freebsd-dev/sys/arm/broadcom/bcm2835/bcm2835_gpio.c
Oleksandr Tymoshenko 4063f92555 Add Raspberry Pi GPIO driver
Submitted by:	Luiz Otavio O Souza
2012-11-23 20:04:39 +00:00

657 lines
15 KiB
C

/*-
* Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@freebsd.org>
* Copyright (c) 2012 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/rman.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/gpio.h>
#include <machine/bus.h>
#include <machine/cpu.h>
#include <machine/cpufunc.h>
#include <machine/resource.h>
#include <machine/fdt.h>
#include <machine/frame.h>
#include <machine/intr.h>
#include <dev/fdt/fdt_common.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include "gpio_if.h"
#undef DEBUG
#ifdef DEBUG
#define dprintf(fmt, args...) do { printf("%s(): ", __func__); \
printf(fmt,##args); } while (0)
#else
#define dprintf(fmt, args...)
#endif
#define BCM_GPIO_PINS 54
#define BCM_GPIO_DEFAULT_CAPS (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT | \
GPIO_PIN_PULLUP | GPIO_PIN_PULLDOWN)
struct bcm_gpio_softc {
device_t sc_dev;
struct mtx sc_mtx;
struct resource * sc_mem_res;
struct resource * sc_irq_res;
bus_space_tag_t sc_bst;
bus_space_handle_t sc_bsh;
void * sc_intrhand;
int sc_gpio_npins;
int sc_ro_npins;
int sc_ro_pins[BCM_GPIO_PINS];
struct gpio_pin sc_gpio_pins[BCM_GPIO_PINS];
};
enum bcm_gpio_fsel {
BCM_GPIO_INPUT,
BCM_GPIO_OUTPUT,
BCM_GPIO_ALT5,
BCM_GPIO_ALT4,
BCM_GPIO_ALT0,
BCM_GPIO_ALT1,
BCM_GPIO_ALT2,
BCM_GPIO_ALT3,
};
enum bcm_gpio_pud {
BCM_GPIO_NONE,
BCM_GPIO_PULLDOWN,
BCM_GPIO_PULLUP,
};
#define BCM_GPIO_LOCK(_sc) mtx_lock(&_sc->sc_mtx)
#define BCM_GPIO_UNLOCK(_sc) mtx_unlock(&_sc->sc_mtx)
#define BCM_GPIO_GPFSEL(_bank) 0x00 + _bank * 4
#define BCM_GPIO_GPSET(_bank) 0x1c + _bank * 4
#define BCM_GPIO_GPCLR(_bank) 0x28 + _bank * 4
#define BCM_GPIO_GPLEV(_bank) 0x34 + _bank * 4
#define BCM_GPIO_GPPUD(_bank) 0x94
#define BCM_GPIO_GPPUDCLK(_bank) 0x98 + _bank * 4
#define BCM_GPIO_WRITE(_sc, _off, _val) \
bus_space_write_4(_sc->sc_bst, _sc->sc_bsh, _off, _val)
#define BCM_GPIO_READ(_sc, _off) \
bus_space_read_4(_sc->sc_bst, _sc->sc_bsh, _off)
static int
bcm_gpio_pin_is_ro(struct bcm_gpio_softc *sc, int pin)
{
int i;
for (i = 0; i < sc->sc_ro_npins; i++)
if (pin == sc->sc_ro_pins[i])
return (1);
return (0);
}
static uint32_t
bcm_gpio_get_function(struct bcm_gpio_softc *sc, uint32_t pin)
{
uint32_t bank, data, offset;
/* Five banks, 10 pins per bank, 3 bits per pin. */
bank = pin / 10;
offset = (pin - bank * 10) * 3;
BCM_GPIO_LOCK(sc);
data = (BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank)) >> offset) & 7;
BCM_GPIO_UNLOCK(sc);
#ifdef DEBUG
device_printf(sc->sc_dev, "pin %d function: ", pin);
switch (data) {
case BCM_GPIO_INPUT:
printf("input\n");
break;
case BCM_GPIO_OUTPUT:
printf("output\n");
break;
case BCM_GPIO_ALT0:
printf("alt0\n");
break;
case BCM_GPIO_ALT1:
printf("alt1\n");
break;
case BCM_GPIO_ALT2:
printf("alt2\n");
break;
case BCM_GPIO_ALT3:
printf("alt3\n");
break;
case BCM_GPIO_ALT4:
printf("alt4\n");
break;
case BCM_GPIO_ALT5:
printf("alt5\n");
break;
}
#endif
switch (data) {
case BCM_GPIO_INPUT:
return (GPIO_PIN_INPUT);
case BCM_GPIO_OUTPUT:
return (GPIO_PIN_OUTPUT);
}
return (0);
}
static void
bcm_gpio_set_function(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t f)
{
uint32_t bank, data, offset;
/* Five banks, 10 pins per bank, 3 bits per pin. */
bank = pin / 10;
offset = (pin - bank * 10) * 3;
BCM_GPIO_LOCK(sc);
data = BCM_GPIO_READ(sc, BCM_GPIO_GPFSEL(bank));
data &= ~(7 << offset);
data |= (f << offset);
BCM_GPIO_WRITE(sc, BCM_GPIO_GPFSEL(bank), data);
BCM_GPIO_UNLOCK(sc);
}
static void
bcm_gpio_set_pud(struct bcm_gpio_softc *sc, uint32_t pin, uint32_t state)
{
uint32_t bank, offset;
bank = pin / 32;
offset = pin - 32 * bank;
BCM_GPIO_LOCK(sc);
BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), state);
DELAY(10);
BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), (1 << offset));
DELAY(10);
BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUD(0), 0);
BCM_GPIO_WRITE(sc, BCM_GPIO_GPPUDCLK(bank), 0);
BCM_GPIO_UNLOCK(sc);
}
static void
bcm_gpio_pin_configure(struct bcm_gpio_softc *sc, struct gpio_pin *pin,
unsigned int flags)
{
/*
* Manage input/output.
*/
if (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
pin->gp_flags &= ~(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT);
if (flags & GPIO_PIN_OUTPUT) {
pin->gp_flags |= GPIO_PIN_OUTPUT;
bcm_gpio_set_function(sc, pin->gp_pin,
BCM_GPIO_OUTPUT);
} else {
pin->gp_flags |= GPIO_PIN_INPUT;
bcm_gpio_set_function(sc, pin->gp_pin,
BCM_GPIO_INPUT);
}
}
/* Manage Pull-up/pull-down. */
pin->gp_flags &= ~(GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN);
if (flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) {
if (flags & GPIO_PIN_PULLUP) {
pin->gp_flags |= GPIO_PIN_PULLUP;
bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLUP);
} else {
pin->gp_flags |= GPIO_PIN_PULLDOWN;
bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_PULLDOWN);
}
} else
bcm_gpio_set_pud(sc, pin->gp_pin, BCM_GPIO_NONE);
}
static int
bcm_gpio_pin_max(device_t dev, int *maxpin)
{
*maxpin = BCM_GPIO_PINS - 1;
return (0);
}
static int
bcm_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
BCM_GPIO_LOCK(sc);
*caps = sc->sc_gpio_pins[i].gp_caps;
BCM_GPIO_UNLOCK(sc);
return (0);
}
static int
bcm_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
BCM_GPIO_LOCK(sc);
*flags = sc->sc_gpio_pins[i].gp_flags;
BCM_GPIO_UNLOCK(sc);
return (0);
}
static int
bcm_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
BCM_GPIO_LOCK(sc);
memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
BCM_GPIO_UNLOCK(sc);
return (0);
}
static int
bcm_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
/* We never touch on read-only/reserved pins. */
if (bcm_gpio_pin_is_ro(sc, pin))
return (EINVAL);
/* Filter out unwanted flags. */
if ((flags &= sc->sc_gpio_pins[i].gp_caps) != flags)
return (EINVAL);
/* Can't mix input/output together. */
if ((flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) ==
(GPIO_PIN_INPUT|GPIO_PIN_OUTPUT))
return (EINVAL);
/* Can't mix pull-up/pull-down together. */
if ((flags & (GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN)) ==
(GPIO_PIN_PULLUP|GPIO_PIN_PULLDOWN))
return (EINVAL);
bcm_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags);
return (0);
}
static int
bcm_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
uint32_t bank, offset;
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
/* We never write to read-only/reserved pins. */
if (bcm_gpio_pin_is_ro(sc, pin))
return (EINVAL);
bank = pin / 32;
offset = pin - 32 * bank;
BCM_GPIO_LOCK(sc);
if (value)
BCM_GPIO_WRITE(sc, BCM_GPIO_GPSET(bank), (1 << offset));
else
BCM_GPIO_WRITE(sc, BCM_GPIO_GPCLR(bank), (1 << offset));
BCM_GPIO_UNLOCK(sc);
return (0);
}
static int
bcm_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
uint32_t bank, offset, reg_data;
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
bank = pin / 32;
offset = pin - 32 * bank;
BCM_GPIO_LOCK(sc);
reg_data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
BCM_GPIO_UNLOCK(sc);
*val = (reg_data & (1 << offset)) ? 1 : 0;
return (0);
}
static int
bcm_gpio_pin_toggle(device_t dev, uint32_t pin)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
uint32_t bank, data, offset;
int i;
for (i = 0; i < sc->sc_gpio_npins; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= sc->sc_gpio_npins)
return (EINVAL);
/* We never write to read-only/reserved pins. */
if (bcm_gpio_pin_is_ro(sc, pin))
return (EINVAL);
bank = pin / 32;
offset = pin - 32 * bank;
BCM_GPIO_LOCK(sc);
data = BCM_GPIO_READ(sc, BCM_GPIO_GPLEV(bank));
if (data & (1 << offset))
BCM_GPIO_WRITE(sc, BCM_GPIO_GPCLR(bank), (1 << offset));
else
BCM_GPIO_WRITE(sc, BCM_GPIO_GPSET(bank), (1 << offset));
BCM_GPIO_UNLOCK(sc);
return (0);
}
static int
bcm_gpio_get_ro_pins(struct bcm_gpio_softc *sc)
{
int i, len;
pcell_t pins[BCM_GPIO_PINS];
phandle_t gpio;
/* Find the gpio node to start. */
gpio = ofw_bus_get_node(sc->sc_dev);
len = OF_getproplen(gpio, "broadcom,read-only");
if (len < 0 || len > sizeof(pins))
return (-1);
if (OF_getprop(gpio, "broadcom,read-only", &pins, len) < 0)
return (-1);
sc->sc_ro_npins = len / sizeof(pcell_t);
device_printf(sc->sc_dev, "read-only pins: ");
for (i = 0; i < sc->sc_ro_npins; i++) {
sc->sc_ro_pins[i] = fdt32_to_cpu(pins[i]);
if (i > 0)
printf(",");
printf("%d", sc->sc_ro_pins[i]);
}
if (i > 0)
printf(".");
printf("\n");
return (0);
}
static int
bcm_gpio_get_reserved_pins(struct bcm_gpio_softc *sc)
{
int i, j, len, npins;
pcell_t pins[BCM_GPIO_PINS];
phandle_t gpio, node, reserved;
char name[32];
/* Get read-only pins. */
if (bcm_gpio_get_ro_pins(sc) != 0)
return (-1);
/* Find the gpio/reserved pins node to start. */
gpio = ofw_bus_get_node(sc->sc_dev);
node = OF_child(gpio);
/*
* Find reserved node
*/
reserved = 0;
while ((node != 0) && (reserved == 0)) {
len = OF_getprop(node, "name", name,
sizeof(name) - 1);
name[len] = 0;
if (strcmp(name, "reserved") == 0)
reserved = node;
node = OF_peer(node);
}
if (reserved == 0)
return (-1);
/* Get the reserved pins. */
len = OF_getproplen(reserved, "broadcom,pins");
if (len < 0 || len > sizeof(pins))
return (-1);
if (OF_getprop(reserved, "broadcom,pins", &pins, len) < 0)
return (-1);
npins = len / sizeof(pcell_t);
j = 0;
device_printf(sc->sc_dev, "reserved pins: ");
for (i = 0; i < npins; i++) {
if (i > 0)
printf(",");
printf("%d", fdt32_to_cpu(pins[i]));
/* Some pins maybe already on the list of read-only pins. */
if (bcm_gpio_pin_is_ro(sc, fdt32_to_cpu(pins[i])))
continue;
sc->sc_ro_pins[j++ + sc->sc_ro_npins] = fdt32_to_cpu(pins[i]);
}
sc->sc_ro_npins += j;
if (i > 0)
printf(".");
printf("\n");
return (0);
}
static int
bcm_gpio_probe(device_t dev)
{
if (!ofw_bus_is_compatible(dev, "broadcom,bcm2835-gpio"))
return (ENXIO);
device_set_desc(dev, "BCM2708/2835 GPIO controller");
return (BUS_PROBE_DEFAULT);
}
static int
bcm_gpio_attach(device_t dev)
{
struct bcm_gpio_softc *sc = device_get_softc(dev);
int i, j, rid;
phandle_t gpio;
sc->sc_dev = dev;
mtx_init(&sc->sc_mtx, "bcm gpio", "gpio", MTX_DEF);
rid = 0;
sc->sc_mem_res = bus_alloc_resource_any(dev, SYS_RES_MEMORY, &rid,
RF_ACTIVE);
if (!sc->sc_mem_res) {
device_printf(dev, "cannot allocate memory window\n");
return (ENXIO);
}
sc->sc_bst = rman_get_bustag(sc->sc_mem_res);
sc->sc_bsh = rman_get_bushandle(sc->sc_mem_res);
rid = 0;
sc->sc_irq_res = bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
if (!sc->sc_irq_res) {
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
device_printf(dev, "cannot allocate interrupt\n");
return (ENXIO);
}
/* Find our node. */
gpio = ofw_bus_get_node(sc->sc_dev);
if (!OF_hasprop(gpio, "gpio-controller"))
/* Node is not a GPIO controller. */
goto fail;
/*
* Find the read-only pins. These are pins we never touch or bad
* things could happen.
*/
if (bcm_gpio_get_reserved_pins(sc) == -1)
goto fail;
/* Initialize the software controlled pins. */
for (i = 0, j = 0; j < BCM_GPIO_PINS - 1; j++) {
if (bcm_gpio_pin_is_ro(sc, j))
continue;
snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
"pin %d", j);
sc->sc_gpio_pins[i].gp_pin = j;
sc->sc_gpio_pins[i].gp_caps = BCM_GPIO_DEFAULT_CAPS;
sc->sc_gpio_pins[i].gp_flags = bcm_gpio_get_function(sc, j);
i++;
}
sc->sc_gpio_npins = i;
device_add_child(dev, "gpioc", device_get_unit(dev));
device_add_child(dev, "gpiobus", device_get_unit(dev));
return (bus_generic_attach(dev));
fail:
if (sc->sc_irq_res)
bus_release_resource(dev, SYS_RES_IRQ, 0, sc->sc_irq_res);
if (sc->sc_mem_res)
bus_release_resource(dev, SYS_RES_MEMORY, 0, sc->sc_mem_res);
return (ENXIO);
}
static int
bcm_gpio_detach(device_t dev)
{
return (EBUSY);
}
static device_method_t bcm_gpio_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, bcm_gpio_probe),
DEVMETHOD(device_attach, bcm_gpio_attach),
DEVMETHOD(device_detach, bcm_gpio_detach),
/* GPIO protocol */
DEVMETHOD(gpio_pin_max, bcm_gpio_pin_max),
DEVMETHOD(gpio_pin_getname, bcm_gpio_pin_getname),
DEVMETHOD(gpio_pin_getflags, bcm_gpio_pin_getflags),
DEVMETHOD(gpio_pin_getcaps, bcm_gpio_pin_getcaps),
DEVMETHOD(gpio_pin_setflags, bcm_gpio_pin_setflags),
DEVMETHOD(gpio_pin_get, bcm_gpio_pin_get),
DEVMETHOD(gpio_pin_set, bcm_gpio_pin_set),
DEVMETHOD(gpio_pin_toggle, bcm_gpio_pin_toggle),
DEVMETHOD_END
};
static devclass_t bcm_gpio_devclass;
static driver_t bcm_gpio_driver = {
"gpio",
bcm_gpio_methods,
sizeof(struct bcm_gpio_softc),
};
DRIVER_MODULE(bcm_gpio, simplebus, bcm_gpio_driver, bcm_gpio_devclass, 0, 0);