Re: [PATCH v2 2/2] watchdog: s3c2410_wdt: Report when the watchdog reset the system

Doug Anderson
2013-12-06T21:08:19Z

Guenter,

On Fri, Dec 6, 2013 at 11:54 AM, Guenter Roeck <linux@roeck-us.net> wrote:
> On Thu, Dec 05, 2013 at 10:15:29AM -0800, Doug Anderson wrote:
>> A good watchdog driver is supposed to report when it was responsible
>> for resetting the system. Implement this for the s3c2410, at least on
>> exynos5250 and exynos5420 where we already have a pointer to the PMU
>> registers to read the information.
>>
>> Note that exynos4 SoCs also provide the reset status, but providing
>> that is left as an exercise for future changes and is not plumbed up
>> in this patch series. Also note the exynos4 SoCs don't appear to need
>> any PMU config, which is why this patch separates the concepts of
>> having PMU Registers vs. needing PMU Config.
>>
>> Signed-off-by: Doug Anderson <dianders@chromium.org>
>> ---
>> Changes in v2:
>> - Explained QUIRK organization in patch descritpion.
>> - Reduced indentation as per Olof and Tomasz suggestion.
>> - Now atop proposed v12 of Leela Krishna's patches.
>
> Hi Doug,
>
> The patch doesn't apply on top of v12, unfortunately.

OK, I'll re-send shortly.

>> - NEEDS => HAS, EXYNOS5 prefix
>>
>> drivers/watchdog/s3c2410_wdt.c | 42 +++++++++++++++++++++++++++++++++++++++---
>> 1 file changed, 39 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
>> index 6a00299..45a9503 100644
>> --- a/drivers/watchdog/s3c2410_wdt.c
>> +++ b/drivers/watchdog/s3c2410_wdt.c
>> @@ -62,9 +62,15 @@
>> #define CONFIG_S3C2410_WATCHDOG_ATBOOT (0)
>> #define CONFIG_S3C2410_WATCHDOG_DEFAULT_TIME (15)
>>
>> +#define EXYNOS5_RST_STAT_REG_OFFSET 0x0404
>> #define EXYNOS5_WDT_DISABLE_REG_OFFSET 0x0408
>> #define EXYNOS5_WDT_MASK_RESET_REG_OFFSET 0x040c
>> #define QUIRK_HAS_PMU_CONFIG (1 << 0)
>> +#define QUIRK_HAS_RST_STAT (1 << 1)
>> +
>> +/* These quirks require that we have a PMU register map */
>> +#define QUIRKS_HAVE_PMUREG (QUIRK_HAS_PMU_CONFIG | \
>> + QUIRK_HAS_RST_STAT)
>>
>> static bool nowayout = WATCHDOG_NOWAYOUT;
>> static int tmr_margin;
>> @@ -98,6 +104,9 @@ MODULE_PARM_DESC(debug, "Watchdog debug, set to >1 for debug (default 0)");
>> * timer reset functionality.
>> * @mask_bit: Bit number for the watchdog timer in the disable register and the
>> * mask reset register.
>> + * @rst_stat_reg: Offset in pmureg for the register that has the reset status.
>> + * @rst_stat_bit: Bit number in the rst_stat register indicating a watchdog
>> + * reset.
>> * @quirks: A bitfield of quirks.
>> */
>>
>> @@ -105,6 +114,8 @@ struct s3c2410_wdt_variant {
>> int disable_reg;
>> int mask_reset_reg;
>> int mask_bit;
>> + int rst_stat_reg;
>> + int rst_stat_bit;
>> u32 quirks;
>> };
>>
>> @@ -131,14 +142,20 @@ static const struct s3c2410_wdt_variant drv_data_exynos5250 = {
>> .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
>> .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
>> .mask_bit = 20,
>> - .quirks = QUIRK_HAS_PMU_CONFIG
>> + .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
>> + .rst_stat_bit = 20,
>> + .quirks = QUIRK_HAS_PMU_CONFIG |
>> + QUIRK_HAS_RST_STAT,
>
> Any reason not to use QUIRKS_HAVE_PMUREG ?

My intent was that the QUIRKS_HAVE_PMUREG is a list of quirks that
require a PMU register and is used for testing, not for setting. When
someone adds another quirk that requires the PMU Registers I don't
want that to automatically apply to old hardware.

>> };
>>
>> static const struct s3c2410_wdt_variant drv_data_exynos5420 = {
>> .disable_reg = EXYNOS5_WDT_DISABLE_REG_OFFSET,
>> .mask_reset_reg = EXYNOS5_WDT_MASK_RESET_REG_OFFSET,
>> .mask_bit = 0,
>> - .quirks = QUIRK_HAS_PMU_CONFIG
>> + .rst_stat_reg = EXYNOS5_RST_STAT_REG_OFFSET,
>> + .rst_stat_bit = 9,
>> + .quirks = QUIRK_HAS_PMU_CONFIG |
>> + QUIRK_HAS_RST_STAT,
>
> Same here. Even if you don't use QUIRKS_HAVE_PMUREG, the continuation line is not needed.

I will spin.

Thanks!

-Doug