+/* -----------------------------------------------------------------------------
+ * VSP1 Entity Operations
+ */
+
+static void bru_configure(struct vsp1_entity *entity)
+{
+ struct vsp1_pipeline *pipe = to_vsp1_pipeline(&entity->subdev.entity);
+ struct vsp1_bru *bru = to_bru(&entity->subdev);
+ struct v4l2_mbus_framefmt *format;
+ unsigned int flags;
+ unsigned int i;
+
+ format = vsp1_entity_get_pad_format(&bru->entity, bru->entity.config,
+ bru->entity.source_pad);
+
+ /* The hardware is extremely flexible but we have no userspace API to
+ * expose all the parameters, nor is it clear whether we would have use
+ * cases for all the supported modes. Let's just harcode the parameters
+ * to sane default values for now.
+ */
+
+ /* Disable dithering and enable color data normalization unless the
+ * format at the pipeline output is premultiplied.
+ */
+ flags = pipe->output ? pipe->output->format.flags : 0;
+ vsp1_bru_write(bru, VI6_BRU_INCTRL,
+ flags & V4L2_PIX_FMT_FLAG_PREMUL_ALPHA ?
+ 0 : VI6_BRU_INCTRL_NRM);
+
+ /* Set the background position to cover the whole output image and
+ * configure its color.
+ */
+ vsp1_bru_write(bru, VI6_BRU_VIRRPF_SIZE,
+ (format->width << VI6_BRU_VIRRPF_SIZE_HSIZE_SHIFT) |
+ (format->height << VI6_BRU_VIRRPF_SIZE_VSIZE_SHIFT));
+ vsp1_bru_write(bru, VI6_BRU_VIRRPF_LOC, 0);
+
+ vsp1_bru_write(bru, VI6_BRU_VIRRPF_COL, bru->bgcolor |
+ (0xff << VI6_BRU_VIRRPF_COL_A_SHIFT));
+
+ /* Route BRU input 1 as SRC input to the ROP unit and configure the ROP
+ * unit with a NOP operation to make BRU input 1 available as the
+ * Blend/ROP unit B SRC input.
+ */
+ vsp1_bru_write(bru, VI6_BRU_ROP, VI6_BRU_ROP_DSTSEL_BRUIN(1) |
+ VI6_BRU_ROP_CROP(VI6_ROP_NOP) |
+ VI6_BRU_ROP_AROP(VI6_ROP_NOP));
+
+ for (i = 0; i < bru->entity.source_pad; ++i) {
+ bool premultiplied = false;
+ u32 ctrl = 0;
+
+ /* Configure all Blend/ROP units corresponding to an enabled BRU
+ * input for alpha blending. Blend/ROP units corresponding to
+ * disabled BRU inputs are used in ROP NOP mode to ignore the
+ * SRC input.
+ */
+ if (bru->inputs[i].rpf) {
+ ctrl |= VI6_BRU_CTRL_RBC;
+
+ premultiplied = bru->inputs[i].rpf->format.flags
+ & V4L2_PIX_FMT_FLAG_PREMUL_ALPHA;
+ } else {
+ ctrl |= VI6_BRU_CTRL_CROP(VI6_ROP_NOP)
+ | VI6_BRU_CTRL_AROP(VI6_ROP_NOP);
+ }
+
+ /* Select the virtual RPF as the Blend/ROP unit A DST input to
+ * serve as a background color.
+ */
+ if (i == 0)
+ ctrl |= VI6_BRU_CTRL_DSTSEL_VRPF;
+
+ /* Route BRU inputs 0 to 3 as SRC inputs to Blend/ROP units A to
+ * D in that order. The Blend/ROP unit B SRC is hardwired to the
+ * ROP unit output, the corresponding register bits must be set
+ * to 0.
+ */
+ if (i != 1)
+ ctrl |= VI6_BRU_CTRL_SRCSEL_BRUIN(i);
+
+ vsp1_bru_write(bru, VI6_BRU_CTRL(i), ctrl);
+
+ /* Harcode the blending formula to
+ *
+ * DSTc = DSTc * (1 - SRCa) + SRCc * SRCa
+ * DSTa = DSTa * (1 - SRCa) + SRCa
+ *
+ * when the SRC input isn't premultiplied, and to
+ *
+ * DSTc = DSTc * (1 - SRCa) + SRCc
+ * DSTa = DSTa * (1 - SRCa) + SRCa
+ *
+ * otherwise.
+ */
+ vsp1_bru_write(bru, VI6_BRU_BLD(i),
+ VI6_BRU_BLD_CCMDX_255_SRC_A |
+ (premultiplied ? VI6_BRU_BLD_CCMDY_COEFY :
+ VI6_BRU_BLD_CCMDY_SRC_A) |
+ VI6_BRU_BLD_ACMDX_255_SRC_A |
+ VI6_BRU_BLD_ACMDY_COEFY |
+ (0xff << VI6_BRU_BLD_COEFY_SHIFT));
+ }
+}
+
+static const struct vsp1_entity_operations bru_entity_ops = {
+ .configure = bru_configure,
+};
+