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1/*
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
13#include <linux/slab.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/device.h>
17
18#include "u_serial.h"
19#include "gadget_chips.h"
20
21
22/*
23 * This function packages a simple "generic serial" port with no real
24 * control mechanisms, just raw data transfer over two bulk endpoints.
25 *
26 * Because it's not standardized, this isn't as interoperable as the
27 * CDC ACM driver. However, for many purposes it's just as functional
28 * if you can arrange appropriate host side drivers.
29 */
30
31struct f_gser {
32 struct gserial port;
33 u8 data_id;
34 u8 port_num;
35};
36
37static inline struct f_gser *func_to_gser(struct usb_function *f)
38{
39 return container_of(f, struct f_gser, port.func);
40}
41
42/*-------------------------------------------------------------------------*/
43
44/* interface descriptor: */
45
46static struct usb_interface_descriptor gser_interface_desc = {
47 .bLength = USB_DT_INTERFACE_SIZE,
48 .bDescriptorType = USB_DT_INTERFACE,
49 /* .bInterfaceNumber = DYNAMIC */
50 .bNumEndpoints = 2,
51 .bInterfaceClass = USB_CLASS_VENDOR_SPEC,
52 .bInterfaceSubClass = 0,
53 .bInterfaceProtocol = 0,
54 /* .iInterface = DYNAMIC */
55};
56
57/* full speed support: */
58
59static struct usb_endpoint_descriptor gser_fs_in_desc = {
60 .bLength = USB_DT_ENDPOINT_SIZE,
61 .bDescriptorType = USB_DT_ENDPOINT,
62 .bEndpointAddress = USB_DIR_IN,
63 .bmAttributes = USB_ENDPOINT_XFER_BULK,
64};
65
66static struct usb_endpoint_descriptor gser_fs_out_desc = {
67 .bLength = USB_DT_ENDPOINT_SIZE,
68 .bDescriptorType = USB_DT_ENDPOINT,
69 .bEndpointAddress = USB_DIR_OUT,
70 .bmAttributes = USB_ENDPOINT_XFER_BULK,
71};
72
73static struct usb_descriptor_header *gser_fs_function[] = {
74 (struct usb_descriptor_header *) &gser_interface_desc,
75 (struct usb_descriptor_header *) &gser_fs_in_desc,
76 (struct usb_descriptor_header *) &gser_fs_out_desc,
77 NULL,
78};
79
80/* high speed support: */
81
82static struct usb_endpoint_descriptor gser_hs_in_desc = {
83 .bLength = USB_DT_ENDPOINT_SIZE,
84 .bDescriptorType = USB_DT_ENDPOINT,
85 .bmAttributes = USB_ENDPOINT_XFER_BULK,
86 .wMaxPacketSize = cpu_to_le16(512),
87};
88
89static struct usb_endpoint_descriptor gser_hs_out_desc = {
90 .bLength = USB_DT_ENDPOINT_SIZE,
91 .bDescriptorType = USB_DT_ENDPOINT,
92 .bmAttributes = USB_ENDPOINT_XFER_BULK,
93 .wMaxPacketSize = cpu_to_le16(512),
94};
95
96static struct usb_descriptor_header *gser_hs_function[] = {
97 (struct usb_descriptor_header *) &gser_interface_desc,
98 (struct usb_descriptor_header *) &gser_hs_in_desc,
99 (struct usb_descriptor_header *) &gser_hs_out_desc,
100 NULL,
101};
102
103static struct usb_endpoint_descriptor gser_ss_in_desc = {
104 .bLength = USB_DT_ENDPOINT_SIZE,
105 .bDescriptorType = USB_DT_ENDPOINT,
106 .bmAttributes = USB_ENDPOINT_XFER_BULK,
107 .wMaxPacketSize = cpu_to_le16(1024),
108};
109
110static struct usb_endpoint_descriptor gser_ss_out_desc = {
111 .bLength = USB_DT_ENDPOINT_SIZE,
112 .bDescriptorType = USB_DT_ENDPOINT,
113 .bmAttributes = USB_ENDPOINT_XFER_BULK,
114 .wMaxPacketSize = cpu_to_le16(1024),
115};
116
117static struct usb_ss_ep_comp_descriptor gser_ss_bulk_comp_desc = {
118 .bLength = sizeof gser_ss_bulk_comp_desc,
119 .bDescriptorType = USB_DT_SS_ENDPOINT_COMP,
120};
121
122static struct usb_descriptor_header *gser_ss_function[] = {
123 (struct usb_descriptor_header *) &gser_interface_desc,
124 (struct usb_descriptor_header *) &gser_ss_in_desc,
125 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
126 (struct usb_descriptor_header *) &gser_ss_out_desc,
127 (struct usb_descriptor_header *) &gser_ss_bulk_comp_desc,
128 NULL,
129};
130
131/* string descriptors: */
132
133static struct usb_string gser_string_defs[] = {
134 [0].s = "Generic Serial",
135 { } /* end of list */
136};
137
138static struct usb_gadget_strings gser_string_table = {
139 .language = 0x0409, /* en-us */
140 .strings = gser_string_defs,
141};
142
143static struct usb_gadget_strings *gser_strings[] = {
144 &gser_string_table,
145 NULL,
146};
147
148/*-------------------------------------------------------------------------*/
149
150static int gser_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
151{
152 struct f_gser *gser = func_to_gser(f);
153 struct usb_composite_dev *cdev = f->config->cdev;
154
155 /* we know alt == 0, so this is an activation or a reset */
156
157 if (gser->port.in->driver_data) {
158 DBG(cdev, "reset generic ttyGS%d\n", gser->port_num);
159 gserial_disconnect(&gser->port);
160 }
161 if (!gser->port.in->desc || !gser->port.out->desc) {
162 DBG(cdev, "activate generic ttyGS%d\n", gser->port_num);
163 if (config_ep_by_speed(cdev->gadget, f, gser->port.in) ||
164 config_ep_by_speed(cdev->gadget, f, gser->port.out)) {
165 gser->port.in->desc = NULL;
166 gser->port.out->desc = NULL;
167 return -EINVAL;
168 }
169 }
170 gserial_connect(&gser->port, gser->port_num);
171 return 0;
172}
173
174static void gser_disable(struct usb_function *f)
175{
176 struct f_gser *gser = func_to_gser(f);
177 struct usb_composite_dev *cdev = f->config->cdev;
178
179 DBG(cdev, "generic ttyGS%d deactivated\n", gser->port_num);
180 gserial_disconnect(&gser->port);
181}
182
183/*-------------------------------------------------------------------------*/
184
185/* serial function driver setup/binding */
186
187static int gser_bind(struct usb_configuration *c, struct usb_function *f)
188{
189 struct usb_composite_dev *cdev = c->cdev;
190 struct f_gser *gser = func_to_gser(f);
191 int status;
192 struct usb_ep *ep;
193
194 /* REVISIT might want instance-specific strings to help
195 * distinguish instances ...
196 */
197
198 /* maybe allocate device-global string ID */
199 if (gser_string_defs[0].id == 0) {
200 status = usb_string_id(c->cdev);
201 if (status < 0)
202 return status;
203 gser_string_defs[0].id = status;
204 }
205
206 /* allocate instance-specific interface IDs */
207 status = usb_interface_id(c, f);
208 if (status < 0)
209 goto fail;
210 gser->data_id = status;
211 gser_interface_desc.bInterfaceNumber = status;
212
213 status = -ENODEV;
214
215 /* allocate instance-specific endpoints */
216 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_in_desc);
217 if (!ep)
218 goto fail;
219 gser->port.in = ep;
220 ep->driver_data = cdev; /* claim */
221
222 ep = usb_ep_autoconfig(cdev->gadget, &gser_fs_out_desc);
223 if (!ep)
224 goto fail;
225 gser->port.out = ep;
226 ep->driver_data = cdev; /* claim */
227
228 /* support all relevant hardware speeds... we expect that when
229 * hardware is dual speed, all bulk-capable endpoints work at
230 * both speeds
231 */
232 gser_hs_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
233 gser_hs_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
234
235 gser_ss_in_desc.bEndpointAddress = gser_fs_in_desc.bEndpointAddress;
236 gser_ss_out_desc.bEndpointAddress = gser_fs_out_desc.bEndpointAddress;
237
238 status = usb_assign_descriptors(f, gser_fs_function, gser_hs_function,
239 gser_ss_function);
240 if (status)
241 goto fail;
242 DBG(cdev, "generic ttyGS%d: %s speed IN/%s OUT/%s\n",
243 gser->port_num,
244 gadget_is_superspeed(c->cdev->gadget) ? "super" :
245 gadget_is_dualspeed(c->cdev->gadget) ? "dual" : "full",
246 gser->port.in->name, gser->port.out->name);
247 return 0;
248
249fail:
250 /* we might as well release our claims on endpoints */
251 if (gser->port.out)
252 gser->port.out->driver_data = NULL;
253 if (gser->port.in)
254 gser->port.in->driver_data = NULL;
255
256 ERROR(cdev, "%s: can't bind, err %d\n", f->name, status);
257
258 return status;
259}
260
261static inline struct f_serial_opts *to_f_serial_opts(struct config_item *item)
262{
263 return container_of(to_config_group(item), struct f_serial_opts,
264 func_inst.group);
265}
266
267CONFIGFS_ATTR_STRUCT(f_serial_opts);
268static ssize_t f_serial_attr_show(struct config_item *item,
269 struct configfs_attribute *attr,
270 char *page)
271{
272 struct f_serial_opts *opts = to_f_serial_opts(item);
273 struct f_serial_opts_attribute *f_serial_opts_attr =
274 container_of(attr, struct f_serial_opts_attribute, attr);
275 ssize_t ret = 0;
276
277 if (f_serial_opts_attr->show)
278 ret = f_serial_opts_attr->show(opts, page);
279
280 return ret;
281}
282
283static void serial_attr_release(struct config_item *item)
284{
285 struct f_serial_opts *opts = to_f_serial_opts(item);
286
287 usb_put_function_instance(&opts->func_inst);
288}
289
290static struct configfs_item_operations serial_item_ops = {
291 .release = serial_attr_release,
292 .show_attribute = f_serial_attr_show,
293};
294
295static ssize_t f_serial_port_num_show(struct f_serial_opts *opts, char *page)
296{
297 return sprintf(page, "%u\n", opts->port_num);
298}
299
300static struct f_serial_opts_attribute f_serial_port_num =
301 __CONFIGFS_ATTR_RO(port_num, f_serial_port_num_show);
302
303static struct configfs_attribute *acm_attrs[] = {
304 &f_serial_port_num.attr,
305 NULL,
306};
307
308static struct config_item_type serial_func_type = {
309 .ct_item_ops = &serial_item_ops,
310 .ct_attrs = acm_attrs,
311 .ct_owner = THIS_MODULE,
312};
313
314static void gser_free_inst(struct usb_function_instance *f)
315{
316 struct f_serial_opts *opts;
317
318 opts = container_of(f, struct f_serial_opts, func_inst);
319 gserial_free_line(opts->port_num);
320 kfree(opts);
321}
322
323static struct usb_function_instance *gser_alloc_inst(void)
324{
325 struct f_serial_opts *opts;
326 int ret;
327
328 opts = kzalloc(sizeof(*opts), GFP_KERNEL);
329 if (!opts)
330 return ERR_PTR(-ENOMEM);
331
332 opts->func_inst.free_func_inst = gser_free_inst;
333 ret = gserial_alloc_line(&opts->port_num);
334 if (ret) {
335 kfree(opts);
336 return ERR_PTR(ret);
337 }
338 config_group_init_type_name(&opts->func_inst.group, "",
339 &serial_func_type);
340
341 return &opts->func_inst;
342}
343
344static void gser_free(struct usb_function *f)
345{
346 struct f_gser *serial;
347
348 serial = func_to_gser(f);
349 kfree(serial);
350}
351
352static void gser_unbind(struct usb_configuration *c, struct usb_function *f)
353{
354 usb_free_all_descriptors(f);
355}
356
357static struct usb_function *gser_alloc(struct usb_function_instance *fi)
358{
359 struct f_gser *gser;
360 struct f_serial_opts *opts;
361
362 /* allocate and initialize one new instance */
363 gser = kzalloc(sizeof(*gser), GFP_KERNEL);
364 if (!gser)
365 return ERR_PTR(-ENOMEM);
366
367 opts = container_of(fi, struct f_serial_opts, func_inst);
368
369 gser->port_num = opts->port_num;
370
371 gser->port.func.name = "gser";
372 gser->port.func.strings = gser_strings;
373 gser->port.func.bind = gser_bind;
374 gser->port.func.unbind = gser_unbind;
375 gser->port.func.set_alt = gser_set_alt;
376 gser->port.func.disable = gser_disable;
377 gser->port.func.free_func = gser_free;
378
379 return &gser->port.func;
380}
381
382DECLARE_USB_FUNCTION_INIT(gser, gser_alloc_inst, gser_alloc);
383MODULE_LICENSE("GPL");
384MODULE_AUTHOR("Al Borchers");
385MODULE_AUTHOR("David Brownell");