On Wed, Jan 13, 2021 at 12:27:42PM +0100, Philipp Rosenberger wrote:
> The datasheet of the PCF2127 states,it is recommended to process an OTP
s/,/, /
> refresh once the power is up and the oscillator is operating stable. The
> OTP refresh takes less than 100 ms to complete.
>
> Signed-off-by: Philipp Rosenberger <p.rosenberger@xxxxxxxxxx>
> ---
> drivers/rtc/rtc-pcf2127.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
> diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
> index 378b1ce812d6..ca56dba64e79 100644
> --- a/drivers/rtc/rtc-pcf2127.c
> +++ b/drivers/rtc/rtc-pcf2127.c
> @@ -58,6 +58,9 @@
> #define PCF2127_REG_ALARM_DM 0x0D
> #define PCF2127_REG_ALARM_DW 0x0E
> #define PCF2127_BIT_ALARM_AE BIT(7)
> +/* CLKOUT control register */
> +#define PCF2127_REG_CLKOUT 0x0f
> +#define PCF2127_BIT_CLKOUT_OTPR BIT(5)
> /* Watchdog registers */
> #define PCF2127_REG_WD_CTL 0x10
> #define PCF2127_BIT_WD_CTL_TF0 BIT(0)
> @@ -630,6 +633,19 @@ static int pcf2127_probe(struct device *dev, struct regmap *regmap,
> dev_warn(dev, "Watchdog and alarm functions might not work properly\n");
> }
>
> + /*
> + * Set the OTP refresh bit unconditionally. If an OTP refresh was
> + * already done the bit is already set and will not rerun the refresh
> + * operation.
> + */
> + ret = regmap_set_bits(pcf2127->regmap, PCF2127_REG_CLKOUT,
> + PCF2127_BIT_CLKOUT_OTPR);
> + if (ret < 0) {
> + dev_err(dev, "%s: OTP refresh (clkout_ctrl) failed.\n", __func__);
> + return ret;
> + }
> + msleep(100);
This unconditional sleep isn't so nice. Maybe it makes sense to only do
this when the chip reports a power loss?
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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