/drivers/usb/gadget/g_ffs.c

  1/*
  2 * g_ffs.c -- user mode file system API for USB composite function controllers
  3 *
  4 * Copyright (C) 2010 Samsung Electronics
  5 * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
  6 *
  7 * This program is free software; you can redistribute it and/or modify
  8 * it under the terms of the GNU General Public License as published by
  9 * the Free Software Foundation; either version 2 of the License, or
 10 * (at your option) any later version.
 11 *
 12 * This program is distributed in the hope that it will be useful,
 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15 * GNU General Public License for more details.
 16 *
 17 * You should have received a copy of the GNU General Public License
 18 * along with this program; if not, write to the Free Software
 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 20 */
 21
 22#define pr_fmt(fmt) "g_ffs: " fmt
 23
 24#include <linux/module.h>
 25#include <linux/utsname.h>
 26
 27/*
 28 * kbuild is not very cooperative with respect to linking separately
 29 * compiled library objects into one module.  So for now we won't use
 30 * separate compilation ... ensuring init/exit sections work to shrink
 31 * the runtime footprint, and giving us at least some parts of what
 32 * a "gcc --combine ... part1.c part2.c part3.c ... " build would.
 33 */
 34
 35#include "composite.c"
 36#include "usbstring.c"
 37#include "config.c"
 38#include "epautoconf.c"
 39
 40#if defined CONFIG_USB_FUNCTIONFS_ETH || defined CONFIG_USB_FUNCTIONFS_RNDIS
 41#  if defined USB_ETH_RNDIS
 42#    undef USB_ETH_RNDIS
 43#  endif
 44#  ifdef CONFIG_USB_FUNCTIONFS_RNDIS
 45#    define USB_ETH_RNDIS y
 46#  endif
 47
 48#  include "f_ecm.c"
 49#  include "f_subset.c"
 50#  ifdef USB_ETH_RNDIS
 51#    include "f_rndis.c"
 52#    include "rndis.c"
 53#  endif
 54#  include "u_ether.c"
 55
 56static u8 gfs_hostaddr[ETH_ALEN];
 57#  ifdef CONFIG_USB_FUNCTIONFS_ETH
 58static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN]);
 59#  endif
 60#else
 61#  define gether_cleanup() do { } while (0)
 62#  define gether_setup(gadget, hostaddr)   ((int)0)
 63#  define gfs_hostaddr NULL
 64#endif
 65
 66#include "f_fs.c"
 67
 68#define DRIVER_NAME	"g_ffs"
 69#define DRIVER_DESC	"USB Function Filesystem"
 70#define DRIVER_VERSION	"24 Aug 2004"
 71
 72MODULE_DESCRIPTION(DRIVER_DESC);
 73MODULE_AUTHOR("Michal Nazarewicz");
 74MODULE_LICENSE("GPL");
 75
 76#define GFS_VENDOR_ID	0x1d6b	/* Linux Foundation */
 77#define GFS_PRODUCT_ID	0x0105	/* FunctionFS Gadget */
 78
 79static struct usb_device_descriptor gfs_dev_desc = {
 80	.bLength		= sizeof gfs_dev_desc,
 81	.bDescriptorType	= USB_DT_DEVICE,
 82
 83	.bcdUSB			= cpu_to_le16(0x0200),
 84	.bDeviceClass		= USB_CLASS_PER_INTERFACE,
 85
 86	.idVendor		= cpu_to_le16(GFS_VENDOR_ID),
 87	.idProduct		= cpu_to_le16(GFS_PRODUCT_ID),
 88};
 89
 90module_param_named(bDeviceClass,    gfs_dev_desc.bDeviceClass,    byte,   0644);
 91MODULE_PARM_DESC(bDeviceClass, "USB Device class");
 92module_param_named(bDeviceSubClass, gfs_dev_desc.bDeviceSubClass, byte,   0644);
 93MODULE_PARM_DESC(bDeviceSubClass, "USB Device subclass");
 94module_param_named(bDeviceProtocol, gfs_dev_desc.bDeviceProtocol, byte,   0644);
 95MODULE_PARM_DESC(bDeviceProtocol, "USB Device protocol");
 96
 97static const struct usb_descriptor_header *gfs_otg_desc[] = {
 98	(const struct usb_descriptor_header *)
 99	&(const struct usb_otg_descriptor) {
100		.bLength		= sizeof(struct usb_otg_descriptor),
101		.bDescriptorType	= USB_DT_OTG,
102
103		/*
104		 * REVISIT SRP-only hardware is possible, although
105		 * it would not be called "OTG" ...
106		 */
107		.bmAttributes		= USB_OTG_SRP | USB_OTG_HNP,
108	},
109
110	NULL
111};
112
113/* String IDs are assigned dynamically */
114static struct usb_string gfs_strings[] = {
115#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
116	{ .s = "FunctionFS + RNDIS" },
117#endif
118#ifdef CONFIG_USB_FUNCTIONFS_ETH
119	{ .s = "FunctionFS + ECM" },
120#endif
121#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
122	{ .s = "FunctionFS" },
123#endif
124	{  } /* end of list */
125};
126
127static struct usb_gadget_strings *gfs_dev_strings[] = {
128	&(struct usb_gadget_strings) {
129		.language	= 0x0409,	/* en-us */
130		.strings	= gfs_strings,
131	},
132	NULL,
133};
134
135struct gfs_configuration {
136	struct usb_configuration c;
137	int (*eth)(struct usb_configuration *c, u8 *ethaddr);
138} gfs_configurations[] = {
139#ifdef CONFIG_USB_FUNCTIONFS_RNDIS
140	{
141		.eth		= rndis_bind_config,
142	},
143#endif
144
145#ifdef CONFIG_USB_FUNCTIONFS_ETH
146	{
147		.eth		= eth_bind_config,
148	},
149#endif
150
151#ifdef CONFIG_USB_FUNCTIONFS_GENERIC
152	{
153	},
154#endif
155};
156
157static int gfs_bind(struct usb_composite_dev *cdev);
158static int gfs_unbind(struct usb_composite_dev *cdev);
159static int gfs_do_config(struct usb_configuration *c);
160
161static struct usb_composite_driver gfs_driver = {
162	.name		= DRIVER_NAME,
163	.dev		= &gfs_dev_desc,
164	.strings	= gfs_dev_strings,
165	.max_speed	= USB_SPEED_HIGH,
166	.unbind		= gfs_unbind,
167	.iProduct	= DRIVER_DESC,
168};
169
170static struct ffs_data *gfs_ffs_data;
171static unsigned long gfs_registered;
172
173static int  gfs_init(void)
174{
175	ENTER();
176
177	return functionfs_init();
178}
179module_init(gfs_init);
180
181static void  gfs_exit(void)
182{
183	ENTER();
184
185	if (test_and_clear_bit(0, &gfs_registered))
186		usb_composite_unregister(&gfs_driver);
187
188	functionfs_cleanup();
189}
190module_exit(gfs_exit);
191
192static int functionfs_ready_callback(struct ffs_data *ffs)
193{
194	int ret;
195
196	ENTER();
197
198	if (WARN_ON(test_and_set_bit(0, &gfs_registered)))
199		return -EBUSY;
200
201	gfs_ffs_data = ffs;
202	ret = usb_composite_probe(&gfs_driver, gfs_bind);
203	if (unlikely(ret < 0))
204		clear_bit(0, &gfs_registered);
205	return ret;
206}
207
208static void functionfs_closed_callback(struct ffs_data *ffs)
209{
210	ENTER();
211
212	if (test_and_clear_bit(0, &gfs_registered))
213		usb_composite_unregister(&gfs_driver);
214}
215
216static int functionfs_check_dev_callback(const char *dev_name)
217{
218	return 0;
219}
220
221static int gfs_bind(struct usb_composite_dev *cdev)
222{
223	int ret, i;
224
225	ENTER();
226
227	if (WARN_ON(!gfs_ffs_data))
228		return -ENODEV;
229
230	ret = gether_setup(cdev->gadget, gfs_hostaddr);
231	if (unlikely(ret < 0))
232		goto error_quick;
233
234	ret = usb_string_ids_tab(cdev, gfs_strings);
235	if (unlikely(ret < 0))
236		goto error;
237
238	ret = functionfs_bind(gfs_ffs_data, cdev);
239	if (unlikely(ret < 0))
240		goto error;
241
242	for (i = 0; i < ARRAY_SIZE(gfs_configurations); ++i) {
243		struct gfs_configuration *c = gfs_configurations + i;
244
245		c->c.label			= gfs_strings[i].s;
246		c->c.iConfiguration		= gfs_strings[i].id;
247		c->c.bConfigurationValue	= 1 + i;
248		c->c.bmAttributes		= USB_CONFIG_ATT_SELFPOWER;
249
250		ret = usb_add_config(cdev, &c->c, gfs_do_config);
251		if (unlikely(ret < 0))
252			goto error_unbind;
253	}
254
255	return 0;
256
257error_unbind:
258	functionfs_unbind(gfs_ffs_data);
259error:
260	gether_cleanup();
261error_quick:
262	gfs_ffs_data = NULL;
263	return ret;
264}
265
266static int gfs_unbind(struct usb_composite_dev *cdev)
267{
268	ENTER();
269
270	/*
271	 * We may have been called in an error recovery from
272	 * composite_bind() after gfs_unbind() failure so we need to
273	 * check if gfs_ffs_data is not NULL since gfs_bind() handles
274	 * all error recovery itself.  I'd rather we werent called
275	 * from composite on orror recovery, but what you're gonna
276	 * do...?
277	 */
278	if (gfs_ffs_data) {
279		gether_cleanup();
280		functionfs_unbind(gfs_ffs_data);
281		gfs_ffs_data = NULL;
282	}
283
284	return 0;
285}
286
287static int gfs_do_config(struct usb_configuration *c)
288{
289	struct gfs_configuration *gc =
290		container_of(c, struct gfs_configuration, c);
291	int ret;
292
293	if (WARN_ON(!gfs_ffs_data))
294		return -ENODEV;
295
296	if (gadget_is_otg(c->cdev->gadget)) {
297		c->descriptors = gfs_otg_desc;
298		c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
299	}
300
301	if (gc->eth) {
302		ret = gc->eth(c, gfs_hostaddr);
303		if (unlikely(ret < 0))
304			return ret;
305	}
306
307	ret = functionfs_bind_config(c->cdev, c, gfs_ffs_data);
308	if (unlikely(ret < 0))
309		return ret;
310
311	/*
312	 * After previous do_configs there may be some invalid
313	 * pointers in c->interface array.  This happens every time
314	 * a user space function with fewer interfaces than a user
315	 * space function that was run before the new one is run.  The
316	 * compasit's set_config() assumes that if there is no more
317	 * then MAX_CONFIG_INTERFACES interfaces in a configuration
318	 * then there is a NULL pointer after the last interface in
319	 * c->interface array.  We need to make sure this is true.
320	 */
321	if (c->next_interface_id < ARRAY_SIZE(c->interface))
322		c->interface[c->next_interface_id] = NULL;
323
324	return 0;
325}
326
327#ifdef CONFIG_USB_FUNCTIONFS_ETH
328
329static int eth_bind_config(struct usb_configuration *c, u8 ethaddr[ETH_ALEN])
330{
331	return can_support_ecm(c->cdev->gadget)
332		? ecm_bind_config(c, ethaddr)
333		: geth_bind_config(c, ethaddr);
334}
335
336#endif