Add generic PWM host commands for setting + getting duty cycle. PWMs can
be controlled through index (board-specific meaning) or by type
(currently KB backlight and display backlight are supported, more can be
added as needed).
BUG=chrome-os-partner:52002
BRANCH=None
TEST=Manual on chell.
`ectool pwmsetduty kb 100` - Verify KB backlight goes to 100%
`ectool pwmgetduty kb` - Prints 100
`ectool pwmgetduty 0` - Prints 100
`ectool pwmsetduty 0 0` - Verify KB backlight goes to 0%
`ectool pwmgetduty kb` - Prints 0
`ectool pwmgetduty disp` - Error res 3 (unsupported PWM type)
`ectool pwmsetduty 1` - Error res 3 (non-existent PWM index)
Signed-off-by: Shawn Nematbakhsh <shawnn@chromium.org>
Change-Id: I607c92a291e6c2e3af8238eaf22ad2bb81ffc805
Reviewed-on: https://chromium-review.googlesource.com/344012
Commit-Ready: Shawn N <shawnn@chromium.org>
Tested-by: Shawn N <shawnn@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Reviewed-by: Mary Ruthven <mruthven@chromium.org>
9494fc0dd1