These functions allow to export, read and set GPIOs using Linux
sysfs interface.
Signed-off-by: Bartosz Golaszewski <bgolaszew...@baylibre.com>
---
Makefile.am | 4 +-
src/hardware/baylibre-acme/gpio.c | 169 ++++++++++++++++++++++++++++++++++++++
src/hardware/baylibre-acme/gpio.h | 41 +++++++++
3 files changed, 213 insertions(+), 1 deletion(-)
create mode 100644 src/hardware/baylibre-acme/gpio.c
create mode 100644 src/hardware/baylibre-acme/gpio.h
diff --git a/Makefile.am b/Makefile.am
index 98e1f74..0037d1c 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 0000000..f7348cd
--- /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 <bgolaszew...@baylibre.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+#include "gpio.h"
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+
+#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 0000000..8a6fde1
--- /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 <bgolaszew...@baylibre.com>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * 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 */
--
2.1.4
------------------------------------------------------------------------------
Dive into the World of Parallel Programming. The Go Parallel Website,
sponsored by Intel and developed in partnership with Slashdot Media, is your
hub for all things parallel software development, from weekly thought
leadership blogs to news, videos, case studies, tutorials and more. Take a
look and join the conversation now. http://goparallel.sourceforge.net/
_______________________________________________
sigrok-devel mailing list
sigrok-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/sigrok-devel
