[PATCH v2 20/22] media: rockchip: rga: disable multi-core support

[Sven Püschel]

Disable multi-core support in preparation of the RGA3 addition. The
RK3588 SoC features two equal RGA3 cores. This allows scheduling of the
work between both cores, which is not yet implemented. Until it is
implemented avoid exposing both cores as independent video devices to
prevent an ABI breakage when multi-core support is added.

Signed-off-by: Sven Püschel <s.pueschel at pengutronix.de>
---
 drivers/media/platform/rockchip/rga/rga.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
index 3958e71b8987d..65686228b7300 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -660,6 +660,30 @@ static int rga_parse_dt(struct rockchip_rga *rga)
 	return 0;
 }
 
+static int rga_disable_multicore(struct device *dev)
+{
+	const char *compatible;
+	struct device_node *node;
+	int ret;
+
+	/* Intentionally ignores the fallback strings */
+	ret = of_property_read_string(dev->of_node, "compatible", &compatible);
+	if (ret)
+		return ret;
+
+	/* first compatible node found from the root node is considered the main core */
+	node = of_find_compatible_node(NULL, NULL, compatible);
+	if (!node)
+		return -EINVAL; /* broken DT? */
+
+	if (dev->of_node != node) {
+		dev_info(dev, "missing multi-core support, ignoring this instance\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 static int rga_probe(struct platform_device *pdev)
 {
 	struct rockchip_rga *rga;
@@ -670,6 +694,10 @@ static int rga_probe(struct platform_device *pdev)
 	if (!pdev->dev.of_node)
 		return -ENODEV;
 
+	ret = rga_disable_multicore(&pdev->dev);
+	if (ret)
+		return ret;
+
 	rga = devm_kzalloc(&pdev->dev, sizeof(*rga), GFP_KERNEL);
 	if (!rga)
 		return -ENOMEM;

-- 
2.52.0