blob: 490b00b01a7d68774263c4d84c89b7775eb4acad [file] [log] [blame]
David Brownell61d8bae2008-06-19 18:18:50 -07001/*
2 * f_serial.c - generic USB serial function driver
3 *
4 * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com)
5 * Copyright (C) 2008 by David Brownell
6 * Copyright (C) 2008 by Nokia Corporation
7 *
8 * This software is distributed under the terms of the GNU General
9 * Public License ("GPL") as published by the Free Software Foundation,
10 * either version 2 of that License or (at your option) any later version.
11 */
12
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090013#include <linux/slab.h>
David Brownell61d8bae2008-06-19 18:18:50 -070014#include <linux/kernel.h>
15#include <linux/device.h>
16
17#include "u_serial.h"
18#include "gadget_chips.h"
19
20
21/*
22 * This function packages a simple "generic serial" port with no real
23 * control mechanisms, just raw data transfer over two bulk endpoints.
24 *
25 * Because it's not standardized, this isn't as interoperable as the
26 * CDC ACM driver. However, for many purposes it's just as functional
27 * if you can arrange appropriate host side drivers.
28 */
29
30struct gser_descs {
31 struct usb_endpoint_descriptor *in;
32 struct usb_endpoint_descriptor *out;
33};
34
35struct f_gser {
36 struct gserial port;
37 u8 data_id;
38 u8 port_num;
39
David Brownell61d8bae2008-06-19 18:18:50 -070040 struct gser_descs fs;
David Brownell61d8bae2008-06-19 18:18:50 -070041 struct gser_descs hs;
42};
43
44static inline struct f_gser *func_to_gser(struct usb_function *f)
45{
46 return container_of(f, struct f_gser, port.func);
47}
48
49/*-------------------------------------------------------------------------*/
50
51/* interface descriptor: */
52
53static struct usb_interface_descriptor gser_interface_desc __initdata = {
54 .bLength = USB_DT_INTERFACE_SIZE,
55 .bDescriptorType = USB_DT_INTERFACE,
56 /* .bInterfaceNumber = DYNAMIC */
57 .bNumEndpoints = 2,
58 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
59 .bInterfaceSubClass = 0,
60 .bInterfaceProtocol = 0,
61 /* .iInterface = DYNAMIC */
62};
63
64/* full speed support: */
65
66static struct usb_endpoint_descriptor gser_fs_in_desc __initdata = {
67 .bLength = USB_DT_ENDPOINT_SIZE,
68 .bDescriptorType = USB_DT_ENDPOINT,
69 .bEndpointAddress = USB_DIR_IN,
70 .bmAttributes = USB_ENDPOINT_XFER_BULK,
71};
72
73static struct usb_endpoint_descriptor gser_fs_out_desc __initdata = {
74 .bLength = USB_DT_ENDPOINT_SIZE,
75 .bDescriptorType = USB_DT_ENDPOINT,
76 .bEndpointAddress = USB_DIR_OUT,
77 .bmAttributes = USB_ENDPOINT_XFER_BULK,
78};
79
80static struct usb_descriptor_header *gser_fs_function[] __initdata = {
81 (struct usb_descriptor_header *) &gser_interface_desc,
82 (struct usb_descriptor_header *) &gser_fs_in_desc,
83 (struct usb_descriptor_header *) &gser_fs_out_desc,
84 NULL,
85};
86
87/* high speed support: */
88
89static struct usb_endpoint_descriptor gser_hs_in_desc __initdata = {
90 .bLength = USB_DT_ENDPOINT_SIZE,
91 .bDescriptorType = USB_DT_ENDPOINT,
92 .bmAttributes = USB_ENDPOINT_XFER_BULK,
Harvey Harrison551509d2009-02-11 14:11:36 -080093 .wMaxPacketSize = cpu_to_le16(512),
David Brownell61d8bae2008-06-19 18:18:50 -070094};
95
96static struct usb_endpoint_descriptor gser_hs_out_desc __initdata = {
97 .bLength = USB_DT_ENDPOINT_SIZE,
98 .bDescriptorType = USB_DT_ENDPOINT,
99 .bmAttributes = USB_ENDPOINT_XFER_BULK,
Harvey Harrison551509d2009-02-11 14:11:36 -0800100 .wMaxPacketSize = cpu_to_le16(512),
David Brownell61d8bae2008-06-19 18:18:50 -0700101};
102
103static struct usb_descriptor_header *gser_hs_function[] __initdata = {
104 (struct usb_descriptor_header *) &gser_interface_desc,
105 (struct usb_descriptor_header *) &gser_hs_in_desc,
106 (struct usb_descriptor_header *) &gser_hs_out_desc,
107 NULL,
108};
109
110/* string descriptors: */
111
112static struct usb_string gser_string_defs[] = {
113 [0].s = "Generic Serial",
114 { } /* end of list */
115};
116
117static struct usb_gadget_strings gser_string_table = {
118 .language = 0x0409, /* en-us */
119 .strings = gser_string_defs,
120};
121
122static struct usb_gadget_strings *gser_strings[] = {
123 &gser_string_table,
124 NULL,
125};
126
127/*-------------------------------------------------------------------------*/
128
129static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
130{
131 struct f_gser *gser = func_to_gser(f);
132 struct usb_composite_dev *cdev = f->config->cdev;
133
134 /* we know alt == 0, so this is an activation or a reset */
135
136 if (gser->port.in->driver_data) {
137 DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
138 gserial_disconnect(&gser->port);
139 } else {
140 DBG(cdev, "activate generic ttyGS%d\n", gser->port_num);
141 gser->port.in_desc = ep_choose(cdev->gadget,
142 gser->hs.in, gser->fs.in);
143 gser->port.out_desc = ep_choose(cdev->gadget,
144 gser->hs.out, gser->fs.out);
145 }
146 gserial_connect(&gser->port, gser->port_num);
147 return 0;
148}
149
150static void gser_disable(struct usb_function *f)
151{
152 struct f_gser *gser = func_to_gser(f);
153 struct usb_composite_dev *cdev = f->config->cdev;
154
155 DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num);
156 gserial_disconnect(&gser->port);
157}
158
159/*-------------------------------------------------------------------------*/
160
161/* serial function driver setup/binding */
162
163static int __init
164gser_bind(struct usb_configuration *c, struct usb_function *f)
165{
166 struct usb_composite_dev *cdev = c->cdev;
167 struct f_gser *gser = func_to_gser(f);
168 int status;
169 struct usb_ep *ep;
170
171 /* allocate instance-specific interface IDs */
172 status = usb_interface_id(c, f);
173 if (status < 0)
174 goto fail;
175 gser->data_id = status;
176 gser_interface_desc.bInterfaceNumber = status;
177
178 status = -ENODEV;
179
180 /* allocate instance-specific endpoints */
181 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
182 if (!ep)
183 goto fail;
184 gser->port.in = ep;
185 ep->driver_data = cdev; /* claim */
186
187 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
188 if (!ep)
189 goto fail;
190 gser->port.out = ep;
191 ep->driver_data = cdev; /* claim */
192
193 /* copy descriptors, and track endpoint copies */
194 f->descriptors = usb_copy_descriptors(gser_fs_function);
195
196 gser->fs.in = usb_find_endpoint(gser_fs_function,
197 f->descriptors, &gser_fs_in_desc);
198 gser->fs.out = usb_find_endpoint(gser_fs_function,
199 f->descriptors, &gser_fs_out_desc);
200
201
202 /* support all relevant hardware speeds... we expect that when
203 * hardware is dual speed, all bulk-capable endpoints work at
204 * both speeds
205 */
206 if (gadget_is_dualspeed(c->cdev->gadget)) {
207 gser_hs_in_desc.bEndpointAddress =
208 gser_fs_in_desc.bEndpointAddress;
209 gser_hs_out_desc.bEndpointAddress =
210 gser_fs_out_desc.bEndpointAddress;
211
212 /* copy descriptors, and track endpoint copies */
213 f->hs_descriptors = usb_copy_descriptors(gser_hs_function);
214
215 gser->hs.in = usb_find_endpoint(gser_hs_function,
216 f->hs_descriptors, &gser_hs_in_desc);
217 gser->hs.out = usb_find_endpoint(gser_hs_function,
218 f->hs_descriptors, &gser_hs_out_desc);
219 }
220
221 DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
222 gser->port_num,
223 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
224 gser->port.in->name, gser->port.out->name);
225 return 0;
226
227fail:
228 /* we might as well release our claims on endpoints */
229 if (gser->port.out)
230 gser->port.out->driver_data = NULL;
231 if (gser->port.in)
232 gser->port.in->driver_data = NULL;
233
234 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
235
236 return status;
237}
238
239static void
240gser_unbind(struct usb_configuration *c, struct usb_function *f)
241{
242 if (gadget_is_dualspeed(c->cdev->gadget))
243 usb_free_descriptors(f->hs_descriptors);
244 usb_free_descriptors(f->descriptors);
245 kfree(func_to_gser(f));
246}
247
248/**
249 * gser_bind_config - add a generic serial function to a configuration
250 * @c: the configuration to support the serial instance
251 * @port_num: /dev/ttyGS* port this interface will use
252 * Context: single threaded during gadget setup
253 *
254 * Returns zero on success, else negative errno.
255 *
256 * Caller must have called @gserial_setup() with enough ports to
257 * handle all the ones it binds. Caller is also responsible
258 * for calling @gserial_cleanup() before module unload.
259 */
260int __init gser_bind_config(struct usb_configuration *c, u8 port_num)
261{
262 struct f_gser *gser;
263 int status;
264
265 /* REVISIT might want instance-specific strings to help
266 * distinguish instances ...
267 */
268
269 /* maybe allocate device-global string ID */
270 if (gser_string_defs[0].id == 0) {
271 status = usb_string_id(c->cdev);
272 if (status < 0)
273 return status;
274 gser_string_defs[0].id = status;
275 }
276
277 /* allocate and initialize one new instance */
278 gser = kzalloc(sizeof *gser, GFP_KERNEL);
279 if (!gser)
280 return -ENOMEM;
281
282 gser->port_num = port_num;
283
284 gser->port.func.name = "gser";
285 gser->port.func.strings = gser_strings;
286 gser->port.func.bind = gser_bind;
287 gser->port.func.unbind = gser_unbind;
288 gser->port.func.set_alt = gser_set_alt;
289 gser->port.func.disable = gser_disable;
290
291 status = usb_add_function(c, &gser->port.func);
292 if (status)
293 kfree(gser);
294 return status;
295}