linux/drivers/usb/gadget/f_subset.c
Sebastian Andrzej Siewior 1616e99d42 usb: gadget: let f_* use usb_string_ids_tab() where it makes sense
Instead of calling usb_string_id() multiple times I replace it with one
usb_string_ids_tab(). The NULL pointer in struct usb_string with "" and
are not overwritten in fail or unbind case.

The conditional assignment remains because some gadgets recycle the string
ID because the same descriptor (and string ID) is used if we have more
than one config descriptor.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2012-10-31 15:11:47 +02:00

423 lines
13 KiB
C

/*
* 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.
*/
#include <linux/slab.h>
#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 f_gether {
struct gether port;
char ethaddr[14];
};
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 = {
.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 mdlm_header_desc = {
.bLength = sizeof mdlm_header_desc,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_HEADER_TYPE,
.bcdCDC = cpu_to_le16(0x0110),
};
static struct usb_cdc_mdlm_desc mdlm_desc = {
.bLength = sizeof mdlm_desc,
.bDescriptorType = USB_DT_CS_INTERFACE,
.bDescriptorSubType = USB_CDC_MDLM_TYPE,
.bcdVersion = 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[] = {
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 = {
.bLength = sizeof ether_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,
};
/* full speed support: */
static struct usb_endpoint_descriptor fs_subset_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_subset_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 *fs_eth_function[] = {
(struct usb_descriptor_header *) &subset_data_intf,
(struct usb_descriptor_header *) &mdlm_header_desc,
(struct usb_descriptor_header *) &mdlm_desc,
(struct usb_descriptor_header *) &mdlm_detail_desc,
(struct usb_descriptor_header *) &ether_desc,
(struct usb_descriptor_header *) &fs_subset_in_desc,
(struct usb_descriptor_header *) &fs_subset_out_desc,
NULL,
};
/* high speed support: */
static struct usb_endpoint_descriptor hs_subset_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 hs_subset_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 *hs_eth_function[] = {
(struct usb_descriptor_header *) &subset_data_intf,
(struct usb_descriptor_header *) &mdlm_header_desc,
(struct usb_descriptor_header *) &mdlm_desc,
(struct usb_descriptor_header *) &mdlm_detail_desc,
(struct usb_descriptor_header *) &ether_desc,
(struct usb_descriptor_header *) &hs_subset_in_desc,
(struct usb_descriptor_header *) &hs_subset_out_desc,
NULL,
};
/* super speed support: */
static struct usb_endpoint_descriptor ss_subset_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 ss_subset_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 ss_subset_bulk_comp_desc = {
.bLength = sizeof ss_subset_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 *ss_eth_function[] = {
(struct usb_descriptor_header *) &subset_data_intf,
(struct usb_descriptor_header *) &mdlm_header_desc,
(struct usb_descriptor_header *) &mdlm_desc,
(struct usb_descriptor_header *) &mdlm_detail_desc,
(struct usb_descriptor_header *) &ether_desc,
(struct usb_descriptor_header *) &ss_subset_in_desc,
(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
(struct usb_descriptor_header *) &ss_subset_out_desc,
(struct usb_descriptor_header *) &ss_subset_bulk_comp_desc,
NULL,
};
/* string descriptors: */
static struct usb_string geth_string_defs[] = {
[0].s = "CDC Ethernet Subset/SAFE",
[1].s = "",
{ } /* 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");
if (config_ep_by_speed(cdev->gadget, f, geth->port.in_ep) ||
config_ep_by_speed(cdev->gadget, f, geth->port.out_ep)) {
geth->port.in_ep->desc = NULL;
geth->port.out_ep->desc = NULL;
return -EINVAL;
}
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
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_subset_in_desc);
if (!ep)
goto fail;
geth->port.in_ep = ep;
ep->driver_data = cdev; /* claim */
ep = usb_ep_autoconfig(cdev->gadget, &fs_subset_out_desc);
if (!ep)
goto fail;
geth->port.out_ep = ep;
ep->driver_data = cdev; /* claim */
/* support all relevant hardware speeds... we expect that when
* hardware is dual speed, all bulk-capable endpoints work at
* both speeds
*/
hs_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
hs_subset_out_desc.bEndpointAddress =
fs_subset_out_desc.bEndpointAddress;
ss_subset_in_desc.bEndpointAddress = fs_subset_in_desc.bEndpointAddress;
ss_subset_out_desc.bEndpointAddress =
fs_subset_out_desc.bEndpointAddress;
status = usb_assign_descriptors(f, fs_eth_function, hs_eth_function,
ss_eth_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().
*/
DBG(cdev, "CDC Subset: %s speed IN/%s OUT/%s\n",
gadget_is_superspeed(c->cdev->gadget) ? "super" :
gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
geth->port.in_ep->name, geth->port.out_ep->name);
return 0;
fail:
usb_free_all_descriptors(f);
/* we might as well release our claims on endpoints */
if (geth->port.out_ep)
geth->port.out_ep->driver_data = NULL;
if (geth->port.in_ep)
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)
{
geth_string_defs[0].id = 0;
usb_free_all_descriptors(f);
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 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) {
status = usb_string_ids_tab(c->cdev, geth_string_defs);
if (status < 0)
return status;
subset_data_intf.iInterface = geth_string_defs[0].id;
ether_desc.iMACAddress = geth_string_defs[1].id;
}
/* 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, "%pm", ethaddr);
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)
kfree(geth);
return status;
}