drm/i915: set AUD_CONFIG N_value_index for DisplayPort

It should be programmed to "0" for HDMI or "1" for DisplayPort.

This enables DisplayPort audio for

- HP EliteBook 8460p
  (whose BIOS does not set the N_value_index bit for us)

- DisplayPort monitor hot plugged after boot
  (otherwise most BIOS will fill the N_value_index bit for us)

Tested-by: Robert Lemaire <rlemaire@suse.com>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index bbad788..f4daa6e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3742,4 +3742,16 @@
  */
 #define GEN7_SO_WRITE_OFFSET(n)                (0x5280 + (n) * 4)
 
+#define IBX_AUD_CONFIG_A                       0xe2000
+#define CPT_AUD_CONFIG_A                       0xe5000
+#define   AUD_CONFIG_N_VALUE_INDEX             (1 << 29)
+#define   AUD_CONFIG_N_PROG_ENABLE             (1 << 28)
+#define   AUD_CONFIG_UPPER_N_SHIFT             20
+#define   AUD_CONFIG_UPPER_N_VALUE             (0xff << 20)
+#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_DISABLE_NCTS              (1 << 3)
+
 #endif /* _I915_REG_H_ */

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index ebb3452..0770671 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6141,15 +6141,18 @@ static void ironlake_write_eld(struct drm_connector *connector,
        uint32_t i;
        int len;
        int hdmiw_hdmiedid;
+       int aud_config;
        int aud_cntl_st;
        int aud_cntrl_st2;
 
        if (HAS_PCH_IBX(connector->dev)) {
                hdmiw_hdmiedid = IBX_HDMIW_HDMIEDID_A;
+               aud_config = IBX_AUD_CONFIG_A;
                aud_cntl_st = IBX_AUD_CNTL_ST_A;
                aud_cntrl_st2 = IBX_AUD_CNTL_ST2;
        } else {
                hdmiw_hdmiedid = CPT_HDMIW_HDMIEDID_A;
+               aud_config = CPT_AUD_CONFIG_A;
                aud_cntl_st = CPT_AUD_CNTL_ST_A;
                aud_cntrl_st2 = CPT_AUD_CNTRL_ST2;
        }
@@ -6157,6 +6160,7 @@ static void ironlake_write_eld(struct drm_connector *connector,
        i = to_intel_crtc(crtc)->pipe;
        hdmiw_hdmiedid += i * 0x100;
        aud_cntl_st += i * 0x100;
+       aud_config += i * 0x100;
 
        DRM_DEBUG_DRIVER("ELD on pipe %c\n", pipe_name(i));
 
@@ -6176,7 +6180,9 @@ static void ironlake_write_eld(struct drm_connector *connector,
        if (intel_pipe_has_type(crtc, INTEL_OUTPUT_DISPLAYPORT)) {
                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);
 
        if (intel_eld_uptodate(connector,
                               aud_cntrl_st2, eldv,