[PATCH 0/7] rtc: m41t93: add new features alarm, clock out, watchdog

[Akhilesh Patil <akhilesh@ee.iitb.ac.in>]

This patch series adds following to m41t93 rtc driver.

Functionalities: 
- Alarm support (support to configure alarm 1)
- Square wave output support
- Watchdog support

Code improvements:
this series migrates existing driver to use standard regmap interface
for spi instead of direct spi calls and uses regmap for new features.

Bug fix: 
Fixes device probe issue after power-on due to incorrect assumptions of
reset values of the registers.

Device tree support:
Adds device tree support to the driver along with binding documentation.

Testing:
This patch series is validated on TI am62x board with m41t93 rtc chip
connected to spi0 bus.
regmap migration is additionally tested by observing spi transfers
with the help of logic analyzer. Short summary of test flow is added in
commit message of respective features.

Datasheet:
https://www.st.com/resource/en/datasheet/m41t93.pdf

patch 4 to 7 depend on patch 3 (regmap patch)

Regards,
Akhilesh

Akhilesh Patil (7):
  rtc: m41t93: add device tree support
  dt-bindings: rtc: add bindings for m41t93
  rtc: m41t93: migrate to regmap api for register access
  rtc: m41t93: Add alarm support
  rtc: m41t93: fix device connection/detection logic during probe
  rtc: m41t93: Add square wave clock provider support
  rtc: m41t93: Add watchdog support

 .../devicetree/bindings/rtc/st,m41t93.yaml    |  43 ++
 drivers/rtc/rtc-m41t93.c                      | 489 ++++++++++++++++--
 2 files changed, 479 insertions(+), 53 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/rtc/st,m41t93.yaml

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2.34.1