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freebsd/sys/arm/xilinx/zy7_gpio.c
Oleksandr Tymoshenko 8857481840 Fix accidental USB port resets by GPIO on Zynq/Zedboard boards
The Zynq/Zedboard GPIO driver attempts to tri-state all GPIO pins on
boot up but the order in which I reset the hardware can cause the pins
to be briefly held low before being tri-stated.  This is a problem on
boards that use GPIO pins to reset devices.

In particular, the Zybo and ZC-706 boards use a GPIO pin as a USB PHY
reset.  If U-boot enables the USB port before booting the kernel, the
GPIO driver attach causes a glitch on the USB PHY reset and the USB
port loses power.  My fix is to have the GPIO driver leave the pins in
whatever configuration U-boot placed them.

PR:		225713
Submitted by:	Thomas Skibo <thoma555-bsd@yahoo.com>
MFC after:	1 week
2018-04-03 04:31:54 +00:00

379 lines
9.7 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2013 Thomas Skibo
* 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.
*
* $FreeBSD$
*/
/*
* A GPIO driver for Xilinx Zynq-7000.
*
* The GPIO peripheral on Zynq allows controlling 114 general purpose I/Os.
*
* Pins 53-0 are sent to the MIO. Any MIO pins not used by a PS peripheral are
* available as a GPIO pin. Pins 64-127 are sent to the PL (FPGA) section of
* Zynq as EMIO signals.
*
* The hardware provides a way to use IOs as interrupt sources but the
* gpio framework doesn't seem to have hooks for this.
*
* Reference: Zynq-7000 All Programmable SoC Technical Reference Manual.
* (v1.4) November 16, 2012. Xilinx doc UG585. GPIO is covered in
* chater 14. Register definitions are in appendix B.19.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/gpio.h>
#include <machine/bus.h>
#include <machine/resource.h>
#include <machine/stdarg.h>
#include <dev/gpio/gpiobusvar.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include "gpio_if.h"
#define NUMBANKS 4
#define MAXPIN (32*NUMBANKS)
#define MIO_PIN 0 /* pins 0-53 go to MIO */
#define NUM_MIO_PINS 54
#define EMIO_PIN 64 /* pins 64-127 go to PL */
#define NUM_EMIO_PINS 64
#define VALID_PIN(u) (((u) >= MIO_PIN && (u) < MIO_PIN + NUM_MIO_PINS) || \
((u) >= EMIO_PIN && (u) < EMIO_PIN + NUM_EMIO_PINS))
#define ZGPIO_LOCK(sc) mtx_lock(&(sc)->sc_mtx)
#define ZGPIO_UNLOCK(sc) mtx_unlock(&(sc)->sc_mtx)
#define ZGPIO_LOCK_INIT(sc) \
mtx_init(&(sc)->sc_mtx, device_get_nameunit((sc)->dev), \
"gpio", MTX_DEF)
#define ZGPIO_LOCK_DESTROY(_sc) mtx_destroy(&_sc->sc_mtx);
struct zy7_gpio_softc {
device_t dev;
device_t busdev;
struct mtx sc_mtx;
struct resource *mem_res; /* Memory resource */
};
#define WR4(sc, off, val) bus_write_4((sc)->mem_res, (off), (val))
#define RD4(sc, off) bus_read_4((sc)->mem_res, (off))
/* Xilinx Zynq-7000 GPIO register definitions:
*/
#define ZY7_GPIO_MASK_DATA_LSW(b) (0x0000+8*(b)) /* maskable wr lo */
#define ZY7_GPIO_MASK_DATA_MSW(b) (0x0004+8*(b)) /* maskable wr hi */
#define ZY7_GPIO_DATA(b) (0x0040+4*(b)) /* in/out data */
#define ZY7_GPIO_DATA_RO(b) (0x0060+4*(b)) /* input data */
#define ZY7_GPIO_DIRM(b) (0x0204+0x40*(b)) /* direction mode */
#define ZY7_GPIO_OEN(b) (0x0208+0x40*(b)) /* output enable */
#define ZY7_GPIO_INT_MASK(b) (0x020c+0x40*(b)) /* int mask */
#define ZY7_GPIO_INT_EN(b) (0x0210+0x40*(b)) /* int enable */
#define ZY7_GPIO_INT_DIS(b) (0x0214+0x40*(b)) /* int disable */
#define ZY7_GPIO_INT_STAT(b) (0x0218+0x40*(b)) /* int status */
#define ZY7_GPIO_INT_TYPE(b) (0x021c+0x40*(b)) /* int type */
#define ZY7_GPIO_INT_POLARITY(b) (0x0220+0x40*(b)) /* int polarity */
#define ZY7_GPIO_INT_ANY(b) (0x0224+0x40*(b)) /* any edge */
static device_t
zy7_gpio_get_bus(device_t dev)
{
struct zy7_gpio_softc *sc;
sc = device_get_softc(dev);
return (sc->busdev);
}
static int
zy7_gpio_pin_max(device_t dev, int *maxpin)
{
*maxpin = MAXPIN;
return (0);
}
/* Get a specific pin's capabilities. */
static int
zy7_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
if (!VALID_PIN(pin))
return (EINVAL);
*caps = (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
return (0);
}
/* Get a specific pin's name. */
static int
zy7_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{
if (!VALID_PIN(pin))
return (EINVAL);
if (pin < NUM_MIO_PINS) {
snprintf(name, GPIOMAXNAME, "MIO_%d", pin);
name[GPIOMAXNAME - 1] = '\0';
} else {
snprintf(name, GPIOMAXNAME, "EMIO_%d", pin - EMIO_PIN);
name[GPIOMAXNAME - 1] = '\0';
}
return (0);
}
/* Get a specific pin's current in/out/tri state. */
static int
zy7_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
if (!VALID_PIN(pin))
return (EINVAL);
ZGPIO_LOCK(sc);
if ((RD4(sc, ZY7_GPIO_DIRM(pin >> 5)) & (1 << (pin & 31))) != 0) {
/* output */
if ((RD4(sc, ZY7_GPIO_OEN(pin >> 5)) & (1 << (pin & 31))) == 0)
*flags = (GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE);
else
*flags = GPIO_PIN_OUTPUT;
} else
/* input */
*flags = GPIO_PIN_INPUT;
ZGPIO_UNLOCK(sc);
return (0);
}
/* Set a specific pin's in/out/tri state. */
static int
zy7_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
if (!VALID_PIN(pin))
return (EINVAL);
ZGPIO_LOCK(sc);
if ((flags & GPIO_PIN_OUTPUT) != 0) {
/* Output. Set or reset OEN too. */
WR4(sc, ZY7_GPIO_DIRM(pin >> 5),
RD4(sc, ZY7_GPIO_DIRM(pin >> 5)) | (1 << (pin & 31)));
if ((flags & GPIO_PIN_TRISTATE) != 0)
WR4(sc, ZY7_GPIO_OEN(pin >> 5),
RD4(sc, ZY7_GPIO_OEN(pin >> 5)) &
~(1 << (pin & 31)));
else
WR4(sc, ZY7_GPIO_OEN(pin >> 5),
RD4(sc, ZY7_GPIO_OEN(pin >> 5)) |
(1 << (pin & 31)));
} else {
/* Input. Turn off OEN. */
WR4(sc, ZY7_GPIO_DIRM(pin >> 5),
RD4(sc, ZY7_GPIO_DIRM(pin >> 5)) & ~(1 << (pin & 31)));
WR4(sc, ZY7_GPIO_OEN(pin >> 5),
RD4(sc, ZY7_GPIO_OEN(pin >> 5)) & ~(1 << (pin & 31)));
}
ZGPIO_UNLOCK(sc);
return (0);
}
/* Set a specific output pin's value. */
static int
zy7_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
if (!VALID_PIN(pin) || value > 1)
return (EINVAL);
/* Fancy register tricks allow atomic set or reset. */
if ((pin & 16) != 0)
WR4(sc, ZY7_GPIO_MASK_DATA_MSW(pin >> 5),
(0xffff0000 ^ (0x10000 << (pin & 15))) |
(value << (pin & 15)));
else
WR4(sc, ZY7_GPIO_MASK_DATA_LSW(pin >> 5),
(0xffff0000 ^ (0x10000 << (pin & 15))) |
(value << (pin & 15)));
return (0);
}
/* Get a specific pin's input value. */
static int
zy7_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *value)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
if (!VALID_PIN(pin))
return (EINVAL);
*value = (RD4(sc, ZY7_GPIO_DATA_RO(pin >> 5)) >> (pin & 31)) & 1;
return (0);
}
/* Toggle a pin's output value. */
static int
zy7_gpio_pin_toggle(device_t dev, uint32_t pin)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
if (!VALID_PIN(pin))
return (EINVAL);
ZGPIO_LOCK(sc);
WR4(sc, ZY7_GPIO_DATA(pin >> 5),
RD4(sc, ZY7_GPIO_DATA(pin >> 5)) ^ (1 << (pin & 31)));
ZGPIO_UNLOCK(sc);
return (0);
}
static int
zy7_gpio_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (!ofw_bus_is_compatible(dev, "xlnx,zy7_gpio"))
return (ENXIO);
device_set_desc(dev, "Zynq-7000 GPIO driver");
return (0);
}
static int zy7_gpio_detach(device_t dev);
static int
zy7_gpio_attach(device_t dev)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
int rid;
sc->dev = dev;
ZGPIO_LOCK_INIT(sc);
/* Allocate memory. */
rid = 0;
sc->mem_res = bus_alloc_resource_any(dev,
SYS_RES_MEMORY, &rid, RF_ACTIVE);
if (sc->mem_res == NULL) {
device_printf(dev, "Can't allocate memory for device");
zy7_gpio_detach(dev);
return (ENOMEM);
}
sc->busdev = gpiobus_attach_bus(dev);
if (sc->busdev == NULL) {
zy7_gpio_detach(dev);
return (ENOMEM);
}
return (0);
}
static int
zy7_gpio_detach(device_t dev)
{
struct zy7_gpio_softc *sc = device_get_softc(dev);
gpiobus_detach_bus(dev);
if (sc->mem_res != NULL) {
/* Release memory resource. */
bus_release_resource(dev, SYS_RES_MEMORY,
rman_get_rid(sc->mem_res), sc->mem_res);
}
ZGPIO_LOCK_DESTROY(sc);
return (0);
}
static device_method_t zy7_gpio_methods[] = {
/* device_if */
DEVMETHOD(device_probe, zy7_gpio_probe),
DEVMETHOD(device_attach, zy7_gpio_attach),
DEVMETHOD(device_detach, zy7_gpio_detach),
/* GPIO protocol */
DEVMETHOD(gpio_get_bus, zy7_gpio_get_bus),
DEVMETHOD(gpio_pin_max, zy7_gpio_pin_max),
DEVMETHOD(gpio_pin_getname, zy7_gpio_pin_getname),
DEVMETHOD(gpio_pin_getflags, zy7_gpio_pin_getflags),
DEVMETHOD(gpio_pin_getcaps, zy7_gpio_pin_getcaps),
DEVMETHOD(gpio_pin_setflags, zy7_gpio_pin_setflags),
DEVMETHOD(gpio_pin_get, zy7_gpio_pin_get),
DEVMETHOD(gpio_pin_set, zy7_gpio_pin_set),
DEVMETHOD(gpio_pin_toggle, zy7_gpio_pin_toggle),
DEVMETHOD_END
};
static driver_t zy7_gpio_driver = {
"gpio",
zy7_gpio_methods,
sizeof(struct zy7_gpio_softc),
};
static devclass_t zy7_gpio_devclass;
DRIVER_MODULE(zy7_gpio, simplebus, zy7_gpio_driver, zy7_gpio_devclass, \
NULL, NULL);