From 38461c5c084ec9119f481f27629d84283733b82a Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Wed, 23 Sep 2009 13:49:52 +0200 Subject: [WATCHDOG] Add support for the Avionic Design Xanthos watchdog timer. This patch adds support for the watchdog timer on Avionic Design Xanthos boards. Signed-off-by: Thierry Reding Acked-by: Russell King Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/adx_wdt.c | 354 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 354 insertions(+) create mode 100644 drivers/watchdog/adx_wdt.c (limited to 'drivers/watchdog/adx_wdt.c') diff --git a/drivers/watchdog/adx_wdt.c b/drivers/watchdog/adx_wdt.c new file mode 100644 index 000000000000..77afb0acc500 --- /dev/null +++ b/drivers/watchdog/adx_wdt.c @@ -0,0 +1,354 @@ +/* + * Copyright (C) 2008-2009 Avionic Design GmbH + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define WATCHDOG_NAME "adx-wdt" + +/* register offsets */ +#define ADX_WDT_CONTROL 0x00 +#define ADX_WDT_CONTROL_ENABLE (1 << 0) +#define ADX_WDT_CONTROL_nRESET (1 << 1) +#define ADX_WDT_TIMEOUT 0x08 + +static struct platform_device *adx_wdt_dev; +static unsigned long driver_open; + +#define WDT_STATE_STOP 0 +#define WDT_STATE_START 1 + +struct adx_wdt { + void __iomem *base; + unsigned long timeout; + unsigned int state; + unsigned int wake; + spinlock_t lock; +}; + +static struct watchdog_info adx_wdt_info = { + .identity = "Avionic Design Xanthos Watchdog", + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, +}; + +static void adx_wdt_start_locked(struct adx_wdt *wdt) +{ + u32 ctrl; + + ctrl = readl(wdt->base + ADX_WDT_CONTROL); + ctrl |= ADX_WDT_CONTROL_ENABLE; + writel(ctrl, wdt->base + ADX_WDT_CONTROL); + wdt->state = WDT_STATE_START; +} + +static void adx_wdt_start(struct adx_wdt *wdt) +{ + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + adx_wdt_start_locked(wdt); + spin_unlock_irqrestore(&wdt->lock, flags); +} + +static void adx_wdt_stop_locked(struct adx_wdt *wdt) +{ + u32 ctrl; + + ctrl = readl(wdt->base + ADX_WDT_CONTROL); + ctrl &= ~ADX_WDT_CONTROL_ENABLE; + writel(ctrl, wdt->base + ADX_WDT_CONTROL); + wdt->state = WDT_STATE_STOP; +} + +static void adx_wdt_stop(struct adx_wdt *wdt) +{ + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + adx_wdt_stop_locked(wdt); + spin_unlock_irqrestore(&wdt->lock, flags); +} + +static void adx_wdt_set_timeout(struct adx_wdt *wdt, unsigned long seconds) +{ + unsigned long timeout = seconds * 1000; + unsigned long flags; + unsigned int state; + + spin_lock_irqsave(&wdt->lock, flags); + state = wdt->state; + adx_wdt_stop_locked(wdt); + writel(timeout, wdt->base + ADX_WDT_TIMEOUT); + + if (state == WDT_STATE_START) + adx_wdt_start_locked(wdt); + + wdt->timeout = timeout; + spin_unlock_irqrestore(&wdt->lock, flags); +} + +static void adx_wdt_get_timeout(struct adx_wdt *wdt, unsigned long *seconds) +{ + *seconds = wdt->timeout / 1000; +} + +static void adx_wdt_keepalive(struct adx_wdt *wdt) +{ + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + writel(wdt->timeout, wdt->base + ADX_WDT_TIMEOUT); + spin_unlock_irqrestore(&wdt->lock, flags); +} + +static int adx_wdt_open(struct inode *inode, struct file *file) +{ + struct adx_wdt *wdt = platform_get_drvdata(adx_wdt_dev); + + if (test_and_set_bit(0, &driver_open)) + return -EBUSY; + + file->private_data = wdt; + adx_wdt_set_timeout(wdt, 30); + adx_wdt_start(wdt); + + return nonseekable_open(inode, file); +} + +static int adx_wdt_release(struct inode *inode, struct file *file) +{ + struct adx_wdt *wdt = file->private_data; + + adx_wdt_stop(wdt); + clear_bit(0, &driver_open); + + return 0; +} + +static long adx_wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct adx_wdt *wdt = file->private_data; + void __user *argp = (void __user *)arg; + unsigned long __user *p = argp; + unsigned long seconds = 0; + unsigned int options; + long ret = -EINVAL; + + switch (cmd) { + case WDIOC_GETSUPPORT: + if (copy_to_user(argp, &adx_wdt_info, sizeof(adx_wdt_info))) + return -EFAULT; + else + return 0; + + case WDIOC_GETSTATUS: + case WDIOC_GETBOOTSTATUS: + return put_user(0, p); + + case WDIOC_KEEPALIVE: + adx_wdt_keepalive(wdt); + return 0; + + case WDIOC_SETTIMEOUT: + if (get_user(seconds, p)) + return -EFAULT; + + adx_wdt_set_timeout(wdt, seconds); + + /* fallthrough */ + case WDIOC_GETTIMEOUT: + adx_wdt_get_timeout(wdt, &seconds); + return put_user(seconds, p); + + case WDIOC_SETOPTIONS: + if (copy_from_user(&options, argp, sizeof(options))) + return -EFAULT; + + if (options & WDIOS_DISABLECARD) { + adx_wdt_stop(wdt); + ret = 0; + } + + if (options & WDIOS_ENABLECARD) { + adx_wdt_start(wdt); + ret = 0; + } + + return ret; + + default: + break; + } + + return -ENOTTY; +} + +static ssize_t adx_wdt_write(struct file *file, const char __user *data, + size_t len, loff_t *ppos) +{ + struct adx_wdt *wdt = file->private_data; + + if (len) + adx_wdt_keepalive(wdt); + + return len; +} + +static const struct file_operations adx_wdt_fops = { + .owner = THIS_MODULE, + .llseek = no_llseek, + .open = adx_wdt_open, + .release = adx_wdt_release, + .unlocked_ioctl = adx_wdt_ioctl, + .write = adx_wdt_write, +}; + +static struct miscdevice adx_wdt_miscdev = { + .minor = WATCHDOG_MINOR, + .name = "watchdog", + .fops = &adx_wdt_fops, +}; + +static int __devinit adx_wdt_probe(struct platform_device *pdev) +{ + struct resource *res; + struct adx_wdt *wdt; + int ret = 0; + u32 ctrl; + + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) { + dev_err(&pdev->dev, "cannot allocate WDT structure\n"); + return -ENOMEM; + } + + spin_lock_init(&wdt->lock); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) { + dev_err(&pdev->dev, "cannot obtain I/O memory region\n"); + return -ENXIO; + } + + res = devm_request_mem_region(&pdev->dev, res->start, + res->end - res->start + 1, res->name); + if (!res) { + dev_err(&pdev->dev, "cannot request I/O memory region\n"); + return -ENXIO; + } + + wdt->base = devm_ioremap_nocache(&pdev->dev, res->start, + res->end - res->start + 1); + if (!wdt->base) { + dev_err(&pdev->dev, "cannot remap I/O memory region\n"); + return -ENXIO; + } + + /* disable watchdog and reboot on timeout */ + ctrl = readl(wdt->base + ADX_WDT_CONTROL); + ctrl &= ~ADX_WDT_CONTROL_ENABLE; + ctrl &= ~ADX_WDT_CONTROL_nRESET; + writel(ctrl, wdt->base + ADX_WDT_CONTROL); + + platform_set_drvdata(pdev, wdt); + adx_wdt_dev = pdev; + + ret = misc_register(&adx_wdt_miscdev); + if (ret) { + dev_err(&pdev->dev, "cannot register miscdev on minor %d " + "(err=%d)\n", WATCHDOG_MINOR, ret); + return ret; + } + + return 0; +} + +static int __devexit adx_wdt_remove(struct platform_device *pdev) +{ + struct adx_wdt *wdt = platform_get_drvdata(pdev); + + misc_deregister(&adx_wdt_miscdev); + adx_wdt_stop(wdt); + platform_set_drvdata(pdev, NULL); + + return 0; +} + +static void adx_wdt_shutdown(struct platform_device *pdev) +{ + struct adx_wdt *wdt = platform_get_drvdata(pdev); + adx_wdt_stop(wdt); +} + +#ifdef CONFIG_PM +static int adx_wdt_suspend(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct adx_wdt *wdt = platform_get_drvdata(pdev); + + wdt->wake = (wdt->state == WDT_STATE_START) ? 1 : 0; + adx_wdt_stop(wdt); + + return 0; +} + +static int adx_wdt_resume(struct device *dev) +{ + struct platform_device *pdev = to_platform_device(dev); + struct adx_wdt *wdt = platform_get_drvdata(pdev); + + if (wdt->wake) + adx_wdt_start(wdt); + + return 0; +} + +static struct dev_pm_ops adx_wdt_pm_ops = { + .suspend = adx_wdt_suspend, + .resume = adx_wdt_resume, +}; + +# define ADX_WDT_PM_OPS (&adx_wdt_pm_ops) +#else +# define ADX_WDT_PM_OPS NULL +#endif + +static struct platform_driver adx_wdt_driver = { + .probe = adx_wdt_probe, + .remove = __devexit_p(adx_wdt_remove), + .shutdown = adx_wdt_shutdown, + .driver = { + .name = WATCHDOG_NAME, + .owner = THIS_MODULE, + .pm = ADX_WDT_PM_OPS, + }, +}; + +static int __init adx_wdt_init(void) +{ + return platform_driver_register(&adx_wdt_driver); +} + +static void __exit adx_wdt_exit(void) +{ + platform_driver_unregister(&adx_wdt_driver); +} + +module_init(adx_wdt_init); +module_exit(adx_wdt_exit); + +MODULE_DESCRIPTION("Avionic Design Xanthos Watchdog Driver"); +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Thierry Reding "); +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR); -- cgit v1.2.3