[PATCH v5 3/5] media: hantro: Add RK3588 VEPU121 support

[Sebastian Reichel]

Avoid exposing each of the 4 Hantro H1 cores separately to userspace.
For now just expose the first one.

Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
 .../media/platform/verisilicon/hantro_drv.c   | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/drivers/media/platform/verisilicon/hantro_drv.c b/drivers/media/platform/verisilicon/hantro_drv.c
index 34b123dafd89..b722a20c5fe3 100644
--- a/drivers/media/platform/verisilicon/hantro_drv.c
+++ b/drivers/media/platform/verisilicon/hantro_drv.c
@@ -722,6 +722,7 @@ static const struct of_device_id of_hantro_match[] = {
 	{ .compatible = "rockchip,rk3399-vpu", .data = &rk3399_vpu_variant, },
 	{ .compatible = "rockchip,rk3568-vepu", .data = &rk3568_vepu_variant, },
 	{ .compatible = "rockchip,rk3568-vpu", .data = &rk3568_vpu_variant, },
+	{ .compatible = "rockchip,rk3588-vepu121", .data = &rk3568_vpu_variant, },
 	{ .compatible = "rockchip,rk3588-av1-vpu", .data = &rk3588_vpu981_variant, },
 #endif
 #ifdef CONFIG_VIDEO_HANTRO_IMX8M
@@ -992,6 +993,39 @@ static const struct media_device_ops hantro_m2m_media_ops = {
 	.req_queue = v4l2_m2m_request_queue,
 };
 
+/*
+ * Some SoCs, like RK3588 have multiple identical Hantro cores, but the
+ * kernel is currently missing support for multi-core handling. Exposing
+ * separate devices for each core to userspace is bad, since that does
+ * not allow scheduling tasks properly (and creates ABI). With this workaround
+ * the driver will only probe for the first core and early exit for the other
+ * cores. Once the driver gains multi-core support, the same technique
+ * for detecting the main core can be used to cluster all cores together.
+ */
+static int hantro_disable_multicore(struct hantro_dev *vpu)
+{
+	const char *compatible;
+	struct device_node *node;
+	int ret;
+
+	/* Intentionally ignores the fallback strings */
+	ret = of_property_read_string(vpu->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 (vpu->dev->of_node != node) {
+		dev_info(vpu->dev, "missing multi-core support, ignoring this instance\n");
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
 static int hantro_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *match;
@@ -1011,6 +1045,10 @@ static int hantro_probe(struct platform_device *pdev)
 	match = of_match_node(of_hantro_match, pdev->dev.of_node);
 	vpu->variant = match->data;
 
+	ret = hantro_disable_multicore(vpu);
+	if (ret)
+		return ret;
+
 	/*
 	 * Support for nxp,imx8mq-vpu is kept for backwards compatibility
 	 * but it's deprecated. Please update your DTS file to use
-- 
2.43.0