From 7d8d0b4dcc535357d44ddeff154508f147c14e2a Mon Sep 17 00:00:00 2001 From: Rex-BC Chen Date: Wed, 9 Mar 2022 15:36:36 +0800 Subject: [PATCH] drm/mediatek: implement the DSI HS packets aligned Some DSI RX devices (for example, anx7625) require last alignment of packets on all lanes after each row of data is sent. Otherwise, there will be some issues of shift or scroll for screen. Take horizontal_sync_active_byte for a example, we roundup the HSA packet data to lane number, and the subtraction of 2 is the packet data value added by the roundup operation, making the long packets are integer multiples of lane number. This value (2) varies with the lane number, and that is the reason we do this operation when the lane number is 4. In the previous operation of function "mtk_dsi_config_vdo_timing", the length of HSA and HFP data packets has been adjusted to an integration multiple of lane number. Since the number of RGB data packets cannot be guaranteed to be an integer multiple of lane number, we modify the data packet length of HBP so that the number of HBP + RGB is equal to the lane number. So after sending a line of data (HSA + HBP + RGB + HFP), the data lanes are aligned. Signed-off-by: Jitao Shi Signed-off-by: Rex-BC Chen Signed-off-by: Xinlei Lee Reviewed-by: Andrzej Hajda Reviewed-by: AngeloGioacchino Del Regno Acked-by: Chun-Kuang Hu Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220309073637.3591-3-rex-bc.chen@mediatek.com --- drivers/gpu/drm/mediatek/mtk_dsi.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/drivers/gpu/drm/mediatek/mtk_dsi.c b/drivers/gpu/drm/mediatek/mtk_dsi.c index 5d90d2eb..e91b3ff 100644 --- a/drivers/gpu/drm/mediatek/mtk_dsi.c +++ b/drivers/gpu/drm/mediatek/mtk_dsi.c @@ -500,6 +500,18 @@ 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->mode_flags & MIPI_DSI_HS_PKT_END_ALIGNED) && + (dsi->lanes == 4)) { + 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); -- 2.7.4