Line data Source code
1 : /* i2c-core.c - a device driver for the iic-bus interface */
2 : /* ------------------------------------------------------------------------- */
3 : /* Copyright (C) 1995-99 Simon G. Vogl
4 :
5 : This program is free software; you can redistribute it and/or modify
6 : it under the terms of the GNU General Public License as published by
7 : the Free Software Foundation; either version 2 of the License, or
8 : (at your option) any later version.
9 :
10 : This program is distributed in the hope that it will be useful,
11 : but WITHOUT ANY WARRANTY; without even the implied warranty of
12 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 : GNU General Public License for more details.
14 :
15 : You should have received a copy of the GNU General Public License
16 : along with this program; if not, write to the Free Software
17 : Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
18 : /* ------------------------------------------------------------------------- */
19 :
20 : /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>.
21 : All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl>
22 : SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and
23 : Jean Delvare <khali@linux-fr.org> */
24 :
25 : #include <linux/module.h>
26 : #include <linux/kernel.h>
27 : #include <linux/errno.h>
28 : #include <linux/slab.h>
29 : #include <linux/i2c.h>
30 : #include <linux/init.h>
31 : #include <linux/idr.h>
32 : #include <linux/mutex.h>
33 : #include <linux/completion.h>
34 : #include <linux/hardirq.h>
35 : #include <linux/irqflags.h>
36 : #include <linux/rwsem.h>
37 : #include <asm/uaccess.h>
38 :
39 : #include "i2c-core.h"
40 :
41 :
42 : /* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees
43 : that device detection, deletion of detected devices, and attach_adapter
44 : and detach_adapter calls are serialized */
45 1 : static DEFINE_MUTEX(core_lock);
46 1 : static DEFINE_IDR(i2c_adapter_idr);
47 1 : static LIST_HEAD(userspace_devices);
48 :
49 1 : static struct device_type i2c_client_type;
50 : static int i2c_check_addr(struct i2c_adapter *adapter, int addr);
51 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver);
52 :
53 : /* ------------------------------------------------------------------------- */
54 :
55 : static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id,
56 : const struct i2c_client *client)
57 : {
58 0 : while (id->name[0]) {
59 0 : if (strcmp(client->name, id->name) == 0)
60 0 : return id;
61 0 : id++;
62 0 : }
63 0 : return NULL;
64 : }
65 :
66 : static int i2c_device_match(struct device *dev, struct device_driver *drv)
67 : {
68 0 : struct i2c_client *client = i2c_verify_client(dev);
69 0 : struct i2c_driver *driver;
70 0 :
71 0 : if (!client)
72 0 : return 0;
73 :
74 0 : driver = to_i2c_driver(drv);
75 : /* match on an id table if there is one */
76 0 : if (driver->id_table)
77 0 : return i2c_match_id(driver->id_table, client) != NULL;
78 :
79 0 : return 0;
80 : }
81 :
82 : #ifdef CONFIG_HOTPLUG
83 :
84 : /* uevent helps with hotplug: modprobe -q $(MODALIAS) */
85 : static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env)
86 : {
87 : struct i2c_client *client = to_i2c_client(dev);
88 :
89 : if (add_uevent_var(env, "MODALIAS=%s%s",
90 : I2C_MODULE_PREFIX, client->name))
91 : return -ENOMEM;
92 : dev_dbg(dev, "uevent\n");
93 : return 0;
94 : }
95 :
96 : #else
97 : #define i2c_device_uevent NULL
98 : #endif /* CONFIG_HOTPLUG */
99 :
100 : static int i2c_device_probe(struct device *dev)
101 : {
102 0 : struct i2c_client *client = i2c_verify_client(dev);
103 0 : struct i2c_driver *driver;
104 0 : int status;
105 0 :
106 0 : if (!client)
107 0 : return 0;
108 0 :
109 0 : driver = to_i2c_driver(dev->driver);
110 0 : if (!driver->probe || !driver->id_table)
111 0 : return -ENODEV;
112 0 : client->driver = driver;
113 0 : if (!device_can_wakeup(&client->dev))
114 0 : device_init_wakeup(&client->dev,
115 : client->flags & I2C_CLIENT_WAKE);
116 : dev_dbg(dev, "probe\n");
117 :
118 0 : status = driver->probe(client, i2c_match_id(driver->id_table, client));
119 0 : if (status)
120 0 : client->driver = NULL;
121 0 : return status;
122 : }
123 :
124 : static int i2c_device_remove(struct device *dev)
125 : {
126 0 : struct i2c_client *client = i2c_verify_client(dev);
127 0 : struct i2c_driver *driver;
128 0 : int status;
129 0 :
130 0 : if (!client || !dev->driver)
131 0 : return 0;
132 :
133 0 : driver = to_i2c_driver(dev->driver);
134 0 : if (driver->remove) {
135 : dev_dbg(dev, "remove\n");
136 0 : status = driver->remove(client);
137 : } else {
138 0 : dev->driver = NULL;
139 0 : status = 0;
140 : }
141 0 : if (status == 0)
142 0 : client->driver = NULL;
143 0 : return status;
144 : }
145 :
146 : static void i2c_device_shutdown(struct device *dev)
147 : {
148 0 : struct i2c_client *client = i2c_verify_client(dev);
149 0 : struct i2c_driver *driver;
150 0 :
151 0 : if (!client || !dev->driver)
152 0 : return;
153 0 : driver = to_i2c_driver(dev->driver);
154 0 : if (driver->shutdown)
155 0 : driver->shutdown(client);
156 0 : }
157 :
158 : #ifdef CONFIG_SUSPEND
159 : static int i2c_device_pm_suspend(struct device *dev)
160 : {
161 : const struct dev_pm_ops *pm;
162 :
163 : if (!dev->driver)
164 : return 0;
165 : pm = dev->driver->pm;
166 : if (!pm || !pm->suspend)
167 : return 0;
168 : return pm->suspend(dev);
169 : }
170 :
171 : static int i2c_device_pm_resume(struct device *dev)
172 : {
173 : const struct dev_pm_ops *pm;
174 :
175 : if (!dev->driver)
176 : return 0;
177 : pm = dev->driver->pm;
178 : if (!pm || !pm->resume)
179 : return 0;
180 : return pm->resume(dev);
181 : }
182 : #else
183 : #define i2c_device_pm_suspend NULL
184 : #define i2c_device_pm_resume NULL
185 : #endif
186 :
187 : static int i2c_device_suspend(struct device *dev, pm_message_t mesg)
188 : {
189 0 : struct i2c_client *client = i2c_verify_client(dev);
190 0 : struct i2c_driver *driver;
191 0 :
192 0 : if (!client || !dev->driver)
193 0 : return 0;
194 0 : driver = to_i2c_driver(dev->driver);
195 0 : if (!driver->suspend)
196 0 : return 0;
197 0 : return driver->suspend(client, mesg);
198 : }
199 :
200 : static int i2c_device_resume(struct device *dev)
201 : {
202 12 : struct i2c_client *client = i2c_verify_client(dev);
203 3 : struct i2c_driver *driver;
204 3 :
205 18 : if (!client || !dev->driver)
206 6 : return 0;
207 9 : driver = to_i2c_driver(dev->driver);
208 9 : if (!driver->resume)
209 3 : return 0;
210 9 : return driver->resume(client);
211 : }
212 :
213 : static void i2c_client_dev_release(struct device *dev)
214 : {
215 3 : kfree(to_i2c_client(dev));
216 : }
217 1 :
218 : static ssize_t
219 : show_name(struct device *dev, struct device_attribute *attr, char *buf)
220 : {
221 2 : return sprintf(buf, "%s\n", dev->type == &i2c_client_type ?
222 9 : to_i2c_client(dev)->name : to_i2c_adapter(dev)->name);
223 1 : }
224 1 :
225 : static ssize_t
226 : show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
227 : {
228 2 : struct i2c_client *client = to_i2c_client(dev);
229 3 : return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name);
230 1 : }
231 1 :
232 1 : static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
233 1 : static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
234 :
235 1 : static struct attribute *i2c_dev_attrs[] = {
236 : &dev_attr_name.attr,
237 : /* modalias helps coldplug: modprobe $(cat .../modalias) */
238 : &dev_attr_modalias.attr,
239 : NULL
240 : };
241 :
242 1 : static struct attribute_group i2c_dev_attr_group = {
243 : .attrs = i2c_dev_attrs,
244 : };
245 :
246 1 : static const struct attribute_group *i2c_dev_attr_groups[] = {
247 : &i2c_dev_attr_group,
248 : NULL
249 : };
250 :
251 1 : static const struct dev_pm_ops i2c_device_pm_ops = {
252 : .suspend = i2c_device_pm_suspend,
253 : .resume = i2c_device_pm_resume,
254 : };
255 :
256 1 : struct bus_type i2c_bus_type = {
257 : .name = "i2c",
258 : .match = i2c_device_match,
259 : .probe = i2c_device_probe,
260 : .remove = i2c_device_remove,
261 : .shutdown = i2c_device_shutdown,
262 : .suspend = i2c_device_suspend,
263 : .resume = i2c_device_resume,
264 : .pm = &i2c_device_pm_ops,
265 : };
266 : EXPORT_SYMBOL_GPL(i2c_bus_type);
267 :
268 1 : static struct device_type i2c_client_type = {
269 : .groups = i2c_dev_attr_groups,
270 : .uevent = i2c_device_uevent,
271 : .release = i2c_client_dev_release,
272 : };
273 :
274 :
275 : /**
276 : * i2c_verify_client - return parameter as i2c_client, or NULL
277 : * @dev: device, probably from some driver model iterator
278 : *
279 : * When traversing the driver model tree, perhaps using driver model
280 : * iterators like @device_for_each_child(), you can't assume very much
281 : * about the nodes you find. Use this function to avoid oopses caused
282 : * by wrongly treating some non-I2C device as an i2c_client.
283 : */
284 : struct i2c_client *i2c_verify_client(struct device *dev)
285 : {
286 6 : return (dev->type == &i2c_client_type)
287 21 : ? to_i2c_client(dev)
288 : : NULL;
289 : }
290 : EXPORT_SYMBOL(i2c_verify_client);
291 :
292 :
293 : /**
294 : * i2c_new_device - instantiate an i2c device
295 : * @adap: the adapter managing the device
296 : * @info: describes one I2C device; bus_num is ignored
297 : * Context: can sleep
298 : *
299 : * Create an i2c device. Binding is handled through driver model
300 : * probe()/remove() methods. A driver may be bound to this device when we
301 : * return from this function, or any later moment (e.g. maybe hotplugging will
302 : * load the driver module). This call is not appropriate for use by mainboard
303 : * initialization logic, which usually runs during an arch_initcall() long
304 : * before any i2c_adapter could exist.
305 : *
306 : * This returns the new i2c client, which may be saved for later use with
307 : * i2c_unregister_device(); or NULL to indicate an error.
308 : */
309 : struct i2c_client *
310 : i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info)
311 : {
312 1 : struct i2c_client *client;
313 1 : int status;
314 1 :
315 4 : client = kzalloc(sizeof *client, GFP_KERNEL);
316 3 : if (!client)
317 2 : return NULL;
318 :
319 1 : client->adapter = adap;
320 :
321 1 : client->dev.platform_data = info->platform_data;
322 :
323 3 : if (info->archdata)
324 1 : client->dev.archdata = *info->archdata;
325 :
326 1 : client->flags = info->flags;
327 1 : client->addr = info->addr;
328 1 : client->irq = info->irq;
329 :
330 1 : strlcpy(client->name, info->type, sizeof(client->name));
331 :
332 : /* Check for address business */
333 3 : status = i2c_check_addr(adap, client->addr);
334 2 : if (status)
335 1 : goto out_err;
336 :
337 1 : client->dev.parent = &client->adapter->dev;
338 1 : client->dev.bus = &i2c_bus_type;
339 1 : client->dev.type = &i2c_client_type;
340 :
341 4 : dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap),
342 : client->addr);
343 1 : status = device_register(&client->dev);
344 2 : if (status)
345 1 : goto out_err;
346 :
347 : dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n",
348 : client->name, dev_name(&client->dev));
349 :
350 1 : return client;
351 2 :
352 : out_err:
353 7 : dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x "
354 : "(%d)\n", client->name, client->addr, status);
355 1 : kfree(client);
356 1 : return NULL;
357 : }
358 : EXPORT_SYMBOL_GPL(i2c_new_device);
359 :
360 :
361 : /**
362 : * i2c_unregister_device - reverse effect of i2c_new_device()
363 : * @client: value returned from i2c_new_device()
364 : * Context: can sleep
365 : */
366 : void i2c_unregister_device(struct i2c_client *client)
367 : {
368 1 : device_unregister(&client->dev);
369 1 : }
370 : EXPORT_SYMBOL_GPL(i2c_unregister_device);
371 :
372 :
373 1 : static const struct i2c_device_id dummy_id[] = {
374 : { "dummy", 0 },
375 : { },
376 : };
377 :
378 : static int dummy_probe(struct i2c_client *client,
379 : const struct i2c_device_id *id)
380 : {
381 1 : return 0;
382 : }
383 :
384 : static int dummy_remove(struct i2c_client *client)
385 : {
386 1 : return 0;
387 : }
388 :
389 1 : static struct i2c_driver dummy_driver = {
390 : .driver.name = "dummy",
391 : .probe = dummy_probe,
392 : .remove = dummy_remove,
393 : .id_table = dummy_id,
394 : };
395 :
396 : /**
397 : * i2c_new_dummy - return a new i2c device bound to a dummy driver
398 : * @adapter: the adapter managing the device
399 : * @address: seven bit address to be used
400 : * Context: can sleep
401 : *
402 : * This returns an I2C client bound to the "dummy" driver, intended for use
403 : * with devices that consume multiple addresses. Examples of such chips
404 : * include various EEPROMS (like 24c04 and 24c08 models).
405 : *
406 : * These dummy devices have two main uses. First, most I2C and SMBus calls
407 : * except i2c_transfer() need a client handle; the dummy will be that handle.
408 : * And second, this prevents the specified address from being bound to a
409 : * different driver.
410 : *
411 : * This returns the new i2c client, which should be saved for later use with
412 : * i2c_unregister_device(); or NULL to indicate an error.
413 : */
414 : struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address)
415 : {
416 0 : struct i2c_board_info info = {
417 0 : I2C_BOARD_INFO("dummy", address),
418 0 : };
419 :
420 0 : return i2c_new_device(adapter, &info);
421 : }
422 : EXPORT_SYMBOL_GPL(i2c_new_dummy);
423 :
424 : /* ------------------------------------------------------------------------- */
425 :
426 : /* I2C bus adapters -- one roots each I2C or SMBUS segment */
427 :
428 : static void i2c_adapter_dev_release(struct device *dev)
429 : {
430 3 : struct i2c_adapter *adap = to_i2c_adapter(dev);
431 2 : complete(&adap->dev_released);
432 1 : }
433 :
434 : /*
435 : * Let users instantiate I2C devices through sysfs. This can be used when
436 : * platform initialization code doesn't contain the proper data for
437 : * whatever reason. Also useful for drivers that do device detection and
438 : * detection fails, either because the device uses an unexpected address,
439 : * or this is a compatible device with different ID register values.
440 : *
441 : * Parameter checking may look overzealous, but we really don't want
442 : * the user to provide incorrect parameters.
443 : */
444 : static ssize_t
445 : i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr,
446 : const char *buf, size_t count)
447 : {
448 3 : struct i2c_adapter *adap = to_i2c_adapter(dev);
449 1 : struct i2c_board_info info;
450 1 : struct i2c_client *client;
451 1 : char *blank, end;
452 1 : int res;
453 1 :
454 5 : dev_warn(dev, "The new_device interface is still experimental "
455 1 : "and may change in a near future\n");
456 2 : memset(&info, 0, sizeof(struct i2c_board_info));
457 1 :
458 2 : blank = strchr(buf, ' ');
459 3 : if (!blank) {
460 5 : dev_err(dev, "%s: Missing parameters\n", "new_device");
461 2 : return -EINVAL;
462 1 : }
463 3 : if (blank - buf > I2C_NAME_SIZE - 1) {
464 5 : dev_err(dev, "%s: Invalid device name\n", "new_device");
465 2 : return -EINVAL;
466 1 : }
467 2 : memcpy(info.type, buf, blank - buf);
468 1 :
469 : /* Parse remaining parameters, reject extra parameters */
470 2 : res = sscanf(++blank, "%hi%c", &info.addr, &end);
471 2 : if (res < 1) {
472 4 : dev_err(dev, "%s: Can't parse I2C address\n", "new_device");
473 1 : return -EINVAL;
474 : }
475 4 : if (res > 1 && end != '\n') {
476 4 : dev_err(dev, "%s: Extra parameters\n", "new_device");
477 1 : return -EINVAL;
478 : }
479 :
480 2 : if (info.addr < 0x03 || info.addr > 0x77) {
481 4 : dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device",
482 : info.addr);
483 1 : return -EINVAL;
484 : }
485 :
486 4 : client = i2c_new_device(adap, &info);
487 2 : if (!client)
488 1 : return -EEXIST;
489 :
490 : /* Keep track of the added device */
491 1 : mutex_lock(&core_lock);
492 2 : list_add_tail(&client->detected, &userspace_devices);
493 1 : mutex_unlock(&core_lock);
494 4 : dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device",
495 : info.type, info.addr);
496 :
497 1 : return count;
498 : }
499 :
500 : /*
501 : * And of course let the users delete the devices they instantiated, if
502 : * they got it wrong. This interface can only be used to delete devices
503 : * instantiated by i2c_sysfs_new_device above. This guarantees that we
504 : * don't delete devices to which some kernel code still has references.
505 : *
506 : * Parameter checking may look overzealous, but we really don't want
507 : * the user to delete the wrong device.
508 : */
509 : static ssize_t
510 : i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr,
511 : const char *buf, size_t count)
512 : {
513 3 : struct i2c_adapter *adap = to_i2c_adapter(dev);
514 1 : struct i2c_client *client, *next;
515 1 : unsigned short addr;
516 1 : char end;
517 1 : int res;
518 1 :
519 1 : /* Parse parameters, reject extra parameters */
520 2 : res = sscanf(buf, "%hi%c", &addr, &end);
521 3 : if (res < 1) {
522 5 : dev_err(dev, "%s: Can't parse I2C address\n", "delete_device");
523 2 : return -EINVAL;
524 1 : }
525 5 : if (res > 1 && end != '\n') {
526 5 : dev_err(dev, "%s: Extra parameters\n", "delete_device");
527 2 : return -EINVAL;
528 1 : }
529 1 :
530 1 : /* Make sure the device was added through sysfs */
531 1 : res = -ENOENT;
532 1 : mutex_lock(&core_lock);
533 10 : list_for_each_entry_safe(client, next, &userspace_devices, detected) {
534 8 : if (client->addr == addr && client->adapter == adap) {
535 6 : dev_info(dev, "%s: Deleting device %s at 0x%02hx\n",
536 : "delete_device", client->name, client->addr);
537 :
538 2 : list_del(&client->detected);
539 3 : i2c_unregister_device(client);
540 1 : res = count;
541 1 : break;
542 : }
543 : }
544 2 : mutex_unlock(&core_lock);
545 :
546 4 : if (res < 0)
547 6 : dev_err(dev, "%s: Can't find device in list\n",
548 : "delete_device");
549 3 : return res;
550 : }
551 :
552 1 : static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device);
553 1 : static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device);
554 :
555 1 : static struct attribute *i2c_adapter_attrs[] = {
556 : &dev_attr_name.attr,
557 : &dev_attr_new_device.attr,
558 : &dev_attr_delete_device.attr,
559 : NULL
560 : };
561 :
562 1 : static struct attribute_group i2c_adapter_attr_group = {
563 : .attrs = i2c_adapter_attrs,
564 : };
565 :
566 1 : static const struct attribute_group *i2c_adapter_attr_groups[] = {
567 : &i2c_adapter_attr_group,
568 : NULL
569 : };
570 :
571 1 : static struct device_type i2c_adapter_type = {
572 : .groups = i2c_adapter_attr_groups,
573 : .release = i2c_adapter_dev_release,
574 : };
575 :
576 : #ifdef CONFIG_I2C_COMPAT
577 : static struct class_compat *i2c_adapter_compat_class;
578 : #endif
579 :
580 : static void i2c_scan_static_board_info(struct i2c_adapter *adapter)
581 : {
582 0 : struct i2c_devinfo *devinfo;
583 0 :
584 0 : down_read(&__i2c_board_lock);
585 0 : list_for_each_entry(devinfo, &__i2c_board_list, list) {
586 0 : if (devinfo->busnum == adapter->nr
587 0 : && !i2c_new_device(adapter,
588 : &devinfo->board_info))
589 0 : dev_err(&adapter->dev,
590 : "Can't create device at 0x%02x\n",
591 : devinfo->board_info.addr);
592 : }
593 0 : up_read(&__i2c_board_lock);
594 0 : }
595 :
596 : static int i2c_do_add_adapter(struct i2c_driver *driver,
597 : struct i2c_adapter *adap)
598 : {
599 : /* Detect supported devices on that bus, and instantiate them */
600 0 : i2c_detect(adap, driver);
601 :
602 : /* Let legacy drivers scan this bus for matching devices */
603 0 : if (driver->attach_adapter) {
604 : /* We ignore the return code; if it fails, too bad */
605 0 : driver->attach_adapter(adap);
606 : }
607 0 : return 0;
608 : }
609 :
610 : static int __process_new_adapter(struct device_driver *d, void *data)
611 : {
612 0 : return i2c_do_add_adapter(to_i2c_driver(d), data);
613 0 : }
614 :
615 : static int i2c_register_adapter(struct i2c_adapter *adap)
616 : {
617 0 : int res = 0, dummy;
618 0 :
619 0 : /* Can't register until after driver model init */
620 0 : if (unlikely(WARN_ON(!i2c_bus_type.p))) {
621 0 : res = -EAGAIN;
622 0 : goto out_list;
623 : }
624 :
625 0 : rt_mutex_init(&adap->bus_lock);
626 :
627 : /* Set default timeout to 1 second if not already set */
628 0 : if (adap->timeout == 0)
629 0 : adap->timeout = HZ;
630 :
631 0 : dev_set_name(&adap->dev, "i2c-%d", adap->nr);
632 0 : adap->dev.bus = &i2c_bus_type;
633 0 : adap->dev.type = &i2c_adapter_type;
634 0 : res = device_register(&adap->dev);
635 0 : if (res)
636 0 : goto out_list;
637 :
638 : dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name);
639 :
640 : #ifdef CONFIG_I2C_COMPAT
641 : res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev,
642 : adap->dev.parent);
643 : if (res)
644 : dev_warn(&adap->dev,
645 : "Failed to create compatibility class link\n");
646 : #endif
647 :
648 : /* create pre-declared device nodes */
649 0 : if (adap->nr < __i2c_first_dynamic_bus_num)
650 0 : i2c_scan_static_board_info(adap);
651 :
652 : /* Notify drivers */
653 0 : mutex_lock(&core_lock);
654 0 : dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap,
655 : __process_new_adapter);
656 0 : mutex_unlock(&core_lock);
657 :
658 0 : return 0;
659 0 :
660 : out_list:
661 0 : mutex_lock(&core_lock);
662 0 : idr_remove(&i2c_adapter_idr, adap->nr);
663 0 : mutex_unlock(&core_lock);
664 0 : return res;
665 : }
666 :
667 : /**
668 : * i2c_add_adapter - declare i2c adapter, use dynamic bus number
669 : * @adapter: the adapter to add
670 : * Context: can sleep
671 : *
672 : * This routine is used to declare an I2C adapter when its bus number
673 : * doesn't matter. Examples: for I2C adapters dynamically added by
674 : * USB links or PCI plugin cards.
675 : *
676 : * When this returns zero, a new bus number was allocated and stored
677 : * in adap->nr, and the specified adapter became available for clients.
678 : * Otherwise, a negative errno value is returned.
679 : */
680 : int i2c_add_adapter(struct i2c_adapter *adapter)
681 : {
682 0 : int id, res = 0;
683 0 :
684 0 : retry:
685 0 : if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
686 0 : return -ENOMEM;
687 :
688 0 : mutex_lock(&core_lock);
689 : /* "above" here means "above or equal to", sigh */
690 0 : res = idr_get_new_above(&i2c_adapter_idr, adapter,
691 : __i2c_first_dynamic_bus_num, &id);
692 0 : mutex_unlock(&core_lock);
693 :
694 0 : if (res < 0) {
695 0 : if (res == -EAGAIN)
696 0 : goto retry;
697 0 : return res;
698 : }
699 :
700 0 : adapter->nr = id;
701 0 : return i2c_register_adapter(adapter);
702 : }
703 : EXPORT_SYMBOL(i2c_add_adapter);
704 :
705 : /**
706 : * i2c_add_numbered_adapter - declare i2c adapter, use static bus number
707 : * @adap: the adapter to register (with adap->nr initialized)
708 : * Context: can sleep
709 : *
710 : * This routine is used to declare an I2C adapter when its bus number
711 : * matters. For example, use it for I2C adapters from system-on-chip CPUs,
712 : * or otherwise built in to the system's mainboard, and where i2c_board_info
713 : * is used to properly configure I2C devices.
714 : *
715 : * If no devices have pre-been declared for this bus, then be sure to
716 : * register the adapter before any dynamically allocated ones. Otherwise
717 : * the required bus ID may not be available.
718 : *
719 : * When this returns zero, the specified adapter became available for
720 : * clients using the bus number provided in adap->nr. Also, the table
721 : * of I2C devices pre-declared using i2c_register_board_info() is scanned,
722 : * and the appropriate driver model device nodes are created. Otherwise, a
723 : * negative errno value is returned.
724 : */
725 : int i2c_add_numbered_adapter(struct i2c_adapter *adap)
726 : {
727 0 : int id;
728 0 : int status;
729 0 :
730 0 : if (adap->nr & ~MAX_ID_MASK)
731 0 : return -EINVAL;
732 :
733 : retry:
734 0 : if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0)
735 0 : return -ENOMEM;
736 :
737 0 : mutex_lock(&core_lock);
738 : /* "above" here means "above or equal to", sigh;
739 : * we need the "equal to" result to force the result
740 : */
741 0 : status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id);
742 0 : if (status == 0 && id != adap->nr) {
743 0 : status = -EBUSY;
744 0 : idr_remove(&i2c_adapter_idr, id);
745 : }
746 0 : mutex_unlock(&core_lock);
747 0 : if (status == -EAGAIN)
748 0 : goto retry;
749 :
750 0 : if (status == 0)
751 0 : status = i2c_register_adapter(adap);
752 0 : return status;
753 : }
754 : EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter);
755 :
756 : static int i2c_do_del_adapter(struct i2c_driver *driver,
757 : struct i2c_adapter *adapter)
758 0 : {
759 0 : struct i2c_client *client, *_n;
760 0 : int res;
761 0 :
762 0 : /* Remove the devices we created ourselves as the result of hardware
763 0 : * probing (using a driver's detect method) */
764 0 : list_for_each_entry_safe(client, _n, &driver->clients, detected) {
765 0 : if (client->adapter == adapter) {
766 0 : dev_dbg(&adapter->dev, "Removing %s at 0x%x\n",
767 : client->name, client->addr);
768 0 : list_del(&client->detected);
769 0 : i2c_unregister_device(client);
770 : }
771 : }
772 :
773 0 : if (!driver->detach_adapter)
774 0 : return 0;
775 0 : res = driver->detach_adapter(adapter);
776 0 : if (res)
777 0 : dev_err(&adapter->dev, "detach_adapter failed (%d) "
778 : "for driver [%s]\n", res, driver->driver.name);
779 0 : return res;
780 : }
781 :
782 : static int __unregister_client(struct device *dev, void *dummy)
783 : {
784 0 : struct i2c_client *client = i2c_verify_client(dev);
785 0 : if (client && strcmp(client->name, "dummy"))
786 0 : i2c_unregister_device(client);
787 0 : return 0;
788 : }
789 :
790 : static int __unregister_dummy(struct device *dev, void *dummy)
791 : {
792 0 : struct i2c_client *client = i2c_verify_client(dev);
793 0 : if (client)
794 0 : i2c_unregister_device(client);
795 0 : return 0;
796 : }
797 :
798 : static int __process_removed_adapter(struct device_driver *d, void *data)
799 : {
800 0 : return i2c_do_del_adapter(to_i2c_driver(d), data);
801 0 : }
802 :
803 : /**
804 : * i2c_del_adapter - unregister I2C adapter
805 : * @adap: the adapter being unregistered
806 : * Context: can sleep
807 : *
808 : * This unregisters an I2C adapter which was previously registered
809 : * by @i2c_add_adapter or @i2c_add_numbered_adapter.
810 : */
811 : int i2c_del_adapter(struct i2c_adapter *adap)
812 : {
813 0 : int res = 0;
814 0 : struct i2c_adapter *found;
815 0 : struct i2c_client *client, *next;
816 0 :
817 0 : /* First make sure that this adapter was ever added */
818 0 : mutex_lock(&core_lock);
819 0 : found = idr_find(&i2c_adapter_idr, adap->nr);
820 0 : mutex_unlock(&core_lock);
821 0 : if (found != adap) {
822 : pr_debug("i2c-core: attempting to delete unregistered "
823 : "adapter [%s]\n", adap->name);
824 0 : return -EINVAL;
825 : }
826 :
827 : /* Tell drivers about this removal */
828 0 : mutex_lock(&core_lock);
829 0 : res = bus_for_each_drv(&i2c_bus_type, NULL, adap,
830 : __process_removed_adapter);
831 0 : mutex_unlock(&core_lock);
832 0 : if (res)
833 0 : return res;
834 :
835 : /* Remove devices instantiated from sysfs */
836 0 : list_for_each_entry_safe(client, next, &userspace_devices, detected) {
837 0 : if (client->adapter == adap) {
838 0 : dev_dbg(&adap->dev, "Removing %s at 0x%x\n",
839 : client->name, client->addr);
840 0 : list_del(&client->detected);
841 0 : i2c_unregister_device(client);
842 : }
843 : }
844 :
845 : /* Detach any active clients. This can't fail, thus we do not
846 : * check the returned value. This is a two-pass process, because
847 : * we can't remove the dummy devices during the first pass: they
848 : * could have been instantiated by real devices wishing to clean
849 : * them up properly, so we give them a chance to do that first. */
850 0 : res = device_for_each_child(&adap->dev, NULL, __unregister_client);
851 0 : res = device_for_each_child(&adap->dev, NULL, __unregister_dummy);
852 :
853 : #ifdef CONFIG_I2C_COMPAT
854 : class_compat_remove_link(i2c_adapter_compat_class, &adap->dev,
855 : adap->dev.parent);
856 : #endif
857 :
858 : /* device name is gone after device_unregister */
859 : dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name);
860 :
861 : /* clean up the sysfs representation */
862 0 : init_completion(&adap->dev_released);
863 0 : device_unregister(&adap->dev);
864 :
865 : /* wait for sysfs to drop all references */
866 0 : wait_for_completion(&adap->dev_released);
867 :
868 : /* free bus id */
869 0 : mutex_lock(&core_lock);
870 0 : idr_remove(&i2c_adapter_idr, adap->nr);
871 0 : mutex_unlock(&core_lock);
872 :
873 : /* Clear the device structure in case this adapter is ever going to be
874 : added again */
875 0 : memset(&adap->dev, 0, sizeof(adap->dev));
876 :
877 0 : return 0;
878 : }
879 : EXPORT_SYMBOL(i2c_del_adapter);
880 :
881 :
882 : /* ------------------------------------------------------------------------- */
883 :
884 : static int __process_new_driver(struct device *dev, void *data)
885 : {
886 0 : if (dev->type != &i2c_adapter_type)
887 0 : return 0;
888 0 : return i2c_do_add_adapter(data, to_i2c_adapter(dev));
889 : }
890 :
891 : /*
892 : * An i2c_driver is used with one or more i2c_client (device) nodes to access
893 : * i2c slave chips, on a bus instance associated with some i2c_adapter.
894 : */
895 :
896 : int i2c_register_driver(struct module *owner, struct i2c_driver *driver)
897 : {
898 1 : int res;
899 1 :
900 1 : /* Can't register until after driver model init */
901 13 : if (unlikely(WARN_ON(!i2c_bus_type.p)))
902 2 : return -EAGAIN;
903 :
904 : /* add the driver to the list of i2c drivers in the driver core */
905 1 : driver->driver.owner = owner;
906 1 : driver->driver.bus = &i2c_bus_type;
907 :
908 : /* When registration returns, the driver core
909 : * will have called probe() for all matching-but-unbound devices.
910 : */
911 1 : res = driver_register(&driver->driver);
912 2 : if (res)
913 1 : return res;
914 :
915 : pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name);
916 :
917 2 : INIT_LIST_HEAD(&driver->clients);
918 : /* Walk the adapters that are already present */
919 1 : mutex_lock(&core_lock);
920 1 : bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_new_driver);
921 1 : mutex_unlock(&core_lock);
922 :
923 1 : return 0;
924 : }
925 : EXPORT_SYMBOL(i2c_register_driver);
926 :
927 : static int __process_removed_driver(struct device *dev, void *data)
928 : {
929 0 : if (dev->type != &i2c_adapter_type)
930 0 : return 0;
931 0 : return i2c_do_del_adapter(data, to_i2c_adapter(dev));
932 : }
933 :
934 : /**
935 : * i2c_del_driver - unregister I2C driver
936 : * @driver: the driver being unregistered
937 : * Context: can sleep
938 : */
939 : void i2c_del_driver(struct i2c_driver *driver)
940 : {
941 2 : mutex_lock(&core_lock);
942 2 : bus_for_each_dev(&i2c_bus_type, NULL, driver, __process_removed_driver);
943 2 : mutex_unlock(&core_lock);
944 :
945 2 : driver_unregister(&driver->driver);
946 : pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name);
947 : }
948 2 : EXPORT_SYMBOL(i2c_del_driver);
949 :
950 : /* ------------------------------------------------------------------------- */
951 :
952 : static int __i2c_check_addr(struct device *dev, void *addrp)
953 : {
954 0 : struct i2c_client *client = i2c_verify_client(dev);
955 0 : int addr = *(int *)addrp;
956 0 :
957 0 : if (client && client->addr == addr)
958 0 : return -EBUSY;
959 0 : return 0;
960 : }
961 :
962 : static int i2c_check_addr(struct i2c_adapter *adapter, int addr)
963 : {
964 3 : return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr);
965 : }
966 :
967 : /**
968 : * i2c_use_client - increments the reference count of the i2c client structure
969 : * @client: the client being referenced
970 : *
971 : * Each live reference to a client should be refcounted. The driver model does
972 : * that automatically as part of driver binding, so that most drivers don't
973 : * need to do this explicitly: they hold a reference until they're unbound
974 : * from the device.
975 : *
976 : * A pointer to the client with the incremented reference counter is returned.
977 : */
978 : struct i2c_client *i2c_use_client(struct i2c_client *client)
979 : {
980 0 : if (client && get_device(&client->dev))
981 0 : return client;
982 0 : return NULL;
983 : }
984 : EXPORT_SYMBOL(i2c_use_client);
985 :
986 : /**
987 : * i2c_release_client - release a use of the i2c client structure
988 : * @client: the client being no longer referenced
989 : *
990 : * Must be called when a user of a client is finished with it.
991 : */
992 : void i2c_release_client(struct i2c_client *client)
993 : {
994 0 : if (client)
995 0 : put_device(&client->dev);
996 0 : }
997 1 : EXPORT_SYMBOL(i2c_release_client);
998 :
999 : struct i2c_cmd_arg {
1000 : unsigned cmd;
1001 : void *arg;
1002 : };
1003 :
1004 : static int i2c_cmd(struct device *dev, void *_arg)
1005 : {
1006 0 : struct i2c_client *client = i2c_verify_client(dev);
1007 0 : struct i2c_cmd_arg *arg = _arg;
1008 0 :
1009 0 : if (client && client->driver && client->driver->command)
1010 0 : client->driver->command(client, arg->cmd, arg->arg);
1011 0 : return 0;
1012 : }
1013 :
1014 : void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg)
1015 : {
1016 0 : struct i2c_cmd_arg cmd_arg;
1017 :
1018 0 : cmd_arg.cmd = cmd;
1019 0 : cmd_arg.arg = arg;
1020 0 : device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd);
1021 0 : }
1022 : EXPORT_SYMBOL(i2c_clients_command);
1023 :
1024 : static int __init i2c_init(void)
1025 : {
1026 1 : int retval;
1027 :
1028 1 : retval = bus_register(&i2c_bus_type);
1029 2 : if (retval)
1030 1 : return retval;
1031 : #ifdef CONFIG_I2C_COMPAT
1032 : i2c_adapter_compat_class = class_compat_register("i2c-adapter");
1033 : if (!i2c_adapter_compat_class) {
1034 : retval = -ENOMEM;
1035 : goto bus_err;
1036 : }
1037 : #endif
1038 2 : retval = i2c_add_driver(&dummy_driver);
1039 2 : if (retval)
1040 1 : goto class_err;
1041 1 : return 0;
1042 1 :
1043 : class_err:
1044 : #ifdef CONFIG_I2C_COMPAT
1045 : class_compat_unregister(i2c_adapter_compat_class);
1046 : bus_err:
1047 : #endif
1048 1 : bus_unregister(&i2c_bus_type);
1049 1 : return retval;
1050 : }
1051 :
1052 : static void __exit i2c_exit(void)
1053 : {
1054 4 : i2c_del_driver(&dummy_driver);
1055 : #ifdef CONFIG_I2C_COMPAT
1056 : class_compat_unregister(i2c_adapter_compat_class);
1057 : #endif
1058 2 : bus_unregister(&i2c_bus_type);
1059 2 : }
1060 :
1061 : /* We must initialize early, because some subsystems register i2c drivers
1062 : * in subsys_initcall() code, but are linked (and initialized) before i2c.
1063 : */
1064 : postcore_initcall(i2c_init);
1065 : module_exit(i2c_exit);
1066 :
1067 : /* ----------------------------------------------------
1068 : * the functional interface to the i2c busses.
1069 : * ----------------------------------------------------
1070 : */
1071 :
1072 : /**
1073 : * i2c_transfer - execute a single or combined I2C message
1074 : * @adap: Handle to I2C bus
1075 : * @msgs: One or more messages to execute before STOP is issued to
1076 : * terminate the operation; each message begins with a START.
1077 : * @num: Number of messages to be executed.
1078 : *
1079 : * Returns negative errno, else the number of messages executed.
1080 : *
1081 : * Note that there is no requirement that each message be sent to
1082 : * the same slave address, although that is the most common model.
1083 : */
1084 : int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
1085 : {
1086 0 : unsigned long orig_jiffies;
1087 0 : int ret, try;
1088 0 :
1089 0 : /* REVISIT the fault reporting model here is weak:
1090 0 : *
1091 0 : * - When we get an error after receiving N bytes from a slave,
1092 : * there is no way to report "N".
1093 : *
1094 : * - When we get a NAK after transmitting N bytes to a slave,
1095 : * there is no way to report "N" ... or to let the master
1096 : * continue executing the rest of this combined message, if
1097 : * that's the appropriate response.
1098 : *
1099 : * - When for example "num" is two and we successfully complete
1100 : * the first message but get an error part way through the
1101 : * second, it's unclear whether that should be reported as
1102 : * one (discarding status on the second message) or errno
1103 : * (discarding status on the first one).
1104 : */
1105 :
1106 0 : if (adap->algo->master_xfer) {
1107 : #ifdef DEBUG
1108 : for (ret = 0; ret < num; ret++) {
1109 : dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, "
1110 : "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD)
1111 : ? 'R' : 'W', msgs[ret].addr, msgs[ret].len,
1112 : (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : "");
1113 : }
1114 : #endif
1115 :
1116 0 : if (in_atomic() || irqs_disabled()) {
1117 0 : ret = rt_mutex_trylock(&adap->bus_lock);
1118 0 : if (!ret)
1119 : /* I2C activity is ongoing. */
1120 0 : return -EAGAIN;
1121 : } else {
1122 0 : rt_mutex_lock(&adap->bus_lock);
1123 : }
1124 :
1125 : /* Retry automatically on arbitration loss */
1126 0 : orig_jiffies = jiffies;
1127 0 : for (ret = 0, try = 0; try <= adap->retries; try++) {
1128 0 : ret = adap->algo->master_xfer(adap, msgs, num);
1129 0 : if (ret != -EAGAIN)
1130 0 : break;
1131 0 : if (time_after(jiffies, orig_jiffies + adap->timeout))
1132 0 : break;
1133 0 : }
1134 0 : rt_mutex_unlock(&adap->bus_lock);
1135 :
1136 0 : return ret;
1137 : } else {
1138 : dev_dbg(&adap->dev, "I2C level transfers not supported\n");
1139 0 : return -EOPNOTSUPP;
1140 : }
1141 : }
1142 : EXPORT_SYMBOL(i2c_transfer);
1143 :
1144 : /**
1145 : * i2c_master_send - issue a single I2C message in master transmit mode
1146 : * @client: Handle to slave device
1147 : * @buf: Data that will be written to the slave
1148 : * @count: How many bytes to write
1149 : *
1150 : * Returns negative errno, or else the number of bytes written.
1151 : */
1152 : int i2c_master_send(struct i2c_client *client,const char *buf ,int count)
1153 : {
1154 0 : int ret;
1155 0 : struct i2c_adapter *adap=client->adapter;
1156 0 : struct i2c_msg msg;
1157 :
1158 0 : msg.addr = client->addr;
1159 0 : msg.flags = client->flags & I2C_M_TEN;
1160 0 : msg.len = count;
1161 0 : msg.buf = (char *)buf;
1162 :
1163 0 : ret = i2c_transfer(adap, &msg, 1);
1164 :
1165 : /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1166 : transmitted, else error code. */
1167 0 : return (ret == 1) ? count : ret;
1168 : }
1169 : EXPORT_SYMBOL(i2c_master_send);
1170 :
1171 : /**
1172 : * i2c_master_recv - issue a single I2C message in master receive mode
1173 : * @client: Handle to slave device
1174 : * @buf: Where to store data read from slave
1175 : * @count: How many bytes to read
1176 : *
1177 : * Returns negative errno, or else the number of bytes read.
1178 : */
1179 : int i2c_master_recv(struct i2c_client *client, char *buf ,int count)
1180 : {
1181 0 : struct i2c_adapter *adap=client->adapter;
1182 0 : struct i2c_msg msg;
1183 0 : int ret;
1184 :
1185 0 : msg.addr = client->addr;
1186 0 : msg.flags = client->flags & I2C_M_TEN;
1187 0 : msg.flags |= I2C_M_RD;
1188 0 : msg.len = count;
1189 0 : msg.buf = buf;
1190 :
1191 0 : ret = i2c_transfer(adap, &msg, 1);
1192 :
1193 : /* If everything went ok (i.e. 1 msg transmitted), return #bytes
1194 : transmitted, else error code. */
1195 0 : return (ret == 1) ? count : ret;
1196 : }
1197 : EXPORT_SYMBOL(i2c_master_recv);
1198 :
1199 : /* ----------------------------------------------------
1200 : * the i2c address scanning function
1201 : * Will not work for 10-bit addresses!
1202 : * ----------------------------------------------------
1203 : */
1204 :
1205 : static int i2c_detect_address(struct i2c_client *temp_client,
1206 : struct i2c_driver *driver)
1207 0 : {
1208 0 : struct i2c_board_info info;
1209 0 : struct i2c_adapter *adapter = temp_client->adapter;
1210 0 : int addr = temp_client->addr;
1211 0 : int err;
1212 0 :
1213 0 : /* Make sure the address is valid */
1214 0 : if (addr < 0x03 || addr > 0x77) {
1215 0 : dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n",
1216 0 : addr);
1217 0 : return -EINVAL;
1218 0 : }
1219 0 :
1220 0 : /* Skip if already in use */
1221 0 : if (i2c_check_addr(adapter, addr))
1222 0 : return 0;
1223 :
1224 : /* Make sure there is something at this address */
1225 0 : if (addr == 0x73 && (adapter->class & I2C_CLASS_HWMON)) {
1226 : /* Special probe for FSC hwmon chips */
1227 : union i2c_smbus_data dummy;
1228 :
1229 0 : if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_READ, 0,
1230 : I2C_SMBUS_BYTE_DATA, &dummy) < 0)
1231 0 : return 0;
1232 : } else {
1233 0 : if (i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
1234 : I2C_SMBUS_QUICK, NULL) < 0)
1235 0 : return 0;
1236 :
1237 : /* Prevent 24RF08 corruption */
1238 0 : if ((addr & ~0x0f) == 0x50)
1239 0 : i2c_smbus_xfer(adapter, addr, 0, I2C_SMBUS_WRITE, 0,
1240 : I2C_SMBUS_QUICK, NULL);
1241 : }
1242 :
1243 : /* Finally call the custom detection function */
1244 0 : memset(&info, 0, sizeof(struct i2c_board_info));
1245 0 : info.addr = addr;
1246 0 : err = driver->detect(temp_client, &info);
1247 0 : if (err) {
1248 : /* -ENODEV is returned if the detection fails. We catch it
1249 : here as this isn't an error. */
1250 0 : return err == -ENODEV ? 0 : err;
1251 : }
1252 :
1253 : /* Consistency check */
1254 0 : if (info.type[0] == '\0') {
1255 0 : dev_err(&adapter->dev, "%s detection function provided "
1256 : "no name for 0x%x\n", driver->driver.name,
1257 : addr);
1258 : } else {
1259 : struct i2c_client *client;
1260 :
1261 : /* Detection succeeded, instantiate the device */
1262 : dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n",
1263 : info.type, info.addr);
1264 0 : client = i2c_new_device(adapter, &info);
1265 0 : if (client)
1266 0 : list_add_tail(&client->detected, &driver->clients);
1267 : else
1268 0 : dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n",
1269 : info.type, info.addr);
1270 : }
1271 0 : return 0;
1272 : }
1273 :
1274 : static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver)
1275 : {
1276 0 : const unsigned short *address_list;
1277 0 : struct i2c_client *temp_client;
1278 0 : int i, err = 0;
1279 0 : int adap_id = i2c_adapter_id(adapter);
1280 0 :
1281 0 : address_list = driver->address_list;
1282 0 : if (!driver->detect || !address_list)
1283 0 : return 0;
1284 0 :
1285 0 : /* Set up a temporary client to help detect callback */
1286 0 : temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
1287 0 : if (!temp_client)
1288 0 : return -ENOMEM;
1289 0 : temp_client->adapter = adapter;
1290 :
1291 : /* Stop here if the classes do not match */
1292 0 : if (!(adapter->class & driver->class))
1293 0 : goto exit_free;
1294 :
1295 : /* Stop here if we can't use SMBUS_QUICK */
1296 0 : if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) {
1297 0 : if (address_list[0] == I2C_CLIENT_END)
1298 0 : goto exit_free;
1299 :
1300 0 : dev_warn(&adapter->dev, "SMBus Quick command not supported, "
1301 : "can't probe for chips\n");
1302 0 : err = -EOPNOTSUPP;
1303 0 : goto exit_free;
1304 : }
1305 :
1306 0 : for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) {
1307 0 : dev_dbg(&adapter->dev, "found normal entry for adapter %d, "
1308 0 : "addr 0x%02x\n", adap_id, address_list[i]);
1309 0 : temp_client->addr = address_list[i];
1310 0 : err = i2c_detect_address(temp_client, driver);
1311 0 : if (err)
1312 0 : goto exit_free;
1313 0 : }
1314 :
1315 : exit_free:
1316 0 : kfree(temp_client);
1317 0 : return err;
1318 : }
1319 :
1320 : struct i2c_client *
1321 : i2c_new_probed_device(struct i2c_adapter *adap,
1322 : struct i2c_board_info *info,
1323 : unsigned short const *addr_list)
1324 0 : {
1325 0 : int i;
1326 0 :
1327 0 : /* Stop here if the bus doesn't support probing */
1328 0 : if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) {
1329 0 : dev_err(&adap->dev, "Probing not supported\n");
1330 0 : return NULL;
1331 0 : }
1332 0 :
1333 0 : for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) {
1334 0 : /* Check address validity */
1335 0 : if (addr_list[i] < 0x03 || addr_list[i] > 0x77) {
1336 0 : dev_warn(&adap->dev, "Invalid 7-bit address "
1337 : "0x%02x\n", addr_list[i]);
1338 0 : continue;
1339 0 : }
1340 :
1341 : /* Check address availability */
1342 0 : if (i2c_check_addr(adap, addr_list[i])) {
1343 : dev_dbg(&adap->dev, "Address 0x%02x already in "
1344 : "use, not probing\n", addr_list[i]);
1345 0 : continue;
1346 : }
1347 :
1348 : /* Test address responsiveness
1349 : The default probe method is a quick write, but it is known
1350 : to corrupt the 24RF08 EEPROMs due to a state machine bug,
1351 : and could also irreversibly write-protect some EEPROMs, so
1352 : for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte
1353 : read instead. Also, some bus drivers don't implement
1354 : quick write, so we fallback to a byte read it that case
1355 : too. */
1356 0 : if ((addr_list[i] & ~0x07) == 0x30
1357 0 : || (addr_list[i] & ~0x0f) == 0x50
1358 : || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) {
1359 : union i2c_smbus_data data;
1360 :
1361 0 : if (i2c_smbus_xfer(adap, addr_list[i], 0,
1362 : I2C_SMBUS_READ, 0,
1363 : I2C_SMBUS_BYTE, &data) >= 0)
1364 0 : break;
1365 : } else {
1366 0 : if (i2c_smbus_xfer(adap, addr_list[i], 0,
1367 : I2C_SMBUS_WRITE, 0,
1368 : I2C_SMBUS_QUICK, NULL) >= 0)
1369 0 : break;
1370 : }
1371 : }
1372 :
1373 0 : if (addr_list[i] == I2C_CLIENT_END) {
1374 : dev_dbg(&adap->dev, "Probing failed, no device found\n");
1375 0 : return NULL;
1376 : }
1377 :
1378 0 : info->addr = addr_list[i];
1379 0 : return i2c_new_device(adap, info);
1380 : }
1381 : EXPORT_SYMBOL_GPL(i2c_new_probed_device);
1382 :
1383 : struct i2c_adapter* i2c_get_adapter(int id)
1384 : {
1385 0 : struct i2c_adapter *adapter;
1386 0 :
1387 0 : mutex_lock(&core_lock);
1388 0 : adapter = idr_find(&i2c_adapter_idr, id);
1389 0 : if (adapter && !try_module_get(adapter->owner))
1390 0 : adapter = NULL;
1391 :
1392 0 : mutex_unlock(&core_lock);
1393 0 : return adapter;
1394 : }
1395 : EXPORT_SYMBOL(i2c_get_adapter);
1396 :
1397 : void i2c_put_adapter(struct i2c_adapter *adap)
1398 : {
1399 0 : module_put(adap->owner);
1400 0 : }
1401 : EXPORT_SYMBOL(i2c_put_adapter);
1402 :
1403 : /* The SMBus parts */
1404 :
1405 : #define POLY (0x1070U << 3)
1406 : static u8 crc8(u16 data)
1407 : {
1408 0 : int i;
1409 :
1410 0 : for(i = 0; i < 8; i++) {
1411 0 : if (data & 0x8000)
1412 0 : data = data ^ POLY;
1413 0 : data = data << 1;
1414 : }
1415 0 : return (u8)(data >> 8);
1416 : }
1417 :
1418 : /* Incremental CRC8 over count bytes in the array pointed to by p */
1419 : static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count)
1420 : {
1421 0 : int i;
1422 :
1423 0 : for(i = 0; i < count; i++)
1424 0 : crc = crc8((crc ^ p[i]) << 8);
1425 0 : return crc;
1426 : }
1427 :
1428 : /* Assume a 7-bit address, which is reasonable for SMBus */
1429 : static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg)
1430 : {
1431 0 : /* The address will be sent first */
1432 0 : u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD);
1433 0 : pec = i2c_smbus_pec(pec, &addr, 1);
1434 :
1435 : /* The data buffer follows */
1436 0 : return i2c_smbus_pec(pec, msg->buf, msg->len);
1437 : }
1438 :
1439 : /* Used for write only transactions */
1440 : static inline void i2c_smbus_add_pec(struct i2c_msg *msg)
1441 : {
1442 0 : msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg);
1443 0 : msg->len++;
1444 0 : }
1445 :
1446 : /* Return <0 on CRC error
1447 : If there was a write before this read (most cases) we need to take the
1448 : partial CRC from the write part into account.
1449 : Note that this function does modify the message (we need to decrease the
1450 : message length to hide the CRC byte from the caller). */
1451 : static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg)
1452 : {
1453 0 : u8 rpec = msg->buf[--msg->len];
1454 0 : cpec = i2c_smbus_msg_pec(cpec, msg);
1455 :
1456 0 : if (rpec != cpec) {
1457 : pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n",
1458 : rpec, cpec);
1459 0 : return -EBADMSG;
1460 : }
1461 0 : return 0;
1462 : }
1463 :
1464 : /**
1465 : * i2c_smbus_read_byte - SMBus "receive byte" protocol
1466 : * @client: Handle to slave device
1467 : *
1468 : * This executes the SMBus "receive byte" protocol, returning negative errno
1469 : * else the byte received from the device.
1470 : */
1471 : s32 i2c_smbus_read_byte(struct i2c_client *client)
1472 : {
1473 0 : union i2c_smbus_data data;
1474 0 : int status;
1475 :
1476 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1477 : I2C_SMBUS_READ, 0,
1478 : I2C_SMBUS_BYTE, &data);
1479 0 : return (status < 0) ? status : data.byte;
1480 : }
1481 : EXPORT_SYMBOL(i2c_smbus_read_byte);
1482 :
1483 : /**
1484 : * i2c_smbus_write_byte - SMBus "send byte" protocol
1485 : * @client: Handle to slave device
1486 : * @value: Byte to be sent
1487 : *
1488 : * This executes the SMBus "send byte" protocol, returning negative errno
1489 : * else zero on success.
1490 : */
1491 : s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value)
1492 : {
1493 0 : return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1494 : I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL);
1495 : }
1496 : EXPORT_SYMBOL(i2c_smbus_write_byte);
1497 :
1498 : /**
1499 : * i2c_smbus_read_byte_data - SMBus "read byte" protocol
1500 : * @client: Handle to slave device
1501 : * @command: Byte interpreted by slave
1502 : *
1503 : * This executes the SMBus "read byte" protocol, returning negative errno
1504 : * else a data byte received from the device.
1505 : */
1506 : s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command)
1507 : {
1508 0 : union i2c_smbus_data data;
1509 0 : int status;
1510 :
1511 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1512 : I2C_SMBUS_READ, command,
1513 : I2C_SMBUS_BYTE_DATA, &data);
1514 0 : return (status < 0) ? status : data.byte;
1515 : }
1516 : EXPORT_SYMBOL(i2c_smbus_read_byte_data);
1517 :
1518 : /**
1519 : * i2c_smbus_write_byte_data - SMBus "write byte" protocol
1520 : * @client: Handle to slave device
1521 : * @command: Byte interpreted by slave
1522 : * @value: Byte being written
1523 : *
1524 : * This executes the SMBus "write byte" protocol, returning negative errno
1525 : * else zero on success.
1526 : */
1527 : s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value)
1528 : {
1529 0 : union i2c_smbus_data data;
1530 0 : data.byte = value;
1531 0 : return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1532 : I2C_SMBUS_WRITE,command,
1533 : I2C_SMBUS_BYTE_DATA,&data);
1534 : }
1535 : EXPORT_SYMBOL(i2c_smbus_write_byte_data);
1536 :
1537 : /**
1538 : * i2c_smbus_read_word_data - SMBus "read word" protocol
1539 : * @client: Handle to slave device
1540 : * @command: Byte interpreted by slave
1541 : *
1542 : * This executes the SMBus "read word" protocol, returning negative errno
1543 : * else a 16-bit unsigned "word" received from the device.
1544 : */
1545 : s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command)
1546 : {
1547 0 : union i2c_smbus_data data;
1548 0 : int status;
1549 :
1550 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1551 : I2C_SMBUS_READ, command,
1552 : I2C_SMBUS_WORD_DATA, &data);
1553 0 : return (status < 0) ? status : data.word;
1554 : }
1555 : EXPORT_SYMBOL(i2c_smbus_read_word_data);
1556 :
1557 : /**
1558 : * i2c_smbus_write_word_data - SMBus "write word" protocol
1559 : * @client: Handle to slave device
1560 : * @command: Byte interpreted by slave
1561 : * @value: 16-bit "word" being written
1562 : *
1563 : * This executes the SMBus "write word" protocol, returning negative errno
1564 : * else zero on success.
1565 : */
1566 : s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value)
1567 : {
1568 0 : union i2c_smbus_data data;
1569 0 : data.word = value;
1570 0 : return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1571 : I2C_SMBUS_WRITE,command,
1572 : I2C_SMBUS_WORD_DATA,&data);
1573 : }
1574 : EXPORT_SYMBOL(i2c_smbus_write_word_data);
1575 :
1576 : /**
1577 : * i2c_smbus_process_call - SMBus "process call" protocol
1578 : * @client: Handle to slave device
1579 : * @command: Byte interpreted by slave
1580 : * @value: 16-bit "word" being written
1581 : *
1582 : * This executes the SMBus "process call" protocol, returning negative errno
1583 : * else a 16-bit unsigned "word" received from the device.
1584 : */
1585 : s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value)
1586 : {
1587 0 : union i2c_smbus_data data;
1588 0 : int status;
1589 0 : data.word = value;
1590 :
1591 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1592 : I2C_SMBUS_WRITE, command,
1593 : I2C_SMBUS_PROC_CALL, &data);
1594 0 : return (status < 0) ? status : data.word;
1595 : }
1596 : EXPORT_SYMBOL(i2c_smbus_process_call);
1597 :
1598 : /**
1599 : * i2c_smbus_read_block_data - SMBus "block read" protocol
1600 : * @client: Handle to slave device
1601 : * @command: Byte interpreted by slave
1602 : * @values: Byte array into which data will be read; big enough to hold
1603 : * the data returned by the slave. SMBus allows at most 32 bytes.
1604 : *
1605 : * This executes the SMBus "block read" protocol, returning negative errno
1606 : * else the number of data bytes in the slave's response.
1607 : *
1608 : * Note that using this function requires that the client's adapter support
1609 : * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers
1610 : * support this; its emulation through I2C messaging relies on a specific
1611 : * mechanism (I2C_M_RECV_LEN) which may not be implemented.
1612 : */
1613 : s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command,
1614 : u8 *values)
1615 0 : {
1616 0 : union i2c_smbus_data data;
1617 : int status;
1618 :
1619 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1620 : I2C_SMBUS_READ, command,
1621 : I2C_SMBUS_BLOCK_DATA, &data);
1622 0 : if (status)
1623 0 : return status;
1624 :
1625 0 : memcpy(values, &data.block[1], data.block[0]);
1626 0 : return data.block[0];
1627 : }
1628 : EXPORT_SYMBOL(i2c_smbus_read_block_data);
1629 :
1630 : /**
1631 : * i2c_smbus_write_block_data - SMBus "block write" protocol
1632 : * @client: Handle to slave device
1633 : * @command: Byte interpreted by slave
1634 : * @length: Size of data block; SMBus allows at most 32 bytes
1635 : * @values: Byte array which will be written.
1636 : *
1637 : * This executes the SMBus "block write" protocol, returning negative errno
1638 : * else zero on success.
1639 : */
1640 : s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command,
1641 : u8 length, const u8 *values)
1642 : {
1643 0 : union i2c_smbus_data data;
1644 0 :
1645 0 : if (length > I2C_SMBUS_BLOCK_MAX)
1646 0 : length = I2C_SMBUS_BLOCK_MAX;
1647 0 : data.block[0] = length;
1648 0 : memcpy(&data.block[1], values, length);
1649 0 : return i2c_smbus_xfer(client->adapter,client->addr,client->flags,
1650 : I2C_SMBUS_WRITE,command,
1651 : I2C_SMBUS_BLOCK_DATA,&data);
1652 : }
1653 : EXPORT_SYMBOL(i2c_smbus_write_block_data);
1654 :
1655 : /* Returns the number of read bytes */
1656 : s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command,
1657 : u8 length, u8 *values)
1658 : {
1659 0 : union i2c_smbus_data data;
1660 0 : int status;
1661 :
1662 0 : if (length > I2C_SMBUS_BLOCK_MAX)
1663 0 : length = I2C_SMBUS_BLOCK_MAX;
1664 0 : data.block[0] = length;
1665 0 : status = i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1666 : I2C_SMBUS_READ, command,
1667 : I2C_SMBUS_I2C_BLOCK_DATA, &data);
1668 0 : if (status < 0)
1669 0 : return status;
1670 :
1671 0 : memcpy(values, &data.block[1], data.block[0]);
1672 0 : return data.block[0];
1673 : }
1674 : EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data);
1675 :
1676 : s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command,
1677 : u8 length, const u8 *values)
1678 : {
1679 0 : union i2c_smbus_data data;
1680 0 :
1681 0 : if (length > I2C_SMBUS_BLOCK_MAX)
1682 0 : length = I2C_SMBUS_BLOCK_MAX;
1683 0 : data.block[0] = length;
1684 0 : memcpy(data.block + 1, values, length);
1685 0 : return i2c_smbus_xfer(client->adapter, client->addr, client->flags,
1686 : I2C_SMBUS_WRITE, command,
1687 : I2C_SMBUS_I2C_BLOCK_DATA, &data);
1688 : }
1689 : EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data);
1690 :
1691 : /* Simulate a SMBus command using the i2c protocol
1692 : No checking of parameters is done! */
1693 : static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr,
1694 : unsigned short flags,
1695 : char read_write, u8 command, int size,
1696 0 : union i2c_smbus_data * data)
1697 0 : {
1698 0 : /* So we need to generate a series of msgs. In the case of writing, we
1699 0 : need to use only one message; when reading, we need two. We initialize
1700 0 : most things with sane defaults, to keep the code below somewhat
1701 0 : simpler. */
1702 0 : unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3];
1703 0 : unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2];
1704 0 : int num = read_write == I2C_SMBUS_READ?2:1;
1705 0 : struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 },
1706 0 : { addr, flags | I2C_M_RD, 0, msgbuf1 }
1707 0 : };
1708 0 : int i;
1709 0 : u8 partial_pec = 0;
1710 0 : int status;
1711 :
1712 0 : msgbuf0[0] = command;
1713 : switch(size) {
1714 0 : case I2C_SMBUS_QUICK:
1715 0 : msg[0].len = 0;
1716 : /* Special case: The read/write field is used as data */
1717 0 : msg[0].flags = flags | (read_write == I2C_SMBUS_READ ?
1718 : I2C_M_RD : 0);
1719 0 : num = 1;
1720 0 : break;
1721 0 : case I2C_SMBUS_BYTE:
1722 0 : if (read_write == I2C_SMBUS_READ) {
1723 : /* Special case: only a read! */
1724 0 : msg[0].flags = I2C_M_RD | flags;
1725 0 : num = 1;
1726 : }
1727 0 : break;
1728 0 : case I2C_SMBUS_BYTE_DATA:
1729 0 : if (read_write == I2C_SMBUS_READ)
1730 0 : msg[1].len = 1;
1731 : else {
1732 0 : msg[0].len = 2;
1733 0 : msgbuf0[1] = data->byte;
1734 : }
1735 0 : break;
1736 0 : case I2C_SMBUS_WORD_DATA:
1737 0 : if (read_write == I2C_SMBUS_READ)
1738 0 : msg[1].len = 2;
1739 : else {
1740 0 : msg[0].len=3;
1741 0 : msgbuf0[1] = data->word & 0xff;
1742 0 : msgbuf0[2] = data->word >> 8;
1743 : }
1744 0 : break;
1745 0 : case I2C_SMBUS_PROC_CALL:
1746 0 : num = 2; /* Special case */
1747 0 : read_write = I2C_SMBUS_READ;
1748 0 : msg[0].len = 3;
1749 0 : msg[1].len = 2;
1750 0 : msgbuf0[1] = data->word & 0xff;
1751 0 : msgbuf0[2] = data->word >> 8;
1752 0 : break;
1753 0 : case I2C_SMBUS_BLOCK_DATA:
1754 0 : if (read_write == I2C_SMBUS_READ) {
1755 0 : msg[1].flags |= I2C_M_RECV_LEN;
1756 0 : msg[1].len = 1; /* block length will be added by
1757 : the underlying bus driver */
1758 : } else {
1759 0 : msg[0].len = data->block[0] + 2;
1760 0 : if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) {
1761 0 : dev_err(&adapter->dev,
1762 : "Invalid block write size %d\n",
1763 : data->block[0]);
1764 0 : return -EINVAL;
1765 : }
1766 0 : for (i = 1; i < msg[0].len; i++)
1767 0 : msgbuf0[i] = data->block[i-1];
1768 0 : }
1769 0 : break;
1770 0 : case I2C_SMBUS_BLOCK_PROC_CALL:
1771 0 : num = 2; /* Another special case */
1772 0 : read_write = I2C_SMBUS_READ;
1773 0 : if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
1774 0 : dev_err(&adapter->dev,
1775 : "Invalid block write size %d\n",
1776 : data->block[0]);
1777 0 : return -EINVAL;
1778 : }
1779 0 : msg[0].len = data->block[0] + 2;
1780 0 : for (i = 1; i < msg[0].len; i++)
1781 0 : msgbuf0[i] = data->block[i-1];
1782 0 : msg[1].flags |= I2C_M_RECV_LEN;
1783 0 : msg[1].len = 1; /* block length will be added by
1784 : the underlying bus driver */
1785 0 : break;
1786 0 : case I2C_SMBUS_I2C_BLOCK_DATA:
1787 0 : if (read_write == I2C_SMBUS_READ) {
1788 0 : msg[1].len = data->block[0];
1789 : } else {
1790 0 : msg[0].len = data->block[0] + 1;
1791 0 : if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
1792 0 : dev_err(&adapter->dev,
1793 : "Invalid block write size %d\n",
1794 : data->block[0]);
1795 0 : return -EINVAL;
1796 : }
1797 0 : for (i = 1; i <= data->block[0]; i++)
1798 0 : msgbuf0[i] = data->block[i];
1799 0 : }
1800 0 : break;
1801 0 : default:
1802 0 : dev_err(&adapter->dev, "Unsupported transaction %d\n", size);
1803 0 : return -EOPNOTSUPP;
1804 : }
1805 :
1806 0 : i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK
1807 : && size != I2C_SMBUS_I2C_BLOCK_DATA);
1808 0 : if (i) {
1809 : /* Compute PEC if first message is a write */
1810 0 : if (!(msg[0].flags & I2C_M_RD)) {
1811 0 : if (num == 1) /* Write only */
1812 0 : i2c_smbus_add_pec(&msg[0]);
1813 : else /* Write followed by read */
1814 0 : partial_pec = i2c_smbus_msg_pec(0, &msg[0]);
1815 : }
1816 : /* Ask for PEC if last message is a read */
1817 0 : if (msg[num-1].flags & I2C_M_RD)
1818 0 : msg[num-1].len++;
1819 : }
1820 :
1821 0 : status = i2c_transfer(adapter, msg, num);
1822 0 : if (status < 0)
1823 0 : return status;
1824 :
1825 : /* Check PEC if last message is a read */
1826 0 : if (i && (msg[num-1].flags & I2C_M_RD)) {
1827 0 : status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
1828 0 : if (status < 0)
1829 0 : return status;
1830 : }
1831 :
1832 0 : if (read_write == I2C_SMBUS_READ)
1833 0 : switch(size) {
1834 0 : case I2C_SMBUS_BYTE:
1835 0 : data->byte = msgbuf0[0];
1836 0 : break;
1837 0 : case I2C_SMBUS_BYTE_DATA:
1838 0 : data->byte = msgbuf1[0];
1839 0 : break;
1840 0 : case I2C_SMBUS_WORD_DATA:
1841 0 : case I2C_SMBUS_PROC_CALL:
1842 0 : data->word = msgbuf1[0] | (msgbuf1[1] << 8);
1843 0 : break;
1844 0 : case I2C_SMBUS_I2C_BLOCK_DATA:
1845 0 : for (i = 0; i < data->block[0]; i++)
1846 0 : data->block[i+1] = msgbuf1[i];
1847 0 : break;
1848 0 : case I2C_SMBUS_BLOCK_DATA:
1849 0 : case I2C_SMBUS_BLOCK_PROC_CALL:
1850 0 : for (i = 0; i < msgbuf1[0] + 1; i++)
1851 0 : data->block[i] = msgbuf1[i];
1852 0 : break;
1853 0 : }
1854 0 : return 0;
1855 0 : }
1856 :
1857 : /**
1858 : * i2c_smbus_xfer - execute SMBus protocol operations
1859 : * @adapter: Handle to I2C bus
1860 : * @addr: Address of SMBus slave on that bus
1861 : * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC)
1862 : * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE
1863 : * @command: Byte interpreted by slave, for protocols which use such bytes
1864 : * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL
1865 : * @data: Data to be read or written
1866 : *
1867 : * This executes an SMBus protocol operation, and returns a negative
1868 : * errno code else zero on success.
1869 : */
1870 : s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags,
1871 : char read_write, u8 command, int protocol,
1872 : union i2c_smbus_data *data)
1873 0 : {
1874 0 : unsigned long orig_jiffies;
1875 0 : int try;
1876 : s32 res;
1877 :
1878 0 : flags &= I2C_M_TEN | I2C_CLIENT_PEC;
1879 :
1880 0 : if (adapter->algo->smbus_xfer) {
1881 0 : rt_mutex_lock(&adapter->bus_lock);
1882 :
1883 : /* Retry automatically on arbitration loss */
1884 0 : orig_jiffies = jiffies;
1885 0 : for (res = 0, try = 0; try <= adapter->retries; try++) {
1886 0 : res = adapter->algo->smbus_xfer(adapter, addr, flags,
1887 0 : read_write, command,
1888 : protocol, data);
1889 0 : if (res != -EAGAIN)
1890 0 : break;
1891 0 : if (time_after(jiffies,
1892 : orig_jiffies + adapter->timeout))
1893 0 : break;
1894 : }
1895 0 : rt_mutex_unlock(&adapter->bus_lock);
1896 : } else
1897 0 : res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write,
1898 : command, protocol, data);
1899 :
1900 0 : return res;
1901 : }
1902 1 : EXPORT_SYMBOL(i2c_smbus_xfer);
1903 :
1904 : MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>");
1905 : MODULE_DESCRIPTION("I2C-Bus main module");
1906 : MODULE_LICENSE("GPL");
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