Messages in this thread | | | From | Charles Mirabile <> | Subject | [PATCH V5 0/6] Raspberry Pi Sense HAT driver | Date | Fri, 10 Dec 2021 17:10:27 -0500 |
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This patch series adds a set of drivers for operating the Sense HAT peripheral device. This board is an add on for the Raspberry Pi that is designed to connect using the GPIO connector via I2C.
It features: - a joystick - an 8x8 RGB LED matrix display - a whole bunch of environmental sensors with their own drivers (those are already in upstream Linux)
This is a refactor of the work of Serge Schneider, the author of a version of this driver that is currently in the Raspberry Pi downstream kernel. We modified his code to make it suitable for upstream Linux.
A couple of tests are available for the driver in this repo: https://github.com/underground-software/sensehat/tree/master/tests - color_test displays various solid colors on the LED panel - framebuffer_test displays a single lit cell that is controllable via the arrow keys or the joystick
For more information about the Sense HAT, visit: https://www.raspberrypi.org/products/sense-hat/
Issues fixed since v4: - Removed the regmap readable/writeable register functions because they necessitated putting lots of internal details in the header. Moved those details back into .c files (Thanks to Matthias Brugger for the suggestion). - Added ifdef blocks to only attempt to register the children devices the user wants according to kconfig (Thanks to Thomas Weißschuh for the suggestion). - Corrected kconfig dependencies for joystick and display so that they now also depend on i2c being enabled (Thanks to Randy Dunlap for the suggestion). - Simplified the control flow in display ioctl (Thanks to Matthias Brugger for the suggestion). - Signed off on the patch sets correctly with co-developed-by (Thanks to Miguel Ojeda for the correction).
Improvements since v4: - Removed fallback compatible string from downstream overlay and having dropped support for it, wrote a new overlay and binding that uses the interrupt and interrupt-parent properties as opposed to a downstream hack, thus simplifying the registration logic for joystick (Thanks to Rob Herring for the suggestion).
Suggestions from v4 not addressed yet: - Use mfd_cells for the joystick and display platform devices (as suggested by Matthias Brugger) or remove sensehat-core.c entirely and use simple-mfd-i2c instead (as suggested by Nicolás Sáenz Julienne). - while these suggestions might make great improvements for a version two of the driver they would require a large rewrite to move all of the complexity in core elsewhere. While certainly possible and something we want to iterate on and achieve eventually, we think saving it for down the road makes sense at this time. - Modify the userspace interface of the display driver so it matches the internal representation used by the uC on the other end of the wire to try and eliminate the overhead of reformatting it. - The format is still compatible with the downstream version of this driver meaning that porting existing applications for the sensehat to work with this driver is currently trivial. Changing this interface would make it less so. Although certainly not impossible, it is a downside to be considered. - The "complexity" of unpacking the bit packed the data is a current cost, but it has the added benefit of automatically restricting the values to 0-31. New logic would need to be added to clamp or wrap out of bounds values that might be just as expensive.
Signed-off-by: Charles Mirabile <cmirabil@redhat.com> Co-developed-by: Mwesigwa Guma <mguma@redhat.com> Signed-off-by: Mwesigwa Guma <mguma@redhat.com> Co-developed-by: Joel Savitz <jsavitz@redhat.com> Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Charles Mirabile (6): drivers/mfd: sensehat: Raspberry Pi Sense HAT core driver drivers/input/joystick: sensehat: Raspberry Pi Sense HAT joystick driver drivers/auxdisplay: sensehat: Raspberry Pi Sense HAT display driver dt-bindings: mfd: sensehat: Raspberry Pi Sense HAT schema MAINTAINERS: Add sensehat driver authors to MAINTAINERS DO NOT MERGE: full sensehat device tree overlay for raspberry pi 4
.../bindings/mfd/raspberrypi,sensehat.yaml | 54 ++++ MAINTAINERS | 11 + drivers/auxdisplay/Kconfig | 8 + drivers/auxdisplay/Makefile | 1 + drivers/auxdisplay/sensehat-display.c | 268 ++++++++++++++++++ drivers/input/joystick/Kconfig | 8 + drivers/input/joystick/Makefile | 1 + drivers/input/joystick/sensehat-joystick.c | 119 ++++++++ drivers/mfd/Kconfig | 8 + drivers/mfd/Makefile | 1 + drivers/mfd/sensehat-core.c | 157 ++++++++++ include/linux/mfd/sensehat.h | 51 ++++ sensehat.dtbs | 44 +++ 13 files changed, 731 insertions(+) create mode 100644 Documentation/devicetree/bindings/mfd/raspberrypi,sensehat.yaml create mode 100644 drivers/auxdisplay/sensehat-display.c create mode 100644 drivers/input/joystick/sensehat-joystick.c create mode 100644 drivers/mfd/sensehat-core.c create mode 100644 include/linux/mfd/sensehat.h create mode 100644 sensehat.dtbs
-- 2.31.1
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