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path: root/drivers/switch/switch_class.c
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Diffstat (limited to 'drivers/switch/switch_class.c')
-rw-r--r--drivers/switch/switch_class.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/switch/switch_class.c b/drivers/switch/switch_class.c
new file mode 100644
index 000000000000..e05fc2591147
--- /dev/null
+++ b/drivers/switch/switch_class.c
@@ -0,0 +1,174 @@
+/*
+ * drivers/switch/switch_class.c
+ *
+ * Copyright (C) 2008 Google, Inc.
+ * Author: Mike Lockwood <lockwood@android.com>
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * 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.
+ *
+*/
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/switch.h>
+
+struct class *switch_class;
+static atomic_t device_count;
+
+static ssize_t state_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct switch_dev *sdev = (struct switch_dev *)
+ dev_get_drvdata(dev);
+
+ if (sdev->print_state) {
+ int ret = sdev->print_state(sdev, buf);
+ if (ret >= 0)
+ return ret;
+ }
+ return sprintf(buf, "%d\n", sdev->state);
+}
+
+static ssize_t name_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct switch_dev *sdev = (struct switch_dev *)
+ dev_get_drvdata(dev);
+
+ if (sdev->print_name) {
+ int ret = sdev->print_name(sdev, buf);
+ if (ret >= 0)
+ return ret;
+ }
+ return sprintf(buf, "%s\n", sdev->name);
+}
+
+static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, state_show, NULL);
+static DEVICE_ATTR(name, S_IRUGO | S_IWUSR, name_show, NULL);
+
+void switch_set_state(struct switch_dev *sdev, int state)
+{
+ char name_buf[120];
+ char state_buf[120];
+ char *prop_buf;
+ char *envp[3];
+ int env_offset = 0;
+ int length;
+
+ if (sdev->state != state) {
+ sdev->state = state;
+
+ prop_buf = (char *)get_zeroed_page(GFP_KERNEL);
+ if (prop_buf) {
+ length = name_show(sdev->dev, NULL, prop_buf);
+ if (length > 0) {
+ if (prop_buf[length - 1] == '\n')
+ prop_buf[length - 1] = 0;
+ snprintf(name_buf, sizeof(name_buf),
+ "SWITCH_NAME=%s", prop_buf);
+ envp[env_offset++] = name_buf;
+ }
+ length = state_show(sdev->dev, NULL, prop_buf);
+ if (length > 0) {
+ if (prop_buf[length - 1] == '\n')
+ prop_buf[length - 1] = 0;
+ snprintf(state_buf, sizeof(state_buf),
+ "SWITCH_STATE=%s", prop_buf);
+ envp[env_offset++] = state_buf;
+ }
+ envp[env_offset] = NULL;
+ kobject_uevent_env(&sdev->dev->kobj, KOBJ_CHANGE, envp);
+ free_page((unsigned long)prop_buf);
+ } else {
+ printk(KERN_ERR "out of memory in switch_set_state\n");
+ kobject_uevent(&sdev->dev->kobj, KOBJ_CHANGE);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(switch_set_state);
+
+static int create_switch_class(void)
+{
+ if (!switch_class) {
+ switch_class = class_create(THIS_MODULE, "switch");
+ if (IS_ERR(switch_class))
+ return PTR_ERR(switch_class);
+ atomic_set(&device_count, 0);
+ }
+
+ return 0;
+}
+
+int switch_dev_register(struct switch_dev *sdev)
+{
+ int ret;
+
+ if (!switch_class) {
+ ret = create_switch_class();
+ if (ret < 0)
+ return ret;
+ }
+
+ sdev->index = atomic_inc_return(&device_count);
+ sdev->dev = device_create(switch_class, NULL,
+ MKDEV(0, sdev->index), NULL, sdev->name);
+ if (IS_ERR(sdev->dev))
+ return PTR_ERR(sdev->dev);
+
+ ret = device_create_file(sdev->dev, &dev_attr_state);
+ if (ret < 0)
+ goto err_create_file_1;
+ ret = device_create_file(sdev->dev, &dev_attr_name);
+ if (ret < 0)
+ goto err_create_file_2;
+
+ dev_set_drvdata(sdev->dev, sdev);
+ sdev->state = 0;
+ return 0;
+
+err_create_file_2:
+ device_remove_file(sdev->dev, &dev_attr_state);
+err_create_file_1:
+ device_destroy(switch_class, MKDEV(0, sdev->index));
+ printk(KERN_ERR "switch: Failed to register driver %s\n", sdev->name);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(switch_dev_register);
+
+void switch_dev_unregister(struct switch_dev *sdev)
+{
+ device_remove_file(sdev->dev, &dev_attr_name);
+ device_remove_file(sdev->dev, &dev_attr_state);
+ device_destroy(switch_class, MKDEV(0, sdev->index));
+ dev_set_drvdata(sdev->dev, NULL);
+}
+EXPORT_SYMBOL_GPL(switch_dev_unregister);
+
+static int __init switch_class_init(void)
+{
+ return create_switch_class();
+}
+
+static void __exit switch_class_exit(void)
+{
+ class_destroy(switch_class);
+}
+
+module_init(switch_class_init);
+module_exit(switch_class_exit);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("Switch class driver");
+MODULE_LICENSE("GPL");