On 16.03.2022 01:38, Robin Murphy wrote: > On 2022-02-25 21:09, Heiner Kallweit wrote: >> This series adds support for the Titanmec TM1628 7 segment display >> controller. It's based on previous RFC work from Andreas Färber. >> The RFC version placed the driver in the LED subsystem, but this was >> NAK'ed by the LED maintainer. Therefore I moved the driver to >> /drivers/auxdisplay what seems most reasonable to me. >> >> Further changes to the RFC version: >> - Driver can be built also w/o LED class support, for displays that >> don't have any symbols to be exposed as LED's. >> - Simplified the code and rewrote a lot of it. >> - Driver is now kind of a MVP, but functionality should be sufficient >> for most use cases. >> - Use the existing 7 segment support in uapi/linux/map_to_7segment.h >> as suggested by Geert Uytterhoeven. >> >> Note: There's a number of chips from other manufacturers that are >> almost identical, e.g. FD628, SM1628. Only difference I saw so >> far is that they partially support other display modes. >> TM1628: 6x12, 7x11 >> SM1628C: 4x13, 5x12, 6x11, 7x10 >> For typical displays on devices using these chips this >> difference shouldn't matter. >> >> Successfully tested on a TX3 Mini TV box that has an SM1628C and a >> display with 4 digits and 7 symbols. > > FWIW I gave this a go on my Beelink A1, which has an AiP1618 and a clock display which would mapped like so: > > titanmec,segment-mapping = /bits/ 8 <1 2 3 13 12 5 4>; > titanmec,grid = /bits/ 8 <5 4 2 1>; > > (grid 3 segment 2 is used for a colon in the middle) > > If I bodge around the lack of support for non-contiguous grids, it does otherwise work fairly well, other than being 6-segment displays because it needs to be in display mode 1 to drive SEG13 rather than GRID6. I wonder if we could be a bit cleverer about picking a display mode based on the grid/segment numbers used? > Definitely this could be one future extension. It could also consider that there's a number of more or less identical chips from other vendors that differ primarily in the supported display modes. > I also have a couple of those TM1638 breakout boards with 8 digits, 8 single LEDs and 8 buttons that I might have a go with too. Have you given any thought to how the DT binding might support inputs as well? (The best time to be future-proof is before it's merged...) > With regards to inputs at least I have no plans because I have no hw supporting input. Since the first attempts to support this LED driver hw two years have been passed w/o any tangible (mainline) result. Therefore I want to keep the initial version a MVP. Wanting to have too many features in an initial version may result in longer discussions until maintainer or I give up. Important is that user space interface / DT bindings are flexible enough so that future extensions don't have to break existing users. And I think that's the case. > Cheers, > Robin. > Heiner >> v2: >> - (re-)add Andreas' SoB to two patches >> - fix YAML issues >> - include ctype.h explicitly >> - add info message in probe() >> >> v3: >> - remove patch 1 because it has been applied via the SPI tree already >> - fix remaining YAML issues in patch 2 >> - follow Miguel's suggestion on usage of Co-Developed-by >> >> v4: >> - add patch for MAINTAINERS entry >> - incorporate Miguel's review comments >> - Replace Co-Developed-by with Co-developed-by (checkpatch) >> v5: >> - add vendor prefix to driver-specific dt properties >> >> Andreas Färber (1): >> dt-bindings: vendor-prefixes: Add Titan Micro Electronics >> >> Heiner Kallweit (5): >> dt-bindings: auxdisplay: Add Titan Micro Electronics TM1628 >> docs: ABI: document tm1628 attribute display-text >> auxdisplay: add support for Titanmec TM1628 7 segment display >> controller >> arm64: dts: meson-gxl-s905w-tx3-mini: add support for the 7 segment >> display >> MAINTAINERS: Add entry for tm1628 auxdisplay driver >> >> .../testing/sysfs-devices-auxdisplay-tm1628 | 7 + >> .../bindings/auxdisplay/titanmec,tm1628.yaml | 92 +++++ >> .../devicetree/bindings/vendor-prefixes.yaml | 2 + >> MAINTAINERS | 7 + >> .../dts/amlogic/meson-gxl-s905w-tx3-mini.dts | 59 +++ >> drivers/auxdisplay/Kconfig | 11 + >> drivers/auxdisplay/Makefile | 1 + >> drivers/auxdisplay/tm1628.c | 376 ++++++++++++++++++ >> 8 files changed, 555 insertions(+) >> create mode 100644 Documentation/ABI/testing/sysfs-devices-auxdisplay-tm1628 >> create mode 100644 Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml >> create mode 100644 drivers/auxdisplay/tm1628.c >>
