diff options
| author | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2021-10-18 17:19:31 +0200 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@bootlin.com> | 2021-10-18 17:20:50 +0200 |
| commit | 0d20e9fb1262b1f9ac895b287db892bc75b05b84 (patch) | |
| tree | 3d8e56cfa4e52674c2a8fbb0abb7c9b277676856 /drivers/rtc | |
| parent | a6d8c6e1a5c6fb982964861dc84c0c7cb0151c7c (diff) | |
| download | linux-0d20e9fb1262b1f9ac895b287db892bc75b05b84.tar.bz2 | |
rtc: add BSM parameter
BSM or Backup Switch Mode is a common feature on RTCs, allowing to select
how the RTC will decide when to switch from its primary power supply to the
backup power supply. It is necessary to be able to set it from userspace as
there are uses cases where it has to be done dynamically.
Supported values are:
RTC_BSM_DISABLED: disabled
RTC_BSM_DIRECT: switching will happen as soon as Vbackup > Vdd
RTC_BSM_LEVEL: switching will happen around a threshold, usually with an
hysteresis
RTC_BSM_STANDBY: switching will not happen until Vdd > Vbackup, this is
useful to ensure the RTC doesn't draw any power until the device is first
powered on.
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://lore.kernel.org/r/20211018151933.76865-6-alexandre.belloni@bootlin.com
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/dev.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c index abee1fc4705e..e104972a28fd 100644 --- a/drivers/rtc/dev.c +++ b/drivers/rtc/dev.c @@ -409,7 +409,10 @@ static long rtc_dev_ioctl(struct file *file, break; default: - err = -EINVAL; + if (rtc->ops->param_get) + err = rtc->ops->param_get(rtc->dev.parent, ¶m); + else + err = -EINVAL; } if (!err) @@ -436,7 +439,10 @@ static long rtc_dev_ioctl(struct file *file, return rtc_set_offset(rtc, param.svalue); default: - err = -EINVAL; + if (rtc->ops->param_set) + err = rtc->ops->param_set(rtc->dev.parent, ¶m); + else + err = -EINVAL; } break; |