drm/vc4: hdmi: Replace CSC_CTL hardcoded value by defines

On BCM2711, the HDMI_CSC_CTL register value has been hardcoded to an
opaque value. Let's replace it with properly defined values.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220120151625.594595-9-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -779,9 +779,8 @@ static void vc5_hdmi_csc_setup(struct vc4_hdmi *vc4_hdmi,
 			       const struct drm_display_mode *mode)
 {
 	unsigned long flags;
-	u32 csc_ctl;
-
-	csc_ctl = 0x07;	/* RGB_CONVERT_MODE = custom matrix, || USE_RGB_TO_YCBCR */
+	u32 csc_ctl = VC5_MT_CP_CSC_CTL_ENABLE | VC4_SET_FIELD(VC4_HD_CSC_CTL_MODE_CUSTOM,
+							       VC5_MT_CP_CSC_CTL_MODE);
 
 	spin_lock_irqsave(&vc4_hdmi->hw_lock, flags);
 

drivers/gpu/drm/vc4/vc4_regs.h

@@ -774,6 +774,9 @@ enum {
 # define VC4_HD_CSC_CTL_RGB2YCC			BIT(1)
 # define VC4_HD_CSC_CTL_ENABLE			BIT(0)
 
+# define VC5_MT_CP_CSC_CTL_ENABLE		BIT(2)
+# define VC5_MT_CP_CSC_CTL_MODE_MASK		VC4_MASK(1, 0)
+
 # define VC4_DVP_HT_CLOCK_STOP_PIXEL		BIT(1)
 
 /* HVS display list information. */