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 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(&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("hid");
146		if (IS_ERR(iter_n->fi)) {
147			status = PTR_ERR(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(cdev, 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(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, 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, &coverwrite);
189	dev_info(&gadget->dev, DRIVER_DESC ", version: " DRIVER_VERSION "\n");
190
191	return 0;
192
193free_otg_desc:
194	kfree(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(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(n->f);
211		usb_put_function_instance(n->fi);
212	}
213
214	kfree(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(&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(&entry->node, &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(&e->node);
246		kfree(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_new	= 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(&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(&hidg_driver);
295	platform_driver_unregister(&hidg_plat_driver);
296}
297module_exit(hidg_cleanup);
298