On Wed, Feb 8, 2023 at 11:00 AM Binbin Zhou <zhoubinbin@xxxxxxxxxxx> wrote:
>
>
> 在 2022/11/17 10:09, Liu Peibao 写道:
> > Add a mechanism to disable on chip PCI devices by DT. Typically, when there
> > are pins shareable between the platform device and the on chip PCI device,
> > if the PCI device is not preferred, add `status = "disabled"` property to
> > this PCI device DT node.
> >
> > For example, on LS2K1000, GMAC1 (on chip PCI device) and GPIO (platform
> > device, not PCI device) 14 share the same pin. If GMAC1 is not preferred,
> > add `status = "disabled"` property in GMAC1 DT node.
> >
> > Signed-off-by: Liu Peibao <liupeibao@xxxxxxxxxxx>
> Tested-by: Binbin Zhou <zhoubinbin@xxxxxxxxxxx>
Acked-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
> > ---
> > V5 -> V6: 1. rewrite the commit log to make things clear.
> > 2. replace "unavailable" as "disabled" in patch subject.
> > V4 -> V5: clear the issue we are facing in commit log.
> > V3 -> V4: 1. get rid of the masklist and search the status property
> > directly.
> > 2. check the status property only when accessing the vendor ID.
> > V2 -> V3: 1. use list_for_each_entry() for more clearly.
> > 2. fix wrong use of sizeof().
> > V1 -> V2: use existing property "status" instead of adding new property.
> >
> > drivers/pci/controller/pci-loongson.c | 11 +++++++++++
> > 1 file changed, 11 insertions(+)
> >
> > diff --git a/drivers/pci/controller/pci-loongson.c b/drivers/pci/controller/pci-loongson.c
> > index 05c50408f13b..efca0b3b5a29 100644
> > --- a/drivers/pci/controller/pci-loongson.c
> > +++ b/drivers/pci/controller/pci-loongson.c
> > @@ -194,6 +194,17 @@ static void __iomem *pci_loongson_map_bus(struct pci_bus *bus,
> > return NULL;
> > }
> >
> > +#ifdef CONFIG_OF
> > + /* Don't access disabled devices. */
> > + if (pci_is_root_bus(bus) && where == PCI_VENDOR_ID) {
> > + struct device_node *dn;
> > +
> > + dn = of_pci_find_child_device(bus->dev.of_node, devfn);
> > + if (dn && !of_device_is_available(dn))
> > + return NULL;
> > + }
> > +#endif
> > +
> > /* CFG0 can only access standard space */
> > if (where < PCI_CFG_SPACE_SIZE && priv->cfg0_base)
> > return cfg0_map(priv, bus, devfn, where);
>
