[PATCH 08/13] i3c: mipi-i3c-hci-pci: Allocate a structure for mipi_i3c_hci_pci device information

[Adrian Hunter]

On 12/11/2025 22:17, Frank Li wrote:
> On Wed, Nov 12, 2025 at 09:25:14PM +0200, Adrian Hunter wrote:
>> On 12/11/2025 18:41, Frank Li wrote:
>>> On Wed, Nov 12, 2025 at 12:03:34PM +0200, Adrian Hunter wrote:
>>>> Allocate a structure for mipi_i3c_hci_pci device information, in
>>>> preparation for additional changes that need to store mipi_i3c_hci_pci
>>>> device-specific information.
>>>>
>>>> Signed-off-by: Adrian Hunter <adrian.hunter at intel.com>
>>>> ---
>>>>  .../master/mipi-i3c-hci/mipi-i3c-hci-pci.c    | 29 ++++++++++++-------
>>>>  1 file changed, 19 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>>>> index b3b6b6f43af2..9fa89af7479f 100644
>>>> --- a/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>>>> +++ b/drivers/i3c/master/mipi-i3c-hci/mipi-i3c-hci-pci.c
>>>> @@ -14,6 +14,10 @@
>>>>  #include <linux/pci.h>
>>>>  #include <linux/platform_device.h>
>>>>
>>>> +struct mipi_i3c_hci_pci {
>>>> +	struct platform_device *pdev;
>>>> +};
>>>> +
>>>
>>> Is it simpler by using platform_device_register_data(), pass down platform
>>> related information by void *data?
>>
>> No, this is just a normal allocated structure for the PCI driver
>> (mipi_i3c_hci_pci) to put information related to the PCI device.
>> It is later used to store the current Latency Tolerance Reporting (LTR)
>> register values.
> 
> Is it static value, or does it change after boot in other words?

Dynamic

> 
>>
>> So it is not the same thing as platform_data.
> 
> Base on your code to create platform data is duplicate what's did by
> platform_device_register_data().

It is not platform data

> 
> The pci device create platform devices,  platform driver should not use
> pci's information directly. platform driver should be reused if it probe
> from acpi or dt-tree.
> 
> I think it'd better pass down platform data information, which can include
> callback to fetch needed information for difference's parent devices.

PCI Latency Tolerance Reporting (LTR) has nothing to do with I3C
or the platform device, so it does not belong in the platform driver.

> 
> Frank
> 
>>
>>>
>>> Frank
>>>>  struct mipi_i3c_hci_pci_info {
>>>>  	int (*init)(struct pci_dev *pci);
>>>>  };
>>>> @@ -71,10 +75,14 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>>>>  				  const struct pci_device_id *id)
>>>>  {
>>>>  	const struct mipi_i3c_hci_pci_info *info;
>>>> -	struct platform_device *pdev;
>>>> +	struct mipi_i3c_hci_pci *hci;
>>>>  	struct resource res[2];
>>>>  	int dev_id, ret;
>>>>
>>>> +	hci = devm_kzalloc(&pci->dev, sizeof(*hci), GFP_KERNEL);
>>>> +	if (!hci)
>>>> +		return -ENOMEM;
>>>> +
>>>>  	ret = pcim_enable_device(pci);
>>>>  	if (ret)
>>>>  		return ret;
>>>> @@ -95,14 +103,14 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>>>>  	if (dev_id < 0)
>>>>  		return dev_id;
>>>>
>>>> -	pdev = platform_device_alloc("mipi-i3c-hci", dev_id);
>>>> -	if (!pdev)
>>>> +	hci->pdev = platform_device_alloc("mipi-i3c-hci", dev_id);
>>>> +	if (!hci->pdev)
>>>>  		return -ENOMEM;
>>>>
>>>> -	pdev->dev.parent = &pci->dev;
>>>> -	device_set_node(&pdev->dev, dev_fwnode(&pci->dev));
>>>> +	hci->pdev->dev.parent = &pci->dev;
>>>> +	device_set_node(&hci->pdev->dev, dev_fwnode(&pci->dev));
>>>>
>>>> -	ret = platform_device_add_resources(pdev, res, ARRAY_SIZE(res));
>>>> +	ret = platform_device_add_resources(hci->pdev, res, ARRAY_SIZE(res));
>>>>  	if (ret)
>>>>  		goto err;
>>>>
>>>> @@ -113,23 +121,24 @@ static int mipi_i3c_hci_pci_probe(struct pci_dev *pci,
>>>>  			goto err;
>>>>  	}
>>>>
>>>> -	ret = platform_device_add(pdev);
>>>> +	ret = platform_device_add(hci->pdev);
>>>>  	if (ret)
>>>>  		goto err;
>>>>
>>>> -	pci_set_drvdata(pci, pdev);
>>>> +	pci_set_drvdata(pci, hci);
>>>>
>>>>  	return 0;
>>>>
>>>>  err:
>>>> -	platform_device_put(pdev);
>>>> +	platform_device_put(hci->pdev);
>>>>  	ida_free(&mipi_i3c_hci_pci_ida, dev_id);
>>>>  	return ret;
>>>>  }
>>>>
>>>>  static void mipi_i3c_hci_pci_remove(struct pci_dev *pci)
>>>>  {
>>>> -	struct platform_device *pdev = pci_get_drvdata(pci);
>>>> +	struct mipi_i3c_hci_pci *hci = pci_get_drvdata(pci);
>>>> +	struct platform_device *pdev = hci->pdev;
>>>>  	int dev_id = pdev->id;
>>>>
>>>>  	platform_device_unregister(pdev);
>>>> --
>>>> 2.51.0
>>>>
>>>>
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>>
>>
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