// SPDX-License-Identifier: GPL-2.0+ /* * f_acm.c -- USB CDC serial (ACM) function driver * * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) * Copyright (C) 2008 by David Brownell * Copyright (C) 2008 by Nokia Corporation * Copyright (C) 2009 by Samsung Electronics * Author: Michal Nazarewicz (mina86@mina86.com) */ /* #define VERBOSE_DEBUG */ #include #include #include #include #include #include "u_serial.h" /* * This CDC ACM function support just wraps control functions and * notifications around the generic serial-over-usb code. * * Because CDC ACM is standardized by the USB-IF, many host operating * systems have drivers for it. Accordingly, ACM is the preferred * interop solution for serial-port type connections. The control * models are often not necessary, and in any case don't do much in * this bare-bones implementation. * * Note that even MS-Windows has some support for ACM. However, that * support is somewhat broken because when you use ACM in a composite * device, having multiple interfaces confuses the poor OS. It doesn't * seem to understand CDC Union descriptors. The new "association" * descriptors (roughly equivalent to CDC Unions) may sometimes help. */ struct f_acm { struct gserial port; u8 ctrl_id, data_id; u8 port_num; u8 bInterfaceProtocol; u8 pending; /* lock is mostly for pending and notify_req ... they get accessed * by callbacks both from tty (open/close/break) under its spinlock, * and notify_req.complete() which can't use that lock. */ spinlock_t lock; struct usb_ep *notify; struct usb_request *notify_req; struct usb_cdc_line_coding port_line_coding; /* 8-N-1 etc */ /* SetControlLineState request -- CDC 1.1 section 6.2.14 (INPUT) */ u16 port_handshake_bits; /* SerialState notification -- CDC 1.1 section 6.3.5 (OUTPUT) */ u16 serial_state; }; static inline struct f_acm *func_to_acm(struct usb_function *f) { return container_of(f, struct f_acm, port.func); } static inline struct f_acm *port_to_acm(struct gserial *p) { return container_of(p, struct f_acm, port); } /*-------------------------------------------------------------------------*/ /* notification endpoint uses smallish and infrequent fixed-size messages */ #define GS_NOTIFY_INTERVAL_MS 32 #define GS_NOTIFY_MAXPACKET 10 /* notification + 2 bytes */ /* interface and class descriptors: */ static struct usb_interface_assoc_descriptor acm_iad_descriptor = { .bLength = sizeof acm_iad_descriptor, .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION, /* .bFirstInterface = DYNAMIC, */ .bInterfaceCount = 2, // control + data .bFunctionClass = USB_CLASS_COMM, .bFunctionSubClass = USB_CDC_SUBCLASS_ACM, /* .bFunctionProtocol = DYNAMIC */ /* .iFunction = DYNAMIC */ }; static struct usb_interface_descriptor acm_control_interface_desc = { .bLength = USB_DT_INTERFACE_SIZE, .bDescriptorType = USB_DT_INTERFACE, /* .bInterfaceNumber = DYNAMIC */ .bNumEndpoints = 1, .bInterfaceClass = USB_CLASS_COMM, .bInterfaceSubClass = USB_CDC_SUBCLASS_ACM, /* .bInterfaceProtocol = DYNAMIC */ /* .iInterface = DYNAMIC */ }; static struct usb_interface_descriptor acm_data_interface_desc = { .bLength = USB_DT_INTERFACE_SIZE, .bDescriptorType = USB_DT_INTERFACE, /* .bInterfaceNumber = DYNAMIC */ .bNumEndpoints = 2, .bInterfaceClass = USB_CLASS_CDC_DATA, .bInterfaceSubClass = 0, .bInterfaceProtocol = 0, /* .iInterface = DYNAMIC */ }; static struct usb_cdc_header_desc acm_header_desc = { .bLength = sizeof(acm_header_desc), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubType = USB_CDC_HEADER_TYPE, .bcdCDC = cpu_to_le16(0x0110), }; static struct usb_cdc_call_mgmt_descriptor acm_call_mgmt_descriptor = { .bLength = sizeof(acm_call_mgmt_descriptor), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubType = USB_CDC_CALL_MANAGEMENT_TYPE, .bmCapabilities = 0, /* .bDataInterface = DYNAMIC */ }; static struct usb_cdc_acm_descriptor acm_descriptor = { .bLength = sizeof(acm_descriptor), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubType = USB_CDC_ACM_TYPE, .bmCapabilities = USB_CDC_CAP_LINE, }; static struct usb_cdc_union_desc acm_union_desc = { .bLength = sizeof(acm_union_desc), .bDescriptorType = USB_DT_CS_INTERFACE, .bDescriptorSubType = USB_CDC_UNION_TYPE, /* .bMasterInterface0 = DYNAMIC */ /* .bSlaveInterface0 = DYNAMIC */ }; /* full speed support: */ static struct usb_endpoint_descriptor acm_fs_notify_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_INT, .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET), .bInterval = GS_NOTIFY_INTERVAL_MS, }; static struct usb_endpoint_descriptor acm_fs_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_endpoint_descriptor acm_fs_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_OUT, .bmAttributes = USB_ENDPOINT_XFER_BULK, }; static struct usb_descriptor_header *acm_fs_function[] = { (struct usb_descriptor_header *) &acm_iad_descriptor, (struct usb_descriptor_header *) &acm_control_interface_desc, (struct usb_descriptor_header *) &acm_header_desc, (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, (struct usb_descriptor_header *) &acm_descriptor, (struct usb_descriptor_header *) &acm_union_desc, (struct usb_descriptor_header *) &acm_fs_notify_desc, (struct usb_descriptor_header *) &acm_data_interface_desc, (struct usb_descriptor_header *) &acm_fs_in_desc, (struct usb_descriptor_header *) &acm_fs_out_desc, NULL, }; /* high speed support: */ static struct usb_endpoint_descriptor acm_hs_notify_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bEndpointAddress = USB_DIR_IN, .bmAttributes = USB_ENDPOINT_XFER_INT, .wMaxPacketSize = cpu_to_le16(GS_NOTIFY_MAXPACKET), .bInterval = USB_MS_TO_HS_INTERVAL(GS_NOTIFY_INTERVAL_MS), }; static struct usb_endpoint_descriptor acm_hs_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_endpoint_descriptor acm_hs_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(512), }; static struct usb_descriptor_header *acm_hs_function[] = { (struct usb_descriptor_header *) &acm_iad_descriptor, (struct usb_descriptor_header *) &acm_control_interface_desc, (struct usb_descriptor_header *) &acm_header_desc, (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, (struct usb_descriptor_header *) &acm_descriptor, (struct usb_descriptor_header *) &acm_union_desc, (struct usb_descriptor_header *) &acm_hs_notify_desc, (struct usb_descriptor_header *) &acm_data_interface_desc, (struct usb_descriptor_header *) &acm_hs_in_desc, (struct usb_descriptor_header *) &acm_hs_out_desc, NULL, }; static struct usb_endpoint_descriptor acm_ss_in_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; static struct usb_endpoint_descriptor acm_ss_out_desc = { .bLength = USB_DT_ENDPOINT_SIZE, .bDescriptorType = USB_DT_ENDPOINT, .bmAttributes = USB_ENDPOINT_XFER_BULK, .wMaxPacketSize = cpu_to_le16(1024), }; static struct usb_ss_ep_comp_descriptor acm_ss_bulk_comp_desc = { .bLength = sizeof acm_ss_bulk_comp_desc, .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, }; static struct usb_descriptor_header *acm_ss_function[] = { (struct usb_descriptor_header *) &acm_iad_descriptor, (struct usb_descriptor_header *) &acm_control_interface_desc, (struct usb_descriptor_header *) &acm_header_desc, (struct usb_descriptor_header *) &acm_call_mgmt_descriptor, (struct usb_descriptor_header *) &acm_descriptor, (struct usb_descriptor_header *) &acm_union_desc, (struct usb_descriptor_header *) &acm_hs_notify_desc, (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, (struct usb_descriptor_header *) &acm_data_interface_desc, (struct usb_descriptor_header *) &acm_ss_in_desc, (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, (struct usb_descriptor_header *) &acm_ss_out_desc, (struct usb_descriptor_header *) &acm_ss_bulk_comp_desc, NULL, }; /* string descriptors: */ #define ACM_CTRL_IDX 0 #define ACM_DATA_IDX 1 #define ACM_IAD_IDX 2 /* static strings, in UTF-8 */ static struct usb_string acm_string_defs[] = { [ACM_CTRL_IDX].s = "CDC Abstract Control Model (ACM)", [ACM_DATA_IDX].s = "CDC ACM Data", [ACM_IAD_IDX ].s = "CDC Serial", { } /* end of list */ }; static struct usb_gadget_strings acm_string_table = { .language = 0x0409, /* en-us */ .strings = acm_string_defs, }; static struct usb_gadget_strings *acm_strings[] = { &acm_string_table, NULL, }; /*-------------------------------------------------------------------------*/ /* ACM control ... data handling is delegated to tty library code. * The main task of this function is to activate and deactivate * that code based on device state; track parameters like line * speed, handshake state, and so on; and issue notifications. */ static void acm_complete_set_line_coding(struct usb_ep *ep, struct usb_request *req) { struct f_acm *acm = ep->driver_data; struct usb_composite_dev *cdev = acm->port.func.config->cdev; if (req->status != 0) { dev_dbg(&cdev->gadget->dev, "acm ttyGS%d completion, err %d\n", acm->port_num, req->status); return; } /* normal completion */ if (req->actual != sizeof(acm->port_line_coding)) { dev_dbg(&cdev->gadget->dev, "acm ttyGS%d short resp, len %d\n", acm->port_num, req->actual); usb_ep_set_halt(ep); } else { struct usb_cdc_line_coding *value = req->buf; /* REVISIT: we currently just remember this data. * If we change that, (a) validate it first, then * (b) update whatever hardware needs updating, * (c) worry about locking. This is information on * the order of 9600-8-N-1 ... most of which means * nothing unless we control a real RS232 line. */ acm->port_line_coding = *value; } } static int acm_send_break(struct gserial *port, int duration); static int acm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) { struct f_acm *acm = func_to_acm(f); struct usb_composite_dev *cdev = f->config->cdev; struct usb_request *req = cdev->req; int value = -EOPNOTSUPP; u16 w_index = le16_to_cpu(ctrl->wIndex); u16 w_value = le16_to_cpu(ctrl->wValue); u16 w_length = le16_to_cpu(ctrl->wLength); /* composite driver infrastructure handles everything except * CDC class messages; interface activation uses set_alt(). * * Note CDC spec table 4 lists the ACM request profile. It requires * encapsulated command support ... we don't handle any, and respond * to them by stalling. Options include get/set/clear comm features * (not that useful) and SEND_BREAK. */ switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { /* SET_LINE_CODING ... just read and save what the host sends */ case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) | USB_CDC_REQ_SET_LINE_CODING: if (w_length != sizeof(struct usb_cdc_line_coding) || w_index != acm->ctrl_id) goto invalid; value = w_length; cdev->gadget->ep0->driver_data = acm; req->complete = acm_complete_set_line_coding; break; /* GET_LINE_CODING ... return what host sent, or initial value */ case ((USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) | USB_CDC_REQ_GET_LINE_CODING: if (w_index != acm->ctrl_id) goto invalid; value = min_t(unsigned, w_length, sizeof(struct usb_cdc_line_coding)); memcpy(req->buf, &acm->port_line_coding, value); break; /* SET_CONTROL_LINE_STATE ... save what the host sent */ case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) | USB_CDC_REQ_SET_CONTROL_LINE_STATE: if (w_index != acm->ctrl_id) goto invalid; value = 0; /* FIXME we should not allow data to flow until the * host sets the USB_CDC_CTRL_DTR bit; and when it clears * that bit, we should return to that no-flow state. */ acm->port_handshake_bits = w_value; break; case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) | USB_CDC_REQ_SEND_BREAK: if (w_index != acm->ctrl_id) goto invalid; acm_send_break(&acm->port, w_value); break; default: invalid: dev_vdbg(&cdev->gadget->dev, "invalid control req%02x.%02x v%04x i%04x l%d\n", ctrl->bRequestType, ctrl->bRequest, w_value, w_index, w_length); } /* respond with data transfer or status phase? */ if (value >= 0) { dev_dbg(&cdev->gadget->dev, "acm ttyGS%d req%02x.%02x v%04x i%04x l%d\n", acm->port_num, ctrl->bRequestType, ctrl->bRequest, w_value, w_index, w_length); req->zero = 0; req->length = value; value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); if (value < 0) ERROR(cdev, "acm response on ttyGS%d, err %d\n", acm->port_num, value); } /* device either stalls (value < 0) or reports success */ return value; } static int acm_set_alt(struct usb_function *f, unsigned intf, unsigned alt) { struct f_acm *acm = func_to_acm(f); struct usb_composite_dev *cdev = f->config->cdev; /* we know alt == 0, so this is an activation or a reset */ if (intf == acm->ctrl_id) { if (acm->notify->enabled) { dev_vdbg(&cdev->gadget->dev, "reset acm control interface %d\n", intf); usb_ep_disable(acm->notify); } if (!acm->notify->desc) if (config_ep_by_speed(cdev->gadget, f, acm->notify)) return -EINVAL; usb_ep_enable(acm->notify); } else if (intf == acm->data_id) { if (acm->notify->enabled) { dev_dbg(&cdev->gadget->dev, "reset acm ttyGS%d\n", acm->port_num); gserial_disconnect(&acm->port); } if (!acm->port.in->desc || !acm->port.out->desc) { dev_dbg(&cdev->gadget->dev, "activate acm ttyGS%d\n", acm->port_num); if (config_ep_by_speed(cdev->gadget, f, acm->port.in) || config_ep_by_speed(cdev->gadget, f, acm->port.out)) { acm->port.in->desc = NULL; acm->port.out->desc = NULL; return -EINVAL; } } gserial_connect(&acm->port, acm->port_num); } else return -EINVAL; return 0; } static void acm_disable(struct usb_function *f) { struct f_acm *acm = func_to_acm(f); struct usb_composite_dev *cdev = f->config->cdev; dev_dbg(&cdev->gadget->dev, "acm ttyGS%d deactivated\n", acm->port_num); gserial_disconnect(&acm->port); usb_ep_disable(acm->notify); } /*-------------------------------------------------------------------------*/ /** * acm_cdc_notify - issue CDC notification to host * @acm: wraps host to be notified * @type: notification type * @value: Refer to cdc specs, wValue field. * @data: data to be sent * @length: size of data * Context: irqs blocked, acm->lock held, acm_notify_req non-null * * Returns zero on success or a negative errno. * * See section 6.3.5 of the CDC 1.1 specification for information * about the only notification we issue: SerialState change. */ static int acm_cdc_notify(struct f_acm *acm, u8 type, u16 value, void *data, unsigned length) { struct usb_ep *ep = acm->notify; struct usb_request *req; struct usb_cdc_notification *notify; const unsigned len = sizeof(*notify) + length; void *buf; int status; req = acm->notify_req; acm->notify_req = NULL; acm->pending = false; req->length = len; notify = req->buf; buf = notify + 1; notify->bmRequestType = USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE; notify->bNotificationType = type; notify->wValue = cpu_to_le16(value); notify->wIndex = cpu_to_le16(acm->ctrl_id); notify->wLength = cpu_to_le16(length); memcpy(buf, data, length); /* ep_queue() can complete immediately if it fills the fifo... */ spin_unlock(&acm->lock); status = usb_ep_queue(ep, req, GFP_ATOMIC); spin_lock(&acm->lock); if (status < 0) { ERROR(acm->port.func.config->cdev, "acm ttyGS%d can't notify serial state, %d\n", acm->port_num, status); acm->notify_req = req; } return status; } static int acm_notify_serial_state(struct f_acm *acm) { struct usb_composite_dev *cdev = acm->port.func.config->cdev; int status; __le16 serial_state; spin_lock(&acm->lock); if (acm->notify_req) { dev_dbg(&cdev->gadget->dev, "acm ttyGS%d serial state %04x\n", acm->port_num, acm->serial_state); serial_state = cpu_to_le16(acm->serial_state); status = acm_cdc_notify(acm, USB_CDC_NOTIFY_SERIAL_STATE, 0, &serial_state, sizeof(acm->serial_state)); } else { acm->pending = true; status = 0; } spin_unlock(&acm->lock); return status; } static void acm_cdc_notify_complete(struct usb_ep *ep, struct usb_request *req) { struct f_acm *acm = req->context; u8 doit = false; /* on this call path we do NOT hold the port spinlock, * which is why ACM needs its own spinlock */ spin_lock(&acm->lock); if (req->status != -ESHUTDOWN) doit = acm->pending; acm->notify_req = req; spin_unlock(&acm->lock); if (doit) acm_notify_serial_state(acm); } /* connect == the TTY link is open */ static void acm_connect(struct gserial *port) { struct f_acm *acm = port_to_acm(port); acm->serial_state |= USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD; acm_notify_serial_state(acm); } static void acm_disconnect(struct gserial *port) { struct f_acm *acm = port_to_acm(port); acm->serial_state &= ~(USB_CDC_SERIAL_STATE_DSR | USB_CDC_SERIAL_STATE_DCD); acm_notify_serial_state(acm); } static int acm_send_break(struct gserial *port, int duration) { struct f_acm *acm = port_to_acm(port); u16 state; state = acm->serial_state; state &= ~USB_CDC_SERIAL_STATE_BREAK; if (duration) state |= USB_CDC_SERIAL_STATE_BREAK; acm->serial_state = state; return acm_notify_serial_state(acm); } /*-------------------------------------------------------------------------*/ /* ACM function driver setup/binding */ static int acm_bind(struct usb_configuration *c, struct usb_function *f) { struct usb_composite_dev *cdev = c->cdev; struct f_acm *acm = func_to_acm(f); struct usb_string *us; int status; struct usb_ep *ep; /* REVISIT might want instance-specific strings to help * distinguish instances ... */ /* maybe allocate device-global string IDs, and patch descriptors */ us = usb_gstrings_attach(cdev, acm_strings, ARRAY_SIZE(acm_string_defs)); if (IS_ERR(us)) return PTR_ERR(us); acm_control_interface_desc.iInterface = us[ACM_CTRL_IDX].id; acm_data_interface_desc.iInterface = us[ACM_DATA_IDX].id; acm_iad_descriptor.iFunction = us[ACM_IAD_IDX].id; /* allocate instance-specific interface IDs, and patch descriptors */ status = usb_interface_id(c, f); if (status < 0) goto fail; acm->ctrl_id = status; acm_iad_descriptor.bFirstInterface = status; acm_control_interface_desc.bInterfaceNumber = status; acm_union_desc .bMasterInterface0 = status; status = usb_interface_id(c, f); if (status < 0) goto fail; acm->data_id = status; acm_data_interface_desc.bInterfaceNumber = status; acm_union_desc.bSlaveInterface0 = status; acm_call_mgmt_descriptor.bDataInterface = status; status = -ENODEV; /* allocate instance-specific endpoints */ ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_in_desc); if (!ep) goto fail; acm->port.in = ep; ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_out_desc); if (!ep) goto fail; acm->port.out = ep; ep = usb_ep_autoconfig(cdev->gadget, &acm_fs_notify_desc); if (!ep) goto fail; acm->notify = ep; acm_iad_descriptor.bFunctionProtocol = acm->bInterfaceProtocol; acm_control_interface_desc.bInterfaceProtocol = acm->bInterfaceProtocol; /* allocate notification */ acm->notify_req = gs_alloc_req(ep, sizeof(struct usb_cdc_notification) + 2, GFP_KERNEL); if (!acm->notify_req) goto fail; acm->notify_req->complete = acm_cdc_notify_complete; acm->notify_req->context = acm; /* support all relevant hardware speeds... we expect that when * hardware is dual speed, all bulk-capable endpoints work at * both speeds */ acm_hs_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress; acm_hs_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress; acm_hs_notify_desc.bEndpointAddress = acm_fs_notify_desc.bEndpointAddress; acm_ss_in_desc.bEndpointAddress = acm_fs_in_desc.bEndpointAddress; acm_ss_out_desc.bEndpointAddress = acm_fs_out_desc.bEndpointAddress; status = usb_assign_descriptors(f, acm_fs_function, acm_hs_function, acm_ss_function, acm_ss_function); if (status) goto fail; dev_dbg(&cdev->gadget->dev, "acm ttyGS%d: IN/%s OUT/%s NOTIFY/%s\n", acm->port_num, acm->port.in->name, acm->port.out->name, acm->notify->name); return 0; fail: if (acm->notify_req) gs_free_req(acm->notify, acm->notify_req); ERROR(cdev, "%s/%p: can't bind, err %d\n", f->name, f, status); return status; } static void acm_unbind(struct usb_configuration *c, struct usb_function *f) { struct f_acm *acm = func_to_acm(f); acm_string_defs[0].id = 0; usb_free_all_descriptors(f); if (acm->notify_req) gs_free_req(acm->notify, acm->notify_req); } static void acm_free_func(struct usb_function *f) { struct f_acm *acm = func_to_acm(f); struct f_serial_opts *opts; opts = container_of(f->fi, struct f_serial_opts, func_inst); kfree(acm); mutex_lock(&opts->lock); opts->instances--; mutex_unlock(&opts->lock); } static void acm_resume(struct usb_function *f) { struct f_acm *acm = func_to_acm(f); gserial_resume(&acm->port); } static void acm_suspend(struct usb_function *f) { struct f_acm *acm = func_to_acm(f); gserial_suspend(&acm->port); } static struct usb_function *acm_alloc_func(struct usb_function_instance *fi) { struct f_serial_opts *opts; struct f_acm *acm; acm = kzalloc(sizeof(*acm), GFP_KERNEL); if (!acm) return ERR_PTR(-ENOMEM); spin_lock_init(&acm->lock); acm->port.connect = acm_connect; acm->port.disconnect = acm_disconnect; acm->port.send_break = acm_send_break; acm->port.func.name = "acm"; acm->port.func.strings = acm_strings; /* descriptors are per-instance copies */ acm->port.func.bind = acm_bind; acm->port.func.set_alt = acm_set_alt; acm->port.func.setup = acm_setup; acm->port.func.disable = acm_disable; opts = container_of(fi, struct f_serial_opts, func_inst); mutex_lock(&opts->lock); acm->port_num = opts->port_num; acm->bInterfaceProtocol = opts->protocol; opts->instances++; mutex_unlock(&opts->lock); acm->port.func.unbind = acm_unbind; acm->port.func.free_func = acm_free_func; acm->port.func.resume = acm_resume; acm->port.func.suspend = acm_suspend; return &acm->port.func; } static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item) { return container_of(to_config_group(item), struct f_serial_opts, func_inst.group); } static void acm_attr_release(struct config_item *item) { struct f_serial_opts *opts = to_f_serial_opts(item); usb_put_function_instance(&opts->func_inst); } static struct configfs_item_operations acm_item_ops = { .release = acm_attr_release, }; #ifdef CONFIG_U_SERIAL_CONSOLE static ssize_t f_acm_console_store(struct config_item *item, const char *page, size_t count) { return gserial_set_console(to_f_serial_opts(item)->port_num, page, count); } static ssize_t f_acm_console_show(struct config_item *item, char *page) { return gserial_get_console(to_f_serial_opts(item)->port_num, page); } CONFIGFS_ATTR(f_acm_, console); #endif /* CONFIG_U_SERIAL_CONSOLE */ static ssize_t f_acm_port_num_show(struct config_item *item, char *page) { return sprintf(page, "%u\n", to_f_serial_opts(item)->port_num); } CONFIGFS_ATTR_RO(f_acm_, port_num); static ssize_t f_acm_protocol_show(struct config_item *item, char *page) { return sprintf(page, "%u\n", to_f_serial_opts(item)->protocol); } static ssize_t f_acm_protocol_store(struct config_item *item, const char *page, size_t count) { struct f_serial_opts *opts = to_f_serial_opts(item); int ret; mutex_lock(&opts->lock); if (opts->instances) { ret = -EBUSY; goto out; } ret = kstrtou8(page, 0, &opts->protocol); if (ret) goto out; ret = count; out: mutex_unlock(&opts->lock); return ret; } CONFIGFS_ATTR(f_acm_, protocol); static struct configfs_attribute *acm_attrs[] = { #ifdef CONFIG_U_SERIAL_CONSOLE &f_acm_attr_console, #endif &f_acm_attr_port_num, &f_acm_attr_protocol, NULL, }; static const struct config_item_type acm_func_type = { .ct_item_ops = &acm_item_ops, .ct_attrs = acm_attrs, .ct_owner = THIS_MODULE, }; static void acm_free_instance(struct usb_function_instance *fi) { struct f_serial_opts *opts; opts = container_of(fi, struct f_serial_opts, func_inst); gserial_free_line(opts->port_num); mutex_destroy(&opts->lock); kfree(opts); } static struct usb_function_instance *acm_alloc_instance(void) { struct f_serial_opts *opts; int ret; opts = kzalloc(sizeof(*opts), GFP_KERNEL); if (!opts) return ERR_PTR(-ENOMEM); opts->protocol = USB_CDC_ACM_PROTO_AT_V25TER; opts->func_inst.free_func_inst = acm_free_instance; mutex_init(&opts->lock); ret = gserial_alloc_line(&opts->port_num); if (ret) { kfree(opts); return ERR_PTR(ret); } config_group_init_type_name(&opts->func_inst.group, "", &acm_func_type); return &opts->func_inst; } DECLARE_USB_FUNCTION_INIT(acm, acm_alloc_instance, acm_alloc_func); MODULE_DESCRIPTION("USB CDC serial (ACM) function driver"); MODULE_LICENSE("GPL");