|This README describes the status LED API.
|The API is defined by the include file include/status_led.h
|The first step is to define CONFIG_STATUS_LED in the board config file.
|If the LED support is only for a single board, define CONFIG_BOARD_SPECIFIC_LED
|in the board config file.
|At a minimum, these macros must be defined at
|If there are multiple status LED's define
|Where <n> can a integer 1 through 3.
|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 STATUS_LED_BIT's. Mapping the value to a physical LED is the
|reponsiblity of the __led_* function.
|STATUS_LED_STATE is the initial state of the LED. It should be set to one of
|these values: STATUS_LED_OFF or STATUS_LED_ON.
|STATUS_LED_PERIOD is how long is the LED blink period. This usually set to
|(CONFIG_SYS_HZ / <N>) where <N> is the frequency of the blink. Typical values
|range from 2 to 10.
|Some other LED macros
|STATUS_LED_BOOT is the LED to light when the board is booting. This must be a
|valid STATUS_LED_BIT value.
|STATUS_LED_RED is the red LED. It is used signal errors. This must be a valid
|STATUS_LED_BIT value. Other similar color LED's are STATUS_LED_YELLOW and
|These board must define these functions
|__led_init is called once to initialize the LED to 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's are at present only used by ARM.
|The functions names explain their purpose.
|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