| /* |
| * drivers/extcon/extcon_class.c |
| * |
| * External connector (extcon) class driver |
| * |
| * Copyright (C) 2012 Samsung Electronics |
| * Author: Donggeun Kim <dg77.kim@samsung.com> |
| * Author: MyungJoo Ham <myungjoo.ham@samsung.com> |
| * |
| * based on android/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/extcon.h> |
| #include <linux/slab.h> |
| |
| struct class *extcon_class; |
| #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) |
| static struct class_compat *switch_class; |
| #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ |
| |
| static ssize_t state_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); |
| |
| if (edev->print_state) { |
| int ret = edev->print_state(edev, buf); |
| |
| if (ret >= 0) |
| return ret; |
| /* Use default if failed */ |
| } |
| return sprintf(buf, "%u\n", edev->state); |
| } |
| |
| static ssize_t name_show(struct device *dev, struct device_attribute *attr, |
| char *buf) |
| { |
| struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); |
| |
| /* Optional callback given by the user */ |
| if (edev->print_name) { |
| int ret = edev->print_name(edev, buf); |
| if (ret >= 0) |
| return ret; |
| } |
| |
| return sprintf(buf, "%s\n", dev_name(edev->dev)); |
| } |
| |
| /** |
| * extcon_set_state() - Set the cable attach states of the extcon device. |
| * @edev: the extcon device |
| * @state: new cable attach status for @edev |
| * |
| * Changing the state sends uevent with environment variable containing |
| * the name of extcon device (envp[0]) and the state output (envp[1]). |
| * Tizen uses this format for extcon device to get events from ports. |
| * Android uses this format as well. |
| */ |
| void extcon_set_state(struct extcon_dev *edev, u32 state) |
| { |
| char name_buf[120]; |
| char state_buf[120]; |
| char *prop_buf; |
| char *envp[3]; |
| int env_offset = 0; |
| int length; |
| |
| if (edev->state != state) { |
| edev->state = state; |
| |
| prop_buf = (char *)get_zeroed_page(GFP_KERNEL); |
| if (prop_buf) { |
| length = name_show(edev->dev, NULL, prop_buf); |
| if (length > 0) { |
| if (prop_buf[length - 1] == '\n') |
| prop_buf[length - 1] = 0; |
| snprintf(name_buf, sizeof(name_buf), |
| "NAME=%s", prop_buf); |
| envp[env_offset++] = name_buf; |
| } |
| length = state_show(edev->dev, NULL, prop_buf); |
| if (length > 0) { |
| if (prop_buf[length - 1] == '\n') |
| prop_buf[length - 1] = 0; |
| snprintf(state_buf, sizeof(state_buf), |
| "STATE=%s", prop_buf); |
| envp[env_offset++] = state_buf; |
| } |
| envp[env_offset] = NULL; |
| kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp); |
| free_page((unsigned long)prop_buf); |
| } else { |
| dev_err(edev->dev, "out of memory in extcon_set_state\n"); |
| kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE); |
| } |
| } |
| } |
| EXPORT_SYMBOL_GPL(extcon_set_state); |
| |
| static struct device_attribute extcon_attrs[] = { |
| __ATTR_RO(state), |
| __ATTR_RO(name), |
| }; |
| |
| static int create_extcon_class(void) |
| { |
| if (!extcon_class) { |
| extcon_class = class_create(THIS_MODULE, "extcon"); |
| if (IS_ERR(extcon_class)) |
| return PTR_ERR(extcon_class); |
| extcon_class->dev_attrs = extcon_attrs; |
| |
| #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) |
| switch_class = class_compat_register("switch"); |
| if (WARN(!switch_class, "cannot allocate")) |
| return -ENOMEM; |
| #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ |
| } |
| |
| return 0; |
| } |
| |
| static void extcon_cleanup(struct extcon_dev *edev, bool skip) |
| { |
| if (!skip && get_device(edev->dev)) { |
| device_unregister(edev->dev); |
| put_device(edev->dev); |
| } |
| |
| kfree(edev->dev); |
| } |
| |
| static void extcon_dev_release(struct device *dev) |
| { |
| struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); |
| |
| extcon_cleanup(edev, true); |
| } |
| |
| /** |
| * extcon_dev_register() - Register a new extcon device |
| * @edev : the new extcon device (should be allocated before calling) |
| * @dev : the parent device for this extcon device. |
| * |
| * Among the members of edev struct, please set the "user initializing data" |
| * in any case and set the "optional callbacks" if required. However, please |
| * do not set the values of "internal data", which are initialized by |
| * this function. |
| */ |
| int extcon_dev_register(struct extcon_dev *edev, struct device *dev) |
| { |
| int ret; |
| |
| if (!extcon_class) { |
| ret = create_extcon_class(); |
| if (ret < 0) |
| return ret; |
| } |
| |
| edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL); |
| edev->dev->parent = dev; |
| edev->dev->class = extcon_class; |
| edev->dev->release = extcon_dev_release; |
| |
| dev_set_name(edev->dev, edev->name ? edev->name : dev_name(dev)); |
| ret = device_register(edev->dev); |
| if (ret) { |
| put_device(edev->dev); |
| goto err_dev; |
| } |
| #if defined(CONFIG_ANDROID) && !defined(CONFIG_ANDROID_SWITCH) |
| if (switch_class) |
| ret = class_compat_create_link(switch_class, edev->dev, |
| dev); |
| #endif /* CONFIG_ANDROID && !defined(CONFIG_ANDROID_SWITCH) */ |
| |
| dev_set_drvdata(edev->dev, edev); |
| edev->state = 0; |
| return 0; |
| |
| err_dev: |
| kfree(edev->dev); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(extcon_dev_register); |
| |
| /** |
| * extcon_dev_unregister() - Unregister the extcon device. |
| * @edev: the extcon device instance to be unregitered. |
| * |
| * Note that this does not call kfree(edev) because edev was not allocated |
| * by this class. |
| */ |
| void extcon_dev_unregister(struct extcon_dev *edev) |
| { |
| extcon_cleanup(edev, false); |
| } |
| EXPORT_SYMBOL_GPL(extcon_dev_unregister); |
| |
| static int __init extcon_class_init(void) |
| { |
| return create_extcon_class(); |
| } |
| module_init(extcon_class_init); |
| |
| static void __exit extcon_class_exit(void) |
| { |
| class_destroy(extcon_class); |
| } |
| module_exit(extcon_class_exit); |
| |
| MODULE_AUTHOR("Mike Lockwood <lockwood@android.com>"); |
| MODULE_AUTHOR("Donggeun Kim <dg77.kim@samsung.com>"); |
| MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>"); |
| MODULE_DESCRIPTION("External connector (extcon) class driver"); |
| MODULE_LICENSE("GPL"); |