blob: bff1afbde5a4b0ad01d0314b1661d43c972c3d84 [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>
6 * Copyright(C) 2006, Hans J. Koch <hjk@linutronix.de>
7 * 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>
26#include <linux/uio_driver.h>
27
28#define UIO_MAX_DEVICES 255
29
30struct uio_device {
31 struct module *owner;
32 struct device *dev;
33 int minor;
34 atomic_t event;
35 struct fasync_struct *async_queue;
36 wait_queue_head_t wait;
37 int vma_count;
38 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;
44static DEFINE_IDR(uio_idr);
Jan Engelhardt4f014692008-01-22 20:50:54 +010045static const struct file_operations uio_fops;
Hans J. Kochbeafc542006-12-07 10:58:29 +010046
47/* UIO class infrastructure */
48static struct uio_class {
49 struct kref kref;
50 struct class *class;
51} *uio_class;
52
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -060053/* Protect idr accesses */
54static DEFINE_MUTEX(minor_lock);
55
Hans J. Kochbeafc542006-12-07 10:58:29 +010056/*
57 * attributes
58 */
59
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000060struct uio_map {
61 struct kobject kobj;
62 struct uio_mem *mem;
Hans J. Kochbeafc542006-12-07 10:58:29 +010063};
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +000064#define to_map(map) container_of(map, struct uio_map, kobj)
Hans J. Kochbeafc542006-12-07 10:58:29 +010065
Hans J. Koch82057792009-01-07 00:15:39 +010066static ssize_t map_name_show(struct uio_mem *mem, char *buf)
67{
68 if (unlikely(!mem->name))
69 mem->name = "";
70
71 return sprintf(buf, "%s\n", mem->name);
72}
73
Brandon Philips4f808bc2008-02-19 01:55:05 -080074static ssize_t map_addr_show(struct uio_mem *mem, char *buf)
Hans J. Kochbeafc542006-12-07 10:58:29 +010075{
Brandon Philips4f808bc2008-02-19 01:55:05 -080076 return sprintf(buf, "0x%lx\n", mem->addr);
Hans J. Kochbeafc542006-12-07 10:58:29 +010077}
78
Brandon Philips4f808bc2008-02-19 01:55:05 -080079static ssize_t map_size_show(struct uio_mem *mem, char *buf)
80{
81 return sprintf(buf, "0x%lx\n", mem->size);
82}
83
Hans J. Koche2b39df2008-09-18 23:53:18 +020084static ssize_t map_offset_show(struct uio_mem *mem, char *buf)
85{
86 return sprintf(buf, "0x%lx\n", mem->addr & ~PAGE_MASK);
87}
88
Hans J. Koche70c4122008-12-06 02:23:13 +010089struct map_sysfs_entry {
Brandon Philips4f808bc2008-02-19 01:55:05 -080090 struct attribute attr;
91 ssize_t (*show)(struct uio_mem *, char *);
92 ssize_t (*store)(struct uio_mem *, const char *, size_t);
93};
94
Hans J. Koch82057792009-01-07 00:15:39 +010095static struct map_sysfs_entry name_attribute =
96 __ATTR(name, S_IRUGO, map_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010097static struct map_sysfs_entry addr_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -080098 __ATTR(addr, S_IRUGO, map_addr_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +010099static struct map_sysfs_entry size_attribute =
Brandon Philips4f808bc2008-02-19 01:55:05 -0800100 __ATTR(size, S_IRUGO, map_size_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +0100101static struct map_sysfs_entry offset_attribute =
Hans J. Koche2b39df2008-09-18 23:53:18 +0200102 __ATTR(offset, S_IRUGO, map_offset_show, NULL);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100103
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000104static struct attribute *attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100105 &name_attribute.attr,
Brandon Philips4f808bc2008-02-19 01:55:05 -0800106 &addr_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000107 &size_attribute.attr,
Hans J. Koche2b39df2008-09-18 23:53:18 +0200108 &offset_attribute.attr,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000109 NULL, /* need to NULL terminate the list of attributes */
Hans J. Kochbeafc542006-12-07 10:58:29 +0100110};
111
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000112static void map_release(struct kobject *kobj)
113{
114 struct uio_map *map = to_map(kobj);
115 kfree(map);
116}
117
Brandon Philips4f808bc2008-02-19 01:55:05 -0800118static ssize_t map_type_show(struct kobject *kobj, struct attribute *attr,
119 char *buf)
120{
121 struct uio_map *map = to_map(kobj);
122 struct uio_mem *mem = map->mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100123 struct map_sysfs_entry *entry;
Brandon Philips4f808bc2008-02-19 01:55:05 -0800124
Hans J. Koche70c4122008-12-06 02:23:13 +0100125 entry = container_of(attr, struct map_sysfs_entry, attr);
Brandon Philips4f808bc2008-02-19 01:55:05 -0800126
127 if (!entry->show)
128 return -EIO;
129
130 return entry->show(mem, buf);
131}
132
Emese Revfy52cf25d2010-01-19 02:58:23 +0100133static const struct sysfs_ops map_sysfs_ops = {
Brandon Philips4f808bc2008-02-19 01:55:05 -0800134 .show = map_type_show,
135};
136
Hans J. Kochbeafc542006-12-07 10:58:29 +0100137static struct kobj_type map_attr_type = {
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000138 .release = map_release,
Hans J. Koche70c4122008-12-06 02:23:13 +0100139 .sysfs_ops = &map_sysfs_ops,
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000140 .default_attrs = attrs,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100141};
142
Hans J. Koche70c4122008-12-06 02:23:13 +0100143struct uio_portio {
144 struct kobject kobj;
145 struct uio_port *port;
146};
147#define to_portio(portio) container_of(portio, struct uio_portio, kobj)
148
Hans J. Koch82057792009-01-07 00:15:39 +0100149static ssize_t portio_name_show(struct uio_port *port, char *buf)
150{
151 if (unlikely(!port->name))
152 port->name = "";
153
154 return sprintf(buf, "%s\n", port->name);
155}
156
Hans J. Koche70c4122008-12-06 02:23:13 +0100157static ssize_t portio_start_show(struct uio_port *port, char *buf)
158{
159 return sprintf(buf, "0x%lx\n", port->start);
160}
161
162static ssize_t portio_size_show(struct uio_port *port, char *buf)
163{
164 return sprintf(buf, "0x%lx\n", port->size);
165}
166
167static ssize_t portio_porttype_show(struct uio_port *port, char *buf)
168{
169 const char *porttypes[] = {"none", "x86", "gpio", "other"};
170
171 if ((port->porttype < 0) || (port->porttype > UIO_PORT_OTHER))
172 return -EINVAL;
173
174 return sprintf(buf, "port_%s\n", porttypes[port->porttype]);
175}
176
177struct portio_sysfs_entry {
178 struct attribute attr;
179 ssize_t (*show)(struct uio_port *, char *);
180 ssize_t (*store)(struct uio_port *, const char *, size_t);
181};
182
Hans J. Koch82057792009-01-07 00:15:39 +0100183static struct portio_sysfs_entry portio_name_attribute =
184 __ATTR(name, S_IRUGO, portio_name_show, NULL);
Hans J. Koche70c4122008-12-06 02:23:13 +0100185static struct portio_sysfs_entry portio_start_attribute =
186 __ATTR(start, S_IRUGO, portio_start_show, NULL);
187static struct portio_sysfs_entry portio_size_attribute =
188 __ATTR(size, S_IRUGO, portio_size_show, NULL);
189static struct portio_sysfs_entry portio_porttype_attribute =
190 __ATTR(porttype, S_IRUGO, portio_porttype_show, NULL);
191
192static struct attribute *portio_attrs[] = {
Hans J. Koch82057792009-01-07 00:15:39 +0100193 &portio_name_attribute.attr,
Hans J. Koche70c4122008-12-06 02:23:13 +0100194 &portio_start_attribute.attr,
195 &portio_size_attribute.attr,
196 &portio_porttype_attribute.attr,
197 NULL,
198};
199
200static void portio_release(struct kobject *kobj)
201{
202 struct uio_portio *portio = to_portio(kobj);
203 kfree(portio);
204}
205
206static ssize_t portio_type_show(struct kobject *kobj, struct attribute *attr,
207 char *buf)
208{
209 struct uio_portio *portio = to_portio(kobj);
210 struct uio_port *port = portio->port;
211 struct portio_sysfs_entry *entry;
212
213 entry = container_of(attr, struct portio_sysfs_entry, attr);
214
215 if (!entry->show)
216 return -EIO;
217
218 return entry->show(port, buf);
219}
220
Emese Revfy52cf25d2010-01-19 02:58:23 +0100221static const struct sysfs_ops portio_sysfs_ops = {
Hans J. Koche70c4122008-12-06 02:23:13 +0100222 .show = portio_type_show,
223};
224
225static struct kobj_type portio_attr_type = {
226 .release = portio_release,
227 .sysfs_ops = &portio_sysfs_ops,
228 .default_attrs = portio_attrs,
229};
230
Hans J. Kochbeafc542006-12-07 10:58:29 +0100231static ssize_t show_name(struct device *dev,
232 struct device_attribute *attr, char *buf)
233{
234 struct uio_device *idev = dev_get_drvdata(dev);
235 if (idev)
236 return sprintf(buf, "%s\n", idev->info->name);
237 else
238 return -ENODEV;
239}
240static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
241
242static ssize_t show_version(struct device *dev,
243 struct device_attribute *attr, char *buf)
244{
245 struct uio_device *idev = dev_get_drvdata(dev);
246 if (idev)
247 return sprintf(buf, "%s\n", idev->info->version);
248 else
249 return -ENODEV;
250}
251static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
252
253static ssize_t show_event(struct device *dev,
254 struct device_attribute *attr, char *buf)
255{
256 struct uio_device *idev = dev_get_drvdata(dev);
257 if (idev)
258 return sprintf(buf, "%u\n",
259 (unsigned int)atomic_read(&idev->event));
260 else
261 return -ENODEV;
262}
263static DEVICE_ATTR(event, S_IRUGO, show_event, NULL);
264
265static struct attribute *uio_attrs[] = {
266 &dev_attr_name.attr,
267 &dev_attr_version.attr,
268 &dev_attr_event.attr,
269 NULL,
270};
271
272static struct attribute_group uio_attr_grp = {
273 .attrs = uio_attrs,
274};
275
276/*
277 * device functions
278 */
279static int uio_dev_add_attributes(struct uio_device *idev)
280{
281 int ret;
Hans J. Koche70c4122008-12-06 02:23:13 +0100282 int mi, pi;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100283 int map_found = 0;
Hans J. Koche70c4122008-12-06 02:23:13 +0100284 int portio_found = 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100285 struct uio_mem *mem;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000286 struct uio_map *map;
Hans J. Koche70c4122008-12-06 02:23:13 +0100287 struct uio_port *port;
288 struct uio_portio *portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100289
290 ret = sysfs_create_group(&idev->dev->kobj, &uio_attr_grp);
291 if (ret)
292 goto err_group;
293
294 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
295 mem = &idev->info->mem[mi];
296 if (mem->size == 0)
297 break;
298 if (!map_found) {
299 map_found = 1;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000300 idev->map_dir = kobject_create_and_add("maps",
301 &idev->dev->kobj);
302 if (!idev->map_dir)
Hans J. Koche70c4122008-12-06 02:23:13 +0100303 goto err_map;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100304 }
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000305 map = kzalloc(sizeof(*map), GFP_KERNEL);
306 if (!map)
Hans J. Koche70c4122008-12-06 02:23:13 +0100307 goto err_map;
Greg Kroah-Hartmanf9cb0742007-12-17 23:05:35 -0700308 kobject_init(&map->kobj, &map_attr_type);
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000309 map->mem = mem;
310 mem->map = map;
Greg Kroah-Hartmanb2d6db52007-12-17 23:05:35 -0700311 ret = kobject_add(&map->kobj, idev->map_dir, "map%d", mi);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100312 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100313 goto err_map;
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000314 ret = kobject_uevent(&map->kobj, KOBJ_ADD);
315 if (ret)
Hans J. Koche70c4122008-12-06 02:23:13 +0100316 goto err_map;
317 }
318
319 for (pi = 0; pi < MAX_UIO_PORT_REGIONS; pi++) {
320 port = &idev->info->port[pi];
321 if (port->size == 0)
322 break;
323 if (!portio_found) {
324 portio_found = 1;
325 idev->portio_dir = kobject_create_and_add("portio",
326 &idev->dev->kobj);
327 if (!idev->portio_dir)
328 goto err_portio;
329 }
330 portio = kzalloc(sizeof(*portio), GFP_KERNEL);
331 if (!portio)
332 goto err_portio;
333 kobject_init(&portio->kobj, &portio_attr_type);
334 portio->port = port;
335 port->portio = portio;
336 ret = kobject_add(&portio->kobj, idev->portio_dir,
337 "port%d", pi);
338 if (ret)
339 goto err_portio;
340 ret = kobject_uevent(&portio->kobj, KOBJ_ADD);
341 if (ret)
342 goto err_portio;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100343 }
344
345 return 0;
346
Hans J. Koche70c4122008-12-06 02:23:13 +0100347err_portio:
348 for (pi--; pi >= 0; pi--) {
349 port = &idev->info->port[pi];
350 portio = port->portio;
351 kobject_put(&portio->kobj);
352 }
353 kobject_put(idev->portio_dir);
354err_map:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100355 for (mi--; mi>=0; mi--) {
356 mem = &idev->info->mem[mi];
Greg Kroah-Hartman81e7c6a2007-12-04 22:41:54 +0000357 map = mem->map;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800358 kobject_put(&map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100359 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800360 kobject_put(idev->map_dir);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100361 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
362err_group:
363 dev_err(idev->dev, "error creating sysfs files (%d)\n", ret);
364 return ret;
365}
366
367static void uio_dev_del_attributes(struct uio_device *idev)
368{
Hans J. Koche70c4122008-12-06 02:23:13 +0100369 int i;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100370 struct uio_mem *mem;
Hans J. Koche70c4122008-12-06 02:23:13 +0100371 struct uio_port *port;
372
373 for (i = 0; i < MAX_UIO_MAPS; i++) {
374 mem = &idev->info->mem[i];
Hans J. Kochbeafc542006-12-07 10:58:29 +0100375 if (mem->size == 0)
376 break;
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800377 kobject_put(&mem->map->kobj);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100378 }
Greg Kroah-Hartmanc10997f2007-12-20 08:13:05 -0800379 kobject_put(idev->map_dir);
Hans J. Koche70c4122008-12-06 02:23:13 +0100380
381 for (i = 0; i < MAX_UIO_PORT_REGIONS; i++) {
382 port = &idev->info->port[i];
383 if (port->size == 0)
384 break;
385 kobject_put(&port->portio->kobj);
386 }
387 kobject_put(idev->portio_dir);
388
Hans J. Kochbeafc542006-12-07 10:58:29 +0100389 sysfs_remove_group(&idev->dev->kobj, &uio_attr_grp);
390}
391
392static int uio_get_minor(struct uio_device *idev)
393{
Hans J. Kochbeafc542006-12-07 10:58:29 +0100394 int retval = -ENOMEM;
395 int id;
396
397 mutex_lock(&minor_lock);
398 if (idr_pre_get(&uio_idr, GFP_KERNEL) == 0)
399 goto exit;
400
401 retval = idr_get_new(&uio_idr, idev, &id);
402 if (retval < 0) {
403 if (retval == -EAGAIN)
404 retval = -ENOMEM;
405 goto exit;
406 }
407 idev->minor = id & MAX_ID_MASK;
408exit:
409 mutex_unlock(&minor_lock);
410 return retval;
411}
412
413static void uio_free_minor(struct uio_device *idev)
414{
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600415 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100416 idr_remove(&uio_idr, idev->minor);
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600417 mutex_unlock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100418}
419
420/**
421 * uio_event_notify - trigger an interrupt event
422 * @info: UIO device capabilities
423 */
424void uio_event_notify(struct uio_info *info)
425{
426 struct uio_device *idev = info->uio_dev;
427
428 atomic_inc(&idev->event);
429 wake_up_interruptible(&idev->wait);
430 kill_fasync(&idev->async_queue, SIGIO, POLL_IN);
431}
432EXPORT_SYMBOL_GPL(uio_event_notify);
433
434/**
435 * uio_interrupt - hardware interrupt handler
436 * @irq: IRQ number, can be UIO_IRQ_CYCLIC for cyclic timer
437 * @dev_id: Pointer to the devices uio_device structure
438 */
439static irqreturn_t uio_interrupt(int irq, void *dev_id)
440{
441 struct uio_device *idev = (struct uio_device *)dev_id;
442 irqreturn_t ret = idev->info->handler(irq, idev->info);
443
444 if (ret == IRQ_HANDLED)
445 uio_event_notify(idev->info);
446
447 return ret;
448}
449
450struct uio_listener {
451 struct uio_device *dev;
452 s32 event_count;
453};
454
455static int uio_open(struct inode *inode, struct file *filep)
456{
457 struct uio_device *idev;
458 struct uio_listener *listener;
459 int ret = 0;
460
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600461 mutex_lock(&minor_lock);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100462 idev = idr_find(&uio_idr, iminor(inode));
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600463 mutex_unlock(&minor_lock);
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600464 if (!idev) {
465 ret = -ENODEV;
466 goto out;
467 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100468
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600469 if (!try_module_get(idev->owner)) {
470 ret = -ENODEV;
471 goto out;
472 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200473
Hans J. Kochbeafc542006-12-07 10:58:29 +0100474 listener = kmalloc(sizeof(*listener), GFP_KERNEL);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200475 if (!listener) {
476 ret = -ENOMEM;
477 goto err_alloc_listener;
478 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100479
480 listener->dev = idev;
481 listener->event_count = atomic_read(&idev->event);
482 filep->private_data = listener;
483
484 if (idev->info->open) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100485 ret = idev->info->open(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200486 if (ret)
487 goto err_infoopen;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100488 }
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200489 return 0;
490
491err_infoopen:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200492 kfree(listener);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200493
Jonathan Corbet0d4a7bc2008-08-26 17:15:45 -0600494err_alloc_listener:
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200495 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100496
Jonathan Corbetfbc8a812008-05-15 10:39:37 -0600497out:
Hans J. Kochbeafc542006-12-07 10:58:29 +0100498 return ret;
499}
500
501static int uio_fasync(int fd, struct file *filep, int on)
502{
503 struct uio_listener *listener = filep->private_data;
504 struct uio_device *idev = listener->dev;
505
506 return fasync_helper(fd, filep, on, &idev->async_queue);
507}
508
509static int uio_release(struct inode *inode, struct file *filep)
510{
511 int ret = 0;
512 struct uio_listener *listener = filep->private_data;
513 struct uio_device *idev = listener->dev;
514
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200515 if (idev->info->release)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100516 ret = idev->info->release(idev->info, inode);
Uwe Kleine-König610ad502008-04-11 11:07:39 +0200517
518 module_put(idev->owner);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100519 kfree(listener);
520 return ret;
521}
522
523static unsigned int uio_poll(struct file *filep, poll_table *wait)
524{
525 struct uio_listener *listener = filep->private_data;
526 struct uio_device *idev = listener->dev;
527
528 if (idev->info->irq == UIO_IRQ_NONE)
529 return -EIO;
530
531 poll_wait(filep, &idev->wait, wait);
532 if (listener->event_count != atomic_read(&idev->event))
533 return POLLIN | POLLRDNORM;
534 return 0;
535}
536
537static ssize_t uio_read(struct file *filep, char __user *buf,
538 size_t count, loff_t *ppos)
539{
540 struct uio_listener *listener = filep->private_data;
541 struct uio_device *idev = listener->dev;
542 DECLARE_WAITQUEUE(wait, current);
543 ssize_t retval;
544 s32 event_count;
545
546 if (idev->info->irq == UIO_IRQ_NONE)
547 return -EIO;
548
549 if (count != sizeof(s32))
550 return -EINVAL;
551
552 add_wait_queue(&idev->wait, &wait);
553
554 do {
555 set_current_state(TASK_INTERRUPTIBLE);
556
557 event_count = atomic_read(&idev->event);
558 if (event_count != listener->event_count) {
559 if (copy_to_user(buf, &event_count, count))
560 retval = -EFAULT;
561 else {
562 listener->event_count = event_count;
563 retval = count;
564 }
565 break;
566 }
567
568 if (filep->f_flags & O_NONBLOCK) {
569 retval = -EAGAIN;
570 break;
571 }
572
573 if (signal_pending(current)) {
574 retval = -ERESTARTSYS;
575 break;
576 }
577 schedule();
578 } while (1);
579
580 __set_current_state(TASK_RUNNING);
581 remove_wait_queue(&idev->wait, &wait);
582
583 return retval;
584}
585
Hans J. Koch328a14e2008-05-23 13:50:14 +0200586static ssize_t uio_write(struct file *filep, const char __user *buf,
587 size_t count, loff_t *ppos)
588{
589 struct uio_listener *listener = filep->private_data;
590 struct uio_device *idev = listener->dev;
591 ssize_t retval;
592 s32 irq_on;
593
594 if (idev->info->irq == UIO_IRQ_NONE)
595 return -EIO;
596
597 if (count != sizeof(s32))
598 return -EINVAL;
599
600 if (!idev->info->irqcontrol)
601 return -ENOSYS;
602
603 if (copy_from_user(&irq_on, buf, count))
604 return -EFAULT;
605
606 retval = idev->info->irqcontrol(idev->info, irq_on);
607
608 return retval ? retval : sizeof(s32);
609}
610
Hans J. Kochbeafc542006-12-07 10:58:29 +0100611static int uio_find_mem_index(struct vm_area_struct *vma)
612{
613 int mi;
614 struct uio_device *idev = vma->vm_private_data;
615
616 for (mi = 0; mi < MAX_UIO_MAPS; mi++) {
617 if (idev->info->mem[mi].size == 0)
618 return -1;
619 if (vma->vm_pgoff == mi)
620 return mi;
621 }
622 return -1;
623}
624
625static void uio_vma_open(struct vm_area_struct *vma)
626{
627 struct uio_device *idev = vma->vm_private_data;
628 idev->vma_count++;
629}
630
631static void uio_vma_close(struct vm_area_struct *vma)
632{
633 struct uio_device *idev = vma->vm_private_data;
634 idev->vma_count--;
635}
636
Nick Piggina18b6302008-02-06 01:37:35 -0800637static int uio_vma_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
Hans J. Kochbeafc542006-12-07 10:58:29 +0100638{
639 struct uio_device *idev = vma->vm_private_data;
Nick Piggina18b6302008-02-06 01:37:35 -0800640 struct page *page;
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200641 unsigned long offset;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100642
643 int mi = uio_find_mem_index(vma);
644 if (mi < 0)
Nick Piggina18b6302008-02-06 01:37:35 -0800645 return VM_FAULT_SIGBUS;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100646
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200647 /*
648 * We need to subtract mi because userspace uses offset = N*PAGE_SIZE
649 * to use mem[N].
650 */
651 offset = (vmf->pgoff - mi) << PAGE_SHIFT;
652
Hans J. Kochbeafc542006-12-07 10:58:29 +0100653 if (idev->info->mem[mi].memtype == UIO_MEM_LOGICAL)
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200654 page = virt_to_page(idev->info->mem[mi].addr + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100655 else
Andrew G. Harvey02683ff2008-09-24 01:10:02 +0200656 page = vmalloc_to_page((void *)idev->info->mem[mi].addr
657 + offset);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100658 get_page(page);
Nick Piggina18b6302008-02-06 01:37:35 -0800659 vmf->page = page;
660 return 0;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100661}
662
Alexey Dobriyanf0f37e22009-09-27 22:29:37 +0400663static const struct vm_operations_struct uio_vm_ops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100664 .open = uio_vma_open,
665 .close = uio_vma_close,
Nick Piggina18b6302008-02-06 01:37:35 -0800666 .fault = uio_vma_fault,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100667};
668
669static int uio_mmap_physical(struct vm_area_struct *vma)
670{
671 struct uio_device *idev = vma->vm_private_data;
672 int mi = uio_find_mem_index(vma);
673 if (mi < 0)
674 return -EINVAL;
675
676 vma->vm_flags |= VM_IO | VM_RESERVED;
677
Jean-Samuel Chenardc9698d6b2008-03-14 11:28:36 +0100678 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
679
Hans J. Kochbeafc542006-12-07 10:58:29 +0100680 return remap_pfn_range(vma,
681 vma->vm_start,
682 idev->info->mem[mi].addr >> PAGE_SHIFT,
683 vma->vm_end - vma->vm_start,
684 vma->vm_page_prot);
685}
686
687static int uio_mmap_logical(struct vm_area_struct *vma)
688{
689 vma->vm_flags |= VM_RESERVED;
690 vma->vm_ops = &uio_vm_ops;
691 uio_vma_open(vma);
692 return 0;
693}
694
695static int uio_mmap(struct file *filep, struct vm_area_struct *vma)
696{
697 struct uio_listener *listener = filep->private_data;
698 struct uio_device *idev = listener->dev;
699 int mi;
700 unsigned long requested_pages, actual_pages;
701 int ret = 0;
702
703 if (vma->vm_end < vma->vm_start)
704 return -EINVAL;
705
706 vma->vm_private_data = idev;
707
708 mi = uio_find_mem_index(vma);
709 if (mi < 0)
710 return -EINVAL;
711
712 requested_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
Ian Abbott6da2d372009-02-24 17:22:59 +0000713 actual_pages = ((idev->info->mem[mi].addr & ~PAGE_MASK)
714 + idev->info->mem[mi].size + PAGE_SIZE -1) >> PAGE_SHIFT;
Hans J. Kochbeafc542006-12-07 10:58:29 +0100715 if (requested_pages > actual_pages)
716 return -EINVAL;
717
718 if (idev->info->mmap) {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100719 ret = idev->info->mmap(idev->info, vma);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100720 return ret;
721 }
722
723 switch (idev->info->mem[mi].memtype) {
724 case UIO_MEM_PHYS:
725 return uio_mmap_physical(vma);
726 case UIO_MEM_LOGICAL:
727 case UIO_MEM_VIRTUAL:
728 return uio_mmap_logical(vma);
729 default:
730 return -EINVAL;
731 }
732}
733
Jan Engelhardt4f014692008-01-22 20:50:54 +0100734static const struct file_operations uio_fops = {
Hans J. Kochbeafc542006-12-07 10:58:29 +0100735 .owner = THIS_MODULE,
736 .open = uio_open,
737 .release = uio_release,
738 .read = uio_read,
Hans J. Koch328a14e2008-05-23 13:50:14 +0200739 .write = uio_write,
Hans J. Kochbeafc542006-12-07 10:58:29 +0100740 .mmap = uio_mmap,
741 .poll = uio_poll,
742 .fasync = uio_fasync,
743};
744
745static int uio_major_init(void)
746{
747 uio_major = register_chrdev(0, "uio", &uio_fops);
748 if (uio_major < 0)
749 return uio_major;
750 return 0;
751}
752
753static void uio_major_cleanup(void)
754{
755 unregister_chrdev(uio_major, "uio");
756}
757
758static int init_uio_class(void)
759{
760 int ret = 0;
761
762 if (uio_class != NULL) {
763 kref_get(&uio_class->kref);
764 goto exit;
765 }
766
767 /* This is the first time in here, set everything up properly */
768 ret = uio_major_init();
769 if (ret)
770 goto exit;
771
772 uio_class = kzalloc(sizeof(*uio_class), GFP_KERNEL);
773 if (!uio_class) {
774 ret = -ENOMEM;
775 goto err_kzalloc;
776 }
777
778 kref_init(&uio_class->kref);
779 uio_class->class = class_create(THIS_MODULE, "uio");
780 if (IS_ERR(uio_class->class)) {
781 ret = IS_ERR(uio_class->class);
782 printk(KERN_ERR "class_create failed for uio\n");
783 goto err_class_create;
784 }
785 return 0;
786
787err_class_create:
788 kfree(uio_class);
789 uio_class = NULL;
790err_kzalloc:
791 uio_major_cleanup();
792exit:
793 return ret;
794}
795
796static void release_uio_class(struct kref *kref)
797{
798 /* Ok, we cheat as we know we only have one uio_class */
799 class_destroy(uio_class->class);
800 kfree(uio_class);
801 uio_major_cleanup();
802 uio_class = NULL;
803}
804
805static void uio_class_destroy(void)
806{
807 if (uio_class)
808 kref_put(&uio_class->kref, release_uio_class);
809}
810
811/**
812 * uio_register_device - register a new userspace IO device
813 * @owner: module that creates the new device
814 * @parent: parent device
815 * @info: UIO device capabilities
816 *
817 * returns zero on success or a negative error code.
818 */
819int __uio_register_device(struct module *owner,
820 struct device *parent,
821 struct uio_info *info)
822{
823 struct uio_device *idev;
824 int ret = 0;
825
826 if (!parent || !info || !info->name || !info->version)
827 return -EINVAL;
828
829 info->uio_dev = NULL;
830
831 ret = init_uio_class();
832 if (ret)
833 return ret;
834
835 idev = kzalloc(sizeof(*idev), GFP_KERNEL);
836 if (!idev) {
837 ret = -ENOMEM;
838 goto err_kzalloc;
839 }
840
841 idev->owner = owner;
842 idev->info = info;
843 init_waitqueue_head(&idev->wait);
844 atomic_set(&idev->event, 0);
845
846 ret = uio_get_minor(idev);
847 if (ret)
848 goto err_get_minor;
849
Greg Kroah-Hartmana9b12612008-07-21 20:03:34 -0700850 idev->dev = device_create(uio_class->class, parent,
851 MKDEV(uio_major, idev->minor), idev,
852 "uio%d", idev->minor);
Hans J. Kochbeafc542006-12-07 10:58:29 +0100853 if (IS_ERR(idev->dev)) {
854 printk(KERN_ERR "UIO: device register failed\n");
855 ret = PTR_ERR(idev->dev);
856 goto err_device_create;
857 }
Hans J. Kochbeafc542006-12-07 10:58:29 +0100858
859 ret = uio_dev_add_attributes(idev);
860 if (ret)
861 goto err_uio_dev_add_attributes;
862
863 info->uio_dev = idev;
864
865 if (idev->info->irq >= 0) {
866 ret = request_irq(idev->info->irq, uio_interrupt,
867 idev->info->irq_flags, idev->info->name, idev);
868 if (ret)
869 goto err_request_irq;
870 }
871
872 return 0;
873
874err_request_irq:
875 uio_dev_del_attributes(idev);
876err_uio_dev_add_attributes:
877 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
878err_device_create:
879 uio_free_minor(idev);
880err_get_minor:
881 kfree(idev);
882err_kzalloc:
883 uio_class_destroy();
884 return ret;
885}
886EXPORT_SYMBOL_GPL(__uio_register_device);
887
888/**
889 * uio_unregister_device - unregister a industrial IO device
890 * @info: UIO device capabilities
891 *
892 */
893void uio_unregister_device(struct uio_info *info)
894{
895 struct uio_device *idev;
896
897 if (!info || !info->uio_dev)
898 return;
899
900 idev = info->uio_dev;
901
902 uio_free_minor(idev);
903
904 if (info->irq >= 0)
905 free_irq(info->irq, idev);
906
907 uio_dev_del_attributes(idev);
908
909 dev_set_drvdata(idev->dev, NULL);
910 device_destroy(uio_class->class, MKDEV(uio_major, idev->minor));
911 kfree(idev);
912 uio_class_destroy();
913
914 return;
915}
916EXPORT_SYMBOL_GPL(uio_unregister_device);
917
918static int __init uio_init(void)
919{
920 return 0;
921}
922
923static void __exit uio_exit(void)
924{
925}
926
927module_init(uio_init)
928module_exit(uio_exit)
929MODULE_LICENSE("GPL v2");