summaryrefslogtreecommitdiff
path: root/drivers/switch
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/switch')
-rw-r--r--drivers/switch/Kconfig15
-rw-r--r--drivers/switch/Makefile4
-rw-r--r--drivers/switch/switch_class.c174
-rw-r--r--drivers/switch/switch_gpio.c172
4 files changed, 365 insertions, 0 deletions
diff --git a/drivers/switch/Kconfig b/drivers/switch/Kconfig
new file mode 100644
index 000000000000..52385914b9ae
--- /dev/null
+++ b/drivers/switch/Kconfig
@@ -0,0 +1,15 @@
+menuconfig SWITCH
+ tristate "Switch class support"
+ help
+ Say Y here to enable switch class support. This allows
+ monitoring switches by userspace via sysfs and uevent.
+
+if SWITCH
+
+config SWITCH_GPIO
+ tristate "GPIO Swith support"
+ depends on GENERIC_GPIO
+ help
+ Say Y here to enable GPIO based switch support.
+
+endif # SWITCH
diff --git a/drivers/switch/Makefile b/drivers/switch/Makefile
new file mode 100644
index 000000000000..f7606ed4a719
--- /dev/null
+++ b/drivers/switch/Makefile
@@ -0,0 +1,4 @@
+# Switch Class Driver
+obj-$(CONFIG_SWITCH) += switch_class.o
+obj-$(CONFIG_SWITCH_GPIO) += switch_gpio.o
+
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");
diff --git a/drivers/switch/switch_gpio.c b/drivers/switch/switch_gpio.c
new file mode 100644
index 000000000000..7e9faa211e48
--- /dev/null
+++ b/drivers/switch/switch_gpio.c
@@ -0,0 +1,172 @@
+/*
+ * drivers/switch/switch_gpio.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/kernel.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/switch.h>
+#include <linux/workqueue.h>
+#include <linux/gpio.h>
+
+struct gpio_switch_data {
+ struct switch_dev sdev;
+ unsigned gpio;
+ const char *name_on;
+ const char *name_off;
+ const char *state_on;
+ const char *state_off;
+ int irq;
+ struct work_struct work;
+};
+
+static void gpio_switch_work(struct work_struct *work)
+{
+ int state;
+ struct gpio_switch_data *data =
+ container_of(work, struct gpio_switch_data, work);
+
+ state = gpio_get_value(data->gpio);
+ switch_set_state(&data->sdev, state);
+}
+
+static irqreturn_t gpio_irq_handler(int irq, void *dev_id)
+{
+ struct gpio_switch_data *switch_data =
+ (struct gpio_switch_data *)dev_id;
+
+ schedule_work(&switch_data->work);
+ return IRQ_HANDLED;
+}
+
+static ssize_t switch_gpio_print_state(struct switch_dev *sdev, char *buf)
+{
+ struct gpio_switch_data *switch_data =
+ container_of(sdev, struct gpio_switch_data, sdev);
+ const char *state;
+ if (switch_get_state(sdev))
+ state = switch_data->state_on;
+ else
+ state = switch_data->state_off;
+
+ if (state)
+ return sprintf(buf, "%s\n", state);
+ return -1;
+}
+
+static int gpio_switch_probe(struct platform_device *pdev)
+{
+ struct gpio_switch_platform_data *pdata = pdev->dev.platform_data;
+ struct gpio_switch_data *switch_data;
+ int ret = 0;
+
+ if (!pdata)
+ return -EBUSY;
+
+ switch_data = kzalloc(sizeof(struct gpio_switch_data), GFP_KERNEL);
+ if (!switch_data)
+ return -ENOMEM;
+
+ switch_data->sdev.name = pdata->name;
+ switch_data->gpio = pdata->gpio;
+ switch_data->name_on = pdata->name_on;
+ switch_data->name_off = pdata->name_off;
+ switch_data->state_on = pdata->state_on;
+ switch_data->state_off = pdata->state_off;
+ switch_data->sdev.print_state = switch_gpio_print_state;
+
+ ret = switch_dev_register(&switch_data->sdev);
+ if (ret < 0)
+ goto err_switch_dev_register;
+
+ ret = gpio_request(switch_data->gpio, pdev->name);
+ if (ret < 0)
+ goto err_request_gpio;
+
+ ret = gpio_direction_input(switch_data->gpio);
+ if (ret < 0)
+ goto err_set_gpio_input;
+
+ INIT_WORK(&switch_data->work, gpio_switch_work);
+
+ switch_data->irq = gpio_to_irq(switch_data->gpio);
+ if (switch_data->irq < 0) {
+ ret = switch_data->irq;
+ goto err_detect_irq_num_failed;
+ }
+
+ ret = request_irq(switch_data->irq, gpio_irq_handler,
+ IRQF_TRIGGER_LOW, pdev->name, switch_data);
+ if (ret < 0)
+ goto err_request_irq;
+
+ /* Perform initial detection */
+ gpio_switch_work(&switch_data->work);
+
+ return 0;
+
+err_request_irq:
+err_detect_irq_num_failed:
+err_set_gpio_input:
+ gpio_free(switch_data->gpio);
+err_request_gpio:
+ switch_dev_unregister(&switch_data->sdev);
+err_switch_dev_register:
+ kfree(switch_data);
+
+ return ret;
+}
+
+static int __devexit gpio_switch_remove(struct platform_device *pdev)
+{
+ struct gpio_switch_data *switch_data = platform_get_drvdata(pdev);
+
+ cancel_work_sync(&switch_data->work);
+ gpio_free(switch_data->gpio);
+ switch_dev_unregister(&switch_data->sdev);
+ kfree(switch_data);
+
+ return 0;
+}
+
+static struct platform_driver gpio_switch_driver = {
+ .probe = gpio_switch_probe,
+ .remove = __devexit_p(gpio_switch_remove),
+ .driver = {
+ .name = "switch-gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init gpio_switch_init(void)
+{
+ return platform_driver_register(&gpio_switch_driver);
+}
+
+static void __exit gpio_switch_exit(void)
+{
+ platform_driver_unregister(&gpio_switch_driver);
+}
+
+module_init(gpio_switch_init);
+module_exit(gpio_switch_exit);
+
+MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>");
+MODULE_DESCRIPTION("GPIO Switch driver");
+MODULE_LICENSE("GPL");
generated by cgit v1.2.3 (git 2.0.4) at 2024-12-27 12:51:03 +0000