Re: [PATCH v4 1/7] media: platform: amd: Introduce amd isp4 capture driver

["Du, Bin" <bin.du@amd.com>]

Many thanks Sultan for your careful review.

On 9/22/2025 4:23 AM, Sultan Alsawaf wrote:
> Hi Bin,
> 
> On Thu, Sep 11, 2025 at 06:08:41PM +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
>> MAINTAINERS file
>>
>> 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>
>> Tested-by: Alexey Zagorodnikov <xglooom@gmail.com>
> 
> [snip]
> 
>> +++ b/drivers/media/platform/amd/isp4/Kconfig
>> @@ -0,0 +1,13 @@
>> +# SPDX-License-Identifier: GPL-2.0+
>> +
>> +config AMD_ISP4
>> +	tristate "AMD ISP4 and camera driver"
>> +	depends on VIDEO_DEV && VIDEO_V4L2_SUBDEV_API && DRM_AMD_ISP
>> +	select VIDEOBUF2_CORE
>> +	select VIDEOBUF2_V4L2
>> +	select VIDEOBUF2_MEMOPS
> 
> VIDEO_V4L2_SUBDEV_API should be selected rather than set as a dependency, per
> what other drivers do. You can also sort the dependencies to look cleaner.
> 
> Change to:
> 
> 	depends on VIDEO_DEV && DRM_AMD_ISP
> 	select VIDEOBUF2_CORE
> 	select VIDEOBUF2_MEMOPS
> 	select VIDEOBUF2_V4L2
> 	select VIDEO_V4L2_SUBDEV_API
> 

Sure, will change VIDEO_V4L2_SUBDEV_API from depends to select. Had a 
check, yes, you are correct, almost all driver are doing like this with 
only one exception drivers/media/platform/ti/Kconfig

>> +	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.
> 
> [snip]
> 
>> +++ b/drivers/media/platform/amd/isp4/isp4.c
>> @@ -0,0 +1,121 @@
>> +// 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 VIDEO_BUF_NUM 5
>> +
>> +#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))
> 
> The unnecessary cast on container_of() is removed later in "[PATCH v4 4/7]
> media: platform: amd: isp4 subdev and firmware loading handling added".
> 
> Remove the cast in this patch instead.
> 

Sure, will remove it directly from this patch

>> +
>> +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;
>> +	struct isp4_device *isp_dev;
>> +	int i, irq, ret;
>> +
>> +	isp_dev = devm_kzalloc(&pdev->dev, sizeof(*isp_dev), GFP_KERNEL);
> 
> s/&pdev->dev/dev/
> 

Sure, will update in the next version.

>> +	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]);
> 
> Return the error from platform_get_irq() here instead of -ENODEV.
> 

Thanks, will update in the next version.

>> +		ret = devm_request_irq(&pdev->dev, irq, isp4_irq_handler, 0,
>> +				       "ISP_IRQ", &pdev->dev);
> 
> s/&pdev->dev/dev/
> 

Sure, will update in the next version.

>> +		if (ret)
>> +			return dev_err_probe(dev, ret, "fail to req irq %d\n",
>> +					     irq);
>> +	}
>> +
>> +	/* 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;
> 
> s/&pdev->dev/dev/
> 

Sure, will update in the next version.

>> +	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);
> 
> s/&pdev->dev/dev/
> 

Sure, will update in the next version.

>> +	if (ret)
>> +		return dev_err_probe(dev, ret,
>> +				     "fail register v4l2 device\n");
>> +
>> +	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);
>> +
>> +	return 0;
>> +
>> +err_unreg_v4l2:
>> +	v4l2_device_unregister(&isp_dev->v4l2_dev);
>> +
>> +	return dev_err_probe(dev, ret, "isp probe fail\n");
>> +}
> 
> [snip]
> 
>> +++ b/drivers/media/platform/amd/isp4/isp4.h
>> @@ -0,0 +1,24 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * Copyright (C) 2025 Advanced Micro Devices, Inc.
>> + */
>> +
>> +#ifndef _ISP4_H_
>> +#define _ISP4_H_
>> +
>> +#include <linux/mutex.h>
> 
> Remove this linux/mutex.h include. It should be moved to isp4_subdev.h instead.
> 

Sure, will update in the next version.

>> +#include <media/v4l2-device.h>
>> +#include <media/videobuf2-memops.h>
>> +#include <media/videobuf2-vmalloc.h>
> 
> This media/videobuf2-vmalloc.h include is removed in "[PATCH v4 4/7] media:
> platform: amd: isp4 subdev and firmware loading handling added".
> 
> Remove it in this patch instead.
> 

Sure, will remove it directly from this patch.

>> +
>> +#define ISP4_GET_ISP_REG_BASE(isp4sd) (((isp4sd))->mmio)
>> +
>> +struct isp4_device {
>> +	struct v4l2_device v4l2_dev;
>> +	struct media_device mdev;
>> +
>> +	struct platform_device *pdev;
>> +	struct notifier_block i2c_nb;
> 
> i2c_nb is unused, remove it.
> 

Sure, will remove it and other unused fields in this struct.

>> +};
>> +
>> +#endif /* _ISP4_H_ */
>> -- 
>> 2.34.1
>>
> 
> Sultan

-- 
Regards,
Bin