blob: c8e45add506e8db90ef8c8baa72dbc8947ea55d2 [file] [log] [blame]
Hans J. Kochbeafc542006-12-07 10:58:29 +01001/*
2 * drivers/uio/uio.c
3 *
4 * Copyright(C) 2005, Benedikt Spranger <b.spranger@linutronix.de>
5 * Copyright(C) 2005, Thomas Gleixner <tglx@linutronix.de>
Hans J. Koch318af552010-10-30 00:36:47 +02006 * Copyright(C) 2006, Hans J. Koch <hjk@hansjkoch.de>
Hans J. Kochbeafc542006-12-07 10:58:29 +01007 * Copyright(C) 2006, Greg Kroah-Hartman <greg@kroah.com>
8 *
9 * Userspace IO
10 *
11 * Base Functions
12 *
13 * Licensed under the GPLv2 only.
14 */
15
16#include <linux/module.h>
17#include <linux/init.h>
18#include <linux/poll.h>
19#include <linux/device.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090020#include <linux/slab.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010021#include <linux/mm.h>
22#include <linux/idr.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040023#include <linux/sched.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010024#include <linux/string.h>
25#include <linux/kobject.h>
Eric W. Biederman91960a42010-09-14 11:38:06 -070026#include <linux/cdev.h>
Hans J. Kochbeafc542006-12-07 10:58:29 +010027#include <linux/uio_driver.h>
28
Eric W. Biederman91960a42010-09-14 11:38:06 -070029#define UIO_MAX_DEVICES (1U << MINORBITS)
Hans J. Kochbeafc542006-12-07 10:58:29 +010030
31struct uio_device {
32 struct module *owner;
33 struct device *dev;
34 int minor;
35 atomic_t event;
36 struct fasync_struct *async_queue;
37 wait_queue_head_t wait;
Hans J. Kochbeafc542006-12-07 10:58:29 +010038 struct uio_info *info;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000039 struct kobject *map_dir;
Hans J. Koche70c4122008-12-06 02:23:13 +010040 struct kobject *portio_dir;
Hans J. Kochbeafc542006-12-07 10:58:29 +010041};
42
43static int uio_major;
Eric W. Biederman91960a42010-09-14 11:38:06 -070044static struct cdev *uio_cdev;
Hans J. Kochbeafc542006-12-07 10:58:29 +010045static DEFINE_IDR(uio_idr);
Jan Engelhardt4f014692008-01-22 20:50:54 +010046static const struct file_operations uio_fops;
Hans J. Kochbeafc542006-12-07 10:58:29 +010047
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -060048/* Protect idr accesses */
49static DEFINE_MUTEX(minor_lock);
50
Hans J. Kochbeafc542006-12-07 10:58:29 +010051/*
52 * attributes
53 */
54
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000055struct uio_map {
56 struct kobject kobj;
57 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010058};
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000059#define to_map(map) container_of(map, struct uio_map, kobj)
Hans J. Kochbeafc542006-12-07 10:58:29 +010060
Hans J. Koch82057792009-01-07 00:15:39 +010061static ssize_t map_name_show(struct uio_mem *mem, char *buf)
62{
63 if (unlikely(!mem->name))
64 mem->name = "";
65
66 return sprintf(buf, "%s\n", mem->name);
67}
68
Brandon Philips4f808bc2008-02-19 01:55:05 -080069static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
Hans J. Kochbeafc542006-12-07 10:58:29 +010070{
Kai Jiang27a90702011-10-17 20:50:20 +020071 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +010072}
73
Brandon Philips4f808bc2008-02-19 01:55:05 -080074static ssize_t map_size_show(struct uio_mem *mem, char *buf)
75{
76 return sprintf(buf, "0x%lx\n", mem->size);
77}
78
Hans J. Koche2b39df2008-09-18 23:53:18 +020079static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
80{
Kai Jiang27a90702011-10-17 20:50:20 +020081 return sprintf(buf, "0x%llx\n", (unsigned long long)mem->addr & ~PAGE_MASK);
Hans J. Koche2b39df2008-09-18 23:53:18 +020082}
83
Hans J. Koche70c4122008-12-06 02:23:13 +010084struct map_sysfs_entry {
Brandon Philips4f808bc2008-02-19 01:55:05 -080085 struct attribute attr;
86 ssize_t (*show)(struct uio_mem *, char *);
87 ssize_t (*store)(struct uio_mem *, const char *, size_t);
88};
89
Hans J. Koch82057792009-01-07 00:15:39 +010090static struct map_sysfs_entry name_attribute =
91 __ATTR(name, S_IRUGO, map_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010092static struct map_sysfs_entry addr_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080093 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010094static struct map_sysfs_entry size_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080095 __ATTR(size, S_IRUGO, map_size_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010096static struct map_sysfs_entry offset_attribute =
Hans J. Koche2b39df2008-09-18 23:53:18 +020097 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
Hans J. Kochbeafc542006-12-07 10:58:29 +010098
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000099static struct attribute *attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100100 &name_attribute.attr,
Brandon Philips4f808bc2008-02-19 01:55:05 -0800101 &addr_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000102 &size_attribute.attr,
Hans J. Koche2b39df2008-09-18 23:53:18 +0200103 &offset_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000104 NULL, /* need to NULL terminate the list of attributes */
Hans J. Kochbeafc542006-12-07 10:58:29 +0100105};
106
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000107static void map_release(struct kobject *kobj)
108{
109 struct uio_map *map = to_map(kobj);
110 kfree(map);
111}
112
Brandon Philips4f808bc2008-02-19 01:55:05 -0800113static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
114 char *buf)
115{
116 struct uio_map *map = to_map(kobj);
117 struct uio_mem *mem = map->mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100118 struct map_sysfs_entry *entry;
Brandon Philips4f808bc2008-02-19 01:55:05 -0800119
Hans J. Koche70c4122008-12-06 02:23:13 +0100120 entry = container_of(attr, struct map_sysfs_entry, attr);
Brandon Philips4f808bc2008-02-19 01:55:05 -0800121
122 if (!entry->show)
123 return -EIO;
124
125 return entry->show(mem, buf);
126}
127
Emese Revfy52cf25d2010-01-19 02:58:23 +0100128static const struct sysfs_ops map_sysfs_ops = {
Brandon Philips4f808bc2008-02-19 01:55:05 -0800129 .show = map_type_show,
130};
131
Hans J. Kochbeafc542006-12-07 10:58:29 +0100132static struct kobj_type map_attr_type = {
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000133 .release = map_release,
Hans J. Koche70c4122008-12-06 02:23:13 +0100134 .sysfs_ops = &map_sysfs_ops,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000135 .default_attrs = attrs,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100136};
137
Hans J. Koche70c4122008-12-06 02:23:13 +0100138struct uio_portio {
139 struct kobject kobj;
140 struct uio_port *port;
141};
142#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
143
Hans J. Koch82057792009-01-07 00:15:39 +0100144static ssize_t portio_name_show(struct uio_port *port, char *buf)
145{
146 if (unlikely(!port->name))
147 port->name = "";
148
149 return sprintf(buf, "%s\n", port->name);
150}
151
Hans J. Koche70c4122008-12-06 02:23:13 +0100152static ssize_t portio_start_show(struct uio_port *port, char *buf)
153{
154 return sprintf(buf, "0x%lx\n", port->start);
155}
156
157static ssize_t portio_size_show(struct uio_port *port, char *buf)
158{
159 return sprintf(buf, "0x%lx\n", port->size);
160}
161
162static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
163{
164 const char *porttypes[] = {"none", "x86", "gpio", "other"};
165
166 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
167 return -EINVAL;
168
169 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
170}
171
172struct portio_sysfs_entry {
173 struct attribute attr;
174 ssize_t (*show)(struct uio_port *, char *);
175 ssize_t (*store)(struct uio_port *, const char *, size_t);
176};
177
Hans J. Koch82057792009-01-07 00:15:39 +0100178static struct portio_sysfs_entry portio_name_attribute =
179 __ATTR(name, S_IRUGO, portio_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +0100180static struct portio_sysfs_entry portio_start_attribute =
181 __ATTR(start, S_IRUGO, portio_start_show, NULL);
182static struct portio_sysfs_entry portio_size_attribute =
183 __ATTR(size, S_IRUGO, portio_size_show, NULL);
184static struct portio_sysfs_entry portio_porttype_attribute =
185 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
186
187static struct attribute *portio_attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100188 &portio_name_attribute.attr,
Hans J. Koche70c4122008-12-06 02:23:13 +0100189 &portio_start_attribute.attr,
190 &portio_size_attribute.attr,
191 &portio_porttype_attribute.attr,
192 NULL,
193};
194
195static void portio_release(struct kobject *kobj)
196{
197 struct uio_portio *portio = to_portio(kobj);
198 kfree(portio);
199}
200
201static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
202 char *buf)
203{
204 struct uio_portio *portio = to_portio(kobj);
205 struct uio_port *port = portio->port;
206 struct portio_sysfs_entry *entry;
207
208 entry = container_of(attr, struct portio_sysfs_entry, attr);
209
210 if (!entry->show)
211 return -EIO;
212
213 return entry->show(port, buf);
214}
215
Emese Revfy52cf25d2010-01-19 02:58:23 +0100216static const struct sysfs_ops portio_sysfs_ops = {
Hans J. Koche70c4122008-12-06 02:23:13 +0100217 .show = portio_type_show,
218};
219
220static struct kobj_type portio_attr_type = {
221 .release = portio_release,
222 .sysfs_ops = &portio_sysfs_ops,
223 .default_attrs = portio_attrs,
224};
225
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700226static ssize_t name_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100227 struct device_attribute *attr, char *buf)
228{
229 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700230 return sprintf(buf, "%s\n", idev->info->name);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100231}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700232static DEVICE_ATTR_RO(name);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100233
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700234static ssize_t version_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100235 struct device_attribute *attr, char *buf)
236{
237 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700238 return sprintf(buf, "%s\n", idev->info->version);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100239}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700240static DEVICE_ATTR_RO(version);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100241
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700242static ssize_t event_show(struct device *dev,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100243 struct device_attribute *attr, char *buf)
244{
245 struct uio_device *idev = dev_get_drvdata(dev);
Eric W. Biederman70a91562010-09-14 11:36:54 -0700246 return sprintf(buf, "%u\n", (unsigned int)atomic_read(&idev->event));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100247}
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700248static DEVICE_ATTR_RO(event);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100249
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700250static struct attribute *uio_attrs[] = {
251 &dev_attr_name.attr,
252 &dev_attr_version.attr,
253 &dev_attr_event.attr,
254 NULL,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100255};
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700256ATTRIBUTE_GROUPS(uio);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100257
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700258/* UIO class infrastructure */
259static struct class uio_class = {
260 .name = "uio",
Greg Kroah-Hartmanc9dce922013-07-24 15:05:23 -0700261 .dev_groups = uio_groups,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100262};
263
264/*
265 * device functions
266 */
267static int uio_dev_add_attributes(struct uio_device *idev)
268{
269 int ret;
Hans J. Koche70c4122008-12-06 02:23:13 +0100270 int mi, pi;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100271 int map_found = 0;
Hans J. Koche70c4122008-12-06 02:23:13 +0100272 int portio_found = 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100273 struct uio_mem *mem;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000274 struct uio_map *map;
Hans J. Koche70c4122008-12-06 02:23:13 +0100275 struct uio_port *port;
276 struct uio_portio *portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100277
Hans J. Kochbeafc542006-12-07 10:58:29 +0100278 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
279 mem = &idev->info->mem[mi];
280 if (mem->size == 0)
281 break;
282 if (!map_found) {
283 map_found = 1;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000284 idev->map_dir = kobject_create_and_add("maps",
285 &idev->dev->kobj);
286 if (!idev->map_dir)
Hans J. Koche70c4122008-12-06 02:23:13 +0100287 goto err_map;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100288 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000289 map = kzalloc(sizeof(*map), GFP_KERNEL);
290 if (!map)
Cong Ding75f0aef2013-10-25 00:25:53 -0700291 goto err_map_kobj;
Greg Kroah-Hartmanf9cb0742007-12-17 23:05:35 -0700292 kobject_init(&map->kobj, &map_attr_type);
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000293 map->mem = mem;
294 mem->map = map;
Greg Kroah-Hartmanb2d6db52007-12-17 23:05:35 -0700295 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100296 if (ret)
Cong Ding75f0aef2013-10-25 00:25:53 -0700297 goto err_map_kobj;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000298 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
299 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100300 goto err_map;
301 }
302
303 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
304 port = &idev->info->port[pi];
305 if (port->size == 0)
306 break;
307 if (!portio_found) {
308 portio_found = 1;
309 idev->portio_dir = kobject_create_and_add("portio",
310 &idev->dev->kobj);
311 if (!idev->portio_dir)
312 goto err_portio;
313 }
314 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
315 if (!portio)
Cong Ding75f0aef2013-10-25 00:25:53 -0700316 goto err_portio_kobj;
Hans J. Koche70c4122008-12-06 02:23:13 +0100317 kobject_init(&portio->kobj, &portio_attr_type);
318 portio->port = port;
319 port->portio = portio;
320 ret = kobject_add(&portio->kobj, idev->portio_dir,
321 "port%d", pi);
322 if (ret)
Cong Ding75f0aef2013-10-25 00:25:53 -0700323 goto err_portio_kobj;
Hans J. Koche70c4122008-12-06 02:23:13 +0100324 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
325 if (ret)
326 goto err_portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100327 }
328
329 return 0;
330
Hans J. Koche70c4122008-12-06 02:23:13 +0100331err_portio:
Cong Ding75f0aef2013-10-25 00:25:53 -0700332 pi--;
333err_portio_kobj:
334 for (; pi >= 0; pi--) {
Hans J. Koche70c4122008-12-06 02:23:13 +0100335 port = &idev->info->port[pi];
336 portio = port->portio;
337 kobject_put(&portio->kobj);
338 }
339 kobject_put(idev->portio_dir);
340err_map:
Cong Ding75f0aef2013-10-25 00:25:53 -0700341 mi--;
342err_map_kobj:
343 for (; mi >= 0; mi--) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100344 mem = &idev->info->mem[mi];
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000345 map = mem->map;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800346 kobject_put(&map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100347 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800348 kobject_put(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100349 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
350 return ret;
351}
352
353static void uio_dev_del_attributes(struct uio_device *idev)
354{
Hans J. Koche70c4122008-12-06 02:23:13 +0100355 int i;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100356 struct uio_mem *mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100357 struct uio_port *port;
358
359 for (i = 0; i < MAX_UIO_MAPS; i++) {
360 mem = &idev->info->mem[i];
Hans J. Kochbeafc542006-12-07 10:58:29 +0100361 if (mem->size == 0)
362 break;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800363 kobject_put(&mem->map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100364 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800365 kobject_put(idev->map_dir);
Hans J. Koche70c4122008-12-06 02:23:13 +0100366
367 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
368 port = &idev->info->port[i];
369 if (port->size == 0)
370 break;
371 kobject_put(&port->portio->kobj);
372 }
373 kobject_put(idev->portio_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100374}
375
376static int uio_get_minor(struct uio_device *idev)
377{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100378 int retval = -ENOMEM;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100379
380 mutex_lock(&minor_lock);
Tejun Heo6d770932013-02-27 17:04:47 -0800381 retval = idr_alloc(&uio_idr, idev, 0, UIO_MAX_DEVICES, GFP_KERNEL);
382 if (retval >= 0) {
383 idev->minor = retval;
Damian Hobson-Garcia5ed05052013-03-26 10:31:22 +0900384 retval = 0;
Tejun Heo6d770932013-02-27 17:04:47 -0800385 } else if (retval == -ENOSPC) {
Hillf Dantonc6edc422011-03-31 20:38:47 +0800386 dev_err(idev->dev, "too many uio devices\n");
387 retval = -EINVAL;
Hillf Dantonc6edc422011-03-31 20:38:47 +0800388 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100389 mutex_unlock(&minor_lock);
390 return retval;
391}
392
393static void uio_free_minor(struct uio_device *idev)
394{
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600395 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100396 idr_remove(&uio_idr, idev->minor);
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600397 mutex_unlock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100398}
399
400/**
401 * uio_event_notify - trigger an interrupt event
402 * @info: UIO device capabilities
403 */
404void uio_event_notify(struct uio_info *info)
405{
406 struct uio_device *idev = info->uio_dev;
407
408 atomic_inc(&idev->event);
409 wake_up_interruptible(&idev->wait);
410 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
411}
412EXPORT_SYMBOL_GPL(uio_event_notify);
413
414/**
415 * uio_interrupt - hardware interrupt handler
416 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
417 * @dev_id: Pointer to the devices uio_device structure
418 */
419static irqreturn_t uio_interrupt(int irq, void *dev_id)
420{
421 struct uio_device *idev = (struct uio_device *)dev_id;
422 irqreturn_t ret = idev->info->handler(irq, idev->info);
423
424 if (ret == IRQ_HANDLED)
425 uio_event_notify(idev->info);
426
427 return ret;
428}
429
430struct uio_listener {
431 struct uio_device *dev;
432 s32 event_count;
433};
434
435static int uio_open(struct inode *inode, struct file *filep)
436{
437 struct uio_device *idev;
438 struct uio_listener *listener;
439 int ret = 0;
440
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600441 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100442 idev = idr_find(&uio_idr, iminor(inode));
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600443 mutex_unlock(&minor_lock);
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600444 if (!idev) {
445 ret = -ENODEV;
446 goto out;
447 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100448
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600449 if (!try_module_get(idev->owner)) {
450 ret = -ENODEV;
451 goto out;
452 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200453
Hans J. Kochbeafc542006-12-07 10:58:29 +0100454 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200455 if (!listener) {
456 ret = -ENOMEM;
457 goto err_alloc_listener;
458 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100459
460 listener->dev = idev;
461 listener->event_count = atomic_read(&idev->event);
462 filep->private_data = listener;
463
464 if (idev->info->open) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100465 ret = idev->info->open(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200466 if (ret)
467 goto err_infoopen;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100468 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200469 return 0;
470
471err_infoopen:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200472 kfree(listener);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200473
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600474err_alloc_listener:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200475 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100476
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600477out:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100478 return ret;
479}
480
481static int uio_fasync(int fd, struct file *filep, int on)
482{
483 struct uio_listener *listener = filep->private_data;
484 struct uio_device *idev = listener->dev;
485
486 return fasync_helper(fd, filep, on, &idev->async_queue);
487}
488
489static int uio_release(struct inode *inode, struct file *filep)
490{
491 int ret = 0;
492 struct uio_listener *listener = filep->private_data;
493 struct uio_device *idev = listener->dev;
494
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200495 if (idev->info->release)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100496 ret = idev->info->release(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200497
498 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100499 kfree(listener);
500 return ret;
501}
502
503static unsigned int uio_poll(struct file *filep, poll_table *wait)
504{
505 struct uio_listener *listener = filep->private_data;
506 struct uio_device *idev = listener->dev;
507
Eric W. Biederman6427a762010-09-14 11:37:36 -0700508 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100509 return -EIO;
510
511 poll_wait(filep, &idev->wait, wait);
512 if (listener->event_count != atomic_read(&idev->event))
513 return POLLIN | POLLRDNORM;
514 return 0;
515}
516
517static ssize_t uio_read(struct file *filep, char __user *buf,
518 size_t count, loff_t *ppos)
519{
520 struct uio_listener *listener = filep->private_data;
521 struct uio_device *idev = listener->dev;
522 DECLARE_WAITQUEUE(wait, current);
523 ssize_t retval;
524 s32 event_count;
525
Eric W. Biederman6427a762010-09-14 11:37:36 -0700526 if (!idev->info->irq)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100527 return -EIO;
528
529 if (count != sizeof(s32))
530 return -EINVAL;
531
532 add_wait_queue(&idev->wait, &wait);
533
534 do {
535 set_current_state(TASK_INTERRUPTIBLE);
536
537 event_count = atomic_read(&idev->event);
538 if (event_count != listener->event_count) {
539 if (copy_to_user(buf, &event_count, count))
540 retval = -EFAULT;
541 else {
542 listener->event_count = event_count;
543 retval = count;
544 }
545 break;
546 }
547
548 if (filep->f_flags & O_NONBLOCK) {
549 retval = -EAGAIN;
550 break;
551 }
552
553 if (signal_pending(current)) {
554 retval = -ERESTARTSYS;
555 break;
556 }
557 schedule();
558 } while (1);
559
560 __set_current_state(TASK_RUNNING);
561 remove_wait_queue(&idev->wait, &wait);
562
563 return retval;
564}
565
Hans J. Koch328a14e2008-05-23 13:50:14 +0200566static ssize_t uio_write(struct file *filep, const char __user *buf,
567 size_t count, loff_t *ppos)
568{
569 struct uio_listener *listener = filep->private_data;
570 struct uio_device *idev = listener->dev;
571 ssize_t retval;
572 s32 irq_on;
573
Eric W. Biederman6427a762010-09-14 11:37:36 -0700574 if (!idev->info->irq)
Hans J. Koch328a14e2008-05-23 13:50:14 +0200575 return -EIO;
576
577 if (count != sizeof(s32))
578 return -EINVAL;
579
580 if (!idev->info->irqcontrol)
581 return -ENOSYS;
582
583 if (copy_from_user(&irq_on, buf, count))
584 return -EFAULT;
585
586 retval = idev->info->irqcontrol(idev->info, irq_on);
587
588 return retval ? retval : sizeof(s32);
589}
590
Hans J. Kochbeafc542006-12-07 10:58:29 +0100591static int uio_find_mem_index(struct vm_area_struct *vma)
592{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100593 struct uio_device *idev = vma->vm_private_data;
594
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200595 if (vma->vm_pgoff < MAX_UIO_MAPS) {
596 if (idev->info->mem[vma->vm_pgoff].size == 0)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100597 return -1;
Hillf Dantonf0c554f2011-03-28 23:33:26 +0200598 return (int)vma->vm_pgoff;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100599 }
600 return -1;
601}
602
Nick Piggina18b6302008-02-06 01:37:35 -0800603static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100604{
605 struct uio_device *idev = vma->vm_private_data;
Nick Piggina18b6302008-02-06 01:37:35 -0800606 struct page *page;
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200607 unsigned long offset;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100608
609 int mi = uio_find_mem_index(vma);
610 if (mi < 0)
Nick Piggina18b6302008-02-06 01:37:35 -0800611 return VM_FAULT_SIGBUS;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100612
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200613 /*
614 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
615 * to use mem[N].
616 */
617 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
618
Hans J. Kochbeafc542006-12-07 10:58:29 +0100619 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200620 page = virt_to_page(idev->info->mem[mi].addr + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100621 else
Kai Jiang27a90702011-10-17 20:50:20 +0200622 page = vmalloc_to_page((void *)(unsigned long)idev->info->mem[mi].addr + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100623 get_page(page);
Nick Piggina18b6302008-02-06 01:37:35 -0800624 vmf->page = page;
625 return 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100626}
627
Uwe Kleine-König72941512013-08-07 13:02:53 +0200628static const struct vm_operations_struct uio_logical_vm_ops = {
Nick Piggina18b6302008-02-06 01:37:35 -0800629 .fault = uio_vma_fault,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100630};
631
Uwe Kleine-König72941512013-08-07 13:02:53 +0200632static int uio_mmap_logical(struct vm_area_struct *vma)
633{
634 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
635 vma->vm_ops = &uio_logical_vm_ops;
Uwe Kleine-König72941512013-08-07 13:02:53 +0200636 return 0;
637}
638
639static const struct vm_operations_struct uio_physical_vm_ops = {
640#ifdef CONFIG_HAVE_IOREMAP_PROT
641 .access = generic_access_phys,
642#endif
643};
644
Hans J. Kochbeafc542006-12-07 10:58:29 +0100645static int uio_mmap_physical(struct vm_area_struct *vma)
646{
647 struct uio_device *idev = vma->vm_private_data;
648 int mi = uio_find_mem_index(vma);
649 if (mi < 0)
650 return -EINVAL;
651
Uwe Kleine-König72941512013-08-07 13:02:53 +0200652 vma->vm_ops = &uio_physical_vm_ops;
653
Jean-Samuel Chenardc9698d6b2008-03-14 11:28:36 +0100654 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
655
Hans J. Kochbeafc542006-12-07 10:58:29 +0100656 return remap_pfn_range(vma,
657 vma->vm_start,
658 idev->info->mem[mi].addr >> PAGE_SHIFT,
659 vma->vm_end - vma->vm_start,
660 vma->vm_page_prot);
661}
662
Hans J. Kochbeafc542006-12-07 10:58:29 +0100663static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
664{
665 struct uio_listener *listener = filep->private_data;
666 struct uio_device *idev = listener->dev;
667 int mi;
668 unsigned long requested_pages, actual_pages;
669 int ret = 0;
670
671 if (vma->vm_end < vma->vm_start)
672 return -EINVAL;
673
674 vma->vm_private_data = idev;
675
676 mi = uio_find_mem_index(vma);
677 if (mi < 0)
678 return -EINVAL;
679
Libin52c2dad2013-07-03 15:01:27 -0700680 requested_pages = vma_pages(vma);
Ian Abbott6da2d372009-02-24 17:22:59 +0000681 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
682 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100683 if (requested_pages > actual_pages)
684 return -EINVAL;
685
686 if (idev->info->mmap) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100687 ret = idev->info->mmap(idev->info, vma);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100688 return ret;
689 }
690
691 switch (idev->info->mem[mi].memtype) {
692 case UIO_MEM_PHYS:
693 return uio_mmap_physical(vma);
694 case UIO_MEM_LOGICAL:
695 case UIO_MEM_VIRTUAL:
696 return uio_mmap_logical(vma);
697 default:
698 return -EINVAL;
699 }
700}
701
Jan Engelhardt4f014692008-01-22 20:50:54 +0100702static const struct file_operations uio_fops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100703 .owner = THIS_MODULE,
704 .open = uio_open,
705 .release = uio_release,
706 .read = uio_read,
Hans J. Koch328a14e2008-05-23 13:50:14 +0200707 .write = uio_write,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100708 .mmap = uio_mmap,
709 .poll = uio_poll,
710 .fasync = uio_fasync,
Arnd Bergmann6038f372010-08-15 18:52:59 +0200711 .llseek = noop_llseek,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100712};
713
714static int uio_major_init(void)
715{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700716 static const char name[] = "uio";
717 struct cdev *cdev = NULL;
718 dev_t uio_dev = 0;
719 int result;
720
721 result = alloc_chrdev_region(&uio_dev, 0, UIO_MAX_DEVICES, name);
722 if (result)
723 goto out;
724
725 result = -ENOMEM;
726 cdev = cdev_alloc();
727 if (!cdev)
728 goto out_unregister;
729
730 cdev->owner = THIS_MODULE;
731 cdev->ops = &uio_fops;
732 kobject_set_name(&cdev->kobj, "%s", name);
733
734 result = cdev_add(cdev, uio_dev, UIO_MAX_DEVICES);
735 if (result)
736 goto out_put;
737
738 uio_major = MAJOR(uio_dev);
739 uio_cdev = cdev;
Wanlong Gaod80df1c2011-08-20 12:12:08 +0800740 return 0;
Eric W. Biederman91960a42010-09-14 11:38:06 -0700741out_put:
742 kobject_put(&cdev->kobj);
743out_unregister:
744 unregister_chrdev_region(uio_dev, UIO_MAX_DEVICES);
Wanlong Gaod80df1c2011-08-20 12:12:08 +0800745out:
746 return result;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100747}
748
749static void uio_major_cleanup(void)
750{
Eric W. Biederman91960a42010-09-14 11:38:06 -0700751 unregister_chrdev_region(MKDEV(uio_major, 0), UIO_MAX_DEVICES);
752 cdev_del(uio_cdev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100753}
754
755static int init_uio_class(void)
756{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700757 int ret;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100758
759 /* This is the first time in here, set everything up properly */
760 ret = uio_major_init();
761 if (ret)
762 goto exit;
763
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700764 ret = class_register(&uio_class);
765 if (ret) {
766 printk(KERN_ERR "class_register failed for uio\n");
767 goto err_class_register;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100768 }
769 return 0;
770
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700771err_class_register:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100772 uio_major_cleanup();
773exit:
774 return ret;
775}
776
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700777static void release_uio_class(void)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100778{
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700779 class_unregister(&uio_class);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100780 uio_major_cleanup();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100781}
782
783/**
784 * uio_register_device - register a new userspace IO device
785 * @owner: module that creates the new device
786 * @parent: parent device
787 * @info: UIO device capabilities
788 *
789 * returns zero on success or a negative error code.
790 */
791int __uio_register_device(struct module *owner,
792 struct device *parent,
793 struct uio_info *info)
794{
795 struct uio_device *idev;
796 int ret = 0;
797
798 if (!parent || !info || !info->name || !info->version)
799 return -EINVAL;
800
801 info->uio_dev = NULL;
802
Michal Simeke6789cd2013-09-12 07:39:59 +0200803 idev = devm_kzalloc(parent, sizeof(*idev), GFP_KERNEL);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100804 if (!idev) {
Michal Simeke6789cd2013-09-12 07:39:59 +0200805 return -ENOMEM;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100806 }
807
808 idev->owner = owner;
809 idev->info = info;
810 init_waitqueue_head(&idev->wait);
811 atomic_set(&idev->event, 0);
812
813 ret = uio_get_minor(idev);
814 if (ret)
Michal Simeke6789cd2013-09-12 07:39:59 +0200815 return ret;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100816
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700817 idev->dev = device_create(&uio_class, parent,
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700818 MKDEV(uio_major, idev->minor), idev,
819 "uio%d", idev->minor);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100820 if (IS_ERR(idev->dev)) {
821 printk(KERN_ERR "UIO: device register failed\n");
822 ret = PTR_ERR(idev->dev);
823 goto err_device_create;
824 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100825
826 ret = uio_dev_add_attributes(idev);
827 if (ret)
828 goto err_uio_dev_add_attributes;
829
830 info->uio_dev = idev;
831
Eric W. Biederman6427a762010-09-14 11:37:36 -0700832 if (info->irq && (info->irq != UIO_IRQ_CUSTOM)) {
Michal Simeke6789cd2013-09-12 07:39:59 +0200833 ret = devm_request_irq(parent, info->irq, uio_interrupt,
Eric W. Biederman6427a762010-09-14 11:37:36 -0700834 info->irq_flags, info->name, idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100835 if (ret)
836 goto err_request_irq;
837 }
838
839 return 0;
840
841err_request_irq:
842 uio_dev_del_attributes(idev);
843err_uio_dev_add_attributes:
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700844 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100845err_device_create:
846 uio_free_minor(idev);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100847 return ret;
848}
849EXPORT_SYMBOL_GPL(__uio_register_device);
850
851/**
852 * uio_unregister_device - unregister a industrial IO device
853 * @info: UIO device capabilities
854 *
855 */
856void uio_unregister_device(struct uio_info *info)
857{
858 struct uio_device *idev;
859
860 if (!info || !info->uio_dev)
861 return;
862
863 idev = info->uio_dev;
864
865 uio_free_minor(idev);
866
Hans J. Kochbeafc542006-12-07 10:58:29 +0100867 uio_dev_del_attributes(idev);
868
Eric W. Biedermanc66fdab2010-09-14 11:38:36 -0700869 device_destroy(&uio_class, MKDEV(uio_major, idev->minor));
Hans J. Kochbeafc542006-12-07 10:58:29 +0100870
871 return;
872}
873EXPORT_SYMBOL_GPL(uio_unregister_device);
874
875static int __init uio_init(void)
876{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700877 return init_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100878}
879
880static void __exit uio_exit(void)
881{
Eric W. Biederman3d4f9d72010-09-14 11:36:27 -0700882 release_uio_class();
Hans J. Kochbeafc542006-12-07 10:58:29 +0100883}
884
885module_init(uio_init)
886module_exit(uio_exit)
887MODULE_LICENSE("GPL v2");