Re: [PATCH v2 1/8] media: platform: amd: Introduce amd isp4 capture driver

Sakari Ailus
2025-07-28T05:54:51Z

Hi Bin,

On Wed, Jun 18, 2025 at 05:19:52PM +0800, Bin Du wrote:
> 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 MAINAINERS file

You could rewrap the text and use the full lines here -- up to 75
characters per line.

>
> Signed-off-by: Bin Du <Bin.Du@amd.com>
> Signed-off-by: Svetoslav Stoilov <Svetoslav.Stoilov@amd.com>
> ---
> MAINTAINERS | 10 ++
> drivers/media/platform/Kconfig | 1 +
> drivers/media/platform/Makefile | 1 +
> drivers/media/platform/amd/Kconfig | 17 +++
> drivers/media/platform/amd/Makefile | 5 +
> drivers/media/platform/amd/isp4/Makefile | 21 ++++
> drivers/media/platform/amd/isp4/isp4.c | 139 +++++++++++++++++++++++
> drivers/media/platform/amd/isp4/isp4.h | 35 ++++++
> 8 files changed, 229 insertions(+)
> create mode 100644 drivers/media/platform/amd/Kconfig
> create mode 100644 drivers/media/platform/amd/Makefile
> create mode 100644 drivers/media/platform/amd/isp4/Makefile
> create mode 100644 drivers/media/platform/amd/isp4/isp4.c
> create mode 100644 drivers/media/platform/amd/isp4/isp4.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 10893c91b1c1..15070afb14b5 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1107,6 +1107,16 @@ 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/*
> +
> AMD KFD
> M: Felix Kuehling <Felix.Kuehling@amd.com>
> L: amd-gfx@lists.freedesktop.org
> diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
> index 85d2627776b6..d525c2262a7d 100644
> --- a/drivers/media/platform/Kconfig
> +++ b/drivers/media/platform/Kconfig
> @@ -89,5 +89,6 @@ source "drivers/media/platform/ti/Kconfig"
> source "drivers/media/platform/verisilicon/Kconfig"
> source "drivers/media/platform/via/Kconfig"
> source "drivers/media/platform/xilinx/Kconfig"
> +source "drivers/media/platform/amd/Kconfig"
>
> endif # MEDIA_PLATFORM_DRIVERS
> diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
> index ace4e34483dd..9f3d1693868d 100644
> --- a/drivers/media/platform/Makefile
> +++ b/drivers/media/platform/Makefile
> @@ -32,6 +32,7 @@ obj-y += ti/
> obj-y += verisilicon/
> obj-y += via/
> obj-y += xilinx/
> +obj-y += amd/
>
> # Please place here only ancillary drivers that aren't SoC-specific
> # Please keep it alphabetically sorted by Kconfig name
> diff --git a/drivers/media/platform/amd/Kconfig b/drivers/media/platform/amd/Kconfig
> new file mode 100644
> index 000000000000..3b1dba0400a0
> --- /dev/null
> +++ b/drivers/media/platform/amd/Kconfig
> @@ -0,0 +1,17 @@
> +# SPDX-License-Identifier: MIT
> +
> +config AMD_ISP4
> + tristate "AMD ISP4 and camera driver"
> + default y
> + depends on VIDEO_DEV && VIDEO_V4L2_SUBDEV_API
> + select VIDEOBUF2_CORE
> + select VIDEOBUF2_V4L2
> + select VIDEOBUF2_MEMOPS
> + select VIDEOBUF2_VMALLOC
> + select VIDEOBUF2_DMA_CONTIG
> + select VIDEOBUF2_DMA_SG

Do you need all these three? Most drivers need only one.

> + 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_capture.
> diff --git a/drivers/media/platform/amd/Makefile b/drivers/media/platform/amd/Makefile
> new file mode 100644
> index 000000000000..76146efcd2bf
> --- /dev/null
> +++ b/drivers/media/platform/amd/Makefile
> @@ -0,0 +1,5 @@
> +# Copyright 2024 Advanced Micro Devices, Inc.
> +# add isp block
> +ifneq ($(CONFIG_AMD_ISP4),)
> +obj-y += isp4/
> +endif
> diff --git a/drivers/media/platform/amd/isp4/Makefile b/drivers/media/platform/amd/isp4/Makefile
> new file mode 100644
> index 000000000000..e9e84160517d
> --- /dev/null
> +++ b/drivers/media/platform/amd/isp4/Makefile
> @@ -0,0 +1,21 @@
> +# SPDX-License-Identifier: GPL-2.0+
> +#
> +# Copyright (C) 2025 Advanced Micro Devices, Inc.
> +
> +obj-$(CONFIG_AMD_ISP4) += amd_capture.o
> +amd_capture-objs := isp4.o
> +
> +ccflags-y += -I$(srctree)/drivers/media/platform/amd/isp4
> +ccflags-y += -I$(srctree)/include
> +
> +ifneq ($(call cc-option, -mpreferred-stack-boundary=4),)
> + cc_stack_align := -mpreferred-stack-boundary=4
> +endif

Uh... does the driver actually depend on this?

> +
> +ccflags-y += $(cc_stack_align)
> +ccflags-y += -DCONFIG_COMPAT
> +ccflags-y += -Wunused-but-set-variable
> +ccflags-y += -Wmissing-include-dirs
> +ccflags-y += -Wunused-const-variable
> +ccflags-y += -Wmaybe-uninitialized
> +ccflags-y += -Wunused-value
> diff --git a/drivers/media/platform/amd/isp4/isp4.c b/drivers/media/platform/amd/isp4/isp4.c
> new file mode 100644
> index 000000000000..d0be90c5ec3b
> --- /dev/null
> +++ b/drivers/media/platform/amd/isp4/isp4.c
> @@ -0,0 +1,139 @@
> +// 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>

Alphabetic order, please.

> +
> +#include "isp4.h"
> +
> +#define VIDEO_BUF_NUM 5

Unused.

> +
> +#define ISP4_DRV_NAME "amd_isp_capture"
> +
> +/* interrupt num */
> +static const u32 isp4_ringbuf_interrupt_num[] = {
> + 0, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT9 */
> + 1, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT10 */
> + 3, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT11 */
> + 4, /* ISP_4_1__SRCID__ISP_RINGBUFFER_WPT12 */
> +};
> +
> +#define to_isp4_device(dev) \
> + ((struct isp4_device *)container_of(dev, struct isp4_device, v4l2_dev))

No need for the cast.

> +
> +static irqreturn_t isp4_irq_handler(int irq, void *arg)
> +{
> + struct isp4_device *isp_dev = dev_get_drvdata((struct device *)arg);
> +
> + if (!isp_dev)
> + goto error_drv_data;
> +
> +error_drv_data:
> + return IRQ_HANDLED;
> +}
> +
> +/*
> + * amd capture module
> + */
> +static int isp4_capture_probe(struct platform_device *pdev)
> +{
> + struct device *dev = &pdev->dev;
> + struct isp4_device *isp_dev;
> +

Extra newline.

> + int i, irq, ret;

unsigned int i?

> +
> + isp_dev = devm_kzalloc(&pdev->dev, sizeof(*isp_dev), GFP_KERNEL);
> + if (!isp_dev)
> + return -ENOMEM;
> +
> + isp_dev->pdev = pdev;
> + dev->init_name = ISP4_DRV_NAME;
> +
> + for (i = 0; i < ARRAY_SIZE(isp4_ringbuf_interrupt_num); i++) {
> + irq = platform_get_irq(pdev, isp4_ringbuf_interrupt_num[i]);
> + if (irq < 0)
> + return dev_err_probe(dev, -ENODEV,
> + "fail to get irq %d\n",
> + isp4_ringbuf_interrupt_num[i]);
> + ret = devm_request_irq(&pdev->dev, irq, isp4_irq_handler, 0,
> + "ISP_IRQ", &pdev->dev);
> + if (ret)
> + return dev_err_probe(dev, ret, "fail to req irq %d\n",
> + irq);
> + }
> +
> + isp_dev->pltf_data = pdev->dev.platform_data;
> +
> + dev_dbg(dev, "isp irq registration successful\n");

Please leave this out.

> +
> + /* Link the media device within the v4l2_device */
> + isp_dev->v4l2_dev.mdev = &isp_dev->mdev;
> +
> + /* Initialize media device */
> + strscpy(isp_dev->mdev.model, "amd_isp41_mdev",
> + sizeof(isp_dev->mdev.model));
> + snprintf(isp_dev->mdev.bus_info, sizeof(isp_dev->mdev.bus_info),
> + "platform:%s", ISP4_DRV_NAME);
> + isp_dev->mdev.dev = &pdev->dev;
> + media_device_init(&isp_dev->mdev);
> +
> + /* register v4l2 device */
> + snprintf(isp_dev->v4l2_dev.name, sizeof(isp_dev->v4l2_dev.name),
> + "AMD-V4L2-ROOT");
> + ret = v4l2_device_register(&pdev->dev, &isp_dev->v4l2_dev);
> + if (ret)
> + return dev_err_probe(dev, ret,
> + "fail register v4l2 device\n");
> +
> + dev_dbg(dev, "AMD ISP v4l2 device registered\n");

This doesn't seem useful.

> +
> + ret = media_device_register(&isp_dev->mdev);
> + if (ret) {
> + dev_err(dev, "fail to register media device %d\n", ret);
> + goto err_unreg_v4l2;
> + }
> +
> + platform_set_drvdata(pdev, isp_dev);
> +
> + pm_runtime_set_suspended(dev);
> + pm_runtime_enable(dev);

You'll need to enable runtime PM before registering any interfaces on UAPI.
Same goes for setting driver data for the device.

> +
> + return 0;
> +
> +err_unreg_v4l2:
> + v4l2_device_unregister(&isp_dev->v4l2_dev);
> +
> + return dev_err_probe(dev, ret, "isp probe fail\n");
> +}
> +
> +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);
> + v4l2_device_unregister(&isp_dev->v4l2_dev);
> + dev_dbg(dev, "AMD ISP v4l2 device unregistered\n");

I'd say this is redundant.

> +}
> +
> +static struct platform_driver isp4_capture_drv = {
> + .probe = isp4_capture_probe,
> + .remove = isp4_capture_remove,
> + .driver = {
> + .name = ISP4_DRV_NAME,
> + .owner = THIS_MODULE,
> + }
> +};
> +
> +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");
> diff --git a/drivers/media/platform/amd/isp4/isp4.h b/drivers/media/platform/amd/isp4/isp4.h
> new file mode 100644
> index 000000000000..27a7362ce6f9
> --- /dev/null
> +++ b/drivers/media/platform/amd/isp4/isp4.h
> @@ -0,0 +1,35 @@
> +/* SPDX-License-Identifier: GPL-2.0+ */
> +/*
> + * Copyright (C) 2025 Advanced Micro Devices, Inc.
> + */
> +
> +#ifndef _ISP4_H_
> +#define _ISP4_H_
> +
> +#include <linux/mutex.h>
> +#include <media/v4l2-device.h>
> +#include <media/videobuf2-memops.h>
> +#include <media/videobuf2-vmalloc.h>
> +
> +#define ISP4_GET_ISP_REG_BASE(isp4sd) (((isp4sd))->mmio)
> +
> +struct isp4_platform_data {
> + void *adev;
> + void *bo;
> + void *cpu_ptr;
> + u64 gpu_addr;
> + u32 size;
> + u32 asic_type;
> + resource_size_t base_rmmio_size;
> +};
> +
> +struct isp4_device {
> + struct v4l2_device v4l2_dev;
> + struct media_device mdev;
> +
> + struct isp4_platform_data *pltf_data;
> + struct platform_device *pdev;
> + struct notifier_block i2c_nb;
> +};
> +
> +#endif /* isp4.h */

Use the same name as for the macro here, please.

--
Kind regards,

Sakari Ailus