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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>
313 lines
7.4 KiB
C
313 lines
7.4 KiB
C
/*
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* Watchdog driver for the wm831x PMICs
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*
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* Copyright (C) 2009 Wolfson Microelectronics
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/slab.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/uaccess.h>
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#include <linux/gpio.h>
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#include <linux/mfd/wm831x/core.h>
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#include <linux/mfd/wm831x/pdata.h>
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#include <linux/mfd/wm831x/watchdog.h>
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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 wm831x_wdt_drvdata {
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struct watchdog_device wdt;
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struct wm831x *wm831x;
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struct mutex lock;
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int update_gpio;
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int update_state;
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};
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/* We can't use the sub-second values here but they're included
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* for completeness. */
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static struct {
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unsigned int time; /* Seconds */
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u16 val; /* WDOG_TO value */
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} wm831x_wdt_cfgs[] = {
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{ 1, 2 },
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{ 2, 3 },
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{ 4, 4 },
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{ 8, 5 },
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{ 16, 6 },
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{ 32, 7 },
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{ 33, 7 }, /* Actually 32.768s so include both, others round down */
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};
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static int wm831x_wdt_start(struct watchdog_device *wdt_dev)
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{
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struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
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struct wm831x *wm831x = driver_data->wm831x;
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int ret;
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mutex_lock(&driver_data->lock);
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ret = wm831x_reg_unlock(wm831x);
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if (ret == 0) {
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ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
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WM831X_WDOG_ENA, WM831X_WDOG_ENA);
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wm831x_reg_lock(wm831x);
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} else {
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dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
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ret);
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}
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mutex_unlock(&driver_data->lock);
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return ret;
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}
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static int wm831x_wdt_stop(struct watchdog_device *wdt_dev)
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{
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struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
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struct wm831x *wm831x = driver_data->wm831x;
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int ret;
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mutex_lock(&driver_data->lock);
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ret = wm831x_reg_unlock(wm831x);
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if (ret == 0) {
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ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
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WM831X_WDOG_ENA, 0);
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wm831x_reg_lock(wm831x);
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} else {
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dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
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ret);
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}
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mutex_unlock(&driver_data->lock);
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return ret;
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}
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static int wm831x_wdt_ping(struct watchdog_device *wdt_dev)
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{
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struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
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struct wm831x *wm831x = driver_data->wm831x;
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int ret;
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u16 reg;
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mutex_lock(&driver_data->lock);
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if (driver_data->update_gpio) {
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gpio_set_value_cansleep(driver_data->update_gpio,
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driver_data->update_state);
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driver_data->update_state = !driver_data->update_state;
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ret = 0;
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goto out;
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}
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reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
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if (!(reg & WM831X_WDOG_RST_SRC)) {
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dev_err(wm831x->dev, "Hardware watchdog update unsupported\n");
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ret = -EINVAL;
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goto out;
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}
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reg |= WM831X_WDOG_RESET;
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ret = wm831x_reg_unlock(wm831x);
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if (ret == 0) {
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ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
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wm831x_reg_lock(wm831x);
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} else {
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dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
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ret);
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}
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out:
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mutex_unlock(&driver_data->lock);
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return ret;
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}
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static int wm831x_wdt_set_timeout(struct watchdog_device *wdt_dev,
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unsigned int timeout)
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{
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struct wm831x_wdt_drvdata *driver_data = watchdog_get_drvdata(wdt_dev);
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struct wm831x *wm831x = driver_data->wm831x;
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int ret, i;
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for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
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if (wm831x_wdt_cfgs[i].time == timeout)
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break;
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if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
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return -EINVAL;
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ret = wm831x_reg_unlock(wm831x);
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if (ret == 0) {
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ret = wm831x_set_bits(wm831x, WM831X_WATCHDOG,
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WM831X_WDOG_TO_MASK,
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wm831x_wdt_cfgs[i].val);
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wm831x_reg_lock(wm831x);
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} else {
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dev_err(wm831x->dev, "Failed to unlock security key: %d\n",
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ret);
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}
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wdt_dev->timeout = timeout;
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return ret;
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}
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static const struct watchdog_info wm831x_wdt_info = {
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE,
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.identity = "WM831x Watchdog",
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};
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static const struct watchdog_ops wm831x_wdt_ops = {
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.owner = THIS_MODULE,
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.start = wm831x_wdt_start,
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.stop = wm831x_wdt_stop,
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.ping = wm831x_wdt_ping,
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.set_timeout = wm831x_wdt_set_timeout,
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};
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static int wm831x_wdt_probe(struct platform_device *pdev)
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{
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struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
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struct wm831x_pdata *chip_pdata = dev_get_platdata(pdev->dev.parent);
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struct wm831x_watchdog_pdata *pdata;
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struct wm831x_wdt_drvdata *driver_data;
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struct watchdog_device *wm831x_wdt;
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int reg, ret, i;
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ret = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
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if (ret < 0) {
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dev_err(wm831x->dev, "Failed to read watchdog status: %d\n",
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ret);
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goto err;
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}
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reg = ret;
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if (reg & WM831X_WDOG_DEBUG)
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dev_warn(wm831x->dev, "Watchdog is paused\n");
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driver_data = devm_kzalloc(&pdev->dev, sizeof(*driver_data),
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GFP_KERNEL);
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if (!driver_data) {
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ret = -ENOMEM;
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goto err;
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}
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mutex_init(&driver_data->lock);
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driver_data->wm831x = wm831x;
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wm831x_wdt = &driver_data->wdt;
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wm831x_wdt->info = &wm831x_wdt_info;
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wm831x_wdt->ops = &wm831x_wdt_ops;
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wm831x_wdt->parent = &pdev->dev;
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watchdog_set_nowayout(wm831x_wdt, nowayout);
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watchdog_set_drvdata(wm831x_wdt, driver_data);
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reg = wm831x_reg_read(wm831x, WM831X_WATCHDOG);
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reg &= WM831X_WDOG_TO_MASK;
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for (i = 0; i < ARRAY_SIZE(wm831x_wdt_cfgs); i++)
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if (wm831x_wdt_cfgs[i].val == reg)
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break;
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if (i == ARRAY_SIZE(wm831x_wdt_cfgs))
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dev_warn(wm831x->dev,
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"Unknown watchdog timeout: %x\n", reg);
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else
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wm831x_wdt->timeout = wm831x_wdt_cfgs[i].time;
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/* Apply any configuration */
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if (chip_pdata)
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pdata = chip_pdata->watchdog;
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else
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pdata = NULL;
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if (pdata) {
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reg &= ~(WM831X_WDOG_SECACT_MASK | WM831X_WDOG_PRIMACT_MASK |
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WM831X_WDOG_RST_SRC);
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reg |= pdata->primary << WM831X_WDOG_PRIMACT_SHIFT;
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reg |= pdata->secondary << WM831X_WDOG_SECACT_SHIFT;
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reg |= pdata->software << WM831X_WDOG_RST_SRC_SHIFT;
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if (pdata->update_gpio) {
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ret = devm_gpio_request_one(&pdev->dev,
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pdata->update_gpio,
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GPIOF_OUT_INIT_LOW,
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"Watchdog update");
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if (ret < 0) {
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dev_err(wm831x->dev,
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"Failed to request update GPIO: %d\n",
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ret);
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goto err;
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}
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driver_data->update_gpio = pdata->update_gpio;
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/* Make sure the watchdog takes hardware updates */
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reg |= WM831X_WDOG_RST_SRC;
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}
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ret = wm831x_reg_unlock(wm831x);
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if (ret == 0) {
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ret = wm831x_reg_write(wm831x, WM831X_WATCHDOG, reg);
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wm831x_reg_lock(wm831x);
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} else {
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dev_err(wm831x->dev,
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"Failed to unlock security key: %d\n", ret);
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goto err;
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}
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}
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ret = watchdog_register_device(&driver_data->wdt);
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if (ret != 0) {
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dev_err(wm831x->dev, "watchdog_register_device() failed: %d\n",
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ret);
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goto err;
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}
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platform_set_drvdata(pdev, driver_data);
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return 0;
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err:
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return ret;
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}
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static int wm831x_wdt_remove(struct platform_device *pdev)
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{
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struct wm831x_wdt_drvdata *driver_data = platform_get_drvdata(pdev);
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watchdog_unregister_device(&driver_data->wdt);
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return 0;
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}
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static struct platform_driver wm831x_wdt_driver = {
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.probe = wm831x_wdt_probe,
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.remove = wm831x_wdt_remove,
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.driver = {
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.name = "wm831x-watchdog",
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},
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};
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module_platform_driver(wm831x_wdt_driver);
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MODULE_AUTHOR("Mark Brown");
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MODULE_DESCRIPTION("WM831x Watchdog");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm831x-watchdog");
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