freebsd-dev/sys/dev/pwm/ofw_pwm.c
Emmanuel Vadot 9312900f6d Add a pwm subsystem so we can configure pwm controller from kernel and userland.
The pwm subsystem consist of API for PWM controllers, pwmbus to register them
and a pwm(8) utility to talk to them from userland.

Reviewed by:	oshgobo (capsicum), bcr (manpage), 0mp (manpage)
Differential Revision:	https://reviews.freebsd.org/D17938
2018-12-12 20:56:56 +00:00

110 lines
3.1 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2018 Emmanuel Vadot <manu@FreeBSD.org>
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/resource.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/pwm/pwmbus.h>
#include "pwm_if.h"
int
pwm_get_by_ofw_propidx(device_t consumer, phandle_t node,
const char *prop_name, int idx, pwm_channel_t *out_channel)
{
phandle_t xref;
pcell_t *cells;
struct pwm_channel channel;
int ncells, rv;
rv = ofw_bus_parse_xref_list_alloc(node, prop_name, "#pwm-cells",
idx, &xref, &ncells, &cells);
if (rv != 0)
return (rv);
channel.dev = OF_device_from_xref(xref);
if (channel.dev == NULL) {
OF_prop_free(cells);
return (ENODEV);
}
channel.busdev = PWM_GET_BUS(channel.dev);
if (channel.busdev == NULL) {
OF_prop_free(cells);
return (ENODEV);
}
channel.channel = cells[0];
channel.period = cells[1];
if (ncells >= 3)
channel.flags = cells[2];
*out_channel = malloc(sizeof(struct pwm_channel), M_DEVBUF, M_WAITOK | M_ZERO);
**out_channel = channel;
return (0);
}
int
pwm_get_by_ofw_idx(device_t consumer, phandle_t node, int idx,
pwm_channel_t *out_channel)
{
return (pwm_get_by_ofw_propidx(consumer, node, "pwms", idx, out_channel));
}
int
pwm_get_by_ofw_property(device_t consumer, phandle_t node,
const char *prop_name, pwm_channel_t *out_channel)
{
return (pwm_get_by_ofw_propidx(consumer, node, prop_name, 0, out_channel));
}
int
pwm_get_by_ofw_name(device_t consumer, phandle_t node, const char *name,
pwm_channel_t *out_channel)
{
int rv, idx;
rv = ofw_bus_find_string_index(node, "pwm-names", name, &idx);
if (rv != 0)
return (rv);
return (pwm_get_by_ofw_idx(consumer, node, idx, out_channel));
}