[PATCH 2/4] drm/i915: Enabling constant alpha drm property

[sagar.a.kamble@intel.com]

From: Sagar Kamble <sagar.a.kamble@intel.com>

This patch enables constant alpha property for Sprite planes.
Client has to set BIT(DRM_BLEND_CONSTANT_ALPHA) | (8 bit alpha value)
for applying constant alpha on a plane. To disable constant alpha,
client has to set BIT(DRM_BLEND_NONE)

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: David Airlie <airlied@linux.ie>
Signed-off-by: Sagar Kamble <sagar.a.kamble@intel.com>
---
 drivers/gpu/drm/i915/i915_dma.c     | 11 ++++++-
 drivers/gpu/drm/i915/i915_drv.h     |  1 +
 drivers/gpu/drm/i915/i915_reg.h     |  2 ++
 drivers/gpu/drm/i915/intel_drv.h    |  7 +++++
 drivers/gpu/drm/i915/intel_sprite.c | 61 ++++++++++++++++++++++++++++++++++++-
 5 files changed, 80 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
index e4d2b9f..286251d 100644
--- a/drivers/gpu/drm/i915/i915_dma.c
+++ b/drivers/gpu/drm/i915/i915_dma.c
@@ -1897,13 +1897,22 @@ int i915_driver_open(struct drm_device *dev, struct drm_file *file)
 void i915_driver_lastclose(struct drm_device * dev)
 {
 	drm_i915_private_t *dev_priv = dev->dev_private;
-
+	struct intel_plane *plane;
 	/* On gen6+ we refuse to init without kms enabled, but then the drm core
 	 * goes right around and calls lastclose. Check for this and don't clean
 	 * up anything. */
 	if (!dev_priv)
 		return;
 
+	if (dev_priv->blend_property) {
+		list_for_each_entry(plane, &dev->mode_config.plane_list, base.head) {
+			plane->blend_param.value = BIT(DRM_BLEND_NONE);
+			drm_object_property_set_value(&plane->base.base,
+						dev_priv->blend_property,
+						plane->blend_param.value);
+		}
+	}
+
 	if (drm_core_check_feature(dev, DRIVER_MODESET)) {
 		intel_fbdev_restore_mode(dev);
 		vga_switcheroo_process_delayed_switch();
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 2a319ba..8a82fb7 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1604,6 +1604,7 @@ typedef struct drm_i915_private {
 
 	struct drm_property *broadcast_rgb_property;
 	struct drm_property *force_audio_property;
+	struct drm_property *blend_property;
 
 	uint32_t hw_context_size;
 	struct list_head context_list;
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index 146609a..292d55d 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -3772,6 +3772,8 @@ enum punit_power_well {
 #define   SPRITE_INT_GAMMA_ENABLE	(1<<13)
 #define   SPRITE_TILED			(1<<10)
 #define   SPRITE_DEST_KEY		(1<<2)
+#define	  SPRITE_CONSTANT_ALPHA_ENABLE  (1<<31)
+#define   SPRITE_CONSTANT_ALPHA_MASK	(0xFF)
 #define _SPRA_LINOFF		0x70284
 #define _SPRA_STRIDE		0x70288
 #define _SPRA_POS		0x7028c
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 4a4c6dd..e33124c 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -405,6 +405,13 @@ struct intel_plane {
 	unsigned int crtc_w, crtc_h;
 	uint32_t src_x, src_y;
 	uint32_t src_w, src_h;
+	union {
+		uint64_t value;
+		struct {
+			unsigned int type;
+			unsigned int factor;
+		} details;
+	} blend_param;
 
 	/* Since we need to change the watermarks before/after
 	 * enabling/disabling the planes, we need to store the parameters here
diff --git a/drivers/gpu/drm/i915/intel_sprite.c b/drivers/gpu/drm/i915/intel_sprite.c
index 9436f18..4c3d2a2 100644
--- a/drivers/gpu/drm/i915/intel_sprite.c
+++ b/drivers/gpu/drm/i915/intel_sprite.c
@@ -51,11 +51,15 @@ vlv_update_plane(struct drm_plane *dplane, struct drm_crtc *crtc,
 	int pipe = intel_plane->pipe;
 	int plane = intel_plane->plane;
 	u32 sprctl;
+	u32 sprconstalpha;
+	unsigned int blend_type, blend_factor;
 	unsigned long sprsurf_offset, linear_offset;
 	int pixel_size = drm_format_plane_cpp(fb->pixel_format, 0);
 
 	sprctl = I915_READ(SPCNTR(pipe, plane));
 
+	sprconstalpha = SPCONSTALPHA(pipe, plane);
+
 	/* Mask out pixel format bits in case we change it */
 	sprctl &= ~SP_PIXFORMAT_MASK;
 	sprctl &= ~SP_YUV_BYTE_ORDER_MASK;
@@ -104,6 +108,23 @@ vlv_update_plane(struct drm_plane *dplane, struct drm_crtc *crtc,
 		break;
 	}
 
+	/* Handle plane alpha and color blending properties */
+	blend_type = intel_plane->blend_param.details.type;
+	blend_factor = intel_plane->blend_param.details.factor;
+
+	switch (blend_type) {
+	case DRM_BLEND_NONE:
+		I915_WRITE(sprconstalpha, ~SPRITE_CONSTANT_ALPHA_ENABLE);
+		break;
+	case DRM_BLEND_CONSTANT_ALPHA:
+		I915_WRITE(sprconstalpha, (blend_factor & SPRITE_CONSTANT_ALPHA_MASK) |
+						SPRITE_CONSTANT_ALPHA_ENABLE);
+		break;
+	default:
+		DRM_DEBUG_DRIVER("%x Blending operation not supported", intel_plane->blend_param.details.type);
+		break;
+	}
+
 	/*
 	 * Enable gamma to match primary/cursor plane behaviour.
 	 * FIXME should be user controllable via propertiesa.
@@ -1011,6 +1032,26 @@ out_unlock:
 	return ret;
 }
 
+static int intel_plane_set_property(struct drm_plane *plane,
+				    struct drm_property *prop,
+				    uint64_t val)
+{
+	struct drm_i915_private *dev_priv = plane->dev->dev_private;
+	struct intel_plane *intel_plane = to_intel_plane(plane);
+	uint64_t old_val;
+	int ret = -ENOENT;
+
+	if (prop == dev_priv->blend_property) {
+		old_val = intel_plane->blend_param.value;
+		intel_plane->blend_param.value = val;
+		ret = intel_plane_restore(plane);
+		if (ret)
+			intel_plane->blend_param.value = old_val;
+	}
+
+	return ret;
+}
+
 int intel_plane_restore(struct drm_plane *plane)
 {
 	struct intel_plane *intel_plane = to_intel_plane(plane);
@@ -1037,6 +1078,7 @@ static const struct drm_plane_funcs intel_plane_funcs = {
 	.update_plane = intel_update_plane,
 	.disable_plane = intel_disable_plane,
 	.destroy = intel_destroy_plane,
+	.set_property = intel_plane_set_property,
 };
 
 static uint32_t ilk_plane_formats[] = {
@@ -1073,6 +1115,7 @@ static uint32_t vlv_plane_formats[] = {
 int
 intel_plane_init(struct drm_device *dev, enum pipe pipe, int plane)
 {
+	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_plane *intel_plane;
 	unsigned long possible_crtcs;
 	const uint32_t *plane_formats;
@@ -1141,13 +1184,29 @@ intel_plane_init(struct drm_device *dev, enum pipe pipe, int plane)
 
 	intel_plane->pipe = pipe;
 	intel_plane->plane = plane;
+	/* Initialize drm properties for plane */
+	intel_plane->blend_param.details.type = BIT(DRM_BLEND_NONE);
+	intel_plane->blend_param.details.factor = 0;
+
 	possible_crtcs = (1 << pipe);
 	ret = drm_plane_init(dev, &intel_plane->base, possible_crtcs,
 			     &intel_plane_funcs,
 			     plane_formats, num_plane_formats,
 			     false);
-	if (ret)
+	if (ret) {
 		kfree(intel_plane);
+		goto out;
+	}
+
+	if (!dev_priv->blend_property)
+		dev_priv->blend_property = drm_mode_create_blend_property(dev,
+							BIT(DRM_BLEND_NONE) |
+							BIT(DRM_BLEND_CONSTANT_ALPHA));
 
+	if (dev_priv->blend_property)
+		drm_object_attach_property(&intel_plane->base.base,
+				dev_priv->blend_property,
+				intel_plane->blend_param.value);
+out:
 	return ret;
 }
-- 
1.8.5