diff options
Diffstat (limited to 'drivers/usb/gadget/f_subset.c')
| -rw-r--r-- | drivers/usb/gadget/f_subset.c | 423 |
1 files changed, 423 insertions, 0 deletions
diff --git a/drivers/usb/gadget/f_subset.c b/drivers/usb/gadget/f_subset.c new file mode 100644 index 000000000000..afeab9a0523f --- /dev/null +++ b/drivers/usb/gadget/f_subset.c @@ -0,0 +1,423 @@ +/* + * f_subset.c -- "CDC Subset" Ethernet link function driver + * + * Copyright (C) 2003-2005,2008 David Brownell + * Copyright (C) 2008 Nokia Corporation + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/etherdevice.h> + +#include "u_ether.h" + + +/* + * This function packages a simple "CDC Subset" Ethernet port with no real + * control mechanisms; just raw data transfer over two bulk endpoints. + * The data transfer model is exactly that of CDC Ethernet, which is + * why we call it the "CDC Subset". + * + * Because it's not standardized, this has some interoperability issues. + * They mostly relate to driver binding, since the data transfer model is + * so simple (CDC Ethernet). The original versions of this protocol used + * specific product/vendor IDs: byteswapped IDs for Digital Equipment's + * SA-1100 "Itsy" board, which could run Linux 2.4 kernels and supported + * daughtercards with USB peripheral connectors. (It was used more often + * with other boards, using the Itsy identifiers.) Linux hosts recognized + * this with CONFIG_USB_ARMLINUX; these devices have only one configuration + * and one interface. + * + * At some point, MCCI defined a (nonconformant) CDC MDLM variant called + * "SAFE", which happens to have a mode which is identical to the "CDC + * Subset" in terms of data transfer and lack of control model. This was + * adopted by later Sharp Zaurus models, and by some other software which + * Linux hosts recognize with CONFIG_USB_NET_ZAURUS. + * + * Because Microsoft's RNDIS drivers are far from robust, we added a few + * descriptors to the CDC Subset code, making this code look like a SAFE + * implementation. This lets you use MCCI's host side MS-Windows drivers + * if you get fed up with RNDIS. It also makes it easier for composite + * drivers to work, since they can use class based binding instead of + * caring about specific product and vendor IDs. + */ + +struct geth_descs { + struct usb_endpoint_descriptor *in; + struct usb_endpoint_descriptor *out; +}; + +struct f_gether { + struct gether port; + + char ethaddr[14]; + + struct usb_descriptor_header **fs_function; + struct geth_descs fs; + struct usb_descriptor_header **hs_function; + struct geth_descs hs; +}; + +static inline struct f_gether *func_to_geth(struct usb_function *f) +{ + return container_of(f, struct f_gether, port.func); +} + +/*-------------------------------------------------------------------------*/ + +/* + * "Simple" CDC-subset option is a simple vendor-neutral model that most + * full speed controllers can handle: one interface, two bulk endpoints. + * To assist host side drivers, we fancy it up a bit, and add descriptors so + * some host side drivers will understand it as a "SAFE" variant. + * + * "SAFE" loosely follows CDC WMC MDLM, violating the spec in various ways. + * Data endpoints live in the control interface, there's no data interface. + * And it's not used to talk to a cell phone radio. + */ + +/* interface descriptor: */ + +static struct usb_interface_descriptor subset_data_intf __initdata = { + .bLength = sizeof subset_data_intf, + .bDescriptorType = USB_DT_INTERFACE, + + /* .bInterfaceNumber = DYNAMIC */ + .bAlternateSetting = 0, + .bNumEndpoints = 2, + .bInterfaceClass = USB_CLASS_COMM, + .bInterfaceSubClass = USB_CDC_SUBCLASS_MDLM, + .bInterfaceProtocol = 0, + /* .iInterface = DYNAMIC */ +}; + +static struct usb_cdc_header_desc header_desc __initdata = { + .bLength = sizeof header_desc, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_HEADER_TYPE, + + .bcdCDC = __constant_cpu_to_le16(0x0110), +}; + +static struct usb_cdc_mdlm_desc mdlm_desc __initdata = { + .bLength = sizeof mdlm_desc, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_MDLM_TYPE, + + .bcdVersion = __constant_cpu_to_le16(0x0100), + .bGUID = { + 0x5d, 0x34, 0xcf, 0x66, 0x11, 0x18, 0x11, 0xd6, + 0xa2, 0x1a, 0x00, 0x01, 0x02, 0xca, 0x9a, 0x7f, + }, +}; + +/* since "usb_cdc_mdlm_detail_desc" is a variable length structure, we + * can't really use its struct. All we do here is say that we're using + * the submode of "SAFE" which directly matches the CDC Subset. + */ +static u8 mdlm_detail_desc[] __initdata = { + 6, + USB_DT_CS_INTERFACE, + USB_CDC_MDLM_DETAIL_TYPE, + + 0, /* "SAFE" */ + 0, /* network control capabilities (none) */ + 0, /* network data capabilities ("raw" encapsulation) */ +}; + +static struct usb_cdc_ether_desc ether_desc __initdata = { + .bLength = sizeof ether_desc, + .bDescriptorType = USB_DT_CS_INTERFACE, + .bDescriptorSubType = USB_CDC_ETHERNET_TYPE, + + /* this descriptor actually adds value, surprise! */ + /* .iMACAddress = DYNAMIC */ + .bmEthernetStatistics = __constant_cpu_to_le32(0), /* no statistics */ + .wMaxSegmentSize = __constant_cpu_to_le16(ETH_FRAME_LEN), + .wNumberMCFilters = __constant_cpu_to_le16(0), + .bNumberPowerFilters = 0, +}; + +/* full speed support: */ + +static struct usb_endpoint_descriptor fs_in_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_IN, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_endpoint_descriptor fs_out_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bEndpointAddress = USB_DIR_OUT, + .bmAttributes = USB_ENDPOINT_XFER_BULK, +}; + +static struct usb_descriptor_header *fs_eth_function[] __initdata = { + (struct usb_descriptor_header *) &subset_data_intf, + (struct usb_descriptor_header *) &header_desc, + (struct usb_descriptor_header *) &mdlm_desc, + (struct usb_descriptor_header *) &mdlm_detail_desc, + (struct usb_descriptor_header *) ðer_desc, + (struct usb_descriptor_header *) &fs_in_desc, + (struct usb_descriptor_header *) &fs_out_desc, + NULL, +}; + +/* high speed support: */ + +static struct usb_endpoint_descriptor hs_in_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16(512), +}; + +static struct usb_endpoint_descriptor hs_out_desc __initdata = { + .bLength = USB_DT_ENDPOINT_SIZE, + .bDescriptorType = USB_DT_ENDPOINT, + + .bmAttributes = USB_ENDPOINT_XFER_BULK, + .wMaxPacketSize = __constant_cpu_to_le16(512), +}; + +static struct usb_descriptor_header *hs_eth_function[] __initdata = { + (struct usb_descriptor_header *) &subset_data_intf, + (struct usb_descriptor_header *) &header_desc, + (struct usb_descriptor_header *) &mdlm_desc, + (struct usb_descriptor_header *) &mdlm_detail_desc, + (struct usb_descriptor_header *) ðer_desc, + (struct usb_descriptor_header *) &hs_in_desc, + (struct usb_descriptor_header *) &hs_out_desc, + NULL, +}; + +/* string descriptors: */ + +static struct usb_string geth_string_defs[] = { + [0].s = "CDC Ethernet Subset/SAFE", + [1].s = NULL /* DYNAMIC */, + { } /* end of list */ +}; + +static struct usb_gadget_strings geth_string_table = { + .language = 0x0409, /* en-us */ + .strings = geth_string_defs, +}; + +static struct usb_gadget_strings *geth_strings[] = { + &geth_string_table, + NULL, +}; + +/*-------------------------------------------------------------------------*/ + +static int geth_set_alt(struct usb_function *f, unsigned intf, unsigned alt) +{ + struct f_gether *geth = func_to_geth(f); + struct usb_composite_dev *cdev = f->config->cdev; + struct net_device *net; + + /* we know alt == 0, so this is an activation or a reset */ + + if (geth->port.in_ep->driver_data) { + DBG(cdev, "reset cdc subset\n"); + gether_disconnect(&geth->port); + } + + DBG(cdev, "init + activate cdc subset\n"); + geth->port.in = ep_choose(cdev->gadget, + geth->hs.in, geth->fs.in); + geth->port.out = ep_choose(cdev->gadget, + geth->hs.out, geth->fs.out); + + net = gether_connect(&geth->port); + return IS_ERR(net) ? PTR_ERR(net) : 0; +} + +static void geth_disable(struct usb_function *f) +{ + struct f_gether *geth = func_to_geth(f); + struct usb_composite_dev *cdev = f->config->cdev; + + DBG(cdev, "net deactivated\n"); + gether_disconnect(&geth->port); +} + +/*-------------------------------------------------------------------------*/ + +/* serial function driver setup/binding */ + +static int __init +geth_bind(struct usb_configuration *c, struct usb_function *f) +{ + struct usb_composite_dev *cdev = c->cdev; + struct f_gether *geth = func_to_geth(f); + int status; + struct usb_ep *ep; + + /* allocate instance-specific interface IDs */ + status = usb_interface_id(c, f); + if (status < 0) + goto fail; + subset_data_intf.bInterfaceNumber = status; + + status = -ENODEV; + + /* allocate instance-specific endpoints */ + ep = usb_ep_autoconfig(cdev->gadget, &fs_in_desc); + if (!ep) + goto fail; + geth->port.in_ep = ep; + ep->driver_data = cdev; /* claim */ + + ep = usb_ep_autoconfig(cdev->gadget, &fs_out_desc); + if (!ep) + goto fail; + geth->port.out_ep = ep; + ep->driver_data = cdev; /* claim */ + + /* copy descriptors, and track endpoint copies */ + f->descriptors = usb_copy_descriptors(fs_eth_function); + + geth->fs.in = usb_find_endpoint(fs_eth_function, + f->descriptors, &fs_in_desc); + geth->fs.out = usb_find_endpoint(fs_eth_function, + f->descriptors, &fs_out_desc); + + + /* support all relevant hardware speeds... we expect that when + * hardware is dual speed, all bulk-capable endpoints work at + * both speeds + */ + if (gadget_is_dualspeed(c->cdev->gadget)) { + hs_in_desc.bEndpointAddress = + fs_in_desc.bEndpointAddress; + hs_out_desc.bEndpointAddress = + fs_out_desc.bEndpointAddress; + + /* copy descriptors, and track endpoint copies */ + f->hs_descriptors = usb_copy_descriptors(hs_eth_function); + + geth->hs.in = usb_find_endpoint(hs_eth_function, + f->hs_descriptors, &hs_in_desc); + geth->hs.out = usb_find_endpoint(hs_eth_function, + f->hs_descriptors, &hs_out_desc); + } + + /* 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(). + */ + + DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n", + gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full", + geth->port.in_ep->name, geth->port.out_ep->name); + return 0; + +fail: + /* we might as well release our claims on endpoints */ + if (geth->port.out) + geth->port.out_ep->driver_data = NULL; + if (geth->port.in) + geth->port.in_ep->driver_data = NULL; + + ERROR(cdev, "%s: can't bind, err %d\n", f->name, status); + + return status; +} + +static void +geth_unbind(struct usb_configuration *c, struct usb_function *f) +{ + if (gadget_is_dualspeed(c->cdev->gadget)) + usb_free_descriptors(f->hs_descriptors); + usb_free_descriptors(f->descriptors); + geth_string_defs[1].s = NULL; + kfree(func_to_geth(f)); +} + +/** + * geth_bind_config - add CDC Subset network link to a configuration + * @c: the configuration to support the network link + * @ethaddr: a buffer in which the ethernet address of the host side + * side of the link was recorded + * Context: single threaded during gadget setup + * + * Returns zero on success, else negative errno. + * + * Caller must have called @gether_setup(). Caller is also responsible + * for calling @gether_cleanup() before module unload. + */ +int __init geth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]) +{ + struct f_gether *geth; + int status; + + if (!ethaddr) + return -EINVAL; + + /* maybe allocate device-global string IDs */ + if (geth_string_defs[0].id == 0) { + + /* interface label */ + status = usb_string_id(c->cdev); + if (status < 0) + return status; + geth_string_defs[0].id = status; + subset_data_intf.iInterface = status; + + /* MAC address */ + status = usb_string_id(c->cdev); + if (status < 0) + return status; + geth_string_defs[1].id = status; + ether_desc.iMACAddress = status; + } + + /* allocate and initialize one new instance */ + geth = kzalloc(sizeof *geth, GFP_KERNEL); + if (!geth) + return -ENOMEM; + + /* export host's Ethernet address in CDC format */ + snprintf(geth->ethaddr, sizeof geth->ethaddr, + "%02X%02X%02X%02X%02X%02X", + ethaddr[0], ethaddr[1], ethaddr[2], + ethaddr[3], ethaddr[4], ethaddr[5]); + geth_string_defs[1].s = geth->ethaddr; + + geth->port.cdc_filter = DEFAULT_FILTER; + + geth->port.func.name = "cdc_subset"; + geth->port.func.strings = geth_strings; + geth->port.func.bind = geth_bind; + geth->port.func.unbind = geth_unbind; + geth->port.func.set_alt = geth_set_alt; + geth->port.func.disable = geth_disable; + + status = usb_add_function(c, &geth->port.func); + if (status) { + geth_string_defs[1].s = NULL; + kfree(geth); + } + return status; +} |