[PATCH v4 0/3] i2c: gpio: support write-only sda

[Heiner Kallweit <hkallweit1@gmail.com>]

There are slave devices that understand I2C but have read-only SDA and
SCL. Examples are FD650 7-segment LED controller and its derivatives.
Typical board designs don't even have a pull-up for both pins.
Therefore add properties for not using open-drain. For write-only SCL
we have a property already, add one for write-only SDA.

v2:
- improve commit message for patch 1

v3:
- patch 2: check for adap->getsda in readbytes()
- patch 2: align warning message level for info on missing getscl/getsda
- patch 3: improve description of attribute sda_is_output_only

v4:
- patch 1: add no-pullup properties
- patch 2: handle SDA and SCL independently
- patch 2: properly handle case that SDA is NULL but SCL not
- patch 3: handle new no-pullup attributes

Heiner Kallweit (3):
  dt-bindings: i2c-gpio: Add properties for dealing with write-only SDA/SCL w/o pullup
  i2c: algo: bit: allow getsda to be NULL
  i2c: gpio: support write-only sda/scl w/o pull-up

 .../devicetree/bindings/i2c/i2c-gpio.yaml     | 16 ++++
 drivers/i2c/algos/i2c-algo-bit.c              | 77 +++++++++----------
 drivers/i2c/busses/i2c-gpio.c                 | 13 +++-
 include/linux/platform_data/i2c-gpio.h        |  9 +++
 4 files changed, 70 insertions(+), 45 deletions(-)

-- 
2.39.0