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- Status LED
- ========================================
- This README describes the status LED API.
- The API is defined by the include file include/status_led.h
- The first step is to enable CONFIG_LED_STATUS in menuconfig:
- > Device Drivers > LED Support.
- If the LED support is only for specific board, enable
- CONFIG_LED_STATUS_BOARD_SPECIFIC in the menuconfig.
- Status LEDS 0 to 5 are enabled by the following configurations at menuconfig:
- CONFIG_STATUS_LED0, CONFIG_STATUS_LED1, ... CONFIG_STATUS_LED5
- The following should be configured for each of the enabled LEDs:
- CONFIG_STATUS_LED_BIT<n>
- CONFIG_STATUS_LED_STATE<n>
- CONFIG_STATUS_LED_FREQ<n>
- Where <n> is an integer 1 through 5 (empty for 0).
- CONFIG_STATUS_LED_BIT is passed into the __led_* functions to identify which LED
- is being acted on. As such, the value choose must be unique with with respect to
- the other CONFIG_STATUS_LED_BIT's. Mapping the value to a physical LED is the
- reponsiblity of the __led_* function.
- CONFIG_STATUS_LED_STATE is the initial state of the LED. It should be set to one
- of these values: CONFIG_LED_STATUS_OFF or CONFIG_LED_STATUS_ON.
- CONFIG_STATUS_LED_FREQ determines the LED blink frequency.
- Values range from 2 to 10.
- Some other LED macros
- ---------------------
- CONFIG_STATUS_LED_BOOT is the LED to light when the board is booting.
- This must be a valid LED number (0-5).
- CONFIG_STATUS_LED_RED is the red LED. It is used to signal errors. This must be
- a valid LED number (0-5). Other similar color LED's macros are
- CONFIG_STATUS_LED_GREEN, CONFIG_STATUS_LED_YELLOW and CONFIG_STATUS_LED_BLUE.
- General LED functions
- ---------------------
- The following functions should be defined:
- __led_init is called once to initialize the LED to CONFIG_STATUS_LED_STATE.
- One time start up code should be placed here.
- __led_set is called to change the state of the LED.
- __led_toggle is called to toggle the current state of the LED.
- Colour LED
- ========================================
- Colour LED's are at present only used by ARM.
- The functions names explain their purpose.
- coloured_LED_init
- red_LED_on
- red_LED_off
- green_LED_on
- green_LED_off
- yellow_LED_on
- yellow_LED_off
- blue_LED_on
- blue_LED_off
- These are weakly defined in arch/arm/lib/board.c to noops. Where applicable, define
- these functions in the board specific source.
- TBD : Describe older board dependent macros similar to what is done for
- TBD : Describe general support via asm/status_led.h
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