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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/usb/gadget/function/f_ecm.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/usb/gadget/function/f_ecm.c')
-rw-r--r-- | drivers/usb/gadget/function/f_ecm.c | 965 |
1 files changed, 965 insertions, 0 deletions
diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c new file mode 100644 index 000000000..ffe2486fc --- /dev/null +++ b/drivers/usb/gadget/function/f_ecm.c @@ -0,0 +1,965 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * f_ecm.c -- USB CDC Ethernet (ECM) link function driver + * + * Copyright (C) 2003-2005,2008 David Brownell + * Copyright (C) 2008 Nokia Corporation + */ + +/* #define VERBOSE_DEBUG */ + +#include <linux/slab.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/etherdevice.h> + +#include "u_ether.h" +#include "u_ether_configfs.h" +#include "u_ecm.h" + + +/* + * This function is a "CDC Ethernet Networking Control Model" (CDC ECM) + * Ethernet link. The data transfer model is simple (packets sent and + * received over bulk endpoints using normal short packet termination), + * and the control model exposes various data and optional notifications. + * + * ECM is well standardized and (except for Microsoft) supported by most + * operating systems with USB host support. It's the preferred interop + * solution for Ethernet over USB, at least for firmware based solutions. + * (Hardware solutions tend to be more minimalist.) A newer and simpler + * "Ethernet Emulation Model" (CDC EEM) hasn't yet caught on. + * + * Note that ECM requires the use of "alternate settings" for its data + * interface. This means that the set_alt() method has real work to do, + * and also means that a get_alt() method is required. + */ + + +enum ecm_notify_state { + ECM_NOTIFY_NONE, /* don't notify */ + ECM_NOTIFY_CONNECT, /* issue CONNECT next */ + ECM_NOTIFY_SPEED, /* issue SPEED_CHANGE next */ +}; + +struct f_ecm { + struct gether port; + u8 ctrl_id, data_id; + + char ethaddr[14]; + + struct usb_ep *notify; + struct usb_request *notify_req; + u8 notify_state; + atomic_t notify_count; + bool is_open; + + /* FIXME is_open needs some irq-ish locking + * ... possibly the same as port.ioport + */ +}; + +static inline struct f_ecm *func_to_ecm(struct usb_function *f) +{ + return container_of(f, struct f_ecm, port.func); +} + +/* peak (theoretical) bulk transfer rate in bits-per-second */ +static inline unsigned ecm_bitrate(struct usb_gadget *g) +{ + if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER) + return 13 * 1024 * 8 * 1000 * 8; + else if (gadget_is_dualspeed(g) && g->speed == USB_SPEED_HIGH) + return 13 * 512 * 8 * 1000 * 8; + else + return 19 * 64 * 1 * 1000 * 8; +} + +/*-------------------------------------------------------------------------*/ + +/* + * Include the status endpoint if we can, even though it's optional. + * + * Use wMaxPacketSize big enough to fit CDC_NOTIFY_SPEED_CHANGE in one + * packet, to simplify cancellation; and a big transfer interval, to + * waste less bandwidth. + * + * Some drivers (like Linux 2.4 cdc-ether!) "need" it to exist even + * if they ignore the connect/disconnect notifications that real aether + * can provide. More advanced cdc configurations might want to support + * encapsulated commands (vendor-specific, using control-OUT). + */ + +#define ECM_STATUS_INTERVAL_MS 32 +#define ECM_STATUS_BYTECOUNT 16 /* 8 byte header + data */ + + +/* interface descriptor: */ + +static struct usb_interface_assoc_descriptor +ecm_iad_descriptor = { + .bLength = sizeof ecm_iad_descriptor, + .bDescriptorType = USB_DT_INTERFACE_ASSOCIATION, + + /* .bFirstInterface = DYNAMIC, */ + .bInterfaceCount = 2, /* control + data */ + .bFunctionClass = USB_CLASS_COMM, + .bFunctionSubClass = USB_CDC_SUBCLASS_ETHERNET, + .bFunctionProtocol = USB_CDC_PROTO_NONE, + /* .iFunction = DYNAMIC */ +}; + + +static struct usb_interface_descriptor ecm_control_intf = { + .bLength = sizeof ecm_control_intf, + .bDescriptorType = USB_DT_INTERFACE, + + /* .bInterfaceNumber = DYNAMIC */ + /* status endpoint is optional; this could be patched later */ + .bNumEndpoints = 1, + .bInterfaceClass = USB_CLASS_COMM, + .bInterfaceSubClass = USB_CDC_SUBCLASS_ETHERNET, + .bInterfaceProtocol = USB_CDC_PROTO_NONE, + /* .iInterface = DYNAMIC */ +}; + +static struct usb_cdc_header_desc ecm_header_desc = { + .bLength = sizeof ecm_header_desc, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_HEADER_TYPE, + + .bcdCDC = cpu_to_le16(0x0110), +}; + +static struct usb_cdc_union_desc ecm_union_desc = { + .bLength = sizeof(ecm_union_desc), + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_UNION_TYPE, + /* .bMasterInterface0 = DYNAMIC */ + /* .bSlaveInterface0 = DYNAMIC */ +}; + +static struct usb_cdc_ether_desc ecm_desc = { + .bLength = sizeof ecm_desc, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_ETHERNET_TYPE, + + /* this descriptor actually adds value, surprise! */ + /* .iMACAddress = DYNAMIC */ + .bmEthernetStatistics = cpu_to_le32(0), /* no statistics */ + .wMaxSegmentSize = cpu_to_le16(ETH_FRAME_LEN), + .wNumberMCFilters = cpu_to_le16(0), + .bNumberPowerFilters = 0, +}; + +/* the default data interface has no endpoints ... */ + +static struct usb_interface_descriptor ecm_data_nop_intf = { + .bLength = sizeof ecm_data_nop_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 1, + .bAlternateSetting = 0, + .bNumEndpoints = 0, + .bInterfaceClass = USB_CLASS_CDC_DATA, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + /* .iInterface = DYNAMIC */ +}; + +/* ... but the "real" data interface has two bulk endpoints */ + +static struct usb_interface_descriptor ecm_data_intf = { + .bLength = sizeof ecm_data_intf, + .bDescriptorType = USB_DT_INTERFACE, + + .bInterfaceNumber = 1, + .bAlternateSetting = 1, + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_CDC_DATA, + .bInterfaceSubClass = 0, + .bInterfaceProtocol = 0, + /* .iInterface = DYNAMIC */ +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor fs_ecm_notify_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT), + .bInterval = ECM_STATUS_INTERVAL_MS, +}; + +static struct usb_endpoint_descriptor fs_ecm_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 fs_ecm_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 *ecm_fs_function[] = { + /* CDC ECM control descriptors */ + (struct usb_descriptor_header *) &ecm_iad_descriptor, + (struct usb_descriptor_header *) &ecm_control_intf, + (struct usb_descriptor_header *) &ecm_header_desc, + (struct usb_descriptor_header *) &ecm_union_desc, + (struct usb_descriptor_header *) &ecm_desc, + + /* NOTE: status endpoint might need to be removed */ + (struct usb_descriptor_header *) &fs_ecm_notify_desc, + + /* data interface, altsettings 0 and 1 */ + (struct usb_descriptor_header *) &ecm_data_nop_intf, + (struct usb_descriptor_header *) &ecm_data_intf, + (struct usb_descriptor_header *) &fs_ecm_in_desc, + (struct usb_descriptor_header *) &fs_ecm_out_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor hs_ecm_notify_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT), + .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS), +}; + +static struct usb_endpoint_descriptor hs_ecm_in_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_endpoint_descriptor hs_ecm_out_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(512), +}; + +static struct usb_descriptor_header *ecm_hs_function[] = { + /* CDC ECM control descriptors */ + (struct usb_descriptor_header *) &ecm_iad_descriptor, + (struct usb_descriptor_header *) &ecm_control_intf, + (struct usb_descriptor_header *) &ecm_header_desc, + (struct usb_descriptor_header *) &ecm_union_desc, + (struct usb_descriptor_header *) &ecm_desc, + + /* NOTE: status endpoint might need to be removed */ + (struct usb_descriptor_header *) &hs_ecm_notify_desc, + + /* data interface, altsettings 0 and 1 */ + (struct usb_descriptor_header *) &ecm_data_nop_intf, + (struct usb_descriptor_header *) &ecm_data_intf, + (struct usb_descriptor_header *) &hs_ecm_in_desc, + (struct usb_descriptor_header *) &hs_ecm_out_desc, + NULL, +}; + +/* super speed support: */ + +static struct usb_endpoint_descriptor ss_ecm_notify_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_INT, + .wMaxPacketSize = cpu_to_le16(ECM_STATUS_BYTECOUNT), + .bInterval = USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS), +}; + +static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = { + .bLength = sizeof ss_ecm_intr_comp_desc, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + + /* the following 3 values can be tweaked if necessary */ + /* .bMaxBurst = 0, */ + /* .bmAttributes = 0, */ + .wBytesPerInterval = cpu_to_le16(ECM_STATUS_BYTECOUNT), +}; + +static struct usb_endpoint_descriptor ss_ecm_in_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_endpoint_descriptor ss_ecm_out_desc = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = cpu_to_le16(1024), +}; + +static struct usb_ss_ep_comp_descriptor ss_ecm_bulk_comp_desc = { + .bLength = sizeof ss_ecm_bulk_comp_desc, + .bDescriptorType = USB_DT_SS_ENDPOINT_COMP, + + /* the following 2 values can be tweaked if necessary */ + /* .bMaxBurst = 0, */ + /* .bmAttributes = 0, */ +}; + +static struct usb_descriptor_header *ecm_ss_function[] = { + /* CDC ECM control descriptors */ + (struct usb_descriptor_header *) &ecm_iad_descriptor, + (struct usb_descriptor_header *) &ecm_control_intf, + (struct usb_descriptor_header *) &ecm_header_desc, + (struct usb_descriptor_header *) &ecm_union_desc, + (struct usb_descriptor_header *) &ecm_desc, + + /* NOTE: status endpoint might need to be removed */ + (struct usb_descriptor_header *) &ss_ecm_notify_desc, + (struct usb_descriptor_header *) &ss_ecm_intr_comp_desc, + + /* data interface, altsettings 0 and 1 */ + (struct usb_descriptor_header *) &ecm_data_nop_intf, + (struct usb_descriptor_header *) &ecm_data_intf, + (struct usb_descriptor_header *) &ss_ecm_in_desc, + (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc, + (struct usb_descriptor_header *) &ss_ecm_out_desc, + (struct usb_descriptor_header *) &ss_ecm_bulk_comp_desc, + NULL, +}; + +/* string descriptors: */ + +static struct usb_string ecm_string_defs[] = { + [0].s = "CDC Ethernet Control Model (ECM)", + [1].s = "", + [2].s = "CDC Ethernet Data", + [3].s = "CDC ECM", + { } /* end of list */ +}; + +static struct usb_gadget_strings ecm_string_table = { + .language = 0x0409, /* en-us */ + .strings = ecm_string_defs, +}; + +static struct usb_gadget_strings *ecm_strings[] = { + &ecm_string_table, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +static void ecm_do_notify(struct f_ecm *ecm) +{ + struct usb_request *req = ecm->notify_req; + struct usb_cdc_notification *event; + struct usb_composite_dev *cdev = ecm->port.func.config->cdev; + __le32 *data; + int status; + + /* notification already in flight? */ + if (atomic_read(&ecm->notify_count)) + return; + + event = req->buf; + switch (ecm->notify_state) { + case ECM_NOTIFY_NONE: + return; + + case ECM_NOTIFY_CONNECT: + event->bNotificationType = USB_CDC_NOTIFY_NETWORK_CONNECTION; + if (ecm->is_open) + event->wValue = cpu_to_le16(1); + else + event->wValue = cpu_to_le16(0); + event->wLength = 0; + req->length = sizeof *event; + + DBG(cdev, "notify connect %s\n", + ecm->is_open ? "true" : "false"); + ecm->notify_state = ECM_NOTIFY_SPEED; + break; + + case ECM_NOTIFY_SPEED: + event->bNotificationType = USB_CDC_NOTIFY_SPEED_CHANGE; + event->wValue = cpu_to_le16(0); + event->wLength = cpu_to_le16(8); + req->length = ECM_STATUS_BYTECOUNT; + + /* SPEED_CHANGE data is up/down speeds in bits/sec */ + data = req->buf + sizeof *event; + data[0] = cpu_to_le32(ecm_bitrate(cdev->gadget)); + data[1] = data[0]; + + DBG(cdev, "notify speed %d\n", ecm_bitrate(cdev->gadget)); + ecm->notify_state = ECM_NOTIFY_NONE; + break; + } + event->bmRequestType = 0xA1; + event->wIndex = cpu_to_le16(ecm->ctrl_id); + + atomic_inc(&ecm->notify_count); + status = usb_ep_queue(ecm->notify, req, GFP_ATOMIC); + if (status < 0) { + atomic_dec(&ecm->notify_count); + DBG(cdev, "notify --> %d\n", status); + } +} + +static void ecm_notify(struct f_ecm *ecm) +{ + /* NOTE on most versions of Linux, host side cdc-ethernet + * won't listen for notifications until its netdevice opens. + * The first notification then sits in the FIFO for a long + * time, and the second one is queued. + */ + ecm->notify_state = ECM_NOTIFY_CONNECT; + ecm_do_notify(ecm); +} + +static void ecm_notify_complete(struct usb_ep *ep, struct usb_request *req) +{ + struct f_ecm *ecm = req->context; + struct usb_composite_dev *cdev = ecm->port.func.config->cdev; + struct usb_cdc_notification *event = req->buf; + + switch (req->status) { + case 0: + /* no fault */ + atomic_dec(&ecm->notify_count); + break; + case -ECONNRESET: + case -ESHUTDOWN: + atomic_set(&ecm->notify_count, 0); + ecm->notify_state = ECM_NOTIFY_NONE; + break; + default: + DBG(cdev, "event %02x --> %d\n", + event->bNotificationType, req->status); + atomic_dec(&ecm->notify_count); + break; + } + ecm_do_notify(ecm); +} + +static int ecm_setup(struct usb_function *f, const struct usb_ctrlrequest *ctrl) +{ + struct f_ecm *ecm = func_to_ecm(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(). + */ + switch ((ctrl->bRequestType << 8) | ctrl->bRequest) { + case ((USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE) << 8) + | USB_CDC_SET_ETHERNET_PACKET_FILTER: + /* see 6.2.30: no data, wIndex = interface, + * wValue = packet filter bitmap + */ + if (w_length != 0 || w_index != ecm->ctrl_id) + goto invalid; + DBG(cdev, "packet filter %02x\n", w_value); + /* REVISIT locking of cdc_filter. This assumes the UDC + * driver won't have a concurrent packet TX irq running on + * another CPU; or that if it does, this write is atomic... + */ + ecm->port.cdc_filter = w_value; + value = 0; + break; + + /* and optionally: + * case USB_CDC_SEND_ENCAPSULATED_COMMAND: + * case USB_CDC_GET_ENCAPSULATED_RESPONSE: + * case USB_CDC_SET_ETHERNET_MULTICAST_FILTERS: + * case USB_CDC_SET_ETHERNET_PM_PATTERN_FILTER: + * case USB_CDC_GET_ETHERNET_PM_PATTERN_FILTER: + * case USB_CDC_GET_ETHERNET_STATISTIC: + */ + + default: +invalid: + DBG(cdev, "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) { + DBG(cdev, "ecm req%02x.%02x v%04x i%04x l%d\n", + 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, "ecm req %02x.%02x response err %d\n", + ctrl->bRequestType, ctrl->bRequest, + value); + } + + /* device either stalls (value < 0) or reports success */ + return value; +} + + +static int ecm_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct f_ecm *ecm = func_to_ecm(f); + struct usb_composite_dev *cdev = f->config->cdev; + + /* Control interface has only altsetting 0 */ + if (intf == ecm->ctrl_id) { + if (alt != 0) + goto fail; + + VDBG(cdev, "reset ecm control %d\n", intf); + usb_ep_disable(ecm->notify); + if (!(ecm->notify->desc)) { + VDBG(cdev, "init ecm ctrl %d\n", intf); + if (config_ep_by_speed(cdev->gadget, f, ecm->notify)) + goto fail; + } + usb_ep_enable(ecm->notify); + + /* Data interface has two altsettings, 0 and 1 */ + } else if (intf == ecm->data_id) { + if (alt > 1) + goto fail; + + if (ecm->port.in_ep->enabled) { + DBG(cdev, "reset ecm\n"); + gether_disconnect(&ecm->port); + } + + if (!ecm->port.in_ep->desc || + !ecm->port.out_ep->desc) { + DBG(cdev, "init ecm\n"); + if (config_ep_by_speed(cdev->gadget, f, + ecm->port.in_ep) || + config_ep_by_speed(cdev->gadget, f, + ecm->port.out_ep)) { + ecm->port.in_ep->desc = NULL; + ecm->port.out_ep->desc = NULL; + goto fail; + } + } + + /* CDC Ethernet only sends data in non-default altsettings. + * Changing altsettings resets filters, statistics, etc. + */ + if (alt == 1) { + struct net_device *net; + + /* Enable zlps by default for ECM conformance; + * override for musb_hdrc (avoids txdma ovhead). + */ + ecm->port.is_zlp_ok = + gadget_is_zlp_supported(cdev->gadget); + ecm->port.cdc_filter = DEFAULT_FILTER; + DBG(cdev, "activate ecm\n"); + net = gether_connect(&ecm->port); + if (IS_ERR(net)) + return PTR_ERR(net); + } + + /* NOTE this can be a minor disagreement with the ECM spec, + * which says speed notifications will "always" follow + * connection notifications. But we allow one connect to + * follow another (if the first is in flight), and instead + * just guarantee that a speed notification is always sent. + */ + ecm_notify(ecm); + } else + goto fail; + + return 0; +fail: + return -EINVAL; +} + +/* Because the data interface supports multiple altsettings, + * this ECM function *MUST* implement a get_alt() method. + */ +static int ecm_get_alt(struct usb_function *f, unsigned intf) +{ + struct f_ecm *ecm = func_to_ecm(f); + + if (intf == ecm->ctrl_id) + return 0; + return ecm->port.in_ep->enabled ? 1 : 0; +} + +static void ecm_disable(struct usb_function *f) +{ + struct f_ecm *ecm = func_to_ecm(f); + struct usb_composite_dev *cdev = f->config->cdev; + + DBG(cdev, "ecm deactivated\n"); + + if (ecm->port.in_ep->enabled) { + gether_disconnect(&ecm->port); + } else { + ecm->port.in_ep->desc = NULL; + ecm->port.out_ep->desc = NULL; + } + + usb_ep_disable(ecm->notify); + ecm->notify->desc = NULL; +} + +/*-------------------------------------------------------------------------*/ + +/* + * Callbacks let us notify the host about connect/disconnect when the + * net device is opened or closed. + * + * For testing, note that link states on this side include both opened + * and closed variants of: + * + * - disconnected/unconfigured + * - configured but inactive (data alt 0) + * - configured and active (data alt 1) + * + * Each needs to be tested with unplug, rmmod, SET_CONFIGURATION, and + * SET_INTERFACE (altsetting). Remember also that "configured" doesn't + * imply the host is actually polling the notification endpoint, and + * likewise that "active" doesn't imply it's actually using the data + * endpoints for traffic. + */ + +static void ecm_open(struct gether *geth) +{ + struct f_ecm *ecm = func_to_ecm(&geth->func); + + DBG(ecm->port.func.config->cdev, "%s\n", __func__); + + ecm->is_open = true; + ecm_notify(ecm); +} + +static void ecm_close(struct gether *geth) +{ + struct f_ecm *ecm = func_to_ecm(&geth->func); + + DBG(ecm->port.func.config->cdev, "%s\n", __func__); + + ecm->is_open = false; + ecm_notify(ecm); +} + +/*-------------------------------------------------------------------------*/ + +/* ethernet function driver setup/binding */ + +static int +ecm_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = c->cdev; + struct f_ecm *ecm = func_to_ecm(f); + struct usb_string *us; + int status; + struct usb_ep *ep; + + struct f_ecm_opts *ecm_opts; + + if (!can_support_ecm(cdev->gadget)) + return -EINVAL; + + ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst); + + /* + * in drivers/usb/gadget/configfs.c:configfs_composite_bind() + * configurations are bound in sequence with list_for_each_entry, + * in each configuration its functions are bound in sequence + * with list_for_each_entry, so we assume no race condition + * with regard to ecm_opts->bound access + */ + if (!ecm_opts->bound) { + mutex_lock(&ecm_opts->lock); + gether_set_gadget(ecm_opts->net, cdev->gadget); + status = gether_register_netdev(ecm_opts->net); + mutex_unlock(&ecm_opts->lock); + if (status) + return status; + ecm_opts->bound = true; + } + + ecm_string_defs[1].s = ecm->ethaddr; + + us = usb_gstrings_attach(cdev, ecm_strings, + ARRAY_SIZE(ecm_string_defs)); + if (IS_ERR(us)) + return PTR_ERR(us); + ecm_control_intf.iInterface = us[0].id; + ecm_data_intf.iInterface = us[2].id; + ecm_desc.iMACAddress = us[1].id; + ecm_iad_descriptor.iFunction = us[3].id; + + /* allocate instance-specific interface IDs */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + ecm->ctrl_id = status; + ecm_iad_descriptor.bFirstInterface = status; + + ecm_control_intf.bInterfaceNumber = status; + ecm_union_desc.bMasterInterface0 = status; + + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + ecm->data_id = status; + + ecm_data_nop_intf.bInterfaceNumber = status; + ecm_data_intf.bInterfaceNumber = status; + ecm_union_desc.bSlaveInterface0 = status; + + status = -ENODEV; + + /* allocate instance-specific endpoints */ + ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_in_desc); + if (!ep) + goto fail; + ecm->port.in_ep = ep; + + ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_out_desc); + if (!ep) + goto fail; + ecm->port.out_ep = ep; + + /* NOTE: a status/notification endpoint is *OPTIONAL* but we + * don't treat it that way. It's simpler, and some newer CDC + * profiles (wireless handsets) no longer treat it as optional. + */ + ep = usb_ep_autoconfig(cdev->gadget, &fs_ecm_notify_desc); + if (!ep) + goto fail; + ecm->notify = ep; + + status = -ENOMEM; + + /* allocate notification request and buffer */ + ecm->notify_req = usb_ep_alloc_request(ep, GFP_KERNEL); + if (!ecm->notify_req) + goto fail; + ecm->notify_req->buf = kmalloc(ECM_STATUS_BYTECOUNT, GFP_KERNEL); + if (!ecm->notify_req->buf) + goto fail; + ecm->notify_req->context = ecm; + ecm->notify_req->complete = ecm_notify_complete; + + /* support all relevant hardware speeds... we expect that when + * hardware is dual speed, all bulk-capable endpoints work at + * both speeds + */ + hs_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress; + hs_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress; + hs_ecm_notify_desc.bEndpointAddress = + fs_ecm_notify_desc.bEndpointAddress; + + ss_ecm_in_desc.bEndpointAddress = fs_ecm_in_desc.bEndpointAddress; + ss_ecm_out_desc.bEndpointAddress = fs_ecm_out_desc.bEndpointAddress; + ss_ecm_notify_desc.bEndpointAddress = + fs_ecm_notify_desc.bEndpointAddress; + + status = usb_assign_descriptors(f, ecm_fs_function, ecm_hs_function, + ecm_ss_function, ecm_ss_function); + if (status) + goto fail; + + /* NOTE: all that is done without knowing or caring about + * the network link ... which is unavailable to this code + * until we're activated via set_alt(). + */ + + ecm->port.open = ecm_open; + ecm->port.close = ecm_close; + + DBG(cdev, "CDC Ethernet: %s speed IN/%s OUT/%s NOTIFY/%s\n", + gadget_is_superspeed(c->cdev->gadget) ? "super" : + gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", + ecm->port.in_ep->name, ecm->port.out_ep->name, + ecm->notify->name); + return 0; + +fail: + if (ecm->notify_req) { + kfree(ecm->notify_req->buf); + usb_ep_free_request(ecm->notify, ecm->notify_req); + } + + ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); + + return status; +} + +static inline struct f_ecm_opts *to_f_ecm_opts(struct config_item *item) +{ + return container_of(to_config_group(item), struct f_ecm_opts, + func_inst.group); +} + +/* f_ecm_item_ops */ +USB_ETHERNET_CONFIGFS_ITEM(ecm); + +/* f_ecm_opts_dev_addr */ +USB_ETHERNET_CONFIGFS_ITEM_ATTR_DEV_ADDR(ecm); + +/* f_ecm_opts_host_addr */ +USB_ETHERNET_CONFIGFS_ITEM_ATTR_HOST_ADDR(ecm); + +/* f_ecm_opts_qmult */ +USB_ETHERNET_CONFIGFS_ITEM_ATTR_QMULT(ecm); + +/* f_ecm_opts_ifname */ +USB_ETHERNET_CONFIGFS_ITEM_ATTR_IFNAME(ecm); + +static struct configfs_attribute *ecm_attrs[] = { + &ecm_opts_attr_dev_addr, + &ecm_opts_attr_host_addr, + &ecm_opts_attr_qmult, + &ecm_opts_attr_ifname, + NULL, +}; + +static const struct config_item_type ecm_func_type = { + .ct_item_ops = &ecm_item_ops, + .ct_attrs = ecm_attrs, + .ct_owner = THIS_MODULE, +}; + +static void ecm_free_inst(struct usb_function_instance *f) +{ + struct f_ecm_opts *opts; + + opts = container_of(f, struct f_ecm_opts, func_inst); + if (opts->bound) + gether_cleanup(netdev_priv(opts->net)); + else + free_netdev(opts->net); + kfree(opts); +} + +static struct usb_function_instance *ecm_alloc_inst(void) +{ + struct f_ecm_opts *opts; + + opts = kzalloc(sizeof(*opts), GFP_KERNEL); + if (!opts) + return ERR_PTR(-ENOMEM); + mutex_init(&opts->lock); + opts->func_inst.free_func_inst = ecm_free_inst; + opts->net = gether_setup_default(); + if (IS_ERR(opts->net)) { + struct net_device *net = opts->net; + kfree(opts); + return ERR_CAST(net); + } + + config_group_init_type_name(&opts->func_inst.group, "", &ecm_func_type); + + return &opts->func_inst; +} + +static void ecm_free(struct usb_function *f) +{ + struct f_ecm *ecm; + struct f_ecm_opts *opts; + + ecm = func_to_ecm(f); + opts = container_of(f->fi, struct f_ecm_opts, func_inst); + kfree(ecm); + mutex_lock(&opts->lock); + opts->refcnt--; + mutex_unlock(&opts->lock); +} + +static void ecm_unbind(struct usb_configuration *c, struct usb_function *f) +{ + struct f_ecm *ecm = func_to_ecm(f); + + DBG(c->cdev, "ecm unbind\n"); + + usb_free_all_descriptors(f); + + if (atomic_read(&ecm->notify_count)) { + usb_ep_dequeue(ecm->notify, ecm->notify_req); + atomic_set(&ecm->notify_count, 0); + } + + kfree(ecm->notify_req->buf); + usb_ep_free_request(ecm->notify, ecm->notify_req); +} + +static struct usb_function *ecm_alloc(struct usb_function_instance *fi) +{ + struct f_ecm *ecm; + struct f_ecm_opts *opts; + int status; + + /* allocate and initialize one new instance */ + ecm = kzalloc(sizeof(*ecm), GFP_KERNEL); + if (!ecm) + return ERR_PTR(-ENOMEM); + + opts = container_of(fi, struct f_ecm_opts, func_inst); + mutex_lock(&opts->lock); + opts->refcnt++; + + /* export host's Ethernet address in CDC format */ + status = gether_get_host_addr_cdc(opts->net, ecm->ethaddr, + sizeof(ecm->ethaddr)); + if (status < 12) { + kfree(ecm); + mutex_unlock(&opts->lock); + return ERR_PTR(-EINVAL); + } + + ecm->port.ioport = netdev_priv(opts->net); + mutex_unlock(&opts->lock); + ecm->port.cdc_filter = DEFAULT_FILTER; + + ecm->port.func.name = "cdc_ethernet"; + /* descriptors are per-instance copies */ + ecm->port.func.bind = ecm_bind; + ecm->port.func.unbind = ecm_unbind; + ecm->port.func.set_alt = ecm_set_alt; + ecm->port.func.get_alt = ecm_get_alt; + ecm->port.func.setup = ecm_setup; + ecm->port.func.disable = ecm_disable; + ecm->port.func.free_func = ecm_free; + + return &ecm->port.func; +} + +DECLARE_USB_FUNCTION_INIT(ecm, ecm_alloc_inst, ecm_alloc); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("David Brownell"); |