[PATCH v3 0/6] add quartz load support to NXP rtc drivers

From: Sam Ravnborg
Date: Sat Jan 19 2019 - 04:01:13 EST


Respin of patchset on top of v5.0-rc2 with feedback addressed (thanks!)

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.
Previously pcf8523 hardcoded the quartz load to 12.5pF, and
pcf85063 used the reset default of 7pF.
With this patchset it can now be specified in the DT,
if the defaults are not OK.

The patch-set is tested on a proprietary board for both
RTC variants (v2 variant only as there was only trivial changes in v3).

Sam

v3:
- Document generic property "quartz-load-femtofarads" in rtc.txt (Rob)
- Fix indent several places - ups (Alexandre)
- Use the simpler name "rtc" in DT examples (Rob)
- Collected "Reviewed by's"

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 (6):
devicetree: property-units: Add femtofarads unit
dt-bindings: rtc: Add quartz-load-femtofarads property
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 | 18 +++++-----
drivers/rtc/rtc-pcf85063.c | 39 ++++++++++++++++++++++
drivers/rtc/rtc-pcf8523.c | 28 +++++++++++-----
6 files changed, 106 insertions(+), 16 deletions(-)