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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Watchdog driver for Technologic Systems TS-72xx based SBCs4 * (TS-7200, TS-7250 and TS-7260). These boards have external5 * glue logic CPLD chip, which includes programmable watchdog6 * timer.7 *8 * Copyright (c) 2009 Mika Westerberg <mika.westerberg@iki.fi>9 *10 * This driver is based on ep93xx_wdt and wm831x_wdt drivers.11 *12 */13 14#include <linux/platform_device.h>15#include <linux/mod_devicetable.h>16#include <linux/module.h>17#include <linux/watchdog.h>18#include <linux/io.h>19 20#define TS72XX_WDT_DEFAULT_TIMEOUT 3021 22static int timeout;23module_param(timeout, int, 0);24MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds.");25 26static bool nowayout = WATCHDOG_NOWAYOUT;27module_param(nowayout, bool, 0);28MODULE_PARM_DESC(nowayout, "Disable watchdog shutdown on close");29 30/* priv->control_reg */31#define TS72XX_WDT_CTRL_DISABLE 0x0032#define TS72XX_WDT_CTRL_250MS 0x0133#define TS72XX_WDT_CTRL_500MS 0x0234#define TS72XX_WDT_CTRL_1SEC 0x0335#define TS72XX_WDT_CTRL_RESERVED 0x0436#define TS72XX_WDT_CTRL_2SEC 0x0537#define TS72XX_WDT_CTRL_4SEC 0x0638#define TS72XX_WDT_CTRL_8SEC 0x0739 40/* priv->feed_reg */41#define TS72XX_WDT_FEED_VAL 0x0542 43struct ts72xx_wdt_priv {44 void __iomem *control_reg;45 void __iomem *feed_reg;46 struct watchdog_device wdd;47 unsigned char regval;48};49 50static int ts72xx_wdt_start(struct watchdog_device *wdd)51{52 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);53 54 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);55 writeb(priv->regval, priv->control_reg);56 57 return 0;58}59 60static int ts72xx_wdt_stop(struct watchdog_device *wdd)61{62 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);63 64 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);65 writeb(TS72XX_WDT_CTRL_DISABLE, priv->control_reg);66 67 return 0;68}69 70static int ts72xx_wdt_ping(struct watchdog_device *wdd)71{72 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);73 74 writeb(TS72XX_WDT_FEED_VAL, priv->feed_reg);75 76 return 0;77}78 79static int ts72xx_wdt_settimeout(struct watchdog_device *wdd, unsigned int to)80{81 struct ts72xx_wdt_priv *priv = watchdog_get_drvdata(wdd);82 83 if (to == 1) {84 priv->regval = TS72XX_WDT_CTRL_1SEC;85 } else if (to == 2) {86 priv->regval = TS72XX_WDT_CTRL_2SEC;87 } else if (to <= 4) {88 priv->regval = TS72XX_WDT_CTRL_4SEC;89 to = 4;90 } else {91 priv->regval = TS72XX_WDT_CTRL_8SEC;92 if (to <= 8)93 to = 8;94 }95 96 wdd->timeout = to;97 98 if (watchdog_active(wdd)) {99 ts72xx_wdt_stop(wdd);100 ts72xx_wdt_start(wdd);101 }102 103 return 0;104}105 106static const struct watchdog_info ts72xx_wdt_ident = {107 .options = WDIOF_KEEPALIVEPING |108 WDIOF_SETTIMEOUT |109 WDIOF_MAGICCLOSE,110 .firmware_version = 1,111 .identity = "TS-72XX WDT",112};113 114static const struct watchdog_ops ts72xx_wdt_ops = {115 .owner = THIS_MODULE,116 .start = ts72xx_wdt_start,117 .stop = ts72xx_wdt_stop,118 .ping = ts72xx_wdt_ping,119 .set_timeout = ts72xx_wdt_settimeout,120};121 122static int ts72xx_wdt_probe(struct platform_device *pdev)123{124 struct device *dev = &pdev->dev;125 struct ts72xx_wdt_priv *priv;126 struct watchdog_device *wdd;127 int ret;128 129 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);130 if (!priv)131 return -ENOMEM;132 133 priv->control_reg = devm_platform_ioremap_resource(pdev, 0);134 if (IS_ERR(priv->control_reg))135 return PTR_ERR(priv->control_reg);136 137 priv->feed_reg = devm_platform_ioremap_resource(pdev, 1);138 if (IS_ERR(priv->feed_reg))139 return PTR_ERR(priv->feed_reg);140 141 wdd = &priv->wdd;142 wdd->info = &ts72xx_wdt_ident;143 wdd->ops = &ts72xx_wdt_ops;144 wdd->min_timeout = 1;145 wdd->max_hw_heartbeat_ms = 8000;146 wdd->parent = dev;147 148 watchdog_set_nowayout(wdd, nowayout);149 150 wdd->timeout = TS72XX_WDT_DEFAULT_TIMEOUT;151 watchdog_init_timeout(wdd, timeout, dev);152 153 watchdog_set_drvdata(wdd, priv);154 155 ret = devm_watchdog_register_device(dev, wdd);156 if (ret)157 return ret;158 159 dev_info(dev, "TS-72xx Watchdog driver\n");160 161 return 0;162}163 164static const struct of_device_id ts72xx_wdt_of_ids[] = {165 { .compatible = "technologic,ts7200-wdt" },166 { /* sentinel */ }167};168MODULE_DEVICE_TABLE(of, ts72xx_wdt_of_ids);169 170static struct platform_driver ts72xx_wdt_driver = {171 .probe = ts72xx_wdt_probe,172 .driver = {173 .name = "ts72xx-wdt",174 .of_match_table = ts72xx_wdt_of_ids,175 },176};177 178module_platform_driver(ts72xx_wdt_driver);179 180MODULE_AUTHOR("Mika Westerberg <mika.westerberg@iki.fi>");181MODULE_DESCRIPTION("TS-72xx SBC Watchdog");182MODULE_LICENSE("GPL");183MODULE_ALIAS("platform:ts72xx-wdt");184