diff options
| author | Heiner Kallweit <hkallweit1@gmail.com> | 2023-01-18 22:55:12 +0100 |
|---|---|---|
| committer | Wolfram Sang <wsa@kernel.org> | 2023-01-23 23:18:54 +0100 |
| commit | 8786b095df02c1b881643146869a7d6f80411e6a (patch) | |
| tree | 541f37aca6742f571b6bb44098818675c916d984 /include/linux/platform_data/i2c-gpio.h | |
| parent | 9dfee1487c271b7904e38dea5bed8f6e2d058dc3 (diff) | |
i2c: gpio: support write-only sda/scl w/o pull-up
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.
Handle the new attributes for write-only SDA and missing pull-up on
SDA/SCL.
For either pin the open-drain and has-no-pullup properties are
mutually-exclusive, what is documented in the DT property documentation.
We don't add an extra warning here because the open-drain properties
are marked deprecated anyway.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
[wsa: switched to device properties]
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Diffstat (limited to 'include/linux/platform_data/i2c-gpio.h')
| -rw-r--r-- | include/linux/platform_data/i2c-gpio.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/linux/platform_data/i2c-gpio.h b/include/linux/platform_data/i2c-gpio.h index a907774fd177..545639bcca72 100644 --- a/include/linux/platform_data/i2c-gpio.h +++ b/include/linux/platform_data/i2c-gpio.h @@ -16,16 +16,25 @@ * isn't actively driven high when setting the output value high. * gpio_get_value() must return the actual pin state even if the * pin is configured as an output. + * @sda_is_output_only: SDA output drivers can't be turned off. + * This is for clients that can only read SDA/SCL. + * @sda_has_no_pullup: SDA is used in a non-compliant way and has no pull-up. + * Therefore disable open-drain. * @scl_is_open_drain: SCL is set up as open drain. Same requirements * as for sda_is_open_drain apply. * @scl_is_output_only: SCL output drivers cannot be turned off. + * @scl_has_no_pullup: SCL is used in a non-compliant way and has no pull-up. + * Therefore disable open-drain. */ struct i2c_gpio_platform_data { int udelay; int timeout; unsigned int sda_is_open_drain:1; + unsigned int sda_is_output_only:1; + unsigned int sda_has_no_pullup:1; unsigned int scl_is_open_drain:1; unsigned int scl_is_output_only:1; + unsigned int scl_has_no_pullup:1; }; #endif /* _LINUX_I2C_GPIO_H */ |