drm/mediatek: dpi: Add input_2pixel config support

The input pixel per iteration could be different, so we add a new config
"input_2pixel" to control this.
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220705102530.1344-4-rex-bc.chen@mediatek.com/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -124,6 +124,8 @@ struct mtk_dpi_yc_limit {
  * @is_ck_de_pol: Support CK/DE polarity.
  * @swap_input_support: Support input swap function.
  * @support_direct_pin: IP supports direct connection to dpi panels.
+ * @input_2pixel: Input pixel of dp_intf is 2 pixel per round, so enable this
+ *		  config to enable this feature.
  * @dimension_mask: Mask used for HWIDTH, HPORCH, VSYNC_WIDTH and VSYNC_PORCH
  *		    (no shift).
  * @hvsize_mask: Mask of HSIZE and VSIZE mask (no shift).
@@ -141,6 +143,7 @@ struct mtk_dpi_conf {
 	bool is_ck_de_pol;
 	bool swap_input_support;
 	bool support_direct_pin;
+	bool input_2pixel;
 	u32 dimension_mask;
 	u32 hvsize_mask;
 	u32 channel_swap_shift;
@@ -588,6 +591,10 @@ static int mtk_dpi_set_display_mode(struct mtk_dpi *dpi,
 		mtk_dpi_dual_edge(dpi);
 		mtk_dpi_config_disable_edge(dpi);
 	}
+	if (dpi->conf->input_2pixel) {
+		mtk_dpi_mask(dpi, DPI_CON, DPINTF_INPUT_2P_EN,
+			     DPINTF_INPUT_2P_EN);
+	}
 	mtk_dpi_sw_reset(dpi, false);
 
 	return 0;

drivers/gpu/drm/mediatek/mtk_dpi_regs.h

@@ -40,6 +40,7 @@
 #define FAKE_DE_LEVEN			BIT(21)
 #define FAKE_DE_RODD			BIT(22)
 #define FAKE_DE_REVEN			BIT(23)
+#define DPINTF_INPUT_2P_EN		BIT(29)
 
 #define DPI_OUTPUT_SETTING	0x14
 #define CH_SWAP				0