Re: [rtc-linux] [PATCH] rtc: s5m: fix to update ctrl register

[Krzysztof Kozlowski]

On 17.08.2015 10:47, Joonyoung Shim wrote:
> Hi,
> 
> On 08/13/2015 07:02 PM, Krzysztof Kozlowski wrote:
>> W dniu 13.08.2015 o 17:49, Joonyoung Shim pisze:
>>> According to datasheet, the S2MPS13X and S2MPS14X should update write
>>> buffer via setting WUDR bit to high after ctrl register is updated.
>>
>> Hi,
>>
>> I cannot find this information in S2MPS14 datasheet. On which page is it?
>>
> 
> I got below information from S2MPS14_Data Sheet_REV0.1 document.
> 
> 5.2.2.3 RTC_UPDATE
> ...
> 
> NOTE: 
> 1.  For write Time Registers (0x00, 0x04~0x0A) & Alarm 0&1 Registers 
> (0x0B~0x18), set WUDR bit to high.

Right, I have too but it does not say anything about control register.
It mentions only time, alarm 0 and alarm 1 registers, not control.

> 
>>
>>>
>>> If not, ALARM interrupt of rtc-s5m doesn't happen first time when i use
>>> tools/testing/selftests/timers/rtctest.c test program and hour format is
>>> used to 12 hour mode in Odroid-XU3 board.
>>
>> Two questions here:
>> 1. Earlier you mentioned S2MPS1[34], now Odroid XU3 which has S2MPS11.
>> Are you sure that this applies to all of them (S2MPS11, S2MPS13 and
>> S2MP14)? There are some minor differences between them so I would not be
>> surprised if only some of them required this action.
>>
> 
> I'm not sure about that because i don't have S2MPS11 datasheet. I just
> got the information that S2MPS11 also use S2MPS14 rtc from sec-core mfd
> driver,

Yeah, I added it. But these RTC modules are slightly different,
especially S2MPS14, so you cannot assume that they are the same after
looking at mainline code.

> 
> static const struct mfd_cell s2mps11_devs[] = {                                                                       
>         {                                                                                                             
>                 .name = "s2mps11-pmic",                                                                               
>         }, {                                                                                                          
>                 .name = "s2mps14-rtc",                                                                                
>         }, {                                                                                                          
>                 .name = "s2mps11-clk",                                                                                
>                 .of_compatible = "samsung,s2mps11-clk",                                                               
>         }                                                                                                             
> };
> 
>> 2. The driver operates in 24-hour omode. Actually it sets the 24-hour
>> mode just before your new regmap_update_bits() call. What do you mean by
>> 12-hour mode?
>>
> 
> RTC_CTRL register value is 0 until write buffer is updated, so it is
> used to 12-hour mode.

I mean what do you have in mind by saying:
"... and hour format is used to 12 hour mode in Odroid-XU3 board."
The hour format is set by driver to 24h mode.


> 
>>> Signed-off-by: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx>
>>> Cc: <stable@xxxxxxxxxxxxxxx>
>>
>> Thanks for putting a cc-stable tag. How far this should be ported? If
>> this is needed only for S2MPS11 then v4.1. If all of them then probably
>> for earlier version?
>>
> 
> If find exact version, i think it will be a version after below commit
> was applied.
> 
> The commit 0c5deb1ea92f("rtc: s5m: add support for S2MPS14 RTC")
> 
> $ git name-rev 0c5deb1ea92f
> 0c5deb1ea92f tags/v3.16-rc1~53^2~1

Hmmm... I am not against the patch (especially that it matches source
code of SM-G900H with S2MPS11) but I have doubts about affected
chipsets. My Odroid (probably because of bootloader), S2MPS13 and
S2MPS14 do not need it. This confuses me...

Best regards,
Krzysztof

> 
> Thanks.
> 
>> Best regards,
>> Krzysztof
>>
>>> ---
>>>  drivers/rtc/rtc-s5m.c | 12 ++++++++++++
>>>  1 file changed, 12 insertions(+)
>>>
>>> diff --git a/drivers/rtc/rtc-s5m.c b/drivers/rtc/rtc-s5m.c
>>> index 8c70d78..03828bb 100644
>>> --- a/drivers/rtc/rtc-s5m.c
>>> +++ b/drivers/rtc/rtc-s5m.c
>>> @@ -635,6 +635,18 @@ static int s5m8767_rtc_init_reg(struct s5m_rtc_info *info)
>>>  	case S2MPS13X:
>>>  		data[0] = (0 << BCD_EN_SHIFT) | (1 << MODEL24_SHIFT);
>>>  		ret = regmap_write(info->regmap, info->regs->ctrl, data[0]);
>>> +		if (ret < 0)
>>> +			break;
>>> +
>>> +		ret = regmap_update_bits(info->regmap,
>>> +				info->regs->rtc_udr_update,
>>> +				info->regs->rtc_udr_mask,
>>> +				info->regs->rtc_udr_mask);
>>> +		if (ret < 0)
>>> +			break;
>>> +
>>> +		ret = s5m8767_wait_for_udr_update(info);
>>> +
>>>  		break;
>>>  
>>>  	default:
>>>
>>
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> 
> 

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