sensors: lis2dh: disable SDO/SA0 pull-up in case of LIS3DH #19624
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I'm fine with the commit that unconditionally builds the helper function.
As for the pull-up control we should be avoiding Kconfig as devicetree is the "way forward". For my suggested approach see below in context.
It would be nice to move the existing irq-gpios and proposed disconnect-sdo-sda0-pull-up into a new st,lis2dh-common.yaml file that is included by both the SPI and I2C variants.
Create a common binding file that will be included by all bindings handled by lis2dh.c driver. For now this includes optional irq-gpios property. Use introduced st,lis2dh-common.yaml in st,lsm303dlhc-accel.yaml in order to support defining irq-gpios. Also improve description of st,lis2dh-i2c.yaml to better match what can be found in st,lis2dh-spi.yaml. Signed-off-by: Marcin Niestroj <[email protected]>
There is little reason to compile lis2dh_reg_field_update() function conditionally, based on enabled features. If it is not used, then linker will drop it anyway. Signed-off-by: Marcin Niestroj <[email protected]>
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Based on the review comments I have introduced new device-tree property to disconnect SDO/SA0 pull-up when specified to be fully controlable by user. Hence previous logic based on compatible string has been dropped. Also a commit |
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Using IS_ENABLED(M) is standard for Kconfig and devicetree macros that have 0 or 1 as their value. It also evaluates to syntactically acceptable content when the macro definition is absent, as with frdm_k64f on test_build_sensors_i_z where there is no define for any LIS2DH devicetree entries. I think you should put it back which should fix the build problems.
Some chips supported by lis2dh driver (such as LIS2DH12 and LIS3DH) contain CTRL_REG0 (1Eh) register to control internal pull-up on SDO/SA0 line (enabled by default). Add disconnect-sdo-sa0-pull-up boolean device-tree property to allow disconnecting pull-up during driver initialization. This allows to save around 180uA at 3.6V in accelerometer power-down mode. Signed-off-by: Marcin Niestroj <[email protected]>
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LIS3DH contains CTRL_REG0 (1Eh) register to control internal pull-up on
SDO/SA0 line (enabled by default). Add a helper
LIS2DH_HAS_SDO_SA0_PULL_UP macro, which is defined only when "st,lis3dh"
was passed to compatible list in device-tree. Based on that macro
disable internal pull-up registers, which consume around 180uA at 3.6V
in accelerometer power-down mode.
Signed-off-by: Marcin Niestroj [email protected]