Re: [PATCH v3 1/3] drm/vc4: Remove the need for the GPU-subsystem DT node.

2018-04-17 Thread Eric Anholt 
Rob Herring  writes:

> On Mon, Apr 16, 2018 at 5:52 PM, Eric Anholt  wrote:
>> The GPU subsystem node was a workaround to have a central device to
>> bind V3D and display to.  Following the lead of 246774d17fc0
>> ("drm/etnaviv: remove the need for a gpu-subsystem DT node"), remove
>> the subsystem node usage and just create a platform device for the DRM
>> device to attach to if any of the subsystem devices are present.
>>
>> v2: Simplify the DT walking code.
>> v3: Always put the node.
>>
>> Signed-off-by: Eric Anholt 
>> ---
>>  .../bindings/display/brcm,bcm-vc4.txt |  7 -
>>  drivers/gpu/drm/vc4/vc4_drv.c | 28 +--
>>  drivers/gpu/drm/vc4/vc4_hvs.c |  1 +
>>  drivers/gpu/drm/vc4/vc4_v3d.c |  1 +
>>  4 files changed, 22 insertions(+), 15 deletions(-)
>
> Reviewed-by: Rob Herring 

Unfortunately, on further testing, this ends up broken.  My guess is
that our new platform device isn't on the same bus, so we don't get our
dma-ranges translation when we use drm->dev, and that breaks caching
behavior.


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Re: [PATCH v3 1/3] drm/vc4: Remove the need for the GPU-subsystem DT node.

2018-04-17 Thread Rob Herring 
On Mon, Apr 16, 2018 at 5:52 PM, Eric Anholt  wrote:
> The GPU subsystem node was a workaround to have a central device to
> bind V3D and display to.  Following the lead of 246774d17fc0
> ("drm/etnaviv: remove the need for a gpu-subsystem DT node"), remove
> the subsystem node usage and just create a platform device for the DRM
> device to attach to if any of the subsystem devices are present.
>
> v2: Simplify the DT walking code.
> v3: Always put the node.
>
> Signed-off-by: Eric Anholt 
> ---
>  .../bindings/display/brcm,bcm-vc4.txt |  7 -
>  drivers/gpu/drm/vc4/vc4_drv.c | 28 +--
>  drivers/gpu/drm/vc4/vc4_hvs.c |  1 +
>  drivers/gpu/drm/vc4/vc4_v3d.c |  1 +
>  4 files changed, 22 insertions(+), 15 deletions(-)

Reviewed-by: Rob Herring

[PATCH v3 1/3] drm/vc4: Remove the need for the GPU-subsystem DT node.

2018-04-16 Thread Eric Anholt 
The GPU subsystem node was a workaround to have a central device to
bind V3D and display to.  Following the lead of 246774d17fc0
("drm/etnaviv: remove the need for a gpu-subsystem DT node"), remove
the subsystem node usage and just create a platform device for the DRM
device to attach to if any of the subsystem devices are present.

v2: Simplify the DT walking code.
v3: Always put the node.

Signed-off-by: Eric Anholt 
---
 .../bindings/display/brcm,bcm-vc4.txt |  7 -
 drivers/gpu/drm/vc4/vc4_drv.c | 28 +--
 drivers/gpu/drm/vc4/vc4_hvs.c |  1 +
 drivers/gpu/drm/vc4/vc4_v3d.c |  1 +
 4 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt 
b/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
index 284e2b14cfbe..5fd4717101d6 100644
--- a/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
+++ b/Documentation/devicetree/bindings/display/brcm,bcm-vc4.txt
@@ -4,9 +4,6 @@ The VC4 device present on the Raspberry Pi includes a display 
system
 with HDMI output and the HVS (Hardware Video Scaler) for compositing
 display planes.
 
-Required properties for VC4:
-- compatible:  Should be "brcm,bcm2835-vc4" or "brcm,cygnus-vc4"
-
 Required properties for Pixel Valve:
 - compatible:  Should be one of "brcm,bcm2835-pixelvalve0",
  "brcm,bcm2835-pixelvalve1", or "brcm,bcm2835-pixelvalve2"
@@ -153,10 +150,6 @@ v3d: v3d@7ec0 {
interrupts = <1 10>;
 };
 
-vc4: gpu {
-   compatible = "brcm,bcm2835-vc4";
-};
-
 panel: panel {
compatible = "ontat,yx700wv03", "simple-panel";
 
diff --git a/drivers/gpu/drm/vc4/vc4_drv.c b/drivers/gpu/drm/vc4/vc4_drv.c
index 7c95ed5c5cac..e8ba9e7c71d2 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -364,22 +364,29 @@ static int vc4_platform_drm_remove(struct platform_device 
*pdev)
return 0;
 }
 
-static const struct of_device_id vc4_of_match[] = {
-   { .compatible = "brcm,bcm2835-vc4", },
-   { .compatible = "brcm,cygnus-vc4", },
-   {},
-};
-MODULE_DEVICE_TABLE(of, vc4_of_match);
-
 static struct platform_driver vc4_platform_driver = {
.probe  = vc4_platform_drm_probe,
.remove = vc4_platform_drm_remove,
.driver = {
.name   = "vc4-drm",
-   .of_match_table = vc4_of_match,
},
 };
 
+static bool
+driver_of_table_has_a_match(const struct platform_driver *driver)
+{
+   struct device_node *node;
+   bool ret;
+
+   node = of_find_matching_node_and_match(NULL,
+  driver->driver.of_match_table,
+  NULL);
+   ret = of_device_is_available(node);
+   of_node_put(node);
+
+   return ret;
+}
+
 static int __init vc4_drm_register(void)
 {
int ret;
@@ -389,6 +396,11 @@ static int __init vc4_drm_register(void)
if (ret)
return ret;
 
+   if (driver_of_table_has_a_match(&vc4_v3d_driver) ||
+   driver_of_table_has_a_match(&vc4_hvs_driver)) {
+   platform_device_register_simple("vc4-drm", -1, NULL, 0);
+   }
+
return platform_driver_register(&vc4_platform_driver);
 }
 
diff --git a/drivers/gpu/drm/vc4/vc4_hvs.c b/drivers/gpu/drm/vc4/vc4_hvs.c
index 2b62fc5b8d85..730813ee74ae 100644
--- a/drivers/gpu/drm/vc4/vc4_hvs.c
+++ b/drivers/gpu/drm/vc4/vc4_hvs.c
@@ -262,6 +262,7 @@ static const struct of_device_id vc4_hvs_dt_match[] = {
{ .compatible = "brcm,bcm2835-hvs" },
{}
 };
+MODULE_DEVICE_TABLE(of, vc4_hvs_dt_match);
 
 struct platform_driver vc4_hvs_driver = {
.probe = vc4_hvs_dev_probe,
diff --git a/drivers/gpu/drm/vc4/vc4_v3d.c b/drivers/gpu/drm/vc4/vc4_v3d.c
index bfc2fa73d2ae..e77e9ebbab4b 100644
--- a/drivers/gpu/drm/vc4/vc4_v3d.c
+++ b/drivers/gpu/drm/vc4/vc4_v3d.c
@@ -459,6 +459,7 @@ static const struct of_device_id vc4_v3d_dt_match[] = {
{ .compatible = "brcm,vc4-v3d" },
{}
 };
+MODULE_DEVICE_TABLE(of, vc4_v3d_dt_match);
 
 struct platform_driver vc4_v3d_driver = {
.probe = vc4_v3d_dev_probe,
-- 
2.17.0