Commit e14cba94 authored by AngeloGioacchino Del Regno's avatar AngeloGioacchino Del Regno Committed by Chun-Kuang Hu
Browse files

drm/mediatek: dsi: Use mipi_dsi_pixel_format_to_bpp() helper function 



Instead of open coding, use the mipi_dsi_pixel_format_to_bpp() helper
function from drm_mipi_dsi.h in mtk_dsi_poweron() and for validation
in mtk_dsi_bridge_mode_valid().

Note that this function changes the behavior of this driver: previously,
in case of unknown formats, it would (wrongly) assume that it should
account for a 24-bits format - now it will return an error and refuse
to set clocks and/or enable the DSI.

This is done because setting the wrong data rate will only produce a
garbage output that the display will misinterpret both because this
driver doesn't actually provide any extra-spec format support and/or
because the data rate (hence, the HS clock) will be wrong.

Reviewed-by: default avatarAlexandre Mergnat <amergnat@baylibre.com>
Signed-off-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: default avatarCK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/dri-devel/patch/20240215085316.56835-10-angelogioacchino.delregno@collabora.com/


Signed-off-by: default avatarChun-Kuang Hu <chunkuang.hu@kernel.org>
parent 2aa9514a

drivers/gpu/drm/mediatek/mtk_dsi.c

+9 −17
Original line number Diff line number Diff line
@@ -598,19 +598,12 @@ static int mtk_dsi_poweron(struct mtk_dsi *dsi) 
	if (++dsi->refcount != 1)

		return 0;



	switch (dsi->format) {

	case MIPI_DSI_FMT_RGB565:

		bit_per_pixel = 16;

		break;

	case MIPI_DSI_FMT_RGB666_PACKED:

		bit_per_pixel = 18;

		break;

	case MIPI_DSI_FMT_RGB666:

	case MIPI_DSI_FMT_RGB888:

	default:

		bit_per_pixel = 24;

		break;

	ret = mipi_dsi_pixel_format_to_bpp(dsi->format);

	if (ret < 0) {

		dev_err(dev, "Unknown MIPI DSI format %d\n", dsi->format);

		return ret;

	}

	bit_per_pixel = ret;



	dsi->data_rate = DIV_ROUND_UP_ULL(dsi->vm.pixelclock * bit_per_pixel,

					  dsi->lanes);
@@ -793,12 +786,11 @@ mtk_dsi_bridge_mode_valid(struct drm_bridge *bridge, 
			  const struct drm_display_mode *mode)

{

	struct mtk_dsi *dsi = bridge_to_dsi(bridge);

	u32 bpp;

	int bpp;



	if (dsi->format == MIPI_DSI_FMT_RGB565)

		bpp = 16;

	else

		bpp = 24;

	bpp = mipi_dsi_pixel_format_to_bpp(dsi->format);

	if (bpp < 0)

		return MODE_ERROR;



	if (mode->clock * bpp / dsi->lanes > 1500000)

		return MODE_CLOCK_HIGH;