1Status LED 2======================================== 3 4This README describes the status LED API. 5 6The API is defined by the include file include/status_led.h 7 8The first step is to enable CONFIG_LED_STATUS in menuconfig: 9> Device Drivers > LED Support. 10 11If the LED support is only for specific board, enable 12CONFIG_LED_STATUS_BOARD_SPECIFIC in the menuconfig. 13 14Status LEDS 0 to 5 are enabled by the following configurations at menuconfig: 15CONFIG_STATUS_LED0, CONFIG_STATUS_LED1, ... CONFIG_STATUS_LED5 16 17The following should be configured for each of the enabled LEDs: 18CONFIG_STATUS_LED_BIT<n> 19CONFIG_STATUS_LED_STATE<n> 20CONFIG_STATUS_LED_FREQ<n> 21Where <n> is an integer 1 through 5 (empty for 0). 22 23CONFIG_STATUS_LED_BIT is passed into the __led_* functions to identify which LED 24is being acted on. As such, the value choose must be unique with with respect to 25the other CONFIG_STATUS_LED_BIT's. Mapping the value to a physical LED is the 26reponsiblity of the __led_* function. 27 28CONFIG_STATUS_LED_STATE is the initial state of the LED. It should be set to one 29of these values: CONFIG_LED_STATUS_OFF or CONFIG_LED_STATUS_ON. 30 31CONFIG_STATUS_LED_FREQ determines the LED blink frequency. 32Values range from 2 to 10. 33 34Some other LED macros 35--------------------- 36 37CONFIG_STATUS_LED_BOOT is the LED to light when the board is booting. 38This must be a valid LED number (0-5). 39 40CONFIG_STATUS_LED_RED is the red LED. It is used to signal errors. This must be 41a valid LED number (0-5). Other similar color LED's macros are 42CONFIG_STATUS_LED_GREEN, CONFIG_STATUS_LED_YELLOW and CONFIG_STATUS_LED_BLUE. 43 44General LED functions 45--------------------- 46The following functions should be defined: 47 48__led_init is called once to initialize the LED to CONFIG_STATUS_LED_STATE. 49One time start up code should be placed here. 50 51__led_set is called to change the state of the LED. 52 53__led_toggle is called to toggle the current state of the LED. 54 55Colour LED 56======================================== 57 58Colour LED's are at present only used by ARM. 59 60The functions names explain their purpose. 61 62coloured_LED_init 63red_LED_on 64red_LED_off 65green_LED_on 66green_LED_off 67yellow_LED_on 68yellow_LED_off 69blue_LED_on 70blue_LED_off 71 72These are weakly defined in arch/arm/lib/board.c to noops. Where applicable, define 73these functions in the board specific source. 74 75TBD : Describe older board dependent macros similar to what is done for 76 77TBD : Describe general support via asm/status_led.h 78