Re: [PATCH v2 3/7] media: iris: add iris vpu bus support and register it with iommu_buses

[Dmitry Baryshkov]

On Fri, Feb 27, 2026 at 07:41:19PM +0530, Vikash Garodia wrote:
> Add iris vpu bus support and hooks the new bus into the iommu_buses
> list. Iris devices need their own bus so that each iris device can run
> its own dma_configure() logic.

What are "Iris devices"? Are there multiple en/decoders in an SoC?

> 
> Co-developed-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
> ---
>  drivers/iommu/iommu.c                           |  4 ++++
>  drivers/media/platform/qcom/iris/Makefile       |  4 ++++
>  drivers/media/platform/qcom/iris/iris_vpu_bus.c | 32 +++++++++++++++++++++++++
>  include/linux/iris_vpu_bus.h                    | 13 ++++++++++
>  4 files changed, 53 insertions(+)
> 
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 35db5178095404fec87cd0f18e44ea97cf354e78..fd5fb7c10da22ab548d359ca1f44504acc3d646c 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -13,6 +13,7 @@
>  #include <linux/bug.h>
>  #include <linux/types.h>
>  #include <linux/init.h>
> +#include <linux/iris_vpu_bus.h>
>  #include <linux/export.h>
>  #include <linux/slab.h>
>  #include <linux/errno.h>
> @@ -178,6 +179,9 @@ static const struct bus_type * const iommu_buses[] = {
>  #ifdef CONFIG_CDX_BUS
>  	&cdx_bus_type,
>  #endif
> +#if IS_ENABLED(CONFIG_VIDEO_QCOM_IRIS)
> +	&iris_vpu_bus_type,
> +#endif
>  };
>  
>  /*
> diff --git a/drivers/media/platform/qcom/iris/Makefile b/drivers/media/platform/qcom/iris/Makefile
> index 2abbd3aeb4af07e52bf372a4b2f352463529c92c..6f4052b98491aeddc299669334d4c93e9a3420e4 100644
> --- a/drivers/media/platform/qcom/iris/Makefile
> +++ b/drivers/media/platform/qcom/iris/Makefile
> @@ -31,3 +31,7 @@ qcom-iris-objs += iris_platform_gen1.o
>  endif
>  
>  obj-$(CONFIG_VIDEO_QCOM_IRIS) += qcom-iris.o
> +
> +ifdef CONFIG_VIDEO_QCOM_IRIS
> +obj-y += iris_vpu_bus.o
> +endif
> diff --git a/drivers/media/platform/qcom/iris/iris_vpu_bus.c b/drivers/media/platform/qcom/iris/iris_vpu_bus.c
> new file mode 100644
> index 0000000000000000000000000000000000000000..34ce78d9b0ff1feda15ba4f060a56d02749a0858
> --- /dev/null
> +++ b/drivers/media/platform/qcom/iris/iris_vpu_bus.c
> @@ -0,0 +1,32 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2026 Qualcomm Innovation Center, Inc. All rights reserved.

Drop the year.

> + */
> +
> +#include <linux/device.h>
> +#include <linux/of_device.h>
> +
> +#include "iris_platform_common.h"
> +
> +static int iris_vpu_bus_dma_configure(struct device *dev)
> +{
> +	struct iris_context_bank *cb = dev_get_drvdata(dev);
> +
> +	if (!cb)
> +		return -ENODEV;
> +
> +	return of_dma_configure_id(dev, dev->parent->of_node, true, &cb->f_id);
> +}
> +
> +const struct bus_type iris_vpu_bus_type = {
> +	.name = "iris-bus",
> +	.dma_configure = iris_vpu_bus_dma_configure,
> +};
> +EXPORT_SYMBOL_GPL(iris_vpu_bus_type);
> +
> +static int __init iris_vpu_bus_init(void)
> +{
> +	return bus_register(&iris_vpu_bus_type);

Together with the Host1x it's the third bus having exactly the same
functionality that I've seen in the last several days (I counted the
FastRPC one). Could you please generalize Tegra code and come up with
the single bug that will work for all simple users?

> +}
> +
> +postcore_initcall(iris_vpu_bus_init);
> diff --git a/include/linux/iris_vpu_bus.h b/include/linux/iris_vpu_bus.h
> new file mode 100644
> index 0000000000000000000000000000000000000000..8aba472fcadd269e196b7243da5660deaff31abb
> --- /dev/null
> +++ b/include/linux/iris_vpu_bus.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-only
> + *
> + * Copyright (c) 2026 Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#ifndef __IRIS_VPU_BUS_H__
> +#define __IRIS_VPU_BUS_H__
> +
> +#if IS_ENABLED(CONFIG_VIDEO_QCOM_IRIS)
> +extern const struct bus_type iris_vpu_bus_type;
> +#endif
> +
> +#endif /* __IRIS_VPU_BUS_H__ */
> 
> -- 
> 2.34.1
> 

-- 
With best wishes
Dmitry