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ofw_bus_is_compatible(9) FreeBSD Kernel Developer's Manual
NAME
ofw_bus_is_compatible, ofw_bus_is_compatible_strict,
ofw_bus_node_is_compatible, ofw_bus_search_compatible - check device tree
nodes for compatibility with drivers
SYNOPSIS
#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
int
ofw_bus_is_compatible(device_t dev, const char *compatstr);
int
ofw_bus_is_compatible_strict(device_t dev, const char *compatstr);
int
ofw_bus_node_is_compatible(phandle_t node, const char *compatstr);
const struct ofw_compat_data *
ofw_bus_search_compatible(device_t dev,
const struct ofw_compat_data *compat);
DESCRIPTION
The "compatible" property of the device tree node is used to identify the
type of the device the node represents. The property is a list of one or
more strings that represent hardware types the device is compatible with.
The common format for such strings is "vendor,hardware" where "vendor" is
an abbreviated name of the manufacturer and "hardware" is a device
identifier, for instance, "fsl" for "Freescale" and "imx6ul-i2c" for the
I2C controller. More than one string is required for compatibility with
older revisions of the driver. If hardware revision B is backward
compatible with revision A device tree node can signal this compatibility
by providing both "vndr,hrdwrA" and "vndr,hrdwrB" strings in the
"compatibile" property value. This way older driver can use features
available only in revision A, and the new version of the driver can take
advantage of revision B feature set.
ofw_bus_is_compatible() returns 1 if the compatstr value occurs in the
"compatible" property list of the device tree node associated with the
device dev, and 0 otherwise.
ofw_bus_is_compatible_strict() return 1 if the "compatible" property of
the device tree node associated with the device dev consists of only one
string and this string is equal to compatstr, and 0 otherwise.
ofw_bus_node_is_compatible() returns 1 if the compatstr value occurs in
the "compatible" property list of the device tree node node, and 0
otherwise.
ofw_bus_search_compatible() returns pointer to the first entry of the
compat table whose ocd_str field occurs in "compatible" property of the
device tree node associated with the device dev. The compat table is an
array of struct ofw_compat_data elements defined as follows:
struct ofw_compat_data {
const char *ocd_str;
static struct ofw_compat_data compat_data[] = {
{"arm,hrdwrA", FEATURE_A},
{"arm,hrdwrB", FEATURE_A | FEATURE_B},
{NULL, 0}
};
static int
hrdwr_probe(device_t dev)
{
...
if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
return (ENXIO);
...
}
static int
hrdwr_attach(device_t dev)
{
...
sc = device_get_softc(dev);
sc->sc_features = ofw_bus_search_compatible(dev, compat_data)->ocd_data;
...
}
SEE ALSO
ofw_bus_find_compatible(9)
AUTHORS
This manual page was written by Oleksandr Tymoshenko.
FreeBSD 14.0-RELEASE-p6 April 8, 2018 FreeBSD 14.0-RELEASE-p6