projects / people / ms / u-boot.git / blame
| Commit | Line | Data |
|---|---|---|
| 65fd21c8 TR |
1 | Status LED |
| 2 | ======================================== | |
| 3 | ||
| 4 | This README describes the status LED API. | |
| 5 | ||
| 6 | The API is defined by the include file include/status_led.h | |
| 7 | ||
| 79267edd UM |
8 | The first step is to enable CONFIG_LED_STATUS in menuconfig: |
| 9 | > Device Drivers > LED Support. | |
| 65fd21c8 | 10 | |
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11 | If the LED support is only for specific board, enable |
| 12 | CONFIG_LED_STATUS_BOARD_SPECIFIC in the menuconfig. | |
| 65fd21c8 | 13 | |
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14 | Status LEDS 0 to 5 are enabled by the following configurations at menuconfig: |
| 15 | CONFIG_STATUS_LED0, CONFIG_STATUS_LED1, ... CONFIG_STATUS_LED5 | |
| 65fd21c8 | 16 | |
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17 | The following should be configured for each of the enabled LEDs: |
| 18 | CONFIG_STATUS_LED_BIT<n> | |
| 19 | CONFIG_STATUS_LED_STATE<n> | |
| 20 | CONFIG_STATUS_LED_FREQ<n> | |
| 21 | Where <n> is an integer 1 through 5 (empty for 0). | |
| 65fd21c8 | 22 | |
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23 | CONFIG_STATUS_LED_BIT is passed into the __led_* functions to identify which LED |
| 24 | is being acted on. As such, the value choose must be unique with with respect to | |
| 25 | the other CONFIG_STATUS_LED_BIT's. Mapping the value to a physical LED is the | |
| 65fd21c8 TR |
26 | reponsiblity of the __led_* function. |
| 27 | ||
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28 | CONFIG_STATUS_LED_STATE is the initial state of the LED. It should be set to one |
| 29 | of these values: CONFIG_LED_STATUS_OFF or CONFIG_LED_STATUS_ON. | |
| 65fd21c8 | 30 | |
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31 | CONFIG_STATUS_LED_FREQ determines the LED blink frequency. |
| 32 | Values range from 2 to 10. | |
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33 | |
| 34 | Some other LED macros | |
| 79267edd | 35 | --------------------- |
| 65fd21c8 | 36 | |
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37 | CONFIG_STATUS_LED_BOOT is the LED to light when the board is booting. |
| 38 | This must be a valid LED number (0-5). | |
| 65fd21c8 | 39 | |
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40 | CONFIG_STATUS_LED_RED is the red LED. It is used to signal errors. This must be |
| 41 | a valid LED number (0-5). Other similar color LED's macros are | |
| 42 | CONFIG_STATUS_LED_GREEN, CONFIG_STATUS_LED_YELLOW and CONFIG_STATUS_LED_BLUE. | |
| 65fd21c8 | 43 | |
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44 | General LED functions |
| 45 | --------------------- | |
| 46 | The following functions should be defined: | |
| 65fd21c8 | 47 | |
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48 | __led_init is called once to initialize the LED to CONFIG_STATUS_LED_STATE. |
| 49 | One time start up code should be placed here. | |
| 65fd21c8 | 50 | |
| 8e5e9b94 | 51 | __led_set is called to change the state of the LED. |
| 65fd21c8 TR |
52 | |
| 53 | __led_toggle is called to toggle the current state of the LED. | |
| 54 | ||
| 55 | Colour LED | |
| 56 | ======================================== | |
| 57 | ||
| 8e5e9b94 | 58 | Colour LED's are at present only used by ARM. |
| 65fd21c8 TR |
59 | |
| 60 | The functions names explain their purpose. | |
| 61 | ||
| 62 | coloured_LED_init | |
| 63 | red_LED_on | |
| 64 | red_LED_off | |
| 65 | green_LED_on | |
| 66 | green_LED_off | |
| 67 | yellow_LED_on | |
| 68 | yellow_LED_off | |
| 69 | blue_LED_on | |
| 70 | blue_LED_off | |
| 71 | ||
| ea0364f1 | 72 | These are weakly defined in arch/arm/lib/board.c to noops. Where applicable, define |
| 65fd21c8 TR |
73 | these functions in the board specific source. |
| 74 | ||
| 75 | TBD : Describe older board dependent macros similar to what is done for | |
| 65fd21c8 TR |
76 | |
| 77 | TBD : Describe general support via asm/status_led.h |