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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 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
- STATUS_LED_BIT
- STATUS_LED_STATE
- STATUS_LED_PERIOD
- If there are multiple status LED's define
- STATUS_LED_BIT<n>
- STATUS_LED_STATE<n>
- STATUS_LED_PERIOD<n>
- 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
- STATUS_LED_BLUE.
- 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
- ========================================
- 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 lib_arm/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
- CONFIG_TQM8xxL.
- TBD : Describe general support via asm/status_led.h
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