170 lines · c
1// SPDX-License-Identifier: GPL-2.0+2/*3 * System monitoring driver for DA9055 PMICs.4 *5 * Copyright(c) 2012 Dialog Semiconductor Ltd.6 *7 * Author: David Dajun Chen <dchen@diasemi.com>8 *9 */10 11#include <linux/module.h>12#include <linux/types.h>13#include <linux/kernel.h>14#include <linux/slab.h>15#include <linux/platform_device.h>16#include <linux/watchdog.h>17#include <linux/delay.h>18 19#include <linux/mfd/da9055/core.h>20#include <linux/mfd/da9055/reg.h>21 22static bool nowayout = WATCHDOG_NOWAYOUT;23module_param(nowayout, bool, 0);24MODULE_PARM_DESC(nowayout,25 "Watchdog cannot be stopped once started (default="26 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");27 28#define DA9055_DEF_TIMEOUT 429#define DA9055_TWDMIN 25630 31struct da9055_wdt_data {32 struct watchdog_device wdt;33 struct da9055 *da9055;34};35 36static const struct {37 u8 reg_val;38 int user_time; /* In seconds */39} da9055_wdt_maps[] = {40 { 0, 0 },41 { 1, 2 },42 { 2, 4 },43 { 3, 8 },44 { 4, 16 },45 { 5, 32 },46 { 5, 33 }, /* Actual time 32.768s so included both 32s and 33s */47 { 6, 65 },48 { 6, 66 }, /* Actual time 65.536s so include both, 65s and 66s */49 { 7, 131 },50};51 52static int da9055_wdt_set_timeout(struct watchdog_device *wdt_dev,53 unsigned int timeout)54{55 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);56 struct da9055 *da9055 = driver_data->da9055;57 int ret, i;58 59 for (i = 0; i < ARRAY_SIZE(da9055_wdt_maps); i++)60 if (da9055_wdt_maps[i].user_time == timeout)61 break;62 63 if (i == ARRAY_SIZE(da9055_wdt_maps))64 ret = -EINVAL;65 else66 ret = da9055_reg_update(da9055, DA9055_REG_CONTROL_B,67 DA9055_TWDSCALE_MASK,68 da9055_wdt_maps[i].reg_val <<69 DA9055_TWDSCALE_SHIFT);70 if (ret < 0) {71 dev_err(da9055->dev,72 "Failed to update timescale bit, %d\n", ret);73 return ret;74 }75 76 wdt_dev->timeout = timeout;77 78 return 0;79}80 81static int da9055_wdt_ping(struct watchdog_device *wdt_dev)82{83 struct da9055_wdt_data *driver_data = watchdog_get_drvdata(wdt_dev);84 struct da9055 *da9055 = driver_data->da9055;85 86 /*87 * We have a minimum time for watchdog window called TWDMIN. A write88 * to the watchdog before this elapsed time will cause an error.89 */90 mdelay(DA9055_TWDMIN);91 92 /* Reset the watchdog timer */93 return da9055_reg_update(da9055, DA9055_REG_CONTROL_E,94 DA9055_WATCHDOG_MASK, 1);95}96 97static int da9055_wdt_start(struct watchdog_device *wdt_dev)98{99 return da9055_wdt_set_timeout(wdt_dev, wdt_dev->timeout);100}101 102static int da9055_wdt_stop(struct watchdog_device *wdt_dev)103{104 return da9055_wdt_set_timeout(wdt_dev, 0);105}106 107static const struct watchdog_info da9055_wdt_info = {108 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,109 .identity = "DA9055 Watchdog",110};111 112static const struct watchdog_ops da9055_wdt_ops = {113 .owner = THIS_MODULE,114 .start = da9055_wdt_start,115 .stop = da9055_wdt_stop,116 .ping = da9055_wdt_ping,117 .set_timeout = da9055_wdt_set_timeout,118};119 120static int da9055_wdt_probe(struct platform_device *pdev)121{122 struct device *dev = &pdev->dev;123 struct da9055 *da9055 = dev_get_drvdata(dev->parent);124 struct da9055_wdt_data *driver_data;125 struct watchdog_device *da9055_wdt;126 int ret;127 128 driver_data = devm_kzalloc(dev, sizeof(*driver_data), GFP_KERNEL);129 if (!driver_data)130 return -ENOMEM;131 132 driver_data->da9055 = da9055;133 134 da9055_wdt = &driver_data->wdt;135 136 da9055_wdt->timeout = DA9055_DEF_TIMEOUT;137 da9055_wdt->info = &da9055_wdt_info;138 da9055_wdt->ops = &da9055_wdt_ops;139 da9055_wdt->parent = dev;140 watchdog_set_nowayout(da9055_wdt, nowayout);141 watchdog_set_drvdata(da9055_wdt, driver_data);142 143 ret = da9055_wdt_stop(da9055_wdt);144 if (ret < 0) {145 dev_err(dev, "Failed to stop watchdog, %d\n", ret);146 return ret;147 }148 149 ret = devm_watchdog_register_device(dev, &driver_data->wdt);150 if (ret != 0)151 dev_err(da9055->dev, "watchdog_register_device() failed: %d\n",152 ret);153 154 return ret;155}156 157static struct platform_driver da9055_wdt_driver = {158 .probe = da9055_wdt_probe,159 .driver = {160 .name = "da9055-watchdog",161 },162};163 164module_platform_driver(da9055_wdt_driver);165 166MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");167MODULE_DESCRIPTION("DA9055 watchdog");168MODULE_LICENSE("GPL");169MODULE_ALIAS("platform:da9055-watchdog");170