[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

Watchdog details can be found in ARM Cortex A9 reference manual at:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
---
 drivers/watchdog/Kconfig        |    7 +
 drivers/watchdog/Makefile       |    1 +
 drivers/watchdog/cortexa9_wdt.c |  414 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 422 insertions(+), 0 deletions(-)
 create mode 100755 drivers/watchdog/cortexa9_wdt.c

diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
index 0bf5020..b5c0f6f 100644
--- a/drivers/watchdog/Kconfig
+++ b/drivers/watchdog/Kconfig
@@ -73,6 +73,13 @@ config WM8350_WATCHDOG
 
 # ARM Architecture
 
+config ARM_CORTEXA9_WATCHDOG
+	tristate "ARM CortexA9 Watchdog"
+	depends on ARM_AMBA
+	help
+	  Watchdog timer present with ARM Cortex A9 processor. This will reboot
+	  your system when the timeout is reached.
+
 config AT91RM9200_WATCHDOG
 	tristate "AT91RM9200 watchdog"
 	depends on ARCH_AT91RM9200
diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
index 5e3cb95..7704efc 100644
--- a/drivers/watchdog/Makefile
+++ b/drivers/watchdog/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
 # ALPHA Architecture
 
 # ARM Architecture
+obj-$(CONFIG_ARM_CORTEXA9_WATCHDOG) += cortexa9_wdt.o
 obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
 obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
 obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
diff --git a/drivers/watchdog/cortexa9_wdt.c b/drivers/watchdog/cortexa9_wdt.c
new file mode 100755
index 0000000..f50ec64
--- /dev/null
+++ b/drivers/watchdog/cortexa9_wdt.c
@@ -0,0 +1,414 @@
+/*
+ * drivers/char/watchdog/cortexa9-wdt.c
+ *
+ * Watchdog driver for watchdog module present with ARM CORTEX A9
+ *
+ * Copyright (C) 2010 ST Microelectronics
+ * Viresh Kumar<viresh.kumar@st.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+#include <linux/watchdog.h>
+
+/* default timeout in seconds */
+#define DEFAULT_TIMEOUT		60
+
+#define MODULE_NAME		"cortexa9-wdt"
+
+/* watchdog register offsets and masks */
+#define WDTLOAD			0x000
+	#define LOAD_MIN	0x00000000
+	#define LOAD_MAX	0xFFFFFFFF
+#define WDTCOUNTER		0x004
+#define WDTCONTROL		0x008
+	/* control register masks */
+	#define WDT_ENB		(1 << 0)
+	#define WDT_ARLD_ENB	(1 << 1)	/* Autoreload enable */
+	#define WDT_IRQ_ENB	(1 << 2)
+	#define WDT_MODE	(1 << 3)
+	#define WDT_PRESCALE(x)	((x) << 8)
+	#define PRESCALE_MIN	0x00
+	#define PRESCALE_MAX	0xFF
+#define WDTINTSTS		0x00C
+	#define INT_MASK	0x1
+#define WDTRSTSTS		0x010
+	#define RST_MASK	0x1
+#define WDTDISABLE		0x014
+	#define DISABLE_VAL1	0x12345678
+	#define DISABLE_VAL2	0x87654321
+
+/**
+ * struct cortexa9_wdt: cortex a9 wdt device structure
+ *
+ * lock: spin lock protecting dev structure and io access
+ * base: base address of wdt
+ * clk: clock structure of wdt
+ * pdev: platform device structure of wdt
+ * boot_status: boot time status of wdt
+ * status: current status of wdt
+ * prescale: prescale value to be set for current timeout
+ * load_val: load value to be set for current timeout
+ * timeout: current programmed timeout
+ */
+struct cortexa9_wdt {
+	spinlock_t			lock;
+	void __iomem			*base;
+	struct clk			*clk;
+	struct platform_device		*pdev;
+	unsigned long			boot_status;
+	unsigned long			status;
+	#define WDT_BUSY		0
+	#define WDT_CAN_BE_CLOSED	1
+	unsigned int			prescale;
+	unsigned int			load_val;
+	unsigned int			timeout;
+};
+
+/* local variables */
+static struct cortexa9_wdt *wdt;
+static int nowayout = WATCHDOG_NOWAYOUT;
+
+/* binary search */
+static inline void bsearch(u32 *var, u32 var_start, u32 var_end,
+		const u64 param, const u32 timeout, u32 rate)
+{
+	u64 tmp = 0;
+
+	/* get the lowest var value that can satisfy our requirement */
+	while (var_start < var_end) {
+		tmp = var_start;
+		tmp += var_end;
+		tmp = div_u64(tmp, 2);
+		if (timeout > div_u64((param + 1) * (tmp + 1), rate)) {
+			if (var_start == tmp)
+				break;
+			else
+				var_start = tmp;
+		} else {
+			if (var_end == tmp)
+				break;
+			else
+				var_end = tmp;
+		}
+	}
+	*var = tmp;
+}
+
+/*
+ * This routine finds the most appropriate prescale and load value for input
+ * timout value
+ */
+static void wdt_config(unsigned int timeout)
+{
+	unsigned int psc, rate;
+	u64 load = 0;
+
+	rate = clk_get_rate(wdt->clk);
+
+	/* get appropriate value of psc and load */
+	bsearch(&psc, PRESCALE_MIN, PRESCALE_MAX, LOAD_MAX, timeout, rate);
+	bsearch((u32 *)&load, LOAD_MIN, LOAD_MAX, psc, timeout, rate);
+
+	spin_lock(&wdt->lock);
+	wdt->prescale = psc;
+	wdt->load_val = load;
+
+	/* roundup timeout to closest positive integer value */
+	wdt->timeout = div_u64((psc + 1) * (load + 1) + (rate / 2), rate);
+	spin_unlock(&wdt->lock);
+}
+
+static void wdt_enable(void)
+{
+	u32 val;
+
+	spin_lock(&wdt->lock);
+
+	writel(wdt->load_val, wdt->base + WDTLOAD);
+	val = WDT_MODE | WDT_PRESCALE(wdt->prescale) | WDT_ENB;
+	writel(val, wdt->base + WDTCONTROL);
+
+	spin_unlock(&wdt->lock);
+}
+
+static void wdt_disable(void)
+{
+	spin_lock(&wdt->lock);
+
+	/* firstly we need to put watchdog in timer mode */
+	writel(DISABLE_VAL1, wdt->base + WDTDISABLE);
+	writel(DISABLE_VAL2, wdt->base + WDTDISABLE);
+
+	writel(0, wdt->base + WDTCONTROL);
+	writel(INT_MASK, wdt->base + WDTINTSTS);
+	writel(RST_MASK, wdt->base + WDTRSTSTS);
+
+	spin_unlock(&wdt->lock);
+}
+
+static ssize_t cortexa9_wdt_write(struct file *file, const char *data,
+		size_t len, loff_t *ppos)
+{
+	if (len) {
+		if (!nowayout) {
+			size_t i;
+
+			clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
+
+			for (i = 0; i != len; i++) {
+				char c;
+
+				if (get_user(c, data + i))
+					return -EFAULT;
+				if (c == 'V') {
+					set_bit(WDT_CAN_BE_CLOSED,
+							&wdt->status);
+					break;
+				}
+			}
+		}
+		wdt_enable();
+	}
+	return len;
+}
+
+static const struct watchdog_info ident = {
+	.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
+		WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
+	.identity = MODULE_NAME,
+};
+
+static long cortexa9_wdt_ioctl(struct file *file, unsigned int cmd,
+		unsigned long arg)
+{
+	int ret = -ENOTTY;
+	int timeout;
+
+	switch (cmd) {
+	case WDIOC_GETSUPPORT:
+		ret = copy_to_user((struct watchdog_info *)arg, &ident,
+				sizeof(ident)) ? -EFAULT : 0;
+		break;
+
+	case WDIOC_GETSTATUS:
+		ret = put_user(0, (int *)arg);
+		break;
+
+	case WDIOC_GETBOOTSTATUS:
+		ret = put_user(wdt->boot_status, (int *)arg);
+		break;
+
+	case WDIOC_KEEPALIVE:
+		wdt_enable();
+		ret = 0;
+		break;
+
+	case WDIOC_SETTIMEOUT:
+		ret = get_user(timeout, (int *)arg);
+		if (ret)
+			break;
+
+		wdt_config(timeout);
+
+		wdt_enable();
+		/* Fall through */
+
+	case WDIOC_GETTIMEOUT:
+		ret = put_user(wdt->timeout, (int *)arg);
+		break;
+	}
+	return ret;
+}
+
+static int cortexa9_wdt_open(struct inode *inode, struct file *file)
+{
+	int ret = 0;
+
+	if (test_and_set_bit(WDT_BUSY, &wdt->status))
+		return -EBUSY;
+
+	ret = clk_enable(wdt->clk);
+	if (ret) {
+		dev_err(&wdt->pdev->dev, "clock enable fail");
+		goto err;
+	}
+
+	wdt_enable();
+
+	/* can not be closed, once enabled */
+	clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
+	return nonseekable_open(inode, file);
+
+err:
+	clear_bit(WDT_BUSY, &wdt->status);
+	return ret;
+}
+
+static int cortexa9_wdt_release(struct inode *inode, struct file *file)
+{
+	if (!test_bit(WDT_CAN_BE_CLOSED, &wdt->status)) {
+		clear_bit(WDT_BUSY, &wdt->status);
+		dev_warn(&wdt->pdev->dev, "Device closed unexpectedly\n");
+		return 0;
+	}
+
+	wdt_disable();
+	clk_disable(wdt->clk);
+	clear_bit(WDT_BUSY, &wdt->status);
+
+	return 0;
+}
+
+static const struct file_operations cortexa9_wdt_fops = {
+	.owner = THIS_MODULE,
+	.llseek = no_llseek,
+	.write = cortexa9_wdt_write,
+	.unlocked_ioctl = cortexa9_wdt_ioctl,
+	.open = cortexa9_wdt_open,
+	.release = cortexa9_wdt_release,
+};
+
+static struct miscdevice cortexa9_wdt_miscdev = {
+	.minor = WATCHDOG_MINOR,
+	.name = "watchdog",
+	.fops = &cortexa9_wdt_fops,
+};
+
+static int __devinit cortexa9_wdt_probe(struct platform_device *pdev)
+{
+	int ret = 0;
+	struct resource *res;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res) {
+		ret = -ENOENT;
+		dev_warn(&pdev->dev, "Memory resource not defined\n");
+		goto err;
+	}
+
+	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
+		dev_warn(&pdev->dev, "Failed to get memory region resource\n");
+		ret = -ENOENT;
+		goto err;
+	}
+
+	wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
+	if (!wdt) {
+		dev_warn(&pdev->dev, "Kzalloc failed\n");
+		ret = -ENOMEM;
+		goto err_kzalloc;
+	}
+
+	wdt->clk = clk_get(&pdev->dev, NULL);
+	if (IS_ERR(wdt->clk)) {
+		dev_warn(&pdev->dev, "Clock not found\n");
+		ret = PTR_ERR(wdt->clk);
+		goto err_clk_get;
+	}
+
+	wdt->base = ioremap(res->start, resource_size(res));
+	if (!wdt->base) {
+		ret = -ENOMEM;
+		dev_warn(&pdev->dev, "ioremap fail\n");
+		goto err_ioremap;
+	}
+
+	spin_lock_init(&wdt->lock);
+	/* This checks if system booted after watchdog reset or not */
+	ret = clk_enable(wdt->clk);
+	if (!ret) {
+		wdt->boot_status = (readl(wdt->base + WDTRSTSTS) & RST_MASK) ?
+			WDIOF_CARDRESET : 0;
+		wdt_disable();
+		clk_disable(wdt->clk);
+	}
+
+	wdt->pdev = pdev;
+	wdt_config(DEFAULT_TIMEOUT);
+
+	ret = misc_register(&cortexa9_wdt_miscdev);
+	if (ret < 0) {
+		dev_warn(&pdev->dev, "cannot register misc device\n");
+		goto err_misc_register;
+	}
+
+	return 0;
+
+err_misc_register:
+	iounmap(wdt->base);
+err_ioremap:
+	clk_put(wdt->clk);
+err_clk_get:
+	kfree(wdt);
+	wdt = NULL;
+err_kzalloc:
+	release_mem_region(res->start, resource_size(res));
+err:
+	dev_err(&pdev->dev, "Probe Failed!!!\n");
+	return ret;
+}
+
+static int __devexit cortexa9_wdt_remove(struct platform_device *pdev)
+{
+	struct resource *res;
+
+	misc_deregister(&cortexa9_wdt_miscdev);
+	iounmap(wdt->base);
+	clk_put(wdt->clk);
+	kfree(wdt);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (res)
+		release_mem_region(res->start, resource_size(res));
+
+	return 0;
+}
+
+static struct platform_driver cortexa9_wdt_driver = {
+	.driver = {
+		.name = MODULE_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.probe = cortexa9_wdt_probe,
+	.remove = __devexit_p(cortexa9_wdt_remove),
+};
+
+static int __init cortexa9_wdt_init(void)
+{
+	return platform_driver_register(&cortexa9_wdt_driver);
+}
+module_init(cortexa9_wdt_init);
+
+static void __exit cortexa9_wdt_exit(void)
+{
+	platform_driver_unregister(&cortexa9_wdt_driver);
+}
+module_exit(cortexa9_wdt_exit);
+
+module_param(nowayout, int, 0);
+MODULE_PARM_DESC(nowayout,
+		"Set to 1 to keep watchdog running after device release");
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
+MODULE_DESCRIPTION("ARM CORTEX A9 Watchdog Driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
-- 
1.6.0.2

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

On 5/17/2010 3:24 PM, Viresh KUMAR wrote:
> Watchdog details can be found in ARM Cortex A9 reference manual at:
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html
> 
> Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
> ---
>  drivers/watchdog/Kconfig        |    7 +
>  drivers/watchdog/Makefile       |    1 +
>  drivers/watchdog/cortexa9_wdt.c |  414 +++++++++++++++++++++++++++++++++++++++
>  3 files changed, 422 insertions(+), 0 deletions(-)
>  create mode 100755 drivers/watchdog/cortexa9_wdt.c

Please ignore this.
mode is incorrect, i will resend it.

> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 0bf5020..b5c0f6f 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -73,6 +73,13 @@ config WM8350_WATCHDOG
>  
>  # ARM Architecture
>  
> +config ARM_CORTEXA9_WATCHDOG
> +	tristate "ARM CortexA9 Watchdog"
> +	depends on ARM_AMBA
> +	help
> +	  Watchdog timer present with ARM Cortex A9 processor. This will reboot
> +	  your system when the timeout is reached.
> +
>  config AT91RM9200_WATCHDOG
>  	tristate "AT91RM9200 watchdog"
>  	depends on ARCH_AT91RM9200
> diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile
> index 5e3cb95..7704efc 100644
> --- a/drivers/watchdog/Makefile
> +++ b/drivers/watchdog/Makefile
> @@ -25,6 +25,7 @@ obj-$(CONFIG_USBPCWATCHDOG) += pcwd_usb.o
>  # ALPHA Architecture
>  
>  # ARM Architecture
> +obj-$(CONFIG_ARM_CORTEXA9_WATCHDOG) += cortexa9_wdt.o
>  obj-$(CONFIG_AT91RM9200_WATCHDOG) += at91rm9200_wdt.o
>  obj-$(CONFIG_AT91SAM9X_WATCHDOG) += at91sam9_wdt.o
>  obj-$(CONFIG_OMAP_WATCHDOG) += omap_wdt.o
> diff --git a/drivers/watchdog/cortexa9_wdt.c b/drivers/watchdog/cortexa9_wdt.c
> new file mode 100755
> index 0000000..f50ec64
> --- /dev/null
> +++ b/drivers/watchdog/cortexa9_wdt.c
> @@ -0,0 +1,414 @@
> +/*
> + * drivers/char/watchdog/cortexa9-wdt.c
> + *
> + * Watchdog driver for watchdog module present with ARM CORTEX A9
> + *
> + * Copyright (C) 2010 ST Microelectronics
> + * Viresh Kumar<viresh.kumar@st.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/fs.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/ioport.h>
> +#include <linux/kernel.h>
> +#include <linux/math64.h>
> +#include <linux/miscdevice.h>
> +#include <linux/module.h>
> +#include <linux/moduleparam.h>
> +#include <linux/platform_device.h>
> +#include <linux/spinlock.h>
> +#include <linux/types.h>
> +#include <linux/uaccess.h>
> +#include <linux/watchdog.h>
> +
> +/* default timeout in seconds */
> +#define DEFAULT_TIMEOUT		60
> +
> +#define MODULE_NAME		"cortexa9-wdt"
> +
> +/* watchdog register offsets and masks */
> +#define WDTLOAD			0x000
> +	#define LOAD_MIN	0x00000000
> +	#define LOAD_MAX	0xFFFFFFFF
> +#define WDTCOUNTER		0x004
> +#define WDTCONTROL		0x008
> +	/* control register masks */
> +	#define WDT_ENB		(1 << 0)
> +	#define WDT_ARLD_ENB	(1 << 1)	/* Autoreload enable */
> +	#define WDT_IRQ_ENB	(1 << 2)
> +	#define WDT_MODE	(1 << 3)
> +	#define WDT_PRESCALE(x)	((x) << 8)
> +	#define PRESCALE_MIN	0x00
> +	#define PRESCALE_MAX	0xFF
> +#define WDTINTSTS		0x00C
> +	#define INT_MASK	0x1
> +#define WDTRSTSTS		0x010
> +	#define RST_MASK	0x1
> +#define WDTDISABLE		0x014
> +	#define DISABLE_VAL1	0x12345678
> +	#define DISABLE_VAL2	0x87654321
> +
> +/**
> + * struct cortexa9_wdt: cortex a9 wdt device structure
> + *
> + * lock: spin lock protecting dev structure and io access
> + * base: base address of wdt
> + * clk: clock structure of wdt
> + * pdev: platform device structure of wdt
> + * boot_status: boot time status of wdt
> + * status: current status of wdt
> + * prescale: prescale value to be set for current timeout
> + * load_val: load value to be set for current timeout
> + * timeout: current programmed timeout
> + */
> +struct cortexa9_wdt {
> +	spinlock_t			lock;
> +	void __iomem			*base;
> +	struct clk			*clk;
> +	struct platform_device		*pdev;
> +	unsigned long			boot_status;
> +	unsigned long			status;
> +	#define WDT_BUSY		0
> +	#define WDT_CAN_BE_CLOSED	1
> +	unsigned int			prescale;
> +	unsigned int			load_val;
> +	unsigned int			timeout;
> +};
> +
> +/* local variables */
> +static struct cortexa9_wdt *wdt;
> +static int nowayout = WATCHDOG_NOWAYOUT;
> +
> +/* binary search */
> +static inline void bsearch(u32 *var, u32 var_start, u32 var_end,
> +		const u64 param, const u32 timeout, u32 rate)
> +{
> +	u64 tmp = 0;
> +
> +	/* get the lowest var value that can satisfy our requirement */
> +	while (var_start < var_end) {
> +		tmp = var_start;
> +		tmp += var_end;
> +		tmp = div_u64(tmp, 2);
> +		if (timeout > div_u64((param + 1) * (tmp + 1), rate)) {
> +			if (var_start == tmp)
> +				break;
> +			else
> +				var_start = tmp;
> +		} else {
> +			if (var_end == tmp)
> +				break;
> +			else
> +				var_end = tmp;
> +		}
> +	}
> +	*var = tmp;
> +}
> +
> +/*
> + * This routine finds the most appropriate prescale and load value for input
> + * timout value
> + */
> +static void wdt_config(unsigned int timeout)
> +{
> +	unsigned int psc, rate;
> +	u64 load = 0;
> +
> +	rate = clk_get_rate(wdt->clk);
> +
> +	/* get appropriate value of psc and load */
> +	bsearch(&psc, PRESCALE_MIN, PRESCALE_MAX, LOAD_MAX, timeout, rate);
> +	bsearch((u32 *)&load, LOAD_MIN, LOAD_MAX, psc, timeout, rate);
> +
> +	spin_lock(&wdt->lock);
> +	wdt->prescale = psc;
> +	wdt->load_val = load;
> +
> +	/* roundup timeout to closest positive integer value */
> +	wdt->timeout = div_u64((psc + 1) * (load + 1) + (rate / 2), rate);
> +	spin_unlock(&wdt->lock);
> +}
> +
> +static void wdt_enable(void)
> +{
> +	u32 val;
> +
> +	spin_lock(&wdt->lock);
> +
> +	writel(wdt->load_val, wdt->base + WDTLOAD);
> +	val = WDT_MODE | WDT_PRESCALE(wdt->prescale) | WDT_ENB;
> +	writel(val, wdt->base + WDTCONTROL);
> +
> +	spin_unlock(&wdt->lock);
> +}
> +
> +static void wdt_disable(void)
> +{
> +	spin_lock(&wdt->lock);
> +
> +	/* firstly we need to put watchdog in timer mode */
> +	writel(DISABLE_VAL1, wdt->base + WDTDISABLE);
> +	writel(DISABLE_VAL2, wdt->base + WDTDISABLE);
> +
> +	writel(0, wdt->base + WDTCONTROL);
> +	writel(INT_MASK, wdt->base + WDTINTSTS);
> +	writel(RST_MASK, wdt->base + WDTRSTSTS);
> +
> +	spin_unlock(&wdt->lock);
> +}
> +
> +static ssize_t cortexa9_wdt_write(struct file *file, const char *data,
> +		size_t len, loff_t *ppos)
> +{
> +	if (len) {
> +		if (!nowayout) {
> +			size_t i;
> +
> +			clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
> +
> +			for (i = 0; i != len; i++) {
> +				char c;
> +
> +				if (get_user(c, data + i))
> +					return -EFAULT;
> +				if (c == 'V') {
> +					set_bit(WDT_CAN_BE_CLOSED,
> +							&wdt->status);
> +					break;
> +				}
> +			}
> +		}
> +		wdt_enable();
> +	}
> +	return len;
> +}
> +
> +static const struct watchdog_info ident = {
> +	.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
> +		WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> +	.identity = MODULE_NAME,
> +};
> +
> +static long cortexa9_wdt_ioctl(struct file *file, unsigned int cmd,
> +		unsigned long arg)
> +{
> +	int ret = -ENOTTY;
> +	int timeout;
> +
> +	switch (cmd) {
> +	case WDIOC_GETSUPPORT:
> +		ret = copy_to_user((struct watchdog_info *)arg, &ident,
> +				sizeof(ident)) ? -EFAULT : 0;
> +		break;
> +
> +	case WDIOC_GETSTATUS:
> +		ret = put_user(0, (int *)arg);
> +		break;
> +
> +	case WDIOC_GETBOOTSTATUS:
> +		ret = put_user(wdt->boot_status, (int *)arg);
> +		break;
> +
> +	case WDIOC_KEEPALIVE:
> +		wdt_enable();
> +		ret = 0;
> +		break;
> +
> +	case WDIOC_SETTIMEOUT:
> +		ret = get_user(timeout, (int *)arg);
> +		if (ret)
> +			break;
> +
> +		wdt_config(timeout);
> +
> +		wdt_enable();
> +		/* Fall through */
> +
> +	case WDIOC_GETTIMEOUT:
> +		ret = put_user(wdt->timeout, (int *)arg);
> +		break;
> +	}
> +	return ret;
> +}
> +
> +static int cortexa9_wdt_open(struct inode *inode, struct file *file)
> +{
> +	int ret = 0;
> +
> +	if (test_and_set_bit(WDT_BUSY, &wdt->status))
> +		return -EBUSY;
> +
> +	ret = clk_enable(wdt->clk);
> +	if (ret) {
> +		dev_err(&wdt->pdev->dev, "clock enable fail");
> +		goto err;
> +	}
> +
> +	wdt_enable();
> +
> +	/* can not be closed, once enabled */
> +	clear_bit(WDT_CAN_BE_CLOSED, &wdt->status);
> +	return nonseekable_open(inode, file);
> +
> +err:
> +	clear_bit(WDT_BUSY, &wdt->status);
> +	return ret;
> +}
> +
> +static int cortexa9_wdt_release(struct inode *inode, struct file *file)
> +{
> +	if (!test_bit(WDT_CAN_BE_CLOSED, &wdt->status)) {
> +		clear_bit(WDT_BUSY, &wdt->status);
> +		dev_warn(&wdt->pdev->dev, "Device closed unexpectedly\n");
> +		return 0;
> +	}
> +
> +	wdt_disable();
> +	clk_disable(wdt->clk);
> +	clear_bit(WDT_BUSY, &wdt->status);
> +
> +	return 0;
> +}
> +
> +static const struct file_operations cortexa9_wdt_fops = {
> +	.owner = THIS_MODULE,
> +	.llseek = no_llseek,
> +	.write = cortexa9_wdt_write,
> +	.unlocked_ioctl = cortexa9_wdt_ioctl,
> +	.open = cortexa9_wdt_open,
> +	.release = cortexa9_wdt_release,
> +};
> +
> +static struct miscdevice cortexa9_wdt_miscdev = {
> +	.minor = WATCHDOG_MINOR,
> +	.name = "watchdog",
> +	.fops = &cortexa9_wdt_fops,
> +};
> +
> +static int __devinit cortexa9_wdt_probe(struct platform_device *pdev)
> +{
> +	int ret = 0;
> +	struct resource *res;
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (!res) {
> +		ret = -ENOENT;
> +		dev_warn(&pdev->dev, "Memory resource not defined\n");
> +		goto err;
> +	}
> +
> +	if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
> +		dev_warn(&pdev->dev, "Failed to get memory region resource\n");
> +		ret = -ENOENT;
> +		goto err;
> +	}
> +
> +	wdt = kzalloc(sizeof(*wdt), GFP_KERNEL);
> +	if (!wdt) {
> +		dev_warn(&pdev->dev, "Kzalloc failed\n");
> +		ret = -ENOMEM;
> +		goto err_kzalloc;
> +	}
> +
> +	wdt->clk = clk_get(&pdev->dev, NULL);
> +	if (IS_ERR(wdt->clk)) {
> +		dev_warn(&pdev->dev, "Clock not found\n");
> +		ret = PTR_ERR(wdt->clk);
> +		goto err_clk_get;
> +	}
> +
> +	wdt->base = ioremap(res->start, resource_size(res));
> +	if (!wdt->base) {
> +		ret = -ENOMEM;
> +		dev_warn(&pdev->dev, "ioremap fail\n");
> +		goto err_ioremap;
> +	}
> +
> +	spin_lock_init(&wdt->lock);
> +	/* This checks if system booted after watchdog reset or not */
> +	ret = clk_enable(wdt->clk);
> +	if (!ret) {
> +		wdt->boot_status = (readl(wdt->base + WDTRSTSTS) & RST_MASK) ?
> +			WDIOF_CARDRESET : 0;
> +		wdt_disable();
> +		clk_disable(wdt->clk);
> +	}
> +
> +	wdt->pdev = pdev;
> +	wdt_config(DEFAULT_TIMEOUT);
> +
> +	ret = misc_register(&cortexa9_wdt_miscdev);
> +	if (ret < 0) {
> +		dev_warn(&pdev->dev, "cannot register misc device\n");
> +		goto err_misc_register;
> +	}
> +
> +	return 0;
> +
> +err_misc_register:
> +	iounmap(wdt->base);
> +err_ioremap:
> +	clk_put(wdt->clk);
> +err_clk_get:
> +	kfree(wdt);
> +	wdt = NULL;
> +err_kzalloc:
> +	release_mem_region(res->start, resource_size(res));
> +err:
> +	dev_err(&pdev->dev, "Probe Failed!!!\n");
> +	return ret;
> +}
> +
> +static int __devexit cortexa9_wdt_remove(struct platform_device *pdev)
> +{
> +	struct resource *res;
> +
> +	misc_deregister(&cortexa9_wdt_miscdev);
> +	iounmap(wdt->base);
> +	clk_put(wdt->clk);
> +	kfree(wdt);
> +
> +	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> +	if (res)
> +		release_mem_region(res->start, resource_size(res));
> +
> +	return 0;
> +}
> +
> +static struct platform_driver cortexa9_wdt_driver = {
> +	.driver = {
> +		.name = MODULE_NAME,
> +		.owner	= THIS_MODULE,
> +	},
> +	.probe = cortexa9_wdt_probe,
> +	.remove = __devexit_p(cortexa9_wdt_remove),
> +};
> +
> +static int __init cortexa9_wdt_init(void)
> +{
> +	return platform_driver_register(&cortexa9_wdt_driver);
> +}
> +module_init(cortexa9_wdt_init);
> +
> +static void __exit cortexa9_wdt_exit(void)
> +{
> +	platform_driver_unregister(&cortexa9_wdt_driver);
> +}
> +module_exit(cortexa9_wdt_exit);
> +
> +module_param(nowayout, int, 0);
> +MODULE_PARM_DESC(nowayout,
> +		"Set to 1 to keep watchdog running after device release");
> +
> +MODULE_AUTHOR("Viresh Kumar <viresh.kumar@st.com>");
> +MODULE_DESCRIPTION("ARM CORTEX A9 Watchdog Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Jassi Brar]

On Mon, May 17, 2010 at 6:54 PM, Viresh KUMAR <viresh.kumar@st.com> wrote:
> Watchdog details can be found in ARM Cortex A9 reference manual at:
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html
The link doesn't work.

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

On 5/17/2010 4:14 PM, Jassi Brar wrote:
> On Mon, May 17, 2010 at 6:54 PM, Viresh KUMAR <viresh.kumar@st.com> wrote:
>> Watchdog details can be found in ARM Cortex A9 reference manual at:
>> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html
> The link doesn't work.
> 

Sorry!! i will correct it in V2.
till then replace indix.html with index.html.

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[srinidhi kasagar]

I do not understand why a new driver is required while having similar one
for MPCore watchdog.
Please have a look at drivers/watchdog/mpcore_wdt.c

srinidhi

On Mon, May 17, 2010 at 4:54 PM, Viresh KUMAR <viresh.kumar@st.com> wrote:

> On 5/17/2010 4:14 PM, Jassi Brar wrote:
> > On Mon, May 17, 2010 at 6:54 PM, Viresh KUMAR <viresh.kumar@st.com>
> wrote:
> >> Watchdog details can be found in ARM Cortex A9 reference manual at:
> >>
> http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html
> > The link doesn't work.
> >
>
> Sorry!! i will correct it in V2.
> till then replace indix.html with index.html.
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20100518/484ac2b7/attachment.htm>

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[George G. Davis]

Hi,

On Tue, May 18, 2010 at 02:55:21PM +0530, srinidhi kasagar wrote:
> I do not understand why a new driver is required while having similar one
> for MPCore watchdog.
> Please have a look at drivers/watchdog/mpcore_wdt.c

The same thought occurred to me.  Based on a cursory glance at the Cortex-A9
MPCore and ARM11 MPCore, the per-CPU watchdogs do appear to be the same
and could use the same driver.

Any reason for creating a new driver rather than reusing the ARM11
MPCore driver?

--
Regards,
George
> 
> srinidhi
> 
> On Mon, May 17, 2010 at 4:54 PM, Viresh KUMAR <viresh.kumar@st.com> wrote:
> 
> > On 5/17/2010 4:14 PM, Jassi Brar wrote:
> > > On Mon, May 17, 2010 at 6:54 PM, Viresh KUMAR <viresh.kumar@st.com>
> > wrote:
> > >> Watchdog details can be found in ARM Cortex A9 reference manual at:
> > >>
> > http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0407e/indix.html
> > > The link doesn't work.
> > >
> >
> > Sorry!! i will correct it in V2.
> > till then replace indix.html with index.html.
> >
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> >

> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

On 5/18/2010 6:50 PM, George G. Davis wrote:
> Hi,
> 
> On Tue, May 18, 2010 at 02:55:21PM +0530, srinidhi kasagar wrote:
>> I do not understand why a new driver is required while having similar one
>> for MPCore watchdog.
>> Please have a look at drivers/watchdog/mpcore_wdt.c
> 
> The same thought occurred to me.  Based on a cursory glance at the Cortex-A9
> MPCore and ARM11 MPCore, the per-CPU watchdogs do appear to be the same
> and could use the same driver.
> 
> Any reason for creating a new driver rather than reusing the ARM11
> MPCore driver?
> 

Sorry Guys!!! Earlier I tried to find existing driver, but couldn't found one.
So sent a new one.

I went through this driver and found some shortcomings in it:
 - It looks it is not used by anyone now, as it required
   asm/hardware/arm_twd.h and it was removed in v2.6.31.
   So it would never compile.
 - It doesn't support clock framework, and works on fixed rate.
 - It works on fixed prescale value (256).
 - It doesn't support WDIOC_GETBOOTSTATUS.

So, please suggest how to proceed as my patch contains all these features.

regards,
viresh kumar.

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[srinidhi kasagar]

Viresh,

Recently I have sent two patches which are already queued in Russell's
tracker

6125/1      ARM TWD: move TWD registers to common header
6126/1      ARM mpcore_wdt: fix build failure and other fixes

which addresses the following:
1) fix build failure
2) movement of the MPCore TWD registers.

And currently, Ux500 machine uses this.

What I feel is to patch this existing driver if you think it is missing some
functionality.

regards,
Srinidhi



On Wed, May 19, 2010 at 9:32 AM, Viresh KUMAR <viresh.kumar@st.com> wrote:

> On 5/18/2010 6:50 PM, George G. Davis wrote:
> > Hi,
> >
> > On Tue, May 18, 2010 at 02:55:21PM +0530, srinidhi kasagar wrote:
> >> I do not understand why a new driver is required while having similar
> one
> >> for MPCore watchdog.
> >> Please have a look at drivers/watchdog/mpcore_wdt.c
> >
> > The same thought occurred to me.  Based on a cursory glance at the
> Cortex-A9
> > MPCore and ARM11 MPCore, the per-CPU watchdogs do appear to be the same
> > and could use the same driver.
> >
> > Any reason for creating a new driver rather than reusing the ARM11
> > MPCore driver?
> >
>
> Sorry Guys!!! Earlier I tried to find existing driver, but couldn't found
> one.
> So sent a new one.
>
> I went through this driver and found some shortcomings in it:
>  - It looks it is not used by anyone now, as it required
>   asm/hardware/arm_twd.h and it was removed in v2.6.31.
>   So it would never compile.
>  - It doesn't support clock framework, and works on fixed rate.
>  - It works on fixed prescale value (256).
>  - It doesn't support WDIOC_GETBOOTSTATUS.
>
> So, please suggest how to proceed as my patch contains all these features.
>
> regards,
> viresh kumar.
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20100519/0438244b/attachment.htm>

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Shilimkar, Santosh]

> -----Original Message-----
> From: linux-arm-kernel-bounces at lists.infradead.org [mailto:linux-arm-kernel-
> bounces at lists.infradead.org] On Behalf Of Viresh KUMAR
> Sent: Wednesday, May 19, 2010 9:33 AM
> To: George G. Davis; srinidhi kasagar; alan at lxorguk.ukuu.org.uk
> Cc: armando.visconti at st.com; shiraz.hashim at st.com; Jassi Brar; linus.walleij at stericsson.com; linux-
> arm-kernel at lists.infradead.org
> Subject: Re: [PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9
> 
> On 5/18/2010 6:50 PM, George G. Davis wrote:
> > Hi,
> >
> > On Tue, May 18, 2010 at 02:55:21PM +0530, srinidhi kasagar wrote:
> >> I do not understand why a new driver is required while having similar one
> >> for MPCore watchdog.
> >> Please have a look at drivers/watchdog/mpcore_wdt.c
> >
> > The same thought occurred to me.  Based on a cursory glance at the Cortex-A9
> > MPCore and ARM11 MPCore, the per-CPU watchdogs do appear to be the same
> > and could use the same driver.
> >
> > Any reason for creating a new driver rather than reusing the ARM11
> > MPCore driver?
> >
> 
> Sorry Guys!!! Earlier I tried to find existing driver, but couldn't found one.
> So sent a new one.
> 
> I went through this driver and found some shortcomings in it:
>  - It looks it is not used by anyone now, as it required
>    asm/hardware/arm_twd.h and it was removed in v2.6.31.
>    So it would never compile.
>  - It doesn't support clock framework, and works on fixed rate.
>  - It works on fixed prescale value (256).
>  - It doesn't support WDIOC_GETBOOTSTATUS.
> 
> So, please suggest how to proceed as my patch contains all these features.
> 
Can the existing driver be upgraded with all above missing pieces?

Regards,
Santosh

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

On 5/19/2010 10:47 AM, srinidhi kasagar wrote:
> Viresh,
> 
> Recently I have sent two patches which are already queued in Russell's
> tracker
> 
> 6125/1      ARM TWD: move TWD registers to common header
> 6126/1      ARM mpcore_wdt: fix build failure and other fixes
> 
> which addresses the following:
> 1) fix build failure
> 2) movement of the MPCore TWD registers.
> 
> And currently, Ux500 machine uses this.
> 
> What I feel is to patch this existing driver if you think it is missing some
> functionality.
> 

Thanks srinidhi, for this info.
We can use existing driver as well. Will send patch with enhancements if required.

viresh.

[PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9

[Viresh KUMAR]

On 5/19/2010 11:02 AM, Shilimkar, Santosh wrote:
>> -----Original Message-----
>> From: linux-arm-kernel-bounces at lists.infradead.org [mailto:linux-arm-kernel-
>> bounces at lists.infradead.org] On Behalf Of Viresh KUMAR
>> Sent: Wednesday, May 19, 2010 9:33 AM
>> To: George G. Davis; srinidhi kasagar; alan at lxorguk.ukuu.org.uk
>> Cc: armando.visconti at st.com; shiraz.hashim at st.com; Jassi Brar; linus.walleij at stericsson.com; linux-
>> arm-kernel at lists.infradead.org
>> Subject: Re: [PATCH] Watchdog: Adding support for Watchdog found with ARM CortexA9
>>
>> On 5/18/2010 6:50 PM, George G. Davis wrote:
>>> Hi,
>>>
>>> On Tue, May 18, 2010 at 02:55:21PM +0530, srinidhi kasagar wrote:
>>>> I do not understand why a new driver is required while having similar one
>>>> for MPCore watchdog.
>>>> Please have a look at drivers/watchdog/mpcore_wdt.c
>>>
>>> The same thought occurred to me.  Based on a cursory glance at the Cortex-A9
>>> MPCore and ARM11 MPCore, the per-CPU watchdogs do appear to be the same
>>> and could use the same driver.
>>>
>>> Any reason for creating a new driver rather than reusing the ARM11
>>> MPCore driver?
>>>
>>
>> Sorry Guys!!! Earlier I tried to find existing driver, but couldn't found one.
>> So sent a new one.
>>
>> I went through this driver and found some shortcomings in it:
>>  - It looks it is not used by anyone now, as it required
>>    asm/hardware/arm_twd.h and it was removed in v2.6.31.
>>    So it would never compile.
>>  - It doesn't support clock framework, and works on fixed rate.
>>  - It works on fixed prescale value (256).
>>  - It doesn't support WDIOC_GETBOOTSTATUS.
>>
>> So, please suggest how to proceed as my patch contains all these features.
>>
> Can the existing driver be upgraded with all above missing pieces?
> 

yes. will be done.

mpcore_wdt A9 questions

[John Linn]

Hi,

The A9 has a watchdog timer per CPU, but I don't see a way to use more
than one watchdog timer (one for each CPU) using the mpcore_wdt driver.

I tried to do my research but maybe I missed something. Is this a
limitation of watchdog timers in Linux or just this driver?

Thanks,
John



This email and any attachments are intended for the sole use of the named recipient(s) and contain(s) confidential information that may be proprietary, privileged or copyrighted under applicable law. If you are not the intended recipient, do not read, copy, or forward this email message or any attachments. Delete this email message and any attachments immediately.

mpcore_wdt A9 questions

[George G. Davis]

Hello John,

On Wed, Sep 22, 2010 at 09:36:52AM -0600, John Linn wrote:
> Hi,
> 
> The A9 has a watchdog timer per CPU, but I don't see a way to use more
> than one watchdog timer (one for each CPU) using the mpcore_wdt driver.
> 
> I tried to do my research but maybe I missed something. Is this a
> limitation of watchdog timers in Linux or just this driver?

It's not strictly a limitation in the watchdog subsystem, I suspect
it just not something that anyone has needed thus far.  Anyway,
here's something I was working on for upstream which adds support
for all MPCore watchdog timers.  N.B. This is based on v2.6.34 give or
take, not sure if it applies to current.  It still has issues with
per-cpu interrupts but interrupts aren't currently used, so...