[PATCH v3 1/3] drm/v3d: Add support for V3D v4.2.

Eric Anholt
2019-02-20T23:37:07Z

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.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
.../devicetree/bindings/gpu/brcm,bcm-v3d.txt | 11 ++++++--
drivers/gpu/drm/v3d/v3d_drv.c | 21 +++++++++++---
drivers/gpu/drm/v3d/v3d_drv.h | 2 ++
drivers/gpu/drm/v3d/v3d_gem.c | 12 +++++++-
drivers/gpu/drm/v3d/v3d_irq.c | 28 +++++++++++++++----
5 files changed, 60 insertions(+), 14 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt b/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt
index c907aa8dd755..b2df82b44625 100644
--- a/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt
+++ b/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt
@@ -6,15 +6,20 @@ For V3D 2.x, see brcm,bcm-vc4.txt.
Required properties:
- compatible: Should be "brcm,7268-v3d" or "brcm,7278-v3d"
- reg: Physical base addresses and lengths of the register areas
-- reg-names: Names for the register areas. The "hub", "bridge", and "core0"
+- reg-names: Names for the register areas. The "hub" and "core0"
register areas are always required. The "gca" register area
- is required if the GCA cache controller is present.
+ is required if the GCA cache controller is present. The
+ "bridge" register area is required if an external reset
+ controller is not present.
- interrupts: The interrupt numbers. The first interrupt is for the hub,
- while the following interrupts are for the cores.
+ while the following interrupts are separate interrupt lines
+ for the cores (if they don't share the hub's interrupt).
See bindings/interrupt-controller/interrupts.txt

Optional properties:
- clocks: The core clock the unit runs on
+- resets: The reset line for v3d, if not using a mapping of the bridge
+ See bindings/reset/reset.txt

v3d {
compatible = "brcm,7268-v3d";
diff --git a/drivers/gpu/drm/v3d/v3d_drv.c b/drivers/gpu/drm/v3d/v3d_drv.c
index b189b1a0ae7e..392e458b55bd 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.c
+++ b/drivers/gpu/drm/v3d/v3d_drv.c
@@ -19,6 +19,7 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <drm/drm_fb_cma_helper.h>
#include <drm/drm_gem_framebuffer_helper.h>
#include <drm/drm_fb_helper.h>
@@ -496,10 +497,6 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
v3d->pdev = pdev;
drm = &v3d->drm;

- ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
- if (ret)
- goto dev_free;
-
ret = map_regs(v3d, &v3d->hub_regs, "hub");
if (ret)
goto dev_free;
@@ -514,6 +511,22 @@ static int v3d_platform_drm_probe(struct platform_device *pdev)
v3d->cores = V3D_GET_FIELD(ident1, V3D_HUB_IDENT1_NCORES);
WARN_ON(v3d->cores > 1); /* multicore not yet implemented */

+ v3d->reset = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(v3d->reset)) {
+ ret = PTR_ERR(v3d->reset);
+
+ if (ret == -EPROBE_DEFER)
+ goto dev_free;
+
+ v3d->reset = NULL;
+ ret = map_regs(v3d, &v3d->bridge_regs, "bridge");
+ if (ret) {
+ dev_err(dev,
+ "Failed to get reset control or bridge regs\n");
+ goto dev_free;
+ }
+ }
+
if (v3d->ver < 41) {
ret = map_regs(v3d, &v3d->gca_regs, "gca");
if (ret)
diff --git a/drivers/gpu/drm/v3d/v3d_drv.h b/drivers/gpu/drm/v3d/v3d_drv.h
index 9e0e11f57307..fab9979b7e1f 100644
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -39,6 +39,7 @@ struct v3d_dev {
* and revision.
*/
int ver;
+ bool single_irq_line;

struct device *dev;
struct platform_device *pdev;
@@ -47,6 +48,7 @@ struct v3d_dev {
void __iomem *bridge_regs;
void __iomem *gca_regs;
struct clk *clk;
+ struct reset_control *reset;

/* Virtual and DMA addresses of the single shared page table. */
volatile u32 *pt;
diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index 0d1e5e0b8042..109be31e47ea 100644
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -6,6 +6,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
#include <linux/device.h>
#include <linux/io.h>
#include <linux/sched/signal.h>
@@ -69,7 +70,7 @@ v3d_idle_gca(struct v3d_dev *v3d)
}

static void
-v3d_reset_v3d(struct v3d_dev *v3d)
+v3d_reset_by_bridge(struct v3d_dev *v3d)
{
int version = V3D_BRIDGE_READ(V3D_TOP_GR_BRIDGE_REVISION);

@@ -89,6 +90,15 @@ v3d_reset_v3d(struct v3d_dev *v3d)
V3D_TOP_GR_BRIDGE_SW_INIT_1_V3D_CLK_108_SW_INIT);
V3D_BRIDGE_WRITE(V3D_TOP_GR_BRIDGE_SW_INIT_1, 0);
}
+}
+
+static void
+v3d_reset_v3d(struct v3d_dev *v3d)
+{
+ if (v3d->reset)
+ reset_control_reset(v3d->reset);
+ else
+ v3d_reset_by_bridge(v3d);

v3d_init_hw_state(v3d);
}
diff --git a/drivers/gpu/drm/v3d/v3d_irq.c b/drivers/gpu/drm/v3d/v3d_irq.c
index 69338da70ddc..288ab1036a7a 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;
}

@@ -170,12 +179,19 @@ 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);
- ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 1),
- v3d_irq, IRQF_SHARED,
- "v3d_core0", v3d);
+ if (platform_get_irq(v3d->pdev, 1) < 0) {
+ ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 0),
+ v3d_irq, IRQF_SHARED,
+ "v3d", v3d);
+ v3d->single_irq_line = true;
+ } else {
+ ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 0),
+ v3d_hub_irq, IRQF_SHARED,
+ "v3d_hub", v3d);
+ ret = devm_request_irq(v3d->dev, platform_get_irq(v3d->pdev, 1),
+ v3d_irq, IRQF_SHARED,
+ "v3d_core0", v3d);
+ }
if (ret)
dev_err(v3d->dev, "IRQ setup failed: %d\n", ret);

--
2.20.1