[PATCH v2 1/3] drm/vc4: Remove the need for the GPU-subsystem DT node.

From: Eric Anholt
Date: Mon Apr 16 2018 - 13:25:56 EST


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.

Signed-off-by: Eric Anholt <eric@xxxxxxxxxx>
---
.../bindings/display/brcm,bcm-vc4.txt | 7 -----
drivers/gpu/drm/vc4/vc4_drv.c | 29 ++++++++++++++-----
drivers/gpu/drm/vc4/vc4_hvs.c | 1 +
drivers/gpu/drm/vc4/vc4_v3d.c | 1 +
4 files changed, 23 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@7ec00000 {
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..13b840b534b8 100644
--- a/drivers/gpu/drm/vc4/vc4_drv.c
+++ b/drivers/gpu/drm/vc4/vc4_drv.c
@@ -364,22 +364,30 @@ 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;
+
+ 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;
+}
+
static int __init vc4_drm_register(void)
{
int ret;
@@ -389,6 +397,11 @@ 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