[PATCH v2 0/5] add quartz load support to NXP rtc drivers

From: Sam Ravnborg
Date: Tue Jan 08 2019 - 13:54:39 EST


pcf8523 hardcode the quartz load to 12.5pF
pcf85063 uses the reset default of 7pF

Introduce a new generic property "quartz-load-femtofarad"
to specify the quartz load.
The default value is selected to match the current Linux
drivers, so there are no behavior changes if a binding do not
specify the quarts-load.
The unit is femtofarads because several RTC's define the quarts load
in steps of 0.5 pF.

The two drivers rtc-pcf8523 and rtc-pcf85063 are both
updated to use the new binding.
The fix is tested on a proprietary board for both
RTC variants.

v2:
- Introduce a generic property "quartz-load-femtofarads"
- Add femtofarads to property-units.txt
- Make the changes backward compatible
- Reduced logging
- Warn, when we continue with a default value
- Tested, by SÃren Andersen, on real HW
- Rebased on top of v5.0-rc1

Sam

Sam Ravnborg (5):
devicetree: property-units: Add femtofarads unit
dt-binding: pcf8523: add xtal load capacitance
dt-binding: pcf85063: add xtal load capacitance
rtc: pcf8523: set xtal load capacitance from DT
rtc: pcf85063: set xtal load capacitance from DT

.../devicetree/bindings/property-units.txt | 1 +
.../devicetree/bindings/rtc/nxp,pcf85063.txt | 18 ++++++++++
.../devicetree/bindings/rtc/nxp,pcf8523.txt | 18 ++++++++++
Documentation/devicetree/bindings/rtc/rtc.txt | 2 --
drivers/rtc/rtc-pcf85063.c | 39 ++++++++++++++++++++++
drivers/rtc/rtc-pcf8523.c | 28 +++++++++++-----
6 files changed, 96 insertions(+), 10 deletions(-)