From fcc22c5f9ddaa8d1bb051878cc7e5f928b9973d8 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 31 Jul 2018 11:12:27 +0100 Subject: drm/i2c: tda998x: improve correctness of quantisation range CEA-861 says: "A Source shall not send a non-zero Q value that does not correspond to the default RGB Quantization Range for the transmitted Picture unless the Sink indicates support for the Q bit in a Video Capabilities Data Block." Make TDA998x compliant by using the helper to set the quantisation range in the infoframe, and using the TDA998x's colour scaling to appropriately adjust the RGB values sent to the monitor. This ensures that monitors that do not support the Q bit are sent RGB values that are within the expected range. Monitors with support for the Q bit will be sent full-range RGB. Reviewed-by: Brian Starkey Tested-by: Sven Van Asbroeck Signed-off-by: Russell King --- drivers/gpu/drm/i2c/tda998x_drv.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) (limited to 'drivers/gpu/drm') diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index d4409aa5ed7a..2d69aef556a5 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -67,6 +67,7 @@ struct tda998x_priv { bool is_on; bool supports_infoframes; bool sink_has_audio; + enum hdmi_quantization_range rgb_quant_range; u8 vip_cntrl_0; u8 vip_cntrl_1; u8 vip_cntrl_2; @@ -870,6 +871,8 @@ tda998x_write_avi(struct tda998x_priv *priv, const struct drm_display_mode *mode drm_hdmi_avi_infoframe_from_display_mode(&frame.avi, &priv->connector, mode); frame.avi.quantization_range = HDMI_QUANTIZATION_RANGE_FULL; + drm_hdmi_avi_infoframe_quant_range(&frame.avi, &priv->connector, mode, + priv->rgb_quant_range); tda998x_write_if(priv, DIP_IF_FLAGS_IF2, REG_IF2_HB0, &frame); } @@ -1426,6 +1429,16 @@ static void tda998x_bridge_mode_set(struct drm_bridge *bridge, u16 de_pix_s, de_pix_e; u8 reg, div, rep, sel_clk; + /* + * Since we are "computer" like, our source invariably produces + * full-range RGB. If the monitor supports full-range, then use + * it, otherwise reduce to limited-range. + */ + priv->rgb_quant_range = + priv->connector.display_info.rgb_quant_range_selectable ? + HDMI_QUANTIZATION_RANGE_FULL : + drm_default_rgb_quant_range(adjusted_mode); + /* * Internally TDA998x is using ITU-R BT.656 style sync but * we get VESA style sync. TDA998x is using a reference pixel @@ -1541,10 +1554,25 @@ static void tda998x_bridge_mode_set(struct drm_bridge *bridge, reg_write(priv, REG_PLL_SERIAL_2, PLL_SERIAL_2_SRL_NOSC(div) | PLL_SERIAL_2_SRL_PR(rep)); - /* set color matrix bypass flag: */ - reg_write(priv, REG_MAT_CONTRL, MAT_CONTRL_MAT_BP | - MAT_CONTRL_MAT_SC(1)); - reg_set(priv, REG_FEAT_POWERDOWN, FEAT_POWERDOWN_CSC); + /* set color matrix according to output rgb quant range */ + if (priv->rgb_quant_range == HDMI_QUANTIZATION_RANGE_LIMITED) { + static u8 tda998x_full_to_limited_range[] = { + MAT_CONTRL_MAT_SC(2), + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x03, 0x6f, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x03, 0x6f, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x03, 0x6f, + 0x00, 0x40, 0x00, 0x40, 0x00, 0x40 + }; + reg_clear(priv, REG_FEAT_POWERDOWN, FEAT_POWERDOWN_CSC); + reg_write_range(priv, REG_MAT_CONTRL, + tda998x_full_to_limited_range, + sizeof(tda998x_full_to_limited_range)); + } else { + reg_write(priv, REG_MAT_CONTRL, MAT_CONTRL_MAT_BP | + MAT_CONTRL_MAT_SC(1)); + reg_set(priv, REG_FEAT_POWERDOWN, FEAT_POWERDOWN_CSC); + } /* set BIAS tmds value: */ reg_write(priv, REG_ANA_GENERAL, 0x09); -- cgit v1.2.3