]> err.no Git - linux-2.6/commitdiff
[WATCHDOG] Watchdog driver for AT32AP700X devices
authorHans-Christian Egtvedt <hcegtvedt@atmel.com>
Thu, 7 Jun 2007 23:06:41 +0000 (16:06 -0700)
committerWim Van Sebroeck <wim@iguana.be>
Sun, 10 Jun 2007 19:49:20 +0000 (19:49 +0000)
Add support for the built in watchdog in AT32AP700X devices.

Tested on AT32AP7000 and ATSTK1000.

Hardware documentation can be found in the AT32AP7000 datasheet.

Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drivers/char/watchdog/Kconfig
drivers/char/watchdog/Makefile
drivers/char/watchdog/at32ap700x_wdt.c [new file with mode: 0644]

index 53f5538c0c05e69d056f7cbf8c48c57f1e821074..520afb8e523479d662b54c84ed5dd19dbf062804 100644 (file)
@@ -187,6 +187,26 @@ config PNX4008_WATCHDOG
 
          Say N if you are unsure.
 
+# AVR32 Architecture
+
+config AT32AP700X_WDT
+       tristate "AT32AP700x watchdog"
+       depends on WATCHDOG && CPU_AT32AP7000
+       help
+         Watchdog timer embedded into AT32AP700x devices. This will reboot
+         your system when the timeout is reached.
+
+config AT32AP700X_WDT_TIMEOUT
+       int "Timeout value for AT32AP700x watchdog"
+       depends on AT32AP700X_WDT
+       default "2"
+       range 1 2
+       help
+         Sets the timeout value for the watchdog in AT32AP700x devices.
+         Limited by hardware to be 1 or 2 seconds.
+
+         Set to 2 seconds by default.
+
 # X86 (i386 + ia64 + x86_64) Architecture
 
 config ACQUIRE_WDT
index d90f649038c2bc7d87626e274affb8942c740ce3..3907ec04a4e5f2ce729b90ac732eaa7c83ec9aec 100644 (file)
@@ -36,6 +36,9 @@ obj-$(CONFIG_MPCORE_WATCHDOG) += mpcore_wdt.o
 obj-$(CONFIG_EP93XX_WATCHDOG) += ep93xx_wdt.o
 obj-$(CONFIG_PNX4008_WATCHDOG) += pnx4008_wdt.o
 
+# AVR32 Architecture
+obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
+
 # X86 (i386 + ia64 + x86_64) Architecture
 obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o
 obj-$(CONFIG_ADVANTECH_WDT) += advantechwdt.o
diff --git a/drivers/char/watchdog/at32ap700x_wdt.c b/drivers/char/watchdog/at32ap700x_wdt.c
new file mode 100644 (file)
index 0000000..036d83b
--- /dev/null
@@ -0,0 +1,313 @@
+/*
+ * Watchdog driver for Atmel AT32AP700X devices
+ *
+ * Copyright (C) 2005-2006 Atmel Corporation
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/miscdevice.h>
+#include <linux/fs.h>
+#include <linux/platform_device.h>
+#include <linux/watchdog.h>
+
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#define TIMEOUT_MIN            1
+#define TIMEOUT_DEFAULT                CONFIG_AT32AP700X_WDT_TIMEOUT
+#define TIMEOUT_MAX            2
+
+/* Watchdog registers and write/read macro */
+#define WDT_CTRL               0x00
+#define WDT_CTRL_EN               0
+#define WDT_CTRL_PSEL             8
+#define WDT_CTRL_KEY             24
+
+#define WDT_CLR                        0x04
+
+#define WDT_BIT(name)          (1 << WDT_##name)
+#define WDT_BF(name,value)     ((value) << WDT_##name)
+
+#define wdt_readl(dev,reg)                             \
+       __raw_readl((dev)->regs + WDT_##reg)
+#define wdt_writel(dev,reg,value)                      \
+       __raw_writel((value), (dev)->regs + WDT_##reg)
+
+struct wdt_at32ap700x {
+       void __iomem            *regs;
+       int                     timeout;
+       int                     users;
+       struct miscdevice       miscdev;
+};
+
+static struct wdt_at32ap700x *wdt;
+
+/*
+ * Disable the watchdog.
+ */
+static void inline at32_wdt_stop(void)
+{
+       unsigned long psel = wdt_readl(wdt, CTRL) & WDT_BF(CTRL_PSEL, 0x0f);
+       wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0x55));
+       wdt_writel(wdt, CTRL, psel | WDT_BF(CTRL_KEY, 0xaa));
+}
+
+/*
+ * Enable and reset the watchdog.
+ */
+static void inline at32_wdt_start(void)
+{
+       /* 0xf is 2^16 divider = 2 sec, 0xe is 2^15 divider = 1 sec */
+       unsigned long psel = (wdt->timeout > 1) ? 0xf : 0xe;
+
+       wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
+                       | WDT_BF(CTRL_PSEL, psel)
+                       | WDT_BF(CTRL_KEY, 0x55));
+       wdt_writel(wdt, CTRL, WDT_BIT(CTRL_EN)
+                       | WDT_BF(CTRL_PSEL, psel)
+                       | WDT_BF(CTRL_KEY, 0xaa));
+}
+
+/*
+ * Pat the watchdog timer.
+ */
+static void inline at32_wdt_pat(void)
+{
+       wdt_writel(wdt, CLR, 0x42);
+}
+
+/*
+ * Watchdog device is opened, and watchdog starts running.
+ */
+static int at32_wdt_open(struct inode *inode, struct file *file)
+{
+       if (test_and_set_bit(1, &wdt->users))
+               return -EBUSY;
+
+       at32_wdt_start();
+       return nonseekable_open(inode, file);
+}
+
+/*
+ * Close the watchdog device. If CONFIG_WATCHDOG_NOWAYOUT is _not_ defined then
+ * the watchdog is also disabled.
+ */
+static int at32_wdt_close(struct inode *inode, struct file *file)
+{
+#ifndef CONFIG_WATCHDOG_NOWAYOUT
+       at32_wdt_stop();
+#endif
+       clear_bit(1, &wdt->users);
+       return 0;
+}
+
+/*
+ * Change the watchdog time interval.
+ */
+static int at32_wdt_settimeout(int time)
+{
+       /*
+        * All counting occurs at 1 / SLOW_CLOCK (32 kHz) and max prescaler is
+        * 2 ^ 16 allowing up to 2 seconds timeout.
+        */
+       if ((time < TIMEOUT_MIN) || (time > TIMEOUT_MAX))
+               return -EINVAL;
+
+       /* Set new watchdog time. It will be used when at32_wdt_start() is called. */
+       wdt->timeout = time;
+       return 0;
+}
+
+static struct watchdog_info at32_wdt_info = {
+       .identity       = "at32ap700x watchdog",
+       .options        = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+};
+
+/*
+ * Handle commands from user-space.
+ */
+static int at32_wdt_ioctl(struct inode *inode, struct file *file,
+               unsigned int cmd, unsigned long arg)
+{
+       int ret = -ENOTTY;
+       int time;
+       void __user *argp = (void __user *)arg;
+       int __user *p = argp;
+
+       switch(cmd) {
+       case WDIOC_KEEPALIVE:
+               at32_wdt_pat();
+               ret = 0;
+               break;
+       case WDIOC_GETSUPPORT:
+               ret = copy_to_user(argp, &at32_wdt_info,
+                               sizeof(at32_wdt_info)) ? -EFAULT : 0;
+               break;
+       case WDIOC_SETTIMEOUT:
+               ret = get_user(time, p);
+               if (ret)
+                       break;
+               ret = at32_wdt_settimeout(time);
+               if (ret)
+                       break;
+               /* Enable new time value */
+               at32_wdt_start();
+               /* fall through */
+       case WDIOC_GETTIMEOUT:
+               ret = put_user(wdt->timeout, p);
+               break;
+       case WDIOC_GETSTATUS: /* fall through */
+       case WDIOC_GETBOOTSTATUS:
+               ret = put_user(0, p);
+               break;
+       case WDIOC_SETOPTIONS:
+               ret = get_user(time, p);
+               if (ret)
+                       break;
+               if (time & WDIOS_DISABLECARD)
+                       at32_wdt_stop();
+               if (time & WDIOS_ENABLECARD)
+                       at32_wdt_start();
+               ret = 0;
+               break;
+       }
+
+       return ret;
+}
+
+static ssize_t at32_wdt_write(struct file *file, const char *data, size_t len, loff_t *ppos)
+{
+       at32_wdt_pat();
+       return len;
+}
+
+static const struct file_operations at32_wdt_fops = {
+       .owner          = THIS_MODULE,
+       .llseek         = no_llseek,
+       .ioctl          = at32_wdt_ioctl,
+       .open           = at32_wdt_open,
+       .release        = at32_wdt_close,
+       .write          = at32_wdt_write,
+};
+
+static int __init at32_wdt_probe(struct platform_device *pdev)
+{
+       struct resource *regs;
+       int ret;
+
+       if (wdt) {
+               dev_dbg(&pdev->dev, "only 1 wdt instance supported.\n");
+               return -EBUSY;
+       }
+
+       regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       if (!regs) {
+               dev_dbg(&pdev->dev, "missing mmio resource\n");
+               return -ENXIO;
+       }
+
+       wdt = kzalloc(sizeof(struct wdt_at32ap700x), GFP_KERNEL);
+       if (!wdt) {
+               dev_dbg(&pdev->dev, "no memory for wdt structure\n");
+               return -ENOMEM;
+       }
+
+       wdt->regs = ioremap(regs->start, regs->end - regs->start + 1);
+       wdt->users = 0;
+       wdt->miscdev.minor = WATCHDOG_MINOR;
+       wdt->miscdev.name = "watchdog";
+       wdt->miscdev.fops = &at32_wdt_fops;
+
+       if (at32_wdt_settimeout(TIMEOUT_DEFAULT)) {
+               at32_wdt_settimeout(TIMEOUT_MAX);
+               dev_dbg(&pdev->dev,
+                       "default timeout invalid, set to %d sec.\n",
+                       TIMEOUT_MAX);
+       }
+
+       ret = misc_register(&wdt->miscdev);
+       if (ret) {
+               dev_dbg(&pdev->dev, "failed to register wdt miscdev\n");
+               goto err_register;
+       }
+
+       platform_set_drvdata(pdev, wdt);
+       wdt->miscdev.parent = &pdev->dev;
+       dev_info(&pdev->dev, "AT32AP700X WDT at 0x%p\n", wdt->regs);
+
+       return 0;
+
+err_register:
+       kfree(wdt);
+       wdt = NULL;
+       return ret;
+}
+
+static int __exit at32_wdt_remove(struct platform_device *pdev)
+{
+       if (wdt && platform_get_drvdata(pdev) == wdt) {
+               misc_deregister(&wdt->miscdev);
+               kfree(wdt);
+               wdt = NULL;
+               platform_set_drvdata(pdev, NULL);
+       }
+
+       return 0;
+}
+
+static void at32_wdt_shutdown(struct platform_device *pdev)
+{
+       at32_wdt_stop();
+}
+
+#ifdef CONFIG_PM
+static int at32_wdt_suspend(struct platform_device *pdev, pm_message_t message)
+{
+       at32_wdt_stop();
+       return 0;
+}
+
+static int at32_wdt_resume(struct platform_device *pdev)
+{
+       if (wdt->users)
+               at32_wdt_start();
+       return 0;
+}
+#endif
+
+static struct platform_driver at32_wdt_driver = {
+       .remove         = __exit_p(at32_wdt_remove),
+#ifdef CONFIG_PM
+       .suspend        = at32_wdt_suspend,
+       .resume         = at32_wdt_resume,
+#endif
+       .driver         = {
+               .name   = "at32_wdt",
+               .owner  = THIS_MODULE,
+       },
+       .shutdown       = at32_wdt_shutdown,
+};
+
+static int __init at32_wdt_init(void)
+{
+       return platform_driver_probe(&at32_wdt_driver, at32_wdt_probe);
+}
+module_init(at32_wdt_init);
+
+static void __exit at32_wdt_exit(void)
+{
+       platform_driver_unregister(&at32_wdt_driver);
+}
+module_exit(at32_wdt_exit);
+
+MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
+MODULE_DESCRIPTION("Watchdog driver for Atmel AT32AP700X");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);