xref: /openbmc/linux/drivers/usb/core/endpoint.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/usb/core/endpoint.c
4  *
5  * (C) Copyright 2002,2004,2006 Greg Kroah-Hartman
6  * (C) Copyright 2002,2004 IBM Corp.
7  * (C) Copyright 2006 Novell Inc.
8  *
9  * Released under the GPLv2 only.
10  *
11  * Endpoint sysfs stuff
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/spinlock.h>
16 #include <linux/slab.h>
17 #include <linux/usb.h>
18 #include "usb.h"
19 
20 struct ep_device {
21 	struct usb_endpoint_descriptor *desc;
22 	struct usb_device *udev;
23 	struct device dev;
24 };
25 #define to_ep_device(_dev) \
26 	container_of(_dev, struct ep_device, dev)
27 
28 struct ep_attribute {
29 	struct attribute attr;
30 	ssize_t (*show)(struct usb_device *,
31 			struct usb_endpoint_descriptor *, char *);
32 };
33 #define to_ep_attribute(_attr) \
34 	container_of(_attr, struct ep_attribute, attr)
35 
36 #define usb_ep_attr(field, format_string)			\
37 static ssize_t field##_show(struct device *dev,			\
38 			       struct device_attribute *attr,	\
39 			       char *buf)			\
40 {								\
41 	struct ep_device *ep = to_ep_device(dev);		\
42 	return sprintf(buf, format_string, ep->desc->field);	\
43 }								\
44 static DEVICE_ATTR_RO(field)
45 
46 usb_ep_attr(bLength, "%02x\n");
47 usb_ep_attr(bEndpointAddress, "%02x\n");
48 usb_ep_attr(bmAttributes, "%02x\n");
49 usb_ep_attr(bInterval, "%02x\n");
50 
51 static ssize_t wMaxPacketSize_show(struct device *dev,
52 				   struct device_attribute *attr, char *buf)
53 {
54 	struct ep_device *ep = to_ep_device(dev);
55 	return sprintf(buf, "%04x\n", usb_endpoint_maxp(ep->desc));
56 }
57 static DEVICE_ATTR_RO(wMaxPacketSize);
58 
59 static ssize_t type_show(struct device *dev, struct device_attribute *attr,
60 			 char *buf)
61 {
62 	struct ep_device *ep = to_ep_device(dev);
63 	char *type = "unknown";
64 
65 	switch (usb_endpoint_type(ep->desc)) {
66 	case USB_ENDPOINT_XFER_CONTROL:
67 		type = "Control";
68 		break;
69 	case USB_ENDPOINT_XFER_ISOC:
70 		type = "Isoc";
71 		break;
72 	case USB_ENDPOINT_XFER_BULK:
73 		type = "Bulk";
74 		break;
75 	case USB_ENDPOINT_XFER_INT:
76 		type = "Interrupt";
77 		break;
78 	}
79 	return sprintf(buf, "%s\n", type);
80 }
81 static DEVICE_ATTR_RO(type);
82 
83 static ssize_t interval_show(struct device *dev, struct device_attribute *attr,
84 			     char *buf)
85 {
86 	struct ep_device *ep = to_ep_device(dev);
87 	char unit;
88 	unsigned interval = 0;
89 	unsigned in;
90 
91 	in = (ep->desc->bEndpointAddress & USB_DIR_IN);
92 
93 	switch (usb_endpoint_type(ep->desc)) {
94 	case USB_ENDPOINT_XFER_CONTROL:
95 		if (ep->udev->speed == USB_SPEED_HIGH)
96 			/* uframes per NAK */
97 			interval = ep->desc->bInterval;
98 		break;
99 
100 	case USB_ENDPOINT_XFER_ISOC:
101 		interval = 1 << (ep->desc->bInterval - 1);
102 		break;
103 
104 	case USB_ENDPOINT_XFER_BULK:
105 		if (ep->udev->speed == USB_SPEED_HIGH && !in)
106 			/* uframes per NAK */
107 			interval = ep->desc->bInterval;
108 		break;
109 
110 	case USB_ENDPOINT_XFER_INT:
111 		if (ep->udev->speed == USB_SPEED_HIGH)
112 			interval = 1 << (ep->desc->bInterval - 1);
113 		else
114 			interval = ep->desc->bInterval;
115 		break;
116 	}
117 	interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
118 	if (interval % 1000)
119 		unit = 'u';
120 	else {
121 		unit = 'm';
122 		interval /= 1000;
123 	}
124 
125 	return sprintf(buf, "%d%cs\n", interval, unit);
126 }
127 static DEVICE_ATTR_RO(interval);
128 
129 static ssize_t direction_show(struct device *dev, struct device_attribute *attr,
130 			      char *buf)
131 {
132 	struct ep_device *ep = to_ep_device(dev);
133 	char *direction;
134 
135 	if (usb_endpoint_xfer_control(ep->desc))
136 		direction = "both";
137 	else if (usb_endpoint_dir_in(ep->desc))
138 		direction = "in";
139 	else
140 		direction = "out";
141 	return sprintf(buf, "%s\n", direction);
142 }
143 static DEVICE_ATTR_RO(direction);
144 
145 static struct attribute *ep_dev_attrs[] = {
146 	&dev_attr_bLength.attr,
147 	&dev_attr_bEndpointAddress.attr,
148 	&dev_attr_bmAttributes.attr,
149 	&dev_attr_bInterval.attr,
150 	&dev_attr_wMaxPacketSize.attr,
151 	&dev_attr_interval.attr,
152 	&dev_attr_type.attr,
153 	&dev_attr_direction.attr,
154 	NULL,
155 };
156 static const struct attribute_group ep_dev_attr_grp = {
157 	.attrs = ep_dev_attrs,
158 };
159 static const struct attribute_group *ep_dev_groups[] = {
160 	&ep_dev_attr_grp,
161 	NULL
162 };
163 
164 static void ep_device_release(struct device *dev)
165 {
166 	struct ep_device *ep_dev = to_ep_device(dev);
167 
168 	kfree(ep_dev);
169 }
170 
171 struct device_type usb_ep_device_type = {
172 	.name =		"usb_endpoint",
173 	.release = ep_device_release,
174 };
175 
176 int usb_create_ep_devs(struct device *parent,
177 			struct usb_host_endpoint *endpoint,
178 			struct usb_device *udev)
179 {
180 	struct ep_device *ep_dev;
181 	int retval;
182 
183 	ep_dev = kzalloc(sizeof(*ep_dev), GFP_KERNEL);
184 	if (!ep_dev) {
185 		retval = -ENOMEM;
186 		goto exit;
187 	}
188 
189 	ep_dev->desc = &endpoint->desc;
190 	ep_dev->udev = udev;
191 	ep_dev->dev.groups = ep_dev_groups;
192 	ep_dev->dev.type = &usb_ep_device_type;
193 	ep_dev->dev.parent = parent;
194 	dev_set_name(&ep_dev->dev, "ep_%02x", endpoint->desc.bEndpointAddress);
195 
196 	retval = device_register(&ep_dev->dev);
197 	if (retval)
198 		goto error_register;
199 
200 	device_enable_async_suspend(&ep_dev->dev);
201 	endpoint->ep_dev = ep_dev;
202 	return retval;
203 
204 error_register:
205 	put_device(&ep_dev->dev);
206 exit:
207 	return retval;
208 }
209 
210 void usb_remove_ep_devs(struct usb_host_endpoint *endpoint)
211 {
212 	struct ep_device *ep_dev = endpoint->ep_dev;
213 
214 	if (ep_dev) {
215 		device_unregister(&ep_dev->dev);
216 		endpoint->ep_dev = NULL;
217 	}
218 }
219