drm: rcar-du: Split CRTC handling to support hardware indexing

The DU CRTC driver does not support distinguishing between a hardware
index, and a software (CRTC) index in the event that a DU channel might
not be populated by the hardware.

Support this by adapting the rcar_du_device_info structure to store a
bitmask of available channels rather than a count of CRTCs. The count
can then be obtained by determining the hamming weight of the bitmask.

This allows the rcar_du_crtc_create() function to distinguish between
both index types, and non-populated DU channels will be skipped without
leaving a gap in the software CRTC indexes.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

1 files changed, 14 insertions, 12 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index c4420538ec85..f2a0bd1e5119 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -767,7 +767,8 @@ static irqreturn_t rcar_du_crtc_irq(int irq, void *arg)
  * Initialization
  */
 
-int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
+int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int swindex,
+			unsigned int hwindex)
 {
 	static const unsigned int mmio_offsets[] = {
 		DU0_REG_OFFSET, DU1_REG_OFFSET, DU2_REG_OFFSET, DU3_REG_OFFSET
@@ -775,7 +776,7 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 
 	struct rcar_du_device *rcdu = rgrp->dev;
 	struct platform_device *pdev = to_platform_device(rcdu->dev);
-	struct rcar_du_crtc *rcrtc = &rcdu->crtcs[index];
+	struct rcar_du_crtc *rcrtc = &rcdu->crtcs[swindex];
 	struct drm_crtc *crtc = &rcrtc->crtc;
 	struct drm_plane *primary;
 	unsigned int irqflags;
@@ -787,7 +788,7 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 
 	/* Get the CRTC clock and the optional external clock. */
 	if (rcar_du_has(rcdu, RCAR_DU_FEATURE_CRTC_IRQ_CLOCK)) {
-		sprintf(clk_name, "du.%u", index);
+		sprintf(clk_name, "du.%u", hwindex);
 		name = clk_name;
 	} else {
 		name = NULL;
@@ -795,16 +796,16 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 
 	rcrtc->clock = devm_clk_get(rcdu->dev, name);
 	if (IS_ERR(rcrtc->clock)) {
-		dev_err(rcdu->dev, "no clock for CRTC %u\n", index);
+		dev_err(rcdu->dev, "no clock for DU channel %u\n", hwindex);
 		return PTR_ERR(rcrtc->clock);
 	}
 
-	sprintf(clk_name, "dclkin.%u", index);
+	sprintf(clk_name, "dclkin.%u", hwindex);
 	clk = devm_clk_get(rcdu->dev, clk_name);
 	if (!IS_ERR(clk)) {
 		rcrtc->extclock = clk;
 	} else if (PTR_ERR(rcrtc->clock) == -EPROBE_DEFER) {
-		dev_info(rcdu->dev, "can't get external clock %u\n", index);
+		dev_info(rcdu->dev, "can't get external clock %u\n", hwindex);
 		return -EPROBE_DEFER;
 	}
 
@@ -813,13 +814,13 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 	spin_lock_init(&rcrtc->vblank_lock);
 
 	rcrtc->group = rgrp;
-	rcrtc->mmio_offset = mmio_offsets[index];
-	rcrtc->index = index;
+	rcrtc->mmio_offset = mmio_offsets[hwindex];
+	rcrtc->index = hwindex;
 
 	if (rcar_du_has(rcdu, RCAR_DU_FEATURE_VSP1_SOURCE))
 		primary = &rcrtc->vsp->planes[rcrtc->vsp_pipe].plane;
 	else
-		primary = &rgrp->planes[index % 2].plane;
+		primary = &rgrp->planes[swindex % 2].plane;
 
 	ret = drm_crtc_init_with_planes(rcdu->ddev, crtc, primary,
 					NULL, &crtc_funcs, NULL);
@@ -833,7 +834,8 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 
 	/* Register the interrupt handler. */
 	if (rcar_du_has(rcdu, RCAR_DU_FEATURE_CRTC_IRQ_CLOCK)) {
-		irq = platform_get_irq(pdev, index);
+		/* The IRQ's are associated with the CRTC (sw)index. */
+		irq = platform_get_irq(pdev, swindex);
 		irqflags = 0;
 	} else {
 		irq = platform_get_irq(pdev, 0);
@@ -841,7 +843,7 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 	}
 
 	if (irq < 0) {
-		dev_err(rcdu->dev, "no IRQ for CRTC %u\n", index);
+		dev_err(rcdu->dev, "no IRQ for CRTC %u\n", swindex);
 		return irq;
 	}
 
@@ -849,7 +851,7 @@ int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 			       dev_name(rcdu->dev), rcrtc);
 	if (ret < 0) {
 		dev_err(rcdu->dev,
-			"failed to register IRQ for CRTC %u\n", index);
+			"failed to register IRQ for CRTC %u\n", swindex);
 		return ret;
 	}