On 13/02/2023 10:50:17+0100, Javier Carrasco wrote:
> The quartz oscillator load capacitance of the PCF85263 and PCF85363 can
> be adjusted to 6 pF, 7 pF (default) and 12.5 pF with the CL[1:0] bits in
> the oscillator control register (address 25h).
>
> Signed-off-by: Javier Carrasco <javier.carrasco@xxxxxxxxxxxxxx>
> ---
> drivers/rtc/rtc-pcf85363.c | 37 ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 36 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c
> index c05b722f0060..941f9264cf0a 100644
> --- a/drivers/rtc/rtc-pcf85363.c
> +++ b/drivers/rtc/rtc-pcf85363.c
> @@ -101,6 +101,10 @@
> #define PIN_IO_INTA_OUT 2
> #define PIN_IO_INTA_HIZ 3
>
> +#define OSC_CAP_SEL GENMASK(1, 0)
> +#define OSC_CAP_6000 0x01
> +#define OSC_CAP_12500 0x02
> +
> #define STOP_EN_STOP BIT(0)
>
> #define RESET_CPR 0xa4
> @@ -117,6 +121,32 @@ struct pcf85x63_config {
> unsigned int num_nvram;
> };
>
> +static int pcf85363_load_capacitance(struct pcf85363 *pcf85363, struct device_node *node)
> +{
> + u32 load = 7000;
> + u8 value = 0;
> +
> + of_property_read_u32(node, "quartz-load-femtofarads", &load);
> +
> + switch (load) {
> + default:
> + dev_warn(&pcf85363->rtc->dev, "Unknown quartz-load-femtofarads value: %d. Assuming 7000",
> + load);
> + fallthrough;
> + case 7000:
> + break;
> + case 6000:
> + value |= OSC_CAP_6000;
Why are you using the |= operator?
> + break;
> + case 12500:
> + value |= OSC_CAP_12500;
> + break;
> + }
> +
> + return regmap_update_bits(pcf85363->regmap, CTRL_OSCILLATOR,
> + OSC_CAP_SEL, value);
> +}
> +
> static int pcf85363_rtc_read_time(struct device *dev, struct rtc_time *tm)
> {
> struct pcf85363 *pcf85363 = dev_get_drvdata(dev);
> @@ -372,7 +402,7 @@ static int pcf85363_probe(struct i2c_client *client)
> .reg_write = pcf85363_nvram_write,
> },
> };
> - int ret, i;
> + int ret, i, err;
>
> if (data)
> config = data;
> @@ -394,6 +424,11 @@ static int pcf85363_probe(struct i2c_client *client)
> if (IS_ERR(pcf85363->rtc))
> return PTR_ERR(pcf85363->rtc);
>
> + err = pcf85363_load_capacitance(pcf85363, client->dev.of_node);
> + if (err < 0)
> + dev_warn(&client->dev, "failed to set xtal load capacitance: %d",
> + err);
> +
> pcf85363->rtc->ops = &rtc_ops;
> pcf85363->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
> pcf85363->rtc->range_max = RTC_TIMESTAMP_END_2099;
> --
> 2.37.2
>
>
> Javier Carrasco
> Research and Development
>
> Wolfvision GmbH
> Oberes Ried 14 | 6833 Klaus | Austria
> Tel: +43 5523 52250 <tel:+43552352250> | Mail: javier.carrasco@xxxxxxxxxxxxxx <mailto:javier.carrasco@xxxxxxxxxxxxxx>
>
> Website: wolfvision.com <www.wolfvision.com>
> Firmenbuch / Commercial Register: FN283521v Feldkirch/Austria
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
