/* Copyright (c) 2015-2016, The Linux Foundation. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and * only version 2 as published by the Free Software Foundation. * * 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 #include #include struct boardinfo { struct list_head list; struct swr_boardinfo board_info; }; static LIST_HEAD(board_list); static LIST_HEAD(swr_master_list); static DEFINE_MUTEX(board_lock); static DEFINE_IDR(master_idr); static DEFINE_MUTEX(swr_lock); static struct device_type swr_dev_type; #define SOUNDWIRE_NAME_SIZE 32 static void swr_master_put(struct swr_master *master) { if (master) put_device(&master->dev); } static struct swr_master *swr_master_get(struct swr_master *master) { if (!master || !get_device(&master->dev)) return NULL; return master; } static void swr_dev_release(struct device *dev) { struct swr_device *swr_dev = to_swr_device(dev); struct swr_master *master; if (!swr_dev) return; master = swr_dev->master; if (!master) return; mutex_lock(&master->mlock); list_del_init(&swr_dev->dev_list); mutex_unlock(&master->mlock); swr_master_put(swr_dev->master); kfree(swr_dev); } /** * swr_new_device - instantiate a new soundwire device * @master: Controller to which device is connected * @info: Describes the soundwire device * Context: can sleep * * Create a soundwire device. Binding is handled through driver model * probe/remove methods. A driver may be bound to this device when * the function gets returned. * * Returns a soundwire new device or NULL */ struct swr_device *swr_new_device(struct swr_master *master, struct swr_boardinfo const *info) { int result; struct swr_device *swr; if (!master || !swr_master_get(master)) { pr_err("%s: master is NULL\n", __func__); return NULL; } swr = kzalloc(sizeof(*swr), GFP_KERNEL); if (!swr) { dev_err(&master->dev, "cannot alloc swr_device\n"); put_device(&master->dev); return NULL; } swr->master = master; swr->addr = info->addr; strlcpy(swr->name, info->name, sizeof(swr->name)); swr->dev.type = &swr_dev_type; swr->dev.parent = &master->dev; swr->dev.bus = &soundwire_type; swr->dev.release = swr_dev_release; swr->dev.of_node = info->of_node; mutex_lock(&master->mlock); list_add_tail(&swr->dev_list, &master->devices); mutex_unlock(&master->mlock); dev_set_name(&swr->dev, "%s.%lx", swr->name, swr->addr); result = device_register(&swr->dev); if (result) { dev_err(&master->dev, "device [%s] register failed err %d\n", swr->name, result); goto err_out; } dev_dbg(&master->dev, "Device [%s] registered with bus id %s\n", swr->name, dev_name(&swr->dev)); return swr; err_out: dev_dbg(&master->dev, "Failed to register swr device %s at 0x%lx %d\n", swr->name, swr->addr, result); swr_master_put(master); kfree(swr); return NULL; } EXPORT_SYMBOL(swr_new_device); /** * swr_startup_devices - perform additional initialization for child devices * * @swr_dev: pointer to soundwire slave device * * Performs any additional initialization needed for a soundwire slave device. * This is a optional functionality defined by slave devices. * Removes the slave node from the list, in case there is any failure. */ int swr_startup_devices(struct swr_device *swr_dev) { struct swr_driver *swr_drv; struct device *dev; int ret = 0; if (!swr_dev) return -EINVAL; dev = &swr_dev->dev; if (!dev) return -EINVAL; swr_drv = to_swr_driver(dev->driver); if (!swr_drv) return -EINVAL; if (swr_drv->startup) { ret = swr_drv->startup(swr_dev); if (ret) goto out; dev_dbg(&swr_dev->dev, "%s: startup complete for device %lx\n", __func__, swr_dev->addr); } out: return ret; } EXPORT_SYMBOL(swr_startup_devices); /** * of_register_swr_devices - register child devices on to the soundwire bus * @master: pointer to soundwire master device * * Registers a soundwire device for each child node of master node which has * a "swr-devid" property * */ int of_register_swr_devices(struct swr_master *master) { struct swr_device *swr; struct device_node *node; if (!master->dev.of_node) return -EINVAL; for_each_available_child_of_node(master->dev.of_node, node) { struct swr_boardinfo info = {}; u64 addr; dev_dbg(&master->dev, "of_swr:register %s\n", node->full_name); if (of_modalias_node(node, info.name, sizeof(info.name)) < 0) { dev_err(&master->dev, "of_swr:modalias failure %s\n", node->full_name); continue; } if (of_property_read_u64(node, "reg", &addr)) { dev_err(&master->dev, "of_swr:invalid reg %s\n", node->full_name); continue; } info.addr = addr; info.of_node = of_node_get(node); swr = swr_new_device(master, &info); if (!swr) { dev_err(&master->dev, "of_swr: Register failed %s\n", node->full_name); of_node_put(node); continue; } master->num_dev++; } return 0; } EXPORT_SYMBOL(of_register_swr_devices); /** * swr_port_response - response from master to free the completed transaction * @mstr: pointer to soundwire master device * @tid: transaction id that indicates transaction to be freed. * * Master calls this function to free the compeleted transaction memory */ void swr_port_response(struct swr_master *mstr, u8 tid) { struct swr_params *txn; txn = mstr->port_txn[tid]; if (txn == NULL) { dev_err(&mstr->dev, "%s: transaction is already NULL\n", __func__); return; } mstr->port_txn[tid] = NULL; kfree(txn); } EXPORT_SYMBOL(swr_port_response); /** * swr_remove_from_group - remove soundwire slave devices from group * @dev: pointer to the soundwire slave device * dev_num: device number of the soundwire slave device * * Returns error code for failure and 0 for success */ int swr_remove_from_group(struct swr_device *dev, u8 dev_num) { struct swr_master *master; if (!dev) return -ENODEV; master = dev->master; if (!master) return -EINVAL; if (!dev->group_id) return 0; if (master->gr_sid == dev_num) return 0; if (master->remove_from_group && master->remove_from_group(master)) dev_dbg(&master->dev, "%s: falling back to GROUP_NONE\n", __func__); return 0; } EXPORT_SYMBOL(swr_remove_from_group); /** * swr_slvdev_datapath_control - Enables/Disables soundwire slave device * data path * @dev: pointer to soundwire slave device * @dev_num: device number of the soundwire slave device * * Returns error code for failure and 0 for success */ int swr_slvdev_datapath_control(struct swr_device *dev, u8 dev_num, bool enable) { struct swr_master *master; if (!dev) return -ENODEV; master = dev->master; if (!master) return -EINVAL; if (dev->group_id) { /* Broadcast */ if (master->gr_sid != dev_num) { if (!master->gr_sid) master->gr_sid = dev_num; else return 0; } } if (master->slvdev_datapath_control) master->slvdev_datapath_control(master, enable); return 0; } EXPORT_SYMBOL(swr_slvdev_datapath_control); /** * swr_connect_port - enable soundwire slave port(s) * @dev: pointer to soundwire slave device * @port_id: logical port id(s) of soundwire slave device * @num_port: number of slave device ports need to be enabled * @ch_mask: channels for each port that needs to be enabled * @ch_rate: rate at which each port/channels operate * @num_ch: number of channels for each port * * soundwire slave device call swr_connect_port API to enable all/some of * its ports and corresponding channels and channel rate. This API will * call master connect_port callback function to calculate frame structure * and enable master and slave ports */ int swr_connect_port(struct swr_device *dev, u8 *port_id, u8 num_port, u8 *ch_mask, u32 *ch_rate, u8 *num_ch) { u8 i = 0; int ret = 0; struct swr_params *txn = NULL; struct swr_params **temp_txn = NULL; struct swr_master *master = dev->master; if (!master) { pr_err("%s: Master is NULL\n", __func__); return -EINVAL; } if (num_port > SWR_MAX_DEV_PORT_NUM) { dev_err(&master->dev, "%s: num_port %d exceeds max port %d\n", __func__, num_port, SWR_MAX_DEV_PORT_NUM); return -EINVAL; } /* * create "txn" to accomodate ports enablement of * different slave devices calling swr_connect_port at the * same time. Once master process the txn data, it calls * swr_port_response() to free the transaction. Maximum * of 256 transactions can be allocated. */ txn = kzalloc(sizeof(struct swr_params), GFP_KERNEL); if (!txn) { dev_err(&master->dev, "%s: txn memory alloc failed\n", __func__); return -ENOMEM; } mutex_lock(&master->mlock); for (i = 0; i < master->last_tid; i++) { if (master->port_txn[i] == NULL) break; } if (i >= master->last_tid) { if (master->last_tid == 255) { mutex_unlock(&master->mlock); kfree(txn); dev_err(&master->dev, "%s Max tid reached\n", __func__); return -ENOMEM; } temp_txn = krealloc(master->port_txn, (i + 1) * sizeof(struct swr_params *), GFP_KERNEL); if (!temp_txn) { mutex_unlock(&master->mlock); kfree(txn); dev_err(&master->dev, "%s Not able to allocate\n" "master port transaction memory\n", __func__); return -ENOMEM; } master->port_txn = temp_txn; master->last_tid++; } master->port_txn[i] = txn; mutex_unlock(&master->mlock); txn->tid = i; txn->dev_id = dev->dev_num; txn->num_port = num_port; for (i = 0; i < num_port; i++) { txn->port_id[i] = port_id[i]; txn->num_ch[i] = num_ch[i]; txn->ch_rate[i] = ch_rate[i]; txn->ch_en[i] = ch_mask[i]; } ret = master->connect_port(master, txn); return ret; } EXPORT_SYMBOL(swr_connect_port); /** * swr_disconnect_port - disable soundwire slave port(s) * @dev: pointer to soundwire slave device * @port_id: logical port id(s) of soundwire slave device * @num_port: number of slave device ports need to be disabled * * soundwire slave device call swr_disconnect_port API to disable all/some of * its ports. This API will call master disconnect_port callback function to * disable master and slave port and (re)configure frame structure */ int swr_disconnect_port(struct swr_device *dev, u8 *port_id, u8 num_port) { u8 i = 0; int ret; struct swr_params *txn = NULL; struct swr_params **temp_txn = NULL; struct swr_master *master = dev->master; if (!master) { pr_err("%s: Master is NULL\n", __func__); return -EINVAL; } if (num_port > SWR_MAX_DEV_PORT_NUM) { dev_err(&master->dev, "%s: num_port %d exceeds max port %d\n", __func__, num_port, SWR_MAX_DEV_PORT_NUM); return -EINVAL; } txn = kzalloc(sizeof(struct swr_params), GFP_KERNEL); if (!txn) { dev_err(&master->dev, "%s: txn memory alloc failed\n", __func__); return -ENOMEM; } mutex_lock(&master->mlock); for (i = 0; i < master->last_tid; i++) { if (master->port_txn[i] == NULL) break; } if (i >= master->last_tid) { if (master->last_tid == 255) { mutex_unlock(&master->mlock); kfree(txn); dev_err(&master->dev, "%s Max tid reached\n", __func__); return -ENOMEM; } temp_txn = krealloc(master->port_txn, (i + 1) * sizeof(struct swr_params *), GFP_KERNEL); if (!temp_txn) { mutex_unlock(&master->mlock); kfree(txn); dev_err(&master->dev, "%s Not able to allocate\n" "master port transaction memory\n", __func__); return -ENOMEM; } master->port_txn = temp_txn; master->last_tid++; } master->port_txn[i] = txn; mutex_unlock(&master->mlock); txn->tid = i; txn->dev_id = dev->dev_num; txn->num_port = num_port; for (i = 0; i < num_port; i++) txn->port_id[i] = port_id[i]; ret = master->disconnect_port(master, txn); return ret; } EXPORT_SYMBOL(swr_disconnect_port); /** * swr_get_logical_dev_num - Get soundwire slave logical device number * @dev: pointer to soundwire slave device * @dev_id: physical device id of soundwire slave device * @dev_num: pointer to logical device num of soundwire slave device * * This API will get the logical device number of soundwire slave device */ int swr_get_logical_dev_num(struct swr_device *dev, u64 dev_id, u8 *dev_num) { int ret = 0; struct swr_master *master = dev->master; if (!master) { pr_err("%s: Master is NULL\n", __func__); return -EINVAL; } mutex_lock(&master->mlock); ret = master->get_logical_dev_num(master, dev_id, dev_num); if (ret) { pr_err("%s: Error %d to get logical addr for device %llx\n", __func__, ret, dev_id); } mutex_unlock(&master->mlock); return ret; } EXPORT_SYMBOL(swr_get_logical_dev_num); /** * swr_read - read soundwire slave device registers * @dev: pointer to soundwire slave device * @dev_num: logical device num of soundwire slave device * @reg_addr: base register address that needs to be read * @buf: pointer to store the values of registers from base address * @len: length of the buffer * * This API will read the value of the register address from * soundwire slave device */ int swr_read(struct swr_device *dev, u8 dev_num, u16 reg_addr, void *buf, u32 len) { struct swr_master *master = dev->master; if (!master) return -EINVAL; return master->read(master, dev_num, reg_addr, buf, len); } EXPORT_SYMBOL(swr_read); /** * swr_bulk_write - write soundwire slave device registers * @dev: pointer to soundwire slave device * @dev_num: logical device num of soundwire slave device * @reg_addr: register address of soundwire slave device * @buf: contains value of register address * @len: indicates number of registers * * This API will write the value of the register address to * soundwire slave device */ int swr_bulk_write(struct swr_device *dev, u8 dev_num, void *reg, const void *buf, size_t len) { struct swr_master *master; if (!dev || !dev->master) return -EINVAL; master = dev->master; if (dev->group_id) { if (master->gr_sid != dev_num) { if (!master->gr_sid) master->gr_sid = dev_num; else return 0; } dev_num = dev->group_id; } if (master->bulk_write) return master->bulk_write(master, dev_num, reg, buf, len); return -ENOSYS; } EXPORT_SYMBOL(swr_bulk_write); /** * swr_write - write soundwire slave device registers * @dev: pointer to soundwire slave device * @dev_num: logical device num of soundwire slave device * @reg_addr: register address of soundwire slave device * @buf: contains value of register address * * This API will write the value of the register address to * soundwire slave device */ int swr_write(struct swr_device *dev, u8 dev_num, u16 reg_addr, const void *buf) { struct swr_master *master = dev->master; if (!master) return -EINVAL; if (dev->group_id) { if (master->gr_sid != dev_num) { if (!master->gr_sid) master->gr_sid = dev_num; else return 0; } dev_num = dev->group_id; } return master->write(master, dev_num, reg_addr, buf); } EXPORT_SYMBOL(swr_write); /** * swr_device_up - Function to bringup the soundwire slave device * @swr_dev: pointer to soundwire slave device * Context: can sleep * * This API will be called by soundwire master to bringup the slave * device. */ int swr_device_up(struct swr_device *swr_dev) { struct device *dev; const struct swr_driver *sdrv; if (!swr_dev) return -EINVAL; dev = &swr_dev->dev; sdrv = to_swr_driver(dev->driver); if (!sdrv) return -EINVAL; if (sdrv->device_up) return sdrv->device_up(to_swr_device(dev)); return -ENODEV; } EXPORT_SYMBOL(swr_device_up); /** * swr_device_down - Function to call soundwire slave device down * @swr_dev: pointer to soundwire slave device * Context: can sleep * * This API will be called by soundwire master to put slave device in * shutdown state. */ int swr_device_down(struct swr_device *swr_dev) { struct device *dev; const struct swr_driver *sdrv; if (!swr_dev) return -EINVAL; dev = &swr_dev->dev; sdrv = to_swr_driver(dev->driver); if (!sdrv) return -EINVAL; if (sdrv->device_down) return sdrv->device_down(to_swr_device(dev)); return -ENODEV; } EXPORT_SYMBOL(swr_device_down); /** * swr_reset_device - reset soundwire slave device * @swr_dev: pointer to soundwire slave device * Context: can sleep * * This API will be called by soundwire master to reset the slave * device when the slave device is not responding or in undefined * state */ int swr_reset_device(struct swr_device *swr_dev) { struct device *dev; const struct swr_driver *sdrv; if (!swr_dev) return -EINVAL; dev = &swr_dev->dev; sdrv = to_swr_driver(dev->driver); if (!sdrv) return -EINVAL; if (sdrv->reset_device) return sdrv->reset_device(to_swr_device(dev)); return -ENODEV; } EXPORT_SYMBOL(swr_reset_device); /** * swr_set_device_group - Assign group id to the slave devices * @swr_dev: pointer to soundwire slave device * @id: group id to be assigned to slave device * Context: can sleep * * This API will be called either from soundwire master or slave * device to assign group id. */ int swr_set_device_group(struct swr_device *swr_dev, u8 id) { struct swr_master *master; if (!swr_dev) return -EINVAL; swr_dev->group_id = id; master = swr_dev->master; if (!id && master) master->gr_sid = 0; return 0; } EXPORT_SYMBOL(swr_set_device_group); static int swr_drv_probe(struct device *dev) { const struct swr_driver *sdrv = to_swr_driver(dev->driver); if (!sdrv) return -EINVAL; if (sdrv->probe) return sdrv->probe(to_swr_device(dev)); return -ENODEV; } static int swr_drv_remove(struct device *dev) { const struct swr_driver *sdrv = to_swr_driver(dev->driver); if (!sdrv) return -EINVAL; if (sdrv->remove) return sdrv->remove(to_swr_device(dev)); return -ENODEV; } static void swr_drv_shutdown(struct device *dev) { const struct swr_driver *sdrv = to_swr_driver(dev->driver); if (!sdrv) return; if (sdrv->shutdown) sdrv->shutdown(to_swr_device(dev)); } /** * swr_driver_register - register a soundwire driver * @drv: the driver to register * Context: can sleep */ int swr_driver_register(struct swr_driver *drv) { drv->driver.bus = &soundwire_type; if (drv->probe) drv->driver.probe = swr_drv_probe; if (drv->remove) drv->driver.remove = swr_drv_remove; if (drv->shutdown) drv->driver.shutdown = swr_drv_shutdown; return driver_register(&drv->driver); } EXPORT_SYMBOL(swr_driver_register); /** * swr_driver_unregister - unregister a soundwire driver * @drv: the driver to unregister */ void swr_driver_unregister(struct swr_driver *drv) { if (drv) driver_unregister(&drv->driver); } EXPORT_SYMBOL(swr_driver_unregister); static void swr_match_ctrl_to_boardinfo(struct swr_master *master, struct swr_boardinfo *bi) { struct swr_device *swr; if (master->bus_num != bi->bus_num) { dev_dbg(&master->dev, "%s: master# %d and bi# %d does not match\n", __func__, master->bus_num, bi->bus_num); return; } swr = swr_new_device(master, bi); if (!swr) dev_err(&master->dev, "can't create new device for %s\n", bi->swr_slave->name); } /** * swr_master_add_boarddevices - Add devices registered by board info * @master: master to which these devices are to be added to. * * This API is called by master when it is up and running. If devices * on a master were registered before master, this will make sure that * they get probed when master is up. */ void swr_master_add_boarddevices(struct swr_master *master) { struct boardinfo *bi; mutex_lock(&board_lock); list_add_tail(&master->list, &swr_master_list); list_for_each_entry(bi, &board_list, list) swr_match_ctrl_to_boardinfo(master, &bi->board_info); mutex_unlock(&board_lock); } EXPORT_SYMBOL(swr_master_add_boarddevices); static void swr_unregister_device(struct swr_device *swr) { if (swr) device_unregister(&swr->dev); } static void swr_master_release(struct device *dev) { struct swr_master *master = to_swr_master(dev); kfree(master); } #define swr_master_attr_gr NULL static struct device_type swr_master_type = { .groups = swr_master_attr_gr, .release = swr_master_release, }; static int __unregister(struct device *dev, void *null) { swr_unregister_device(to_swr_device(dev)); return 0; } /** * swr_unregister_master - unregister soundwire master controller * @master: the master being unregistered * * This API is called by master controller driver to unregister * master controller that was registered by swr_register_master API. */ void swr_unregister_master(struct swr_master *master) { int dummy; struct swr_master *m_ctrl; mutex_lock(&swr_lock); m_ctrl = idr_find(&master_idr, master->bus_num); mutex_unlock(&swr_lock); if (m_ctrl != master) return; mutex_lock(&board_lock); list_del(&master->list); mutex_unlock(&board_lock); /* free bus id */ mutex_lock(&swr_lock); idr_remove(&master_idr, master->bus_num); mutex_unlock(&swr_lock); dummy = device_for_each_child(&master->dev, NULL, __unregister); device_unregister(&master->dev); } EXPORT_SYMBOL(swr_unregister_master); /** * swr_register_master - register soundwire master controller * @master: master to be registered * * This API will register master with the framework. master->bus_num * is the desired number with which soundwire framework registers the * master. */ int swr_register_master(struct swr_master *master) { int id; int status = 0; mutex_lock(&swr_lock); id = idr_alloc(&master_idr, master, master->bus_num, master->bus_num+1, GFP_KERNEL); mutex_unlock(&swr_lock); if (id < 0) return id; master->bus_num = id; /* Can't register until driver model init */ if (WARN_ON(!soundwire_type.p)) { status = -EAGAIN; goto done; } dev_set_name(&master->dev, "swr%u", master->bus_num); master->dev.bus = &soundwire_type; master->dev.type = &swr_master_type; mutex_init(&master->mlock); status = device_register(&master->dev); if (status < 0) goto done; INIT_LIST_HEAD(&master->devices); pr_debug("%s: SWR master registered successfully %s\n", __func__, dev_name(&master->dev)); return 0; done: idr_remove(&master_idr, master->bus_num); return status; } EXPORT_SYMBOL(swr_register_master); #define swr_device_attr_gr NULL #define swr_device_uevent NULL static struct device_type swr_dev_type = { .groups = swr_device_attr_gr, .uevent = swr_device_uevent, .release = swr_dev_release, }; static const struct swr_device_id *swr_match(const struct swr_device_id *id, const struct swr_device *swr_dev) { while (id->name[0]) { if (strcmp(swr_dev->name, id->name) == 0) return id; id++; } return NULL; } static int swr_device_match(struct device *dev, struct device_driver *driver) { struct swr_device *swr_dev; struct swr_driver *drv = to_swr_driver(driver); if (!drv) return -EINVAL; if (dev->type == &swr_dev_type) swr_dev = to_swr_device(dev); else return 0; if (drv->id_table) return swr_match(drv->id_table, swr_dev) != NULL; if (driver->name) return strcmp(swr_dev->name, driver->name) == 0; return 0; } #ifdef CONFIG_PM_SLEEP static int swr_legacy_suspend(struct device *dev, pm_message_t mesg) { struct swr_device *swr_dev = NULL; struct swr_driver *driver; if (dev->type == &swr_dev_type) swr_dev = to_swr_device(dev); if (!swr_dev || !dev->driver) return 0; driver = to_swr_driver(dev->driver); if (!driver->suspend) return 0; return driver->suspend(swr_dev, mesg); } static int swr_legacy_resume(struct device *dev) { struct swr_device *swr_dev = NULL; struct swr_driver *driver; if (dev->type == &swr_dev_type) swr_dev = to_swr_device(dev); if (!swr_dev || !dev->driver) return 0; driver = to_swr_driver(dev->driver); if (!driver->resume) return 0; return driver->resume(swr_dev); } static int swr_pm_suspend(struct device *dev) { const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; if (pm) return pm_generic_suspend(dev); else return swr_legacy_suspend(dev, PMSG_SUSPEND); } static int swr_pm_resume(struct device *dev) { const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; if (pm) return pm_generic_resume(dev); else return swr_legacy_resume(dev); } #else #define swr_pm_suspend NULL #define swr_pm_resume NULL #endif /*CONFIG_PM_SLEEP*/ static const struct dev_pm_ops soundwire_pm = { .suspend = swr_pm_suspend, .resume = swr_pm_resume, SET_RUNTIME_PM_OPS( pm_generic_suspend, pm_generic_resume, NULL ) }; struct device soundwire_dev = { .init_name = "soundwire", }; struct bus_type soundwire_type = { .name = "soundwire", .match = swr_device_match, .pm = &soundwire_pm, }; EXPORT_SYMBOL(soundwire_type); static void __exit soundwire_exit(void) { device_unregister(&soundwire_dev); bus_unregister(&soundwire_type); } static int __init soundwire_init(void) { int retval; retval = bus_register(&soundwire_type); if (!retval) retval = device_register(&soundwire_dev); if (retval) bus_unregister(&soundwire_type); return retval; } postcore_initcall(soundwire_init); module_exit(soundwire_exit); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Soundwire module"); MODULE_ALIAS("platform:soundwire");