1 files changed, 95 insertions, 0 deletions

diff --git a/relay_control.c b/relay_control.c
new file mode 100644
index 0000000..7b0e59c
--- /dev/null
+++ b/relay_control.c
@@ -0,0 +1,95 @@
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/gpio.h>
+#include <linux/string.h>
+
+MODULE_LICENSE("GPL");
+
+#define RELAY_K1 18
+#define RELAY_K2 23
+#define RELAY_K3 24
+#define RELAY_K4 25
+
+#define NO_OFF 0
+#define NO_ON 1
+
+static struct kobject *relay_kobject;
+
+static ssize_t set_relay(struct kobject *kobj, struct kobj_attribute *attr, const char *buff, size_t count) {
+        int relay = 0;
+        u8 v = 0;
+        sscanf(buff, "%hhd", &v);
+
+        if (strcmp(attr->attr.name, "relay1") == 0) {
+                relay = RELAY_K1;
+        } else if (strcmp(attr->attr.name, "relay2") == 0) {
+                relay = RELAY_K2;
+        } else if (strcmp(attr->attr.name, "relay3") == 0) {
+                relay = RELAY_K3;
+        } else if (strcmp(attr->attr.name, "relay4") == 0) {
+                relay = RELAY_K4;
+        }
+
+        gpio_set_value(relay, (v == 0) ? NO_OFF : NO_ON);
+        return count;
+}
+
+static ssize_t get_relay(struct kobject *kobj, struct kobj_attribute *attr, char *buff) {
+        int relay = 0;
+        if (strcmp(attr->attr.name, "relay1") == 0) {
+                relay = RELAY_K1;
+        } else if (strcmp(attr->attr.name, "relay2") == 0) {
+                relay = RELAY_K2;
+        } else if (strcmp(attr->attr.name, "relay3") == 0) {
+                relay = RELAY_K3;
+        } else if (strcmp(attr->attr.name, "relay4") == 0) {
+                relay = RELAY_K4;
+        }
+        return sprintf(buff, "%d", gpio_get_value(relay));
+}
+
+static struct kobj_attribute relay1_attribute = __ATTR(relay1, (S_IWUSR | S_IRUGO), get_relay, set_relay);
+static struct kobj_attribute relay2_attribute = __ATTR(relay2, (S_IWUSR | S_IRUGO), get_relay, set_relay);
+static struct kobj_attribute relay3_attribute = __ATTR(relay3, (S_IWUSR | S_IRUGO), get_relay, set_relay);
+static struct kobj_attribute relay4_attribute = __ATTR(relay4, (S_IWUSR | S_IRUGO), get_relay, set_relay);
+
+static int __init relay_init(void) {
+        gpio_request(RELAY_K1, "RELAY_K1");
+        gpio_request(RELAY_K2, "RELAY_K2");
+        gpio_request(RELAY_K3, "RELAY_K3");
+        gpio_request(RELAY_K4, "RELAY_K4");
+
+        gpio_direction_output(RELAY_K1, NO_ON);
+        gpio_direction_output(RELAY_K2, NO_ON);
+        gpio_direction_output(RELAY_K3, NO_ON);
+        gpio_direction_output(RELAY_K4, NO_ON);
+
+        relay_kobject = kobject_create_and_add("relay", NULL);
+
+        if (sysfs_create_file(relay_kobject, &relay1_attribute.attr)) {
+                pr_debug("failed to create relay1 sysfs!\n");
+        }
+        if (sysfs_create_file(relay_kobject, &relay2_attribute.attr)) {
+                pr_debug("failed to create relay2 sysfs!\n");
+        }
+        if (sysfs_create_file(relay_kobject, &relay3_attribute.attr)) {
+                pr_debug("failed to create relay3 sysfs!\n");
+        }
+        if (sysfs_create_file(relay_kobject, &relay4_attribute.attr)) {
+                pr_debug("failed to create relay4 sysfs!\n");
+        }
+
+        return 0;
+}
+
+static void __exit relay_exit(void) {
+        kobject_put(relay_kobject);
+
+        gpio_free(RELAY_K1);
+        gpio_free(RELAY_K2);
+        gpio_free(RELAY_K3);
+        gpio_free(RELAY_K4);
+}
+
+module_init(relay_init);
+module_exit(relay_exit);