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Add a GPIO driver for the Raspberry Pi firmware GPIOs

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These exist on the Raspberry Pi 3 and 4 and control and external IO
expander.

Reviewed by:	manu
Sponsored by:	Innovate UK
Differential Revision:	https://reviews.freebsd.org/D25858
This commit is contained in:
Andrew Turner 2020-08-03 17:18:12 +00:00
parent ca9a39acb3
commit 9ca3eaf0bd
2 changed files with 458 additions and 0 deletions
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457
sys/arm/broadcom/bcm2835/raspberrypi_gpio.c Normal file
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@ -0,0 +1,457 @@
/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2012 Oleksandr Tymoshenko <gonzo@FreeBSD.org>
* Copyright (c) 2012-2015 Luiz Otavio O Souza <loos@FreeBSD.org>
* 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/lock.h>
#include <sys/module.h>
#include <sys/sx.h>
#include <sys/proc.h>
#include <dev/gpio/gpiobusvar.h>
#include <dev/ofw/ofw_bus.h>
#include <arm/broadcom/bcm2835/bcm2835_firmware.h>
#include "gpio_if.h"
#define RPI_FW_GPIO_PINS 8
#define RPI_FW_GPIO_BASE 128
#define RPI_FW_GPIO_DEFAULT_CAPS (GPIO_PIN_INPUT | GPIO_PIN_OUTPUT)
struct rpi_fw_gpio_softc {
device_t sc_busdev;
device_t sc_firmware;
struct sx sc_sx;
struct gpio_pin sc_gpio_pins[RPI_FW_GPIO_PINS];
uint8_t sc_gpio_state;
};
#define RPI_FW_GPIO_LOCK(_sc) sx_xlock(&(_sc)->sc_sx)
#define RPI_FW_GPIO_UNLOCK(_sc) sx_xunlock(&(_sc)->sc_sx)
static struct ofw_compat_data compat_data[] = {
{"raspberrypi,firmware-gpio", 1},
{NULL, 0}
};
static int
rpi_fw_gpio_pin_configure(struct rpi_fw_gpio_softc *sc, struct gpio_pin *pin,
unsigned int flags)
{
union msg_get_gpio_config old_cfg;
union msg_set_gpio_config new_cfg;
int rv;
bzero(&old_cfg, sizeof(old_cfg));
bzero(&new_cfg, sizeof(new_cfg));
old_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;
RPI_FW_GPIO_LOCK(sc);
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &old_cfg, sizeof(old_cfg));
if (rv == 0 && old_cfg.resp.gpio != 0)
rv = EIO;
if (rv != 0)
goto fail;
new_cfg.req.gpio = RPI_FW_GPIO_BASE + pin->gp_pin;
if (flags & GPIO_PIN_INPUT) {
new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_IN;
new_cfg.req.state = 0;
pin->gp_flags = GPIO_PIN_INPUT;
} else if (flags & GPIO_PIN_OUTPUT) {
new_cfg.req.dir = BCM2835_FIRMWARE_GPIO_OUT;
if (flags & (GPIO_PIN_PRESET_HIGH | GPIO_PIN_PRESET_LOW)) {
if (flags & GPIO_PIN_PRESET_HIGH) {
new_cfg.req.state = 1;
sc->sc_gpio_state |= (1 << pin->gp_pin);
} else {
new_cfg.req.state = 0;
sc->sc_gpio_state &= ~(1 << pin->gp_pin);
}
} else {
if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0) {
new_cfg.req.state = 1;
} else {
new_cfg.req.state = 0;
}
}
pin->gp_flags = GPIO_PIN_OUTPUT;
} else {
new_cfg.req.dir = old_cfg.resp.dir;
/* Use the old state to decide high/low */
if ((sc->sc_gpio_state & (1 << pin->gp_pin)) != 0)
new_cfg.req.state = 1;
else
new_cfg.req.state = 0;
}
new_cfg.req.pol = old_cfg.resp.pol;
new_cfg.req.term_en = 0;
new_cfg.req.term_pull_up = 0;
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_SET_GPIO_CONFIG, &new_cfg, sizeof(new_cfg));
fail:
RPI_FW_GPIO_UNLOCK(sc);
return (rv);
}
static device_t
rpi_fw_gpio_get_bus(device_t dev)
{
struct rpi_fw_gpio_softc *sc;
sc = device_get_softc(dev);
return (sc->sc_busdev);
}
static int
rpi_fw_gpio_pin_max(device_t dev, int *maxpin)
{
*maxpin = RPI_FW_GPIO_PINS - 1;
return (0);
}
static int
rpi_fw_gpio_pin_getcaps(device_t dev, uint32_t pin, uint32_t *caps)
{
struct rpi_fw_gpio_softc *sc;
int i;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
*caps = RPI_FW_GPIO_DEFAULT_CAPS;
return (0);
}
static int
rpi_fw_gpio_pin_getflags(device_t dev, uint32_t pin, uint32_t *flags)
{
struct rpi_fw_gpio_softc *sc = device_get_softc(dev);
int i;
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
RPI_FW_GPIO_LOCK(sc);
*flags = sc->sc_gpio_pins[i].gp_flags;
RPI_FW_GPIO_UNLOCK(sc);
return (0);
}
static int
rpi_fw_gpio_pin_getname(device_t dev, uint32_t pin, char *name)
{
struct rpi_fw_gpio_softc *sc;
int i;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
RPI_FW_GPIO_LOCK(sc);
memcpy(name, sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME);
RPI_FW_GPIO_UNLOCK(sc);
return (0);
}
static int
rpi_fw_gpio_pin_setflags(device_t dev, uint32_t pin, uint32_t flags)
{
struct rpi_fw_gpio_softc *sc;
int i;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
return (rpi_fw_gpio_pin_configure(sc, &sc->sc_gpio_pins[i], flags));
}
static int
rpi_fw_gpio_pin_set(device_t dev, uint32_t pin, unsigned int value)
{
struct rpi_fw_gpio_softc *sc;
union msg_set_gpio_state state;
int i, rv;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
state.req.gpio = RPI_FW_GPIO_BASE + pin;
state.req.state = value;
RPI_FW_GPIO_LOCK(sc);
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &state, sizeof(state));
/* The firmware sets gpio to 0 on success */
if (rv == 0 && state.resp.gpio != 0)
rv = EINVAL;
if (rv == 0) {
sc->sc_gpio_pins[i].gp_flags &= ~(GPIO_PIN_PRESET_HIGH |
GPIO_PIN_PRESET_LOW);
if (value)
sc->sc_gpio_state |= (1 << i);
else
sc->sc_gpio_state &= ~(1 << i);
}
RPI_FW_GPIO_UNLOCK(sc);
return (rv);
}
static int
rpi_fw_gpio_pin_get(device_t dev, uint32_t pin, unsigned int *val)
{
struct rpi_fw_gpio_softc *sc;
union msg_get_gpio_state state;
int i, rv;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
bzero(&state, sizeof(state));
state.req.gpio = RPI_FW_GPIO_BASE + pin;
RPI_FW_GPIO_LOCK(sc);
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &state, sizeof(state));
RPI_FW_GPIO_UNLOCK(sc);
/* The firmware sets gpio to 0 on success */
if (rv == 0 && state.resp.gpio != 0)
rv = EINVAL;
if (rv == 0)
*val = !state.resp.state;
return (rv);
}
static int
rpi_fw_gpio_pin_toggle(device_t dev, uint32_t pin)
{
struct rpi_fw_gpio_softc *sc;
union msg_get_gpio_state old_state;
union msg_set_gpio_state new_state;
int i, rv;
sc = device_get_softc(dev);
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
if (sc->sc_gpio_pins[i].gp_pin == pin)
break;
}
if (i >= RPI_FW_GPIO_PINS)
return (EINVAL);
bzero(&old_state, sizeof(old_state));
bzero(&new_state, sizeof(new_state));
old_state.req.gpio = RPI_FW_GPIO_BASE + pin;
new_state.req.gpio = RPI_FW_GPIO_BASE + pin;
RPI_FW_GPIO_LOCK(sc);
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_GET_GPIO_STATE, &old_state, sizeof(old_state));
/* The firmware sets gpio to 0 on success */
if (rv == 0 && old_state.resp.gpio == 0) {
/* Set the new state to invert the GPIO */
new_state.req.state = !old_state.resp.state;
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_SET_GPIO_STATE, &new_state,
sizeof(new_state));
}
if (rv == 0 && (old_state.resp.gpio != 0 || new_state.resp.gpio != 0))
rv = EINVAL;
RPI_FW_GPIO_UNLOCK(sc);
return (rv);
}
static int
rpi_fw_gpio_probe(device_t dev)
{
if (!ofw_bus_status_okay(dev))
return (ENXIO);
if (ofw_bus_search_compatible(dev, compat_data)->ocd_data == 0)
return (ENXIO);
device_set_desc(dev, "Raspberry Pi Firmware GPIO controller");
return (BUS_PROBE_DEFAULT);
}
static int
rpi_fw_gpio_attach(device_t dev)
{
union msg_get_gpio_config cfg;
struct rpi_fw_gpio_softc *sc;
char *names;
phandle_t gpio;
int i, nelems, elm_pos, rv;
sc = device_get_softc(dev);
sc->sc_firmware = device_get_parent(dev);
sx_init(&sc->sc_sx, "Raspberry Pi firmware gpio");
/* Find our node. */
gpio = ofw_bus_get_node(dev);
if (!OF_hasprop(gpio, "gpio-controller"))
/* This is not a GPIO controller. */
goto fail;
nelems = OF_getprop_alloc(gpio, "gpio-line-names", (void **)&names);
if (nelems <= 0)
names = NULL;
elm_pos = 0;
for (i = 0; i < RPI_FW_GPIO_PINS; i++) {
/* Set the current pin name */
if (names != NULL && elm_pos < nelems &&
names[elm_pos] != '\0') {
snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
"%s", names + elm_pos);
/* Find the next pin name */
elm_pos += strlen(names + elm_pos) + 1;
} else {
snprintf(sc->sc_gpio_pins[i].gp_name, GPIOMAXNAME,
"pin %d", i);
}
sc->sc_gpio_pins[i].gp_pin = i;
sc->sc_gpio_pins[i].gp_caps = RPI_FW_GPIO_DEFAULT_CAPS;
bzero(&cfg, sizeof(cfg));
cfg.req.gpio = RPI_FW_GPIO_BASE + i;
rv = bcm2835_firmware_property(sc->sc_firmware,
BCM2835_FIRMWARE_TAG_GET_GPIO_CONFIG, &cfg, sizeof(cfg));
if (rv == 0 && cfg.resp.gpio == 0) {
if (cfg.resp.dir == BCM2835_FIRMWARE_GPIO_IN)
sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
else
sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_OUTPUT;
} else {
sc->sc_gpio_pins[i].gp_flags = GPIO_PIN_INPUT;
}
}
free(names, M_OFWPROP);
sc->sc_busdev = gpiobus_attach_bus(dev);
if (sc->sc_busdev == NULL)
goto fail;
return (0);
fail:
sx_destroy(&sc->sc_sx);
return (ENXIO);
}
static int
rpi_fw_gpio_detach(device_t dev)
{
return (EBUSY);
}
static device_method_t rpi_fw_gpio_methods[] = {
/* Device interface */
DEVMETHOD(device_probe, rpi_fw_gpio_probe),
DEVMETHOD(device_attach, rpi_fw_gpio_attach),
DEVMETHOD(device_detach, rpi_fw_gpio_detach),
/* GPIO protocol */
DEVMETHOD(gpio_get_bus, rpi_fw_gpio_get_bus),
DEVMETHOD(gpio_pin_max, rpi_fw_gpio_pin_max),
DEVMETHOD(gpio_pin_getname, rpi_fw_gpio_pin_getname),
DEVMETHOD(gpio_pin_getflags, rpi_fw_gpio_pin_getflags),
DEVMETHOD(gpio_pin_getcaps, rpi_fw_gpio_pin_getcaps),
DEVMETHOD(gpio_pin_setflags, rpi_fw_gpio_pin_setflags),
DEVMETHOD(gpio_pin_get, rpi_fw_gpio_pin_get),
DEVMETHOD(gpio_pin_set, rpi_fw_gpio_pin_set),
DEVMETHOD(gpio_pin_toggle, rpi_fw_gpio_pin_toggle),
DEVMETHOD_END
};
static devclass_t rpi_fw_gpio_devclass;
static driver_t rpi_fw_gpio_driver = {
"gpio",
rpi_fw_gpio_methods,
sizeof(struct rpi_fw_gpio_softc),
};
EARLY_DRIVER_MODULE(rpi_fw_gpio, bcm2835_firmware, rpi_fw_gpio_driver,
rpi_fw_gpio_devclass, 0, 0, BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LATE);

1
sys/conf/files.arm64
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@ -108,6 +108,7 @@ arm/broadcom/bcm2835/bcm2836.c optional soc_brcm_bcm2837 fdt | soc_brcm_bcm283
arm/broadcom/bcm2835/bcm283x_dwc_fdt.c optional dwcotg fdt soc_brcm_bcm2837 | dwcotg fdt soc_brcm_bcm2838
arm/broadcom/bcm2835/bcm2838_pci.c optional soc_brcm_bcm2838 fdt pci
arm/broadcom/bcm2835/bcm2838_xhci.c optional soc_brcm_bcm2838 fdt pci xhci
arm/broadcom/bcm2835/raspberrypi_gpio.c optional soc_brcm_bcm2837 gpio | soc_brcm_bcm2838 gpio
arm/freescale/vybrid/vf_i2c.c optional vf_i2c iicbus SOC_NXP_LS
arm/mv/a37x0_gpio.c optional a37x0_gpio gpio fdt
arm/mv/a37x0_iic.c optional a37x0_iic iicbus fdt