firmware: use dev_printk when possible
[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
5  *
6  * Please see Documentation/firmware_class/ for more information.
7  *
8  */
9
10 #include <linux/capability.h>
11 #include <linux/device.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/timer.h>
15 #include <linux/vmalloc.h>
16 #include <linux/interrupt.h>
17 #include <linux/bitops.h>
18 #include <linux/mutex.h>
19 #include <linux/kthread.h>
20
21 #include <linux/firmware.h>
22 #include "base.h"
23
24 #define to_dev(obj) container_of(obj, struct device, kobj)
25
26 MODULE_AUTHOR("Manuel Estrada Sainz");
27 MODULE_DESCRIPTION("Multi purpose firmware loading support");
28 MODULE_LICENSE("GPL");
29
30 enum {
31         FW_STATUS_LOADING,
32         FW_STATUS_DONE,
33         FW_STATUS_ABORT,
34 };
35
36 static int loading_timeout = 60;        /* In seconds */
37
38 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
39  * guarding for corner cases a global lock should be OK */
40 static DEFINE_MUTEX(fw_lock);
41
42 struct firmware_priv {
43         char fw_id[FIRMWARE_NAME_MAX];
44         struct completion completion;
45         struct bin_attribute attr_data;
46         struct firmware *fw;
47         unsigned long status;
48         int alloc_size;
49         struct timer_list timeout;
50 };
51
52 #ifdef CONFIG_FW_LOADER
53 extern struct builtin_fw __start_builtin_fw[];
54 extern struct builtin_fw __end_builtin_fw[];
55 #else /* Module case. Avoid ifdefs later; it'll all optimise out */
56 static struct builtin_fw *__start_builtin_fw;
57 static struct builtin_fw *__end_builtin_fw;
58 #endif
59
60 static void
61 fw_load_abort(struct firmware_priv *fw_priv)
62 {
63         set_bit(FW_STATUS_ABORT, &fw_priv->status);
64         wmb();
65         complete(&fw_priv->completion);
66 }
67
68 static ssize_t
69 firmware_timeout_show(struct class *class, char *buf)
70 {
71         return sprintf(buf, "%d\n", loading_timeout);
72 }
73
74 /**
75  * firmware_timeout_store - set number of seconds to wait for firmware
76  * @class: device class pointer
77  * @buf: buffer to scan for timeout value
78  * @count: number of bytes in @buf
79  *
80  *      Sets the number of seconds to wait for the firmware.  Once
81  *      this expires an error will be returned to the driver and no
82  *      firmware will be provided.
83  *
84  *      Note: zero means 'wait forever'.
85  **/
86 static ssize_t
87 firmware_timeout_store(struct class *class, const char *buf, size_t count)
88 {
89         loading_timeout = simple_strtol(buf, NULL, 10);
90         if (loading_timeout < 0)
91                 loading_timeout = 0;
92         return count;
93 }
94
95 static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store);
96
97 static void fw_dev_release(struct device *dev);
98
99 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
100 {
101         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
102
103         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
104                 return -ENOMEM;
105         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
106                 return -ENOMEM;
107
108         return 0;
109 }
110
111 static struct class firmware_class = {
112         .name           = "firmware",
113         .dev_uevent     = firmware_uevent,
114         .dev_release    = fw_dev_release,
115 };
116
117 static ssize_t firmware_loading_show(struct device *dev,
118                                      struct device_attribute *attr, char *buf)
119 {
120         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
121         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
122         return sprintf(buf, "%d\n", loading);
123 }
124
125 /**
126  * firmware_loading_store - set value in the 'loading' control file
127  * @dev: device pointer
128  * @attr: device attribute pointer
129  * @buf: buffer to scan for loading control value
130  * @count: number of bytes in @buf
131  *
132  *      The relevant values are:
133  *
134  *       1: Start a load, discarding any previous partial load.
135  *       0: Conclude the load and hand the data to the driver code.
136  *      -1: Conclude the load with an error and discard any written data.
137  **/
138 static ssize_t firmware_loading_store(struct device *dev,
139                                       struct device_attribute *attr,
140                                       const char *buf, size_t count)
141 {
142         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
143         int loading = simple_strtol(buf, NULL, 10);
144
145         switch (loading) {
146         case 1:
147                 mutex_lock(&fw_lock);
148                 if (!fw_priv->fw) {
149                         mutex_unlock(&fw_lock);
150                         break;
151                 }
152                 vfree(fw_priv->fw->data);
153                 fw_priv->fw->data = NULL;
154                 fw_priv->fw->size = 0;
155                 fw_priv->alloc_size = 0;
156                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
157                 mutex_unlock(&fw_lock);
158                 break;
159         case 0:
160                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
161                         complete(&fw_priv->completion);
162                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
163                         break;
164                 }
165                 /* fallthrough */
166         default:
167                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
168                 /* fallthrough */
169         case -1:
170                 fw_load_abort(fw_priv);
171                 break;
172         }
173
174         return count;
175 }
176
177 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
178
179 static ssize_t
180 firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr,
181                    char *buffer, loff_t offset, size_t count)
182 {
183         struct device *dev = to_dev(kobj);
184         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
185         struct firmware *fw;
186         ssize_t ret_count;
187
188         mutex_lock(&fw_lock);
189         fw = fw_priv->fw;
190         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
191                 ret_count = -ENODEV;
192                 goto out;
193         }
194         ret_count = memory_read_from_buffer(buffer, count, &offset,
195                                                 fw->data, fw->size);
196 out:
197         mutex_unlock(&fw_lock);
198         return ret_count;
199 }
200
201 static int
202 fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
203 {
204         u8 *new_data;
205         int new_size = fw_priv->alloc_size;
206
207         if (min_size <= fw_priv->alloc_size)
208                 return 0;
209
210         new_size = ALIGN(min_size, PAGE_SIZE);
211         new_data = vmalloc(new_size);
212         if (!new_data) {
213                 printk(KERN_ERR "%s: unable to alloc buffer\n", __func__);
214                 /* Make sure that we don't keep incomplete data */
215                 fw_load_abort(fw_priv);
216                 return -ENOMEM;
217         }
218         fw_priv->alloc_size = new_size;
219         if (fw_priv->fw->data) {
220                 memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size);
221                 vfree(fw_priv->fw->data);
222         }
223         fw_priv->fw->data = new_data;
224         BUG_ON(min_size > fw_priv->alloc_size);
225         return 0;
226 }
227
228 /**
229  * firmware_data_write - write method for firmware
230  * @kobj: kobject for the device
231  * @bin_attr: bin_attr structure
232  * @buffer: buffer being written
233  * @offset: buffer offset for write in total data store area
234  * @count: buffer size
235  *
236  *      Data written to the 'data' attribute will be later handed to
237  *      the driver as a firmware image.
238  **/
239 static ssize_t
240 firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr,
241                     char *buffer, loff_t offset, size_t count)
242 {
243         struct device *dev = to_dev(kobj);
244         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
245         struct firmware *fw;
246         ssize_t retval;
247
248         if (!capable(CAP_SYS_RAWIO))
249                 return -EPERM;
250
251         mutex_lock(&fw_lock);
252         fw = fw_priv->fw;
253         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
254                 retval = -ENODEV;
255                 goto out;
256         }
257         retval = fw_realloc_buffer(fw_priv, offset + count);
258         if (retval)
259                 goto out;
260
261         memcpy((u8 *)fw->data + offset, buffer, count);
262
263         fw->size = max_t(size_t, offset + count, fw->size);
264         retval = count;
265 out:
266         mutex_unlock(&fw_lock);
267         return retval;
268 }
269
270 static struct bin_attribute firmware_attr_data_tmpl = {
271         .attr = {.name = "data", .mode = 0644},
272         .size = 0,
273         .read = firmware_data_read,
274         .write = firmware_data_write,
275 };
276
277 static void fw_dev_release(struct device *dev)
278 {
279         struct firmware_priv *fw_priv = dev_get_drvdata(dev);
280
281         kfree(fw_priv);
282         kfree(dev);
283
284         module_put(THIS_MODULE);
285 }
286
287 static void
288 firmware_class_timeout(u_long data)
289 {
290         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
291         fw_load_abort(fw_priv);
292 }
293
294 static inline void fw_setup_device_id(struct device *f_dev, struct device *dev)
295 {
296         /* XXX warning we should watch out for name collisions */
297         strlcpy(f_dev->bus_id, dev->bus_id, BUS_ID_SIZE);
298 }
299
300 static int fw_register_device(struct device **dev_p, const char *fw_name,
301                               struct device *device)
302 {
303         int retval;
304         struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv),
305                                                 GFP_KERNEL);
306         struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL);
307
308         *dev_p = NULL;
309
310         if (!fw_priv || !f_dev) {
311                 dev_err(device, "%s: kmalloc failed\n", __func__);
312                 retval = -ENOMEM;
313                 goto error_kfree;
314         }
315
316         init_completion(&fw_priv->completion);
317         fw_priv->attr_data = firmware_attr_data_tmpl;
318         strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX);
319
320         fw_priv->timeout.function = firmware_class_timeout;
321         fw_priv->timeout.data = (u_long) fw_priv;
322         init_timer(&fw_priv->timeout);
323
324         fw_setup_device_id(f_dev, device);
325         f_dev->parent = device;
326         f_dev->class = &firmware_class;
327         dev_set_drvdata(f_dev, fw_priv);
328         f_dev->uevent_suppress = 1;
329         retval = device_register(f_dev);
330         if (retval) {
331                 dev_err(device, "%s: device_register failed\n", __func__);
332                 goto error_kfree;
333         }
334         *dev_p = f_dev;
335         return 0;
336
337 error_kfree:
338         kfree(fw_priv);
339         kfree(f_dev);
340         return retval;
341 }
342
343 static int fw_setup_device(struct firmware *fw, struct device **dev_p,
344                            const char *fw_name, struct device *device,
345                            int uevent)
346 {
347         struct device *f_dev;
348         struct firmware_priv *fw_priv;
349         int retval;
350
351         *dev_p = NULL;
352         retval = fw_register_device(&f_dev, fw_name, device);
353         if (retval)
354                 goto out;
355
356         /* Need to pin this module until class device is destroyed */
357         __module_get(THIS_MODULE);
358
359         fw_priv = dev_get_drvdata(f_dev);
360
361         fw_priv->fw = fw;
362         retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data);
363         if (retval) {
364                 dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
365                 goto error_unreg;
366         }
367
368         retval = device_create_file(f_dev, &dev_attr_loading);
369         if (retval) {
370                 dev_err(device, "%s: device_create_file failed\n", __func__);
371                 goto error_unreg;
372         }
373
374         if (uevent)
375                 f_dev->uevent_suppress = 0;
376         *dev_p = f_dev;
377         goto out;
378
379 error_unreg:
380         device_unregister(f_dev);
381 out:
382         return retval;
383 }
384
385 static int
386 _request_firmware(const struct firmware **firmware_p, const char *name,
387                  struct device *device, int uevent)
388 {
389         struct device *f_dev;
390         struct firmware_priv *fw_priv;
391         struct firmware *firmware;
392         struct builtin_fw *builtin;
393         int retval;
394
395         if (!firmware_p)
396                 return -EINVAL;
397
398         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
399         if (!firmware) {
400                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
401                         __func__);
402                 retval = -ENOMEM;
403                 goto out;
404         }
405
406         for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
407              builtin++) {
408                 if (strcmp(name, builtin->name))
409                         continue;
410                 dev_info(device, "firmware: using built-in firmware %s\n",
411                          name);
412                 firmware->size = builtin->size;
413                 firmware->data = builtin->data;
414                 return 0;
415         }
416
417         if (uevent)
418                 dev_info(device, "firmware: requesting %s\n", name);
419
420         retval = fw_setup_device(firmware, &f_dev, name, device, uevent);
421         if (retval)
422                 goto error_kfree_fw;
423
424         fw_priv = dev_get_drvdata(f_dev);
425
426         if (uevent) {
427                 if (loading_timeout > 0) {
428                         fw_priv->timeout.expires = jiffies + loading_timeout * HZ;
429                         add_timer(&fw_priv->timeout);
430                 }
431
432                 kobject_uevent(&f_dev->kobj, KOBJ_ADD);
433                 wait_for_completion(&fw_priv->completion);
434                 set_bit(FW_STATUS_DONE, &fw_priv->status);
435                 del_timer_sync(&fw_priv->timeout);
436         } else
437                 wait_for_completion(&fw_priv->completion);
438
439         mutex_lock(&fw_lock);
440         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) {
441                 retval = -ENOENT;
442                 release_firmware(fw_priv->fw);
443                 *firmware_p = NULL;
444         }
445         fw_priv->fw = NULL;
446         mutex_unlock(&fw_lock);
447         device_unregister(f_dev);
448         goto out;
449
450 error_kfree_fw:
451         kfree(firmware);
452         *firmware_p = NULL;
453 out:
454         return retval;
455 }
456
457 /**
458  * request_firmware: - send firmware request and wait for it
459  * @firmware_p: pointer to firmware image
460  * @name: name of firmware file
461  * @device: device for which firmware is being loaded
462  *
463  *      @firmware_p will be used to return a firmware image by the name
464  *      of @name for device @device.
465  *
466  *      Should be called from user context where sleeping is allowed.
467  *
468  *      @name will be used as $FIRMWARE in the uevent environment and
469  *      should be distinctive enough not to be confused with any other
470  *      firmware image for this or any other device.
471  **/
472 int
473 request_firmware(const struct firmware **firmware_p, const char *name,
474                  struct device *device)
475 {
476         int uevent = 1;
477         return _request_firmware(firmware_p, name, device, uevent);
478 }
479
480 /**
481  * release_firmware: - release the resource associated with a firmware image
482  * @fw: firmware resource to release
483  **/
484 void
485 release_firmware(const struct firmware *fw)
486 {
487         struct builtin_fw *builtin;
488
489         if (fw) {
490                 for (builtin = __start_builtin_fw; builtin != __end_builtin_fw;
491                      builtin++) {
492                         if (fw->data == builtin->data)
493                                 goto free_fw;
494                 }
495                 vfree(fw->data);
496         free_fw:
497                 kfree(fw);
498         }
499 }
500
501 /* Async support */
502 struct firmware_work {
503         struct work_struct work;
504         struct module *module;
505         const char *name;
506         struct device *device;
507         void *context;
508         void (*cont)(const struct firmware *fw, void *context);
509         int uevent;
510 };
511
512 static int
513 request_firmware_work_func(void *arg)
514 {
515         struct firmware_work *fw_work = arg;
516         const struct firmware *fw;
517         int ret;
518         if (!arg) {
519                 WARN_ON(1);
520                 return 0;
521         }
522         ret = _request_firmware(&fw, fw_work->name, fw_work->device,
523                 fw_work->uevent);
524         if (ret < 0)
525                 fw_work->cont(NULL, fw_work->context);
526         else {
527                 fw_work->cont(fw, fw_work->context);
528                 release_firmware(fw);
529         }
530         module_put(fw_work->module);
531         kfree(fw_work);
532         return ret;
533 }
534
535 /**
536  * request_firmware_nowait: asynchronous version of request_firmware
537  * @module: module requesting the firmware
538  * @uevent: sends uevent to copy the firmware image if this flag
539  *      is non-zero else the firmware copy must be done manually.
540  * @name: name of firmware file
541  * @device: device for which firmware is being loaded
542  * @context: will be passed over to @cont, and
543  *      @fw may be %NULL if firmware request fails.
544  * @cont: function will be called asynchronously when the firmware
545  *      request is over.
546  *
547  *      Asynchronous variant of request_firmware() for contexts where
548  *      it is not possible to sleep.
549  **/
550 int
551 request_firmware_nowait(
552         struct module *module, int uevent,
553         const char *name, struct device *device, void *context,
554         void (*cont)(const struct firmware *fw, void *context))
555 {
556         struct task_struct *task;
557         struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work),
558                                                 GFP_ATOMIC);
559
560         if (!fw_work)
561                 return -ENOMEM;
562         if (!try_module_get(module)) {
563                 kfree(fw_work);
564                 return -EFAULT;
565         }
566
567         *fw_work = (struct firmware_work) {
568                 .module = module,
569                 .name = name,
570                 .device = device,
571                 .context = context,
572                 .cont = cont,
573                 .uevent = uevent,
574         };
575
576         task = kthread_run(request_firmware_work_func, fw_work,
577                             "firmware/%s", name);
578
579         if (IS_ERR(task)) {
580                 fw_work->cont(NULL, fw_work->context);
581                 module_put(fw_work->module);
582                 kfree(fw_work);
583                 return PTR_ERR(task);
584         }
585         return 0;
586 }
587
588 static int __init
589 firmware_class_init(void)
590 {
591         int error;
592         error = class_register(&firmware_class);
593         if (error) {
594                 printk(KERN_ERR "%s: class_register failed\n", __func__);
595                 return error;
596         }
597         error = class_create_file(&firmware_class, &class_attr_timeout);
598         if (error) {
599                 printk(KERN_ERR "%s: class_create_file failed\n",
600                        __func__);
601                 class_unregister(&firmware_class);
602         }
603         return error;
604
605 }
606 static void __exit
607 firmware_class_exit(void)
608 {
609         class_unregister(&firmware_class);
610 }
611
612 fs_initcall(firmware_class_init);
613 module_exit(firmware_class_exit);
614
615 EXPORT_SYMBOL(release_firmware);
616 EXPORT_SYMBOL(request_firmware);
617 EXPORT_SYMBOL(request_firmware_nowait);