[PATCH v7 2/3] drm/mediatek: implment the dsi hs packets aligned

[Jitao Shi]

Some dsi devices require the packets on lanes aligned at the end,
or the screen will shift or scroll.

Signed-off-by: Jitao Shi <jitao.shi at mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_dsi.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c
index 93b40c245f00..9d72e6dce0bf 100644
--- a/drivers/gpu/drm/mediatek/mtk_dsi.c
+++ b/drivers/gpu/drm/mediatek/mtk_dsi.c
@@ -194,6 +194,8 @@ struct mtk_dsi {
 	struct clk *hs_clk;
 
 	u32 data_rate;
+	/* force dsi line end without dsi_null data */
+	bool hs_packet_end_aligned;
 
 	unsigned long mode_flags;
 	enum mipi_dsi_pixel_format format;
@@ -499,6 +501,13 @@ static void mtk_dsi_config_vdo_timing(struct mtk_dsi *dsi)
 		DRM_WARN("HFP + HBP less than d-phy, FPS will under 60Hz\n");
 	}
 
+	if (dsi->hs_packet_end_aligned) {
+		horizontal_sync_active_byte = roundup(horizontal_sync_active_byte, dsi->lanes) - 2;
+		horizontal_frontporch_byte = roundup(horizontal_frontporch_byte, dsi->lanes) - 2;
+		horizontal_backporch_byte = roundup(horizontal_backporch_byte, dsi->lanes) - 2;
+		horizontal_backporch_byte -= (vm->hactive * dsi_tmp_buf_bpp + 2) % dsi->lanes;
+	}
+
 	writel(horizontal_sync_active_byte, dsi->regs + DSI_HSA_WC);
 	writel(horizontal_backporch_byte, dsi->regs + DSI_HBP_WC);
 	writel(horizontal_frontporch_byte, dsi->regs + DSI_HFP_WC);
@@ -793,6 +802,7 @@ static int mtk_dsi_host_attach(struct mipi_dsi_host *host,
 	dsi->lanes = device->lanes;
 	dsi->format = device->format;
 	dsi->mode_flags = device->mode_flags;
+	dsi->hs_packet_end_aligned = device->hs_packet_end_aligned;
 
 	return 0;
 }
-- 
2.25.1