266 lines
6.2 KiB
C
266 lines
6.2 KiB
C
/*
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* Copyright (C) 2016 National Instruments Corp.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/acpi.h>
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#include <linux/bitops.h>
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#include <linux/device.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#define LOCK 0xA5
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#define UNLOCK 0x5A
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#define WDT_CTRL_RESET_EN BIT(7)
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#define WDT_RELOAD_PORT_EN BIT(7)
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#define WDT_CTRL 1
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#define WDT_RELOAD_CTRL 2
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#define WDT_PRESET_PRESCALE 4
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#define WDT_REG_LOCK 5
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#define WDT_COUNT 6
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#define WDT_RELOAD_PORT 7
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#define WDT_MIN_TIMEOUT 1
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#define WDT_MAX_TIMEOUT 464
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#define WDT_DEFAULT_TIMEOUT 80
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#define WDT_MAX_COUNTER 15
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static unsigned int timeout;
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module_param(timeout, uint, 0);
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MODULE_PARM_DESC(timeout,
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"Watchdog timeout in seconds. (default="
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__MODULE_STRING(WDT_DEFAULT_TIMEOUT) ")");
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static bool nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, bool, 0);
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MODULE_PARM_DESC(nowayout,
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"Watchdog cannot be stopped once started. (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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struct nic7018_wdt {
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u16 io_base;
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u32 period;
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struct watchdog_device wdd;
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};
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struct nic7018_config {
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u32 period;
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u8 divider;
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};
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static const struct nic7018_config nic7018_configs[] = {
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{ 2, 4 },
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{ 32, 5 },
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};
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static inline u32 nic7018_timeout(u32 period, u8 counter)
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{
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return period * counter - period / 2;
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}
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static const struct nic7018_config *nic7018_get_config(u32 timeout,
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u8 *counter)
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{
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const struct nic7018_config *config;
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u8 count;
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if (timeout < 30 && timeout != 16) {
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config = &nic7018_configs[0];
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count = timeout / 2 + 1;
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} else {
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config = &nic7018_configs[1];
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count = DIV_ROUND_UP(timeout + 16, 32);
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if (count > WDT_MAX_COUNTER)
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count = WDT_MAX_COUNTER;
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}
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*counter = count;
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return config;
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}
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static int nic7018_set_timeout(struct watchdog_device *wdd,
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unsigned int timeout)
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{
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struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
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const struct nic7018_config *config;
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u8 counter;
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config = nic7018_get_config(timeout, &counter);
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outb(counter << 4 | config->divider,
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wdt->io_base + WDT_PRESET_PRESCALE);
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wdd->timeout = nic7018_timeout(config->period, counter);
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wdt->period = config->period;
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return 0;
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}
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static int nic7018_start(struct watchdog_device *wdd)
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{
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struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
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u8 control;
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nic7018_set_timeout(wdd, wdd->timeout);
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control = inb(wdt->io_base + WDT_RELOAD_CTRL);
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outb(control | WDT_RELOAD_PORT_EN, wdt->io_base + WDT_RELOAD_CTRL);
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outb(1, wdt->io_base + WDT_RELOAD_PORT);
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control = inb(wdt->io_base + WDT_CTRL);
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outb(control | WDT_CTRL_RESET_EN, wdt->io_base + WDT_CTRL);
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return 0;
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}
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static int nic7018_stop(struct watchdog_device *wdd)
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{
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struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
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outb(0, wdt->io_base + WDT_CTRL);
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outb(0, wdt->io_base + WDT_RELOAD_CTRL);
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outb(0xF0, wdt->io_base + WDT_PRESET_PRESCALE);
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return 0;
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}
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static int nic7018_ping(struct watchdog_device *wdd)
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{
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struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
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outb(1, wdt->io_base + WDT_RELOAD_PORT);
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return 0;
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}
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static unsigned int nic7018_get_timeleft(struct watchdog_device *wdd)
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{
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struct nic7018_wdt *wdt = watchdog_get_drvdata(wdd);
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u8 count;
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count = inb(wdt->io_base + WDT_COUNT) & 0xF;
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if (!count)
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return 0;
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return nic7018_timeout(wdt->period, count);
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}
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static const struct watchdog_info nic7018_wdd_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "NIC7018 Watchdog",
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};
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static const struct watchdog_ops nic7018_wdd_ops = {
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.owner = THIS_MODULE,
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.start = nic7018_start,
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.stop = nic7018_stop,
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.ping = nic7018_ping,
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.set_timeout = nic7018_set_timeout,
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.get_timeleft = nic7018_get_timeleft,
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};
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static int nic7018_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct watchdog_device *wdd;
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struct nic7018_wdt *wdt;
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struct resource *io_rc;
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int ret;
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wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL);
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if (!wdt)
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return -ENOMEM;
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platform_set_drvdata(pdev, wdt);
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io_rc = platform_get_resource(pdev, IORESOURCE_IO, 0);
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if (!io_rc) {
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dev_err(dev, "missing IO resources\n");
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return -EINVAL;
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}
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if (!devm_request_region(dev, io_rc->start, resource_size(io_rc),
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KBUILD_MODNAME)) {
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dev_err(dev, "failed to get IO region\n");
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return -EBUSY;
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}
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wdt->io_base = io_rc->start;
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wdd = &wdt->wdd;
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wdd->info = &nic7018_wdd_info;
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wdd->ops = &nic7018_wdd_ops;
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wdd->min_timeout = WDT_MIN_TIMEOUT;
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wdd->max_timeout = WDT_MAX_TIMEOUT;
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wdd->timeout = WDT_DEFAULT_TIMEOUT;
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wdd->parent = dev;
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watchdog_set_drvdata(wdd, wdt);
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watchdog_set_nowayout(wdd, nowayout);
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ret = watchdog_init_timeout(wdd, timeout, dev);
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if (ret)
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dev_warn(dev, "unable to set timeout value, using default\n");
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/* Unlock WDT register */
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outb(UNLOCK, wdt->io_base + WDT_REG_LOCK);
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ret = watchdog_register_device(wdd);
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if (ret) {
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outb(LOCK, wdt->io_base + WDT_REG_LOCK);
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dev_err(dev, "failed to register watchdog\n");
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return ret;
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}
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dev_dbg(dev, "io_base=0x%04X, timeout=%d, nowayout=%d\n",
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wdt->io_base, timeout, nowayout);
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return 0;
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}
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static int nic7018_remove(struct platform_device *pdev)
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{
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struct nic7018_wdt *wdt = platform_get_drvdata(pdev);
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watchdog_unregister_device(&wdt->wdd);
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/* Lock WDT register */
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outb(LOCK, wdt->io_base + WDT_REG_LOCK);
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return 0;
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}
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static const struct acpi_device_id nic7018_device_ids[] = {
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{"NIC7018", 0},
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{"", 0},
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};
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MODULE_DEVICE_TABLE(acpi, nic7018_device_ids);
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static struct platform_driver watchdog_driver = {
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.probe = nic7018_probe,
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.remove = nic7018_remove,
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.driver = {
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.name = KBUILD_MODNAME,
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.acpi_match_table = ACPI_PTR(nic7018_device_ids),
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},
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};
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module_platform_driver(watchdog_driver);
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MODULE_DESCRIPTION("National Instruments NIC7018 Watchdog driver");
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MODULE_AUTHOR("Hui Chun Ong <hui.chun.ong@ni.com>");
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MODULE_LICENSE("GPL");
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