NAME
OF_device_from_xref, OF_xref_from_device, OF_device_register_xref — manage mappings between xrefs and devicesSYNOPSIS
#include <dev/ofw/ofw_bus.h>#include <dev/ofw/ofw_bus_subr.h> int
OF_device_register_xref(phandle_t xref, device_t dev); device_t
OF_device_from_xref(phandle_t xref); phandle_t
OF_xref_from_device(device_t dev);
DESCRIPTION
When a device tree node references another node, the driver may need to get a device_t instance associated with the referenced node. For instance, an Ethernet driver accessing a PHY device. To make this possible, the kernel maintains a table that maps effective handles to device_t instances. OF_device_register_xref() adds a map entry from the effective phandle xref to device dev. If a mapping entry for xref already exists, it is replaced with the new one. The function always returns 0. OF_device_from_xref() returns a device_t instance associated with the effective phandle xref. If no such mapping exists, the function returns NULL. OF_xref_from_device() returns the effective phandle associated with the device dev. If no such mapping exists, the function returns 0.EXAMPLES
static int
acmephy_attach(device_t dev)
{
phandle_t node;
/* PHY node is referenced from eth device, register it */
node = ofw_bus_get_node(dev);
OF_device_register_xref(OF_xref_from_node(node), dev);
return (0);
}
SEE ALSO
OF_node_to_xref(9)AUTHORS
This manual page was written by Oleksandr Tymoshenko <[email protected]>.| April 9, 2018 | Debian |