aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/arm/Sharp-LH/LCDPanels
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/arm/Sharp-LH/LCDPanels')
-rw-r--r--Documentation/arm/Sharp-LH/LCDPanels59
1 files changed, 59 insertions, 0 deletions
diff --git a/Documentation/arm/Sharp-LH/LCDPanels b/Documentation/arm/Sharp-LH/LCDPanels
new file mode 100644
index 000000000000..fb1b21c2f2f4
--- /dev/null
+++ b/Documentation/arm/Sharp-LH/LCDPanels
@@ -0,0 +1,59 @@
1README on the LCD Panels
2========================
3
4Configuration options for several LCD panels, available from Logic PD,
5are included in the kernel source. This README will help you
6understand the configuration data and give you some guidance for
7adding support for other panels if you wish.
8
9
10lcd-panels.h
11------------
12
13There is no way, at present, to detect which panel is attached to the
14system at runtime. Thus the kernel configuration is static. The file
15arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the
16panel specific parameters.
17
18It should be possible for this data to be shared among several device
19families. The current layout may be insufficiently general, but it is
20amenable to improvement.
21
22
23PIXEL_CLOCK
24-----------
25
26The panel data sheets will give a range of acceptable pixel clocks.
27The fundamental LCDCLK input frequency is divided down by a PCD
28constant in field '.tim2'. It may happen that it is impossible to set
29the pixel clock within this range. A clock which is too slow will
30tend to flicker. For the highest quality image, set the clock as high
31as possible.
32
33
34MARGINS
35-------
36
37These values may be difficult to glean from the panel data sheet. In
38the case of the Sharp panels, the upper margin is explicitly called
39out as a specific number of lines from the top of the frame. The
40other values may not matter as much as the panels tend to
41automatically center the image.
42
43
44Sync Sense
45----------
46
47The sense of the hsync and vsync pulses may be called out in the data
48sheet. On one panel, the sense of these pulses determine the height
49of the visible region on the panel. Most of the Sharp panels use
50negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in
51'.tim2'.
52
53
54Pel Layout
55----------
56
57The Sharp color TFT panels are all configured for 16 bit direct color
58modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of
59each red and blue and 6 bits of green.