On Sun, Jul 15, 2012 at 13:14:04, Zumeng Chen wrote:
> This patch implements the current watchdog framework for OMAP WDTimer,
> which factored out the common components, so the driver can just focus
> on the hardware related parts.
>
> Signed-off-by: Zumeng Chen <zumeng.chen@xxxxxxxxxxxxx>
> ---
> drivers/watchdog/omap_wdt.c | 342 ++++++++++++++++---------------------------
> drivers/watchdog/omap_wdt.h | 5 +
> 2 files changed, 128 insertions(+), 219 deletions(-)
>
> diff --git a/drivers/watchdog/omap_wdt.c b/drivers/watchdog/omap_wdt.c
> index 8285d65..cc5bc3e 100644
> --- a/drivers/watchdog/omap_wdt.c
> +++ b/drivers/watchdog/omap_wdt.c
> @@ -24,6 +24,9 @@
> *
> * Copyright (c) 2005 David Brownell
> * Use the driver model and standard identifiers; handle bigger timeouts.
> + *
> + * Copyright (c) 2012 WindRiver
> + * Changes cater for the current watchdog framework.
> */
>
> #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> @@ -33,7 +36,6 @@
> #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>
> @@ -50,8 +52,6 @@
>
> #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)");
> @@ -59,32 +59,14 @@ 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 {
> +struct omap_wdt_drvdata {
> + struct watchdog_device wdt;
> void __iomem *base; /* physical */
> struct device *dev;
> - int omap_wdt_users;
> struct resource *mem;
> - struct miscdevice omap_wdt_miscdev;
> };
>
> -static void omap_wdt_ping(struct omap_wdt_dev *wdev)
> -{
> - void __iomem *base = wdev->base;
> -
> - /* wait for posted write to complete */
> - 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));
> -
> - /* wait for posted write to complete */
> - while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> - cpu_relax();
> - /* reloaded WCRR from WLDR */
> -}
> -
> -static void omap_wdt_enable(struct omap_wdt_dev *wdev)
> +static void omap_wdt_enable(struct omap_wdt_drvdata *wdev)
> {
> void __iomem *base = wdev->base;
>
> @@ -98,7 +80,7 @@ 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_drvdata *wdev)
> {
> void __iomem *base = wdev->base;
>
> @@ -121,12 +103,19 @@ static void omap_wdt_adjust_timeout(unsigned new_timeout)
> timer_margin = new_timeout;
> }
>
> -static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
> +static int omap_wdt_set_timeout(struct watchdog_device *wdt_dev,
> + unsigned int new_timeout)
> {
> - u32 pre_margin = GET_WLDR_VAL(timer_margin);
> - void __iomem *base = wdev->base;
> + u32 pre_margin;
> + struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> + void __iomem *base = omap_wdev->base;
>
> - pm_runtime_get_sync(wdev->dev);
> + pm_runtime_get_sync(omap_wdev->dev);
> + omap_wdt_disable(omap_wdev);
> +
> + /* adjust timeout based on the new timeout */
> + omap_wdt_adjust_timeout(new_timeout);
> + pre_margin = GET_WLDR_VAL(timer_margin);
>
> /* just count up at 32 KHz */
> while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
> @@ -136,147 +125,88 @@ static void omap_wdt_set_timeout(struct omap_wdt_dev *wdev)
> while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x04)
> cpu_relax();
>
> - pm_runtime_put_sync(wdev->dev);
> + omap_wdt_enable(omap_wdev);
> + wdt_dev->timeout = new_timeout;
> + pm_runtime_put_sync(omap_wdev->dev);
> + return 0;
> }
>
> -/*
> - * Allow only one task to hold it open
> - */
> -static int omap_wdt_open(struct inode *inode, struct file *file)
> +static int omap_wdt_ping(struct watchdog_device *wdt_dev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(omap_wdt_dev);
> - void __iomem *base = wdev->base;
> -
> - if (test_and_set_bit(1, (unsigned long *)&(wdev->omap_wdt_users)))
> - return -EBUSY;
> -
> - pm_runtime_get_sync(wdev->dev);
> + struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> + void __iomem *base = omap_wdev->base;
>
> - /* initialize prescaler */
> - while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> - cpu_relax();
> + pm_runtime_get_sync(omap_wdev->dev);
> + spin_lock(&wdt_lock);
>
> - __raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
> - while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> + /* wait for posted write to complete */
> + while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> cpu_relax();
>
> - file->private_data = (void *) wdev;
> + wdt_trgr_pattern = ~wdt_trgr_pattern;
> + __raw_writel(wdt_trgr_pattern, (base + OMAP_WATCHDOG_TGR));
>
> - omap_wdt_set_timeout(wdev);
> - omap_wdt_ping(wdev); /* trigger loading of new timeout value */
> - omap_wdt_enable(wdev);
> + /* wait for posted write to complete */
> + /* reloaded WCRR from WLDR */
> + while ((__raw_readl(base + OMAP_WATCHDOG_WPS)) & 0x08)
> + cpu_relax();
>
> - pm_runtime_put_sync(wdev->dev);
> + spin_unlock(&wdt_lock);
> + pm_runtime_put_sync(omap_wdev->dev);
>
> - return nonseekable_open(inode, file);
> + return 0;
> }
>
> -static int omap_wdt_release(struct inode *inode, struct file *file)
> +static int omap_wdt_start(struct watchdog_device *wdt_dev)
> {
> - struct omap_wdt_dev *wdev = file->private_data;
> + struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
> + void __iomem *base = omap_wdev->base;
>
> - /*
> - * Shut off the timer unless NOWAYOUT is defined.
> - */
> -#ifndef CONFIG_WATCHDOG_NOWAYOUT
> - pm_runtime_get_sync(wdev->dev);
> + pm_runtime_get_sync(omap_wdev->dev);
> + /* initialize prescaler */
> + while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> + cpu_relax();
>
> - omap_wdt_disable(wdev);
> + __raw_writel((1 << 5) | (PTV << 2), base + OMAP_WATCHDOG_CNTRL);
> + while (__raw_readl(base + OMAP_WATCHDOG_WPS) & 0x01)
> + cpu_relax();
>
> - pm_runtime_put_sync(wdev->dev);
> -#else
> - pr_crit("Unexpected close, not stopping!\n");
> -#endif
> - wdev->omap_wdt_users = 0;
> + omap_wdt_set_timeout(&omap_wdev->wdt, timer_margin);
> + pm_runtime_put_sync(omap_wdev->dev);
>
> 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_stop(struct watchdog_device *wdt_dev)
> {
> - struct omap_wdt_dev *wdev = file->private_data;
> -
> - /* Refresh LOAD_TIME. */
> - if (len) {
> - pm_runtime_get_sync(wdev->dev);
> - spin_lock(&wdt_lock);
> - omap_wdt_ping(wdev);
> - spin_unlock(&wdt_lock);
> - pm_runtime_put_sync(wdev->dev);
> - }
> - return len;
> -}
> + struct omap_wdt_drvdata *omap_wdev = watchdog_get_drvdata(wdt_dev);
>
> -static long omap_wdt_ioctl(struct file *file, unsigned int cmd,
> - unsigned long arg)
> -{
> - 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:
> - pm_runtime_get_sync(wdev->dev);
> - spin_lock(&wdt_lock);
> - omap_wdt_ping(wdev);
> - spin_unlock(&wdt_lock);
> - pm_runtime_put_sync(wdev->dev);
> - return 0;
> - case WDIOC_SETTIMEOUT:
> - if (get_user(new_margin, (int __user *)arg))
> - return -EFAULT;
> - omap_wdt_adjust_timeout(new_margin);
> -
> - pm_runtime_get_sync(wdev->dev);
> - 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);
> - pm_runtime_put_sync(wdev->dev);
> - /* Fall */
> - case WDIOC_GETTIMEOUT:
> - return put_user(timer_margin, (int __user *)arg);
> - default:
> - return -ENOTTY;
> - }
> + pm_runtime_get_sync(omap_wdev->dev);
> + omap_wdt_disable(omap_wdev);
> + pm_runtime_put_sync(omap_wdev->dev);
> +
> + return 0;
> }
>
> -static const struct file_operations omap_wdt_fops = {
> +static const struct watchdog_ops omap_wdt_ops = {
> .owner = THIS_MODULE,
> - .write = omap_wdt_write,
> - .unlocked_ioctl = omap_wdt_ioctl,
> - .open = omap_wdt_open,
> - .release = omap_wdt_release,
> - .llseek = no_llseek,
> + .start = omap_wdt_start,
> + .stop = omap_wdt_stop,
> + .ping = omap_wdt_ping,
> + .set_timeout = omap_wdt_set_timeout,
> +};
> +
> +static const struct watchdog_info omap_wdt_info = {
> + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING |
> + WDIOF_CARDRESET,
> + .identity = "Omap Watchdog",
> };
>
> static int __devinit omap_wdt_probe(struct platform_device *pdev)
> {
> + struct omap_wdt_drvdata *omap_drvdata;
> + struct watchdog_device *omap_wdev;
> struct resource *res, *mem;
> - struct omap_wdt_dev *wdev;
> int ret;
>
> /* reserve static register mappings */
> @@ -286,68 +216,62 @@ 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;
> goto err_busy;
> }
>
> - wdev = kzalloc(sizeof(struct omap_wdt_dev), GFP_KERNEL);
> - if (!wdev) {
> + omap_drvdata = devm_kzalloc(&pdev->dev, sizeof(struct omap_wdt_drvdata),
> + GFP_KERNEL);
> + if (!omap_drvdata) {
> + dev_err(&pdev->dev, "Unable to allocate watchdog device\n");
> ret = -ENOMEM;
> goto err_kzalloc;
> }
>
> - wdev->omap_wdt_users = 0;
> - wdev->mem = mem;
> - wdev->dev = &pdev->dev;
> + omap_drvdata->dev = &pdev->dev;
> + omap_wdev = &omap_drvdata->wdt;
> + omap_wdev->info = &omap_wdt_info;
> + omap_wdev->ops = &omap_wdt_ops;
> + omap_wdev->timeout = TIMER_MARGIN_DEFAULT;
> + omap_wdev->min_timeout = 1;
> + omap_wdev->max_timeout = TIMER_MARGIN_MAX;
> +#ifdef CONFIG_WATCHDOG_NOWAYOUT
> + watchdog_set_nowayout(omap_wdev, true);
> +#endif
> + watchdog_set_drvdata(omap_wdev, omap_drvdata);
>
> - wdev->base = ioremap(res->start, resource_size(res));
> - if (!wdev->base) {
> + omap_drvdata->base = ioremap(res->start, resource_size(res));
> + if (!omap_drvdata->base) {
> ret = -ENOMEM;
> - goto err_ioremap;
> + goto err_kzalloc;
> }
>
> - platform_set_drvdata(pdev, wdev);
> -
> - pm_runtime_enable(wdev->dev);
> - pm_runtime_get_sync(wdev->dev);
> -
> - omap_wdt_disable(wdev);
> - omap_wdt_adjust_timeout(timer_margin);
> -
> - 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));
> - 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);
> -
> - pm_runtime_put_sync(wdev->dev);
> -
> - omap_wdt_dev = pdev;
> + ret = watchdog_register_device(&omap_drvdata->wdt);
> + if (ret < 0)
> + goto err_register_wd;
> +
> + pm_runtime_enable(&pdev->dev);
> + pm_runtime_get_sync(&pdev->dev);
> + omap_wdt_disable(omap_drvdata);
> + pm_runtime_put_sync(&pdev->dev);
> + platform_set_drvdata(pdev, omap_drvdata);
> +
> + /* For omap16xx we just keep it original as-is */
> + if (cpu_is_omap16xx())
> + omap_wdev->bootstatus = __raw_readw(ARM_SYSST);
> + else
> + omap_wdev->bootstatus = (omap_prcm_get_reset_sources() & 0x10)
> + >> OMAP3_PRM_RSTST_WD_BIT;
CPU check is really not receommended in driver, you should avoid this.
I understand that, driver was already doing this, but can this be handled by
IP rev? if not, you may want to use pdata for this.
Also I understand that, this is tied to prcm code base as far as omap2 is concerned. May be Tony or others can comment on this.
Thanks,
Vaibhav
> + pr_info("OMAP WDTimer Rev 0x%02x: Initial timeout %dsec status= 0x%x\n",
> + __raw_readl(omap_drvdata->base + OMAP_WATCHDOG_REV)
> + & 0xFF, timer_margin, omap_wdev->bootstatus);
>
> return 0;
>
> -err_misc:
> - pm_runtime_disable(wdev->dev);
> - platform_set_drvdata(pdev, NULL);
> - iounmap(wdev->base);
> -
> -err_ioremap:
> - wdev->base = NULL;
> - kfree(wdev);
> +err_register_wd:
> + iounmap(omap_drvdata->base);
>
> err_kzalloc:
> release_mem_region(res->start, resource_size(res));
> @@ -358,34 +282,17 @@ err_get_resource:
> return ret;
> }
>
> -static void omap_wdt_shutdown(struct platform_device *pdev)
> -{
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> -
> - if (wdev->omap_wdt_users) {
> - pm_runtime_get_sync(wdev->dev);
> - omap_wdt_disable(wdev);
> - pm_runtime_put_sync(wdev->dev);
> - }
> -}
> -
> static int __devexit omap_wdt_remove(struct platform_device *pdev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> + struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
> struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>
> - pm_runtime_disable(wdev->dev);
> - if (!res)
> - return -ENOENT;
> + pm_runtime_disable(&pdev->dev);
>
> - misc_deregister(&(wdev->omap_wdt_miscdev));
> release_mem_region(res->start, resource_size(res));
> platform_set_drvdata(pdev, NULL);
>
> - iounmap(wdev->base);
> -
> - kfree(wdev);
> - omap_wdt_dev = NULL;
> + iounmap(omap_wdev->base);
>
> return 0;
> }
> @@ -400,12 +307,12 @@ 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 omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
>
> - if (wdev->omap_wdt_users) {
> - pm_runtime_get_sync(wdev->dev);
> - omap_wdt_disable(wdev);
> - pm_runtime_put_sync(wdev->dev);
> + if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
> + pm_runtime_get_sync(&pdev->dev);
> + omap_wdt_disable(omap_wdev);
> + pm_runtime_put_sync(&pdev->dev);
> }
>
> return 0;
> @@ -413,13 +320,12 @@ static int omap_wdt_suspend(struct platform_device *pdev, pm_message_t state)
>
> static int omap_wdt_resume(struct platform_device *pdev)
> {
> - struct omap_wdt_dev *wdev = platform_get_drvdata(pdev);
> -
> - if (wdev->omap_wdt_users) {
> - pm_runtime_get_sync(wdev->dev);
> - omap_wdt_enable(wdev);
> - omap_wdt_ping(wdev);
> - pm_runtime_put_sync(wdev->dev);
> + struct omap_wdt_drvdata *omap_wdev = platform_get_drvdata(pdev);
> + if (test_bit(WDOG_DEV_OPEN, &omap_wdev->wdt.status)) {
> + pm_runtime_get_sync(&pdev->dev);
> + omap_wdt_enable(omap_wdev);
> + omap_wdt_ping(&omap_wdev->wdt);
> + pm_runtime_put_sync(&pdev->dev);
> }
>
> return 0;
> @@ -433,7 +339,6 @@ static int omap_wdt_resume(struct platform_device *pdev)
> static struct platform_driver omap_wdt_driver = {
> .probe = omap_wdt_probe,
> .remove = __devexit_p(omap_wdt_remove),
> - .shutdown = omap_wdt_shutdown,
> .suspend = omap_wdt_suspend,
> .resume = omap_wdt_resume,
> .driver = {
> @@ -446,5 +351,4 @@ module_platform_driver(omap_wdt_driver);
>
> MODULE_AUTHOR("George G. Davis");
> MODULE_LICENSE("GPL");
> -MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
> MODULE_ALIAS("platform:omap_wdt");
> diff --git a/drivers/watchdog/omap_wdt.h b/drivers/watchdog/omap_wdt.h
> index 09b774c..cf5f037 100644
> --- a/drivers/watchdog/omap_wdt.h
> +++ b/drivers/watchdog/omap_wdt.h
> @@ -51,4 +51,9 @@
> #define PTV 0 /* prescale */
> #define GET_WLDR_VAL(secs) (0xffffffff - ((secs) * (32768/(1<<PTV))) + 1)
>
> +/* MPU_WD_RST bit in PRM_RSTST show Omap WDTimer reset event.
> + * 0x0 = 0x0 : No watchdog reset.
> + * 0x1 = 0x1 : watchdog reset has occurred. */
> +#define OMAP3_PRM_RSTST_WD_BIT 4
> +
> #endif /* _OMAP_WATCHDOG_H */
> --
> 1.7.5.4
>
>
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