[WATCHDOG] Add support for the Avionic Design Xanthos watchdog timer.
authorThierry Reding <thierry.reding@avionic-design.de>
Wed, 23 Sep 2009 11:49:52 +0000 (13:49 +0200)
committerWim Van Sebroeck <wim@iguana.be>
Fri, 25 Sep 2009 08:38:16 +0000 (08:38 +0000)
This patch adds support for the watchdog timer on Avionic Design Xanthos
boards.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
drivers/watchdog/Kconfig
drivers/watchdog/Makefile
drivers/watchdog/adx_wdt.c [new file with mode: 0644]

index ff3eb8ff6bd798913bf7dcac8e13b8b2ec5a8f0a..3711b888d482f13f2284d5c25c16a9d84d1ecbab 100644 (file)
@@ -282,6 +282,13 @@ config NUC900_WATCHDOG
          To compile this driver as a module, choose M here: the
          module will be called nuc900_wdt.
 
+config ADX_WATCHDOG
+       tristate "Avionic Design Xanthos watchdog"
+       depends on ARCH_PXA_ADX
+       help
+         Say Y here if you want support for the watchdog timer on Avionic
+         Design Xanthos boards.
+
 # AVR32 Architecture
 
 config AT32AP700X_WDT
index 348b3b862c9940e0cedf54ebd6426574e5f41d82..699199b1baa6baf24d31f8e0355631ab84b1060d 100644 (file)
@@ -45,6 +45,7 @@ obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
 obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
 obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
 obj-$(CONFIG_NUC900_WATCHDOG) += nuc900_wdt.o
+obj-$(CONFIG_ADX_WATCHDOG) += adx_wdt.o
 
 # AVR32 Architecture
 obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/adx_wdt.c b/drivers/watchdog/adx_wdt.c
new file mode 100644 (file)
index 0000000..77afb0a
--- /dev/null
@@ -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 <linux/fs.h>
+#include <linux/io.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+#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 <thierry.reding@avionic-design.de>");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);