[Intel-gfx] [PATCH-V3 1/2] drm/i915/audio: add codec wakeup override enabled/disable callback

[han.lu at intel.com]

From: "Lu, Han" <han.lu at intel.com>

Add support for enabling codec wakeup override signal to allow
re-enumeration of the controller on SKL after resume from low power state.

v3 by Jani: Simplify to only support toggling the appropriate chicken bit.

Signed-off-by: Lu, Han <han.lu at intel.com>
Signed-off-by: Jani Nikula <jani.nikula at intel.com>

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 36805b6..435c372 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -6881,6 +6881,9 @@ enum skl_disp_power_wells {
 #define   AUDIO_CP_READY(trans)		((1 << 1) << ((trans) * 4))
 #define   AUDIO_ELD_VALID(trans)	((1 << 0) << ((trans) * 4))
 
+#define HSW_AUD_CHICKENBIT			0x65f10
+#define   SKL_AUD_CODEC_WAKE_SIGNAL		(1 << 15)
+
 /* HSW Power Wells */
 #define HSW_PWR_WELL_BIOS			0x45400 /* CTL1 */
 #define HSW_PWR_WELL_DRIVER			0x45404 /* CTL2 */
diff --git a/drivers/gpu/drm/i915/intel_audio.c b/drivers/gpu/drm/i915/intel_audio.c
index f72e93a..ceb2328 100644
--- a/drivers/gpu/drm/i915/intel_audio.c
+++ b/drivers/gpu/drm/i915/intel_audio.c
@@ -474,6 +474,32 @@ static void i915_audio_component_put_power(struct device *dev)
 	intel_display_power_put(dev_to_i915(dev), POWER_DOMAIN_AUDIO);
 }
 
+static void i915_audio_component_codec_wake_override(struct device *dev,
+						     bool enable)
+{
+	struct drm_i915_private *dev_priv = dev_to_i915(dev);
+	u32 tmp;
+
+	if (!IS_SKYLAKE(dev_priv))
+		return;
+
+	/*
+	 * Enable/disable generating the codec wake signal, overriding the
+	 * internal logic to generate the codec wake to controller.
+	 */
+	tmp = I915_READ(HSW_AUD_CHICKENBIT);
+	tmp &= ~SKL_AUD_CODEC_WAKE_SIGNAL;
+	I915_WRITE(HSW_AUD_CHICKENBIT, tmp);
+	usleep_range(1000, 1500);
+
+	if (enable) {
+		tmp = I915_READ(HSW_AUD_CHICKENBIT);
+		tmp |= SKL_AUD_CODEC_WAKE_SIGNAL;
+		I915_WRITE(HSW_AUD_CHICKENBIT, tmp);
+		usleep_range(1000, 1500);
+	}
+}
+
 /* Get CDCLK in kHz  */
 static int i915_audio_component_get_cdclk_freq(struct device *dev)
 {
@@ -495,6 +521,7 @@ static const struct i915_audio_component_ops i915_audio_component_ops = {
 	.owner		= THIS_MODULE,
 	.get_power	= i915_audio_component_get_power,
 	.put_power	= i915_audio_component_put_power,
+	.codec_wake_override = i915_audio_component_codec_wake_override,
 	.get_cdclk_freq	= i915_audio_component_get_cdclk_freq,
 };
 
diff --git a/include/drm/i915_component.h b/include/drm/i915_component.h
index 3e2f22e..c9a8b64 100644
--- a/include/drm/i915_component.h
+++ b/include/drm/i915_component.h
@@ -31,6 +31,7 @@ struct i915_audio_component {
 		struct module *owner;
 		void (*get_power)(struct device *);
 		void (*put_power)(struct device *);
+		void (*codec_wake_override)(struct device *, bool enable);
 		int (*get_cdclk_freq)(struct device *);
 	} *ops;
 };
-- 
1.9.1