[PATCH] drm/i915: Intel-specific primary plane handling (v4)

[Matt Roper <matthew.d.roper@intel.com>]

Intel hardware allows the primary plane to be disabled independently of
the CRTC.  Provide custom primary plane handling to allow this.

v4:
 - Don't add a primary_plane field to intel_crtc; that was left over
   from a much earlier iteration of this patch series, but is no longer
   needed/used now that the DRM core primary plane support has been
   merged.
v3:
 - Provide gen-specific primary plane format lists (suggested by Daniel
   Vetter).
 - If the primary plane is already enabled, go ahead and just call the
   primary plane helper to do the update (suggested by Daniel Vetter).
 - Don't try to disable the primary plane on destruction; the DRM layer
   should have already taken care of this for us.
v2:
 - Unpin fb properly on primary plane disable
 - Provide an Intel-specific set of primary plane formats
 - Additional sanity checks on setplane (in line with the checks
   currently being done by the DRM core primary plane helper)

Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
---
 drivers/gpu/drm/i915/intel_display.c | 197 ++++++++++++++++++++++++++++++++++-
 1 file changed, 195 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1390ab5..3e4d36a 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -39,8 +39,35 @@
 #include "i915_trace.h"
 #include <drm/drm_dp_helper.h>
 #include <drm/drm_crtc_helper.h>
+#include <drm/drm_plane_helper.h>
+#include <drm/drm_rect.h>
 #include <linux/dma_remapping.h>
 
+/* Primary plane formats supported by all gen */
+#define COMMON_PRIMARY_FORMATS \
+	DRM_FORMAT_C8, \
+	DRM_FORMAT_RGB565, \
+	DRM_FORMAT_XRGB8888, \
+	DRM_FORMAT_ARGB8888
+
+/* Primary plane formats for gen <= 3 */
+const static uint32_t intel_primary_formats_gen3[] = {
+	COMMON_PRIMARY_FORMATS,
+	DRM_FORMAT_XRGB1555,
+	DRM_FORMAT_ARGB1555,
+};
+
+/* Primary plane formats for gen >= 4 */
+const static uint32_t intel_primary_formats_gen4[] = {
+	COMMON_PRIMARY_FORMATS, \
+	DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_ABGR8888,
+	DRM_FORMAT_XRGB2101010,
+	DRM_FORMAT_ARGB2101010,
+	DRM_FORMAT_XBGR2101010,
+	DRM_FORMAT_ABGR2101010,
+};
+
 static void intel_increase_pllclock(struct drm_crtc *crtc);
 static void intel_crtc_update_cursor(struct drm_crtc *crtc, bool on);
 
@@ -10556,17 +10583,183 @@ static void intel_shared_dpll_init(struct drm_device *dev)
 	BUG_ON(dev_priv->num_shared_dpll > I915_NUM_PLLS);
 }
 
+static int
+intel_primary_plane_setplane(struct drm_plane *plane, struct drm_crtc *crtc,
+			     struct drm_framebuffer *fb, int crtc_x, int crtc_y,
+			     unsigned int crtc_w, unsigned int crtc_h,
+			     uint32_t src_x, uint32_t src_y,
+			     uint32_t src_w, uint32_t src_h)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
+	struct drm_framebuffer *tmpfb;
+	struct drm_rect dest = {
+		.x1 = crtc_x,
+		.y1 = crtc_y,
+		.x2 = crtc_x + crtc_w,
+		.y2 = crtc_y + crtc_h,
+	};
+	struct drm_rect clip = {
+		.x2 = crtc->mode.hdisplay,
+		.y2 = crtc->mode.vdisplay,
+	};
+	int ret;
+
+	/*
+	 * At the moment we use the same set of setplane restrictions as the
+	 * DRM primary plane helper, so go ahead and just call the helper if
+	 * the primary plane is already enabled.  We only need to take special
+	 * action if the primary plane is disabled (something i915 can do but
+	 * the generic helper can't).
+	 */
+	if (intel_crtc->primary_enabled)
+		return drm_primary_helper_update(plane, crtc, fb,
+						 crtc_x, crtc_y,
+						 crtc_w, crtc_h,
+						 src_x, src_y,
+						 src_w, src_h);
+
+	/* setplane API takes shifted source rectangle values; unshift them */
+	src_x >>= 16;
+	src_y >>= 16;
+	src_w >>= 16;
+	src_h >>= 16;
+
+	/*
+	 * Current hardware can't reposition the primary plane or scale it
+	 * (although this could change in the future).
+	 */
+	drm_rect_intersect(&dest, &clip);
+	if (dest.x1 != 0 || dest.y1 != 0 ||
+	    dest.x2 != crtc->mode.hdisplay || dest.y2 != crtc->mode.vdisplay) {
+		DRM_DEBUG_KMS("Primary plane must cover entire CRTC\n");
+		return -EINVAL;
+	}
+
+	if (crtc_w != src_w || crtc_h != src_h) {
+		DRM_DEBUG_KMS("Can't scale primary plane\n");
+		return -EINVAL;
+	}
+
+	/* Primary planes are locked to their owning CRTC */
+	if (plane->possible_crtcs != drm_crtc_mask(crtc)) {
+		DRM_DEBUG_KMS("Cannot change primary plane CRTC\n");
+		return -EINVAL;
+	}
+
+	/* Framebuffer must be big enough to cover entire plane */
+	ret = drm_crtc_check_viewport(crtc, crtc_x, crtc_y, &crtc->mode, fb);
+	if (ret)
+		return ret;
+
+	/*
+	 * pipe_set_base() adjusts crtc->primary->fb; however the DRM setplane
+	 * code that called us expects to handle the framebuffer update and
+	 * reference counting; save and restore the current fb before
+	 * calling it.
+	 */
+	tmpfb = plane->fb;
+	ret = intel_pipe_set_base(crtc, src_x, src_y, fb);
+	if (ret)
+		return ret;
+	plane->fb = tmpfb;
+
+	intel_enable_primary_hw_plane(dev_priv, intel_crtc->plane,
+				      intel_crtc->pipe);
+
+	return 0;
+}
+
+static int
+intel_primary_plane_disable(struct drm_plane *plane)
+{
+	struct drm_device *dev = plane->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_plane *intel_plane = to_intel_plane(plane);
+	struct intel_crtc *intel_crtc;
+
+	if (!plane->fb)
+		return 0;
+
+	if (WARN_ON(!plane->crtc))
+		return -EINVAL;
+
+	intel_crtc = to_intel_crtc(plane->crtc);
+	if (intel_crtc->primary_enabled)
+		intel_disable_primary_hw_plane(dev_priv, intel_plane->plane,
+					       intel_plane->pipe);
+
+	/*
+	 * N.B. The DRM setplane code will update the plane->fb pointer after
+	 * we finish here.
+	 */
+	intel_unpin_fb_obj(to_intel_framebuffer(plane->fb)->obj);
+
+	return 0;
+}
+
+static void intel_primary_plane_destroy(struct drm_plane *plane)
+{
+	struct intel_plane *intel_plane = to_intel_plane(plane);
+	drm_plane_cleanup(plane);
+	kfree(intel_plane);
+}
+
+static const struct drm_plane_funcs intel_primary_plane_funcs = {
+	.update_plane = intel_primary_plane_setplane,
+	.disable_plane = intel_primary_plane_disable,
+	.destroy = intel_primary_plane_destroy,
+};
+
+static struct drm_plane *intel_primary_plane_create(struct drm_device *dev,
+						    int pipe)
+{
+	struct intel_plane *primary;
+	const uint32_t *intel_primary_formats;
+	int num_formats;
+
+	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
+	if (primary == NULL)
+		return NULL;
+
+	primary->can_scale = false;
+	primary->pipe = pipe;
+	primary->plane = pipe;
+
+	if (INTEL_INFO(dev)->gen <= 3) {
+		intel_primary_formats = intel_primary_formats_gen3;
+		num_formats = ARRAY_SIZE(intel_primary_formats_gen3);
+	} else {
+		intel_primary_formats = intel_primary_formats_gen4;
+		num_formats = ARRAY_SIZE(intel_primary_formats_gen4);
+	}
+
+	drm_plane_init(dev, &primary->base, 0,
+		       &intel_primary_plane_funcs, intel_primary_formats,
+		       num_formats, DRM_PLANE_TYPE_PRIMARY);
+	return &primary->base;
+}
+
 static void intel_crtc_init(struct drm_device *dev, int pipe)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_crtc *intel_crtc;
-	int i;
+	struct drm_plane *primary;
+	int i, ret;
 
 	intel_crtc = kzalloc(sizeof(*intel_crtc), GFP_KERNEL);
 	if (intel_crtc == NULL)
 		return;
 
-	drm_crtc_init(dev, &intel_crtc->base, &intel_crtc_funcs);
+	primary = intel_primary_plane_create(dev, pipe);
+	ret = drm_crtc_init_with_planes(dev, &intel_crtc->base, primary,
+					NULL, &intel_crtc_funcs);
+	if (ret) {
+		drm_crtc_cleanup(&intel_crtc->base);
+		kfree(intel_crtc);
+		return;
+	}
 
 	drm_mode_crtc_set_gamma_size(&intel_crtc->base, 256);
 	for (i = 0; i < 256; i++) {
-- 
1.8.5.1