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

[Rob Herring]

On Mon, Apr 09, 2018 at 04:00:38PM -0700, 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.
> 
> Signed-off-by: Eric Anholt 
> ---
>  .../bindings/display/brcm,bcm-vc4.txt |  7 
>  drivers/gpu/drm/vc4/vc4_drv.c | 33 ++-
>  drivers/gpu/drm/vc4/vc4_hvs.c |  1 +
>  drivers/gpu/drm/vc4/vc4_v3d.c |  1 +
>  4 files changed, 27 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..d282ab7de03a 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -364,22 +364,34 @@ 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)
> +{
> + int i;
> +

> + for (i = 0; driver->driver.of_match_table[i].compatible; i++) {
> + const char *compat = 
> driver->driver.of_match_table[i].compatible;
> + struct device_node *node;
> +
> + while ((node = of_find_compatible_node(node, NULL, compat))) {
> + if (of_device_is_available(node)) {
> + of_node_put(node);
> + return true;
> + }
> + }
> + }

All this can be replaced with:

node = of_find_matching_node_and_match(NULL, driver->driver.of_match_table, 
NULL);
if (of_device_is_available(node)) {
of_node_put(node);
return true;
}

> +
> + return false;
> +}
> +

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

[Rob Herring]

On Mon, Apr 09, 2018 at 04:00:38PM -0700, 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.
> 
> Signed-off-by: Eric Anholt 
> ---
>  .../bindings/display/brcm,bcm-vc4.txt |  7 
>  drivers/gpu/drm/vc4/vc4_drv.c | 33 ++-
>  drivers/gpu/drm/vc4/vc4_hvs.c |  1 +
>  drivers/gpu/drm/vc4/vc4_v3d.c |  1 +
>  4 files changed, 27 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..d282ab7de03a 100644
> --- a/drivers/gpu/drm/vc4/vc4_drv.c
> +++ b/drivers/gpu/drm/vc4/vc4_drv.c
> @@ -364,22 +364,34 @@ 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)
> +{
> + int i;
> +

> + for (i = 0; driver->driver.of_match_table[i].compatible; i++) {
> + const char *compat = 
> driver->driver.of_match_table[i].compatible;
> + struct device_node *node;
> +
> + while ((node = of_find_compatible_node(node, NULL, compat))) {
> + if (of_device_is_available(node)) {
> + of_node_put(node);
> + return true;
> + }
> + }
> + }

All this can be replaced with:

node = of_find_matching_node_and_match(NULL, driver->driver.of_match_table, 
NULL);
if (of_device_is_available(node)) {
of_node_put(node);
return true;
}

> +
> + return false;
> +}
> +

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

[Eric Anholt]

Stefan Wahren  writes:

> Hi Eric,
>
>> Eric Anholt  hat am 10. April 2018 um 01:00 geschrieben:
>> 
>> 
>> 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.
>
> i didn't test it. Does the code change keep the backward compatibility with 
> older DT?

Yes.


signature.asc
Description: PGP signature

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

[Eric Anholt]

Stefan Wahren  writes:

> Hi Eric,
>
>> Eric Anholt  hat am 10. April 2018 um 01:00 geschrieben:
>> 
>> 
>> 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.
>
> i didn't test it. Does the code change keep the backward compatibility with 
> older DT?

Yes.


signature.asc
Description: PGP signature

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

[Stefan Wahren]

Hi Eric,

> Eric Anholt  hat am 10. April 2018 um 01:00 geschrieben:
> 
> 
> 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.

i didn't test it. Does the code change keep the backward compatibility with 
older DT?

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

[Stefan Wahren]

Hi Eric,

> Eric Anholt  hat am 10. April 2018 um 01:00 geschrieben:
> 
> 
> 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.

i didn't test it. Does the code change keep the backward compatibility with 
older DT?