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>

diff --git a/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt b/Documentation/devicetree/bindings/gpu/brcm,bcm-v3d.txt
index c907aa8..b2df82b 100644 (file)
--- 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 f9906ca..89b7567 100644 (file)
--- 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_fb_helper.h>
 
@@ -264,10 +265,6 @@ 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;
@@ -282,6 +279,22 @@ 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 bb58ecb..b5efac7 100644 (file)
--- a/drivers/gpu/drm/v3d/v3d_drv.h
+++ b/drivers/gpu/drm/v3d/v3d_drv.h
@@ -33,6 +33,7 @@ struct v3d_dev {
         * and revision.
         */
        int ver;
+       bool single_irq_line;
 
        struct device *dev;
        struct platform_device *pdev;
@@ -41,6 +42,7 @@ 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 0a83268..449d01e 100644 (file)
--- 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>
@@ -70,7 +71,7 @@ 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);
 
@@ -90,6 +91,15 @@ 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 29d746c..b8aea2d 100644 (file)
--- 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;