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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Copyright (C) 2016 National Instruments Corp.4 */5 6#include <linux/acpi.h>7#include <linux/bitops.h>8#include <linux/device.h>9#include <linux/io.h>10#include <linux/module.h>11#include <linux/platform_device.h>12#include <linux/watchdog.h>13 14#define LOCK 0xA515#define UNLOCK 0x5A16 17#define WDT_CTRL_RESET_EN BIT(7)18#define WDT_RELOAD_PORT_EN BIT(7)19 20#define WDT_CTRL 121#define WDT_RELOAD_CTRL 222#define WDT_PRESET_PRESCALE 423#define WDT_REG_LOCK 524#define WDT_COUNT 625#define WDT_RELOAD_PORT 726 27#define WDT_MIN_TIMEOUT 128#define WDT_MAX_TIMEOUT 46429#define WDT_DEFAULT_TIMEOUT 8030 31#define WDT_MAX_COUNTER 1532 33static unsigned int timeout;34module_param(timeout, uint, 0);35MODULE_PARM_DESC(timeout,36 "Watchdog timeout in seconds. (default="37 __MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");38 39static bool nowayout = WATCHDOG_NOWAYOUT;40module_param(nowayout, bool, 0);41MODULE_PARM_DESC(nowayout,42 "Watchdog cannot be stopped once started. (default="43 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");44 45struct nic7018_wdt {46 u16 io_base;47 u32 period;48 struct watchdog_device wdd;49};50 51struct nic7018_config {52 u32 period;53 u8 divider;54};55 56static const struct nic7018_config nic7018_configs[] = {57 { 2, 4 },58 { 32, 5 },59};60 61static inline u32 nic7018_timeout(u32 period, u8 counter)62{63 return period * counter - period / 2;64}65 66static const struct nic7018_config *nic7018_get_config(u32 timeout,67 u8 *counter)68{69 const struct nic7018_config *config;70 u8 count;71 72 if (timeout < 30 && timeout != 16) {73 config = &nic7018_configs[0];74 count = timeout / 2 + 1;75 } else {76 config = &nic7018_configs[1];77 count = DIV_ROUND_UP(timeout + 16, 32);78 79 if (count > WDT_MAX_COUNTER)80 count = WDT_MAX_COUNTER;81 }82 *counter = count;83 return config;84}85 86static int nic7018_set_timeout(struct watchdog_device *wdd,87 unsigned int timeout)88{89 struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);90 const struct nic7018_config *config;91 u8 counter;92 93 config = nic7018_get_config(timeout, &counter);94 95 outb(counter << 4 | config->divider,96 wdt->io_base + WDT_PRESET_PRESCALE);97 98 wdd->timeout = nic7018_timeout(config->period, counter);99 wdt->period = config->period;100 101 return 0;102}103 104static int nic7018_start(struct watchdog_device *wdd)105{106 struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);107 u8 control;108 109 nic7018_set_timeout(wdd, wdd->timeout);110 111 control = inb(wdt->io_base + WDT_RELOAD_CTRL);112 outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);113 114 outb(1, wdt->io_base + WDT_RELOAD_PORT);115 116 control = inb(wdt->io_base + WDT_CTRL);117 outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);118 119 return 0;120}121 122static int nic7018_stop(struct watchdog_device *wdd)123{124 struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);125 126 outb(0, wdt->io_base + WDT_CTRL);127 outb(0, wdt->io_base + WDT_RELOAD_CTRL);128 outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);129 130 return 0;131}132 133static int nic7018_ping(struct watchdog_device *wdd)134{135 struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);136 137 outb(1, wdt->io_base + WDT_RELOAD_PORT);138 139 return 0;140}141 142static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd)143{144 struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);145 u8 count;146 147 count = inb(wdt->io_base + WDT_COUNT) & 0xF;148 if (!count)149 return 0;150 151 return nic7018_timeout(wdt->period, count);152}153 154static const struct watchdog_info nic7018_wdd_info = {155 .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,156 .identity = "NIC7018 Watchdog",157};158 159static const struct watchdog_ops nic7018_wdd_ops = {160 .owner = THIS_MODULE,161 .start = nic7018_start,162 .stop = nic7018_stop,163 .ping = nic7018_ping,164 .set_timeout = nic7018_set_timeout,165 .get_timeleft = nic7018_get_timeleft,166};167 168static int nic7018_probe(struct platform_device *pdev)169{170 struct device *dev = &pdev->dev;171 struct watchdog_device *wdd;172 struct nic7018_wdt *wdt;173 struct resource *io_rc;174 int ret;175 176 wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);177 if (!wdt)178 return -ENOMEM;179 180 platform_set_drvdata(pdev, wdt);181 182 io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);183 if (!io_rc) {184 dev_err(dev, "missing IO resources\n");185 return -EINVAL;186 }187 188 if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),189 KBUILD_MODNAME)) {190 dev_err(dev, "failed to get IO region\n");191 return -EBUSY;192 }193 194 wdt->io_base = io_rc->start;195 wdd = &wdt->wdd;196 wdd->info = &nic7018_wdd_info;197 wdd->ops = &nic7018_wdd_ops;198 wdd->min_timeout = WDT_MIN_TIMEOUT;199 wdd->max_timeout = WDT_MAX_TIMEOUT;200 wdd->timeout = WDT_DEFAULT_TIMEOUT;201 wdd->parent = dev;202 203 watchdog_set_drvdata(wdd, wdt);204 watchdog_set_nowayout(wdd, nowayout);205 watchdog_init_timeout(wdd, timeout, dev);206 207 /* Unlock WDT register */208 outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);209 210 ret = watchdog_register_device(wdd);211 if (ret) {212 outb(LOCK, wdt->io_base + WDT_REG_LOCK);213 return ret;214 }215 216 dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",217 wdt->io_base, timeout, nowayout);218 return 0;219}220 221static void nic7018_remove(struct platform_device *pdev)222{223 struct nic7018_wdt *wdt = platform_get_drvdata(pdev);224 225 watchdog_unregister_device(&wdt->wdd);226 227 /* Lock WDT register */228 outb(LOCK, wdt->io_base + WDT_REG_LOCK);229}230 231static const struct acpi_device_id nic7018_device_ids[] = {232 {"NIC7018", 0},233 {"", 0},234};235MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);236 237static struct platform_driver watchdog_driver = {238 .probe = nic7018_probe,239 .remove_new = nic7018_remove,240 .driver = {241 .name = KBUILD_MODNAME,242 .acpi_match_table = ACPI_PTR(nic7018_device_ids),243 },244};245 246module_platform_driver(watchdog_driver);247 248MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver");249MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");250MODULE_LICENSE("GPL");251