From 51cb21a9cd2e3bba8a69948794eb9480facdef45 Mon Sep 17 00:00:00 2001 From: Marc Singer Date: Tue, 16 May 2006 11:41:43 +0100 Subject: [ARM] 3407/1: lpd7x: documetation update Patch from Marc Singer New documentation for the touchscreen controllers and LCD panels. Signed-off-by: Marc Singer Signed-off-by: Russell King --- Documentation/arm/Sharp-LH/LCDPanels | 59 ++++++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 Documentation/arm/Sharp-LH/LCDPanels (limited to 'Documentation/arm/Sharp-LH/LCDPanels') diff --git a/Documentation/arm/Sharp-LH/LCDPanels b/Documentation/arm/Sharp-LH/LCDPanels new file mode 100644 index 00000000000..fb1b21c2f2f --- /dev/null +++ b/Documentation/arm/Sharp-LH/LCDPanels @@ -0,0 +1,59 @@ +README on the LCD Panels +======================== + +Configuration options for several LCD panels, available from Logic PD, +are included in the kernel source. This README will help you +understand the configuration data and give you some guidance for +adding support for other panels if you wish. + + +lcd-panels.h +------------ + +There is no way, at present, to detect which panel is attached to the +system at runtime. Thus the kernel configuration is static. The file +arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the +panel specific parameters. + +It should be possible for this data to be shared among several device +families. The current layout may be insufficiently general, but it is +amenable to improvement. + + +PIXEL_CLOCK +----------- + +The panel data sheets will give a range of acceptable pixel clocks. +The fundamental LCDCLK input frequency is divided down by a PCD +constant in field '.tim2'. It may happen that it is impossible to set +the pixel clock within this range. A clock which is too slow will +tend to flicker. For the highest quality image, set the clock as high +as possible. + + +MARGINS +------- + +These values may be difficult to glean from the panel data sheet. In +the case of the Sharp panels, the upper margin is explicitly called +out as a specific number of lines from the top of the frame. The +other values may not matter as much as the panels tend to +automatically center the image. + + +Sync Sense +---------- + +The sense of the hsync and vsync pulses may be called out in the data +sheet. On one panel, the sense of these pulses determine the height +of the visible region on the panel. Most of the Sharp panels use +negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in +'.tim2'. + + +Pel Layout +---------- + +The Sharp color TFT panels are all configured for 16 bit direct color +modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of +each red and blue and 6 bits of green. -- cgit v1.2.3