[PATCH v3 1/2] video: ARM CLCD: Add DT support

On 09/18/2013 10:39 AM, Pawel Moll wrote:

On Tue, 2013-09-17 at 22:34 +0100, Stephen Warren wrote:

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On Tue, 2013-09-17 at 17:36 +0100, Pawel Moll wrote:

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On Mon, 2013-09-16 at 20:52 +0100, Stephen Warren wrote:

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+- arm,pl11x,panel-data-pads: array of 24 cells, each of them describing
+				a function of one of the CLD pads,
+				starting from 0 up to 23; each pad can
+				be described by one of the following values:
+	- 0: reserved (not connected)
+	- 0x100-0x107: color upper STN panel data 0 to 7

...

I assume those are the raw values that go into the HW?

No, they can be considered "labels", defining the way pads are used
(wired). Then, basing on this information, the driver is configuring the
cell, eg. selecting STN or TFT mode (thus switching the output between
panel formatter and raw RGB data source).

Oh, why not just use the raw values from the HW registers for this?

How do you mean? Based on the the way the "LCD data" lines are wired up,
the driver has to decide whether to select STN (LCDControl &= ~(1<<5))
or TFT mode (LCDControl |= 1<<5), then figures out what memory pixel
formats are possible (based on this will set LCDControl[3..1] in
runtime, depending on the mode selected by the user). There isn't a
separate register as such configuring output pads. It's just the way
they can used depends on the way they're wired up.

It sounds like you could just put LCDControl & 0x2e in the DT rather
than using values such as 0x100..0x107, which don't appear to match the
register format you mentioned above.