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author | fishsoupisgood <github@madingley.org> | 2019-04-29 01:17:54 +0100 |
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committer | fishsoupisgood <github@madingley.org> | 2019-05-27 03:43:43 +0100 |
commit | 3f2546b2ef55b661fd8dd69682b38992225e86f6 (patch) | |
tree | 65ca85f13617aee1dce474596800950f266a456c /roms/u-boot/doc/README.LED_display | |
download | qemu-master.tar.gz qemu-master.tar.bz2 qemu-master.zip |
Diffstat (limited to 'roms/u-boot/doc/README.LED_display')
-rw-r--r-- | roms/u-boot/doc/README.LED_display | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/roms/u-boot/doc/README.LED_display b/roms/u-boot/doc/README.LED_display new file mode 100644 index 00000000..19977ea7 --- /dev/null +++ b/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). |