projects / GitHub / mt8127 / android_kernel_alcatel_ttab.git / blame
| Commit | Line | Data |
|---|---|---|
| 32abb478 SJ |
1 | Kernel driver for lm3556 |
| 2 | ======================== | |
| 3 | ||
| 4 | *Texas Instrument: | |
| 5 | 1.5 A Synchronous Boost LED Flash Driver w/ High-Side Current Source | |
| 6 | * Datasheet: http://www.national.com/ds/LM/LM3556.pdf | |
| 7 | ||
| 8 | Authors: | |
| 9 | Daniel Jeong | |
| 10 | Contact:Daniel Jeong(daniel.jeong-at-ti.com, gshark.jeong-at-gmail.com) | |
| 11 | ||
| 12 | Description | |
| 13 | ----------- | |
| 14 | There are 3 functions in LM3556, Flash, Torch and Indicator. | |
| 15 | ||
| 16 | FLASH MODE | |
| 17 | In Flash Mode, the LED current source(LED) provides 16 target current levels | |
| 18 | from 93.75 mA to 1500 mA.The Flash currents are adjusted via the CURRENT | |
| 19 | CONTROL REGISTER(0x09).Flash mode is activated by the ENABLE REGISTER(0x0A), | |
| 20 | or by pulling the STROBE pin HIGH. | |
| 21 | LM3556 Flash can be controlled through sys/class/leds/flash/brightness file | |
| 22 | * if STROBE pin is enabled, below example control brightness only, and | |
| 23 | ON / OFF will be controlled by STROBE pin. | |
| 24 | ||
| 25 | Flash Example: | |
| 26 | OFF : #echo 0 > sys/class/leds/flash/brightness | |
| 27 | 93.75 mA: #echo 1 > sys/class/leds/flash/brightness | |
| 28 | ... ..... | |
| 29 | 1500 mA: #echo 16 > sys/class/leds/flash/brightness | |
| 30 | ||
| 31 | TORCH MODE | |
| 32 | In Torch Mode, the current source(LED) is programmed via the CURRENT CONTROL | |
| 33 | REGISTER(0x09).Torch Mode is activated by the ENABLE REGISTER(0x0A) or by the | |
| 34 | hardware TORCH input. | |
| 35 | LM3556 torch can be controlled through sys/class/leds/torch/brightness file. | |
| 36 | * if TORCH pin is enabled, below example control brightness only, | |
| 37 | and ON / OFF will be controlled by TORCH pin. | |
| 38 | ||
| 39 | Torch Example: | |
| 40 | OFF : #echo 0 > sys/class/leds/torch/brightness | |
| 41 | 46.88 mA: #echo 1 > sys/class/leds/torch/brightness | |
| 42 | ... ..... | |
| 43 | 375 mA : #echo 8 > sys/class/leds/torch/brightness | |
| 44 | ||
| 45 | INDICATOR MODE | |
| 46 | Indicator pattern can be set through sys/class/leds/indicator/pattern file, | |
| 47 | and 4 patterns are pre-defined in indicator_pattern array. | |
| 48 | According to N-lank, Pulse time and N Period values, different pattern wiill | |
| 49 | be generated.If you want new patterns for your own device, change | |
| 50 | indicator_pattern array with your own values and INDIC_PATTERN_SIZE. | |
| 51 | Please refer datasheet for more detail about N-Blank, Pulse time and N Period. | |
| 52 | ||
| 53 | Indicator pattern example: | |
| 54 | pattern 0: #echo 0 > sys/class/leds/indicator/pattern | |
| 55 | .... | |
| 56 | pattern 3: #echo 3 > sys/class/leds/indicator/pattern | |
| 57 | ||
| 58 | Indicator brightness can be controlled through | |
| 59 | sys/class/leds/indicator/brightness file. | |
| 60 | ||
| 61 | Example: | |
| 62 | OFF : #echo 0 > sys/class/leds/indicator/brightness | |
| 63 | 5.86 mA : #echo 1 > sys/class/leds/indicator/brightness | |
| 64 | ........ | |
| 65 | 46.875mA : #echo 8 > sys/class/leds/indicator/brightness | |
| 66 | ||
| 67 | Notes | |
| 68 | ----- | |
| 69 | Driver expects it is registered using the i2c_board_info mechanism. | |
| 70 | To register the chip at address 0x63 on specific adapter, set the platform data | |
| 71 | according to include/linux/platform_data/leds-lm3556.h, set the i2c board info | |
| 72 | ||
| 73 | Example: | |
| 74 | static struct i2c_board_info __initdata board_i2c_ch4[] = { | |
| 75 | { | |
| 76 | I2C_BOARD_INFO(LM3556_NAME, 0x63), | |
| 77 | .platform_data = &lm3556_pdata, | |
| 78 | }, | |
| 79 | }; | |
| 80 | ||
| 81 | and register it in the platform init function | |
| 82 | ||
| 83 | Example: | |
| 84 | board_register_i2c_bus(4, 400, | |
| 85 | board_i2c_ch4, ARRAY_SIZE(board_i2c_ch4)); |