diff options
Diffstat (limited to 'drivers/switch/switch_class.c')
| -rw-r--r-- | drivers/switch/switch_class.c | 174 |
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"); |