drm/tegra: hdmi: Enable audio over HDMI

In order to use the HDA codec to forward audio data to the HDMI codec it
needs the ELD that is parsed from the monitor's EDID.

Also implement an interoperability mechanism between the HDA controller
and the HDMI codec. This uses vendor-defined scratch registers to pass
data from the HDMI codec driver to the HDMI driver (that implements the
receiving end of the HDMI codec). A custom format is used to pass audio
sample rate and channel count to the HDMI driver.
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/hdmi.h

@@ -468,9 +468,20 @@
 #define HDMI_NV_PDISP_KEY_SKEY_INDEX				0xa3
 
 #define HDMI_NV_PDISP_SOR_AUDIO_CNTRL0				0xac
-#define AUDIO_CNTRL0_INJECT_NULLSMPL (1 << 29)
+#define  SOR_AUDIO_CNTRL0_SOURCE_SELECT_AUTO	(0 << 20)
+#define  SOR_AUDIO_CNTRL0_SOURCE_SELECT_SPDIF	(1 << 20)
+#define  SOR_AUDIO_CNTRL0_SOURCE_SELECT_HDAL	(2 << 20)
+#define  SOR_AUDIO_CNTRL0_INJECT_NULLSMPL	(1 << 29)
+#define HDMI_NV_PDISP_SOR_AUDIO_SPARE0				0xae
+#define  SOR_AUDIO_SPARE0_HBR_ENABLE		(1 << 27)
+#define HDMI_NV_PDISP_SOR_AUDIO_HDA_CODEC_SCRATCH0		0xba
+#define  SOR_AUDIO_HDA_CODEC_SCRATCH0_VALID	(1 << 30)
+#define  SOR_AUDIO_HDA_CODEC_SCRATCH0_FMT_MASK	0xffff
+#define HDMI_NV_PDISP_SOR_AUDIO_HDA_CODEC_SCRATCH1		0xbb
 #define HDMI_NV_PDISP_SOR_AUDIO_HDA_ELD_BUFWR			0xbc
 #define HDMI_NV_PDISP_SOR_AUDIO_HDA_PRESENSE			0xbd
+#define  SOR_AUDIO_HDA_PRESENSE_VALID		(1 << 1)
+#define  SOR_AUDIO_HDA_PRESENSE_PRESENT		(1 << 0)
 
 #define HDMI_NV_PDISP_SOR_AUDIO_AVAL_0320    0xbf
 #define HDMI_NV_PDISP_SOR_AUDIO_AVAL_0441    0xc0
@@ -481,6 +492,14 @@
 #define HDMI_NV_PDISP_SOR_AUDIO_AVAL_1920    0xc5
 #define HDMI_NV_PDISP_SOR_AUDIO_AVAL_DEFAULT 0xc5
 
+#define HDMI_NV_PDISP_INT_STATUS			0xcc
+#define  INT_SCRATCH		(1 << 3)
+#define  INT_CP_REQUEST		(1 << 2)
+#define  INT_CODEC_SCRATCH1	(1 << 1)
+#define  INT_CODEC_SCRATCH0	(1 << 0)
+#define HDMI_NV_PDISP_INT_MASK				0xcd
+#define HDMI_NV_PDISP_INT_ENABLE			0xce
+
 #define HDMI_NV_PDISP_SOR_IO_PEAK_CURRENT		0xd1
 #define PEAK_CURRENT_LANE0(x) (((x) & 0x7f) <<  0)
 #define PEAK_CURRENT_LANE1(x) (((x) & 0x7f) <<  8)

drivers/gpu/drm/tegra/output.c

@@ -36,6 +36,7 @@ int tegra_output_connector_get_modes(struct drm_connector *connector)
 
 	if (edid) {
 		err = drm_add_edid_modes(connector, edid);
+		drm_edid_to_eld(connector, edid);
 		kfree(edid);
 	}