freebsd-skq/sys/dev/fdt/fdt_clock_if.m
ian 944d759ab7 Create an interface for drivers to enable or disable their clocks as listed
in the clocks=<...> properties of their FDT data.  The clock properties
consist of 2-cell tuples, each containing a clock device node reference and
a clock number.  A clock device driver can register itself as providing
this interface, then other drivers can turn the FDT clock node reference
into the corresponding device_t so that they can use the interface to query
and manipulate their clocks.

This provides convenience functions to enable or disable all the clocks
listed in the properties for a device, so most drivers will be able to
manage their clocks with a single call to fdt_clock_enable_all(dev).
2014-09-02 03:23:05 +00:00

82 lines
2.3 KiB
Objective-C

#-
# Copyright (c) 2014 Ian Lepore
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
# notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# $FreeBSD$
#
#include <sys/types.h>
#
# This is the interface that fdt_clock drivers provide to other drivers.
# In this context, clock refers to a clock signal provided to some other
# hardware component within the system. They are most often found within
# embedded processors that have on-chip IO controllers.
#
INTERFACE fdt_clock;
HEADER {
enum {
FDT_CIFLAG_RUNNING = 0x01,
};
struct fdt_clock_info {
device_t provider;
uint32_t index;
const char * name; /* May be "", will not be NULL. */
uint32_t flags;
uint64_t frequency; /* In Hz. */
};
}
#
# Enable the specified clock.
# Returns 0 on success or a standard errno value.
#
METHOD int enable {
device_t provider;
int index;
};
#
# Disable the specified clock.
# Returns 0 on success or a standard errno value.
#
METHOD int disable {
device_t provider;
int index;
};
#
# Returns information about the current operational state of specified clock.
#
METHOD int get_info {
device_t provider;
int index;
struct fdt_clock_info *info;
};