61 lines
2.1 KiB
ReStructuredText
61 lines
2.1 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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======================================
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Samsung S2M Series PMIC RGB LED Driver
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======================================
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Description
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-----------
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The RGB LED on the S2M series PMIC hardware features a three-channel LED that
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is grouped together as a single device. Furthermore, it supports 8-bit
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brightness control for each channel. This LED is typically used as a status
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indicator in mobile devices. It also supports various parameters for hardware
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patterns.
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The hardware pattern can be programmed using the "pattern" trigger, using the
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hw_pattern attribute.
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/sys/class/leds/<led>/repeat
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----------------------------
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The hardware supports only indefinitely repeating patterns. The repeat
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attribute must be set to -1 for hardware patterns to function.
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/sys/class/leds/<led>/hw_pattern
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--------------------------------
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Specify a hardware pattern for the RGB LEDs.
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The pattern is a series of brightness levels and durations in milliseconds.
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There should be only one non-zero brightness level. Unlike the results
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described in leds-trigger-pattern, the transitions between on and off states
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are smoothed out by the hardware.
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Simple pattern::
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"255 3000 0 1000"
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255 -+ ''''''-. .-'''''''-.
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| '. .' '.
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| \ / \
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| '. .' '.
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| '-.......-' '-
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0 -+-------+-------+-------+-------+-------+-------+--> time (s)
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0 1 2 3 4 5 6
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As described in leds-trigger-pattern, it is also possible to use zero-length
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entries to disable the ramping mechanism.
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On-Off pattern::
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"255 1000 255 0 0 1000 0 0"
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255 -+ ------+ +-------+ +-------+
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| +-------+ +-------+ +-------
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0 -+-------+-------+-------+-------+-------+-------+--> time (s)
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0 1 2 3 4 5 6
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