Re: [PATCH v4 1/7] media: platform: amd: Introduce amd isp4 capture driver
From: Du, Bin
Date: Tue Sep 23 2025 - 03:56:50 EST
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@xxxxxxx>
Signed-off-by: Svetoslav Stoilov <Svetoslav.Stoilov@xxxxxxx>
Signed-off-by: Bin Du <Bin.Du@xxxxxxx>
Reviewed-by: Mario Limonciello (AMD) <superm1@xxxxxxxxxx>
Tested-by: Alexey Zagorodnikov <xglooom@xxxxxxxxx>
[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