xref: /openbmc/linux/drivers/usb/core/endpoint.c (revision a1e58bbd)
1 /*
2  * drivers/usb/core/endpoint.c
3  *
4  * (C) Copyright 2002,2004,2006 Greg Kroah-Hartman
5  * (C) Copyright 2002,2004 IBM Corp.
6  * (C) Copyright 2006 Novell Inc.
7  *
8  * Endpoint sysfs stuff
9  *
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/spinlock.h>
14 #include <linux/idr.h>
15 #include <linux/usb.h>
16 #include "usb.h"
17 
18 #define MAX_ENDPOINT_MINORS (64*128*32)
19 static int usb_endpoint_major;
20 static DEFINE_IDR(endpoint_idr);
21 
22 struct ep_device {
23 	struct usb_endpoint_descriptor *desc;
24 	struct usb_device *udev;
25 	struct device dev;
26 	int minor;
27 };
28 #define to_ep_device(_dev) \
29 	container_of(_dev, struct ep_device, dev)
30 
31 struct ep_attribute {
32 	struct attribute attr;
33 	ssize_t (*show)(struct usb_device *,
34 			struct usb_endpoint_descriptor *, char *);
35 };
36 #define to_ep_attribute(_attr) \
37 	container_of(_attr, struct ep_attribute, attr)
38 
39 #define usb_ep_attr(field, format_string)			\
40 static ssize_t show_ep_##field(struct device *dev,		\
41 			       struct device_attribute *attr,	\
42 			       char *buf)			\
43 {								\
44 	struct ep_device *ep = to_ep_device(dev);		\
45 	return sprintf(buf, format_string, ep->desc->field);	\
46 }								\
47 static DEVICE_ATTR(field, S_IRUGO, show_ep_##field, NULL);
48 
49 usb_ep_attr(bLength, "%02x\n")
50 usb_ep_attr(bEndpointAddress, "%02x\n")
51 usb_ep_attr(bmAttributes, "%02x\n")
52 usb_ep_attr(bInterval, "%02x\n")
53 
54 static ssize_t show_ep_wMaxPacketSize(struct device *dev,
55 				      struct device_attribute *attr, char *buf)
56 {
57 	struct ep_device *ep = to_ep_device(dev);
58 	return sprintf(buf, "%04x\n",
59 			le16_to_cpu(ep->desc->wMaxPacketSize) & 0x07ff);
60 }
61 static DEVICE_ATTR(wMaxPacketSize, S_IRUGO, show_ep_wMaxPacketSize, NULL);
62 
63 static ssize_t show_ep_type(struct device *dev, struct device_attribute *attr,
64 			    char *buf)
65 {
66 	struct ep_device *ep = to_ep_device(dev);
67 	char *type = "unknown";
68 
69 	switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
70 	case USB_ENDPOINT_XFER_CONTROL:
71 		type = "Control";
72 		break;
73 	case USB_ENDPOINT_XFER_ISOC:
74 		type = "Isoc";
75 		break;
76 	case USB_ENDPOINT_XFER_BULK:
77 		type = "Bulk";
78 		break;
79 	case USB_ENDPOINT_XFER_INT:
80 		type = "Interrupt";
81 		break;
82 	}
83 	return sprintf(buf, "%s\n", type);
84 }
85 static DEVICE_ATTR(type, S_IRUGO, show_ep_type, NULL);
86 
87 static ssize_t show_ep_interval(struct device *dev,
88 				struct device_attribute *attr, char *buf)
89 {
90 	struct ep_device *ep = to_ep_device(dev);
91 	char unit;
92 	unsigned interval = 0;
93 	unsigned in;
94 
95 	in = (ep->desc->bEndpointAddress & USB_DIR_IN);
96 
97 	switch (ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) {
98 	case USB_ENDPOINT_XFER_CONTROL:
99 		if (ep->udev->speed == USB_SPEED_HIGH) 	/* uframes per NAK */
100 			interval = ep->desc->bInterval;
101 		break;
102 	case USB_ENDPOINT_XFER_ISOC:
103 		interval = 1 << (ep->desc->bInterval - 1);
104 		break;
105 	case USB_ENDPOINT_XFER_BULK:
106 		if (ep->udev->speed == USB_SPEED_HIGH && !in) /* uframes per NAK */
107 			interval = ep->desc->bInterval;
108 		break;
109 	case USB_ENDPOINT_XFER_INT:
110 		if (ep->udev->speed == USB_SPEED_HIGH)
111 			interval = 1 << (ep->desc->bInterval - 1);
112 		else
113 			interval = ep->desc->bInterval;
114 		break;
115 	}
116 	interval *= (ep->udev->speed == USB_SPEED_HIGH) ? 125 : 1000;
117 	if (interval % 1000)
118 		unit = 'u';
119 	else {
120 		unit = 'm';
121 		interval /= 1000;
122 	}
123 
124 	return sprintf(buf, "%d%cs\n", interval, unit);
125 }
126 static DEVICE_ATTR(interval, S_IRUGO, show_ep_interval, NULL);
127 
128 static ssize_t show_ep_direction(struct device *dev,
129 				 struct device_attribute *attr, char *buf)
130 {
131 	struct ep_device *ep = to_ep_device(dev);
132 	char *direction;
133 
134 	if ((ep->desc->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
135 			USB_ENDPOINT_XFER_CONTROL)
136 		direction = "both";
137 	else if (ep->desc->bEndpointAddress & USB_DIR_IN)
138 		direction = "in";
139 	else
140 		direction = "out";
141 	return sprintf(buf, "%s\n", direction);
142 }
143 static DEVICE_ATTR(direction, S_IRUGO, show_ep_direction, NULL);
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 struct attribute_group ep_dev_attr_grp = {
157 	.attrs = ep_dev_attrs,
158 };
159 
160 static int usb_endpoint_major_init(void)
161 {
162 	dev_t dev;
163 	int error;
164 
165 	error = alloc_chrdev_region(&dev, 0, MAX_ENDPOINT_MINORS,
166 				    "usb_endpoint");
167 	if (error) {
168 		err("unable to get a dynamic major for usb endpoints");
169 		return error;
170 	}
171 	usb_endpoint_major = MAJOR(dev);
172 
173 	return error;
174 }
175 
176 static void usb_endpoint_major_cleanup(void)
177 {
178 	unregister_chrdev_region(MKDEV(usb_endpoint_major, 0),
179 				 MAX_ENDPOINT_MINORS);
180 }
181 
182 static int endpoint_get_minor(struct ep_device *ep_dev)
183 {
184 	static DEFINE_MUTEX(minor_lock);
185 	int retval = -ENOMEM;
186 	int id;
187 
188 	mutex_lock(&minor_lock);
189 	if (idr_pre_get(&endpoint_idr, GFP_KERNEL) == 0)
190 		goto exit;
191 
192 	retval = idr_get_new(&endpoint_idr, ep_dev, &id);
193 	if (retval < 0) {
194 		if (retval == -EAGAIN)
195 			retval = -ENOMEM;
196 		goto exit;
197 	}
198 	ep_dev->minor = id & MAX_ID_MASK;
199 exit:
200 	mutex_unlock(&minor_lock);
201 	return retval;
202 }
203 
204 static void endpoint_free_minor(struct ep_device *ep_dev)
205 {
206 	idr_remove(&endpoint_idr, ep_dev->minor);
207 }
208 
209 static struct endpoint_class {
210 	struct kref kref;
211 	struct class *class;
212 } *ep_class;
213 
214 static int init_endpoint_class(void)
215 {
216 	int result = 0;
217 
218 	if (ep_class != NULL) {
219 		kref_get(&ep_class->kref);
220 		goto exit;
221 	}
222 
223 	ep_class = kmalloc(sizeof(*ep_class), GFP_KERNEL);
224 	if (!ep_class) {
225 		result = -ENOMEM;
226 		goto exit;
227 	}
228 
229 	kref_init(&ep_class->kref);
230 	ep_class->class = class_create(THIS_MODULE, "usb_endpoint");
231 	if (IS_ERR(ep_class->class)) {
232 		result = PTR_ERR(ep_class->class);
233 		goto class_create_error;
234 	}
235 
236 	result = usb_endpoint_major_init();
237 	if (result)
238 		goto endpoint_major_error;
239 
240 	goto exit;
241 
242 endpoint_major_error:
243 	class_destroy(ep_class->class);
244 class_create_error:
245 	kfree(ep_class);
246 	ep_class = NULL;
247 exit:
248 	return result;
249 }
250 
251 static void release_endpoint_class(struct kref *kref)
252 {
253 	/* Ok, we cheat as we know we only have one ep_class */
254 	class_destroy(ep_class->class);
255 	kfree(ep_class);
256 	ep_class = NULL;
257 	usb_endpoint_major_cleanup();
258 }
259 
260 static void destroy_endpoint_class(void)
261 {
262 	if (ep_class)
263 		kref_put(&ep_class->kref, release_endpoint_class);
264 }
265 
266 static void ep_device_release(struct device *dev)
267 {
268 	struct ep_device *ep_dev = to_ep_device(dev);
269 
270 	endpoint_free_minor(ep_dev);
271 	kfree(ep_dev);
272 }
273 
274 int usb_create_ep_files(struct device *parent,
275 			struct usb_host_endpoint *endpoint,
276 			struct usb_device *udev)
277 {
278 	char name[8];
279 	struct ep_device *ep_dev;
280 	int retval;
281 
282 	retval = init_endpoint_class();
283 	if (retval)
284 		goto exit;
285 
286 	ep_dev = kzalloc(sizeof(*ep_dev), GFP_KERNEL);
287 	if (!ep_dev) {
288 		retval = -ENOMEM;
289 		goto error_alloc;
290 	}
291 
292 	retval = endpoint_get_minor(ep_dev);
293 	if (retval) {
294 		dev_err(parent, "can not allocate minor number for %s\n",
295 			ep_dev->dev.bus_id);
296 		goto error_register;
297 	}
298 
299 	ep_dev->desc = &endpoint->desc;
300 	ep_dev->udev = udev;
301 	ep_dev->dev.devt = MKDEV(usb_endpoint_major, ep_dev->minor);
302 	ep_dev->dev.class = ep_class->class;
303 	ep_dev->dev.parent = parent;
304 	ep_dev->dev.release = ep_device_release;
305 	snprintf(ep_dev->dev.bus_id, BUS_ID_SIZE, "usbdev%d.%d_ep%02x",
306 		 udev->bus->busnum, udev->devnum,
307 		 endpoint->desc.bEndpointAddress);
308 
309 	retval = device_register(&ep_dev->dev);
310 	if (retval)
311 		goto error_chrdev;
312 	retval = sysfs_create_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
313 	if (retval)
314 		goto error_group;
315 
316 	/* create the symlink to the old-style "ep_XX" directory */
317 	sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
318 	retval = sysfs_create_link(&parent->kobj, &ep_dev->dev.kobj, name);
319 	if (retval)
320 		goto error_link;
321 	endpoint->ep_dev = ep_dev;
322 	return retval;
323 
324 error_link:
325 	sysfs_remove_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
326 error_group:
327 	device_unregister(&ep_dev->dev);
328 	destroy_endpoint_class();
329 	return retval;
330 
331 error_chrdev:
332 	endpoint_free_minor(ep_dev);
333 
334 error_register:
335 	kfree(ep_dev);
336 error_alloc:
337 	destroy_endpoint_class();
338 exit:
339 	return retval;
340 }
341 
342 void usb_remove_ep_files(struct usb_host_endpoint *endpoint)
343 {
344 	struct ep_device *ep_dev = endpoint->ep_dev;
345 
346 	if (ep_dev) {
347 		char name[8];
348 
349 		sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
350 		sysfs_remove_link(&ep_dev->dev.parent->kobj, name);
351 		sysfs_remove_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
352 		device_unregister(&ep_dev->dev);
353 		endpoint->ep_dev = NULL;
354 		destroy_endpoint_class();
355 	}
356 }
357