[alsa-devel] [PATCH 2/7] drm/i915: add DisplayPort amp unmute for LPE audio mode

[Takashi Iwai]

From: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>

Enable unmute/mute amp notification. This doesn't seem to affect
HDMI support so this is done unconditionally.

An earlier version of this patch set a chicken bit at address 0x62F38
prior to the mute/unmute but this register doesn't seem to do anything
so this phase was removed.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Signed-off-by: Takashi Iwai <tiwai at suse.de>
---
 drivers/gpu/drm/i915/i915_reg.h        | 10 ++++++++++
 drivers/gpu/drm/i915/intel_lpe_audio.c | 17 +++++++++++++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a9ffc8df241b..8fcc80cb864b 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2061,6 +2061,16 @@ enum skl_disp_power_wells {
 #define I915_HDMI_LPE_AUDIO_BASE	(VLV_DISPLAY_BASE + 0x65000)
 #define I915_HDMI_LPE_AUDIO_SIZE	0x1000
 
+/* DisplayPort Audio w/ LPE */
+#define VLV_AUD_PORT_EN_B_DBG		(VLV_DISPLAY_BASE + 0x62F20)
+#define VLV_AUD_PORT_EN_C_DBG		(VLV_DISPLAY_BASE + 0x62F30)
+#define VLV_AUD_PORT_EN_D_DBG		(VLV_DISPLAY_BASE + 0x62F34)
+#define VLV_AUD_PORT_EN_DBG(port)	_MMIO_PORT3((port) - PORT_B,	   \
+						    VLV_AUD_PORT_EN_B_DBG, \
+						    VLV_AUD_PORT_EN_C_DBG, \
+						    VLV_AUD_PORT_EN_D_DBG)
+#define VLV_AMP_MUTE		        (1 << 1)
+
 #define GEN6_BSD_RNCID			_MMIO(0x12198)
 
 #define GEN7_FF_THREAD_MODE		_MMIO(0x20a0)
diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
index 245523e14418..f95624a46f27 100644
--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
+++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
@@ -337,15 +337,25 @@ void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
 {
 	unsigned long irq_flags;
 	struct intel_hdmi_lpe_audio_pdata *pdata = NULL;
+	u32 audio_enable;
+	i915_reg_t mmio;
 
 	if (!HAS_LPE_AUDIO(dev_priv))
 		return;
 
+	if (port == PORT_A) {
+		DRM_ERROR("PORT_A is not valid for HDMI/DP usages\n");
+		return;
+	}
+
 	pdata = dev_get_platdata(
 		&(dev_priv->lpe_audio.platdev->dev));
 
 	spin_lock_irqsave(&pdata->lpe_audio_slock, irq_flags);
 
+	mmio = VLV_AUD_PORT_EN_DBG(port);
+	audio_enable = I915_READ(mmio);
+
 	if (eld != NULL) {
 		memcpy(pdata->eld.eld_data, eld,
 			HDMI_MAX_ELD_BYTES);
@@ -357,11 +367,18 @@ void intel_lpe_audio_notify(struct drm_i915_private *dev_priv,
 			pdata->tmds_clock_speed = tmds_clk_speed;
 		if (link_rate)
 			pdata->link_rate = link_rate;
+
+		/* Unmute the amp for both DP and HDMI */
+		I915_WRITE(mmio, audio_enable & ~VLV_AMP_MUTE);
+
 	} else {
 		memset(pdata->eld.eld_data, 0,
 			HDMI_MAX_ELD_BYTES);
 		pdata->hdmi_connected = false;
 		pdata->dp_output = false;
+
+		/* Mute the amp for both DP and HDMI */
+		I915_WRITE(mmio, audio_enable | VLV_AMP_MUTE);
 	}
 
 	if (pdata->notify_audio_lpe)
-- 
2.11.0