Linux-2.6.12-rc2
[linux-2.6.git] / drivers / base / firmware_class.c
1 /*
2  * firmware_class.c - Multi purpose firmware loading support
3  *
4  * Copyright (c) 2003 Manuel Estrada Sainz <ranty@debian.org>
5  *
6  * Please see Documentation/firmware_class/ for more information.
7  *
8  */
9
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/timer.h>
14 #include <linux/vmalloc.h>
15 #include <linux/interrupt.h>
16 #include <linux/bitops.h>
17 #include <asm/semaphore.h>
18
19 #include <linux/firmware.h>
20 #include "base.h"
21
22 MODULE_AUTHOR("Manuel Estrada Sainz <ranty@debian.org>");
23 MODULE_DESCRIPTION("Multi purpose firmware loading support");
24 MODULE_LICENSE("GPL");
25
26 enum {
27         FW_STATUS_LOADING,
28         FW_STATUS_DONE,
29         FW_STATUS_ABORT,
30         FW_STATUS_READY,
31 };
32
33 static int loading_timeout = 10;        /* In seconds */
34
35 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
36  * guarding for corner cases a global lock should be OK */
37 static DECLARE_MUTEX(fw_lock);
38
39 struct firmware_priv {
40         char fw_id[FIRMWARE_NAME_MAX];
41         struct completion completion;
42         struct bin_attribute attr_data;
43         struct firmware *fw;
44         unsigned long status;
45         int alloc_size;
46         struct timer_list timeout;
47 };
48
49 static inline void
50 fw_load_abort(struct firmware_priv *fw_priv)
51 {
52         set_bit(FW_STATUS_ABORT, &fw_priv->status);
53         wmb();
54         complete(&fw_priv->completion);
55 }
56
57 static ssize_t
58 firmware_timeout_show(struct class *class, char *buf)
59 {
60         return sprintf(buf, "%d\n", loading_timeout);
61 }
62
63 /**
64  * firmware_timeout_store:
65  * Description:
66  *      Sets the number of seconds to wait for the firmware.  Once
67  *      this expires an error will be return to the driver and no
68  *      firmware will be provided.
69  *
70  *      Note: zero means 'wait for ever'
71  *
72  **/
73 static ssize_t
74 firmware_timeout_store(struct class *class, const char *buf, size_t count)
75 {
76         loading_timeout = simple_strtol(buf, NULL, 10);
77         return count;
78 }
79
80 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
81
82 static void  fw_class_dev_release(struct class_device *class_dev);
83 int firmware_class_hotplug(struct class_device *dev, char **envp,
84                            int num_envp, char *buffer, int buffer_size);
85
86 static struct class firmware_class = {
87         .name           = "firmware",
88         .hotplug        = firmware_class_hotplug,
89         .release        = fw_class_dev_release,
90 };
91
92 int
93 firmware_class_hotplug(struct class_device *class_dev, char **envp,
94                        int num_envp, char *buffer, int buffer_size)
95 {
96         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
97         int i = 0, len = 0;
98
99         if (!test_bit(FW_STATUS_READY, &fw_priv->status))
100                 return -ENODEV;
101
102         if (add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size, &len,
103                         "FIRMWARE=%s", fw_priv->fw_id))
104                 return -ENOMEM;
105
106         envp[i] = NULL;
107
108         return 0;
109 }
110
111 static ssize_t
112 firmware_loading_show(struct class_device *class_dev, char *buf)
113 {
114         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
115         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
116         return sprintf(buf, "%d\n", loading);
117 }
118
119 /**
120  * firmware_loading_store: - loading control file
121  * Description:
122  *      The relevant values are:
123  *
124  *       1: Start a load, discarding any previous partial load.
125  *       0: Conclude the load and handle the data to the driver code.
126  *      -1: Conclude the load with an error and discard any written data.
127  **/
128 static ssize_t
129 firmware_loading_store(struct class_device *class_dev,
130                        const char *buf, size_t count)
131 {
132         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
133         int loading = simple_strtol(buf, NULL, 10);
134
135         switch (loading) {
136         case 1:
137                 down(&fw_lock);
138                 vfree(fw_priv->fw->data);
139                 fw_priv->fw->data = NULL;
140                 fw_priv->fw->size = 0;
141                 fw_priv->alloc_size = 0;
142                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
143                 up(&fw_lock);
144                 break;
145         case 0:
146                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
147                         complete(&fw_priv->completion);
148                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
149                         break;
150                 }
151                 /* fallthrough */
152         default:
153                 printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__,
154                        loading);
155                 /* fallthrough */
156         case -1:
157                 fw_load_abort(fw_priv);
158                 break;
159         }
160
161         return count;
162 }
163
164 static CLASS_DEVICE_ATTR(loading, 0644,
165                         firmware_loading_show, firmware_loading_store);
166
167 static ssize_t
168 firmware_data_read(struct kobject *kobj,
169                    char *buffer, loff_t offset, size_t count)
170 {
171         struct class_device *class_dev = to_class_dev(kobj);
172         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
173         struct firmware *fw;
174         ssize_t ret_count = count;
175
176         down(&fw_lock);
177         fw = fw_priv->fw;
178         if (test_bit(FW_STATUS_DONE, &fw_priv->status)) {
179                 ret_count = -ENODEV;
180                 goto out;
181         }
182         if (offset > fw->size) {
183                 ret_count = 0;
184                 goto out;
185         }
186         if (offset + ret_count > fw->size)
187                 ret_count = fw->size - offset;
188
189         memcpy(buffer, fw->data + offset, ret_count);
190 out:
191         up(&fw_lock);
192         return ret_count;
193 }
194 static int
195 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
196 {
197         u8 *new_data;
198
199         if (min_size <= fw_priv->alloc_size)
200                 return 0;
201
202         new_data = vmalloc(fw_priv->alloc_size + PAGE_SIZE);
203         if (!new_data) {
204                 printk(KERN_ERR "%s: unable to alloc buffer\n", __FUNCTION__);
205                 /* Make sure that we don't keep incomplete data */
206                 fw_load_abort(fw_priv);
207                 return -ENOMEM;
208         }
209         fw_priv->alloc_size += PAGE_SIZE;
210         if (fw_priv->fw->data) {
211                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
212                 vfree(fw_priv->fw->data);
213         }
214         fw_priv->fw->data = new_data;
215         BUG_ON(min_size > fw_priv->alloc_size);
216         return 0;
217 }
218
219 /**
220  * firmware_data_write:
221  *
222  * Description:
223  *
224  *      Data written to the 'data' attribute will be later handled to
225  *      the driver as a firmware image.
226  **/
227 static ssize_t
228 firmware_data_write(struct kobject *kobj,
229                     char *buffer, loff_t offset, size_t count)
230 {
231         struct class_device *class_dev = to_class_dev(kobj);
232         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
233         struct firmware *fw;
234         ssize_t retval;
235
236         if (!capable(CAP_SYS_RAWIO))
237                 return -EPERM;
238         down(&fw_lock);
239         fw = fw_priv->fw;
240         if (test_bit(FW_STATUS_DONE, &fw_priv->status)) {
241                 retval = -ENODEV;
242                 goto out;
243         }
244         retval = fw_realloc_buffer(fw_priv, offset + count);
245         if (retval)
246                 goto out;
247
248         memcpy(fw->data + offset, buffer, count);
249
250         fw->size = max_t(size_t, offset + count, fw->size);
251         retval = count;
252 out:
253         up(&fw_lock);
254         return retval;
255 }
256 static struct bin_attribute firmware_attr_data_tmpl = {
257         .attr = {.name = "data", .mode = 0644, .owner = THIS_MODULE},
258         .size = 0,
259         .read = firmware_data_read,
260         .write = firmware_data_write,
261 };
262
263 static void
264 fw_class_dev_release(struct class_device *class_dev)
265 {
266         struct firmware_priv *fw_priv = class_get_devdata(class_dev);
267
268         kfree(fw_priv);
269         kfree(class_dev);
270
271         module_put(THIS_MODULE);
272 }
273
274 static void
275 firmware_class_timeout(u_long data)
276 {
277         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
278         fw_load_abort(fw_priv);
279 }
280
281 static inline void
282 fw_setup_class_device_id(struct class_device *class_dev, struct device *dev)
283 {
284         /* XXX warning we should watch out for name collisions */
285         strlcpy(class_dev->class_id, dev->bus_id, BUS_ID_SIZE);
286 }
287
288 static int
289 fw_register_class_device(struct class_device **class_dev_p,
290                          const char *fw_name, struct device *device)
291 {
292         int retval;
293         struct firmware_priv *fw_priv = kmalloc(sizeof (struct firmware_priv),
294                                                 GFP_KERNEL);
295         struct class_device *class_dev = kmalloc(sizeof (struct class_device),
296                                                  GFP_KERNEL);
297
298         *class_dev_p = NULL;
299
300         if (!fw_priv || !class_dev) {
301                 printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__);
302                 retval = -ENOMEM;
303                 goto error_kfree;
304         }
305         memset(fw_priv, 0, sizeof (*fw_priv));
306         memset(class_dev, 0, sizeof (*class_dev));
307
308         init_completion(&fw_priv->completion);
309         fw_priv->attr_data = firmware_attr_data_tmpl;
310         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
311
312         fw_priv->timeout.function = firmware_class_timeout;
313         fw_priv->timeout.data = (u_long) fw_priv;
314         init_timer(&fw_priv->timeout);
315
316         fw_setup_class_device_id(class_dev, device);
317         class_dev->dev = device;
318         class_dev->class = &firmware_class;
319         class_set_devdata(class_dev, fw_priv);
320         retval = class_device_register(class_dev);
321         if (retval) {
322                 printk(KERN_ERR "%s: class_device_register failed\n",
323                        __FUNCTION__);
324                 goto error_kfree;
325         }
326         *class_dev_p = class_dev;
327         return 0;
328
329 error_kfree:
330         kfree(fw_priv);
331         kfree(class_dev);
332         return retval;
333 }
334
335 static int
336 fw_setup_class_device(struct firmware *fw, struct class_device **class_dev_p,
337                       const char *fw_name, struct device *device)
338 {
339         struct class_device *class_dev;
340         struct firmware_priv *fw_priv;
341         int retval;
342
343         *class_dev_p = NULL;
344         retval = fw_register_class_device(&class_dev, fw_name, device);
345         if (retval)
346                 goto out;
347
348         /* Need to pin this module until class device is destroyed */
349         __module_get(THIS_MODULE);
350
351         fw_priv = class_get_devdata(class_dev);
352
353         fw_priv->fw = fw;
354         retval = sysfs_create_bin_file(&class_dev->kobj, &fw_priv->attr_data);
355         if (retval) {
356                 printk(KERN_ERR "%s: sysfs_create_bin_file failed\n",
357                        __FUNCTION__);
358                 goto error_unreg;
359         }
360
361         retval = class_device_create_file(class_dev,
362                                           &class_device_attr_loading);
363         if (retval) {
364                 printk(KERN_ERR "%s: class_device_create_file failed\n",
365                        __FUNCTION__);
366                 goto error_unreg;
367         }
368
369         set_bit(FW_STATUS_READY, &fw_priv->status);
370         *class_dev_p = class_dev;
371         goto out;
372
373 error_unreg:
374         class_device_unregister(class_dev);
375 out:
376         return retval;
377 }
378
379 /**
380  * request_firmware: - request firmware to hotplug and wait for it
381  * Description:
382  *      @firmware will be used to return a firmware image by the name
383  *      of @name for device @device.
384  *
385  *      Should be called from user context where sleeping is allowed.
386  *
387  *      @name will be use as $FIRMWARE in the hotplug environment and
388  *      should be distinctive enough not to be confused with any other
389  *      firmware image for this or any other device.
390  **/
391 int
392 request_firmware(const struct firmware **firmware_p, const char *name,
393                  struct device *device)
394 {
395         struct class_device *class_dev;
396         struct firmware_priv *fw_priv;
397         struct firmware *firmware;
398         int retval;
399
400         if (!firmware_p)
401                 return -EINVAL;
402
403         *firmware_p = firmware = kmalloc(sizeof (struct firmware), GFP_KERNEL);
404         if (!firmware) {
405                 printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n",
406                        __FUNCTION__);
407                 retval = -ENOMEM;
408                 goto out;
409         }
410         memset(firmware, 0, sizeof (*firmware));
411
412         retval = fw_setup_class_device(firmware, &class_dev, name, device);
413         if (retval)
414                 goto error_kfree_fw;
415
416         fw_priv = class_get_devdata(class_dev);
417
418         if (loading_timeout) {
419                 fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
420                 add_timer(&fw_priv->timeout);
421         }
422
423         kobject_hotplug(&class_dev->kobj, KOBJ_ADD);
424         wait_for_completion(&fw_priv->completion);
425         set_bit(FW_STATUS_DONE, &fw_priv->status);
426
427         del_timer_sync(&fw_priv->timeout);
428
429         down(&fw_lock);
430         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
431                 retval = -ENOENT;
432                 release_firmware(fw_priv->fw);
433                 *firmware_p = NULL;
434         }
435         fw_priv->fw = NULL;
436         up(&fw_lock);
437         class_device_unregister(class_dev);
438         goto out;
439
440 error_kfree_fw:
441         kfree(firmware);
442         *firmware_p = NULL;
443 out:
444         return retval;
445 }
446
447 /**
448  * release_firmware: - release the resource associated with a firmware image
449  **/
450 void
451 release_firmware(const struct firmware *fw)
452 {
453         if (fw) {
454                 vfree(fw->data);
455                 kfree(fw);
456         }
457 }
458
459 /**
460  * register_firmware: - provide a firmware image for later usage
461  *
462  * Description:
463  *      Make sure that @data will be available by requesting firmware @name.
464  *
465  *      Note: This will not be possible until some kind of persistence
466  *      is available.
467  **/
468 void
469 register_firmware(const char *name, const u8 *data, size_t size)
470 {
471         /* This is meaningless without firmware caching, so until we
472          * decide if firmware caching is reasonable just leave it as a
473          * noop */
474 }
475
476 /* Async support */
477 struct firmware_work {
478         struct work_struct work;
479         struct module *module;
480         const char *name;
481         struct device *device;
482         void *context;
483         void (*cont)(const struct firmware *fw, void *context);
484 };
485
486 static int
487 request_firmware_work_func(void *arg)
488 {
489         struct firmware_work *fw_work = arg;
490         const struct firmware *fw;
491         if (!arg) {
492                 WARN_ON(1);
493                 return 0;
494         }
495         daemonize("%s/%s", "firmware", fw_work->name);
496         request_firmware(&fw, fw_work->name, fw_work->device);
497         fw_work->cont(fw, fw_work->context);
498         release_firmware(fw);
499         module_put(fw_work->module);
500         kfree(fw_work);
501         return 0;
502 }
503
504 /**
505  * request_firmware_nowait:
506  *
507  * Description:
508  *      Asynchronous variant of request_firmware() for contexts where
509  *      it is not possible to sleep.
510  *
511  *      @cont will be called asynchronously when the firmware request is over.
512  *
513  *      @context will be passed over to @cont.
514  *
515  *      @fw may be %NULL if firmware request fails.
516  *
517  **/
518 int
519 request_firmware_nowait(
520         struct module *module,
521         const char *name, struct device *device, void *context,
522         void (*cont)(const struct firmware *fw, void *context))
523 {
524         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
525                                                 GFP_ATOMIC);
526         int ret;
527
528         if (!fw_work)
529                 return -ENOMEM;
530         if (!try_module_get(module)) {
531                 kfree(fw_work);
532                 return -EFAULT;
533         }
534
535         *fw_work = (struct firmware_work) {
536                 .module = module,
537                 .name = name,
538                 .device = device,
539                 .context = context,
540                 .cont = cont,
541         };
542
543         ret = kernel_thread(request_firmware_work_func, fw_work,
544                             CLONE_FS | CLONE_FILES);
545
546         if (ret < 0) {
547                 fw_work->cont(NULL, fw_work->context);
548                 return ret;
549         }
550         return 0;
551 }
552
553 static int __init
554 firmware_class_init(void)
555 {
556         int error;
557         error = class_register(&firmware_class);
558         if (error) {
559                 printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__);
560                 return error;
561         }
562         error = class_create_file(&firmware_class, &class_attr_timeout);
563         if (error) {
564                 printk(KERN_ERR "%s: class_create_file failed\n",
565                        __FUNCTION__);
566                 class_unregister(&firmware_class);
567         }
568         return error;
569
570 }
571 static void __exit
572 firmware_class_exit(void)
573 {
574         class_unregister(&firmware_class);
575 }
576
577 module_init(firmware_class_init);
578 module_exit(firmware_class_exit);
579
580 EXPORT_SYMBOL(release_firmware);
581 EXPORT_SYMBOL(request_firmware);
582 EXPORT_SYMBOL(request_firmware_nowait);
583 EXPORT_SYMBOL(register_firmware);