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(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;
114put:
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
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 list_head *tmp;
137	struct hidg_func_node *n, *m;
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(n, &hidg_func_list, node) {
148		n->fi = usb_get_function_instance("hid");
149		if (IS_ERR(n->fi)) {
150			status = PTR_ERR(n->fi);
151			goto put;
152		}
153		hid_opts = container_of(n->fi, struct f_hid_opts, func_inst);
154		hid_opts->subclass = n->func->subclass;
155		hid_opts->protocol = n->func->protocol;
156		hid_opts->report_length = n->func->report_length;
157		hid_opts->report_desc_length = n->func->report_desc_length;
158		hid_opts->report_desc = n->func->report_desc;
159	}
160
161
162	/* Allocate string descriptor numbers ... note that string
163	 * contents can be overridden by the composite_dev glue.
164	 */
165
166	status = usb_string_ids_tab(cdev, strings_dev);
167	if (status < 0)
168		goto put;
169	device_desc.iManufacturer = strings_dev[USB_GADGET_MANUFACTURER_IDX].id;
170	device_desc.iProduct = strings_dev[USB_GADGET_PRODUCT_IDX].id;
171
172	if (gadget_is_otg(gadget) && !otg_desc[0]) {
173		struct usb_descriptor_header *usb_desc;
174
175		usb_desc = usb_otg_descriptor_alloc(gadget);
176		if (!usb_desc) {
177			status = -ENOMEM;
178			goto put;
179		}
180		usb_otg_descriptor_init(gadget, usb_desc);
181		otg_desc[0] = usb_desc;
182		otg_desc[1] = NULL;
183	}
184
185	/* register our configuration */
186	status = usb_add_config(cdev, &config_driver, do_config);
187	if (status < 0)
188		goto free_otg_desc;
189
190	usb_composite_overwrite_options(cdev, &coverwrite);
191	dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
192
193	return 0;
194
195free_otg_desc:
196	kfree(otg_desc[0]);
197	otg_desc[0] = NULL;
198put:
199	list_for_each_entry(m, &hidg_func_list, node) {
200		if (m == n)
201			break;
202		usb_put_function_instance(m->fi);
203	}
204	return status;
205}
206
207static int hid_unbind(struct usb_composite_dev *cdev)
208{
209	struct hidg_func_node *n;
210
211	list_for_each_entry(n, &hidg_func_list, node) {
212		usb_put_function(n->f);
213		usb_put_function_instance(n->fi);
214	}
215
216	kfree(otg_desc[0]);
217	otg_desc[0] = NULL;
218
219	return 0;
220}
221
222static int hidg_plat_driver_probe(struct platform_device *pdev)
223{
224	struct hidg_func_descriptor *func = dev_get_platdata(&pdev->dev);
225	struct hidg_func_node *entry;
226
227	if (!func) {
228		dev_err(&pdev->dev, "Platform data missing\n");
229		return -ENODEV;
230	}
231
232	entry = kzalloc(sizeof(*entry), GFP_KERNEL);
233	if (!entry)
234		return -ENOMEM;
235
236	entry->func = func;
237	list_add_tail(&entry->node, &hidg_func_list);
238
239	return 0;
240}
241
242static int hidg_plat_driver_remove(struct platform_device *pdev)
243{
244	struct hidg_func_node *e, *n;
245
246	list_for_each_entry_safe(e, n, &hidg_func_list, node) {
247		list_del(&e->node);
248		kfree(e);
249	}
250
251	return 0;
252}
253
254
255/****************************** Some noise ******************************/
256
257
258static struct usb_composite_driver hidg_driver = {
259	.name		= "g_hid",
260	.dev		= &device_desc,
261	.strings	= dev_strings,
262	.max_speed	= USB_SPEED_HIGH,
263	.bind		= hid_bind,
264	.unbind		= hid_unbind,
265};
266
267static struct platform_driver hidg_plat_driver = {
268	.remove		= hidg_plat_driver_remove,
269	.driver		= {
270		.name	= "hidg",
271	},
272};
273
274
275MODULE_DESCRIPTION(DRIVER_DESC);
276MODULE_AUTHOR("Fabien Chouteau, Peter Korsgaard");
277MODULE_LICENSE("GPL");
278
279static int __init hidg_init(void)
280{
281	int status;
282
283	status = platform_driver_probe(&hidg_plat_driver,
284				hidg_plat_driver_probe);
285	if (status < 0)
286		return status;
287
288	status = usb_composite_probe(&hidg_driver);
289	if (status < 0)
290		platform_driver_unregister(&hidg_plat_driver);
291
292	return status;
293}
294module_init(hidg_init);
295
296static void __exit hidg_cleanup(void)
297{
298	usb_composite_unregister(&hidg_driver);
299	platform_driver_unregister(&hidg_plat_driver);
300}
301module_exit(hidg_cleanup);
302