Changeset View
Changeset View
Standalone View
Standalone View
share/man/man9/OF_device_from_xref.9
| Show All 26 Lines | |||||
| .\" | .\" | ||||
| .Dd April 9, 2018 | .Dd April 9, 2018 | ||||
| .Dt OF_DEVICE_FROM_XREF 9 | .Dt OF_DEVICE_FROM_XREF 9 | ||||
| .Os | .Os | ||||
| .Sh NAME | .Sh NAME | ||||
| .Nm OF_device_from_xref , | .Nm OF_device_from_xref , | ||||
| .Nm OF_xref_from_device , | .Nm OF_xref_from_device , | ||||
| .Nm OF_device_register_xref | .Nm OF_device_register_xref | ||||
| .Nm OF_device_unregister_xref | |||||
| .Nd "manage mappings between xrefs and devices" | .Nd "manage mappings between xrefs and devices" | ||||
| .Sh SYNOPSIS | .Sh SYNOPSIS | ||||
| .In dev/ofw/ofw_bus.h | .In dev/ofw/ofw_bus.h | ||||
| .In dev/ofw/ofw_bus_subr.h | .In dev/ofw/ofw_bus_subr.h | ||||
| .Ft int | .Ft int | ||||
| .Fn OF_device_register_xref "phandle_t xref" "device_t dev" | .Fn OF_device_register_xref "phandle_t xref" "device_t dev" | ||||
| .Ft void | |||||
| .Fn OF_device_unregister_xref "phandle_t xref" "device_t dev" | |||||
| .Ft device_t | .Ft device_t | ||||
| .Fn OF_device_from_xref "phandle_t xref" | .Fn OF_device_from_xref "phandle_t xref" | ||||
| .Ft phandle_t | .Ft phandle_t | ||||
| .Fn OF_xref_from_device "device_t dev" | .Fn OF_xref_from_device "device_t dev" | ||||
| .Sh DESCRIPTION | .Sh DESCRIPTION | ||||
| .Pp | .Pp | ||||
| When a device tree node references another node, the driver may | When a device tree node references another node, the driver may | ||||
| need to get a device_t instance associated with the referenced node. | need to get a device_t instance associated with the referenced node. | ||||
| For instance, an Ethernet driver accessing a PHY device. | For instance, an Ethernet driver accessing a PHY device. | ||||
| To make this possible, the kernel maintains a table that | To make this possible, the kernel maintains a table that | ||||
| maps effective handles to device_t instances. | maps effective handles to device_t instances. | ||||
| .Pp | .Pp | ||||
| .Fn OF_device_register_xref | .Fn OF_device_register_xref | ||||
| adds a map entry from the effective phandle | adds a map entry from the effective phandle | ||||
| .Fa xref | .Fa xref | ||||
| to device | to device | ||||
| .Fa dev . | .Fa dev . | ||||
| If a mapping entry for | If a mapping entry for | ||||
| .Fa xref | .Fa xref | ||||
| already exists, it is replaced with the new one. | already exists, it is replaced with the new one. | ||||
| The function always returns 0. | The function always returns 0. | ||||
| .Pp | |||||
| .Fn OF_device_unregister_xref | |||||
| removes a map entry from the effective phandle | |||||
| .Fa xref | |||||
| to device | |||||
| .Fa dev . | |||||
| If a mapping entry for | |||||
| .Fa xref | |||||
| does not exists, it silently returns. | |||||
| .Pp | .Pp | ||||
| .Fn OF_device_from_xref | .Fn OF_device_from_xref | ||||
| returns a device_t instance associated with the effective phandle | returns a device_t instance associated with the effective phandle | ||||
| .Fa xref . | .Fa xref . | ||||
| If no such mapping exists, the function returns NULL. | If no such mapping exists, the function returns NULL. | ||||
| .Pp | .Pp | ||||
| .Fn OF_xref_from_device | .Fn OF_xref_from_device | ||||
| returns the effective phandle associated with the device | returns the effective phandle associated with the device | ||||
| Show All 22 Lines | |||||