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
30struct 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
37static LIST_HEAD(hidg_func_list);
38
39/*-------------------------------------------------------------------------*/
40USB_GADGET_COMPOSITE_OPTIONS();
41
42static 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
66static const struct usb_descriptor_header *otg_desc[2];
67
68/* string IDs are assigned dynamically */
69static 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
76static struct usb_gadget_strings stringtab_dev = {
77 .language = 0x0409, /* en-us */
78 .strings = strings_dev,
79};
80
81static struct usb_gadget_strings *dev_strings[] = {
82 &stringtab_dev,
83 NULL,
84};
85
86
87
88/****************************** Configurations ******************************/
89
90static 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(g: 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(fi: e->fi);
102 if (IS_ERR(ptr: e->f)) {
103 status = PTR_ERR(ptr: e->f);
104 goto put;
105 }
106 status = usb_add_function(c, e->f);
107 if (status < 0) {
108 usb_put_function(f: e->f);
109 goto put;
110 }
111 }
112
113 return 0;
114put:
115 list_for_each_entry(n, &hidg_func_list, node) {
116 if (n == e)
117 break;
118 usb_remove_function(c, f: n->f);
119 usb_put_function(f: n->f);
120 }
121 return status;
122}
123
124static 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
133static int hid_bind(struct usb_composite_dev *cdev)
134{
135 struct usb_gadget *gadget = cdev->gadget;
136 struct hidg_func_node *n = NULL, *m, *iter_n;
137 struct f_hid_opts *hid_opts;
138 int status, funcs;
139
140 funcs = list_count_nodes(head: &hidg_func_list);
141 if (!funcs)
142 return -ENODEV;
143
144 list_for_each_entry(iter_n, &hidg_func_list, node) {
145 iter_n->fi = usb_get_function_instance(name: "hid");
146 if (IS_ERR(ptr: iter_n->fi)) {
147 status = PTR_ERR(ptr: iter_n->fi);
148 n = iter_n;
149 goto put;
150 }
151 hid_opts = container_of(iter_n->fi, struct f_hid_opts, func_inst);
152 hid_opts->subclass = iter_n->func->subclass;
153 hid_opts->protocol = iter_n->func->protocol;
154 hid_opts->report_length = iter_n->func->report_length;
155 hid_opts->report_desc_length = iter_n->func->report_desc_length;
156 hid_opts->report_desc = iter_n->func->report_desc;
157 }
158
159
160 /* Allocate string descriptor numbers ... note that string
161 * contents can be overridden by the composite_dev glue.
162 */
163
164 status = usb_string_ids_tab(c: cdev, str: strings_dev);
165 if (status < 0)
166 goto put;
167 device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
168 device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
169
170 if (gadget_is_otg(g: gadget) && !otg_desc[0]) {
171 struct usb_descriptor_header *usb_desc;
172
173 usb_desc = usb_otg_descriptor_alloc(gadget);
174 if (!usb_desc) {
175 status = -ENOMEM;
176 goto put;
177 }
178 usb_otg_descriptor_init(gadget, otg_desc: usb_desc);
179 otg_desc[0] = usb_desc;
180 otg_desc[1] = NULL;
181 }
182
183 /* register our configuration */
184 status = usb_add_config(cdev, &config_driver, do_config);
185 if (status < 0)
186 goto free_otg_desc;
187
188 usb_composite_overwrite_options(cdev, covr: &coverwrite);
189 dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
190
191 return 0;
192
193free_otg_desc:
194 kfree(objp: otg_desc[0]);
195 otg_desc[0] = NULL;
196put:
197 list_for_each_entry(m, &hidg_func_list, node) {
198 if (m == n)
199 break;
200 usb_put_function_instance(fi: m->fi);
201 }
202 return status;
203}
204
205static int hid_unbind(struct usb_composite_dev *cdev)
206{
207 struct hidg_func_node *n;
208
209 list_for_each_entry(n, &hidg_func_list, node) {
210 usb_put_function(f: n->f);
211 usb_put_function_instance(fi: n->fi);
212 }
213
214 kfree(objp: otg_desc[0]);
215 otg_desc[0] = NULL;
216
217 return 0;
218}
219
220static int hidg_plat_driver_probe(struct platform_device *pdev)
221{
222 struct hidg_func_descriptor *func = dev_get_platdata(dev: &pdev->dev);
223 struct hidg_func_node *entry;
224
225 if (!func) {
226 dev_err(&pdev->dev, "Platform data missing\n");
227 return -ENODEV;
228 }
229
230 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
231 if (!entry)
232 return -ENOMEM;
233
234 entry->func = func;
235 list_add_tail(new: &entry->node, head: &hidg_func_list);
236
237 return 0;
238}
239
240static void hidg_plat_driver_remove(struct platform_device *pdev)
241{
242 struct hidg_func_node *e, *n;
243
244 list_for_each_entry_safe(e, n, &hidg_func_list, node) {
245 list_del(entry: &e->node);
246 kfree(objp: e);
247 }
248}
249
250
251/****************************** Some noise ******************************/
252
253
254static struct usb_composite_driver hidg_driver = {
255 .name = "g_hid",
256 .dev = &device_desc,
257 .strings = dev_strings,
258 .max_speed = USB_SPEED_HIGH,
259 .bind = hid_bind,
260 .unbind = hid_unbind,
261};
262
263static struct platform_driver hidg_plat_driver = {
264 .remove = hidg_plat_driver_remove,
265 .driver = {
266 .name = "hidg",
267 },
268};
269
270
271MODULE_DESCRIPTION(DRIVER_DESC);
272MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard");
273MODULE_LICENSE("GPL");
274
275static int __init hidg_init(void)
276{
277 int status;
278
279 status = platform_driver_probe(&hidg_plat_driver,
280 hidg_plat_driver_probe);
281 if (status < 0)
282 return status;
283
284 status = usb_composite_probe(driver: &hidg_driver);
285 if (status < 0)
286 platform_driver_unregister(&hidg_plat_driver);
287
288 return status;
289}
290module_init(hidg_init);
291
292static void __exit hidg_cleanup(void)
293{
294 usb_composite_unregister(driver: &hidg_driver);
295 platform_driver_unregister(&hidg_plat_driver);
296}
297module_exit(hidg_cleanup);
298

source code of linux/drivers/usb/gadget/legacy/hid.c