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https://github.com/brain-hackers/u-boot-brain
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5b8e76c35e
There was for long time no activity in the 8xx area. We need to go further and convert to Kconfig, but it turned out, nobody is interested anymore in 8xx, so remove it (with a heavy heart, knowing that I remove here the root of U-Boot). Signed-off-by: Heiko Schocher <hs@denx.de>
78 lines
2.4 KiB
Plaintext
78 lines
2.4 KiB
Plaintext
Status LED
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========================================
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This README describes the status LED API.
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The API is defined by the include file include/status_led.h
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The first step is to enable CONFIG_LED_STATUS in menuconfig:
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> Device Drivers > LED Support.
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If the LED support is only for specific board, enable
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CONFIG_LED_STATUS_BOARD_SPECIFIC in the menuconfig.
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Status LEDS 0 to 5 are enabled by the following configurations at menuconfig:
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CONFIG_STATUS_LED0, CONFIG_STATUS_LED1, ... CONFIG_STATUS_LED5
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The following should be configured for each of the enabled LEDs:
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CONFIG_STATUS_LED_BIT<n>
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CONFIG_STATUS_LED_STATE<n>
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CONFIG_STATUS_LED_FREQ<n>
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Where <n> is an integer 1 through 5 (empty for 0).
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CONFIG_STATUS_LED_BIT is passed into the __led_* functions to identify which LED
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is being acted on. As such, the value choose must be unique with with respect to
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the other CONFIG_STATUS_LED_BIT's. Mapping the value to a physical LED is the
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reponsiblity of the __led_* function.
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CONFIG_STATUS_LED_STATE is the initial state of the LED. It should be set to one
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of these values: CONFIG_LED_STATUS_OFF or CONFIG_LED_STATUS_ON.
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CONFIG_STATUS_LED_FREQ determines the LED blink frequency.
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Values range from 2 to 10.
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Some other LED macros
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---------------------
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CONFIG_STATUS_LED_BOOT is the LED to light when the board is booting.
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This must be a valid LED number (0-5).
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CONFIG_STATUS_LED_RED is the red LED. It is used to signal errors. This must be
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a valid LED number (0-5). Other similar color LED's macros are
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CONFIG_STATUS_LED_GREEN, CONFIG_STATUS_LED_YELLOW and CONFIG_STATUS_LED_BLUE.
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General LED functions
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---------------------
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The following functions should be defined:
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__led_init is called once to initialize the LED to CONFIG_STATUS_LED_STATE.
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One time start up code should be placed here.
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__led_set is called to change the state of the LED.
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__led_toggle is called to toggle the current state of the LED.
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Colour LED
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========================================
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Colour LED's are at present only used by ARM.
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The functions names explain their purpose.
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coloured_LED_init
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red_LED_on
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red_LED_off
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green_LED_on
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green_LED_off
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yellow_LED_on
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yellow_LED_off
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blue_LED_on
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blue_LED_off
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These are weakly defined in arch/arm/lib/board.c to noops. Where applicable, define
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these functions in the board specific source.
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TBD : Describe older board dependent macros similar to what is done for
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TBD : Describe general support via asm/status_led.h
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