rtc: add rtc-driver for HID sensors of type time

This driver makes the time from HID sensors (hubs) which are offering
such available like any other RTC does.

It is necessary that all values like year, month etc, are send as
8bit values (1 byte each) and all of them in 1 report. Also the
spec HUTRR39b doesn't define the range of the year field, we
tread it as 0 - 99 because that's what most RTCs I know about are
offering.

Currently the time can only be read. Setting the time must be done
through sending a report (or a feature). The spec currently doesn't
define how and I'm not sure if I just should define something by myself.

Signed-off-by: Alexander Holler <holler@ahsoftware.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 16 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index d0cea02..eed335c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1165,4 +1165,20 @@ config RTC_DRV_SNVS
 	   This driver can also be built as a module, if so, the module
 	   will be called "rtc-snvs".
 
+comment "HID Sensor RTC drivers"
+
+config RTC_DRV_HID_SENSOR_TIME
+	tristate "HID Sensor Time"
+	depends on USB_HID
+	select IIO
+	select HID_SENSOR_HUB
+	select HID_SENSOR_IIO_COMMON
+	help
+	  Say yes here to build support for the HID Sensors of type Time.
+	  This drivers makes such sensors available as RTCs.
+
+	  If this driver is compiled as a module, it will be named
+	  rtc-hid-sensor-time.
+
+
 endif # RTC_CLASS