freebsd-dev/lib/libgpio/gpio.c

279 lines
5.9 KiB
C

/*-
* Copyright (c) 2013-2014 Rui Paulo <rpaulo@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 ``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 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.
*
* $FreeBSD$
*/
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <libgpio.h>
gpio_handle_t
gpio_open(unsigned int unit)
{
char device[16];
snprintf(device, sizeof(device), "/dev/gpioc%u", unit);
return (gpio_open_device(device));
}
gpio_handle_t
gpio_open_device(const char *device)
{
int fd, maxpins;
int serr;
fd = open(device, O_RDONLY);
if (fd < 0)
return (GPIO_INVALID_HANDLE);
/*
* Check whether a simple ioctl works.
*/
if (ioctl(fd, GPIOMAXPIN, &maxpins) < 0) {
serr = errno;
close(fd);
errno = serr;
return (GPIO_INVALID_HANDLE);
}
return (fd);
}
void
gpio_close(gpio_handle_t handle)
{
close(handle);
}
int
gpio_pin_list(gpio_handle_t handle, gpio_config_t **pcfgs)
{
int maxpins, i;
gpio_config_t *cfgs;
*pcfgs = NULL;
if (ioctl(handle, GPIOMAXPIN, &maxpins) < 0)
return (-1);
/* Reasonable values. */
if (maxpins < 0 || maxpins > 4096) {
errno = EINVAL;
return (-1);
}
cfgs = calloc(maxpins + 1, sizeof(*cfgs));
if (cfgs == NULL)
return (-1);
for (i = 0; i <= maxpins; i++) {
cfgs[i].g_pin = i;
gpio_pin_config(handle, &cfgs[i]);
}
*pcfgs = cfgs;
return (maxpins);
}
int
gpio_pin_config(gpio_handle_t handle, gpio_config_t *cfg)
{
struct gpio_pin gppin;
if (cfg == NULL)
return (-1);
gppin.gp_pin = cfg->g_pin;
if (ioctl(handle, GPIOGETCONFIG, &gppin) < 0)
return (-1);
strlcpy(cfg->g_name, gppin.gp_name, GPIOMAXNAME);
cfg->g_caps = gppin.gp_caps;
cfg->g_flags = gppin.gp_flags;
return (0);
}
int
gpio_pin_set_name(gpio_handle_t handle, gpio_pin_t pin, char *name)
{
struct gpio_pin gppin;
if (name == NULL)
return (-1);
bzero(&gppin, sizeof(gppin));
gppin.gp_pin = pin;
strlcpy(gppin.gp_name, name, GPIOMAXNAME);
if (ioctl(handle, GPIOSETNAME, &gppin) < 0)
return (-1);
return (0);
}
int
gpio_pin_set_flags(gpio_handle_t handle, gpio_config_t *cfg)
{
struct gpio_pin gppin;
if (cfg == NULL)
return (-1);
gppin.gp_pin = cfg->g_pin;
gppin.gp_flags = cfg->g_flags;
if (ioctl(handle, GPIOSETCONFIG, &gppin) < 0)
return (-1);
return (0);
}
gpio_value_t
gpio_pin_get(gpio_handle_t handle, gpio_pin_t pin)
{
struct gpio_req gpreq;
bzero(&gpreq, sizeof(gpreq));
gpreq.gp_pin = pin;
if (ioctl(handle, GPIOGET, &gpreq) < 0)
return (GPIO_VALUE_INVALID);
return (gpreq.gp_value);
}
int
gpio_pin_set(gpio_handle_t handle, gpio_pin_t pin, gpio_value_t value)
{
struct gpio_req gpreq;
if (value == GPIO_VALUE_INVALID)
return (-1);
bzero(&gpreq, sizeof(gpreq));
gpreq.gp_pin = pin;
gpreq.gp_value = value;
if (ioctl(handle, GPIOSET, &gpreq) < 0)
return (-1);
return (0);
}
int
gpio_pin_toggle(gpio_handle_t handle, gpio_pin_t pin)
{
struct gpio_req gpreq;
bzero(&gpreq, sizeof(gpreq));
gpreq.gp_pin = pin;
if (ioctl(handle, GPIOTOGGLE, &gpreq) < 0)
return (-1);
return (0);
}
int
gpio_pin_low(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set(handle, pin, GPIO_VALUE_LOW));
}
int
gpio_pin_high(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set(handle, pin, GPIO_VALUE_HIGH));
}
static int
gpio_pin_set_flag(gpio_handle_t handle, gpio_pin_t pin, uint32_t flag)
{
gpio_config_t cfg;
bzero(&cfg, sizeof(cfg));
cfg.g_pin = pin;
if (gpio_pin_config(handle, &cfg) < 0)
return (-1);
cfg.g_flags = flag;
return (gpio_pin_set_flags(handle, &cfg));
}
int
gpio_pin_input(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INPUT));
}
int
gpio_pin_output(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_OUTPUT));
}
int
gpio_pin_opendrain(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_OPENDRAIN));
}
int
gpio_pin_pushpull(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PUSHPULL));
}
int
gpio_pin_tristate(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_TRISTATE));
}
int
gpio_pin_pullup(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULLUP));
}
int
gpio_pin_pulldown(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULLDOWN));
}
int
gpio_pin_invin(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INVIN));
}
int
gpio_pin_invout(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_INVOUT));
}
int
gpio_pin_pulsate(gpio_handle_t handle, gpio_pin_t pin)
{
return (gpio_pin_set_flag(handle, pin, GPIO_PIN_PULSATE));
}