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

[Dmitry Baryshkov]

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@xxxxxxxxxxxxxxxx>
> >>>>
> >>>> 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@xxxxxxxxxxxxxxxx>
> >>>> Signed-off-by: Vishnu Reddy<busanna.reddy@xxxxxxxxxxxxxxxx>
> >>>> ---
> >>>>   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.

> >>>> +
> >>>> +	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
> >>>>

-- 
With best wishes
Dmitry