drm/vc4: hdmi: Define colorspace matrices

The current CSC setup code for the BCM2711 uses a sequence of register
writes to configure the CSC depending on whether we output using a full
or limited range.

However, with the upcoming introduction of the YUV output, we're going
to add new matrices to perform the conversions, so we should switch to
something a bit more flexible that takes the matrix as an argument and
programs the CSC accordingly.

Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-10-maxime@cerno.tech

diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
index 682c3c9..3a3c820 100644 (file)
--- a/drivers/gpu/drm/vc4/vc4_hdmi.c
+++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
@@ -775,6 +775,51 @@ static void vc4_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
        spin_unlock_irqrestore(&vc4_hdmi->hw_lock, flags);
 }
 
+/*
+ * If we need to output Full Range RGB, then use the unity matrix
+ *
+ * [ 1      0      0      0]
+ * [ 0      1      0      0]
+ * [ 0      0      1      0]
+ *
+ * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
+ */
+static const u16 vc5_hdmi_csc_full_rgb_unity[3][4] = {
+       { 0x2000, 0x0000, 0x0000, 0x0000 },
+       { 0x0000, 0x2000, 0x0000, 0x0000 },
+       { 0x0000, 0x0000, 0x2000, 0x0000 },
+};
+
+/*
+ * CEA VICs other than #1 require limited range RGB output unless
+ * overridden by an AVI infoframe. Apply a colorspace conversion to
+ * squash 0-255 down to 16-235. The matrix here is:
+ *
+ * [ 0.8594 0      0      16]
+ * [ 0      0.8594 0      16]
+ * [ 0      0      0.8594 16]
+ *
+ * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
+ */
+static const u16 vc5_hdmi_csc_full_rgb_to_limited_rgb[3][4] = {
+       { 0x1b80, 0x0000, 0x0000, 0x0400 },
+       { 0x0000, 0x1b80, 0x0000, 0x0400 },
+       { 0x0000, 0x0000, 0x1b80, 0x0400 },
+};
+
+static void vc5_hdmi_set_csc_coeffs(struct vc4_hdmi *vc4_hdmi,
+                                   const u16 coeffs[3][4])
+{
+       lockdep_assert_held(&vc4_hdmi->hw_lock);
+
+       HDMI_WRITE(HDMI_CSC_12_11, (coeffs[0][1] << 16) | coeffs[0][0]);
+       HDMI_WRITE(HDMI_CSC_14_13, (coeffs[0][3] << 16) | coeffs[0][2]);
+       HDMI_WRITE(HDMI_CSC_22_21, (coeffs[1][1] << 16) | coeffs[1][0]);
+       HDMI_WRITE(HDMI_CSC_24_23, (coeffs[1][3] << 16) | coeffs[1][2]);
+       HDMI_WRITE(HDMI_CSC_32_31, (coeffs[2][1] << 16) | coeffs[2][0]);
+       HDMI_WRITE(HDMI_CSC_34_33, (coeffs[2][3] << 16) | coeffs[2][2]);
+}
+
 static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
                               const struct drm_display_mode *mode)
 {
@@ -786,35 +831,10 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 
        HDMI_WRITE(HDMI_VEC_INTERFACE_XBAR, 0x354021);
 
-       if (!vc4_hdmi_is_full_range_rgb(vc4_hdmi, mode)) {
-               /* CEA VICs other than #1 requre limited range RGB
-                * output unless overridden by an AVI infoframe.
-                * Apply a colorspace conversion to squash 0-255 down
-                * to 16-235.  The matrix here is:
-                *
-                * [ 0.8594 0      0      16]
-                * [ 0      0.8594 0      16]
-                * [ 0      0      0.8594 16]
-                * [ 0      0      0       1]
-                * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
-                */
-               HDMI_WRITE(HDMI_CSC_12_11, (0x0000 << 16) | 0x1b80);
-               HDMI_WRITE(HDMI_CSC_14_13, (0x0400 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_22_21, (0x1b80 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_24_23, (0x0400 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_32_31, (0x0000 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_34_33, (0x0400 << 16) | 0x1b80);
-       } else {
-               /* Still use the matrix for full range, but make it unity.
-                * Matrix is signed 2p13 fixed point, with signed 9p6 offsets
-                */
-               HDMI_WRITE(HDMI_CSC_12_11, (0x0000 << 16) | 0x2000);
-               HDMI_WRITE(HDMI_CSC_14_13, (0x0000 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_22_21, (0x2000 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_24_23, (0x0000 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_32_31, (0x0000 << 16) | 0x0000);
-               HDMI_WRITE(HDMI_CSC_34_33, (0x0000 << 16) | 0x2000);
-       }
+       if (!vc4_hdmi_is_full_range_rgb(vc4_hdmi, mode))
+               vc5_hdmi_set_csc_coeffs(vc4_hdmi, vc5_hdmi_csc_full_rgb_to_limited_rgb);
+       else
+               vc5_hdmi_set_csc_coeffs(vc4_hdmi, vc5_hdmi_csc_full_rgb_unity);
 
        HDMI_WRITE(HDMI_CSC_CTL, csc_ctl);