Re: [PATCH 04/11] media: iris: Add helper to create a context bank device on iris vpu bus

[Vishnu Reddy <busanna.reddy@oss.qualcomm.com>]

On 4/20/2026 11:26 PM, Dmitry Baryshkov wrote:
> On Mon, Apr 20, 2026 at 07:33:01PM +0530, Vishnu Reddy wrote:
>> On 4/17/2026 11:53 PM, Dmitry Baryshkov wrote:
>>> On Fri, Apr 17, 2026 at 08:49:44PM +0530, Vishnu Reddy wrote:
>>>> On 4/14/2026 8:48 PM, Dmitry Baryshkov wrote:
>>>>> On Tue, Apr 14, 2026 at 10:30:00AM +0530, Vishnu Reddy wrote:
>>>>>> From: Vikash Garodia<vikash.garodia@oss.qualcomm.com>
>>>>>>
>>>>>> Add a helper function to allocate and register context bank (CB) device
>>>>>> on the iris vpu bus. The function ID associated with the CB is specified
>>>>>> from the platform data, allowing the bus dma_configure callback to apply
>>>>>> correct stream ID mapping when device is registered.
>>>>>>
>>>>>> Signed-off-by: Vikash Garodia<vikash.garodia@oss.qualcomm.com>
>>>>>> Signed-off-by: Vishnu Reddy<busanna.reddy@oss.qualcomm.com>
>>>>>> ---
>>>>>>   drivers/media/platform/qcom/iris/iris_resources.c | 33 +++++++++++++++++++++++
>>>>>>   drivers/media/platform/qcom/iris/iris_resources.h |  1 +
>>>>>>   2 files changed, 34 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/media/platform/qcom/iris/iris_resources.c b/drivers/media/platform/qcom/iris/iris_resources.c
>>>>>> index 773f6548370a..a25e0f2e9d26 100644
>>>>>> --- a/drivers/media/platform/qcom/iris/iris_resources.c
>>>>>> +++ b/drivers/media/platform/qcom/iris/iris_resources.c
>>>>>> @@ -6,6 +6,7 @@
>>>>>>   #include <linux/clk.h>
>>>>>>   #include <linux/devfreq.h>
>>>>>>   #include <linux/interconnect.h>
>>>>>> +#include <linux/iris_vpu_bus.h>
>>>>>>   #include <linux/pm_domain.h>
>>>>>>   #include <linux/pm_opp.h>
>>>>>>   #include <linux/pm_runtime.h>
>>>>>> @@ -141,3 +142,35 @@ int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type
>>>>>>   	return 0;
>>>>>>   }
>>>>>> +
>>>>>> +static void iris_release_cb_dev(struct device *dev)
>>>>>> +{
>>>>>> +	kfree(dev);
>>>>>> +}
>>>>>> +
>>>>>> +struct device *iris_create_cb_dev(struct iris_core *core, const char *name, const u32 *f_id)
>>>>> Please move into the bus code and make it generic enough.
>>>> Do you suggest to add a wrapper to pass the varying inputs to the generic
>>>> bus, something like this
>>>> struct device* create_and_register_device(dma_mask, parent_dev, *release,
>>>> dev_name,...)
>>> Definitely not the release function. The devname is also not that
>>> important. The rest, yes, you are correct.
>>>
>>>>>> +{
>>>>>> +	struct device *dev;
>>>>>> +	int ret;
>>>>>> +
>>>>>> +	dev = kzalloc_obj(*dev);
>>>>>> +	if (!dev)
>>>>>> +		return ERR_PTR(-ENOMEM);
>>>>>> +
>>>>>> +	dev->release = iris_release_cb_dev;
>>>>>> +	dev->bus = &iris_vpu_bus_type;
>>>>>> +	dev->parent = core->dev;
>>>>>> +	dev->coherent_dma_mask = core->iris_platform_data->dma_mask;
>>>>>> +	dev->dma_mask = &dev->coherent_dma_mask;
>>>>> Would you also need to set the of_node? See
>>>>> device_set_of_node_from_dev()
>>>> It might be needed for FastRPC as they are following sub node approach, Iris
>>>> does not need.
>>> Wouldn't it save you from passing it to of_dma_configure_id()?
>> Iris will pass parent device of_node, setting parent device is enough.
> Set the of node and pass NULL to of_dma_configure_id.

Passing of_node as NULL to of_dma_configure_id() won’t map the SID to device,
If a dt sub node exists with iommus, the child’s of_node can be used.
Otherwise, the parent’s of_node must be passed with a valid function ID present
in iommu-map.

>>>>>> +
>>>>>> +	dev_set_name(dev, "%s", name);
>>>>>> +	dev_set_drvdata(dev, (void *)f_id);
>>>>>> +
>>>>>> +	ret = device_register(dev);
>>>>>> +	if (ret) {
>>>>>> +		put_device(dev);
>>>>>> +		return ERR_PTR(ret);
>>>>>> +	}
>>>>>> +
>>>>>> +	return dev;
>>>>>> +}
>>>>>> diff --git a/drivers/media/platform/qcom/iris/iris_resources.h b/drivers/media/platform/qcom/iris/iris_resources.h
>>>>>> index 6bfbd2dc6db0..4a494627ff23 100644
>>>>>> --- a/drivers/media/platform/qcom/iris/iris_resources.h
>>>>>> +++ b/drivers/media/platform/qcom/iris/iris_resources.h
>>>>>> @@ -15,5 +15,6 @@ int iris_unset_icc_bw(struct iris_core *core);
>>>>>>   int iris_set_icc_bw(struct iris_core *core, unsigned long icc_bw);
>>>>>>   int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type clk_type);
>>>>>>   int iris_prepare_enable_clock(struct iris_core *core, enum platform_clk_type clk_type);
>>>>>> +struct device *iris_create_cb_dev(struct iris_core *core, const char *name, const u32 *f_id);
>>>>>>   #endif
>>>>>>
>>>>>> -- 
>>>>>> 2.34.1
>>>>>>