freebsd-skq/sys/dev/gpio/gpiomdio.c
Luiz Otavio O Souza fdfcae4a2f Add a GPIO based MDIO bit-banging bus driver.
Uses two GPIO pins as MDC (clock) and MDIO (bidirectional I/O), relies
on mii_bitbang.

Tested on SG-3200 where the PHY for one of the ports is wired independently
of the SoC MDIO bus.

Sponsored by:	Rubicon Communications, LLC (Netgate)
2019-12-06 20:21:07 +00:00

244 lines
6.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2019 Rubicon Communications, LLC (Netgate)
*
* 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>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <dev/fdt/fdt_common.h>
#include <dev/gpio/gpiobusvar.h>
#include <dev/mii/mii_bitbang.h>
#include <dev/mii/miivar.h>
#include <dev/ofw/ofw_bus.h>
#include "gpiobus_if.h"
#include "miibus_if.h"
#define GPIOMDIO_MDC_DFLT 0
#define GPIOMDIO_MDIO_DFLT 1
#define GPIOMDIO_MIN_PINS 2
#define MDO_BIT 0x01
#define MDI_BIT 0x02
#define MDC_BIT 0x04
#define MDIRPHY_BIT 0x08
#define MDIRHOST_BIT 0x10
#define MDO sc->miibb_ops.mbo_bits[MII_BIT_MDO]
#define MDI sc->miibb_ops.mbo_bits[MII_BIT_MDI]
#define MDC sc->miibb_ops.mbo_bits[MII_BIT_MDC]
#define MDIRPHY sc->miibb_ops.mbo_bits[MII_BIT_DIR_HOST_PHY]
#define MDIRHOST sc->miibb_ops.mbo_bits[MII_BIT_DIR_PHY_HOST]
static uint32_t gpiomdio_bb_read(device_t);
static void gpiomdio_bb_write(device_t, uint32_t);
struct gpiomdio_softc
{
device_t sc_dev;
device_t sc_busdev;
int mdc_pin;
int mdio_pin;
struct mii_bitbang_ops miibb_ops;
};
static int
gpiomdio_probe(device_t dev)
{
struct gpiobus_ivar *devi;
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "freebsd,gpiomdio"))
return (ENXIO);
devi = GPIOBUS_IVAR(dev);
if (devi->npins < GPIOMDIO_MIN_PINS) {
device_printf(dev,
"gpiomdio needs at least %d GPIO pins (only %d given).\n",
GPIOMDIO_MIN_PINS, devi->npins);
return (ENXIO);
}
device_set_desc(dev, "GPIO MDIO bit-banging Bus driver");
return (BUS_PROBE_DEFAULT);
}
static int
gpiomdio_attach(device_t dev)
{
phandle_t node;
pcell_t pin;
struct gpiobus_ivar *devi;
struct gpiomdio_softc *sc;
sc = device_get_softc(dev);
sc->sc_dev = dev;
sc->sc_busdev = device_get_parent(dev);
if ((node = ofw_bus_get_node(dev)) == -1)
return (ENXIO);
if (OF_getencprop(node, "mdc", &pin, sizeof(pin)) > 0)
sc->mdc_pin = (int)pin;
if (OF_getencprop(node, "mdio", &pin, sizeof(pin)) > 0)
sc->mdio_pin = (int)pin;
if (sc->mdc_pin < 0 || sc->mdc_pin > 1)
sc->mdc_pin = GPIOMDIO_MDC_DFLT;
if (sc->mdio_pin < 0 || sc->mdio_pin > 1)
sc->mdio_pin = GPIOMDIO_MDIO_DFLT;
devi = GPIOBUS_IVAR(dev);
device_printf(dev, "MDC pin: %d, MDIO pin: %d\n",
devi->pins[sc->mdc_pin], devi->pins[sc->mdio_pin]);
/* Initialize mii_bitbang_ops. */
MDO = MDO_BIT;
MDI = MDI_BIT;
MDC = MDC_BIT;
MDIRPHY = MDIRPHY_BIT;
MDIRHOST = MDIRHOST_BIT;
sc->miibb_ops.mbo_read = gpiomdio_bb_read;
sc->miibb_ops.mbo_write = gpiomdio_bb_write;
/* Register our MDIO Bus device. */
OF_device_register_xref(OF_xref_from_node(node), dev);
return (0);
}
static uint32_t
gpiomdio_bb_read(device_t dev)
{
struct gpiomdio_softc *sc;
unsigned int val;
sc = device_get_softc(dev);
GPIOBUS_PIN_GET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, &val);
return (val != 0 ? MDI_BIT : 0);
}
static void
gpiomdio_bb_write(device_t dev, uint32_t val)
{
struct gpiomdio_softc *sc;
sc = device_get_softc(dev);
/* Set the data pin state. */
if ((val & (MDIRPHY_BIT | MDO_BIT)) == (MDIRPHY_BIT | MDO_BIT))
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, 1);
else if ((val & (MDIRPHY_BIT | MDO_BIT)) == MDIRPHY_BIT)
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdio_pin, 0);
if (val & MDIRPHY_BIT)
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdio_pin,
GPIO_PIN_OUTPUT);
else if (val & MDIRHOST_BIT)
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdio_pin,
GPIO_PIN_INPUT);
/* And now the clock state. */
if (val & MDC_BIT)
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdc_pin, 1);
else
GPIOBUS_PIN_SET(sc->sc_busdev, sc->sc_dev, sc->mdc_pin, 0);
GPIOBUS_PIN_SETFLAGS(sc->sc_busdev, sc->sc_dev, sc->mdc_pin,
GPIO_PIN_OUTPUT);
}
static int
gpiomdio_readreg(device_t dev, int phy, int reg)
{
struct gpiomdio_softc *sc;
sc = device_get_softc(dev);
return (mii_bitbang_readreg(dev, &sc->miibb_ops, phy, reg));
}
static int
gpiomdio_writereg(device_t dev, int phy, int reg, int val)
{
struct gpiomdio_softc *sc;
sc = device_get_softc(dev);
mii_bitbang_writereg(dev, &sc->miibb_ops, phy, reg, val);
return (0);
}
static phandle_t
gpiomdio_get_node(device_t bus, device_t dev)
{
return (ofw_bus_get_node(bus));
}
static devclass_t gpiomdio_devclass;
static device_method_t gpiomdio_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, gpiomdio_probe),
DEVMETHOD(device_attach, gpiomdio_attach),
DEVMETHOD(device_detach, bus_generic_detach),
/* MDIO interface */
DEVMETHOD(miibus_readreg, gpiomdio_readreg),
DEVMETHOD(miibus_writereg, gpiomdio_writereg),
/* OFW bus interface */
DEVMETHOD(ofw_bus_get_node, gpiomdio_get_node),
DEVMETHOD_END
};
static driver_t gpiomdio_driver = {
"gpiomdio",
gpiomdio_methods,
sizeof(struct gpiomdio_softc),
};
EARLY_DRIVER_MODULE(gpiomdio, gpiobus, gpiomdio_driver, gpiomdio_devclass,
0, 0, BUS_PASS_BUS + BUS_PASS_ORDER_MIDDLE);
DRIVER_MODULE(miibus, gpiomdio, miibus_driver, miibus_devclass, 0, 0);
MODULE_DEPEND(gpiomdio, gpiobus, 1, 1, 1);
MODULE_DEPEND(gpiomdio, miibus, 1, 1, 1);
MODULE_DEPEND(gpiomdio, mii_bitbang, 1, 1, 1);