diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/leds/leds-lm3556.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/leds/leds-lm3556.txt')
-rw-r--r-- | kernel/Documentation/leds/leds-lm3556.txt | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/kernel/Documentation/leds/leds-lm3556.txt b/kernel/Documentation/leds/leds-lm3556.txt new file mode 100644 index 000000000..62278e871 --- /dev/null +++ b/kernel/Documentation/leds/leds-lm3556.txt @@ -0,0 +1,85 @@ +Kernel driver for lm3556 +======================== + +*Texas Instrument: + 1.5 A Synchronous Boost LED Flash Driver w/ High-Side Current Source +* Datasheet: http://www.national.com/ds/LM/LM3556.pdf + +Authors: + Daniel Jeong + Contact:Daniel Jeong(daniel.jeong-at-ti.com, gshark.jeong-at-gmail.com) + +Description +----------- +There are 3 functions in LM3556, Flash, Torch and Indicator. + +FLASH MODE +In Flash Mode, the LED current source(LED) provides 16 target current levels +from 93.75 mA to 1500 mA.The Flash currents are adjusted via the CURRENT +CONTROL REGISTER(0x09).Flash mode is activated by the ENABLE REGISTER(0x0A), +or by pulling the STROBE pin HIGH. +LM3556 Flash can be controlled through sys/class/leds/flash/brightness file +* if STROBE pin is enabled, below example control brightness only, and +ON / OFF will be controlled by STROBE pin. + +Flash Example: +OFF : #echo 0 > sys/class/leds/flash/brightness +93.75 mA: #echo 1 > sys/class/leds/flash/brightness +... ..... +1500 mA: #echo 16 > sys/class/leds/flash/brightness + +TORCH MODE +In Torch Mode, the current source(LED) is programmed via the CURRENT CONTROL +REGISTER(0x09).Torch Mode is activated by the ENABLE REGISTER(0x0A) or by the +hardware TORCH input. +LM3556 torch can be controlled through sys/class/leds/torch/brightness file. +* if TORCH pin is enabled, below example control brightness only, +and ON / OFF will be controlled by TORCH pin. + +Torch Example: +OFF : #echo 0 > sys/class/leds/torch/brightness +46.88 mA: #echo 1 > sys/class/leds/torch/brightness +... ..... +375 mA : #echo 8 > sys/class/leds/torch/brightness + +INDICATOR MODE +Indicator pattern can be set through sys/class/leds/indicator/pattern file, +and 4 patterns are pre-defined in indicator_pattern array. +According to N-lank, Pulse time and N Period values, different pattern wiill +be generated.If you want new patterns for your own device, change +indicator_pattern array with your own values and INDIC_PATTERN_SIZE. +Please refer datasheet for more detail about N-Blank, Pulse time and N Period. + +Indicator pattern example: +pattern 0: #echo 0 > sys/class/leds/indicator/pattern +.... +pattern 3: #echo 3 > sys/class/leds/indicator/pattern + +Indicator brightness can be controlled through +sys/class/leds/indicator/brightness file. + +Example: +OFF : #echo 0 > sys/class/leds/indicator/brightness +5.86 mA : #echo 1 > sys/class/leds/indicator/brightness +........ +46.875mA : #echo 8 > sys/class/leds/indicator/brightness + +Notes +----- +Driver expects it is registered using the i2c_board_info mechanism. +To register the chip at address 0x63 on specific adapter, set the platform data +according to include/linux/platform_data/leds-lm3556.h, set the i2c board info + +Example: + static struct i2c_board_info board_i2c_ch4[] __initdata = { + { + I2C_BOARD_INFO(LM3556_NAME, 0x63), + .platform_data = &lm3556_pdata, + }, + }; + +and register it in the platform init function + +Example: + board_register_i2c_bus(4, 400, + board_i2c_ch4, ARRAY_SIZE(board_i2c_ch4)); |