Rob Herring <robh+dt@xxxxxxxxxx> writes: > On Mon, May 15, 2017 at 7:03 PM, Eric Anholt <eric@xxxxxxxxxx> wrote: >> Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> writes: >> >>> Hi Eric, >>> >>> Thank you for the patch. >>> >>> On Thursday 11 May 2017 16:56:23 Eric Anholt wrote: >>>> The Raspberry Pi 7" Touchscreen is a DPI touchscreen panel with >>>> DSI->DPI bridge and touchscreen controller integrated, that connects >>>> to the Raspberry Pi through its 15-pin "DSI" connector (some lines are >>>> DSI, some lines are I2C). >>>> >>>> This device is represented in the DT as three nodes (DSI device, I2C >>>> device, panel). Input will be left to a separate binding later, as it >>>> will be a basic I2C client device. >>>> >>>> Signed-off-by: Eric Anholt <eric@xxxxxxxxxx> >>>> --- >>>> .../raspberrypi,7inch-touchscreen-bridge.txt | 68 +++++++++++++++++++ >>>> .../panel/raspberrypi,7inch-touchscreen-panel.txt | 7 +++ >>>> 2 files changed, 75 insertions(+) >>>> create mode 100644 >>>> Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchscr >>>> een-bridge.txt create mode 100644 >>>> Documentation/devicetree/bindings/display/panel/raspberrypi,7inch-touchscre >>>> en-panel.txt >>>> >>>> diff --git >>>> a/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt new file mode 100644 >>>> index 000000000000..a5669beaf68f >>>> --- /dev/null >>>> +++ >>>> b/Documentation/devicetree/bindings/display/bridge/raspberrypi,7inch-touchs >>>> creen-bridge.txt @@ -0,0 +1,68 @@ >>>> +Official 7" (800x480) Raspberry Pi touchscreen panel's bridge. >>>> + >>>> +This DSI panel contains: >>>> + >>>> +- TC358762 DSI->DPI bridge >>>> +- Atmel microcontroller on I2C for power sequencing the DSI bridge and >>>> + controlling backlight >>>> +- Touchscreen controller on I2C for touch input >>>> + >>>> +and this covers the TC358762 bridge and Atmel microcontroller, while >>>> +../panel/raspberrypi,7inch-touchscreen-panel.txt covers the panel. >>> >>> The TC358762 is a standalone bridge that doesn't depend on the ATTiny >>> microcontroller used by the RPI. As it's usable standalone, I believe this >>> binding should be split in two. >> >> Do you have a plan for how I would implement a driver on top of that >> binding change, though? Note that we don't program the Toshiba >> directly, we only send commands to the Atmel. > > I agree. If it is a black box and the interface to the host is defined > by the Atmel uC firmware, then that's what the DT should describe. > Perhaps a diagram here or pointer to one would help and remove > mentioning what kind of bridge chip it is. It's a *very* black box. I have some non-public schematics that don't even say what panel is involved, and no documentation of the uc interface. The driver code is just replicating the firmware's programming sequence. I would certainly love to be building a generic TC358762 driver, which would be a lot more satisfying. I just don't think it's doable for this panel. Given that, what do I need to do to the DT? Should I just drop mention of the Toshiba and talk about this being a bridge with a custom microcontroller firmware?
Attachment:
signature.asc
Description: PGP signature
