On Thu, Oct 09, 2014 at 09:06:29PM +0200, Johan Hovold wrote:
> Some legacy RTC IP revisions has a power-up reset flag in the status
> register that later revisions lack.
> 
> As this flag is always read back as set on later revisions (or is
> overloaded with a different flag), make sure to only clear the flag and
> print the info message on legacy platforms.
> 
> Signed-off-by: Johan Hovold <jo...@kernel.org>

Reviewed-by: Felipe Balbi <ba...@ti.com>

> ---
>  drivers/rtc/rtc-omap.c | 23 +++++++++++++++++------
>  1 file changed, 17 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
> index 1c58920b0c88..0ef016553a97 100644
> --- a/drivers/rtc/rtc-omap.c
> +++ b/drivers/rtc/rtc-omap.c
> @@ -118,6 +118,12 @@
>   */
>  #define OMAP_RTC_HAS_32KCLK_EN               BIT(2)
>  
> +/*
> + * Some legacy RTC IP revisions has a power-up reset flag which later
> + * revisions lack.
> + */
> +#define OMAP_RTC_HAS_POWER_UP_RESET  BIT(3)
> +
>  static void __iomem  *rtc_base;
>  
>  #define rtc_read(addr)               readb(rtc_base + (addr))
> @@ -347,6 +353,7 @@ static int omap_rtc_timer;
>  static struct platform_device_id omap_rtc_devtype[] = {
>       {
>               .name   = DRIVER_NAME,
> +             .driver_data = OMAP_RTC_HAS_POWER_UP_RESET,
>       },
>       [OMAP_RTC_DATA_AM3352_IDX] = {
>               .name   = "am3352-rtc",
> @@ -376,7 +383,7 @@ static int __init omap_rtc_probe(struct platform_device 
> *pdev)
>  {
>       struct resource         *res;
>       struct rtc_device       *rtc;
> -     u8                      reg, new_ctrl;
> +     u8                      reg, mask, new_ctrl;
>       const struct platform_device_id *id_entry;
>       const struct of_device_id *of_id;
>  
> @@ -429,12 +436,16 @@ static int __init omap_rtc_probe(struct platform_device 
> *pdev)
>  
>       /* clear old status */
>       reg = rtc_read(OMAP_RTC_STATUS_REG);
> -     if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
> -             dev_info(&pdev->dev, "RTC power up reset detected\n");
> -             rtc_write(OMAP_RTC_STATUS_POWER_UP, OMAP_RTC_STATUS_REG);
> +
> +     mask = OMAP_RTC_STATUS_ALARM;
> +     if (id_entry->driver_data & OMAP_RTC_HAS_POWER_UP_RESET) {
> +             mask |= OMAP_RTC_STATUS_POWER_UP;
> +             if (reg & OMAP_RTC_STATUS_POWER_UP)
> +                     dev_info(&pdev->dev, "RTC power up reset detected\n");
>       }
> -     if (reg & (u8) OMAP_RTC_STATUS_ALARM)
> -             rtc_write(OMAP_RTC_STATUS_ALARM, OMAP_RTC_STATUS_REG);
> +
> +     if (reg & mask)
> +             rtc_write(reg & mask, OMAP_RTC_STATUS_REG);
>  
>       /* handle periodic and alarm irqs */
>       if (devm_request_irq(&pdev->dev, omap_rtc_timer, rtc_irq, 0,
> -- 
> 2.0.4
> 

-- 
balbi

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