freebsd-dev/sys/dev/pwm/pwm_backlight.c

311 lines
8.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2020 Emmanuel Vadot <manu@FreeBSD.org>
*
* 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/endian.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/kernel.h>
#include <sys/kthread.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/priv.h>
#include <sys/slicer.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/extres/regulator/regulator.h>
#include <dev/backlight/backlight.h>
#include <dev/pwm/ofw_pwm.h>
#include "backlight_if.h"
#include "pwmbus_if.h"
struct pwm_backlight_softc {
device_t pwmdev;
struct cdev *cdev;
pwm_channel_t channel;
uint32_t *levels;
ssize_t nlevels;
int default_level;
ssize_t current_level;
regulator_t power_supply;
uint64_t period;
uint64_t duty;
bool enabled;
};
static int pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent);
static struct ofw_compat_data compat_data[] = {
{ "pwm-backlight", 1 },
{ NULL, 0 }
};
static int
pwm_backlight_probe(device_t dev)
{
if (!ofw_bus_search_compatible(dev, compat_data)->ocd_data)
return (ENXIO);
device_set_desc(dev, "PWM Backlight");
return (BUS_PROBE_DEFAULT);
}
static int
pwm_backlight_attach(device_t dev)
{
struct pwm_backlight_softc *sc;
phandle_t node;
int rv;
sc = device_get_softc(dev);
node = ofw_bus_get_node(dev);
rv = pwm_get_by_ofw_propidx(dev, node, "pwms", 0, &sc->channel);
if (rv != 0) {
device_printf(dev, "Cannot map pwm channel %d\n", rv);
return (ENXIO);
}
if (regulator_get_by_ofw_property(dev, 0, "power-supply",
&sc->power_supply) != 0) {
device_printf(dev, "No power-supply property\n");
return (ENXIO);
}
if (OF_hasprop(node, "brightness-levels")) {
sc->nlevels = OF_getencprop_alloc(node, "brightness-levels",
(void **)&sc->levels);
if (sc->nlevels <= 0) {
device_printf(dev, "Cannot parse brightness levels\n");
return (ENXIO);
}
sc->nlevels /= sizeof(uint32_t);
if (OF_getencprop(node, "default-brightness-level",
&sc->default_level, sizeof(uint32_t)) <= 0) {
device_printf(dev, "No default-brightness-level while brightness-levels is specified\n");
return (ENXIO);
} else {
if (sc->default_level > sc->nlevels) {
device_printf(dev, "default-brightness-level isn't present in brightness-levels range\n");
return (ENXIO);
}
sc->channel->duty = sc->channel->period * sc->levels[sc->default_level] / 100;
}
if (bootverbose) {
device_printf(dev, "Number of levels: %zd\n", sc->nlevels);
device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period);
device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty);
}
} else {
/* Get the current backlight level */
PWMBUS_CHANNEL_GET_CONFIG(sc->channel->dev,
sc->channel->channel,
(unsigned int *)&sc->channel->period,
(unsigned int *)&sc->channel->duty);
if (sc->channel->duty > sc->channel->period)
sc->channel->duty = sc->channel->period;
if (bootverbose) {
device_printf(dev, "Configured period time: %ju\n", (uintmax_t)sc->channel->period);
device_printf(dev, "Default duty cycle: %ju\n", (uintmax_t)sc->channel->duty);
}
}
regulator_enable(sc->power_supply);
sc->channel->enabled = true;
PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel,
sc->channel->period, sc->channel->duty);
PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel,
sc->channel->enabled);
sc->current_level = pwm_backlight_find_level_per_percent(sc,
sc->channel->period / sc->channel->duty);
sc->cdev = backlight_register("pwm_backlight", dev);
if (sc->cdev == NULL)
device_printf(dev, "Cannot register as a backlight\n");
return (0);
}
static int
pwm_backlight_detach(device_t dev)
{
struct pwm_backlight_softc *sc;
sc = device_get_softc(dev);
if (sc->nlevels > 0)
OF_prop_free(sc->levels);
regulator_disable(sc->power_supply);
backlight_destroy(sc->cdev);
return (0);
}
static int
pwm_backlight_find_level_per_percent(struct pwm_backlight_softc *sc, int percent)
{
int i;
int diff;
if (percent < 0 || percent > 100)
return (-1);
for (i = 0, diff = 0; i < sc->nlevels; i++) {
if (sc->levels[i] == percent)
return (i);
else if (sc->levels[i] < percent)
diff = percent - sc->levels[i];
else {
if (diff < abs((percent - sc->levels[i])))
return (i - 1);
else
return (i);
}
}
return (-1);
}
static int
pwm_backlight_update_status(device_t dev, struct backlight_props *props)
{
struct pwm_backlight_softc *sc;
int reg_status;
int error;
sc = device_get_softc(dev);
if (sc->nlevels != 0) {
error = pwm_backlight_find_level_per_percent(sc,
props->brightness);
if (error < 0)
return (ERANGE);
sc->current_level = error;
sc->channel->duty = sc->channel->period *
sc->levels[sc->current_level] / 100;
} else {
if (props->brightness > 100 || props->brightness < 0)
return (ERANGE);
sc->channel->duty = sc->channel->period *
props->brightness / 100;
}
sc->channel->enabled = true;
PWMBUS_CHANNEL_CONFIG(sc->channel->dev, sc->channel->channel,
sc->channel->period, sc->channel->duty);
PWMBUS_CHANNEL_ENABLE(sc->channel->dev, sc->channel->channel,
sc->channel->enabled);
error = regulator_status(sc->power_supply, &reg_status);
if (error != 0)
device_printf(dev,
"Cannot get power-supply status: %d\n", error);
else {
if (props->brightness > 0) {
if (reg_status != REGULATOR_STATUS_ENABLED)
regulator_enable(sc->power_supply);
} else {
if (reg_status == REGULATOR_STATUS_ENABLED)
regulator_disable(sc->power_supply);
}
}
return (0);
}
static int
pwm_backlight_get_status(device_t dev, struct backlight_props *props)
{
struct pwm_backlight_softc *sc;
int i;
sc = device_get_softc(dev);
if (sc->nlevels != 0) {
props->brightness = sc->levels[sc->current_level];
props->nlevels = sc->nlevels;
for (i = 0; i < sc->nlevels; i++)
props->levels[i] = sc->levels[i];
} else {
props->brightness = sc->channel->duty * 100 / sc->channel->period;
props->nlevels = 0;
}
return (0);
}
static int
pwm_backlight_get_info(device_t dev, struct backlight_info *info)
{
info->type = BACKLIGHT_TYPE_PANEL;
strlcpy(info->name, "pwm-backlight", BACKLIGHTMAXNAMELENGTH);
return (0);
}
static device_method_t pwm_backlight_methods[] = {
/* device_if */
DEVMETHOD(device_probe, pwm_backlight_probe),
DEVMETHOD(device_attach, pwm_backlight_attach),
DEVMETHOD(device_detach, pwm_backlight_detach),
/* backlight interface */
DEVMETHOD(backlight_update_status, pwm_backlight_update_status),
DEVMETHOD(backlight_get_status, pwm_backlight_get_status),
DEVMETHOD(backlight_get_info, pwm_backlight_get_info),
DEVMETHOD_END
};
driver_t pwm_backlight_driver = {
"pwm_backlight",
pwm_backlight_methods,
sizeof(struct pwm_backlight_softc),
};
DRIVER_MODULE(pwm_backlight, simplebus, pwm_backlight_driver, 0, 0);
MODULE_DEPEND(pwm_backlight, backlight, 1, 1, 1);
OFWBUS_PNP_INFO(compat_data);