freebsd-skq/sys/dev/gpio/gpioiic.c
Luiz Otavio O Souza 9a2a079a51 Add OFW support to the in tree gpio compatible devices: gpioiic(4) and
gpioled(4).

Tested on RPi and BBB (using the hardware I2C controller and gpioiic(4) for
the I2C tests).  It was also verified for regressions on RSPRO (MIPS/ar71xx)
used as reference for a non OFW-based system.

Update the gpioled(4) and gpioiic(4) man pages with some details and
examples about the FDT/OFW support.

Some compatibility details pointed out by imp@ will follow in subsequent
commits.

Approved by:	adrian (mentor, implicit)
2014-02-13 17:58:52 +00:00

281 lines
7.1 KiB
C

/*-
* 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/conf.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/gpio.h>
#include "gpiobus_if.h"
#ifdef FDT
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/fdt/fdt_common.h>
#endif
#include <dev/iicbus/iiconf.h>
#include <dev/iicbus/iicbus.h>
#include "iicbb_if.h"
#define SCL_PIN_DEFAULT 0 /* default index of SCL pin on gpiobus */
#define SDA_PIN_DEFAULT 1
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 int gpioiic_callback(device_t, int, caddr_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)
{
#ifdef FDT
if (!ofw_bus_is_compatible(dev, "gpioiic"))
return (ENXIO);
#endif
device_set_desc(dev, "GPIO I2C bit-banging driver");
return (0);
}
static int
gpioiic_attach(device_t dev)
{
struct gpioiic_softc *sc = device_get_softc(dev);
device_t bitbang;
#ifdef FDT
phandle_t node;
pcell_t pin;
#endif
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 = SCL_PIN_DEFAULT;
if (resource_int_value(device_get_name(dev),
device_get_unit(dev), "sda", &sc->sda_pin))
sc->sda_pin = SDA_PIN_DEFAULT;
#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
/* 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 int
gpioiic_callback(device_t dev, int index, caddr_t data)
{
struct gpioiic_softc *sc = device_get_softc(dev);
int error = 0;
switch (index) {
case IIC_REQUEST_BUS:
GPIOBUS_LOCK_BUS(sc->sc_busdev);
GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev);
GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
break;
case IIC_RELEASE_BUS:
GPIOBUS_LOCK_BUS(sc->sc_busdev);
GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev);
GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
break;
default:
error = EINVAL;
}
return (error);
}
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 = device_get_softc(dev);
GPIOBUS_LOCK_BUS(sc->sc_busdev);
GPIOBUS_ACQUIRE_BUS(sc->sc_busdev, sc->sc_dev);
gpioiic_reset_bus(sc->sc_dev);
GPIOBUS_RELEASE_BUS(sc->sc_busdev, sc->sc_dev);
GPIOBUS_UNLOCK_BUS(sc->sc_busdev);
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_callback, gpioiic_callback),
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
{ 0, 0 }
};
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);