Merge tag 'drm/tegra/for-5.19-prep-work' of https://gitlab.freedesktop.org/drm/tegra into drm-next

drm/tegra: Preparatory work for v5.19

This contains a single patch from a series that's ready to go for v5.10
but is also a shared build-time dependency for an IOMMU series that is
planned for v5.20. The idea is to take this into v5.19 to fulfill that
dependency and remove the need for close coordination for the two
series.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220601100335.3841301-1-thierry.reding@gmail.com

5 files changed, 53 insertions, 2 deletions

diff --git a/drivers/gpu/Makefile b/drivers/gpu/Makefile
index 835c88318cec..8997f0096545 100644
--- a/drivers/gpu/Makefile
+++ b/drivers/gpu/Makefile
@@ -2,7 +2,6 @@
 # drm/tegra depends on host1x, so if both drivers are built-in care must be
 # taken to initialize them in the correct order. Link order is the only way
 # to ensure this currently.
-obj-$(CONFIG_TEGRA_HOST1X)	+= host1x/
-obj-y			+= drm/ vga/
+obj-y			+= host1x/ drm/ vga/
 obj-$(CONFIG_IMX_IPUV3_CORE)	+= ipu-v3/
 obj-$(CONFIG_TRACE_GPU_MEM)		+= trace/
diff --git a/drivers/gpu/host1x/Kconfig b/drivers/gpu/host1x/Kconfig
index 6815b4db17c1..1861a8180d3f 100644
--- a/drivers/gpu/host1x/Kconfig
+++ b/drivers/gpu/host1x/Kconfig
@@ -1,8 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0-only
+
+config TEGRA_HOST1X_CONTEXT_BUS
+	bool
+
 config TEGRA_HOST1X
 	tristate "NVIDIA Tegra host1x driver"
 	depends on ARCH_TEGRA || (ARM && COMPILE_TEST)
 	select DMA_SHARED_BUFFER
+	select TEGRA_HOST1X_CONTEXT_BUS
 	select IOMMU_IOVA
 	help
 	  Driver for the NVIDIA Tegra host1x hardware.
diff --git a/drivers/gpu/host1x/Makefile b/drivers/gpu/host1x/Makefile
index d2b6f7de0498..c891a3e33844 100644
--- a/drivers/gpu/host1x/Makefile
+++ b/drivers/gpu/host1x/Makefile
@@ -18,3 +18,4 @@ host1x-y = \
 	hw/host1x07.o
 
 obj-$(CONFIG_TEGRA_HOST1X) += host1x.o
+obj-$(CONFIG_TEGRA_HOST1X_CONTEXT_BUS) += context_bus.o
diff --git a/drivers/gpu/host1x/context_bus.c b/drivers/gpu/host1x/context_bus.c
new file mode 100644
index 000000000000..b0d35b2bbe89
--- /dev/null
+++ b/drivers/gpu/host1x/context_bus.c
@@ -0,0 +1,31 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021, NVIDIA Corporation.
+ */
+
+#include <linux/device.h>
+#include <linux/of.h>
+
+struct bus_type host1x_context_device_bus_type = {
+	.name = "host1x-context",
+};
+EXPORT_SYMBOL_GPL(host1x_context_device_bus_type);
+
+static int __init host1x_context_device_bus_init(void)
+{
+	int err;
+
+	if (!of_machine_is_compatible("nvidia,tegra186") &&
+	    !of_machine_is_compatible("nvidia,tegra194") &&
+	    !of_machine_is_compatible("nvidia,tegra234"))
+		return 0;
+
+	err = bus_register(&host1x_context_device_bus_type);
+	if (err < 0) {
+		pr_err("bus type registration failed: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+postcore_initcall(host1x_context_device_bus_init);
diff --git a/include/linux/host1x_context_bus.h b/include/linux/host1x_context_bus.h
new file mode 100644
index 000000000000..72462737a6db
--- /dev/null
+++ b/include/linux/host1x_context_bus.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2021, NVIDIA Corporation. All rights reserved.
+ */
+
+#ifndef __LINUX_HOST1X_CONTEXT_BUS_H
+#define __LINUX_HOST1X_CONTEXT_BUS_H
+
+#include <linux/device.h>
+
+#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
+extern struct bus_type host1x_context_device_bus_type;
+#endif
+
+#endif