b694131102
At least Bay Trail (BYT) and Cherry Trail (CHT) devices can use 1 of 2 different PWM controllers for controlling the LCD's backlight brightness. Either the one integrated into the PMIC or the one integrated into the SoC (the 1st LPSS PWM controller). So far in the LPSS code on BYT we have skipped registering the LPSS PWM controller "pwm_backlight" lookup entry when a Crystal Cove PMIC is present, assuming that in this case the PMIC PWM controller will be used. On CHT we have been relying on only 1 of the 2 PWM controllers being enabled in the DSDT at the same time; and always registered the lookup. So far this has been working, but the correct way to determine which PWM controller needs to be used is by checking a bit in the VBT table and recently I've learned about 2 different BYT devices: Point of View MOBII TAB-P800W Acer Switch 10 SW5-012 Which use a Crystal Cove PMIC, yet the LCD is connected to the SoC/LPSS PWM controller (and the VBT correctly indicates this), so here our old heuristics fail. This commit fixes using the wrong PWM controller on these devices by calling pwm_get() for the right PWM controller based on the VBT dsi.config.pwm_blc bit. Note this is part of a series which contains 2 other patches which renames the PWM lookup for the 1st SoC/LPSS PWM from "pwm_backlight" to "pwm_pmic_backlight" and the PWM lookup for the Crystal Cove PMIC PWM from "pwm_backlight" to "pwm_pmic_backlight". Acked-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20191216202906.1662893-4-hdegoede@redhat.com
Linux kernel
============
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