raspberrypi-4b/i2c: Support for NOSTOP/NOSTART flags and better examples#19181
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raspberrypi-4b/i2c: Support for NOSTOP/NOSTART flags and better examples#19181linguini1 wants to merge 4 commits into
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This commit adds support for I2C transfers spread across multiple messages using the I2C_M_NOSTOP/I2C_M_NOSTART. The approach greedily merges as many sequential I2C messages together as possible and considers them as a single transfer. Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
Change the I2C character device registration to depend on the correct CONFIG option for enabling character drivers. Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
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Includes a new I2C configuration (and documentation for it) to use the I2C1 bus on the Raspberry Pi 4B. Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
This commit includes BMP280 driver registration on I2C1 in the RPi4B bringup logic _if_ the user selects the board-level configuration option (so as to not interfere with any user's custom implementation of interfacing with this sensor). A configuration is added with the BMP280 registration, example program and `uorb_listener` that is also documented. Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
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Summary
List of patches:
raspberrypi-4b/bmp280: Include optional registration of BMP280 driver
This commit includes BMP280 driver registration on I2C1 in the RPi4B
bringup logic if the user selects the board-level configuration option
(so as to not interfere with any user's custom implementation of
interfacing with this sensor). A configuration is added with the BMP280
registration, example program and
uorb_listenerthat is alsodocumented.
raspberrypi-4b/i2c: Added I2C configuration
Includes a new I2C configuration (and documentation for it) to use the
I2C1 bus on the Raspberry Pi 4B.
rpi4b/bringup: Use correct CONFIG option for I2C char driver
Change the I2C character device registration to depend on the correct
CONFIG option for enabling character drivers.
bcm2711/i2c: Support I2C_M_NOSTOP/I2C_M_NOSTART properly
This commit adds support for I2C transfers spread across multiple
messages using the I2C_M_NOSTOP/I2C_M_NOSTART. The approach greedily
merges as many sequential I2C messages together as possible and
considers them as a single transfer.
Related issues
This is part of the GSoC project #18507; milestone 1 item 1 (I2C improvement).
Impact
BCM2711 I2C driver is improved to support flags required for many I2C
devices, as per the discussion in [FEATURE] Complete RPi 4B I2C driver #16937.
An I2C configuration for the most commonly used bus (I2C1) is provided with
the
i2ctoolfor users to play with.A BMP280 configuration is supplied for users to play with a breakout board if
they wish.
Testing
I tested using the
raspberrypi-4b:bmp280configuration supplied in this patch.It includes all the functionality of
raspberrypi-4b:i2c1and tests the I2Clogic patch for supporting NO_STOP/NO_START flags. Here is the output of the
bmp280 program being run on the device:
And the I2C scanner:
Everything works as expected.