Re: [PATCH v5 2/4] fpga pr ip: Core driver support for Altera Partial Reconfiguration IP.

From: Anatolij Gustschin
Date: Wed Mar 22 2017 - 12:41:01 EST


Hi Matthew,

On Wed, 22 Mar 2017 09:08:18 -0700 (PDT)
matthew.gerlach@xxxxxxxxxxxxxxx matthew.gerlach@xxxxxxxxxxxxxxx wrote:
...
>> Can we also add a function for registering a PCIe device with
>> PR IP here? Something like:
>
>If we have an alt_pr_pcie_register function, we will need the
>corresponding alt_pr_pcie_unregister function. Both of these functions
>should go into their own file like alt_pr_platform_probe() and
>alt_pr_platform_remove().

Okay, thanks.

>> /**
>> * alt_pr_pcie_register - register PCIe device with PR-IP core
>> * @pci_dev: PCI device with PR-IP
>> * @bar: PR-IP BAR number
>> * @pr_offset: offset of the PR-IP core registers
>> *
>> * Return: 0 on success, negative error code otherwise.
>> *
>> * To unregister the PCIe device, use alt_pr_unregister(&pdev->dev).
>> */
>> int alt_pr_pcie_register(struct pci_dev *pdev, int bar, int pr_offset)
>> {
>> void __iomem *base;
>> int ret;
>>
>> if (!pci_is_enabled(pdev)) {
>> ret = pci_enable_device(pdev);
>> if (ret < 0) {
>> dev_err(&pdev->dev, "can't enable device: %d\n", ret);
>> return ret;
>> }
>> }
>>
>> base = devm_ioremap_resource(&pdev->dev, &pdev->resource[bar]);
>
>Does this remap the whole bar? If it does, what happens if other
>components are also connected to the bar? How do those corresponding
>drivers get access to the mapped memory?

yes, it remaps the whole bar. I do not know the details of the PR IP,
my assumption was that PR IP it is only one component in the bar.
Then I could use devm_ioremap() instead. Thanks for the hint!

Anatolij