On Mon, Oct 28, 2024 at 12:42 AM Jakob Hauser <jahau@xxxxxxxxxxxxxx> wrote: > The way of implementing a flip option follows the existing > panel-samsung-s6e8aa0.c [1][2][3]. > > The value to flip the screen is taken from a downstream kernel file of > a similar but older panel [4]. The mipi clock [5] for the new panel > samsung-s6e88a0-ams427ap24 matches 461 MHz and a hardware read-out of the > 0xcb values corresponds to revision R01 of that older panel [6]. Although > for samsung-s6e88a0-ams427ap24 that's in non-flipped state while in this > older driver it seems to be the other way around. Further up there is a > hint [7] basically saying for revision R01 to change the first word of the > 0xcb command from 0x06 to 0x0e, which is actually setting BIT(3) of that > word. This causes a horizontal flip. > > [1] https://github.com/torvalds/linux/blob/v6.11/drivers/gpu/drm/panel/panel-samsung-s6e8aa0.c#L103 > [2] https://github.com/torvalds/linux/blob/v6.11/drivers/gpu/drm/panel/panel-samsung-s6e8aa0.c#L207-L211 > [3] https://github.com/torvalds/linux/blob/v6.11/drivers/gpu/drm/panel/panel-samsung-s6e8aa0.c#L954-L974 > [4] https://github.com/LineageOS/android_kernel_samsung_msm8930-common/blob/lineage-15.1/drivers/video/msm/mipi_samsung_oled_video_qhd_pt-8930.c > [5] https://github.com/LineageOS/android_kernel_samsung_msm8930-common/blob/lineage-15.1/drivers/video/msm/mipi_samsung_oled_video_qhd_pt-8930.c#L2027-L2028 > [6] https://github.com/LineageOS/android_kernel_samsung_msm8930-common/blob/lineage-15.1/drivers/video/msm/mipi_samsung_oled_video_qhd_pt-8930.c#L137-L151 > [7] https://github.com/LineageOS/android_kernel_samsung_msm8930-common/blob/lineage-15.1/drivers/video/msm/mipi_samsung_oled_video_qhd_pt-8930.c#L66-L74 > > Signed-off-by: Jakob Hauser <jahau@xxxxxxxxxxxxxx> > Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx> Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> Yours, Linus Walleij
