[PATCH v2] watchdog: imx2_wdt: convert to watchdog core api
Anatolij Gustschin
agust at denx.de
Tue May 6 16:33:02 PDT 2014
On Fri, 11 Apr 2014 08:57:14 +0200
Anatolij Gustschin <agust at denx.de> wrote:
> Convert the imx2_wdt driver to the new watchdog core api.
>
> Signed-off-by: Anatolij Gustschin <agust at denx.de>
> Cc: Wolfram Sang <wsa at the-dreams.de>
> Cc: Wim Van Sebroeck <wim at iguana.be>
Ping. Will this patch be queued for next?
Thanks,
Anatolij
> ---
> NOTE: This patch applies on top of the imx2_wdt regmap-mmio support
> patch series http://comments.gmane.org/gmane.linux.kernel/1677735
>
> Changes since first version:
> - simplify return in imx2_wdt_is_running()
> - fix "WARNING: quoted string split across lines"
>
> drivers/watchdog/Kconfig | 1 +
> drivers/watchdog/imx2_wdt.c | 292 ++++++++++++++++++-------------------------
> 2 files changed, 123 insertions(+), 170 deletions(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index f2a15f4..5e78c77c 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -379,6 +379,7 @@ config IMX2_WDT
> tristate "IMX2+ Watchdog"
> depends on ARCH_MXC
> select REGMAP_MMIO
> + select WATCHDOG_CORE
> help
> This is the driver for the hardware watchdog
> on the Freescale IMX2 and later processors.
> diff --git a/drivers/watchdog/imx2_wdt.c b/drivers/watchdog/imx2_wdt.c
> index 76fa724..9d4874f 100644
> --- a/drivers/watchdog/imx2_wdt.c
> +++ b/drivers/watchdog/imx2_wdt.c
> @@ -22,18 +22,15 @@
> */
>
> #include <linux/clk.h>
> -#include <linux/fs.h>
> #include <linux/init.h>
> #include <linux/io.h>
> #include <linux/jiffies.h>
> #include <linux/kernel.h>
> -#include <linux/miscdevice.h>
> #include <linux/module.h>
> #include <linux/moduleparam.h>
> #include <linux/platform_device.h>
> #include <linux/regmap.h>
> #include <linux/timer.h>
> -#include <linux/uaccess.h>
> #include <linux/watchdog.h>
>
> #define DRIVER_NAME "imx2-wdt"
> @@ -56,19 +53,12 @@
>
> #define WDOG_SEC_TO_COUNT(s) ((s * 2 - 1) << 8)
>
> -#define IMX2_WDT_STATUS_OPEN 0
> -#define IMX2_WDT_STATUS_STARTED 1
> -#define IMX2_WDT_EXPECT_CLOSE 2
> -
> -static struct {
> +struct imx2_wdt_device {
> struct clk *clk;
> struct regmap *regmap;
> - unsigned timeout;
> - unsigned long status;
> struct timer_list timer; /* Pings the watchdog when closed */
> -} imx2_wdt;
> -
> -static struct miscdevice imx2_wdt_miscdev;
> + struct watchdog_device wdog;
> +};
>
> static bool nowayout = WATCHDOG_NOWAYOUT;
> module_param(nowayout, bool, 0);
> @@ -86,11 +76,12 @@ static const struct watchdog_info imx2_wdt_info = {
> .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
> };
>
> -static inline void imx2_wdt_setup(void)
> +static inline void imx2_wdt_setup(struct watchdog_device *wdog)
> {
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> u32 val;
>
> - regmap_read(imx2_wdt.regmap, IMX2_WDT_WCR, &val);
> + regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
>
> /* Suspend timer in low power mode, write once-only */
> val |= IMX2_WDT_WCR_WDZST;
> @@ -101,157 +92,93 @@ static inline void imx2_wdt_setup(void)
> /* Keep Watchdog Disabled */
> val &= ~IMX2_WDT_WCR_WDE;
> /* Set the watchdog's Time-Out value */
> - val |= WDOG_SEC_TO_COUNT(imx2_wdt.timeout);
> + val |= WDOG_SEC_TO_COUNT(wdog->timeout);
>
> - regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
> + regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
>
> /* enable the watchdog */
> val |= IMX2_WDT_WCR_WDE;
> - regmap_write(imx2_wdt.regmap, IMX2_WDT_WCR, val);
> + regmap_write(wdev->regmap, IMX2_WDT_WCR, val);
> }
>
> -static inline void imx2_wdt_ping(void)
> +static inline bool imx2_wdt_is_running(struct imx2_wdt_device *wdev)
> {
> - regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
> - regmap_write(imx2_wdt.regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
> -}
> + u32 val;
>
> -static void imx2_wdt_timer_ping(unsigned long arg)
> -{
> - /* ping it every imx2_wdt.timeout / 2 seconds to prevent reboot */
> - imx2_wdt_ping();
> - mod_timer(&imx2_wdt.timer, jiffies + imx2_wdt.timeout * HZ / 2);
> + regmap_read(wdev->regmap, IMX2_WDT_WCR, &val);
> +
> + return val & IMX2_WDT_WCR_WDE;
> }
>
> -static void imx2_wdt_start(void)
> +static int imx2_wdt_ping(struct watchdog_device *wdog)
> {
> - if (!test_and_set_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
> - /* at our first start we enable clock and do initialisations */
> - clk_prepare_enable(imx2_wdt.clk);
> -
> - imx2_wdt_setup();
> - } else /* delete the timer that pings the watchdog after close */
> - del_timer_sync(&imx2_wdt.timer);
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
>
> - /* Watchdog is enabled - time to reload the timeout value */
> - imx2_wdt_ping();
> + regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ1);
> + regmap_write(wdev->regmap, IMX2_WDT_WSR, IMX2_WDT_SEQ2);
> + return 0;
> }
>
> -static void imx2_wdt_stop(void)
> +static void imx2_wdt_timer_ping(unsigned long arg)
> {
> - /* we don't need a clk_disable, it cannot be disabled once started.
> - * We use a timer to ping the watchdog while /dev/watchdog is closed */
> - imx2_wdt_timer_ping(0);
> + struct watchdog_device *wdog = (struct watchdog_device *)arg;
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> +
> + /* ping it every wdog->timeout / 2 seconds to prevent reboot */
> + imx2_wdt_ping(wdog);
> + mod_timer(&wdev->timer, jiffies + wdog->timeout * HZ / 2);
> }
>
> -static void imx2_wdt_set_timeout(int new_timeout)
> +static int imx2_wdt_set_timeout(struct watchdog_device *wdog,
> + unsigned int new_timeout)
> {
> - regmap_update_bits(imx2_wdt.regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> +
> + regmap_update_bits(wdev->regmap, IMX2_WDT_WCR, IMX2_WDT_WCR_WT,
> WDOG_SEC_TO_COUNT(new_timeout));
> + return 0;
> }
>
> -static int imx2_wdt_open(struct inode *inode, struct file *file)
> +static int imx2_wdt_start(struct watchdog_device *wdog)
> {
> - if (test_and_set_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status))
> - return -EBUSY;
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
>
> - imx2_wdt_start();
> - return nonseekable_open(inode, file);
> + if (imx2_wdt_is_running(wdev)) {
> + /* delete the timer that pings the watchdog after close */
> + del_timer_sync(&wdev->timer);
> + imx2_wdt_set_timeout(wdog, wdog->timeout);
> + } else
> + imx2_wdt_setup(wdog);
> +
> + return imx2_wdt_ping(wdog);
> }
>
> -static int imx2_wdt_close(struct inode *inode, struct file *file)
> +static int imx2_wdt_stop(struct watchdog_device *wdog)
> {
> - if (test_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status) && !nowayout)
> - imx2_wdt_stop();
> - else {
> - dev_crit(imx2_wdt_miscdev.parent,
> - "Unexpected close: Expect reboot!\n");
> - imx2_wdt_ping();
> - }
> -
> - clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
> - clear_bit(IMX2_WDT_STATUS_OPEN, &imx2_wdt.status);
> + /*
> + * We don't need a clk_disable, it cannot be disabled once started.
> + * We use a timer to ping the watchdog while /dev/watchdog is closed
> + */
> + imx2_wdt_timer_ping((unsigned long)wdog);
> return 0;
> }
>
> -static long imx2_wdt_ioctl(struct file *file, unsigned int cmd,
> - unsigned long arg)
> +static inline void imx2_wdt_ping_if_active(struct watchdog_device *wdog)
> {
> - void __user *argp = (void __user *)arg;
> - int __user *p = argp;
> - int new_value;
> - u32 val;
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
>
> - switch (cmd) {
> - case WDIOC_GETSUPPORT:
> - return copy_to_user(argp, &imx2_wdt_info,
> - sizeof(struct watchdog_info)) ? -EFAULT : 0;
> -
> - case WDIOC_GETSTATUS:
> - return put_user(0, p);
> -
> - case WDIOC_GETBOOTSTATUS:
> - regmap_read(imx2_wdt.regmap, IMX2_WDT_WRSR, &val);
> - new_value = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
> - return put_user(new_value, p);
> -
> - case WDIOC_KEEPALIVE:
> - imx2_wdt_ping();
> - return 0;
> -
> - case WDIOC_SETTIMEOUT:
> - if (get_user(new_value, p))
> - return -EFAULT;
> - if ((new_value < 1) || (new_value > IMX2_WDT_MAX_TIME))
> - return -EINVAL;
> - imx2_wdt_set_timeout(new_value);
> - imx2_wdt.timeout = new_value;
> - imx2_wdt_ping();
> -
> - /* Fallthrough to return current value */
> - case WDIOC_GETTIMEOUT:
> - return put_user(imx2_wdt.timeout, p);
> -
> - default:
> - return -ENOTTY;
> + if (imx2_wdt_is_running(wdev)) {
> + imx2_wdt_set_timeout(wdog, wdog->timeout);
> + imx2_wdt_timer_ping((unsigned long)wdog);
> }
> }
>
> -static ssize_t imx2_wdt_write(struct file *file, const char __user *data,
> - size_t len, loff_t *ppos)
> -{
> - size_t i;
> - char c;
> -
> - if (len == 0) /* Can we see this even ? */
> - return 0;
> -
> - clear_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
> - /* scan to see whether or not we got the magic character */
> - for (i = 0; i != len; i++) {
> - if (get_user(c, data + i))
> - return -EFAULT;
> - if (c == 'V')
> - set_bit(IMX2_WDT_EXPECT_CLOSE, &imx2_wdt.status);
> - }
> -
> - imx2_wdt_ping();
> - return len;
> -}
> -
> -static const struct file_operations imx2_wdt_fops = {
> +static struct watchdog_ops imx2_wdt_ops = {
> .owner = THIS_MODULE,
> - .llseek = no_llseek,
> - .unlocked_ioctl = imx2_wdt_ioctl,
> - .open = imx2_wdt_open,
> - .release = imx2_wdt_close,
> - .write = imx2_wdt_write,
> -};
> -
> -static struct miscdevice imx2_wdt_miscdev = {
> - .minor = WATCHDOG_MINOR,
> - .name = "watchdog",
> - .fops = &imx2_wdt_fops,
> + .start = imx2_wdt_start,
> + .stop = imx2_wdt_stop,
> + .ping = imx2_wdt_ping,
> + .set_timeout = imx2_wdt_set_timeout,
> };
>
> static struct regmap_config imx2_wdt_regmap_config = {
> @@ -263,76 +190,101 @@ static struct regmap_config imx2_wdt_regmap_config = {
>
> static int __init imx2_wdt_probe(struct platform_device *pdev)
> {
> + struct imx2_wdt_device *wdev;
> + struct watchdog_device *wdog;
> struct resource *res;
> void __iomem *base;
> int ret;
> + u32 val;
> +
> + wdev = devm_kzalloc(&pdev->dev, sizeof(*wdev), GFP_KERNEL);
> + if (!wdev)
> + return -ENOMEM;
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> base = devm_ioremap_resource(&pdev->dev, res);
> if (IS_ERR(base))
> return PTR_ERR(base);
>
> - imx2_wdt.regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
> - &imx2_wdt_regmap_config);
> - if (IS_ERR(imx2_wdt.regmap)) {
> + wdev->regmap = devm_regmap_init_mmio_clk(&pdev->dev, NULL, base,
> + &imx2_wdt_regmap_config);
> + if (IS_ERR(wdev->regmap)) {
> dev_err(&pdev->dev, "regmap init failed\n");
> - return PTR_ERR(imx2_wdt.regmap);
> + return PTR_ERR(wdev->regmap);
> }
>
> - imx2_wdt.clk = devm_clk_get(&pdev->dev, NULL);
> - if (IS_ERR(imx2_wdt.clk)) {
> + wdev->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(wdev->clk)) {
> dev_err(&pdev->dev, "can't get Watchdog clock\n");
> - return PTR_ERR(imx2_wdt.clk);
> + return PTR_ERR(wdev->clk);
> }
>
> - imx2_wdt.timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
> - if (imx2_wdt.timeout != timeout)
> - dev_warn(&pdev->dev, "Initial timeout out of range! "
> - "Clamped from %u to %u\n", timeout, imx2_wdt.timeout);
> + wdog = &wdev->wdog;
> + wdog->info = &imx2_wdt_info;
> + wdog->ops = &imx2_wdt_ops;
> + wdog->min_timeout = 1;
> + wdog->max_timeout = IMX2_WDT_MAX_TIME;
>
> - setup_timer(&imx2_wdt.timer, imx2_wdt_timer_ping, 0);
> + clk_prepare_enable(wdev->clk);
>
> - imx2_wdt_miscdev.parent = &pdev->dev;
> - ret = misc_register(&imx2_wdt_miscdev);
> - if (ret)
> - goto fail;
> + regmap_read(wdev->regmap, IMX2_WDT_WRSR, &val);
> + wdog->bootstatus = val & IMX2_WDT_WRSR_TOUT ? WDIOF_CARDRESET : 0;
>
> - dev_info(&pdev->dev,
> - "IMX2+ Watchdog Timer enabled. timeout=%ds (nowayout=%d)\n",
> - imx2_wdt.timeout, nowayout);
> - return 0;
> + wdog->timeout = clamp_t(unsigned, timeout, 1, IMX2_WDT_MAX_TIME);
> + if (wdog->timeout != timeout)
> + dev_warn(&pdev->dev, "Initial timeout out of range! Clamped from %u to %u\n",
> + timeout, wdog->timeout);
> +
> + platform_set_drvdata(pdev, wdog);
> + watchdog_set_drvdata(wdog, wdev);
> + watchdog_set_nowayout(wdog, nowayout);
> + watchdog_init_timeout(wdog, timeout, &pdev->dev);
> +
> + setup_timer(&wdev->timer, imx2_wdt_timer_ping, (unsigned long)wdog);
>
> -fail:
> - imx2_wdt_miscdev.parent = NULL;
> - return ret;
> + imx2_wdt_ping_if_active(wdog);
> +
> + ret = watchdog_register_device(wdog);
> + if (ret) {
> + dev_err(&pdev->dev, "cannot register watchdog device\n");
> + return ret;
> + }
> +
> + dev_info(&pdev->dev, "timeout %d sec (nowayout=%d)\n",
> + wdog->timeout, nowayout);
> +
> + return 0;
> }
>
> static int __exit imx2_wdt_remove(struct platform_device *pdev)
> {
> - misc_deregister(&imx2_wdt_miscdev);
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
>
> - if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
> - del_timer_sync(&imx2_wdt.timer);
> + watchdog_unregister_device(wdog);
>
> - dev_crit(imx2_wdt_miscdev.parent,
> - "Device removed: Expect reboot!\n");
> + if (imx2_wdt_is_running(wdev)) {
> + del_timer_sync(&wdev->timer);
> + imx2_wdt_ping(wdog);
> + dev_crit(&pdev->dev, "Device removed: Expect reboot!\n");
> }
> -
> - imx2_wdt_miscdev.parent = NULL;
> return 0;
> }
>
> static void imx2_wdt_shutdown(struct platform_device *pdev)
> {
> - if (test_bit(IMX2_WDT_STATUS_STARTED, &imx2_wdt.status)) {
> - /* we are running, we need to delete the timer but will give
> - * max timeout before reboot will take place */
> - del_timer_sync(&imx2_wdt.timer);
> - imx2_wdt_set_timeout(IMX2_WDT_MAX_TIME);
> - imx2_wdt_ping();
> -
> - dev_crit(imx2_wdt_miscdev.parent,
> - "Device shutdown: Expect reboot!\n");
> + struct watchdog_device *wdog = platform_get_drvdata(pdev);
> + struct imx2_wdt_device *wdev = watchdog_get_drvdata(wdog);
> +
> + if (imx2_wdt_is_running(wdev)) {
> + /*
> + * We are running, we need to delete the timer but will
> + * give max timeout before reboot will take place
> + */
> + del_timer_sync(&wdev->timer);
> + imx2_wdt_set_timeout(wdog, IMX2_WDT_MAX_TIME);
> + imx2_wdt_ping(wdog);
> + dev_crit(&pdev->dev, "Device shutdown: Expect reboot!\n");
> }
> }
>
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