Re: [PATCH 10/11] platform/x86: intel_cht_int33fe: Link with external dependencies using fwnodes

Andy Shevchenko
2019-04-08T16:42:52Z

On Wed, Apr 3, 2019 at 7:46 PM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> Supplying also external devices - the DisplayPort connector
> and the USB role switch - software fwnodes. After this the
> driver has access to all the components tied to the USB
> Type-C connector and can start creating software node
> references to actually associate them with the USB Type-C
> connector device.

> +static int role_switch_match(struct device *dev, void *name)
> +{
> + return !strcmp(dev_name(dev), name);
> +}
> +
> +static int cht_int33fe_setup_mux(struct cht_int33fe_data *data)
> +{

> + /* First let's find xHCI PCI device */
> + pdev = pci_get_class(PCI_CLASS_SERIAL_USB_XHCI, NULL);
> + if (!pdev || (pdev->vendor != PCI_VENDOR_ID_INTEL))
> + return -ENODEV;
> +

> + /* Then the child platform device */
> + p = device_find_child(&pdev->dev, "intel_xhci_usb_sw",
> + role_switch_match);

We have already similar code in kernel
(drivers/nvdimm/claim.c::namespace_match), perhaps
you at least can (locally) introduce

static int match_name(...) // or re-use from drivers/base/bus.c
{
...
}

static device_find_child_by_name(...)
{
...
}

which we may move to the driver core now or later on.

> + pci_dev_put(pdev);
> + if (!p)
> + return -EPROBE_DEFER;
> +

> + /* Finally the mux device */
> + dev = device_find_child(p, "intel_xhci_usb_sw-role-switch",
> + role_switch_match);

Ditto.

> + put_device(p);
> + if (!dev)
> + return -EPROBE_DEFER;

> + return 0;

> +}

> +static int cht_int33fe_setup_dp(struct cht_int33fe_data *data)
> +{
> + struct fwnode_handle *fwnode = data->node[INT33FE_NODE_DISPLAYPORT];
> + struct pci_dev *pdev;
> +
> + /* First let's find the GPU PCI device */
> + pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, NULL);
> + if (!pdev || (pdev->vendor != PCI_VENDOR_ID_INTEL))
> + return -ENODEV;
> +
> + /* Then the DP child device node */
> + data->dp = device_get_named_child_node(&pdev->dev, "DD02");
> + pci_dev_put(pdev);
> + if (!data->dp)
> + return -ENODEV;
> +

> + fwnode->secondary = ERR_PTR(-ENODEV);
> + data->dp->secondary = fwnode;

Can't generic helper be in charge of doing this, i.e. chaining fwnodes?

///
void fwnode_chain(parent, new)
{
...
}
///

fwnode_chain(data->dp, fwnode);

> +
> + return 0;
> +}

--
With Best Regards,
Andy Shevchenko