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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 425#define DA9052_TWDMIN 25626 27struct da9052_wdt_data {28 struct watchdog_device wdt;29 struct da9052 *da9052;30 unsigned long jpast;31};32 33static 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 49static 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 setting58 * 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 to70 * 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 else82 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 98static int da9052_wdt_start(struct watchdog_device *wdt_dev)99{100 return da9052_wdt_set_timeout(wdt_dev, wdt_dev->timeout);101}102 103static int da9052_wdt_stop(struct watchdog_device *wdt_dev)104{105 return da9052_wdt_set_timeout(wdt_dev, 0);106}107 108static 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 write117 * 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 PMIC131 * is supposed to do this132 */133 return da9052_reg_update(da9052, DA9052_CONTROL_D_REG,134 DA9052_CONTROLD_WATCHDOG, 0 << 7);135}136 137static const struct watchdog_info da9052_wdt_info = {138 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,139 .identity = "DA9052 Watchdog",140};141 142static 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 151static 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 182static struct platform_driver da9052_wdt_driver = {183 .probe = da9052_wdt_probe,184 .driver = {185 .name = "da9052-watchdog",186 },187};188 189module_platform_driver(da9052_wdt_driver);190 191MODULE_AUTHOR("Anthony Olech <Anthony.Olech@diasemi.com>");192MODULE_DESCRIPTION("DA9052 SM Device Driver");193MODULE_LICENSE("GPL");194MODULE_ALIAS("platform:da9052-watchdog");195