media: platform: amd: Introduce amd isp4 capture driver

AMD isp4 capture is a v4l2 media device which implements media controller
interface. It has one sub-device (AMD ISP4 sub-device) endpoint which can
be connected to a remote CSI2 TX endpoint. It supports only one physical
interface for now. Also add ISP4 driver related entry info into the
MAINTAINERS file

Co-developed-by: Sultan Alsawaf <sultan@kerneltoast.com>
Signed-off-by: Sultan Alsawaf <sultan@kerneltoast.com>
Co-developed-by: Svetoslav Stoilov <Svetoslav.Stoilov@amd.com>
Signed-off-by: Svetoslav Stoilov <Svetoslav.Stoilov@amd.com>
Signed-off-by: Bin Du <Bin.Du@amd.com>
Reviewed-by: Mario Limonciello (AMD) <superm1@kernel.org>
Reviewed-by: Sultan Alsawaf <sultan@kerneltoast.com>
Tested-by: Alexey Zagorodnikov <xglooom@gmail.com>
Tested-by: Kate Hsuan <hpa@redhat.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

MAINTAINERS

@@ -1152,6 +1152,19 @@ T:	git git://git.kernel.org/pub/scm/linux/kernel/git/iommu/linux.git
 F:	drivers/iommu/amd/
 F:	include/linux/amd-iommu.h
 
+AMD ISP4 DRIVER
+M:	Bin Du <bin.du@amd.com>
+M:	Nirujogi Pratap <pratap.nirujogi@amd.com>
+L:	linux-media@vger.kernel.org
+S:	Maintained
+T:	git git://linuxtv.org/media.git
+F:	drivers/media/platform/amd/Kconfig
+F:	drivers/media/platform/amd/Makefile
+F:	drivers/media/platform/amd/isp4/Kconfig
+F:	drivers/media/platform/amd/isp4/Makefile
+F:	drivers/media/platform/amd/isp4/isp4.c
+F:	drivers/media/platform/amd/isp4/isp4.h
+
 AMD KFD
 M:	Felix Kuehling <Felix.Kuehling@amd.com>
 L:	amd-gfx@lists.freedesktop.org

drivers/media/platform/Kconfig

@@ -63,6 +63,7 @@ config VIDEO_MUX
 
 # Platform drivers - Please keep it alphabetically sorted
 source "drivers/media/platform/allegro-dvt/Kconfig"
+source "drivers/media/platform/amd/Kconfig"
 source "drivers/media/platform/amlogic/Kconfig"
 source "drivers/media/platform/amphion/Kconfig"
 source "drivers/media/platform/arm/Kconfig"

drivers/media/platform/Makefile

@@ -6,6 +6,7 @@
 # Place here, alphabetically sorted by directory
 # (e. g. LC_ALL=C sort Makefile)
 obj-y += allegro-dvt/
+obj-y += amd/
 obj-y += amlogic/
 obj-y += amphion/
 obj-y += arm/

drivers/media/platform/amd/Kconfig

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+source "drivers/media/platform/amd/isp4/Kconfig"

drivers/media/platform/amd/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-y += isp4/

drivers/media/platform/amd/isp4/Kconfig

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+config VIDEO_AMD_ISP4_CAPTURE
+	tristate "AMD ISP4 and camera driver"
+	depends on DRM_AMD_ISP && VIDEO_DEV && HAS_DMA
+	select VIDEOBUF2_CORE
+	select VIDEOBUF2_MEMOPS
+	select VIDEOBUF2_V4L2
+	select VIDEOBUF2_VMALLOC
+	select VIDEO_V4L2_SUBDEV_API
+	help
+	  This is support for AMD ISP4 and camera subsystem driver.
+	  Say Y here to enable the ISP4 and camera device for video capture.
+	  To compile this driver as a module, choose M here. The module will
+	  be called amd_isp4_capture.

drivers/media/platform/amd/isp4/Makefile

@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# Copyright (C) 2025 Advanced Micro Devices, Inc.
+
+obj-$(CONFIG_VIDEO_AMD_ISP4_CAPTURE) += amd_isp4_capture.o
+amd_isp4_capture-objs := isp4.o

drivers/media/platform/amd/isp4/isp4.c

@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2025 Advanced Micro Devices, Inc.
+ */
+
+#include <linux/pm_runtime.h>
+#include <linux/vmalloc.h>
+#include <media/v4l2-ioctl.h>
+
+#include "isp4.h"
+
+#define ISP4_DRV_NAME "amd_isp_capture"
+
+static const struct {
+	const char *name;
+	u32 status_mask;
+	u32 en_mask;
+	u32 ack_mask;
+	u32 rb_int_num;
+} isp4_irq[] = {
+	/* The IRQ order is aligned with the isp4_subdev.fw_resp_thread order */
+	{
+		.name = "isp_irq_global",
+		.rb_int_num = 4, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT12 */
+	},
+	{
+		.name = "isp_irq_stream1",
+		.rb_int_num = 0, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT9 */
+	},
+};
+
+static irqreturn_t isp4_irq_handler(int irq, void *arg)
+{
+	return IRQ_HANDLED;
+}
+
+static int isp4_capture_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int irq[ARRAY_SIZE(isp4_irq)];
+	struct isp4_device *isp_dev;
+	int ret;
+
+	isp_dev = devm_kzalloc(dev, sizeof(*isp_dev), GFP_KERNEL);
+	if (!isp_dev)
+		return -ENOMEM;
+
+	dev->init_name = ISP4_DRV_NAME;
+
+	for (size_t i = 0; i < ARRAY_SIZE(isp4_irq); i++) {
+		irq[i] = platform_get_irq(pdev, isp4_irq[i].rb_int_num);
+		if (irq[i] < 0)
+			return dev_err_probe(dev, irq[i],
+					     "fail to get irq %d\n",
+					     isp4_irq[i].rb_int_num);
+
+		ret = devm_request_irq(dev, irq[i], isp4_irq_handler,
+				       IRQF_NO_AUTOEN, isp4_irq[i].name, dev);
+		if (ret)
+			return dev_err_probe(dev, ret, "fail to req irq %d\n",
+					     irq[i]);
+	}
+
+	isp_dev->v4l2_dev.mdev = &isp_dev->mdev;
+
+	strscpy(isp_dev->mdev.model, "amd_isp41_mdev",
+		sizeof(isp_dev->mdev.model));
+	isp_dev->mdev.dev = dev;
+	media_device_init(&isp_dev->mdev);
+
+	snprintf(isp_dev->v4l2_dev.name, sizeof(isp_dev->v4l2_dev.name),
+		 "AMD-V4L2-ROOT");
+	ret = v4l2_device_register(dev, &isp_dev->v4l2_dev);
+	if (ret) {
+		dev_err_probe(dev, ret, "fail register v4l2 device\n");
+		goto err_clean_media;
+	}
+
+	pm_runtime_set_suspended(dev);
+	pm_runtime_enable(dev);
+	ret = media_device_register(&isp_dev->mdev);
+	if (ret) {
+		dev_err_probe(dev, ret, "fail to register media device\n");
+		goto err_isp4_deinit;
+	}
+
+	platform_set_drvdata(pdev, isp_dev);
+
+	return 0;
+
+err_isp4_deinit:
+	pm_runtime_disable(dev);
+	v4l2_device_unregister(&isp_dev->v4l2_dev);
+err_clean_media:
+	media_device_cleanup(&isp_dev->mdev);
+
+	return ret;
+}
+
+static void isp4_capture_remove(struct platform_device *pdev)
+{
+	struct isp4_device *isp_dev = platform_get_drvdata(pdev);
+	struct device *dev = &pdev->dev;
+
+	media_device_unregister(&isp_dev->mdev);
+	pm_runtime_disable(dev);
+	v4l2_device_unregister(&isp_dev->v4l2_dev);
+	media_device_cleanup(&isp_dev->mdev);
+}
+
+static struct platform_driver isp4_capture_drv = {
+	.probe = isp4_capture_probe,
+	.remove = isp4_capture_remove,
+	.driver = {
+		.name = ISP4_DRV_NAME,
+	}
+};
+
+module_platform_driver(isp4_capture_drv);
+
+MODULE_ALIAS("platform:" ISP4_DRV_NAME);
+MODULE_IMPORT_NS("DMA_BUF");
+
+MODULE_DESCRIPTION("AMD ISP4 Driver");
+MODULE_AUTHOR("Bin Du <bin.du@amd.com>");
+MODULE_AUTHOR("Pratap Nirujogi <pratap.nirujogi@amd.com>");
+MODULE_LICENSE("GPL");

drivers/media/platform/amd/isp4/isp4.h

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2025 Advanced Micro Devices, Inc.
+ */
+
+#ifndef _ISP4_H_
+#define _ISP4_H_
+
+#include <media/v4l2-device.h>
+#include <media/videobuf2-memops.h>
+
+struct isp4_device {
+	struct v4l2_device v4l2_dev;
+	struct media_device mdev;
+};
+
+#endif /* _ISP4_H_ */