[alsa-devel] [RFC PATCH 4/5] drm: i915: add DisplayPort amp unmute for LPE audio mode

[Pierre-Louis Bossart]

Enable chicken bit on LPE mode setup and unmute amp on
notification

FIXME: should these two phases done somewhere else?

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h        | 12 ++++++++++++
 drivers/gpu/drm/i915/intel_lpe_audio.c | 27 +++++++++++++++++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index a9ffc8d..ee90f64 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2061,6 +2061,18 @@ 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 CHICKEN_BIT_DBG_ENABLE		(1 << 0)
+#define AMP_UNMUTE		        (1 << 1)
+#define AUD_CHICKEN_BIT_REG		0x62F38
+#define AUD_PORT_EN_B_DBG		0x62F20
+#define AUD_PORT_EN_C_DBG		0x62F28
+#define AUD_PORT_EN_D_DBG		0x62F2C
+#define VLV_AUD_CHICKEN_BIT_REG		_MMIO(VLV_DISPLAY_BASE + AUD_CHICKEN_BIT_REG)
+#define VLV_AUD_PORT_EN_B_DBG		_MMIO(VLV_DISPLAY_BASE + AUD_PORT_EN_B_DBG)
+#define VLV_AUD_PORT_EN_C_DBG		_MMIO(VLV_DISPLAY_BASE + AUD_PORT_EN_C_DBG)
+#define VLV_AUD_PORT_EN_D_DBG		_MMIO(VLV_DISPLAY_BASE + AUD_PORT_EN_D_DBG)
+
 #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 245523e..b3134ef 100644
--- a/drivers/gpu/drm/i915/intel_lpe_audio.c
+++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
@@ -248,6 +248,15 @@ static int lpe_audio_setup(struct drm_i915_private *dev_priv)
 		goto err_free_irq;
 	}
 
+	/* Enable DPAudio debug bits by default */
+	if (IS_CHERRYVIEW(dev_priv)) {
+		u32 chicken_bit;
+
+		chicken_bit = I915_READ(VLV_AUD_CHICKEN_BIT_REG);
+		I915_WRITE(VLV_AUD_CHICKEN_BIT_REG,
+			   chicken_bit | CHICKEN_BIT_DBG_ENABLE);
+	}
+
 	return 0;
 err_free_irq:
 	irq_free_desc(dev_priv->lpe_audio.irq);
@@ -357,6 +366,24 @@ 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;
+
+		if (dp_output) { /* unmute the amp */
+			u32 audio_enable;
+
+			if (port == PORT_B) {
+				audio_enable = I915_READ(VLV_AUD_PORT_EN_B_DBG);
+				I915_WRITE(VLV_AUD_PORT_EN_B_DBG,
+					   audio_enable & ~AMP_UNMUTE);
+			} else if (port == PORT_C) {
+				audio_enable = I915_READ(VLV_AUD_PORT_EN_C_DBG);
+				I915_WRITE(VLV_AUD_PORT_EN_C_DBG,
+					   audio_enable & ~AMP_UNMUTE);
+			} else if (port == PORT_D) {
+				audio_enable = I915_READ(VLV_AUD_PORT_EN_D_DBG);
+				I915_WRITE(VLV_AUD_PORT_EN_D_DBG,
+					   audio_enable & ~AMP_UNMUTE);
+			}
+		}
 	} else {
 		memset(pdata->eld.eld_data, 0,
 			HDMI_MAX_ELD_BYTES);
-- 
2.7.4