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Diffstat (limited to 'include/linux/pci-pwrctl.h')
-rw-r--r-- | include/linux/pci-pwrctl.h | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/include/linux/pci-pwrctl.h b/include/linux/pci-pwrctl.h new file mode 100644 index 000000000000..45e9cfe740e4 --- /dev/null +++ b/include/linux/pci-pwrctl.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2024 Linaro Ltd. + */ + +#ifndef __PCI_PWRCTL_H__ +#define __PCI_PWRCTL_H__ + +#include <linux/notifier.h> + +struct device; +struct device_link; + +/* + * This is a simple framework for solving the issue of PCI devices that require + * certain resources (regulators, GPIOs, clocks) to be enabled before the + * device can actually be detected on the PCI bus. + * + * The idea is to reuse the platform bus to populate OF nodes describing the + * PCI device and its resources, let these platform devices probe and enable + * relevant resources and then trigger a rescan of the PCI bus allowing for the + * same device (with a second associated struct device) to be registered with + * the PCI subsystem. + * + * To preserve a correct hierarchy for PCI power management and device reset, + * we create a device link between the power control platform device (parent) + * and the supplied PCI device (child). + */ + +/** + * struct pci_pwrctl - PCI device power control context. + * @dev: Address of the power controlling device. + * + * An object of this type must be allocated by the PCI power control device and + * passed to the pwrctl subsystem to trigger a bus rescan and setup a device + * link with the device once it's up. + */ +struct pci_pwrctl { + struct device *dev; + + /* Private: don't use. */ + struct notifier_block nb; + struct device_link *link; +}; + +int pci_pwrctl_device_set_ready(struct pci_pwrctl *pwrctl); +void pci_pwrctl_device_unset_ready(struct pci_pwrctl *pwrctl); +int devm_pci_pwrctl_device_set_ready(struct device *dev, + struct pci_pwrctl *pwrctl); + +#endif /* __PCI_PWRCTL_H__ */ |