lkml.org 
[lkml]   [2009]   [Aug]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH v2] Add watchdog driver for w90p910
Dear Wim,

Maybe I did not know well regarding linux watchdog driver before, but, now Via your help
and researching further the timer used in watchdog driver,I rewrite my wdt driver, Now, I
can set any time interval in userspace rather than setting the time level. :)


Signed-off-by: Wan ZongShun <mcuos.com@gmail.com>

---
drivers/watchdog/Kconfig | 9 +
drivers/watchdog/Makefile | 1 +
drivers/watchdog/w90p910_wdt.c | 330 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 340 insertions(+), 0 deletions(-)
create mode 100644 drivers/watchdog/w90p910_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index b1ccc04..fba4b91 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -266,6 +266,15 @@ config STMP3XXX_WATCHDOG
To compile this driver as a module, choose M here: the
module will be called stmp3xxx_wdt.

+config W90P910_WATCHDOG
+ tristate "Nuvoton W90P910 watchdog"
+ depends on ARCH_W90X900
+ help
+ Say Y here if to include support for the watchdog timer
+ for the Nuvoton W90P910 SoC.
+ To compile this driver as a module, choose M here: the
+ module will be called w90p910_wdt.
+
# AVR32 Architecture

config AT32AP700X_WDT
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 3d77429..ecc05b4 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_DAVINCI_WATCHDOG) += davinci_wdt.o
obj-$(CONFIG_ORION_WATCHDOG) += orion_wdt.o
obj-$(CONFIG_COH901327_WATCHDOG) += coh901327_wdt.o
obj-$(CONFIG_STMP3XXX_WATCHDOG) += stmp3xxx_wdt.o
+obj-$(CONFIG_W90P910_WATCHDOG) += w90p910_wdt.o

# AVR32 Architecture
obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o
diff --git a/drivers/watchdog/w90p910_wdt.c b/drivers/watchdog/w90p910_wdt.c
new file mode 100644
index 0000000..4e954c3
--- /dev/null
+++ b/drivers/watchdog/w90p910_wdt.c
@@ -0,0 +1,330 @@
+/*
+ * Copyright (c) 2009 Nuvoton technology corporation.
+ *
+ * Wan ZongShun <mcuos.com@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation;version 2 of the License.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/kernel.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+#include <linux/types.h>
+#include <linux/watchdog.h>
+#include <linux/uaccess.h>
+
+#define REG_WTCR 0x1c
+#define WTCLK (0x01 << 10)
+#define WTE (0x01 << 7) /*wdt enable*/
+#define WTISBIT (0x04)
+#define WTIS (0x03 << 4)
+#define WTIF (0x01 << 3)
+#define WTRF (0x01 << 2)
+#define WTRE (0x01 << 1)
+#define WTR 0x01
+#define WDT_TIMEOUT (HZ/2)
+#define WDT_HEARTBEAT 15
+#define WDT_HW_TIMEOUT 0x02 /* 4 seconds */
+
+static int heartbeat = WDT_HEARTBEAT;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
+ "(default = " __MODULE_STRING(WDT_HEARTBEAT) ")");
+
+static int nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct w90p910_wdt {
+ struct resource *res;
+ struct clk *wdt_clock;
+ struct platform_device *pdev;
+ void __iomem *wdt_base;
+ char expect_close;
+ struct timer_list timer;
+ spinlock_t wdt_lock;
+ unsigned long next_heartbeat;
+};
+
+static unsigned long w90p910wdt_busy;
+struct w90p910_wdt *w90p910_wdt;
+
+static inline void w90p910_wdt_keepalive(void)
+{
+ unsigned int val;
+
+ spin_lock(&w90p910_wdt->wdt_lock);
+
+ val = __raw_readl(w90p910_wdt->wdt_base + REG_WTCR);
+ val |= (WTR | WTIF);
+ __raw_writel(val, w90p910_wdt->wdt_base + REG_WTCR);
+
+ spin_unlock(&w90p910_wdt->wdt_lock);
+}
+
+static inline void w90p910_wdt_start(void)
+{
+ unsigned int val;
+
+ spin_lock(&w90p910_wdt->wdt_lock);
+
+ val = __raw_readl(w90p910_wdt->wdt_base + REG_WTCR);
+ val |= (WTRE | WTE | WTR | WTCLK | WTIF);
+ __raw_writel(val, w90p910_wdt->wdt_base + REG_WTCR);
+
+ spin_unlock(&w90p910_wdt->wdt_lock);
+}
+
+static int w90p910_wdt_settimeout(unsigned int timeout)
+{
+ unsigned int val;
+ spin_lock(&w90p910_wdt->wdt_lock);
+
+ val = __raw_readl(w90p910_wdt->wdt_base + REG_WTCR);
+ val &= ~WTIS;
+ val |= (timeout << 0x04);
+ __raw_writel(val, w90p910_wdt->wdt_base + REG_WTCR);
+
+ spin_unlock(&w90p910_wdt->wdt_lock);
+
+ return 0;
+}
+
+static int w90p910_wdt_open(struct inode *inode, struct file *file)
+{
+
+ if (test_and_set_bit(0, &w90p910wdt_busy))
+ return -EBUSY;
+
+ w90p910_wdt_start();
+ w90p910_wdt_settimeout(WDT_HW_TIMEOUT);
+
+ w90p910_wdt->next_heartbeat = jiffies + heartbeat * HZ;
+ mod_timer(&w90p910_wdt->timer, jiffies + WDT_TIMEOUT);
+
+ return nonseekable_open(inode, file);
+}
+
+static int w90p910_wdt_close(struct inode *inode, struct file *file)
+{
+ clear_bit(0, &w90p910wdt_busy);
+
+ if (!w90p910_wdt->expect_close)
+ del_timer(&w90p910_wdt->timer);
+
+ w90p910_wdt->expect_close = 0;
+ return 0;
+}
+
+static struct watchdog_info w90p910_wdt_info = {
+ .identity = "w90p910 watchdog",
+ .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static long w90p910_wdt_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+ int __user *p = argp;
+ int new_value;
+
+ switch (cmd) {
+ case WDIOC_GETSUPPORT:
+ return copy_to_user(argp, &w90p910_wdt_info,
+ sizeof(w90p910_wdt_info)) ? -EFAULT : 0;
+ case WDIOC_GETSTATUS:
+ case WDIOC_GETBOOTSTATUS:
+ return put_user(0, p);
+
+ case WDIOC_KEEPALIVE:
+ w90p910_wdt->next_heartbeat = jiffies + heartbeat * HZ;
+ return 0;
+
+ case WDIOC_SETTIMEOUT:
+ if (get_user(new_value, p))
+ return -EFAULT;
+
+ heartbeat = new_value;
+ w90p910_wdt->next_heartbeat = jiffies + heartbeat * HZ;
+
+ return put_user(new_value, p);
+ case WDIOC_GETTIMEOUT:
+ return put_user(heartbeat, p);
+ default:
+ return -ENOTTY;
+ }
+}
+
+static ssize_t w90p910_wdt_write(struct file *file, const char __user *data,
+ size_t len, loff_t *ppos)
+{
+ /* Scan for magic character */
+ if (!nowayout) {
+ size_t i;
+
+ w90p910_wdt->expect_close = 0;
+
+ for (i = 0; i < len; i++) {
+ char c;
+ if (get_user(c, data + i))
+ return -EFAULT;
+ if (c == 'V') {
+ w90p910_wdt->expect_close = 42;
+ break;
+ }
+ }
+ }
+
+ w90p910_wdt->next_heartbeat = jiffies + heartbeat * HZ;
+ return len;
+}
+
+static void w90p910_ping(unsigned long data)
+{
+ if (time_before(jiffies, w90p910_wdt->next_heartbeat) ||
+ (!nowayout && !w90p910wdt_busy)) {
+ w90p910_wdt_keepalive();
+ mod_timer(&w90p910_wdt->timer, jiffies + WDT_TIMEOUT);
+ } else
+ dev_warn(&w90p910_wdt->pdev->dev, "Will reset the machine !\n");
+}
+
+static const struct file_operations w90p910wdt_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .unlocked_ioctl = w90p910_wdt_ioctl,
+ .open = w90p910_wdt_open,
+ .release = w90p910_wdt_close,
+ .write = w90p910_wdt_write,
+};
+
+static struct miscdevice w90p910wdt_miscdev = {
+ .minor = WATCHDOG_MINOR,
+ .name = "watchdog",
+ .fops = &w90p910wdt_fops,
+};
+
+static int __devinit w90p910wdt_probe(struct platform_device *pdev)
+{
+ int ret = 0;
+
+ w90p910_wdt = kzalloc(sizeof(struct w90p910_wdt), GFP_KERNEL);
+ if (!w90p910_wdt)
+ return -ENOMEM;
+
+ w90p910_wdt->pdev = pdev;
+
+ spin_lock_init(&w90p910_wdt->wdt_lock);
+
+ w90p910_wdt->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (w90p910_wdt->res == NULL) {
+ dev_err(&pdev->dev, "no memory resource specified\n");
+ ret = -ENOENT;
+ goto err_get;
+ }
+
+ if (!request_mem_region(w90p910_wdt->res->start,
+ resource_size(w90p910_wdt->res), pdev->name)) {
+ dev_err(&pdev->dev, "failed to get memory region\n");
+ ret = -ENOENT;
+ goto err_get;
+ }
+
+ w90p910_wdt->wdt_base = ioremap(w90p910_wdt->res->start,
+ resource_size(w90p910_wdt->res));
+ if (w90p910_wdt->wdt_base == NULL) {
+ dev_err(&pdev->dev, "failed to ioremap() region\n");
+ ret = -EINVAL;
+ goto err_req;
+ }
+
+ w90p910_wdt->wdt_clock = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(w90p910_wdt->wdt_clock)) {
+ dev_err(&pdev->dev, "failed to find watchdog clock source\n");
+ ret = PTR_ERR(w90p910_wdt->wdt_clock);
+ goto err_map;
+ }
+
+ clk_enable(w90p910_wdt->wdt_clock);
+
+ if (misc_register(&w90p910wdt_miscdev)) {
+ dev_err(&pdev->dev, "err register miscdev on minor=%d (%d)\n",
+ WATCHDOG_MINOR, ret);
+ goto err_clk;
+ }
+
+ setup_timer(&w90p910_wdt->timer, w90p910_ping, 0);
+
+ return 0;
+
+err_clk:
+ clk_disable(w90p910_wdt->wdt_clock);
+ clk_put(w90p910_wdt->wdt_clock);
+err_map:
+ iounmap(w90p910_wdt->wdt_base);
+err_req:
+ release_mem_region(w90p910_wdt->res->start,
+ resource_size(w90p910_wdt->res));
+err_get:
+ kfree(w90p910_wdt);
+ return ret;
+}
+
+static int __devexit w90p910wdt_remove(struct platform_device *pdev)
+{
+ misc_deregister(&w90p910wdt_miscdev);
+
+ clk_disable(w90p910_wdt->wdt_clock);
+ clk_put(w90p910_wdt->wdt_clock);
+
+ iounmap(w90p910_wdt->wdt_base);
+
+ release_mem_region(w90p910_wdt->res->start,
+ resource_size(w90p910_wdt->res));
+
+ kfree(w90p910_wdt);
+
+ return 0;
+}
+
+static struct platform_driver w90p910wdt_driver = {
+ .probe = w90p910wdt_probe,
+ .remove = __devexit_p(w90p910wdt_remove),
+ .driver = {
+ .name = "w90p910-wdt",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init w90p910_wdt_init(void)
+{
+ return platform_driver_register(&w90p910wdt_driver);
+}
+
+static void __exit w90p910_wdt_exit(void)
+{
+ platform_driver_unregister(&w90p910wdt_driver);
+}
+
+module_init(w90p910_wdt_init);
+module_exit(w90p910_wdt_exit);
+
+MODULE_AUTHOR("Wan ZongShun <mcuos.com@gmail.com>");
+MODULE_DESCRIPTION("Watchdog driver for W90P910");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
+MODULE_ALIAS("platform:w90p910-wdt");
--
1.5.6.3



\
 
 \ /
  Last update: 2009-08-05 15:25    [W:0.110 / U:0.148 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site