freebsd-dev/sys/dev/gpio/gpioregulator.c
Jared McNeill 72f1cf0446 Add driver for GPIO controlled regulator.
Reviewed by:		gonzo, manu, mmel
Differential Revision:	https://reviews.freebsd.org/D8257
2016-10-15 20:04:14 +00:00

349 lines
8.5 KiB
C

/*-
* Copyright (c) 2016 Jared McNeill <jmcneill@invisible.ca>
* 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 ``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 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.
*
* $FreeBSD$
*/
/*
* GPIO controlled regulators
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/gpio.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/gpio/gpiobusvar.h>
#include <dev/extres/regulator/regulator.h>
#include "regdev_if.h"
struct gpioregulator_state {
int val;
uint32_t mask;
};
struct gpioregulator_init_def {
struct regnode_init_def reg_init_def;
struct gpiobus_pin *enable_pin;
int enable_pin_valid;
int startup_delay_us;
int nstates;
struct gpioregulator_state *states;
int npins;
struct gpiobus_pin **pins;
};
struct gpioregulator_reg_sc {
struct regnode *regnode;
device_t base_dev;
struct regnode_std_param *param;
struct gpioregulator_init_def *def;
};
struct gpioregulator_softc {
device_t dev;
struct gpioregulator_reg_sc *reg_sc;
struct gpioregulator_init_def init_def;
};
static int
gpioregulator_regnode_init(struct regnode *regnode)
{
struct gpioregulator_reg_sc *sc;
int error, n;
sc = regnode_get_softc(regnode);
if (sc->def->enable_pin_valid == 1) {
error = gpio_pin_setflags(sc->def->enable_pin, GPIO_PIN_OUTPUT);
if (error != 0)
return (error);
}
for (n = 0; n < sc->def->npins; n++) {
error = gpio_pin_setflags(sc->def->pins[n], GPIO_PIN_OUTPUT);
if (error != 0)
return (error);
}
return (0);
}
static int
gpioregulator_regnode_enable(struct regnode *regnode, bool enable, int *udelay)
{
struct gpioregulator_reg_sc *sc;
bool active;
int error;
sc = regnode_get_softc(regnode);
if (sc->def->enable_pin_valid == 1) {
active = enable;
if (!sc->param->enable_active_high)
active = !active;
error = gpio_pin_set_active(sc->def->enable_pin, active);
if (error != 0)
return (error);
}
*udelay = sc->def->startup_delay_us;
return (0);
}
static int
gpioregulator_regnode_set_voltage(struct regnode *regnode, int min_uvolt,
int max_uvolt, int *udelay)
{
struct gpioregulator_reg_sc *sc;
const struct gpioregulator_state *state;
int error, n;
sc = regnode_get_softc(regnode);
state = NULL;
for (n = 0; n < sc->def->nstates; n++) {
if (sc->def->states[n].val >= min_uvolt &&
sc->def->states[n].val <= max_uvolt) {
state = &sc->def->states[n];
break;
}
}
if (state == NULL)
return (EINVAL);
for (n = 0; n < sc->def->npins; n++) {
error = gpio_pin_set_active(sc->def->pins[n],
(state->mask >> n) & 1);
if (error != 0)
return (error);
}
*udelay = sc->def->startup_delay_us;
return (0);
}
static int
gpioregulator_regnode_get_voltage(struct regnode *regnode, int *uvolt)
{
struct gpioregulator_reg_sc *sc;
uint32_t mask;
int error, n;
bool active;
sc = regnode_get_softc(regnode);
mask = 0;
for (n = 0; n < sc->def->npins; n++) {
error = gpio_pin_is_active(sc->def->pins[n], &active);
if (error != 0)
return (error);
mask |= (active << n);
}
for (n = 0; n < sc->def->nstates; n++) {
if (sc->def->states[n].mask == mask) {
*uvolt = sc->def->states[n].val;
return (0);
}
}
return (EIO);
}
static regnode_method_t gpioregulator_regnode_methods[] = {
/* Regulator interface */
REGNODEMETHOD(regnode_init, gpioregulator_regnode_init),
REGNODEMETHOD(regnode_enable, gpioregulator_regnode_enable),
REGNODEMETHOD(regnode_set_voltage, gpioregulator_regnode_set_voltage),
REGNODEMETHOD(regnode_get_voltage, gpioregulator_regnode_get_voltage),
REGNODEMETHOD_END
};
DEFINE_CLASS_1(gpioregulator_regnode, gpioregulator_regnode_class,
gpioregulator_regnode_methods, sizeof(struct gpioregulator_reg_sc),
regnode_class);
static int
gpioregulator_parse_fdt(struct gpioregulator_softc *sc)
{
uint32_t *pstates, mask;
phandle_t node;
ssize_t len;
int error, n;
node = ofw_bus_get_node(sc->dev);
pstates = NULL;
mask = 0;
error = regulator_parse_ofw_stdparam(sc->dev, node,
&sc->init_def.reg_init_def);
if (error != 0)
return (error);
/* "states" property (required) */
len = OF_getencprop_alloc(node, "states", sizeof(*pstates),
(void **)&pstates);
if (len < 2) {
device_printf(sc->dev, "invalid 'states' property\n");
error = EINVAL;
goto done;
}
sc->init_def.nstates = len / 2;
sc->init_def.states = malloc(sc->init_def.nstates *
sizeof(*sc->init_def.states), M_DEVBUF, M_WAITOK);
for (n = 0; n < sc->init_def.nstates; n++) {
sc->init_def.states[n].val = pstates[n * 2 + 0];
sc->init_def.states[n].mask = pstates[n * 2 + 1];
mask |= sc->init_def.states[n].mask;
}
/* "startup-delay-us" property (optional) */
len = OF_getencprop(node, "startup-delay-us",
&sc->init_def.startup_delay_us,
sizeof(sc->init_def.startup_delay_us));
if (len <= 0)
sc->init_def.startup_delay_us = 0;
/* "enable-gpio" property (optional) */
error = gpio_pin_get_by_ofw_property(sc->dev, node, "enable-gpio",
&sc->init_def.enable_pin);
if (error == 0)
sc->init_def.enable_pin_valid = 1;
/* "gpios" property */
sc->init_def.npins = 32 - __builtin_clz(mask);
sc->init_def.pins = malloc(sc->init_def.npins *
sizeof(sc->init_def.pins), M_DEVBUF, M_WAITOK);
for (n = 0; n < sc->init_def.npins; n++) {
error = gpio_pin_get_by_ofw_idx(sc->dev, node, n,
&sc->init_def.pins[n]);
if (error != 0) {
device_printf(sc->dev, "cannot get pin %d\n", n);
goto done;
}
}
done:
if (error != 0) {
for (n = 0; n < sc->init_def.npins; n++) {
if (sc->init_def.pins[n] != NULL)
gpio_pin_release(sc->init_def.pins[n]);
}
free(sc->init_def.states, M_DEVBUF);
free(sc->init_def.pins, M_DEVBUF);
}
OF_prop_free(pstates);
return (error);
}
static int
gpioregulator_probe(device_t dev)
{
if (!ofw_bus_is_compatible(dev, "regulator-gpio"))
return (ENXIO);
device_set_desc(dev, "GPIO controlled regulator");
return (BUS_PROBE_GENERIC);
}
static int
gpioregulator_attach(device_t dev)
{
struct gpioregulator_softc *sc;
struct regnode *regnode;
phandle_t node;
int error;
sc = device_get_softc(dev);
sc->dev = dev;
node = ofw_bus_get_node(dev);
error = gpioregulator_parse_fdt(sc);
if (error != 0) {
device_printf(dev, "cannot parse parameters\n");
return (ENXIO);
}
sc->init_def.reg_init_def.id = 1;
sc->init_def.reg_init_def.ofw_node = node;
regnode = regnode_create(dev, &gpioregulator_regnode_class,
&sc->init_def.reg_init_def);
if (regnode == NULL) {
device_printf(dev, "cannot create regulator\n");
return (ENXIO);
}
sc->reg_sc = regnode_get_softc(regnode);
sc->reg_sc->regnode = regnode;
sc->reg_sc->base_dev = dev;
sc->reg_sc->param = regnode_get_stdparam(regnode);
sc->reg_sc->def = &sc->init_def;
regnode_register(regnode);
return (0);
}
static device_method_t gpioregulator_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, gpioregulator_probe),
DEVMETHOD(device_attach, gpioregulator_attach),
/* Regdev interface */
DEVMETHOD(regdev_map, regdev_default_ofw_map),
DEVMETHOD_END
};
static driver_t gpioregulator_driver = {
"gpioregulator",
gpioregulator_methods,
sizeof(struct gpioregulator_softc),
};
static devclass_t gpioregulator_devclass;
EARLY_DRIVER_MODULE(gpioregulator, simplebus, gpioregulator_driver,
gpioregulator_devclass, 0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LAST);
MODULE_VERSION(gpioregulator, 1);