summaryrefslogtreecommitdiffstats
path: root/common/recipes-lib/gpio/files/src/gpio.c
diff options
context:
space:
mode:
Diffstat (limited to 'common/recipes-lib/gpio/files/src/gpio.c')
-rw-r--r--common/recipes-lib/gpio/files/src/gpio.c107
1 files changed, 107 insertions, 0 deletions
diff --git a/common/recipes-lib/gpio/files/src/gpio.c b/common/recipes-lib/gpio/files/src/gpio.c
new file mode 100644
index 0000000..9c1f7a2
--- /dev/null
+++ b/common/recipes-lib/gpio/files/src/gpio.c
@@ -0,0 +1,107 @@
+/*
+ * Copyright 2014-present Facebook. All Rights Reserved.
+ *
+ * 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 2 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+//#define DEBUG
+//#define VERBOSE
+
+#include "gpio.h"
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/errno.h>
+
+#include <openbmc/log.h>
+
+void gpio_init_default(gpio_st *g) {
+ g->gs_gpio = -1;
+ g->gs_fd = -1;
+}
+
+int gpio_open(gpio_st *g, int gpio)
+{
+ char buf[128];
+ int rc;
+
+ snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%u/value", gpio);
+ rc = open(buf, O_RDWR);
+ if (rc == -1) {
+ rc = errno;
+ LOG_ERR(rc, "Failed to open %s", buf);
+ return -rc;
+ }
+ g->gs_fd = rc;
+ g->gs_gpio = gpio;
+ return 0;
+}
+
+void gpio_close(gpio_st *g)
+{
+ if (g && g->gs_fd != -1) {
+ close(g->gs_fd);
+ }
+ gpio_init_default(g);
+}
+
+gpio_value_en gpio_read(gpio_st *g)
+{
+ char buf[32] = {0};
+ gpio_value_en v;
+ lseek(g->gs_fd, 0, SEEK_SET);
+ read(g->gs_fd, buf, sizeof(buf));
+ v = atoi(buf) ? GPIO_VALUE_HIGH : GPIO_VALUE_LOW;
+ LOG_VER("read gpio=%d value=%d %d", g->gs_gpio, atoi(buf), v);
+ return v;
+}
+
+void gpio_write(gpio_st *g, gpio_value_en v)
+{
+ lseek(g->gs_fd, 0, SEEK_SET);
+ write(g->gs_fd, (v == GPIO_VALUE_HIGH) ? "1" : "0", 1);
+ LOG_VER("write gpio=%d value=%d", g->gs_gpio, v);
+}
+
+int gpio_change_direction(gpio_st *g, gpio_direction_en dir)
+{
+ char buf[128];
+ char *val;
+ int fd = -1;
+ int rc = 0;
+
+ snprintf(buf, sizeof(buf), "/sys/class/gpio/gpio%u/direction", g->gs_gpio);
+ fd = open(buf, O_WRONLY);
+ if (fd == -1) {
+ rc = errno;
+ LOG_ERR(rc, "Failed to open %s", buf);
+ return -rc;
+ }
+
+ val = (dir == GPIO_DIRECTION_IN) ? "in" : "out";
+ write(fd, val, strlen(val));
+
+ LOG_VER("change gpio=%d direction=%s", g->gs_gpio, val);
+
+ out:
+ if (fd != -1) {
+ close(fd);
+ }
+ return -rc;
+}
OpenPOWER on IntegriCloud