/* * drivers/extcon/extcon_class.c * * External connector (extcon) class driver * * Copyright (C) 2012 Samsung Electronics * Author: Donggeun Kim * Author: MyungJoo Ham * * based on android/drivers/switch/switch_class.c * Copyright (C) 2008 Google, Inc. * Author: Mike Lockwood * * 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 #include #include #include #include #include #include #include #include /* * extcon_cable_name suggests the standard cable names for commonly used * cable types. * * However, please do not use extcon_cable_name directly for extcon_dev * struct's supported_cable pointer unless your device really supports * every single port-type of the following cable names. Please choose cable * names that are actually used in your extcon device. */ const char extcon_cable_name[][CABLE_NAME_MAX + 1] = { [EXTCON_USB] = "USB", [EXTCON_USB_HOST] = "USB-Host", [EXTCON_TA] = "TA", [EXTCON_FAST_CHARGER] = "Fast-charger", [EXTCON_SLOW_CHARGER] = "Slow-charger", [EXTCON_CHARGE_DOWNSTREAM] = "Charge-downstream", [EXTCON_HDMI] = "HDMI", [EXTCON_MHL] = "MHL", [EXTCON_DVI] = "DVI", [EXTCON_VGA] = "VGA", [EXTCON_DOCK] = "Dock", [EXTCON_LINE_IN] = "Line-in", [EXTCON_LINE_OUT] = "Line-out", [EXTCON_MIC_IN] = "Microphone", [EXTCON_HEADPHONE_OUT] = "Headphone", [EXTCON_SPDIF_IN] = "SPDIF-in", [EXTCON_SPDIF_OUT] = "SPDIF-out", [EXTCON_VIDEO_IN] = "Video-in", [EXTCON_VIDEO_OUT] = "Video-out", [EXTCON_MECHANICAL] = "Mechanical", }; static struct class *extcon_class; #if defined(CONFIG_ANDROID) static struct class_compat *switch_class; #endif /* CONFIG_ANDROID */ static LIST_HEAD(extcon_dev_list); static DEFINE_MUTEX(extcon_dev_list_lock); /** * check_mutually_exclusive - Check if new_state violates mutually_exclusive * condition. * @edev: the extcon device * @new_state: new cable attach status for @edev * * Returns 0 if nothing violates. Returns the index + 1 for the first * violated condition. */ static int check_mutually_exclusive(struct extcon_dev *edev, u32 new_state) { int i = 0; if (!edev->mutually_exclusive) return 0; for (i = 0; edev->mutually_exclusive[i]; i++) { int weight; u32 correspondants = new_state & edev->mutually_exclusive[i]; /* calculate the total number of bits set */ weight = hweight32(correspondants); if (weight > 1) return i + 1; } return 0; } static ssize_t state_show(struct device *dev, struct device_attribute *attr, char *buf) { int i, count = 0; 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 */ } if (edev->max_supported == 0) return sprintf(buf, "%u\n", edev->state); for (i = 0; i < SUPPORTED_CABLE_MAX; i++) { if (!edev->supported_cable[i]) break; count += sprintf(buf + count, "%s=%d\n", edev->supported_cable[i], !!(edev->state & (1 << i))); } return count; } int extcon_set_state(struct extcon_dev *edev, u32 state); static ssize_t state_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { u32 state; ssize_t ret = 0; struct extcon_dev *edev = (struct extcon_dev *) dev_get_drvdata(dev); ret = sscanf(buf, "0x%x", &state); if (ret == 0) ret = -EINVAL; else ret = extcon_set_state(edev, state); if (ret < 0) return ret; return count; } 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)); } static ssize_t cable_name_show(struct device *dev, struct device_attribute *attr, char *buf) { struct extcon_cable *cable = container_of(attr, struct extcon_cable, attr_name); return sprintf(buf, "%s\n", cable->edev->supported_cable[cable->cable_index]); } static ssize_t cable_state_show(struct device *dev, struct device_attribute *attr, char *buf) { struct extcon_cable *cable = container_of(attr, struct extcon_cable, attr_state); return sprintf(buf, "%d\n", extcon_get_cable_state_(cable->edev, cable->cable_index)); } /** * extcon_update_state() - Update the cable attach states of the extcon device * only for the masked bits. * @edev: the extcon device * @mask: the bit mask to designate updated bits. * @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. * * Note that the notifier provides which bits are changed in the state * variable with the val parameter (second) to the callback. */ int extcon_update_state(struct extcon_dev *edev, u32 mask, u32 state) { char name_buf[120]; char state_buf[120]; char *prop_buf; char *envp[3]; int env_offset = 0; int length; unsigned long flags; spin_lock_irqsave(&edev->lock, flags); if (edev->state != ((edev->state & ~mask) | (state & mask))) { u32 old_state = edev->state; if (check_mutually_exclusive(edev, (edev->state & ~mask) | (state & mask))) { spin_unlock_irqrestore(&edev->lock, flags); return -EPERM; } edev->state &= ~mask; edev->state |= state & mask; raw_notifier_call_chain(&edev->nh, old_state, edev); /* This could be in interrupt handler */ prop_buf = (char *)get_zeroed_page(GFP_ATOMIC); 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; /* Unlock early before uevent */ spin_unlock_irqrestore(&edev->lock, flags); kobject_uevent_env(&edev->dev->kobj, KOBJ_CHANGE, envp); free_page((unsigned long)prop_buf); } else { /* Unlock early before uevent */ spin_unlock_irqrestore(&edev->lock, flags); dev_err(edev->dev, "out of memory in extcon_set_state\n"); kobject_uevent(&edev->dev->kobj, KOBJ_CHANGE); } } else { /* No changes */ spin_unlock_irqrestore(&edev->lock, flags); } return 0; } EXPORT_SYMBOL_GPL(extcon_update_state); /** * extcon_set_state() - Set the cable attach states of the extcon device. * @edev: the extcon device * @state: new cable attach status for @edev * * Note that notifier provides which bits are changed in the state * variable with the val parameter (second) to the callback. */ int extcon_set_state(struct extcon_dev *edev, u32 state) { return extcon_update_state(edev, 0xffffffff, state); } EXPORT_SYMBOL_GPL(extcon_set_state); /** * extcon_find_cable_index() - Get the cable index based on the cable name. * @edev: the extcon device that has the cable. * @cable_name: cable name to be searched. * * Note that accessing a cable state based on cable_index is faster than * cable_name because using cable_name induces a loop with strncmp(). * Thus, when get/set_cable_state is repeatedly used, using cable_index * is recommended. */ int extcon_find_cable_index(struct extcon_dev *edev, const char *cable_name) { int i; if (edev->supported_cable) { for (i = 0; edev->supported_cable[i]; i++) { if (!strncmp(edev->supported_cable[i], cable_name, CABLE_NAME_MAX)) return i; } } return -EINVAL; } EXPORT_SYMBOL_GPL(extcon_find_cable_index); /** * extcon_get_cable_state_() - Get the status of a specific cable. * @edev: the extcon device that has the cable. * @index: cable index that can be retrieved by extcon_find_cable_index(). */ int extcon_get_cable_state_(struct extcon_dev *edev, int index) { if (index < 0 || (edev->max_supported && edev->max_supported <= index)) return -EINVAL; return !!(edev->state & (1 << index)); } EXPORT_SYMBOL_GPL(extcon_get_cable_state_); /** * extcon_get_cable_state() - Get the status of a specific cable. * @edev: the extcon device that has the cable. * @cable_name: cable name. * * Note that this is slower than extcon_get_cable_state_. */ int extcon_get_cable_state(struct extcon_dev *edev, const char *cable_name) { return extcon_get_cable_state_(edev, extcon_find_cable_index (edev, cable_name)); } EXPORT_SYMBOL_GPL(extcon_get_cable_state); /** * extcon_set_cable_state_() - Set the status of a specific cable. * @edev: the extcon device that has the cable. * @index: cable index that can be retrieved by extcon_find_cable_index(). * @cable_state: the new cable status. The default semantics is * true: attached / false: detached. */ int extcon_set_cable_state_(struct extcon_dev *edev, int index, bool cable_state) { u32 state; if (index < 0 || (edev->max_supported && edev->max_supported <= index)) return -EINVAL; state = cable_state ? (1 << index) : 0; return extcon_update_state(edev, 1 << index, state); } EXPORT_SYMBOL_GPL(extcon_set_cable_state_); /** * extcon_set_cable_state() - Set the status of a specific cable. * @edev: the extcon device that has the cable. * @cable_name: cable name. * @cable_state: the new cable status. The default semantics is * true: attached / false: detached. * * Note that this is slower than extcon_set_cable_state_. */ int extcon_set_cable_state(struct extcon_dev *edev, const char *cable_name, bool cable_state) { return extcon_set_cable_state_(edev, extcon_find_cable_index (edev, cable_name), cable_state); } EXPORT_SYMBOL_GPL(extcon_set_cable_state); /** * extcon_get_extcon_dev() - Get the extcon device instance from the name * @extcon_name: The extcon name provided with extcon_dev_register() */ struct extcon_dev *extcon_get_extcon_dev(const char *extcon_name) { struct extcon_dev *sd; mutex_lock(&extcon_dev_list_lock); list_for_each_entry(sd, &extcon_dev_list, entry) { if (!strcmp(sd->name, extcon_name)) goto out; } sd = NULL; out: mutex_unlock(&extcon_dev_list_lock); return sd; } EXPORT_SYMBOL_GPL(extcon_get_extcon_dev); static int _call_per_cable(struct notifier_block *nb, unsigned long val, void *ptr) { struct extcon_specific_cable_nb *obj = container_of(nb, struct extcon_specific_cable_nb, internal_nb); struct extcon_dev *edev = ptr; if ((val & (1 << obj->cable_index)) != (edev->state & (1 << obj->cable_index))) { bool cable_state = true; obj->previous_value = val; if (val & (1 << obj->cable_index)) cable_state = false; return obj->user_nb->notifier_call(obj->user_nb, cable_state, ptr); } return NOTIFY_OK; } /** * extcon_register_interest() - Register a notifier for a state change of a * specific cable, not an entier set of cables of a * extcon device. * @obj: an empty extcon_specific_cable_nb object to be returned. * @extcon_name: the name of extcon device. * if NULL, extcon_register_interest will register * every cable with the target cable_name given. * @cable_name: the target cable name. * @nb: the notifier block to get notified. * * Provide an empty extcon_specific_cable_nb. extcon_register_interest() sets * the struct for you. * * extcon_register_interest is a helper function for those who want to get * notification for a single specific cable's status change. If a user wants * to get notification for any changes of all cables of a extcon device, * he/she should use the general extcon_register_notifier(). * * Note that the second parameter given to the callback of nb (val) is * "old_state", not the current state. The current state can be retrieved * by looking at the third pameter (edev pointer)'s state value. */ int extcon_register_interest(struct extcon_specific_cable_nb *obj, const char *extcon_name, const char *cable_name, struct notifier_block *nb) { if (!obj || !cable_name || !nb) return -EINVAL; if (extcon_name) { obj->edev = extcon_get_extcon_dev(extcon_name); if (!obj->edev) return -ENODEV; obj->cable_index = extcon_find_cable_index(obj->edev, cable_name); if (obj->cable_index < 0) return obj->cable_index; obj->user_nb = nb; obj->internal_nb.notifier_call = _call_per_cable; return raw_notifier_chain_register(&obj->edev->nh, &obj->internal_nb); } else { struct class_dev_iter iter; struct extcon_dev *extd; struct device *dev; if (!extcon_class) return -ENODEV; class_dev_iter_init(&iter, extcon_class, NULL, NULL); while ((dev = class_dev_iter_next(&iter))) { extd = (struct extcon_dev *)dev_get_drvdata(dev); if (extcon_find_cable_index(extd, cable_name) < 0) continue; class_dev_iter_exit(&iter); return extcon_register_interest(obj, extd->name, cable_name, nb); } return -ENODEV; } } EXPORT_SYMBOL_GPL(extcon_register_interest); /** * extcon_unregister_interest() - Unregister the notifier registered by * extcon_register_interest(). * @obj: the extcon_specific_cable_nb object returned by * extcon_register_interest(). */ int extcon_unregister_interest(struct extcon_specific_cable_nb *obj) { if (!obj) return -EINVAL; return raw_notifier_chain_unregister(&obj->edev->nh, &obj->internal_nb); } EXPORT_SYMBOL_GPL(extcon_unregister_interest); /** * extcon_register_notifier() - Register a notifiee to get notified by * any attach status changes from the extcon. * @edev: the extcon device. * @nb: a notifier block to be registered. * * Note that the second parameter given to the callback of nb (val) is * "old_state", not the current state. The current state can be retrieved * by looking at the third pameter (edev pointer)'s state value. */ int extcon_register_notifier(struct extcon_dev *edev, struct notifier_block *nb) { return raw_notifier_chain_register(&edev->nh, nb); } EXPORT_SYMBOL_GPL(extcon_register_notifier); /** * extcon_unregister_notifier() - Unregister a notifiee from the extcon device. * @edev: the extcon device. * @nb: a registered notifier block to be unregistered. */ int extcon_unregister_notifier(struct extcon_dev *edev, struct notifier_block *nb) { return raw_notifier_chain_unregister(&edev->nh, nb); } EXPORT_SYMBOL_GPL(extcon_unregister_notifier); static struct device_attribute extcon_attrs[] = { __ATTR(state, S_IRUGO | S_IWUSR, state_show, state_store), __ATTR_RO(name), __ATTR_NULL, }; 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) switch_class = class_compat_register("switch"); if (WARN(!switch_class, "cannot allocate")) return -ENOMEM; #endif /* CONFIG_ANDROID */ } return 0; } static void extcon_dev_release(struct device *dev) { kfree(dev); } static const char *muex_name = "mutually_exclusive"; static void dummy_sysfs_dev_release(struct device *dev) { } /** * 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, index = 0; if (!extcon_class) { ret = create_extcon_class(); if (ret < 0) return ret; } if (edev->supported_cable) { /* Get size of array */ for (index = 0; edev->supported_cable[index]; index++) ; edev->max_supported = index; } else { edev->max_supported = 0; } if (index > SUPPORTED_CABLE_MAX) { dev_err(edev->dev, "extcon: maximum number of supported cables exceeded.\n"); return -EINVAL; } edev->dev = kzalloc(sizeof(struct device), GFP_KERNEL); if (!edev->dev) return -ENOMEM; edev->dev->parent = dev; edev->dev->class = extcon_class; edev->dev->release = extcon_dev_release; edev->name = edev->name ? edev->name : dev_name(dev); dev_set_name(edev->dev, "%s", edev->name); if (edev->max_supported) { char buf[10]; char *str; struct extcon_cable *cable; edev->cables = kzalloc(sizeof(struct extcon_cable) * edev->max_supported, GFP_KERNEL); if (!edev->cables) { ret = -ENOMEM; goto err_sysfs_alloc; } for (index = 0; index < edev->max_supported; index++) { cable = &edev->cables[index]; snprintf(buf, 10, "cable.%d", index); str = kzalloc(sizeof(char) * (strlen(buf) + 1), GFP_KERNEL); if (!str) { for (index--; index >= 0; index--) { cable = &edev->cables[index]; kfree(cable->attr_g.name); } ret = -ENOMEM; goto err_alloc_cables; } strcpy(str, buf); cable->edev = edev; cable->cable_index = index; cable->attrs[0] = &cable->attr_name.attr; cable->attrs[1] = &cable->attr_state.attr; cable->attrs[2] = NULL; cable->attr_g.name = str; cable->attr_g.attrs = cable->attrs; sysfs_attr_init(&cable->attr_name.attr); cable->attr_name.attr.name = "name"; cable->attr_name.attr.mode = 0444; cable->attr_name.show = cable_name_show; sysfs_attr_init(&cable->attr_state.attr); cable->attr_state.attr.name = "state"; cable->attr_state.attr.mode = 0444; cable->attr_state.show = cable_state_show; } } if (edev->max_supported && edev->mutually_exclusive) { char buf[80]; char *name; /* Count the size of mutually_exclusive array */ for (index = 0; edev->mutually_exclusive[index]; index++) ; edev->attrs_muex = kzalloc(sizeof(struct attribute *) * (index + 1), GFP_KERNEL); if (!edev->attrs_muex) { ret = -ENOMEM; goto err_muex; } edev->d_attrs_muex = kzalloc(sizeof(struct device_attribute) * index, GFP_KERNEL); if (!edev->d_attrs_muex) { ret = -ENOMEM; kfree(edev->attrs_muex); goto err_muex; } for (index = 0; edev->mutually_exclusive[index]; index++) { sprintf(buf, "0x%x", edev->mutually_exclusive[index]); name = kzalloc(sizeof(char) * (strlen(buf) + 1), GFP_KERNEL); if (!name) { for (index--; index >= 0; index--) { kfree(edev->d_attrs_muex[index].attr. name); } kfree(edev->d_attrs_muex); kfree(edev->attrs_muex); ret = -ENOMEM; goto err_muex; } strcpy(name, buf); sysfs_attr_init(&edev->d_attrs_muex[index].attr); edev->d_attrs_muex[index].attr.name = name; edev->d_attrs_muex[index].attr.mode = 0000; edev->attrs_muex[index] = &edev->d_attrs_muex[index] .attr; } edev->attr_g_muex.name = muex_name; edev->attr_g_muex.attrs = edev->attrs_muex; } if (edev->max_supported) { edev->extcon_dev_type.groups = kzalloc(sizeof(struct attribute_group *) * (edev->max_supported + 2), GFP_KERNEL); if (!edev->extcon_dev_type.groups) { ret = -ENOMEM; goto err_alloc_groups; } edev->extcon_dev_type.name = dev_name(edev->dev); edev->extcon_dev_type.release = dummy_sysfs_dev_release; for (index = 0; index < edev->max_supported; index++) edev->extcon_dev_type.groups[index] = &edev->cables[index].attr_g; if (edev->mutually_exclusive) edev->extcon_dev_type.groups[index] = &edev->attr_g_muex; edev->dev->type = &edev->extcon_dev_type; } ret = device_register(edev->dev); if (ret) { put_device(edev->dev); goto err_dev; } #if defined(CONFIG_ANDROID) if (switch_class) ret = class_compat_create_link(switch_class, edev->dev, NULL); #endif /* CONFIG_ANDROID */ spin_lock_init(&edev->lock); RAW_INIT_NOTIFIER_HEAD(&edev->nh); dev_set_drvdata(edev->dev, edev); edev->state = 0; mutex_lock(&extcon_dev_list_lock); list_add(&edev->entry, &extcon_dev_list); mutex_unlock(&extcon_dev_list_lock); return 0; err_dev: if (edev->max_supported) kfree(edev->extcon_dev_type.groups); err_alloc_groups: if (edev->max_supported && edev->mutually_exclusive) { for (index = 0; edev->mutually_exclusive[index]; index++) kfree(edev->d_attrs_muex[index].attr.name); kfree(edev->d_attrs_muex); kfree(edev->attrs_muex); } err_muex: for (index = 0; index < edev->max_supported; index++) kfree(edev->cables[index].attr_g.name); err_alloc_cables: if (edev->max_supported) kfree(edev->cables); err_sysfs_alloc: 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 unregistered. * * Note that this does not call kfree(edev) because edev was not allocated * by this class. */ void extcon_dev_unregister(struct extcon_dev *edev) { int index; mutex_lock(&extcon_dev_list_lock); list_del(&edev->entry); mutex_unlock(&extcon_dev_list_lock); if (IS_ERR_OR_NULL(get_device(edev->dev))) { dev_err(edev->dev, "Failed to unregister extcon_dev (%s)\n", dev_name(edev->dev)); return; } if (edev->mutually_exclusive && edev->max_supported) { for (index = 0; edev->mutually_exclusive[index]; index++) kfree(edev->d_attrs_muex[index].attr.name); kfree(edev->d_attrs_muex); kfree(edev->attrs_muex); } for (index = 0; index < edev->max_supported; index++) kfree(edev->cables[index].attr_g.name); if (edev->max_supported) { kfree(edev->extcon_dev_type.groups); kfree(edev->cables); } #if defined(CONFIG_ANDROID) if (switch_class) class_compat_remove_link(switch_class, edev->dev, NULL); #endif device_unregister(edev->dev); put_device(edev->dev); } 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) { #if defined(CONFIG_ANDROID) class_compat_unregister(switch_class); #endif class_destroy(extcon_class); } module_exit(extcon_class_exit); MODULE_AUTHOR("Mike Lockwood "); MODULE_AUTHOR("Donggeun Kim "); MODULE_AUTHOR("MyungJoo Ham "); MODULE_DESCRIPTION("External connector (extcon) class driver"); MODULE_LICENSE("GPL");