Re: [PATCH] video: ARM CLCD: Added dt support to set tim2 register

From: Arun Ramamurthy
Date: Mon Mar 02 2015 - 14:10:36 EST

On 15-03-02 08:11 AM, Pawel Moll wrote:
On Wed, 2015-02-25 at 21:01 +0000, Arun Ramamurthy wrote:
Added code based on linaro tree:
with commit id:6846e7822c4cab5a84672baace3b768c2d0db142
at drivers/video/amba-clcd.c. This lets the driver set
certain tim2 register bits after reading them from
device tree.

Reviewed-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
Signed-off-by: Arun Ramamurthy <arun.ramamurthy@xxxxxxxxxxxx>
.../devicetree/bindings/video/arm,pl11x.txt | 17 ++++++++-
drivers/video/fbdev/amba-clcd.c | 41 ++++++++++++++++++++++
2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/video/arm,pl11x.txt b/Documentation/devicetree/bindings/video/arm,pl11x.txt
index 3e3039a..14d6f87 100644
--- a/Documentation/devicetree/bindings/video/arm,pl11x.txt
+++ b/Documentation/devicetree/bindings/video/arm,pl11x.txt
@@ -35,6 +35,21 @@ Optional properties:
cell's memory interface can handle; if not present, the memory
interface is fast enough to handle all possible video modes

+- tim2: Used to set certain bits in LCDTiming2 register.
+ It can be TIM2_CLKSEL or TIM2_IOE or both
+ TIM2_CLKSEL: This bit drives the CLCDCLKSEL signal. It is the select
+ signal for the external LCD clock multiplexor.
+ TIM2_IOE: Invert output enable:
+ 0 = CLAC output pin is active HIGH in TFT mode
+ 1 = CLAC output pin is active LOW in TFT mode.
+ This bit selects the active polarity of the output enable signal in
+ TFT mode. In this mode, the CLAC pin is an enable that indicates to
+ the LCD panel when valid display data is available. In active
+ display mode, data is driven onto the LCD data lines at the
+ programmed edge of CLCP when CLAC is in its active state.

The existing bindings intentionally avoided quoting internal registers -
they are supposed to describe how the hardware is wired up...

So how about something like "arm,pl11x,tft-invert-clac"? Then the driver
sets the bit or not, depending on the property existance?

Sure, I can change it to two properties called arm,pl11x,tft-invert-clac and arm,pl11x,tft-clksel. Would that be acceptable?


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