Hi Marek,
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@xxxxxxx>
> Cc: Arnaud Ebalard <arno@xxxxxxxxxxxx>
> Cc: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx>
> ---
> 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.
> +#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.
Regards,
Bastian
> default:
> break;
> }
>
>
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