drm/i915: set HDMI pixel clock in audio configuration

The HDMI audio expects HDMI pixel clock to be set in the audio
configuration. We've currently just set 0, using 25.2 / 1.001 kHz
frequency, which fails with some modes.

v2: Now with a commit message.

Reference: http://mid.gmane.org/CAGpEb3Ep1LRZETPxHGRfBDqr5Ts2tAc8gCukWwugUf1U5NYv1g@mail.gmail.com
Reference: http://mid.gmane.org/20130206213533.GA16367@hardeman.nu
Reported-by: David Härdeman <david@hardeman.nu>
Reported-by: Jasper Smet <josbeir@gmail.com>
Tested-by: Jasper Smet <josbeir@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_reg.h

@@ -4901,7 +4901,17 @@
 #define   AUD_CONFIG_LOWER_N_SHIFT		4
 #define   AUD_CONFIG_LOWER_N_VALUE		(0xfff << 4)
 #define   AUD_CONFIG_PIXEL_CLOCK_HDMI_SHIFT	16
-#define   AUD_CONFIG_PIXEL_CLOCK_HDMI		(0xf << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_MASK	(0xf << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_25175	(0 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_25200	(1 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_27000	(2 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_27027	(3 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_54000	(4 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_54054	(5 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_74176	(6 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_74250	(7 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_148352	(8 << 16)
+#define   AUD_CONFIG_PIXEL_CLOCK_HDMI_148500	(9 << 16)
 #define   AUD_CONFIG_DISABLE_NCTS		(1 << 3)
 
 /* HSW Audio */

drivers/gpu/drm/i915/intel_display.c

@@ -6723,6 +6723,44 @@ static int intel_crtc_mode_set(struct drm_crtc *crtc,
 	return 0;
 }
 
+static struct {
+	int clock;
+	u32 config;
+} hdmi_audio_clock[] = {
+	{ DIV_ROUND_UP(25200 * 1000, 1001), AUD_CONFIG_PIXEL_CLOCK_HDMI_25175 },
+	{ 25200, AUD_CONFIG_PIXEL_CLOCK_HDMI_25200 }, /* default per bspec */
+	{ 27000, AUD_CONFIG_PIXEL_CLOCK_HDMI_27000 },
+	{ 27000 * 1001 / 1000, AUD_CONFIG_PIXEL_CLOCK_HDMI_27027 },
+	{ 54000, AUD_CONFIG_PIXEL_CLOCK_HDMI_54000 },
+	{ 54000 * 1001 / 1000, AUD_CONFIG_PIXEL_CLOCK_HDMI_54054 },
+	{ DIV_ROUND_UP(74250 * 1000, 1001), AUD_CONFIG_PIXEL_CLOCK_HDMI_74176 },
+	{ 74250, AUD_CONFIG_PIXEL_CLOCK_HDMI_74250 },
+	{ DIV_ROUND_UP(148500 * 1000, 1001), AUD_CONFIG_PIXEL_CLOCK_HDMI_148352 },
+	{ 148500, AUD_CONFIG_PIXEL_CLOCK_HDMI_148500 },
+};
+
+/* get AUD_CONFIG_PIXEL_CLOCK_HDMI_* value for mode */
+static u32 audio_config_hdmi_pixel_clock(struct drm_display_mode *mode)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(hdmi_audio_clock); i++) {
+		if (mode->clock == hdmi_audio_clock[i].clock)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(hdmi_audio_clock)) {
+		DRM_DEBUG_KMS("HDMI audio pixel clock setting for %d not found, falling back to defaults\n", mode->clock);
+		i = 1;
+	}
+
+	DRM_DEBUG_KMS("Configuring HDMI audio for pixel clock %d (0x%08x)\n",
+		      hdmi_audio_clock[i].clock,
+		      hdmi_audio_clock[i].config);
+
+	return hdmi_audio_clock[i].config;
+}
+
 static bool intel_eld_uptodate(struct drm_connector *connector,
 			       int reg_eldv, uint32_t bits_eldv,
 			       int reg_elda, uint32_t bits_elda,
@@ -6848,8 +6886,9 @@ static void haswell_write_eld(struct drm_connector *connector,
 		DRM_DEBUG_DRIVER("ELD: DisplayPort detected\n");
 		eld[5] |= (1 << 2);	/* Conn_Type, 0x1 = DisplayPort */
 		I915_WRITE(aud_config, AUD_CONFIG_N_VALUE_INDEX); /* 0x1 = DP */
-	} else
-		I915_WRITE(aud_config, 0);
+	} else {
+		I915_WRITE(aud_config, audio_config_hdmi_pixel_clock(mode));
+	}
 
 	if (intel_eld_uptodate(connector,
 			       aud_cntrl_st2, eldv,
@@ -6927,8 +6966,9 @@ static void ironlake_write_eld(struct drm_connector *connector,
 		DRM_DEBUG_DRIVER("ELD: DisplayPort detected\n");
 		eld[5] |= (1 << 2);	/* Conn_Type, 0x1 = DisplayPort */
 		I915_WRITE(aud_config, AUD_CONFIG_N_VALUE_INDEX); /* 0x1 = DP */
-	} else
-		I915_WRITE(aud_config, 0);
+	} else {
+		I915_WRITE(aud_config, audio_config_hdmi_pixel_clock(mode));
+	}
 
 	if (intel_eld_uptodate(connector,
 			       aud_cntrl_st2, eldv,