Hello Esben,
On 10/09/2024 12:27:11+0200, Esben Haabendal wrote:
> The ISL12022 RTC has a combined INT/fOUT pin, which can be used for alarm
> interrupt when frequency output is not enabled.
>
> The device-tree bindings should ensure that interrupt and clock output is
> not enabled at the same time.
Ideally, we would get a pinmuxing part in the driver to ensure this ;)
> +static int isl12022_rtc_read_alarm(struct device *dev,
> + struct rtc_wkalrm *alarm)
> +{
> + struct rtc_time *const tm = &alarm->time;
> + struct isl12022 *isl12022 = dev_get_drvdata(dev);
> + struct regmap *regmap = isl12022->regmap;
> + uint8_t buf[ISL12022_ALARM_SECTION_LEN];
> + int ret, yr, i;
> +
> + ret = regmap_bulk_read(regmap, ISL12022_ALARM_SECTION,
> + buf, sizeof(buf));
> + if (ret) {
> + dev_err(dev, "%s: reading ALARM registers failed\n",
> + __func__);
I don't really like those error messages because there is nothing the
user can actually do apart from trying again and this bloats the kernel.
> + /* The alarm doesn't store the year so get it from the rtc section */
> + ret = regmap_read(regmap, ISL12022_REG_YR, &yr);
> + if (ret) {
> + dev_err(dev, "%s: reading YR register failed\n", __func__);
Ditto
> + isl12022->rtc = rtc;
>
> rtc->ops = &isl12022_rtc_ops;
> rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
> rtc->range_max = RTC_TIMESTAMP_END_2099;
>
> + if (client->irq > 0) {
> + ret = isl12022_setup_irq(isl12022, client->irq);
You can't do this in probe, the RTC lifecycle is longer than the linux
system. Or said differently: "oh no, my linux has rebooted and now I
lost my future alarm" ;)
> + if (ret)
> + return ret;
> + } else {
> + clear_bit(RTC_FEATURE_ALARM, rtc->features);
> + }
> +
> return devm_rtc_register_device(rtc);
> }
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
