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![Pratyush Anand](/assets/img/avatar_default.png)
/sys/class/watchdog/watchdogn/device/modalias can help to identify the driver/module for a given watchdog node. However, many wdt devices do not set their parent and so, we do not see an entry for device in sysfs for such devices. This patch fixes parent of watchdog_device so that /sys/class/watchdog/watchdogn/device is populated. Exceptions: booke, diag288, octeon, softdog and w83627hf -- They do not have any parent. Not sure, how we can identify driver for these devices. Signed-off-by: Pratyush Anand <panand@redhat.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: Guenter Roeck <linux@roeck-us.net> Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Acked-by: Lee Jones <lee.jones@linaro.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Maxime Coquelin <maxime.coquelin@st.com> Acked-by: Thierry Reding <treding@nvidia.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
284 lines
6.5 KiB
C
284 lines
6.5 KiB
C
/*
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* Driver for watchdog device controlled through GPIO-line
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*
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* Author: 2013, Alexander Shiyan <shc_work@mail.ru>
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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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#include <linux/err.h>
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/of_gpio.h>
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#include <linux/platform_device.h>
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#include <linux/reboot.h>
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#include <linux/watchdog.h>
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#define SOFT_TIMEOUT_MIN 1
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#define SOFT_TIMEOUT_DEF 60
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#define SOFT_TIMEOUT_MAX 0xffff
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enum {
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HW_ALGO_TOGGLE,
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HW_ALGO_LEVEL,
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};
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struct gpio_wdt_priv {
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int gpio;
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bool active_low;
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bool state;
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bool always_running;
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bool armed;
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unsigned int hw_algo;
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unsigned int hw_margin;
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unsigned long last_jiffies;
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struct notifier_block notifier;
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struct timer_list timer;
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struct watchdog_device wdd;
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};
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static void gpio_wdt_disable(struct gpio_wdt_priv *priv)
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{
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gpio_set_value_cansleep(priv->gpio, !priv->active_low);
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/* Put GPIO back to tristate */
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if (priv->hw_algo == HW_ALGO_TOGGLE)
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gpio_direction_input(priv->gpio);
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}
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static void gpio_wdt_hwping(unsigned long data)
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{
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struct watchdog_device *wdd = (struct watchdog_device *)data;
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struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
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if (priv->armed && time_after(jiffies, priv->last_jiffies +
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msecs_to_jiffies(wdd->timeout * 1000))) {
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dev_crit(wdd->dev, "Timer expired. System will reboot soon!\n");
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return;
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}
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/* Restart timer */
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mod_timer(&priv->timer, jiffies + priv->hw_margin);
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switch (priv->hw_algo) {
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case HW_ALGO_TOGGLE:
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/* Toggle output pin */
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priv->state = !priv->state;
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gpio_set_value_cansleep(priv->gpio, priv->state);
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break;
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case HW_ALGO_LEVEL:
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/* Pulse */
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gpio_set_value_cansleep(priv->gpio, !priv->active_low);
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udelay(1);
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gpio_set_value_cansleep(priv->gpio, priv->active_low);
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break;
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}
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}
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static void gpio_wdt_start_impl(struct gpio_wdt_priv *priv)
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{
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priv->state = priv->active_low;
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gpio_direction_output(priv->gpio, priv->state);
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priv->last_jiffies = jiffies;
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gpio_wdt_hwping((unsigned long)&priv->wdd);
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}
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static int gpio_wdt_start(struct watchdog_device *wdd)
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{
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struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
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gpio_wdt_start_impl(priv);
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priv->armed = true;
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return 0;
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}
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static int gpio_wdt_stop(struct watchdog_device *wdd)
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{
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struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
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priv->armed = false;
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if (!priv->always_running) {
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mod_timer(&priv->timer, 0);
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gpio_wdt_disable(priv);
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}
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return 0;
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}
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static int gpio_wdt_ping(struct watchdog_device *wdd)
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{
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struct gpio_wdt_priv *priv = watchdog_get_drvdata(wdd);
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priv->last_jiffies = jiffies;
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return 0;
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}
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static int gpio_wdt_set_timeout(struct watchdog_device *wdd, unsigned int t)
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{
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wdd->timeout = t;
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return gpio_wdt_ping(wdd);
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}
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static int gpio_wdt_notify_sys(struct notifier_block *nb, unsigned long code,
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void *unused)
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{
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struct gpio_wdt_priv *priv = container_of(nb, struct gpio_wdt_priv,
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notifier);
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mod_timer(&priv->timer, 0);
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switch (code) {
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case SYS_HALT:
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case SYS_POWER_OFF:
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gpio_wdt_disable(priv);
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break;
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default:
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break;
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}
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return NOTIFY_DONE;
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}
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static const struct watchdog_info gpio_wdt_ident = {
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.options = WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
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WDIOF_SETTIMEOUT,
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.identity = "GPIO Watchdog",
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};
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static const struct watchdog_ops gpio_wdt_ops = {
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.owner = THIS_MODULE,
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.start = gpio_wdt_start,
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.stop = gpio_wdt_stop,
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.ping = gpio_wdt_ping,
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.set_timeout = gpio_wdt_set_timeout,
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};
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static int gpio_wdt_probe(struct platform_device *pdev)
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{
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struct gpio_wdt_priv *priv;
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enum of_gpio_flags flags;
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unsigned int hw_margin;
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unsigned long f = 0;
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const char *algo;
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int ret;
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->gpio = of_get_gpio_flags(pdev->dev.of_node, 0, &flags);
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if (!gpio_is_valid(priv->gpio))
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return priv->gpio;
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priv->active_low = flags & OF_GPIO_ACTIVE_LOW;
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ret = of_property_read_string(pdev->dev.of_node, "hw_algo", &algo);
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if (ret)
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return ret;
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if (!strcmp(algo, "toggle")) {
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priv->hw_algo = HW_ALGO_TOGGLE;
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f = GPIOF_IN;
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} else if (!strcmp(algo, "level")) {
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priv->hw_algo = HW_ALGO_LEVEL;
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f = priv->active_low ? GPIOF_OUT_INIT_HIGH : GPIOF_OUT_INIT_LOW;
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} else {
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return -EINVAL;
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}
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ret = devm_gpio_request_one(&pdev->dev, priv->gpio, f,
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dev_name(&pdev->dev));
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if (ret)
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return ret;
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ret = of_property_read_u32(pdev->dev.of_node,
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"hw_margin_ms", &hw_margin);
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if (ret)
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return ret;
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/* Disallow values lower than 2 and higher than 65535 ms */
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if (hw_margin < 2 || hw_margin > 65535)
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return -EINVAL;
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/* Use safe value (1/2 of real timeout) */
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priv->hw_margin = msecs_to_jiffies(hw_margin / 2);
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priv->always_running = of_property_read_bool(pdev->dev.of_node,
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"always-running");
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watchdog_set_drvdata(&priv->wdd, priv);
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priv->wdd.info = &gpio_wdt_ident;
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priv->wdd.ops = &gpio_wdt_ops;
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priv->wdd.min_timeout = SOFT_TIMEOUT_MIN;
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priv->wdd.max_timeout = SOFT_TIMEOUT_MAX;
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priv->wdd.parent = &pdev->dev;
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if (watchdog_init_timeout(&priv->wdd, 0, &pdev->dev) < 0)
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priv->wdd.timeout = SOFT_TIMEOUT_DEF;
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setup_timer(&priv->timer, gpio_wdt_hwping, (unsigned long)&priv->wdd);
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ret = watchdog_register_device(&priv->wdd);
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if (ret)
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return ret;
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priv->notifier.notifier_call = gpio_wdt_notify_sys;
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ret = register_reboot_notifier(&priv->notifier);
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if (ret)
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goto error_unregister;
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if (priv->always_running)
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gpio_wdt_start_impl(priv);
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return 0;
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error_unregister:
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watchdog_unregister_device(&priv->wdd);
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return ret;
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}
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static int gpio_wdt_remove(struct platform_device *pdev)
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{
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struct gpio_wdt_priv *priv = platform_get_drvdata(pdev);
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del_timer_sync(&priv->timer);
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unregister_reboot_notifier(&priv->notifier);
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watchdog_unregister_device(&priv->wdd);
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return 0;
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}
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static const struct of_device_id gpio_wdt_dt_ids[] = {
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{ .compatible = "linux,wdt-gpio", },
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{ }
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};
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MODULE_DEVICE_TABLE(of, gpio_wdt_dt_ids);
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static struct platform_driver gpio_wdt_driver = {
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.driver = {
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.name = "gpio-wdt",
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.of_match_table = gpio_wdt_dt_ids,
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},
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.probe = gpio_wdt_probe,
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.remove = gpio_wdt_remove,
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};
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#ifdef CONFIG_GPIO_WATCHDOG_ARCH_INITCALL
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static int __init gpio_wdt_init(void)
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{
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return platform_driver_register(&gpio_wdt_driver);
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}
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arch_initcall(gpio_wdt_init);
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#else
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module_platform_driver(gpio_wdt_driver);
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#endif
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MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
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MODULE_DESCRIPTION("GPIO Watchdog");
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MODULE_LICENSE("GPL");
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