freebsd-dev/sys/dev/pwm/pwmc.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

162 lines
4.0 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/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/time.h>
#include <sys/pwm.h>
#include "pwmbus_if.h"
#include "pwm_if.h"
struct pwmc_softc {
device_t dev;
device_t pdev;
struct cdev *pwm_dev;
char name[32];
};
static int
pwm_ioctl(struct cdev *dev, u_long cmd, caddr_t data,
int fflag, struct thread *td)
{
struct pwmc_softc *sc;
struct pwm_state state;
device_t bus;
int nchannel;
int rv = 0;
sc = dev->si_drv1;
bus = PWM_GET_BUS(sc->pdev);
if (bus == NULL)
return (EINVAL);
switch (cmd) {
case PWMMAXCHANNEL:
nchannel = -1;
rv = PWM_CHANNEL_MAX(sc->pdev, &nchannel);
bcopy(&nchannel, data, sizeof(nchannel));
break;
case PWMSETSTATE:
bcopy(data, &state, sizeof(state));
rv = PWMBUS_CHANNEL_CONFIG(bus, state.channel,
state.period, state.duty);
if (rv == 0)
rv = PWMBUS_CHANNEL_ENABLE(bus, state.channel,
state.enable);
break;
case PWMGETSTATE:
bcopy(data, &state, sizeof(state));
rv = PWMBUS_CHANNEL_GET_CONFIG(bus, state.channel,
&state.period, &state.duty);
if (rv != 0)
return (rv);
rv = PWMBUS_CHANNEL_IS_ENABLED(bus, state.channel,
&state.enable);
if (rv != 0)
return (rv);
bcopy(&state, data, sizeof(state));
break;
}
return (rv);
}
static struct cdevsw pwm_cdevsw = {
.d_version = D_VERSION,
.d_name = "pwm",
.d_ioctl = pwm_ioctl
};
static int
pwmc_probe(device_t dev)
{
device_set_desc(dev, "PWM Controller");
return (0);
}
static int
pwmc_attach(device_t dev)
{
struct pwmc_softc *sc;
struct make_dev_args args;
sc = device_get_softc(dev);
sc->dev = dev;
sc->pdev = device_get_parent(dev);
snprintf(sc->name, sizeof(sc->name), "pwmc%d", device_get_unit(dev));
make_dev_args_init(&args);
args.mda_flags = MAKEDEV_CHECKNAME | MAKEDEV_WAITOK;
args.mda_devsw = &pwm_cdevsw;
args.mda_uid = UID_ROOT;
args.mda_gid = GID_OPERATOR;
args.mda_mode = 0600;
args.mda_si_drv1 = sc;
if (make_dev_s(&args, &sc->pwm_dev, "%s", sc->name) != 0) {
device_printf(dev, "Failed to make PWM device\n");
return (ENXIO);
}
return (0);
}
static int
pwmc_detach(device_t dev)
{
return (0);
}
static device_method_t pwmc_methods[] = {
/* device_if */
DEVMETHOD(device_probe, pwmc_probe),
DEVMETHOD(device_attach, pwmc_attach),
DEVMETHOD(device_detach, pwmc_detach),
DEVMETHOD_END
};
driver_t pwmc_driver = {
"pwmc",
pwmc_methods,
sizeof(struct pwmc_softc),
};
devclass_t pwmc_devclass;
DRIVER_MODULE(pwmc, pwm, pwmc_driver, pwmc_devclass, 0, 0);
MODULE_VERSION(pwmc, 1);