From fc44f3636a4db6544fd1532280e8adcd1ef13ba2 Mon Sep 17 00:00:00 2001 From: Francesco Dolcini Date: Thu, 22 Sep 2022 14:43:06 +0200 Subject: drm/bridge: lt8912b: clarify lvds output status Add comments on the lt8912_write_lvds_config() config to document the current settings and to make it clear that this is a hardcoded configuration not relevant for the HDMI output (could be removed without affecting the HDMI port). No changes on the actual register writes. Signed-off-by: Francesco Dolcini Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Neil Armstrong Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-5-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 26 +++++++++++++++++--------- 1 file changed, 17 insertions(+), 9 deletions(-) (limited to 'drivers/gpu/drm/bridge/lontium-lt8912b.c') diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index 28bad30dc4e5..580a997092a1 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -165,24 +165,32 @@ static int lt8912_write_rxlogicres_config(struct lt8912 *lt) return ret; }; +/* enable LVDS output with some hardcoded configuration, not required for the HDMI output */ static int lt8912_write_lvds_config(struct lt8912 *lt) { const struct reg_sequence seq[] = { + // lvds power up {0x44, 0x30}, {0x51, 0x05}, - {0x50, 0x24}, - {0x51, 0x2d}, - {0x52, 0x04}, - {0x69, 0x0e}, + + // core pll bypass + {0x50, 0x24}, // cp=50uA + {0x51, 0x2d}, // Pix_clk as reference, second order passive LPF PLL + {0x52, 0x04}, // loopdiv=0, use second-order PLL + {0x69, 0x0e}, // CP_PRESET_DIV_RATIO {0x69, 0x8e}, {0x6a, 0x00}, - {0x6c, 0xb8}, + {0x6c, 0xb8}, // RGD_CP_SOFT_K_EN,RGD_CP_SOFT_K[13:8] {0x6b, 0x51}, - {0x04, 0xfb}, + + {0x04, 0xfb}, // core pll reset {0x04, 0xff}, - {0x7f, 0x00}, - {0xa8, 0x13}, - {0x02, 0xf7}, + + // scaler bypass + {0x7f, 0x00}, // disable scaler + {0xa8, 0x13}, // 0x13: JEIDA, 0x33: VESA + + {0x02, 0xf7}, // lvds pll reset {0x02, 0xff}, {0x03, 0xcf}, {0x03, 0xff}, -- cgit From e3e7f178d4d82743786d5a002b714b5d516f5870 Mon Sep 17 00:00:00 2001 From: Philippe Schenker Date: Thu, 22 Sep 2022 14:43:03 +0200 Subject: drm/bridge: lt8912b: add vsync hsync Currently the bridge driver does not take care whether or not the display needs positive/negative vertical/horizontal syncs. Pass these two flags to the bridge from the EDID that was read out from the display. Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-2-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/bridge/lontium-lt8912b.c') diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index 580a997092a1..f70da3785c4b 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -276,7 +276,7 @@ static int lt8912_video_setup(struct lt8912 *lt) u32 hactive, h_total, hpw, hfp, hbp; u32 vactive, v_total, vpw, vfp, vbp; u8 settle = 0x08; - int ret; + int ret, hsync_activehigh, vsync_activehigh; if (!lt) return -EINVAL; @@ -286,12 +286,14 @@ static int lt8912_video_setup(struct lt8912 *lt) hpw = lt->mode.hsync_len; hbp = lt->mode.hback_porch; h_total = hactive + hfp + hpw + hbp; + hsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_HSYNC_HIGH; vactive = lt->mode.vactive; vfp = lt->mode.vfront_porch; vpw = lt->mode.vsync_len; vbp = lt->mode.vback_porch; v_total = vactive + vfp + vpw + vbp; + vsync_activehigh = lt->mode.flags & DISPLAY_FLAGS_VSYNC_HIGH; if (vactive <= 600) settle = 0x04; @@ -325,6 +327,11 @@ static int lt8912_video_setup(struct lt8912 *lt) ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3e, hfp & 0xff); ret |= regmap_write(lt->regmap[I2C_CEC_DSI], 0x3f, hfp >> 8); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(0), + vsync_activehigh ? BIT(0) : 0); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1), + hsync_activehigh ? BIT(1) : 0); + return ret; } -- cgit From d25404a359b24a887db56b52064b754f79921bb7 Mon Sep 17 00:00:00 2001 From: Philippe Schenker Date: Thu, 22 Sep 2022 14:43:04 +0200 Subject: drm/bridge: lt8912b: set hdmi or dvi mode The Lontium LT8912 does have a setting for DVI or HDMI. This patch reads from EDID what the display needs and sets it accordingly. Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-3-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'drivers/gpu/drm/bridge/lontium-lt8912b.c') diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index f70da3785c4b..caf96c3a373f 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -331,6 +331,8 @@ static int lt8912_video_setup(struct lt8912 *lt) vsync_activehigh ? BIT(0) : 0); ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xab, BIT(1), hsync_activehigh ? BIT(1) : 0); + ret |= regmap_update_bits(lt->regmap[I2C_MAIN], 0xb2, BIT(0), + lt->connector.display_info.is_hdmi ? BIT(0) : 0); return ret; } -- cgit From 2ab69739209c843a47af82c0620036b233c83688 Mon Sep 17 00:00:00 2001 From: Francesco Dolcini Date: Thu, 22 Sep 2022 14:43:05 +0200 Subject: drm/bridge: lt8912b: fix corrupted image output Correct I2C address for the register list in lt8912_write_lvds_config(), these registers are on the first I2C address (0x48), the current function is just writing garbage to the wrong registers and this creates multiple issues (artifacts and output completely corrupted) on some HDMI displays. Correct I2C address comes from Lontium documentation and it is the one used on other out-of-tree LT8912B drivers [1]. [1] https://github.com/boundarydevices/linux/blob/boundary-imx_5.10.x_2.0.0/drivers/video/lt8912.c#L296 Fixes: 30e2ae943c26 ("drm/bridge: Introduce LT8912B DSI to HDMI bridge") Signed-off-by: Francesco Dolcini Signed-off-by: Philippe Schenker Acked-by: Adrien Grassein Signed-off-by: Robert Foss Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-4-dev@pschenker.ch Link: https://patchwork.freedesktop.org/patch/msgid/20220922124306.34729-5-dev@pschenker.ch --- drivers/gpu/drm/bridge/lontium-lt8912b.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/gpu/drm/bridge/lontium-lt8912b.c') diff --git a/drivers/gpu/drm/bridge/lontium-lt8912b.c b/drivers/gpu/drm/bridge/lontium-lt8912b.c index caf96c3a373f..3e870d45f881 100644 --- a/drivers/gpu/drm/bridge/lontium-lt8912b.c +++ b/drivers/gpu/drm/bridge/lontium-lt8912b.c @@ -196,7 +196,7 @@ static int lt8912_write_lvds_config(struct lt8912 *lt) {0x03, 0xff}, }; - return regmap_multi_reg_write(lt->regmap[I2C_CEC_DSI], seq, ARRAY_SIZE(seq)); + return regmap_multi_reg_write(lt->regmap[I2C_MAIN], seq, ARRAY_SIZE(seq)); }; static inline struct lt8912 *bridge_to_lt8912(struct drm_bridge *b) -- cgit