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Date: Mon, 10 Sep 2012 15:02:47 +0530
From: "Vutla, Lokesh" <lokeshvutla@...com>
To: Aaro Koskinen <aaro.koskinen@....fi>
Cc: linux-watchdog@...r.kernel.org, linux-omap@...r.kernel.org,
linux-kernel@...r.kernel.org, jarkko.nikula@...mer.com
Subject: Re: [PATCH v2] watchdog: omap_wdt: convert to new watchdog core
On Sat, Sep 8, 2012 at 11:34 PM, Aaro Koskinen <aaro.koskinen@....fi> wrote:
> Convert omap_wdt to new watchdog core. On OMAP boards, there are usually
> multiple watchdogs. Since the new watchdog core supports multiple
> watchdogs, all watchdog drivers used on OMAP should be converted.
>
> The legacy watchdog device node is still created, so this should not
> break existing users.
>
> Signed-off-by: Aaro Koskinen <aaro.koskinen@....fi>
> ---
>
> v2: Fix a bug in the first version of the patch: __omap_wdt_disable()
> in probe was mistakenly moved outside PM runtime calls. This caused a
> crash as device was probably accessed with some clocks off. Thanks to
> Jarkko Nikula <jarkko.nikula@...mer.com> for reporting this.
Tested with various watchdog testcases. Seems to work fine.
Tested-by: Lokesh Vutla <lokeshvutla@...com>
>
> drivers/watchdog/Kconfig | 1 +
> drivers/watchdog/omap_wdt.c | 266 ++++++++++++++++++-------------------------
> 2 files changed, 114 insertions(+), 153 deletions(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 0526c7a..212b566 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -232,6 +232,7 @@ config EP93XX_WATCHDOG
> config OMAP_WATCHDOG
> tristate "OMAP Watchdog"
> depends on ARCH_OMAP16XX || ARCH_OMAP2PLUS
> + select WATCHDOG_CORE
> help
> Support for TI OMAP1610/OMAP1710/OMAP2420/OMAP3430/OMAP4430 watchdog. Say 'Y'
> here to enable the OMAP1610/OMAP1710/OMAP2420/OMAP3430/OMAP4430 watchdog timer.
> diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
> index fceec4f..1636f2c 100644
> --- a/drivers/watchdog/omap_wdt.c
> +++ b/drivers/watchdog/omap_wdt.c
> @@ -31,18 +31,14 @@
> #include <linux/module.h>
> #include <linux/types.h>
> #include <linux/kernel.h>
> -#include <linux/fs.h>
> #include <linux/mm.h>
> -#include <linux/miscdevice.h>
> #include <linux/watchdog.h>
> #include <linux/reboot.h>
> #include <linux/init.h>
> #include <linux/err.h>
> #include <linux/platform_device.h>
> #include <linux/moduleparam.h>
> -#include <linux/bitops.h>
> #include <linux/io.h>
> -#include <linux/uaccess.h>
> #include <linux/slab.h>
> #include <linux/pm_runtime.h>
> #include <mach/hardware.h>
> @@ -50,24 +46,20 @@
>
> #include "omap_wdt.h"
>
> -static struct platform_device *omap_wdt_dev;
> -
> static unsigned timer_margin;
> module_param(timer_margin, uint, 0);
> MODULE_PARM_DESC(timer_margin, "initial watchdog timeout (in seconds)");
>
> -static unsigned int wdt_trgr_pattern = 0x1234;
> -static DEFINE_SPINLOCK(wdt_lock);
> -
> struct omap_wdt_dev {
> void __iomem *base; /* physical */
> struct device *dev;
> - int omap_wdt_users;
> + bool omap_wdt_users;
> struct resource *mem;
> - struct miscdevice omap_wdt_miscdev;
> + int wdt_trgr_pattern;
> + struct mutex lock; /* to avoid races with PM */
> };
>
> -static void omap_wdt_ping(struct omap_wdt_dev *wdev)
> +static void __omap_wdt_ping(struct omap_wdt_dev *wdev)
> {
> void __iomem *base = wdev->base;
>
> @@ -75,8 +67,8 @@ static void omap_wdt_ping(struct omap_wdt_dev *wdev)
> while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> cpu_relax();
>
> - wdt_trgr_pattern = ~wdt_trgr_pattern;
> - __raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
> + wdev->wdt_trgr_pattern = ~wdev->wdt_trgr_pattern;
> + __raw_writel(wdev->wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
>
> /* wait for posted write to complete */
> while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> @@ -84,7 +76,7 @@ static void omap_wdt_ping(struct omap_wdt_dev *wdev)
> /* reloaded WCRR from WLDR */
> }
>
> -static void omap_wdt_enable(struct omap_wdt_dev *wdev)
> +static void __omap_wdt_enable(struct omap_wdt_dev *wdev)
> {
> void __iomem *base = wdev->base;
>
> @@ -98,7 +90,7 @@ static void omap_wdt_enable(struct omap_wdt_dev *wdev)
> cpu_relax();
> }
>
> -static void omap_wdt_disable(struct omap_wdt_dev *wdev)
> +static void __omap_wdt_disable(struct omap_wdt_dev *wdev)
> {
> void __iomem *base = wdev->base;
>
> @@ -112,18 +104,10 @@ static void omap_wdt_disable(struct omap_wdt_dev *wdev)
> cpu_relax();
> }
>
> -static void omap_wdt_adjust_timeout(unsigned new_timeout)
> -{
> - if (new_timeout < TIMER_MARGIN_MIN)
> - new_timeout = TIMER_MARGIN_DEFAULT;
> - if (new_timeout > TIMER_MARGIN_MAX)
> - new_timeout = TIMER_MARGIN_MAX;
> - timer_margin = new_timeout;
> -}
> -
> -static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
> +static void __omap_wdt_set_timeout(struct omap_wdt_dev *wdev,
> + unsigned int timeout)
> {
> - u32 pre_margin = GET_WLDR_VAL(timer_margin);
> + u32 pre_margin = GET_WLDR_VAL(timeout);
> void __iomem *base = wdev->base;
>
> /* just count up at 32 KHz */
> @@ -135,16 +119,14 @@ static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
> cpu_relax();
> }
>
> -/*
> - * Allow only one task to hold it open
> - */
> -static int omap_wdt_open(struct inode *inode, struct file *file)
> +static int omap_wdt_start(struct watchdog_device *wdog)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> void __iomem *base = wdev->base;
>
> - if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
> - return -EBUSY;
> + mutex_lock(&wdev->lock);
> +
> + wdev->omap_wdt_users = true;
>
> pm_runtime_get_sync(wdev->dev);
>
> @@ -156,115 +138,79 @@ static int omap_wdt_open(struct inode *inode, struct file *file)
> while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> cpu_relax();
>
> - file->private_data = (void *) wdev;
> + __omap_wdt_set_timeout(wdev, wdog->timeout);
> + __omap_wdt_ping(wdev); /* trigger loading of new timeout value */
> + __omap_wdt_enable(wdev);
>
> - omap_wdt_set_timeout(wdev);
> - omap_wdt_ping(wdev); /* trigger loading of new timeout value */
> - omap_wdt_enable(wdev);
> + mutex_unlock(&wdev->lock);
>
> - return nonseekable_open(inode, file);
> + return 0;
> }
>
> -static int omap_wdt_release(struct inode *inode, struct file *file)
> +static int omap_wdt_stop(struct watchdog_device *wdog)
> {
> - struct omap_wdt_dev *wdev = file->private_data;
> -
> - /*
> - * Shut off the timer unless NOWAYOUT is defined.
> - */
> -#ifndef CONFIG_WATCHDOG_NOWAYOUT
> - omap_wdt_disable(wdev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
>
> + mutex_lock(&wdev->lock);
> + __omap_wdt_disable(wdev);
> pm_runtime_put_sync(wdev->dev);
> -#else
> - pr_crit("Unexpected close, not stopping!\n");
> -#endif
> - wdev->omap_wdt_users = 0;
> -
> + wdev->omap_wdt_users = false;
> + mutex_unlock(&wdev->lock);
> return 0;
> }
>
> -static ssize_t omap_wdt_write(struct file *file, const char __user *data,
> - size_t len, loff_t *ppos)
> +static int omap_wdt_ping(struct watchdog_device *wdog)
> {
> - struct omap_wdt_dev *wdev = file->private_data;
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
>
> - /* Refresh LOAD_TIME. */
> - if (len) {
> - spin_lock(&wdt_lock);
> - omap_wdt_ping(wdev);
> - spin_unlock(&wdt_lock);
> - }
> - return len;
> + mutex_lock(&wdev->lock);
> + __omap_wdt_ping(wdev);
> + mutex_unlock(&wdev->lock);
> +
> + return 0;
> }
>
> -static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> - unsigned long arg)
> +static int omap_wdt_set_timeout(struct watchdog_device *wdog,
> + unsigned int timeout)
> {
> - struct omap_wdt_dev *wdev;
> - int new_margin;
> - static const struct watchdog_info ident = {
> - .identity = "OMAP Watchdog",
> - .options = WDIOF_SETTIMEOUT,
> - .firmware_version = 0,
> - };
> -
> - wdev = file->private_data;
> -
> - switch (cmd) {
> - case WDIOC_GETSUPPORT:
> - return copy_to_user((struct watchdog_info __user *)arg, &ident,
> - sizeof(ident));
> - case WDIOC_GETSTATUS:
> - return put_user(0, (int __user *)arg);
> - case WDIOC_GETBOOTSTATUS:
> - if (cpu_is_omap16xx())
> - return put_user(__raw_readw(ARM_SYSST),
> - (int __user *)arg);
> - if (cpu_is_omap24xx())
> - return put_user(omap_prcm_get_reset_sources(),
> - (int __user *)arg);
> - return put_user(0, (int __user *)arg);
> - case WDIOC_KEEPALIVE:
> - spin_lock(&wdt_lock);
> - omap_wdt_ping(wdev);
> - spin_unlock(&wdt_lock);
> - return 0;
> - case WDIOC_SETTIMEOUT:
> - if (get_user(new_margin, (int __user *)arg))
> - return -EFAULT;
> - omap_wdt_adjust_timeout(new_margin);
> -
> - spin_lock(&wdt_lock);
> - omap_wdt_disable(wdev);
> - omap_wdt_set_timeout(wdev);
> - omap_wdt_enable(wdev);
> -
> - omap_wdt_ping(wdev);
> - spin_unlock(&wdt_lock);
> - /* Fall */
> - case WDIOC_GETTIMEOUT:
> - return put_user(timer_margin, (int __user *)arg);
> - default:
> - return -ENOTTY;
> - }
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> +
> + mutex_lock(&wdev->lock);
> + __omap_wdt_disable(wdev);
> + __omap_wdt_set_timeout(wdev, timeout);
> + __omap_wdt_enable(wdev);
> + __omap_wdt_ping(wdev);
> + wdog->timeout = timeout;
> + mutex_unlock(&wdev->lock);
> +
> + return 0;
> }
>
> -static const struct file_operations omap_wdt_fops = {
> - .owner = THIS_MODULE,
> - .write = omap_wdt_write,
> - .unlocked_ioctl = omap_wdt_ioctl,
> - .open = omap_wdt_open,
> - .release = omap_wdt_release,
> - .llseek = no_llseek,
> +static const struct watchdog_info omap_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
> + .identity = "OMAP Watchdog",
> +};
> +
> +static const struct watchdog_ops omap_wdt_ops = {
> + .owner = THIS_MODULE,
> + .start = omap_wdt_start,
> + .stop = omap_wdt_stop,
> + .ping = omap_wdt_ping,
> + .set_timeout = omap_wdt_set_timeout,
> };
>
> static int __devinit omap_wdt_probe(struct platform_device *pdev)
> {
> + bool nowayout = WATCHDOG_NOWAYOUT;
> + struct watchdog_device *omap_wdt;
> struct resource *res, *mem;
> struct omap_wdt_dev *wdev;
> int ret;
>
> + omap_wdt = kzalloc(sizeof(*omap_wdt), GFP_KERNEL);
> + if (!omap_wdt)
> + return -ENOMEM;
> +
> /* reserve static register mappings */
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> if (!res) {
> @@ -272,11 +218,6 @@ static int __devinit omap_wdt_probe(struct platform_device *pdev)
> goto err_get_resource;
> }
>
> - if (omap_wdt_dev) {
> - ret = -EBUSY;
> - goto err_busy;
> - }
> -
> mem = request_mem_region(res->start, resource_size(res), pdev->name);
> if (!mem) {
> ret = -EBUSY;
> @@ -289,9 +230,30 @@ static int __devinit omap_wdt_probe(struct platform_device *pdev)
> goto err_kzalloc;
> }
>
> - wdev->omap_wdt_users = 0;
> - wdev->mem = mem;
> - wdev->dev = &pdev->dev;
> + omap_wdt->info = &omap_wdt_info;
> + omap_wdt->ops = &omap_wdt_ops;
> + omap_wdt->min_timeout = TIMER_MARGIN_MIN;
> + omap_wdt->max_timeout = TIMER_MARGIN_MAX;
> +
> + if (timer_margin >= TIMER_MARGIN_MIN &&
> + timer_margin <= TIMER_MARGIN_MAX)
> + omap_wdt->timeout = timer_margin;
> + else
> + omap_wdt->timeout = TIMER_MARGIN_DEFAULT;
> +
> + if (cpu_is_omap16xx())
> + omap_wdt->bootstatus = __raw_readw(ARM_SYSST);
> + else if (cpu_is_omap24xx())
> + omap_wdt->bootstatus = omap_prcm_get_reset_sources();
> +
> + watchdog_set_drvdata(omap_wdt, wdev);
> + watchdog_set_nowayout(omap_wdt, nowayout);
> +
> + wdev->omap_wdt_users = false;
> + wdev->mem = mem;
> + wdev->dev = &pdev->dev;
> + wdev->wdt_trgr_pattern = 0x1234;
> + mutex_init(&wdev->lock);
>
> wdev->base = ioremap(res->start, resource_size(res));
> if (!wdev->base) {
> @@ -299,31 +261,23 @@ static int __devinit omap_wdt_probe(struct platform_device *pdev)
> goto err_ioremap;
> }
>
> - platform_set_drvdata(pdev, wdev);
> + platform_set_drvdata(pdev, omap_wdt);
>
> pm_runtime_enable(wdev->dev);
> pm_runtime_get_sync(wdev->dev);
>
> - omap_wdt_disable(wdev);
> - omap_wdt_adjust_timeout(timer_margin);
> + __omap_wdt_disable(wdev);
>
> - wdev->omap_wdt_miscdev.parent = &pdev->dev;
> - wdev->omap_wdt_miscdev.minor = WATCHDOG_MINOR;
> - wdev->omap_wdt_miscdev.name = "watchdog";
> - wdev->omap_wdt_miscdev.fops = &omap_wdt_fops;
> -
> - ret = misc_register(&(wdev->omap_wdt_miscdev));
> + ret = watchdog_register_device(omap_wdt);
> if (ret)
> goto err_misc;
>
> pr_info("OMAP Watchdog Timer Rev 0x%02x: initial timeout %d sec\n",
> __raw_readl(wdev->base + OMAP_WATCHDOG_REV) & 0xFF,
> - timer_margin);
> + omap_wdt->timeout);
>
> pm_runtime_put_sync(wdev->dev);
>
> - omap_wdt_dev = pdev;
> -
> return 0;
>
> err_misc:
> @@ -340,37 +294,38 @@ err_kzalloc:
>
> err_busy:
> err_get_resource:
> -
> + kfree(omap_wdt);
> return ret;
> }
>
> static void omap_wdt_shutdown(struct platform_device *pdev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
>
> + mutex_lock(&wdev->lock);
> if (wdev->omap_wdt_users) {
> - omap_wdt_disable(wdev);
> + __omap_wdt_disable(wdev);
> pm_runtime_put_sync(wdev->dev);
> }
> + mutex_unlock(&wdev->lock);
> }
>
> static int __devexit omap_wdt_remove(struct platform_device *pdev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
> struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>
> pm_runtime_disable(wdev->dev);
> - if (!res)
> - return -ENOENT;
> -
> - misc_deregister(&(wdev->omap_wdt_miscdev));
> + watchdog_unregister_device(wdog);
> release_mem_region(res->start, resource_size(res));
> platform_set_drvdata(pdev, NULL);
>
> iounmap(wdev->base);
>
> kfree(wdev);
> - omap_wdt_dev = NULL;
> + kfree(wdog);
>
> return 0;
> }
> @@ -385,25 +340,31 @@ static int __devexit omap_wdt_remove(struct platform_device *pdev)
>
> static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
>
> + mutex_lock(&wdev->lock);
> if (wdev->omap_wdt_users) {
> - omap_wdt_disable(wdev);
> + __omap_wdt_disable(wdev);
> pm_runtime_put_sync(wdev->dev);
> }
> + mutex_unlock(&wdev->lock);
>
> return 0;
> }
>
> static int omap_wdt_resume(struct platform_device *pdev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct omap_wdt_dev *wdev = watchdog_get_drvdata(wdog);
>
> + mutex_lock(&wdev->lock);
> if (wdev->omap_wdt_users) {
> pm_runtime_get_sync(wdev->dev);
> - omap_wdt_enable(wdev);
> - omap_wdt_ping(wdev);
> + __omap_wdt_enable(wdev);
> + __omap_wdt_ping(wdev);
> }
> + mutex_unlock(&wdev->lock);
>
> return 0;
> }
> @@ -436,5 +397,4 @@ module_platform_driver(omap_wdt_driver);
>
> MODULE_AUTHOR("George G. Davis");
> MODULE_LICENSE("GPL");
> -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
> MODULE_ALIAS("platform:omap_wdt");
> --
> 1.7.2.5
>
> --
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