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Diffstat (limited to 'qemu/roms/u-boot/doc/README.LED_display')
| -rw-r--r-- | qemu/roms/u-boot/doc/README.LED_display | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/qemu/roms/u-boot/doc/README.LED_display b/qemu/roms/u-boot/doc/README.LED_display new file mode 100644 index 000000000..19977ea7e --- /dev/null +++ b/qemu/roms/u-boot/doc/README.LED_display @@ -0,0 +1,26 @@ +LED display internal API +======================================= + +This README describes the LED display API. + +The API is defined by the include file include/led-display.h + +The first step in to define CONFIG_CMD_DISPLAY in the board config file. +Then you need to provide the following functions to access LED display: + +void display_set(int cmd); + +This function should control the state of the LED display. Argument is +an ORed combination of the following values: + DISPLAY_CLEAR -- clear the display + DISPLAY_HOME -- set the position to the beginning of display + +int display_putc(char c); + +This function should display it's parameter on the LED display in the +current position. Returns the displayed character on success or -1 in +case of failure. + +With this functions defined 'display' command will display it's +arguments on the LED display (or clear the display if called without +arguments). |