Re: [PATCH 4/4] watchdog: pnx4008: convert driver to use the watchdog framework

[Roland Stigge <stigge@antcom.de>]

On 02/02/2012 06:48 PM, Wolfram Sang wrote:
> Make this driver a user of the watchdog framework and remove parts now handled
> by the core. Tested on a custom lpc32xx-board.
> 
> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
> ---
>  drivers/watchdog/Kconfig       |    1 +
>  drivers/watchdog/pnx4008_wdt.c |  185 +++++++--------------------------------
>  2 files changed, 35 insertions(+), 151 deletions(-)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 877b107..f6827e4 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -234,6 +234,7 @@ config OMAP_WATCHDOG
>  config PNX4008_WATCHDOG
>  	tristate "PNX4008 and LPC32XX Watchdog"
>  	depends on ARCH_PNX4008 || ARCH_LPC32XX
> +	select WATCHDOG_CORE
>  	help
>  	  Say Y here if to include support for the watchdog timer
>  	  in the PNX4008 or LPC32XX processor.
> diff --git a/drivers/watchdog/pnx4008_wdt.c b/drivers/watchdog/pnx4008_wdt.c
> index 6010602..eb86e3e 100644
> --- a/drivers/watchdog/pnx4008_wdt.c
> +++ b/drivers/watchdog/pnx4008_wdt.c
> @@ -8,29 +8,27 @@
>   * Based on sa1100 driver,
>   * Copyright (C) 2000 Oleg Drokin <green@crimea.edu>
>   *
> - * 2005-2006 (c) MontaVista Software, Inc. 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.
> + * 2005-2006 (c) MontaVista Software, Inc.
> + *
> + * (C) 2012 Wolfram Sang, Pengutronix
> + *
> + * 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/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/types.h>
>  #include <linux/kernel.h>
> -#include <linux/fs.h>
>  #include <linux/miscdevice.h>
>  #include <linux/watchdog.h>
>  #include <linux/init.h>
> -#include <linux/bitops.h>
> -#include <linux/ioport.h>
> -#include <linux/device.h>
>  #include <linux/platform_device.h>
>  #include <linux/clk.h>
> -#include <linux/spinlock.h>
> -#include <linux/uaccess.h>
>  #include <linux/io.h>
>  #include <linux/slab.h>
> +#include <linux/err.h>
>  #include <mach/hardware.h>
>  
>  #define MODULE_NAME "PNX4008-WDT: "
> @@ -80,22 +78,11 @@
>  static int nowayout = WATCHDOG_NOWAYOUT;
>  static int heartbeat = DEFAULT_HEARTBEAT;
>  
> -static DEFINE_SPINLOCK(io_lock);
> -static unsigned long wdt_status;
> -#define WDT_IN_USE        0
> -#define WDT_OK_TO_CLOSE   1
> -#define WDT_REGION_INITED 2
> -#define WDT_DEVICE_INITED 3
> -
> -static unsigned long boot_status;
> -
>  static void __iomem	*wdt_base;
>  struct clk		*wdt_clk;
>  
> -static void wdt_enable(void)
> +static int pnx4008_wdt_start(struct watchdog_device *wdd)
>  {
> -	spin_lock(&io_lock);
> -
>  	/* stop counter, initiate counter reset */
>  	writel(RESET_COUNT, WDTIM_CTRL(wdt_base));
>  	/*wait for reset to complete. 100% guarantee event */
> @@ -109,144 +96,37 @@ static void wdt_enable(void)
>  	writel(MATCH_INT, WDTIM_INT(wdt_base));
>  	/* the longest pulse period 65541/(13*10^6) seconds ~ 5 ms. */
>  	writel(0xFFFF, WDTIM_PULSE(wdt_base));
> -	writel(heartbeat * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
> +	writel(wdd->timeout * WDOG_COUNTER_RATE, WDTIM_MATCH0(wdt_base));
>  	/*enable counter, stop when debugger active */
>  	writel(COUNT_ENAB | DEBUG_EN, WDTIM_CTRL(wdt_base));
>  
> -	spin_unlock(&io_lock);
> +	return 0;
>  }
>  
> -static void wdt_disable(void)
> +static int pnx4008_wdt_stop(struct watchdog_device *wdd)
>  {
> -	spin_lock(&io_lock);
> -
>  	writel(0, WDTIM_CTRL(wdt_base));	/*stop counter */
>  
> -	spin_unlock(&io_lock);
> -}
> -
> -static int pnx4008_wdt_open(struct inode *inode, struct file *file)
> -{
> -	int ret;
> -
> -	if (test_and_set_bit(WDT_IN_USE, &wdt_status))
> -		return -EBUSY;
> -
> -	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
> -
> -	ret = clk_enable(wdt_clk);
> -	if (ret) {
> -		clear_bit(WDT_IN_USE, &wdt_status);
> -		return ret;
> -	}
> -
> -	wdt_enable();
> -
> -	return nonseekable_open(inode, file);
> -}
> -
> -static ssize_t pnx4008_wdt_write(struct file *file, const char *data,
> -					size_t len, loff_t *ppos)
> -{
> -	if (len) {
> -		if (!nowayout) {
> -			size_t i;
> -
> -			clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
> -
> -			for (i = 0; i != len; i++) {
> -				char c;
> -
> -				if (get_user(c, data + i))
> -					return -EFAULT;
> -				if (c == 'V')
> -					set_bit(WDT_OK_TO_CLOSE, &wdt_status);
> -			}
> -		}
> -		wdt_enable();
> -	}
> -
> -	return len;
> +	return 0;
>  }
>  
> -static const struct watchdog_info ident = {
> +static const struct watchdog_info pnx4008_wdt_ident = {
>  	.options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE |
>  	    WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING,
>  	.identity = "PNX4008 Watchdog",
>  };
>  
> -static long pnx4008_wdt_ioctl(struct file *file, unsigned int cmd,
> -				unsigned long arg)
> -{
> -	int ret = -ENOTTY;
> -	int time;
> -
> -	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(boot_status, (int *)arg);
> -		break;
> -
> -	case WDIOC_KEEPALIVE:
> -		wdt_enable();
> -		ret = 0;
> -		break;
> -
> -	case WDIOC_SETTIMEOUT:
> -		ret = get_user(time, (int *)arg);
> -		if (ret)
> -			break;
> -
> -		if (time <= 0 || time > MAX_HEARTBEAT) {
> -			ret = -EINVAL;
> -			break;
> -		}
> -
> -		heartbeat = time;
> -		wdt_enable();
> -		/* Fall through */
> -
> -	case WDIOC_GETTIMEOUT:
> -		ret = put_user(heartbeat, (int *)arg);
> -		break;
> -	}
> -	return ret;
> -}
> -
> -static int pnx4008_wdt_release(struct inode *inode, struct file *file)
> -{
> -	if (!test_bit(WDT_OK_TO_CLOSE, &wdt_status))
> -		printk(KERN_WARNING "WATCHDOG: Device closed unexpectedly\n");
> -
> -	wdt_disable();
> -	clk_disable(wdt_clk);
> -	clear_bit(WDT_IN_USE, &wdt_status);
> -	clear_bit(WDT_OK_TO_CLOSE, &wdt_status);
> -
> -	return 0;
> -}
> -
> -static const struct file_operations pnx4008_wdt_fops = {
> +static struct watchdog_ops pnx4008_wdt_ops = {
>  	.owner = THIS_MODULE,
> -	.llseek = no_llseek,
> -	.write = pnx4008_wdt_write,
> -	.unlocked_ioctl = pnx4008_wdt_ioctl,
> -	.open = pnx4008_wdt_open,
> -	.release = pnx4008_wdt_release,
> +	.start = pnx4008_wdt_start,
> +	.stop = pnx4008_wdt_stop,
>  };
>  
> -static struct miscdevice pnx4008_wdt_miscdev = {
> -	.minor = WATCHDOG_MINOR,
> -	.name = "watchdog",
> -	.fops = &pnx4008_wdt_fops,
> +static struct watchdog_device pnx4008_wdd = {
> +	.info = &pnx4008_wdt_ident,
> +	.ops = &pnx4008_wdt_ops,
> +	.min_timeout = 1,
> +	.max_timeout = MAX_HEARTBEAT,
>  };
>  
>  static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
> @@ -270,17 +150,19 @@ static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
>  	if (ret)
>  		goto put_clk;
>  
> -	ret = misc_register(&pnx4008_wdt_miscdev);
> +	pnx4008_wdd.timeout = heartbeat;
> +	pnx4008_wdd.bootstatus = (readl(WDTIM_RES(wdt_base)) & WDOG_RESET) ?
> +				WDIOF_CARDRESET : 0;
> +
> +	watchdog_set_nowayout(&pnx4008_wdd, nowayout);
> +
> +	ret = watchdog_register_device(&pnx4008_wdd);
>  	if (ret < 0) {
> -		dev_err(&pdev->dev, "cannot register misc device\n");
> +		dev_err(&pdev->dev, "cannot register watchdog device\n");
>  		goto disable_clk;
>  	}
>  
> -	boot_status = (readl(WDTIM_RES(wdt_base)) &
> -		WDOG_RESET) ? WDIOF_CARDRESET : 0;
> -	wdt_disable();		/*disable for now */
> -	clk_disable(wdt_clk);
> -	set_bit(WDT_DEVICE_INITED, &wdt_status);
> +	pnx4008_wdt_stop(&pnx4008_wdd);	/* disable for now */
>  
>  	dev_info(&pdev->dev, "PNX4008 Watchdog Timer: heartbeat %d sec\n",
>  			heartbeat);
> @@ -296,7 +178,7 @@ static int __devinit pnx4008_wdt_probe(struct platform_device *pdev)
>  
>  static int __devexit pnx4008_wdt_remove(struct platform_device *pdev)
>  {
> -	misc_deregister(&pnx4008_wdt_miscdev);
> +	watchdog_unregister_device(&pnx4008_wdd);
>  
>  	clk_disable(wdt_clk);
>  	clk_put(wdt_clk);
> @@ -315,7 +197,8 @@ static struct platform_driver platform_wdt_driver = {
>  
>  module_platform_driver(platform_wdt_driver);
>  
> -MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com>");
> +MODULE_AUTHOR("MontaVista Software, Inc. <source@mvista.com> and "
> +	"Wolfram Sang <w.sang@pengutronix.de>");
>  MODULE_DESCRIPTION("PNX4008 Watchdog Driver");
>  
>  module_param(heartbeat, int, 0);

Tested-by: Roland Stigge <stigge@antcom.de>