |
| 185 | ret = watchdog_register_device(wdt_dev); |
| 186 | if (ret < 0) { |
| 187 | dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret); |
| 188 | return ret; |
| 189 | } |
| 190 | |
| 191 | return 0; |
| 192 | } |
| 193 | |
| 194 | static int max77620_wdt_remove(struct platform_device *pdev) |
| 195 | { |
| 196 | struct max77620_wdt *wdt = platform_get_drvdata(pdev); |
| 197 | |
| 198 | max77620_wdt_stop(&wdt->wdt_dev); |
| 199 | watchdog_unregister_device(&wdt->wdt_dev); |
| 200 | |
| 201 | return 0; |
| 202 | } |
| 203 | |
| 204 | static struct platform_device_id max77620_wdt_devtype[] = { |
| 205 | { .name = "max77620-watchdog", }, |
| 206 | { }, |
| 207 | }; |
Javier Martinez Canillas | f99524d | 2016-10-14 12:23:51 -0300 | [diff] [blame] | 208 | MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype); |
Laxman Dewangan | ff3bb2f | 2016-06-09 18:59:05 +0530 | [diff] [blame] | 209 | |
| 210 | static struct platform_driver max77620_wdt_driver = { |
| 211 | .driver = { |
| 212 | .name = "max77620-watchdog", |
| 213 | }, |
| 214 | .probe = max77620_wdt_probe, |
| 215 | .remove = max77620_wdt_remove, |
| 216 | .id_table = max77620_wdt_devtype, |
| 217 | }; |
| 218 | |
| 219 | module_platform_driver(max77620_wdt_driver); |
| 220 | |
| 221 | MODULE_DESCRIPTION("Max77620 watchdog timer driver"); |
| 222 | |
| 223 | module_param(nowayout, bool, 0); |
| 224 | MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " |
| 225 | "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); |
| 226 | |
| 227 | MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>"); |
| 228 | MODULE_LICENSE("GPL v2"); |