1 | // SPDX-License-Identifier: GPL-2.0+ |
2 | /* |
3 | * serial.c -- USB gadget serial driver |
4 | * |
5 | * Copyright (C) 2003 Al Borchers (alborchers@steinerpoint.com) |
6 | * Copyright (C) 2008 by David Brownell |
7 | * Copyright (C) 2008 by Nokia Corporation |
8 | */ |
9 | |
10 | #include <linux/kernel.h> |
11 | #include <linux/device.h> |
12 | #include <linux/kstrtox.h> |
13 | #include <linux/module.h> |
14 | #include <linux/tty.h> |
15 | #include <linux/tty_flip.h> |
16 | |
17 | #include "u_serial.h" |
18 | |
19 | |
20 | /* Defines */ |
21 | |
22 | #define GS_VERSION_STR "v2.4" |
23 | #define GS_VERSION_NUM 0x2400 |
24 | |
25 | #define GS_LONG_NAME "Gadget Serial" |
26 | #define GS_VERSION_NAME GS_LONG_NAME " " GS_VERSION_STR |
27 | |
28 | /*-------------------------------------------------------------------------*/ |
29 | USB_GADGET_COMPOSITE_OPTIONS(); |
30 | |
31 | /* Thanks to NetChip Technologies for donating this product ID. |
32 | * |
33 | * DO NOT REUSE THESE IDs with a protocol-incompatible driver!! Ever!! |
34 | * Instead: allocate your own, using normal USB-IF procedures. |
35 | */ |
36 | #define GS_VENDOR_ID 0x0525 /* NetChip */ |
37 | #define GS_PRODUCT_ID 0xa4a6 /* Linux-USB Serial Gadget */ |
38 | #define GS_CDC_PRODUCT_ID 0xa4a7 /* ... as CDC-ACM */ |
39 | #define GS_CDC_OBEX_PRODUCT_ID 0xa4a9 /* ... as CDC-OBEX */ |
40 | |
41 | /* string IDs are assigned dynamically */ |
42 | |
43 | #define STRING_DESCRIPTION_IDX USB_GADGET_FIRST_AVAIL_IDX |
44 | |
45 | static struct usb_string strings_dev[] = { |
46 | [USB_GADGET_MANUFACTURER_IDX].s = "" , |
47 | [USB_GADGET_PRODUCT_IDX].s = GS_VERSION_NAME, |
48 | [USB_GADGET_SERIAL_IDX].s = "" , |
49 | [STRING_DESCRIPTION_IDX].s = NULL /* updated; f(use_acm) */, |
50 | { } /* end of list */ |
51 | }; |
52 | |
53 | static struct usb_gadget_strings stringtab_dev = { |
54 | .language = 0x0409, /* en-us */ |
55 | .strings = strings_dev, |
56 | }; |
57 | |
58 | static struct usb_gadget_strings *dev_strings[] = { |
59 | &stringtab_dev, |
60 | NULL, |
61 | }; |
62 | |
63 | static struct usb_device_descriptor device_desc = { |
64 | .bLength = USB_DT_DEVICE_SIZE, |
65 | .bDescriptorType = USB_DT_DEVICE, |
66 | /* .bcdUSB = DYNAMIC */ |
67 | /* .bDeviceClass = f(use_acm) */ |
68 | .bDeviceSubClass = 0, |
69 | .bDeviceProtocol = 0, |
70 | /* .bMaxPacketSize0 = f(hardware) */ |
71 | .idVendor = cpu_to_le16(GS_VENDOR_ID), |
72 | /* .idProduct = f(use_acm) */ |
73 | .bcdDevice = cpu_to_le16(GS_VERSION_NUM), |
74 | /* .iManufacturer = DYNAMIC */ |
75 | /* .iProduct = DYNAMIC */ |
76 | .bNumConfigurations = 1, |
77 | }; |
78 | |
79 | static const struct usb_descriptor_header *otg_desc[2]; |
80 | |
81 | /*-------------------------------------------------------------------------*/ |
82 | |
83 | /* Module */ |
84 | MODULE_DESCRIPTION(GS_VERSION_NAME); |
85 | MODULE_AUTHOR("Al Borchers" ); |
86 | MODULE_AUTHOR("David Brownell" ); |
87 | MODULE_LICENSE("GPL" ); |
88 | |
89 | static bool use_acm = true; |
90 | module_param(use_acm, bool, 0); |
91 | MODULE_PARM_DESC(use_acm, "Use CDC ACM, default=yes" ); |
92 | |
93 | static bool use_obex = false; |
94 | module_param(use_obex, bool, 0); |
95 | MODULE_PARM_DESC(use_obex, "Use CDC OBEX, default=no" ); |
96 | |
97 | static unsigned n_ports = 1; |
98 | module_param(n_ports, uint, 0); |
99 | MODULE_PARM_DESC(n_ports, "number of ports to create, default=1" ); |
100 | |
101 | static bool enable = true; |
102 | |
103 | static int switch_gserial_enable(bool do_enable); |
104 | |
105 | static int enable_set(const char *s, const struct kernel_param *kp) |
106 | { |
107 | bool do_enable; |
108 | int ret; |
109 | |
110 | if (!s) /* called for no-arg enable == default */ |
111 | return 0; |
112 | |
113 | ret = kstrtobool(s, res: &do_enable); |
114 | if (ret || enable == do_enable) |
115 | return ret; |
116 | |
117 | ret = switch_gserial_enable(do_enable); |
118 | if (!ret) |
119 | enable = do_enable; |
120 | |
121 | return ret; |
122 | } |
123 | |
124 | static const struct kernel_param_ops enable_ops = { |
125 | .set = enable_set, |
126 | .get = param_get_bool, |
127 | }; |
128 | |
129 | module_param_cb(enable, &enable_ops, &enable, 0644); |
130 | |
131 | /*-------------------------------------------------------------------------*/ |
132 | |
133 | static struct usb_configuration serial_config_driver = { |
134 | /* .label = f(use_acm) */ |
135 | /* .bConfigurationValue = f(use_acm) */ |
136 | /* .iConfiguration = DYNAMIC */ |
137 | .bmAttributes = USB_CONFIG_ATT_SELFPOWER, |
138 | }; |
139 | |
140 | static struct usb_function_instance *fi_serial[MAX_U_SERIAL_PORTS]; |
141 | static struct usb_function *f_serial[MAX_U_SERIAL_PORTS]; |
142 | |
143 | static int serial_register_ports(struct usb_composite_dev *cdev, |
144 | struct usb_configuration *c, const char *f_name) |
145 | { |
146 | int i; |
147 | int ret; |
148 | |
149 | ret = usb_add_config_only(cdev, config: c); |
150 | if (ret) |
151 | goto out; |
152 | |
153 | for (i = 0; i < n_ports; i++) { |
154 | |
155 | fi_serial[i] = usb_get_function_instance(name: f_name); |
156 | if (IS_ERR(ptr: fi_serial[i])) { |
157 | ret = PTR_ERR(ptr: fi_serial[i]); |
158 | goto fail; |
159 | } |
160 | |
161 | f_serial[i] = usb_get_function(fi: fi_serial[i]); |
162 | if (IS_ERR(ptr: f_serial[i])) { |
163 | ret = PTR_ERR(ptr: f_serial[i]); |
164 | goto err_get_func; |
165 | } |
166 | |
167 | ret = usb_add_function(c, f_serial[i]); |
168 | if (ret) |
169 | goto err_add_func; |
170 | } |
171 | |
172 | return 0; |
173 | |
174 | err_add_func: |
175 | usb_put_function(f: f_serial[i]); |
176 | err_get_func: |
177 | usb_put_function_instance(fi: fi_serial[i]); |
178 | |
179 | fail: |
180 | i--; |
181 | while (i >= 0) { |
182 | usb_remove_function(c, f: f_serial[i]); |
183 | usb_put_function(f: f_serial[i]); |
184 | usb_put_function_instance(fi: fi_serial[i]); |
185 | i--; |
186 | } |
187 | out: |
188 | return ret; |
189 | } |
190 | |
191 | static int gs_bind(struct usb_composite_dev *cdev) |
192 | { |
193 | int status; |
194 | |
195 | /* Allocate string descriptor numbers ... note that string |
196 | * contents can be overridden by the composite_dev glue. |
197 | */ |
198 | |
199 | status = usb_string_ids_tab(c: cdev, str: strings_dev); |
200 | if (status < 0) |
201 | goto fail; |
202 | device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id; |
203 | device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id; |
204 | status = strings_dev[STRING_DESCRIPTION_IDX].id; |
205 | serial_config_driver.iConfiguration = status; |
206 | |
207 | if (gadget_is_otg(g: cdev->gadget)) { |
208 | if (!otg_desc[0]) { |
209 | struct usb_descriptor_header *usb_desc; |
210 | |
211 | usb_desc = usb_otg_descriptor_alloc(gadget: cdev->gadget); |
212 | if (!usb_desc) { |
213 | status = -ENOMEM; |
214 | goto fail; |
215 | } |
216 | usb_otg_descriptor_init(gadget: cdev->gadget, otg_desc: usb_desc); |
217 | otg_desc[0] = usb_desc; |
218 | otg_desc[1] = NULL; |
219 | } |
220 | serial_config_driver.descriptors = otg_desc; |
221 | serial_config_driver.bmAttributes |= USB_CONFIG_ATT_WAKEUP; |
222 | } |
223 | |
224 | /* register our configuration */ |
225 | if (use_acm) { |
226 | status = serial_register_ports(cdev, c: &serial_config_driver, |
227 | f_name: "acm" ); |
228 | usb_ep_autoconfig_reset(cdev->gadget); |
229 | } else if (use_obex) |
230 | status = serial_register_ports(cdev, c: &serial_config_driver, |
231 | f_name: "obex" ); |
232 | else { |
233 | status = serial_register_ports(cdev, c: &serial_config_driver, |
234 | f_name: "gser" ); |
235 | } |
236 | if (status < 0) |
237 | goto fail1; |
238 | |
239 | usb_composite_overwrite_options(cdev, covr: &coverwrite); |
240 | INFO(cdev, "%s\n" , GS_VERSION_NAME); |
241 | |
242 | return 0; |
243 | fail1: |
244 | kfree(objp: otg_desc[0]); |
245 | otg_desc[0] = NULL; |
246 | fail: |
247 | return status; |
248 | } |
249 | |
250 | static int gs_unbind(struct usb_composite_dev *cdev) |
251 | { |
252 | int i; |
253 | |
254 | for (i = 0; i < n_ports; i++) { |
255 | usb_put_function(f: f_serial[i]); |
256 | usb_put_function_instance(fi: fi_serial[i]); |
257 | } |
258 | |
259 | kfree(objp: otg_desc[0]); |
260 | otg_desc[0] = NULL; |
261 | |
262 | return 0; |
263 | } |
264 | |
265 | static struct usb_composite_driver gserial_driver = { |
266 | .name = "g_serial" , |
267 | .dev = &device_desc, |
268 | .strings = dev_strings, |
269 | .max_speed = USB_SPEED_SUPER, |
270 | .bind = gs_bind, |
271 | .unbind = gs_unbind, |
272 | }; |
273 | |
274 | static int switch_gserial_enable(bool do_enable) |
275 | { |
276 | if (!serial_config_driver.label) |
277 | /* gserial_init() was not called, yet */ |
278 | return 0; |
279 | |
280 | if (do_enable) |
281 | return usb_composite_probe(driver: &gserial_driver); |
282 | |
283 | usb_composite_unregister(driver: &gserial_driver); |
284 | return 0; |
285 | } |
286 | |
287 | static int __init gserial_init(void) |
288 | { |
289 | /* We *could* export two configs; that'd be much cleaner... |
290 | * but neither of these product IDs was defined that way. |
291 | */ |
292 | if (use_acm) { |
293 | serial_config_driver.label = "CDC ACM config" ; |
294 | serial_config_driver.bConfigurationValue = 2; |
295 | device_desc.bDeviceClass = USB_CLASS_COMM; |
296 | device_desc.idProduct = |
297 | cpu_to_le16(GS_CDC_PRODUCT_ID); |
298 | } else if (use_obex) { |
299 | serial_config_driver.label = "CDC OBEX config" ; |
300 | serial_config_driver.bConfigurationValue = 3; |
301 | device_desc.bDeviceClass = USB_CLASS_COMM; |
302 | device_desc.idProduct = |
303 | cpu_to_le16(GS_CDC_OBEX_PRODUCT_ID); |
304 | } else { |
305 | serial_config_driver.label = "Generic Serial config" ; |
306 | serial_config_driver.bConfigurationValue = 1; |
307 | device_desc.bDeviceClass = USB_CLASS_VENDOR_SPEC; |
308 | device_desc.idProduct = |
309 | cpu_to_le16(GS_PRODUCT_ID); |
310 | } |
311 | strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label; |
312 | |
313 | if (!enable) |
314 | return 0; |
315 | |
316 | return usb_composite_probe(driver: &gserial_driver); |
317 | } |
318 | module_init(gserial_init); |
319 | |
320 | static void __exit gserial_cleanup(void) |
321 | { |
322 | if (enable) |
323 | usb_composite_unregister(driver: &gserial_driver); |
324 | } |
325 | module_exit(gserial_cleanup); |
326 | |