Re: [PATCH v5 03/10] watchdog: at91rm9200: use the system timer syscon

[Guenter Roeck <linux@roeck-us.net>]

On Thu, Mar 12, 2015 at 01:07:27PM +0100, Alexandre Belloni wrote:
> Use a syscon regmap to access the system timer registers.
> 
> Also, rename the driver atmel_st_watchdog to stop conflicting with
> at91sam9_wdt.c
> 
> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

> ---
>  drivers/watchdog/Kconfig          |  2 +-
>  drivers/watchdog/at91rm9200_wdt.c | 29 ++++++++++++++++++++++-------
>  2 files changed, 23 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 16f202350997..ce4f3a7f95fd 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -154,7 +154,7 @@ config ARM_SP805_WATCHDOG
>  
>  config AT91RM9200_WATCHDOG
>  	tristate "AT91RM9200 watchdog"
> -	depends on SOC_AT91RM9200
> +	depends on SOC_AT91RM9200 && MFD_SYSCON
>  	help
>  	  Watchdog timer embedded into AT91RM9200 chips. This will reboot your
>  	  system when the timeout is reached.
> diff --git a/drivers/watchdog/at91rm9200_wdt.c b/drivers/watchdog/at91rm9200_wdt.c
> index d244112d5b6f..e6fa87d85de3 100644
> --- a/drivers/watchdog/at91rm9200_wdt.c
> +++ b/drivers/watchdog/at91rm9200_wdt.c
> @@ -17,22 +17,25 @@
>  #include <linux/init.h>
>  #include <linux/io.h>
>  #include <linux/kernel.h>
> +#include <linux/mfd/syscon.h>
> +#include <linux/mfd/syscon/atmel-st.h>
>  #include <linux/miscdevice.h>
>  #include <linux/module.h>
>  #include <linux/moduleparam.h>
>  #include <linux/platform_device.h>
> +#include <linux/regmap.h>
>  #include <linux/types.h>
>  #include <linux/watchdog.h>
>  #include <linux/uaccess.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
> -#include <mach/at91_st.h>
>  
>  #define WDT_DEFAULT_TIME	5	/* seconds */
>  #define WDT_MAX_TIME		256	/* seconds */
>  
>  static int wdt_time = WDT_DEFAULT_TIME;
>  static bool nowayout = WATCHDOG_NOWAYOUT;
> +static struct regmap *regmap_st;
>  
>  module_param(wdt_time, int, 0);
>  MODULE_PARM_DESC(wdt_time, "Watchdog time in seconds. (default="
> @@ -55,7 +58,7 @@ static unsigned long at91wdt_busy;
>   */
>  static inline void at91_wdt_stop(void)
>  {
> -	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN);
> +	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN);
>  }
>  
>  /*
> @@ -63,9 +66,9 @@ static inline void at91_wdt_stop(void)
>   */
>  static inline void at91_wdt_start(void)
>  {
> -	at91_st_write(AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
> +	regmap_write(regmap_st, AT91_ST_WDMR, AT91_ST_EXTEN | AT91_ST_RSTEN |
>  				(((65536 * wdt_time) >> 8) & AT91_ST_WDV));
> -	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
> +	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
>  }
>  
>  /*
> @@ -73,7 +76,7 @@ static inline void at91_wdt_start(void)
>   */
>  static inline void at91_wdt_reload(void)
>  {
> -	at91_st_write(AT91_ST_CR, AT91_ST_WDRST);
> +	regmap_write(regmap_st, AT91_ST_CR, AT91_ST_WDRST);
>  }
>  
>  /* ......................................................................... */
> @@ -203,12 +206,24 @@ static struct miscdevice at91wdt_miscdev = {
>  
>  static int at91wdt_probe(struct platform_device *pdev)
>  {
> +	struct device *dev = &pdev->dev;
> +	struct device *parent;
>  	int res;
>  
>  	if (at91wdt_miscdev.parent)
>  		return -EBUSY;
>  	at91wdt_miscdev.parent = &pdev->dev;
>  
> +	parent = dev->parent;
> +	if (!parent) {
> +		dev_err(dev, "no parent\n");
> +		return -ENODEV;
> +	}
> +
> +	regmap_st = syscon_node_to_regmap(parent->of_node);
> +	if (!regmap_st)
> +		return -ENODEV;
> +
>  	res = misc_register(&at91wdt_miscdev);
>  	if (res)
>  		return res;
> @@ -267,7 +282,7 @@ static struct platform_driver at91wdt_driver = {
>  	.suspend	= at91wdt_suspend,
>  	.resume		= at91wdt_resume,
>  	.driver		= {
> -		.name	= "at91_wdt",
> +		.name	= "atmel_st_watchdog",
>  		.of_match_table = at91_wdt_dt_ids,
>  	},
>  };
> @@ -296,4 +311,4 @@ module_exit(at91_wdt_exit);
>  MODULE_AUTHOR("Andrew Victor");
>  MODULE_DESCRIPTION("Watchdog driver for Atmel AT91RM9200");
>  MODULE_LICENSE("GPL");
> -MODULE_ALIAS("platform:at91_wdt");
> +MODULE_ALIAS("platform:atmel_st_watchdog");
> -- 
> 2.1.0
> 
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