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 4/14/2026 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,...)
>> +{
>> +	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.
>> +
>> +	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
>>