| Message ID | 20241022-pci-pwrctl-rework-v1-2-94a7e90f58c5@linaro.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI/pwrctl: Ensure that the pwrctl drivers are probed before PCI client drivers | expand |
On Tue, 22 Oct 2024 at 12:28, Manivannan Sadhasivam via B4 Relay <devnull+manivannan.sadhasivam.linaro.org@kernel.org> wrote: > > From: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > > Currently, pwrctl devices are created if the corresponding PCI nodes are > defined in devicetree. But this is not correct, because not all PCI nodes > defined in devicetree require pwrctl support. Pwrctl comes into picture > only when the device requires kernel to manage its power state. This can > be determined using the power supply properties present in the devicetree > node of the device. > > So add a new API, of_pci_is_supply_present() that checks the devicetree > node if at least one power supply property is present or not. If present, > then the pwrctl device will be created for that PCI node. Otherwise, it > will be skipped. > > Cc: stable+noautosel@kernel.org # Depends on of_platform_device_create() rework > Fixes: 8fb18619d910 ("PCI/pwrctl: Create platform devices for child OF nodes of the port node") > Suggested-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org> > --- Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c index 959044b059b5..698ec98b9388 100644 --- a/drivers/pci/bus.c +++ b/drivers/pci/bus.c @@ -354,6 +354,17 @@ void pci_bus_add_device(struct pci_dev *dev) if (dev_of_node(&dev->dev) && pci_is_bridge(dev)) { for_each_child_of_node_scoped(dn, child) { + /* + * First check whether the pwrctl device needs to be + * created or not. This is decided based on at least + * one of the power supplies being defined in the + * devicetree node of the device. + */ + if (!of_pci_is_supply_present(child)) { + pci_dbg(dev, "skipping OF node: %s\n", child->name); + continue; + } + pdev = of_platform_device_create(child, NULL, &dev->dev); if (!pdev) pci_err(dev, "failed to create OF node: %s\n", child->name); diff --git a/drivers/pci/of.c b/drivers/pci/of.c index dacea3fc5128..1f6a15a35a82 100644 --- a/drivers/pci/of.c +++ b/drivers/pci/of.c @@ -728,6 +728,33 @@ void of_pci_make_dev_node(struct pci_dev *pdev) } #endif +/** + * of_pci_is_supply_present() - Check if the power supply is present for the PCI + * device + * @np: Device tree node + * + * Check if the power supply for the PCI device is present in the device tree + * node or not. + * + * Return: true if at least one power supply exists; false otherwise. + */ +bool of_pci_is_supply_present(struct device_node *np) +{ + struct property *prop; + char *supply; + + if (!np) + return false; + + for_each_property_of_node(np, prop) { + supply = strrchr(prop->name, '-'); + if (supply && !strcmp(supply, "-supply")) + return true; + } + + return false; +} + #endif /* CONFIG_PCI */ /** diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 14d00ce45bfa..c8081b427267 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -746,6 +746,7 @@ void pci_set_bus_of_node(struct pci_bus *bus); void pci_release_bus_of_node(struct pci_bus *bus); int devm_of_pci_bridge_init(struct device *dev, struct pci_host_bridge *bridge); +bool of_pci_is_supply_present(struct device_node *np); #else static inline int @@ -793,6 +794,10 @@ static inline int devm_of_pci_bridge_init(struct device *dev, struct pci_host_br return 0; } +static inline bool of_pci_is_supply_present(struct device_node *np); +{ + return false; +} #endif /* CONFIG_OF */ struct of_changeset;