Re: [PATCH v3 3/7] media: iris: add iris vpu bus support and register it with iommu_buses

[Dmitry Baryshkov]

On Fri, Mar 13, 2026 at 06:49:37PM +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 they can run their own
> dma_configure() logic.
> 
> 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 +++
>  .../platform/qcom/iris/iris_platform_common.h      |  6 ++++
>  drivers/media/platform/qcom/iris/iris_vpu_bus.c    | 32 ++++++++++++++++++++++
>  include/linux/iris_vpu_bus.h                       | 13 +++++++++
>  5 files changed, 59 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_platform_common.h b/drivers/media/platform/qcom/iris/iris_platform_common.h
> index 5a489917580eb10022fdcb52f7321a915e8b239d..2273243d1a80446233dd82dcd77444aa043ad064 100644
> --- a/drivers/media/platform/qcom/iris/iris_platform_common.h
> +++ b/drivers/media/platform/qcom/iris/iris_platform_common.h
> @@ -204,6 +204,12 @@ struct icc_vote_data {
>  	u32 fps;
>  };
>  
> +struct iris_context_bank {
> +	char *name;

const

> +	u32 f_id;
> +	u32 region_mask;

Unused here

> +};
> +
>  enum platform_pm_domain_type {
>  	IRIS_CTRL_POWER_DOMAIN,
>  	IRIS_HW_POWER_DOMAIN,
> 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..9e9fdeb6e405aab26ecf5e57ca91fca6b8eda2c5
> --- /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) Qualcomm Innovation Center, Inc. All rights reserved.
> + */
> +
> +#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);
> +}

There is nothing Iris-specific here. Can we please turn this into a
generic code (ideally also shared with host1x)?

> +
> +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);
> +}
> +
> +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..422898cdf2f62eb7f4583d970a01c8776dd12164
> --- /dev/null
> +++ b/include/linux/iris_vpu_bus.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0-only
> + *
> + * Copyright (c) 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