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> --- Changes in v3: - Dissolved function s6e88a0_ams427ap24_parse_dt() and placed the parsing in the probe function. Changed the parsing from of_property_read_bool() to device_property_read_bool(). --- drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c index 9e211be432d7..cbd51351a325 100644 --- a/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c +++ b/drivers/gpu/drm/panel/panel-samsung-s6e88a0-ams427ap24.c @@ -32,6 +32,7 @@ struct s6e88a0_ams427ap24 { struct mipi_dsi_device *dsi; struct regulator_bulk_data *supplies; struct gpio_desc *reset_gpio; + bool flip_horizontal; }; static const struct regulator_bulk_data s6e88a0_ams427ap24_supplies[] = { @@ -538,6 +539,10 @@ static int s6e88a0_ams427ap24_on(struct s6e88a0_ams427ap24 *ctx) mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xcc, 0x4c); mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf2, 0x03, 0x0d); mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf1, 0xa5, 0xa5); + + if (ctx->flip_horizontal) + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xcb, 0x0e); + mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xf0, 0xa5, 0xa5); mipi_dsi_dcs_write_seq_multi(&dsi_ctx, 0xfc, 0xa5, 0xa5); @@ -698,6 +703,8 @@ static int s6e88a0_ams427ap24_probe(struct mipi_dsi_device *dsi) DRM_MODE_CONNECTOR_DSI); ctx->panel.prepare_prev_first = true; + ctx->flip_horizontal = device_property_read_bool(dev, "flip-horizontal"); + ret = s6e88a0_ams427ap24_register_backlight(ctx); if (ret < 0) return ret; -- 2.39.5
