drm/v3d: Add support for V3D v4.2.

No compatible string for it yet, just the version-dependent changes.
They've now tied the hub and the core interrupt lines into a single
interrupt line coming out of the block.  It also turns out I made a
mistake in modeling the V3D v3.3 and v4.1 bridge as a part of V3D
itself -- the bridge is going away in favor of an external reset
controller in a larger HW module.

v2: Use consistent checks for whether we're on 4.2, and fix a leak in
    an error path.
v3: Use more general means of determining if the current 4.2 changes
    are in place, as apparently other platforms may switch back (noted
    by Dave).  Update the binding doc.
v4: Improve error handling for IRQ init.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190308174336.7866-2-eric@anholt.net
Reviewed-by: Dave Emett <david.emett@broadcom.com>

1 files changed, 33 insertions, 12 deletions

diff --git a/drivers/gpu/drm/v3d/v3d_irq.c b/drivers/gpu/drm/v3d/v3d_irq.c
index 29d746cfce57..b8aea2dfbe82 100644
--- a/drivers/gpu/drm/v3d/v3d_irq.c
+++ b/drivers/gpu/drm/v3d/v3d_irq.c
@@ -27,6 +27,9 @@
 			    V3D_HUB_INT_MMU_CAP |	\
 			    V3D_HUB_INT_TFUC))
 
+static irqreturn_t
+v3d_hub_irq(int irq, void *arg);
+
 static void
 v3d_overflow_mem_work(struct work_struct *work)
 {
@@ -112,6 +115,12 @@ v3d_irq(int irq, void *arg)
 	if (intsts & V3D_INT_GMPV)
 		dev_err(v3d->dev, "GMP violation\n");
 
+	/* V3D 4.2 wires the hub and core IRQs together, so if we &
+	 * didn't see the common one then check hub for MMU IRQs.
+	 */
+	if (v3d->single_irq_line && status == IRQ_NONE)
+		return v3d_hub_irq(irq, arg);
+
 	return status;
 }
 
@@ -159,7 +168,7 @@ v3d_hub_irq(int irq, void *arg)
 int
 v3d_irq_init(struct v3d_dev *v3d)
 {
-	int ret, core;
+	int irq1, ret, core;
 
 	INIT_WORK(&v3d->overflow_mem_work, v3d_overflow_mem_work);
 
@@ -170,17 +179,29 @@ v3d_irq_init(struct v3d_dev *v3d)
 		V3D_CORE_WRITE(core, V3D_CTL_INT_CLR, V3D_CORE_IRQS);
 	V3D_WRITE(V3D_HUB_INT_CLR, V3D_HUB_IRQS);
 
-	ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 0),
-			       v3d_hub_irq, IRQF_SHARED,
-			       "v3d_hub", v3d);
-	if (ret)
-		goto fail;
-
-	ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 1),
-			       v3d_irq, IRQF_SHARED,
-			       "v3d_core0", v3d);
-	if (ret)
-		goto fail;
+	irq1 = platform_get_irq(v3d->pdev, 1);
+	if (irq1 == -EPROBE_DEFER)
+		return irq1;
+	if (irq1 > 0) {
+		ret = devm_request_irq(v3d->dev, irq1,
+				       v3d_irq, IRQF_SHARED,
+				       "v3d_core0", v3d);
+		if (ret)
+			goto fail;
+		ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 0),
+				       v3d_hub_irq, IRQF_SHARED,
+				       "v3d_hub", v3d);
+		if (ret)
+			goto fail;
+	} else {
+		v3d->single_irq_line = true;
+
+		ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 0),
+				       v3d_irq, IRQF_SHARED,
+				       "v3d", v3d);
+		if (ret)
+			goto fail;
+	}
 
 	v3d_irq_enable(v3d);
 	return 0;