[PATCH v2 2/2] drm/i915: Add SIZE_HINTS property for cursors

[Ville Syrjala <ville.syrjala@linux.intel.com>]

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

Advertize more suitable cursor sizes via the new SIZE_HINTS
plane property.

We can't really enumerate all supported cursor sizes on
the platforms where the cursor height can vary freely, so
for simplicity we'll just expose all square+POT sizes between
each platform's min and max cursor limits.

Depending on the platform this will give us one of three
results:
- 64x64,128x128,256x256,512x512
- 64x64,128x128,256x256
- 64x64

Cc: Simon Ser <contact@emersion.fr>
Cc: Jonas Ådahl <jadahl@redhat.com>
Cc: Daniel Stone <daniel@fooishbar.org>
Cc: Sameer Lattannavar <sameer.lattannavar@intel.com>
Cc: Sebastian Wick <sebastian.wick@redhat.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Pekka Paalanen <pekka.paalanen@collabora.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 drivers/gpu/drm/i915/display/intel_cursor.c | 24 +++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_cursor.c b/drivers/gpu/drm/i915/display/intel_cursor.c
index f8b33999d43f..49e9b9be2235 100644
--- a/drivers/gpu/drm/i915/display/intel_cursor.c
+++ b/drivers/gpu/drm/i915/display/intel_cursor.c
@@ -823,6 +823,28 @@ static const struct drm_plane_funcs intel_cursor_plane_funcs = {
 	.format_mod_supported = intel_cursor_format_mod_supported,
 };
 
+static void intel_cursor_add_size_hints_property(struct intel_plane *plane)
+{
+	struct drm_i915_private *i915 = to_i915(plane->base.dev);
+	const struct drm_mode_config *config = &i915->drm.mode_config;
+	struct drm_plane_size_hint hints[4];
+	int size, max_size, num_hints = 0;
+
+	max_size = min(config->cursor_width, config->cursor_height);
+
+	/* for simplicity only enumerate the supported square+POT sizes */
+	for (size = 64; size <= max_size; size *= 2) {
+		if (drm_WARN_ON(&i915->drm, num_hints >= ARRAY_SIZE(hints)))
+			break;
+
+		hints[num_hints].width = size;
+		hints[num_hints].height = size;
+		num_hints++;
+	}
+
+	drm_plane_add_size_hints_property(&plane->base, hints, num_hints);
+}
+
 struct intel_plane *
 intel_cursor_plane_create(struct drm_i915_private *dev_priv,
 			  enum pipe pipe)
@@ -881,6 +903,8 @@ intel_cursor_plane_create(struct drm_i915_private *dev_priv,
 						   DRM_MODE_ROTATE_0 |
 						   DRM_MODE_ROTATE_180);
 
+	intel_cursor_add_size_hints_property(cursor);
+
 	zpos = DISPLAY_RUNTIME_INFO(dev_priv)->num_sprites[pipe] + 1;
 	drm_plane_create_zpos_immutable_property(&cursor->base, zpos);
 
-- 
2.43.0