xref: /OK3568_Linux_fs/u-boot/doc/README.LED_display (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunLED display internal API
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4*4882a593SmuzhiyunThis README describes the LED display API.
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6*4882a593SmuzhiyunThe API is defined by the include file include/led-display.h
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8*4882a593SmuzhiyunThe first step in to define CONFIG_CMD_DISPLAY in the board config file.
9*4882a593SmuzhiyunThen you need to provide the following functions to access LED display:
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11*4882a593Smuzhiyunvoid display_set(int cmd);
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13*4882a593SmuzhiyunThis function should control the state of the LED display. Argument is
14*4882a593Smuzhiyunan ORed combination of the following values:
15*4882a593Smuzhiyun DISPLAY_CLEAR	-- clear the display
16*4882a593Smuzhiyun DISPLAY_HOME	-- set the position to the beginning of display
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18*4882a593Smuzhiyunint display_putc(char c);
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20*4882a593SmuzhiyunThis function should display it's parameter on the LED display in the
21*4882a593Smuzhiyuncurrent position. Returns the displayed character on success or -1 in
22*4882a593Smuzhiyuncase of failure.
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24*4882a593SmuzhiyunWith this functions defined 'display' command will display it's
25*4882a593Smuzhiyunarguments on the LED display (or clear the display if called without
26*4882a593Smuzhiyunarguments).
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