1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * hid.c -- HID Composite driver
4 *
5 * Based on multi.c
6 *
7 * Copyright (C) 2010 Fabien Chouteau <fabien.chouteau@barco.com>
8 */
9
10
11 #include <linux/kernel.h>
12 #include <linux/platform_device.h>
13 #include <linux/list.h>
14 #include <linux/module.h>
15 #include <linux/usb/composite.h>
16 #include <linux/usb/g_hid.h>
17
18 #define DRIVER_DESC "HID Gadget"
19 #define DRIVER_VERSION "2010/03/16"
20
21 #include "u_hid.h"
22
23 /*-------------------------------------------------------------------------*/
24
25 #define HIDG_VENDOR_NUM 0x0525 /* XXX NetChip */
26 #define HIDG_PRODUCT_NUM 0xa4ac /* Linux-USB HID gadget */
27
28 /*-------------------------------------------------------------------------*/
29
30 struct hidg_func_node {
31 struct usb_function_instance *fi;
32 struct usb_function *f;
33 struct list_head node;
34 struct hidg_func_descriptor *func;
35 };
36
37 static LIST_HEAD(hidg_func_list);
38
39 /*-------------------------------------------------------------------------*/
40 USB_GADGET_COMPOSITE_OPTIONS();
41
42 static struct usb_device_descriptor device_desc = {
43 .bLength = sizeof device_desc,
44 .bDescriptorType = USB_DT_DEVICE,
45
46 /* .bcdUSB = DYNAMIC */
47
48 /* .bDeviceClass = USB_CLASS_COMM, */
49 /* .bDeviceSubClass = 0, */
50 /* .bDeviceProtocol = 0, */
51 .bDeviceClass = USB_CLASS_PER_INTERFACE,
52 .bDeviceSubClass = 0,
53 .bDeviceProtocol = 0,
54 /* .bMaxPacketSize0 = f(hardware) */
55
56 /* Vendor and product id can be overridden by module parameters. */
57 .idVendor = cpu_to_le16(HIDG_VENDOR_NUM),
58 .idProduct = cpu_to_le16(HIDG_PRODUCT_NUM),
59 /* .bcdDevice = f(hardware) */
60 /* .iManufacturer = DYNAMIC */
61 /* .iProduct = DYNAMIC */
62 /* NO SERIAL NUMBER */
63 .bNumConfigurations = 1,
64 };
65
66 static const struct usb_descriptor_header *otg_desc[2];
67
68 /* string IDs are assigned dynamically */
69 static struct usb_string strings_dev[] = {
70 [USB_GADGET_MANUFACTURER_IDX].s = "",
71 [USB_GADGET_PRODUCT_IDX].s = DRIVER_DESC,
72 [USB_GADGET_SERIAL_IDX].s = "",
73 { } /* end of list */
74 };
75
76 static struct usb_gadget_strings stringtab_dev = {
77 .language = 0x0409, /* en-us */
78 .strings = strings_dev,
79 };
80
81 static struct usb_gadget_strings *dev_strings[] = {
82 &stringtab_dev,
83 NULL,
84 };
85
86
87
88 /****************************** Configurations ******************************/
89
do_config(struct usb_configuration * c)90 static int do_config(struct usb_configuration *c)
91 {
92 struct hidg_func_node *e, *n;
93 int status = 0;
94
95 if (gadget_is_otg(c->cdev->gadget)) {
96 c->descriptors = otg_desc;
97 c->bmAttributes |= USB_CONFIG_ATT_WAKEUP;
98 }
99
100 list_for_each_entry(e, &hidg_func_list, node) {
101 e->f = usb_get_function(e->fi);
102 if (IS_ERR(e->f)) {
103 status = PTR_ERR(e->f);
104 goto put;
105 }
106 status = usb_add_function(c, e->f);
107 if (status < 0) {
108 usb_put_function(e->f);
109 goto put;
110 }
111 }
112
113 return 0;
114 put:
115 list_for_each_entry(n, &hidg_func_list, node) {
116 if (n == e)
117 break;
118 usb_remove_function(c, n->f);
119 usb_put_function(n->f);
120 }
121 return status;
122 }
123
124 static struct usb_configuration config_driver = {
125 .label = "HID Gadget",
126 .bConfigurationValue = 1,
127 /* .iConfiguration = DYNAMIC */
128 .bmAttributes = USB_CONFIG_ATT_SELFPOWER,
129 };
130
131 /****************************** Gadget Bind ******************************/
132
hid_bind(struct usb_composite_dev * cdev)133 static int hid_bind(struct usb_composite_dev *cdev)
134 {
135 struct usb_gadget *gadget = cdev->gadget;
136 struct list_head *tmp;
137 struct hidg_func_node *n = NULL, *m, *iter_n;
138 struct f_hid_opts *hid_opts;
139 int status, funcs = 0;
140
141 list_for_each(tmp, &hidg_func_list)
142 funcs++;
143
144 if (!funcs)
145 return -ENODEV;
146
147 list_for_each_entry(iter_n, &hidg_func_list, node) {
148 iter_n->fi = usb_get_function_instance("hid");
149 if (IS_ERR(iter_n->fi)) {
150 status = PTR_ERR(iter_n->fi);
151 n = iter_n;
152 goto put;
153 }
154 hid_opts = container_of(iter_n->fi, struct f_hid_opts, func_inst);
155 hid_opts->subclass = iter_n->func->subclass;
156 hid_opts->protocol = iter_n->func->protocol;
157 hid_opts->report_length = iter_n->func->report_length;
158 hid_opts->report_desc_length = iter_n->func->report_desc_length;
159 hid_opts->report_desc = iter_n->func->report_desc;
160 }
161
162
163 /* Allocate string descriptor numbers ... note that string
164 * contents can be overridden by the composite_dev glue.
165 */
166
167 status = usb_string_ids_tab(cdev, strings_dev);
168 if (status < 0)
169 goto put;
170 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
171 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
172
173 if (gadget_is_otg(gadget) && !otg_desc[0]) {
174 struct usb_descriptor_header *usb_desc;
175
176 usb_desc = usb_otg_descriptor_alloc(gadget);
177 if (!usb_desc) {
178 status = -ENOMEM;
179 goto put;
180 }
181 usb_otg_descriptor_init(gadget, usb_desc);
182 otg_desc[0] = usb_desc;
183 otg_desc[1] = NULL;
184 }
185
186 /* register our configuration */
187 status = usb_add_config(cdev, &config_driver, do_config);
188 if (status < 0)
189 goto free_otg_desc;
190
191 usb_composite_overwrite_options(cdev, &coverwrite);
192 dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
193
194 return 0;
195
196 free_otg_desc:
197 kfree(otg_desc[0]);
198 otg_desc[0] = NULL;
199 put:
200 list_for_each_entry(m, &hidg_func_list, node) {
201 if (m == n)
202 break;
203 usb_put_function_instance(m->fi);
204 }
205 return status;
206 }
207
hid_unbind(struct usb_composite_dev * cdev)208 static int hid_unbind(struct usb_composite_dev *cdev)
209 {
210 struct hidg_func_node *n;
211
212 list_for_each_entry(n, &hidg_func_list, node) {
213 usb_put_function(n->f);
214 usb_put_function_instance(n->fi);
215 }
216
217 kfree(otg_desc[0]);
218 otg_desc[0] = NULL;
219
220 return 0;
221 }
222
hidg_plat_driver_probe(struct platform_device * pdev)223 static int hidg_plat_driver_probe(struct platform_device *pdev)
224 {
225 struct hidg_func_descriptor *func = dev_get_platdata(&pdev->dev);
226 struct hidg_func_node *entry;
227
228 if (!func) {
229 dev_err(&pdev->dev, "Platform data missing\n");
230 return -ENODEV;
231 }
232
233 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
234 if (!entry)
235 return -ENOMEM;
236
237 entry->func = func;
238 list_add_tail(&entry->node, &hidg_func_list);
239
240 return 0;
241 }
242
hidg_plat_driver_remove(struct platform_device * pdev)243 static int hidg_plat_driver_remove(struct platform_device *pdev)
244 {
245 struct hidg_func_node *e, *n;
246
247 list_for_each_entry_safe(e, n, &hidg_func_list, node) {
248 list_del(&e->node);
249 kfree(e);
250 }
251
252 return 0;
253 }
254
255
256 /****************************** Some noise ******************************/
257
258
259 static struct usb_composite_driver hidg_driver = {
260 .name = "g_hid",
261 .dev = &device_desc,
262 .strings = dev_strings,
263 .max_speed = USB_SPEED_HIGH,
264 .bind = hid_bind,
265 .unbind = hid_unbind,
266 };
267
268 static struct platform_driver hidg_plat_driver = {
269 .remove = hidg_plat_driver_remove,
270 .driver = {
271 .name = "hidg",
272 },
273 };
274
275
276 MODULE_DESCRIPTION(DRIVER_DESC);
277 MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard");
278 MODULE_LICENSE("GPL");
279
hidg_init(void)280 static int __init hidg_init(void)
281 {
282 int status;
283
284 status = platform_driver_probe(&hidg_plat_driver,
285 hidg_plat_driver_probe);
286 if (status < 0)
287 return status;
288
289 status = usb_composite_probe(&hidg_driver);
290 if (status < 0)
291 platform_driver_unregister(&hidg_plat_driver);
292
293 return status;
294 }
295 module_init(hidg_init);
296
hidg_cleanup(void)297 static void __exit hidg_cleanup(void)
298 {
299 usb_composite_unregister(&hidg_driver);
300 platform_driver_unregister(&hidg_plat_driver);
301 }
302 module_exit(hidg_cleanup);
303