diff options
| author | Javier Carrasco <javier.carrasco@wolfvision.net> | 2023-02-15 09:18:15 +0100 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2023-02-22 15:31:01 +0100 |
| commit | fd9a6a13949af81062f4cd04f2c1b28ca5311e71 (patch) | |
| tree | 0adaa3a95c8937eb267e0d9027b18337d317e412 /drivers/rtc/rtc-pcf85363.c | |
| parent | 1b2f85a8bac67b9909f2ee4be1bc11548a7aeaf3 (diff) | |
| download | linux-fd9a6a13949af81062f4cd04f2c1b28ca5311e71.tar.gz | |
rtc: pcf85363: add support for the quartz-load-femtofarads property
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@wolfvision.net>
Link: https://lore.kernel.org/r/20230215081815.3141776-3-javier.carrasco@wolfvision.net
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Diffstat (limited to 'drivers/rtc/rtc-pcf85363.c')
| -rw-r--r-- | drivers/rtc/rtc-pcf85363.c | 37 |
1 files changed, 36 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-pcf85363.c b/drivers/rtc/rtc-pcf85363.c index 5de323acd1786..8958eadf1c3ef 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; + 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; |