On 12/06/2023 13:30:55+0200, Rasmus Villemoes wrote:
> Hook up support for reading the values of the SR_LBAT85 and SR_LBAT75
> bits. Translate the former to "battery low", and the latter to
> "battery empty or not-present".
>
> Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> ---
> drivers/rtc/rtc-isl12022.c | 41 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/drivers/rtc/rtc-isl12022.c b/drivers/rtc/rtc-isl12022.c
> index cb8f1d92e116..1b6659a9b33a 100644
> --- a/drivers/rtc/rtc-isl12022.c
> +++ b/drivers/rtc/rtc-isl12022.c
> @@ -203,7 +203,48 @@ static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
> return regmap_bulk_write(regmap, ISL12022_REG_SC, buf, sizeof(buf));
> }
>
> +static int isl12022_read_sr(struct regmap *regmap)
> +{
> + int ret;
> + u32 val;
> +
> + ret = regmap_read(regmap, ISL12022_REG_SR, &val);
> + if (ret < 0)
> + return ret;
> + return val;
> +}
> +
> +static int isl12022_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
> +{
> + struct regmap *regmap = dev_get_drvdata(dev);
> + u32 user = 0;
> + int ret;
> +
> + switch (cmd) {
> + case RTC_VL_READ:
> + ret = isl12022_read_sr(regmap);
> + if (ret < 0)
> + return ret;
> +
> + if (ret & ISL12022_SR_LBAT85)
> + user |= RTC_VL_BACKUP_LOW;
> +
> + if (ret & ISL12022_SR_LBAT75)
> + user |= RTC_VL_BACKUP_EMPTY;
> +
> + return put_user(user, (u32 __user *)arg);
> +
> + case RTC_VL_CLR:
> + return regmap_clear_bits(regmap, ISL12022_REG_SR,
> + ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75);
I'm against using RTC_VL_CLR for this as it deletes important
information (i.e. the date is probably invalid). You should let the RTC
clear the bits once the battery has been changed:
"The LBAT75 bit is set when the
VBAT has dropped below the pre-selected trip level, and will self
clear when the VBAT is above the pre-selected trip level at the
next detection cycle either by manual or automatic trigger."
> +
> + default:
> + return -ENOIOCTLCMD;
> + }
> +}
> +
> static const struct rtc_class_ops isl12022_rtc_ops = {
> + .ioctl = isl12022_rtc_ioctl,
> .read_time = isl12022_rtc_read_time,
> .set_time = isl12022_rtc_set_time,
> };
> --
> 2.37.2
>
--
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
