From: Bartosz Golaszewski Date: Thu, 12 Feb 2015 13:53:54 +0000 (+0100) Subject: baylibre-acme: Add Linux-specific GPIO helpers. X-Git-Tag: libsigrok-0.4.0~631 X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=289eebd7ca9f1229fe7e9d318c4895069ed82d6e;p=libsigrok.git baylibre-acme: Add Linux-specific GPIO helpers. These functions allow to export, read and set GPIOs using Linux sysfs interface. Signed-off-by: Bartosz Golaszewski --- diff --git a/Makefile.am b/Makefile.am index 98e1f74e..0037d1cd 100644 --- a/Makefile.am +++ b/Makefile.am @@ -151,7 +151,9 @@ if HW_BAYLIBRE_ACME libsigrok_la_SOURCES += \ src/hardware/baylibre-acme/protocol.h \ src/hardware/baylibre-acme/protocol.c \ - src/hardware/baylibre-acme/api.c + src/hardware/baylibre-acme/api.c \ + src/hardware/baylibre-acme/gpio.h \ + src/hardware/baylibre-acme/gpio.c endif if HW_BEAGLELOGIC libsigrok_la_SOURCES += \ diff --git a/src/hardware/baylibre-acme/gpio.c b/src/hardware/baylibre-acme/gpio.c new file mode 100644 index 00000000..f7348cdf --- /dev/null +++ b/src/hardware/baylibre-acme/gpio.c @@ -0,0 +1,169 @@ +/* + * This file is part of the libsigrok project. + * + * Copyright (C) 2015 Bartosz Golaszewski + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +#include "libsigrok.h" +#include "libsigrok-internal.h" +#include "gpio.h" +#include +#include +#include +#include +#include +#include + +#define LOG_PREFIX "gpio" + +static int open_and_write(const gchar *path, const gchar *buf) +{ + FILE *fd; + ssize_t wr; + + fd = g_fopen(path, "w"); + if (!fd) { + sr_err("error opening %s: %s", path, strerror(errno)); + return -1; + } + + wr = g_fprintf(fd, "%s", buf); + fclose(fd); + if (wr < 0) { + sr_err("error writing to %s: %s", path, strerror(errno)); + return -1; + } + + return 0; +} + +SR_PRIV int sr_gpio_export(unsigned gpio) +{ + GString *path, *buf; + gboolean exported; + int status; + + path = g_string_sized_new(128); + g_string_printf(path, "/sys/class/gpio/gpio%d", gpio); + exported = g_file_test(path->str, G_FILE_TEST_IS_DIR); + g_string_free(path, TRUE); + if (exported) + return 0; /* Already exported. */ + + buf = g_string_sized_new(16); + g_string_printf(buf, "%u\n", gpio); + status = open_and_write("/sys/class/gpio/export", buf->str); + g_string_free(buf, TRUE); + + return status; +} + +SR_PRIV int sr_gpio_set_direction(unsigned gpio, unsigned direction) +{ + GString *path, *buf; + int status; + + path = g_string_sized_new(128); + buf = g_string_sized_new(16); + g_string_printf(path, "/sys/class/gpio/gpio%d/direction", gpio); + g_string_printf(buf, "%s\n", direction == GPIO_DIR_IN ? "in" : "out"); + + status = open_and_write(path->str, buf->str); + + g_string_free(path, TRUE); + g_string_free(buf, TRUE); + + return status; +} + +SR_PRIV int sr_gpio_set_value(unsigned gpio, unsigned value) +{ + GString *path, *buf; + int status; + + path = g_string_sized_new(128); + buf = g_string_sized_new(16); + g_string_printf(path, "/sys/class/gpio/gpio%d/value", gpio); + g_string_printf(buf, "%d\n", value); + + status = open_and_write(path->str, buf->str); + + g_string_free(path, TRUE); + g_string_free(buf, TRUE); + + return status; +} + +SR_PRIV int sr_gpio_get_value(int gpio) +{ + FILE *fd; + GString *path; + int ret, status; + + path = g_string_sized_new(128); + g_string_printf(path, "/sys/class/gpio/gpio%d/value", gpio); + fd = g_fopen(path->str, "r"); + if (!fd) { + sr_err("error opening %s: %s", path->str, strerror(errno)); + g_string_free(path, TRUE); + return -1; + } + + status = fscanf(fd, "%d", &ret); + fclose(fd); + if (status != 1) { + sr_err("error reading from %s: %s", path, strerror(errno)); + g_string_free(path, TRUE); + return -1; + } + + g_string_free(path, TRUE); + return ret; +} + +SR_PRIV int sr_gpio_setval_export(int gpio, int value) +{ + int status; + + status = sr_gpio_export(gpio); + if (status < 0) + return status; + + status = sr_gpio_set_direction(gpio, GPIO_DIR_OUT); + if (status < 0) + return status; + + status = sr_gpio_set_value(gpio, value); + if (status < 0) + return status; + + return 0; +} + +SR_PRIV int sr_gpio_getval_export(int gpio) +{ + int status; + + status = sr_gpio_export(gpio); + if (status < 0) + return status; + + status = sr_gpio_set_direction(gpio, GPIO_DIR_IN); + if (status < 0) + return status; + + return sr_gpio_get_value(gpio); +} diff --git a/src/hardware/baylibre-acme/gpio.h b/src/hardware/baylibre-acme/gpio.h new file mode 100644 index 00000000..8a6fde18 --- /dev/null +++ b/src/hardware/baylibre-acme/gpio.h @@ -0,0 +1,41 @@ +/* + * This file is part of the libsigrok project. + * + * Copyright (C) 2015 Bartosz Golaszewski + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see . + */ + +/* + * Linux-specific GPIO interface helpers. These functions could be moved out + * of this directory if any other driver would happen to want to use them. + */ + +#ifndef LIBSIGROK_GPIO_H +#define LIBSIGROK_GPIO_H + +enum { + GPIO_DIR_IN, + GPIO_DIR_OUT, +}; + +SR_PRIV int sr_gpio_export(unsigned gpio); +SR_PRIV int sr_gpio_set_direction(unsigned gpio, unsigned direction); +SR_PRIV int sr_gpio_set_value(unsigned gpio, unsigned value); +SR_PRIV int sr_gpio_get_value(int gpio); +/* These functions export given gpio if it's not already exported. */ +SR_PRIV int sr_gpio_setval_export(int gpio, int value); +SR_PRIV int sr_gpio_getval_export(int gpio); + +#endif /* LIBSIGROK_GPIO_H */