freebsd-dev/sys/dev/gpio/gpioiic.c
Pedro F. Giffuni 718cf2ccb9 sys/dev: further adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.
2017-11-27 14:52:40 +00:00

271 lines
7.0 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009 Oleksandr Tymoshenko <gonzo@freebsd.org>
* Copyright (c) 2010 Luiz Otavio O Souza
* 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 "opt_platform.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/gpio.h>
#include <sys/kernel.h>
#include <sys/module.h>
#ifdef FDT
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#endif
#include <dev/gpio/gpiobusvar.h>
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "gpiobus_if.h"
#include "iicbb_if.h"
#define GPIOIIC_SCL_DFLT 0
#define GPIOIIC_SDA_DFLT 1
#define GPIOIIC_MIN_PINS 2
struct gpioiic_softc
{
device_t sc_dev;
device_t sc_busdev;
int scl_pin;
int sda_pin;
};
static int gpioiic_probe(device_t);
static int gpioiic_attach(device_t);
/* iicbb interface */
static void gpioiic_reset_bus(device_t);
static void gpioiic_setsda(device_t, int);
static void gpioiic_setscl(device_t, int);
static int gpioiic_getsda(device_t);
static int gpioiic_getscl(device_t);
static int gpioiic_reset(device_t, u_char, u_char, u_char *);
static int
gpioiic_probe(device_t dev)
{
struct gpiobus_ivar *devi;
#ifdef FDT
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "gpioiic"))
return (ENXIO);
#endif
devi = GPIOBUS_IVAR(dev);
if (devi->npins < GPIOIIC_MIN_PINS) {
device_printf(dev,
"gpioiic needs at least %d GPIO pins (only %d given).\n",
GPIOIIC_MIN_PINS, devi->npins);
return (ENXIO);
}
device_set_desc(dev, "GPIO I2C bit-banging driver");
return (BUS_PROBE_DEFAULT);
}
static int
gpioiic_attach(device_t dev)
{
device_t bitbang;
#ifdef FDT
phandle_t node;
pcell_t pin;
#endif
struct gpiobus_ivar *devi;
struct gpioiic_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_busdev = device_get_parent(dev);
if (resource_int_value(device_get_name(dev),
device_get_unit(dev), "scl", &sc->scl_pin))
sc->scl_pin = GPIOIIC_SCL_DFLT;
if (resource_int_value(device_get_name(dev),
device_get_unit(dev), "sda", &sc->sda_pin))
sc->sda_pin = GPIOIIC_SDA_DFLT;
#ifdef FDT
if ((node = ofw_bus_get_node(dev)) == -1)
return (ENXIO);
if (OF_getencprop(node, "scl", &pin, sizeof(pin)) > 0)
sc->scl_pin = (int)pin;
if (OF_getencprop(node, "sda", &pin, sizeof(pin)) > 0)
sc->sda_pin = (int)pin;
#endif
if (sc->scl_pin < 0 || sc->scl_pin > 1)
sc->scl_pin = GPIOIIC_SCL_DFLT;
if (sc->sda_pin < 0 || sc->sda_pin > 1)
sc->sda_pin = GPIOIIC_SDA_DFLT;
devi = GPIOBUS_IVAR(dev);
device_printf(dev, "SCL pin: %d, SDA pin: %d\n",
devi->pins[sc->scl_pin], devi->pins[sc->sda_pin]);
/* add generic bit-banging code */
bitbang = device_add_child(dev, "iicbb", -1);
device_probe_and_attach(bitbang);
return (0);
}
/*
* Reset bus by setting SDA first and then SCL.
* Must always be called with gpio bus locked.
*/
static void
gpioiic_reset_bus(device_t dev)
{
struct gpioiic_softc *sc = device_get_softc(dev);
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
GPIO_PIN_INPUT);
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
GPIO_PIN_INPUT);
}
static void
gpioiic_setsda(device_t dev, int val)
{
struct gpioiic_softc *sc = device_get_softc(dev);
if (val == 0) {
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, 0);
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
GPIO_PIN_OUTPUT);
} else {
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
GPIO_PIN_INPUT);
}
}
static void
gpioiic_setscl(device_t dev, int val)
{
struct gpioiic_softc *sc = device_get_softc(dev);
if (val == 0) {
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, 0);
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
GPIO_PIN_OUTPUT);
} else {
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
GPIO_PIN_INPUT);
}
}
static int
gpioiic_getscl(device_t dev)
{
struct gpioiic_softc *sc = device_get_softc(dev);
unsigned int val;
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->scl_pin,
GPIO_PIN_INPUT);
GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->scl_pin, &val);
return ((int)val);
}
static int
gpioiic_getsda(device_t dev)
{
struct gpioiic_softc *sc = device_get_softc(dev);
unsigned int val;
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->sda_pin,
GPIO_PIN_INPUT);
GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->sda_pin, &val);
return ((int)val);
}
static int
gpioiic_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr)
{
struct gpioiic_softc *sc;
sc = device_get_softc(dev);
gpioiic_reset_bus(sc->sc_dev);
return (IIC_ENOADDR);
}
#ifdef FDT
static phandle_t
gpioiic_get_node(device_t bus, device_t dev)
{
/* We only have one child, the iicbb, which needs our own node. */
return (ofw_bus_get_node(bus));
}
#endif
static devclass_t gpioiic_devclass;
static device_method_t gpioiic_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, gpioiic_probe),
DEVMETHOD(device_attach, gpioiic_attach),
DEVMETHOD(device_detach, bus_generic_detach),
/* iicbb interface */
DEVMETHOD(iicbb_setsda, gpioiic_setsda),
DEVMETHOD(iicbb_setscl, gpioiic_setscl),
DEVMETHOD(iicbb_getsda, gpioiic_getsda),
DEVMETHOD(iicbb_getscl, gpioiic_getscl),
DEVMETHOD(iicbb_reset, gpioiic_reset),
#ifdef FDT
/* OFW bus interface */
DEVMETHOD(ofw_bus_get_node, gpioiic_get_node),
#endif
DEVMETHOD_END
};
static driver_t gpioiic_driver = {
"gpioiic",
gpioiic_methods,
sizeof(struct gpioiic_softc),
};
DRIVER_MODULE(gpioiic, gpiobus, gpioiic_driver, gpioiic_devclass, 0, 0);
DRIVER_MODULE(iicbb, gpioiic, iicbb_driver, iicbb_devclass, 0, 0);
MODULE_DEPEND(gpioiic, iicbb, IICBB_MINVER, IICBB_PREFVER, IICBB_MAXVER);
MODULE_DEPEND(gpioiic, gpiobus, 1, 1, 1);