xref: /openbmc/linux/drivers/usb/usbip/vudc_sysfs.c (revision be709d48)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2015 Karol Kosik <karo9@interia.eu>
4  * Copyright (C) 2015-2016 Samsung Electronics
5  *               Igor Kotrasinski <i.kotrasinsk@samsung.com>
6  *               Krzysztof Opasiak <k.opasiak@samsung.com>
7  */
8 
9 #include <linux/device.h>
10 #include <linux/list.h>
11 #include <linux/usb/gadget.h>
12 #include <linux/usb/ch9.h>
13 #include <linux/sysfs.h>
14 #include <linux/kthread.h>
15 #include <linux/byteorder/generic.h>
16 
17 #include "usbip_common.h"
18 #include "vudc.h"
19 
20 #include <net/sock.h>
21 
22 /* called with udc->lock held */
23 int get_gadget_descs(struct vudc *udc)
24 {
25 	struct vrequest *usb_req;
26 	struct vep *ep0 = to_vep(udc->gadget.ep0);
27 	struct usb_device_descriptor *ddesc = &udc->dev_desc;
28 	struct usb_ctrlrequest req;
29 	int ret;
30 
31 	if (!udc->driver || !udc->pullup)
32 		return -EINVAL;
33 
34 	req.bRequestType = USB_DIR_IN | USB_TYPE_STANDARD | USB_RECIP_DEVICE;
35 	req.bRequest = USB_REQ_GET_DESCRIPTOR;
36 	req.wValue = cpu_to_le16(USB_DT_DEVICE << 8);
37 	req.wIndex = cpu_to_le16(0);
38 	req.wLength = cpu_to_le16(sizeof(*ddesc));
39 
40 	spin_unlock(&udc->lock);
41 	ret = udc->driver->setup(&(udc->gadget), &req);
42 	spin_lock(&udc->lock);
43 	if (ret < 0)
44 		goto out;
45 
46 	/* assuming request queue is empty; request is now on top */
47 	usb_req = list_last_entry(&ep0->req_queue, struct vrequest, req_entry);
48 	list_del(&usb_req->req_entry);
49 
50 	if (usb_req->req.length > sizeof(*ddesc)) {
51 		ret = -EOVERFLOW;
52 		goto giveback_req;
53 	}
54 
55 	memcpy(ddesc, usb_req->req.buf, sizeof(*ddesc));
56 	udc->desc_cached = 1;
57 	ret = 0;
58 giveback_req:
59 	usb_req->req.status = 0;
60 	usb_req->req.actual = usb_req->req.length;
61 	usb_gadget_giveback_request(&(ep0->ep), &(usb_req->req));
62 out:
63 	return ret;
64 }
65 
66 /*
67  * Exposes device descriptor from the gadget driver.
68  */
69 static ssize_t dev_desc_read(struct file *file, struct kobject *kobj,
70 			     struct bin_attribute *attr, char *out,
71 			     loff_t off, size_t count)
72 {
73 	struct device *dev = kobj_to_dev(kobj);
74 	struct vudc *udc = (struct vudc *)dev_get_drvdata(dev);
75 	char *desc_ptr = (char *) &udc->dev_desc;
76 	unsigned long flags;
77 	int ret;
78 
79 	spin_lock_irqsave(&udc->lock, flags);
80 	if (!udc->desc_cached) {
81 		ret = -ENODEV;
82 		goto unlock;
83 	}
84 
85 	memcpy(out, desc_ptr + off, count);
86 	ret = count;
87 unlock:
88 	spin_unlock_irqrestore(&udc->lock, flags);
89 	return ret;
90 }
91 static BIN_ATTR_RO(dev_desc, sizeof(struct usb_device_descriptor));
92 
93 static ssize_t usbip_sockfd_store(struct device *dev, struct device_attribute *attr,
94 		     const char *in, size_t count)
95 {
96 	struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
97 	int rv;
98 	int sockfd = 0;
99 	int err;
100 	struct socket *socket;
101 	unsigned long flags;
102 	int ret;
103 
104 	rv = kstrtoint(in, 0, &sockfd);
105 	if (rv != 0)
106 		return -EINVAL;
107 
108 	if (!udc) {
109 		dev_err(dev, "no device");
110 		return -ENODEV;
111 	}
112 	spin_lock_irqsave(&udc->lock, flags);
113 	/* Don't export what we don't have */
114 	if (!udc->driver || !udc->pullup) {
115 		dev_err(dev, "gadget not bound");
116 		ret = -ENODEV;
117 		goto unlock;
118 	}
119 
120 	if (sockfd != -1) {
121 		if (udc->connected) {
122 			dev_err(dev, "Device already connected");
123 			ret = -EBUSY;
124 			goto unlock;
125 		}
126 
127 		spin_lock_irq(&udc->ud.lock);
128 
129 		if (udc->ud.status != SDEV_ST_AVAILABLE) {
130 			ret = -EINVAL;
131 			goto unlock_ud;
132 		}
133 
134 		socket = sockfd_lookup(sockfd, &err);
135 		if (!socket) {
136 			dev_err(dev, "failed to lookup sock");
137 			ret = -EINVAL;
138 			goto unlock_ud;
139 		}
140 
141 		udc->ud.tcp_socket = socket;
142 
143 		spin_unlock_irq(&udc->ud.lock);
144 		spin_unlock_irqrestore(&udc->lock, flags);
145 
146 		udc->ud.tcp_rx = kthread_get_run(&v_rx_loop,
147 						    &udc->ud, "vudc_rx");
148 		udc->ud.tcp_tx = kthread_get_run(&v_tx_loop,
149 						    &udc->ud, "vudc_tx");
150 
151 		spin_lock_irqsave(&udc->lock, flags);
152 		spin_lock_irq(&udc->ud.lock);
153 		udc->ud.status = SDEV_ST_USED;
154 		spin_unlock_irq(&udc->ud.lock);
155 
156 		ktime_get_ts64(&udc->start_time);
157 		v_start_timer(udc);
158 		udc->connected = 1;
159 	} else {
160 		if (!udc->connected) {
161 			dev_err(dev, "Device not connected");
162 			ret = -EINVAL;
163 			goto unlock;
164 		}
165 
166 		spin_lock_irq(&udc->ud.lock);
167 		if (udc->ud.status != SDEV_ST_USED) {
168 			ret = -EINVAL;
169 			goto unlock_ud;
170 		}
171 		spin_unlock_irq(&udc->ud.lock);
172 
173 		usbip_event_add(&udc->ud, VUDC_EVENT_DOWN);
174 	}
175 
176 	spin_unlock_irqrestore(&udc->lock, flags);
177 
178 	return count;
179 
180 unlock_ud:
181 	spin_unlock_irq(&udc->ud.lock);
182 unlock:
183 	spin_unlock_irqrestore(&udc->lock, flags);
184 
185 	return ret;
186 }
187 static DEVICE_ATTR_WO(usbip_sockfd);
188 
189 static ssize_t usbip_status_show(struct device *dev,
190 			       struct device_attribute *attr, char *out)
191 {
192 	struct vudc *udc = (struct vudc *) dev_get_drvdata(dev);
193 	int status;
194 
195 	if (!udc) {
196 		dev_err(dev, "no device");
197 		return -ENODEV;
198 	}
199 	spin_lock_irq(&udc->ud.lock);
200 	status = udc->ud.status;
201 	spin_unlock_irq(&udc->ud.lock);
202 
203 	return snprintf(out, PAGE_SIZE, "%d\n", status);
204 }
205 static DEVICE_ATTR_RO(usbip_status);
206 
207 static struct attribute *dev_attrs[] = {
208 	&dev_attr_usbip_sockfd.attr,
209 	&dev_attr_usbip_status.attr,
210 	NULL,
211 };
212 
213 static struct bin_attribute *dev_bin_attrs[] = {
214 	&bin_attr_dev_desc,
215 	NULL,
216 };
217 
218 const struct attribute_group vudc_attr_group = {
219 	.attrs = dev_attrs,
220 	.bin_attrs = dev_bin_attrs,
221 };
222