| 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. |