Re: [PATCH] rtc: ds1307: Enable battery backup on RX8130

[Marek Vasut <marex@denx.de>]

On 8/30/19 12:42 PM, Bastian Krause wrote:
> Hi Marek,

Hi,

> On 6/28/19 2:21 AM, Marek Vasut wrote:
>> The battery backup can be disabled on this RTC, e.g. if populated right
>> out of production. Force the battery backup bit on to enable it.
>>
>> Signed-off-by: Marek Vasut <marex@denx.de>
>> Cc: Arnaud Ebalard <arno@natisbad.org>
>> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
>> ---
>>  drivers/rtc/rtc-ds1307.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/rtc/rtc-ds1307.c b/drivers/rtc/rtc-ds1307.c
>> index 1f7e8aefc1eb..4af00cac1eff 100644
>> --- a/drivers/rtc/rtc-ds1307.c
>> +++ b/drivers/rtc/rtc-ds1307.c
>> @@ -121,6 +121,8 @@ enum ds_type {
>>  #define RX8130_REG_FLAG_AF		BIT(3)
>>  #define RX8130_REG_CONTROL0		0x1e
>>  #define RX8130_REG_CONTROL0_AIE		BIT(3)
>> +#define RX8130_REG_CONTROL1		0x0f
> 
> I think it is surprising that RX8130_REG_CONTROL0 is defined absolute
> and RX8130_REG_CONTROL1 must be used with chip offset. Having this
> defined consistently would be nice.

It's because this old patch was rebased from before the regmap changes
were even in.

>> +#define RX8130_REG_CONTROL1_INIEN	BIT(4)
>>  
>>  #define MCP794XX_REG_CONTROL		0x07
>>  #	define MCP794XX_BIT_ALM0_EN	0x10
>> @@ -1750,6 +1752,11 @@ static int ds1307_probe(struct i2c_client *client,
>>  				     DS1307_REG_HOUR << 4 | 0x08, hour);
>>  		}
>>  		break;
>> +	case rx_8130:
>> +		/* make sure that the backup battery is enabled */
>> +		regmap_write(ds1307->regmap, chip->offset + RX8130_REG_CONTROL1,
>> +			     RX8130_REG_CONTROL1_INIEN);
>> +		break;
> 
> Quick note: if a rechargeable battery or supercap is used the CHGEN bit
> must be set also.

By rechargable battery, you mean coin cell one ?

-- 
Best regards,
Marek Vasut

DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
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