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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Watchdog driver for Ricoh RN5T618 PMIC4 *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 16static bool nowayout = WATCHDOG_NOWAYOUT;17static unsigned int timeout;18 19module_param(timeout, uint, 0);20MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds");21 22module_param(nowayout, bool, 0);23MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="24 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");25 26struct 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 supported33 * watchdog expiration times. If the watchdog is not accessed before34 * the timer expiration, the PMU generates an interrupt and if the CPU35 * doesn't clear it within one second the system is restarted.36 */37static 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 47static 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 70static 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 99static 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 107static 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 127static const struct watchdog_info rn5t618_wdt_info = {128 .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE |129 WDIOF_KEEPALIVEPING,130 .identity = DRIVER_NAME,131};132 133static 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 141static 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 184static struct platform_driver rn5t618_wdt_driver = {185 .probe = rn5t618_wdt_probe,186 .driver = {187 .name = DRIVER_NAME,188 },189};190 191module_platform_driver(rn5t618_wdt_driver);192 193MODULE_ALIAS("platform:rn5t618-wdt");194MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");195MODULE_DESCRIPTION("RN5T618 watchdog driver");196MODULE_LICENSE("GPL v2");197