Hi,
On 30-01-17 23:21, Andy Shevchenko wrote:
On Sun, Jan 22, 2017 at 5:24 PM, Hans de Goede <hdegoede@xxxxxxxxxx> wrote:
On x86 we do not have devicetree to link the pwm controller and
the display controller together. So someone needs to call
pwm_add_table() to create the link, so that the i915 driver's
pwm_get(dev, "pwm_backlight") call returns the lpss' pwm0.
The pwm subsystem does not want to have pwm_add_table() calls
directly in pwm drivers (this leads to probe ordering issues),
so lets do it here since the acpi-lpss code is always builtin.
Hans, just to be sure, the device you have is using LPSS pwm for backlight.
Correct, I've 2 cherrytrail tablets and one mini laptop, the 2 tablets
both use LPSS for backlight, the mini laptop just arrived and I
still need to put Linux on it.
Since I just recall that on some (Baytrail) models we have PMIC
(Crystal Cove) that responsible for PWM for backlight.
And we have no PMIC driver in kernel for CherryTrail (Dollar Cove).
Right, on baytrail the pwm_crc driver is used which AFAIK is
for CRystal Cove.
Regards,
Hans
