Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
96de0e25 | 20 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 21 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b JD |
22 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
23 | Jean Delvare <khali@linux-fr.org> */ | |
1da177e4 | 24 | |
1da177e4 LT |
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> | |
d052d1be | 32 | #include <linux/platform_device.h> |
b3585e4f | 33 | #include <linux/mutex.h> |
b8d6f45b | 34 | #include <linux/completion.h> |
cea443a8 MR |
35 | #include <linux/hardirq.h> |
36 | #include <linux/irqflags.h> | |
1da177e4 LT |
37 | #include <asm/uaccess.h> |
38 | ||
9c1600ed DB |
39 | #include "i2c-core.h" |
40 | ||
1da177e4 | 41 | |
caada32a | 42 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
43 | static DEFINE_IDR(i2c_adapter_idr); |
44 | ||
a1d9e6e4 | 45 | #define is_newstyle_driver(d) ((d)->probe || (d)->remove) |
f37dd80a DB |
46 | |
47 | /* ------------------------------------------------------------------------- */ | |
48 | ||
d2653e92 JD |
49 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
50 | const struct i2c_client *client) | |
51 | { | |
52 | while (id->name[0]) { | |
53 | if (strcmp(client->name, id->name) == 0) | |
54 | return id; | |
55 | id++; | |
56 | } | |
57 | return NULL; | |
58 | } | |
59 | ||
1da177e4 LT |
60 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
61 | { | |
7b4fbc50 DB |
62 | struct i2c_client *client = to_i2c_client(dev); |
63 | struct i2c_driver *driver = to_i2c_driver(drv); | |
64 | ||
65 | /* make legacy i2c drivers bypass driver model probing entirely; | |
66 | * such drivers scan each i2c adapter/bus themselves. | |
67 | */ | |
a1d9e6e4 | 68 | if (!is_newstyle_driver(driver)) |
7b4fbc50 DB |
69 | return 0; |
70 | ||
d2653e92 JD |
71 | /* match on an id table if there is one */ |
72 | if (driver->id_table) | |
73 | return i2c_match_id(driver->id_table, client) != NULL; | |
74 | ||
eb8a7908 | 75 | return 0; |
1da177e4 LT |
76 | } |
77 | ||
7b4fbc50 DB |
78 | #ifdef CONFIG_HOTPLUG |
79 | ||
80 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 81 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
82 | { |
83 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 DB |
84 | |
85 | /* by definition, legacy drivers can't hotplug */ | |
d2653e92 | 86 | if (dev->driver) |
7b4fbc50 DB |
87 | return 0; |
88 | ||
eb8a7908 JD |
89 | if (add_uevent_var(env, "MODALIAS=%s%s", |
90 | I2C_MODULE_PREFIX, client->name)) | |
91 | return -ENOMEM; | |
7b4fbc50 DB |
92 | dev_dbg(dev, "uevent\n"); |
93 | return 0; | |
94 | } | |
95 | ||
96 | #else | |
97 | #define i2c_device_uevent NULL | |
98 | #endif /* CONFIG_HOTPLUG */ | |
99 | ||
f37dd80a | 100 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 101 | { |
7b4fbc50 DB |
102 | struct i2c_client *client = to_i2c_client(dev); |
103 | struct i2c_driver *driver = to_i2c_driver(dev->driver); | |
50c3304a | 104 | int status; |
7b4fbc50 | 105 | |
e0457442 | 106 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
107 | return -ENODEV; |
108 | client->driver = driver; | |
109 | dev_dbg(dev, "probe\n"); | |
d2653e92 | 110 | |
e0457442 | 111 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
112 | if (status) |
113 | client->driver = NULL; | |
114 | return status; | |
f37dd80a | 115 | } |
1da177e4 | 116 | |
f37dd80a DB |
117 | static int i2c_device_remove(struct device *dev) |
118 | { | |
a1d9e6e4 DB |
119 | struct i2c_client *client = to_i2c_client(dev); |
120 | struct i2c_driver *driver; | |
121 | int status; | |
122 | ||
123 | if (!dev->driver) | |
124 | return 0; | |
125 | ||
126 | driver = to_i2c_driver(dev->driver); | |
127 | if (driver->remove) { | |
128 | dev_dbg(dev, "remove\n"); | |
129 | status = driver->remove(client); | |
130 | } else { | |
131 | dev->driver = NULL; | |
132 | status = 0; | |
133 | } | |
134 | if (status == 0) | |
135 | client->driver = NULL; | |
136 | return status; | |
1da177e4 LT |
137 | } |
138 | ||
f37dd80a | 139 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 140 | { |
f37dd80a DB |
141 | struct i2c_driver *driver; |
142 | ||
143 | if (!dev->driver) | |
144 | return; | |
145 | driver = to_i2c_driver(dev->driver); | |
146 | if (driver->shutdown) | |
147 | driver->shutdown(to_i2c_client(dev)); | |
1da177e4 LT |
148 | } |
149 | ||
f37dd80a | 150 | static int i2c_device_suspend(struct device * dev, pm_message_t mesg) |
1da177e4 | 151 | { |
f37dd80a DB |
152 | struct i2c_driver *driver; |
153 | ||
154 | if (!dev->driver) | |
155 | return 0; | |
156 | driver = to_i2c_driver(dev->driver); | |
157 | if (!driver->suspend) | |
158 | return 0; | |
159 | return driver->suspend(to_i2c_client(dev), mesg); | |
1da177e4 LT |
160 | } |
161 | ||
f37dd80a | 162 | static int i2c_device_resume(struct device * dev) |
1da177e4 | 163 | { |
f37dd80a DB |
164 | struct i2c_driver *driver; |
165 | ||
166 | if (!dev->driver) | |
167 | return 0; | |
168 | driver = to_i2c_driver(dev->driver); | |
169 | if (!driver->resume) | |
170 | return 0; | |
171 | return driver->resume(to_i2c_client(dev)); | |
1da177e4 LT |
172 | } |
173 | ||
7b4fbc50 DB |
174 | static void i2c_client_release(struct device *dev) |
175 | { | |
176 | struct i2c_client *client = to_i2c_client(dev); | |
177 | complete(&client->released); | |
178 | } | |
179 | ||
9c1600ed DB |
180 | static void i2c_client_dev_release(struct device *dev) |
181 | { | |
182 | kfree(to_i2c_client(dev)); | |
183 | } | |
184 | ||
7b4fbc50 DB |
185 | static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) |
186 | { | |
187 | struct i2c_client *client = to_i2c_client(dev); | |
188 | return sprintf(buf, "%s\n", client->name); | |
189 | } | |
190 | ||
191 | static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
192 | { | |
193 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 194 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
195 | } |
196 | ||
197 | static struct device_attribute i2c_dev_attrs[] = { | |
198 | __ATTR(name, S_IRUGO, show_client_name, NULL), | |
199 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ | |
200 | __ATTR(modalias, S_IRUGO, show_modalias, NULL), | |
201 | { }, | |
202 | }; | |
203 | ||
83eaaed0 | 204 | static struct bus_type i2c_bus_type = { |
f37dd80a | 205 | .name = "i2c", |
7b4fbc50 | 206 | .dev_attrs = i2c_dev_attrs, |
f37dd80a | 207 | .match = i2c_device_match, |
7b4fbc50 | 208 | .uevent = i2c_device_uevent, |
f37dd80a DB |
209 | .probe = i2c_device_probe, |
210 | .remove = i2c_device_remove, | |
211 | .shutdown = i2c_device_shutdown, | |
212 | .suspend = i2c_device_suspend, | |
213 | .resume = i2c_device_resume, | |
b864c7d5 RK |
214 | }; |
215 | ||
9b766b81 DB |
216 | |
217 | /** | |
218 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
219 | * @dev: device, probably from some driver model iterator | |
220 | * | |
221 | * When traversing the driver model tree, perhaps using driver model | |
222 | * iterators like @device_for_each_child(), you can't assume very much | |
223 | * about the nodes you find. Use this function to avoid oopses caused | |
224 | * by wrongly treating some non-I2C device as an i2c_client. | |
225 | */ | |
226 | struct i2c_client *i2c_verify_client(struct device *dev) | |
227 | { | |
228 | return (dev->bus == &i2c_bus_type) | |
229 | ? to_i2c_client(dev) | |
230 | : NULL; | |
231 | } | |
232 | EXPORT_SYMBOL(i2c_verify_client); | |
233 | ||
234 | ||
9c1600ed DB |
235 | /** |
236 | * i2c_new_device - instantiate an i2c device for use with a new style driver | |
237 | * @adap: the adapter managing the device | |
238 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 239 | * Context: can sleep |
9c1600ed DB |
240 | * |
241 | * Create a device to work with a new style i2c driver, where binding is | |
242 | * handled through driver model probe()/remove() methods. This call is not | |
243 | * appropriate for use by mainboad initialization logic, which usually runs | |
244 | * during an arch_initcall() long before any i2c_adapter could exist. | |
245 | * | |
246 | * This returns the new i2c client, which may be saved for later use with | |
247 | * i2c_unregister_device(); or NULL to indicate an error. | |
248 | */ | |
249 | struct i2c_client * | |
250 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
251 | { | |
252 | struct i2c_client *client; | |
253 | int status; | |
254 | ||
255 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
256 | if (!client) | |
257 | return NULL; | |
258 | ||
259 | client->adapter = adap; | |
260 | ||
261 | client->dev.platform_data = info->platform_data; | |
3bbb835d DB |
262 | device_init_wakeup(&client->dev, info->flags & I2C_CLIENT_WAKE); |
263 | ||
264 | client->flags = info->flags & ~I2C_CLIENT_WAKE; | |
9c1600ed DB |
265 | client->addr = info->addr; |
266 | client->irq = info->irq; | |
267 | ||
9c1600ed DB |
268 | strlcpy(client->name, info->type, sizeof(client->name)); |
269 | ||
270 | /* a new style driver may be bound to this device when we | |
271 | * return from this function, or any later moment (e.g. maybe | |
272 | * hotplugging will load the driver module). and the device | |
273 | * refcount model is the standard driver model one. | |
274 | */ | |
275 | status = i2c_attach_client(client); | |
276 | if (status < 0) { | |
277 | kfree(client); | |
278 | client = NULL; | |
279 | } | |
280 | return client; | |
281 | } | |
282 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
283 | ||
284 | ||
285 | /** | |
286 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
287 | * @client: value returned from i2c_new_device() | |
d64f73be | 288 | * Context: can sleep |
9c1600ed DB |
289 | */ |
290 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 DB |
291 | { |
292 | struct i2c_adapter *adapter = client->adapter; | |
293 | struct i2c_driver *driver = client->driver; | |
294 | ||
295 | if (driver && !is_newstyle_driver(driver)) { | |
296 | dev_err(&client->dev, "can't unregister devices " | |
297 | "with legacy drivers\n"); | |
298 | WARN_ON(1); | |
299 | return; | |
300 | } | |
301 | ||
302 | mutex_lock(&adapter->clist_lock); | |
303 | list_del(&client->list); | |
304 | mutex_unlock(&adapter->clist_lock); | |
305 | ||
306 | device_unregister(&client->dev); | |
307 | } | |
9c1600ed | 308 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
309 | |
310 | ||
60b129d7 JD |
311 | static const struct i2c_device_id dummy_id[] = { |
312 | { "dummy", 0 }, | |
313 | { }, | |
314 | }; | |
315 | ||
d2653e92 JD |
316 | static int dummy_probe(struct i2c_client *client, |
317 | const struct i2c_device_id *id) | |
318 | { | |
319 | return 0; | |
320 | } | |
321 | ||
322 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
323 | { |
324 | return 0; | |
325 | } | |
326 | ||
327 | static struct i2c_driver dummy_driver = { | |
328 | .driver.name = "dummy", | |
d2653e92 JD |
329 | .probe = dummy_probe, |
330 | .remove = dummy_remove, | |
60b129d7 | 331 | .id_table = dummy_id, |
e9f1373b DB |
332 | }; |
333 | ||
334 | /** | |
335 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
336 | * @adapter: the adapter managing the device | |
337 | * @address: seven bit address to be used | |
e9f1373b DB |
338 | * Context: can sleep |
339 | * | |
340 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
341 | * with devices that consume multiple addresses. Examples of such chips | |
342 | * include various EEPROMS (like 24c04 and 24c08 models). | |
343 | * | |
344 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
345 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
346 | * And second, this prevents the specified address from being bound to a | |
347 | * different driver. | |
348 | * | |
349 | * This returns the new i2c client, which should be saved for later use with | |
350 | * i2c_unregister_device(); or NULL to indicate an error. | |
351 | */ | |
352 | struct i2c_client * | |
60b129d7 | 353 | i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
354 | { |
355 | struct i2c_board_info info = { | |
60b129d7 | 356 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
357 | }; |
358 | ||
e9f1373b DB |
359 | return i2c_new_device(adapter, &info); |
360 | } | |
361 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
362 | ||
f37dd80a DB |
363 | /* ------------------------------------------------------------------------- */ |
364 | ||
16ffadfc DB |
365 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
366 | ||
83eaaed0 | 367 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 368 | { |
ef2c8321 | 369 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
370 | complete(&adap->dev_released); |
371 | } | |
372 | ||
16ffadfc DB |
373 | static ssize_t |
374 | show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) | |
375 | { | |
ef2c8321 | 376 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
16ffadfc DB |
377 | return sprintf(buf, "%s\n", adap->name); |
378 | } | |
b119dc3f | 379 | |
16ffadfc DB |
380 | static struct device_attribute i2c_adapter_attrs[] = { |
381 | __ATTR(name, S_IRUGO, show_adapter_name, NULL), | |
382 | { }, | |
383 | }; | |
b119dc3f | 384 | |
83eaaed0 | 385 | static struct class i2c_adapter_class = { |
b119dc3f DB |
386 | .owner = THIS_MODULE, |
387 | .name = "i2c-adapter", | |
16ffadfc | 388 | .dev_attrs = i2c_adapter_attrs, |
1da177e4 LT |
389 | }; |
390 | ||
9c1600ed DB |
391 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
392 | { | |
393 | struct i2c_devinfo *devinfo; | |
394 | ||
395 | mutex_lock(&__i2c_board_lock); | |
396 | list_for_each_entry(devinfo, &__i2c_board_list, list) { | |
397 | if (devinfo->busnum == adapter->nr | |
398 | && !i2c_new_device(adapter, | |
399 | &devinfo->board_info)) | |
400 | printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n", | |
401 | i2c_adapter_id(adapter), | |
402 | devinfo->board_info.addr); | |
403 | } | |
404 | mutex_unlock(&__i2c_board_lock); | |
405 | } | |
406 | ||
026526f5 JD |
407 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
408 | { | |
409 | struct i2c_driver *driver = to_i2c_driver(d); | |
410 | struct i2c_adapter *adap = data; | |
411 | ||
412 | if (driver->attach_adapter) { | |
413 | /* We ignore the return code; if it fails, too bad */ | |
414 | driver->attach_adapter(adap); | |
415 | } | |
416 | return 0; | |
417 | } | |
418 | ||
6e13e641 | 419 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 420 | { |
026526f5 | 421 | int res = 0, dummy; |
1da177e4 | 422 | |
5c085d36 IM |
423 | mutex_init(&adap->bus_lock); |
424 | mutex_init(&adap->clist_lock); | |
1da177e4 LT |
425 | INIT_LIST_HEAD(&adap->clients); |
426 | ||
caada32a | 427 | mutex_lock(&core_lock); |
6e13e641 | 428 | |
1da177e4 LT |
429 | /* Add the adapter to the driver core. |
430 | * If the parent pointer is not set up, | |
431 | * we add this adapter to the host bus. | |
432 | */ | |
b119dc3f | 433 | if (adap->dev.parent == NULL) { |
1da177e4 | 434 | adap->dev.parent = &platform_bus; |
fe2c8d51 JD |
435 | pr_debug("I2C adapter driver [%s] forgot to specify " |
436 | "physical device\n", adap->name); | |
b119dc3f | 437 | } |
1da177e4 | 438 | sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); |
1da177e4 | 439 | adap->dev.release = &i2c_adapter_dev_release; |
fccb56e4 | 440 | adap->dev.class = &i2c_adapter_class; |
b119c6c9 JD |
441 | res = device_register(&adap->dev); |
442 | if (res) | |
443 | goto out_list; | |
1da177e4 | 444 | |
b6d7b3d1 JD |
445 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
446 | ||
6e13e641 DB |
447 | /* create pre-declared device nodes for new-style drivers */ |
448 | if (adap->nr < __i2c_first_dynamic_bus_num) | |
449 | i2c_scan_static_board_info(adap); | |
450 | ||
7b4fbc50 | 451 | /* let legacy drivers scan this bus for matching devices */ |
026526f5 JD |
452 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
453 | i2c_do_add_adapter); | |
1da177e4 | 454 | |
1da177e4 | 455 | out_unlock: |
caada32a | 456 | mutex_unlock(&core_lock); |
1da177e4 | 457 | return res; |
b119c6c9 | 458 | |
b119c6c9 | 459 | out_list: |
b119c6c9 JD |
460 | idr_remove(&i2c_adapter_idr, adap->nr); |
461 | goto out_unlock; | |
1da177e4 LT |
462 | } |
463 | ||
6e13e641 DB |
464 | /** |
465 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
466 | * @adapter: the adapter to add | |
d64f73be | 467 | * Context: can sleep |
6e13e641 DB |
468 | * |
469 | * This routine is used to declare an I2C adapter when its bus number | |
470 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
471 | * USB links or PCI plugin cards. | |
472 | * | |
473 | * When this returns zero, a new bus number was allocated and stored | |
474 | * in adap->nr, and the specified adapter became available for clients. | |
475 | * Otherwise, a negative errno value is returned. | |
476 | */ | |
477 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
478 | { | |
479 | int id, res = 0; | |
480 | ||
481 | retry: | |
482 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
483 | return -ENOMEM; | |
484 | ||
caada32a | 485 | mutex_lock(&core_lock); |
6e13e641 DB |
486 | /* "above" here means "above or equal to", sigh */ |
487 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
488 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 489 | mutex_unlock(&core_lock); |
6e13e641 DB |
490 | |
491 | if (res < 0) { | |
492 | if (res == -EAGAIN) | |
493 | goto retry; | |
494 | return res; | |
495 | } | |
496 | ||
497 | adapter->nr = id; | |
498 | return i2c_register_adapter(adapter); | |
499 | } | |
500 | EXPORT_SYMBOL(i2c_add_adapter); | |
501 | ||
502 | /** | |
503 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
504 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 505 | * Context: can sleep |
6e13e641 DB |
506 | * |
507 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
508 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
509 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
510 | * is used to properly configure I2C devices. |
511 | * | |
512 | * If no devices have pre-been declared for this bus, then be sure to | |
513 | * register the adapter before any dynamically allocated ones. Otherwise | |
514 | * the required bus ID may not be available. | |
515 | * | |
516 | * When this returns zero, the specified adapter became available for | |
517 | * clients using the bus number provided in adap->nr. Also, the table | |
518 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
519 | * and the appropriate driver model device nodes are created. Otherwise, a | |
520 | * negative errno value is returned. | |
521 | */ | |
522 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
523 | { | |
524 | int id; | |
525 | int status; | |
526 | ||
527 | if (adap->nr & ~MAX_ID_MASK) | |
528 | return -EINVAL; | |
529 | ||
530 | retry: | |
531 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
532 | return -ENOMEM; | |
533 | ||
caada32a | 534 | mutex_lock(&core_lock); |
6e13e641 DB |
535 | /* "above" here means "above or equal to", sigh; |
536 | * we need the "equal to" result to force the result | |
537 | */ | |
538 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
539 | if (status == 0 && id != adap->nr) { | |
540 | status = -EBUSY; | |
541 | idr_remove(&i2c_adapter_idr, id); | |
542 | } | |
caada32a | 543 | mutex_unlock(&core_lock); |
6e13e641 DB |
544 | if (status == -EAGAIN) |
545 | goto retry; | |
546 | ||
547 | if (status == 0) | |
548 | status = i2c_register_adapter(adap); | |
549 | return status; | |
550 | } | |
551 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
552 | ||
026526f5 JD |
553 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
554 | { | |
555 | struct i2c_driver *driver = to_i2c_driver(d); | |
556 | struct i2c_adapter *adapter = data; | |
557 | int res; | |
558 | ||
559 | if (!driver->detach_adapter) | |
560 | return 0; | |
561 | res = driver->detach_adapter(adapter); | |
562 | if (res) | |
563 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
564 | "for driver [%s]\n", res, driver->driver.name); | |
565 | return res; | |
566 | } | |
567 | ||
d64f73be DB |
568 | /** |
569 | * i2c_del_adapter - unregister I2C adapter | |
570 | * @adap: the adapter being unregistered | |
571 | * Context: can sleep | |
572 | * | |
573 | * This unregisters an I2C adapter which was previously registered | |
574 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
575 | */ | |
1da177e4 LT |
576 | int i2c_del_adapter(struct i2c_adapter *adap) |
577 | { | |
6a03cd93 | 578 | struct i2c_client *client, *_n; |
1da177e4 LT |
579 | int res = 0; |
580 | ||
caada32a | 581 | mutex_lock(&core_lock); |
1da177e4 LT |
582 | |
583 | /* First make sure that this adapter was ever added */ | |
87c6c229 | 584 | if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { |
b6d7b3d1 JD |
585 | pr_debug("i2c-core: attempting to delete unregistered " |
586 | "adapter [%s]\n", adap->name); | |
1da177e4 LT |
587 | res = -EINVAL; |
588 | goto out_unlock; | |
589 | } | |
590 | ||
026526f5 JD |
591 | /* Tell drivers about this removal */ |
592 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, | |
593 | i2c_do_del_adapter); | |
594 | if (res) | |
595 | goto out_unlock; | |
1da177e4 LT |
596 | |
597 | /* detach any active clients. This must be done first, because | |
a551acc2 | 598 | * it can fail; in which case we give up. */ |
6a03cd93 | 599 | list_for_each_entry_safe(client, _n, &adap->clients, list) { |
a1d9e6e4 DB |
600 | struct i2c_driver *driver; |
601 | ||
a1d9e6e4 DB |
602 | driver = client->driver; |
603 | ||
604 | /* new style, follow standard driver model */ | |
605 | if (!driver || is_newstyle_driver(driver)) { | |
606 | i2c_unregister_device(client); | |
607 | continue; | |
608 | } | |
1da177e4 | 609 | |
a1d9e6e4 DB |
610 | /* legacy drivers create and remove clients themselves */ |
611 | if ((res = driver->detach_client(client))) { | |
b6d7b3d1 JD |
612 | dev_err(&adap->dev, "detach_client failed for client " |
613 | "[%s] at address 0x%02x\n", client->name, | |
1da177e4 LT |
614 | client->addr); |
615 | goto out_unlock; | |
616 | } | |
617 | } | |
618 | ||
619 | /* clean up the sysfs representation */ | |
620 | init_completion(&adap->dev_released); | |
1da177e4 | 621 | device_unregister(&adap->dev); |
1da177e4 LT |
622 | |
623 | /* wait for sysfs to drop all references */ | |
624 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 625 | |
6e13e641 | 626 | /* free bus id */ |
1da177e4 LT |
627 | idr_remove(&i2c_adapter_idr, adap->nr); |
628 | ||
b6d7b3d1 | 629 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
630 | |
631 | out_unlock: | |
caada32a | 632 | mutex_unlock(&core_lock); |
1da177e4 LT |
633 | return res; |
634 | } | |
c0564606 | 635 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
636 | |
637 | ||
7b4fbc50 DB |
638 | /* ------------------------------------------------------------------------- */ |
639 | ||
7f101a97 DY |
640 | static int __attach_adapter(struct device *dev, void *data) |
641 | { | |
642 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
643 | struct i2c_driver *driver = data; | |
644 | ||
645 | driver->attach_adapter(adapter); | |
646 | ||
647 | return 0; | |
648 | } | |
649 | ||
7b4fbc50 DB |
650 | /* |
651 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
652 | * i2c slave chips, on a bus instance associated with some i2c_adapter. There | |
653 | * are two models for binding the driver to its device: "new style" drivers | |
654 | * follow the standard Linux driver model and just respond to probe() calls | |
655 | * issued if the driver core sees they match(); "legacy" drivers create device | |
656 | * nodes themselves. | |
1da177e4 LT |
657 | */ |
658 | ||
de59cf9e | 659 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 660 | { |
7eebcb7c | 661 | int res; |
1da177e4 | 662 | |
7b4fbc50 | 663 | /* new style driver methods can't mix with legacy ones */ |
a1d9e6e4 | 664 | if (is_newstyle_driver(driver)) { |
7b4fbc50 DB |
665 | if (driver->attach_adapter || driver->detach_adapter |
666 | || driver->detach_client) { | |
667 | printk(KERN_WARNING | |
668 | "i2c-core: driver [%s] is confused\n", | |
669 | driver->driver.name); | |
670 | return -EINVAL; | |
671 | } | |
672 | } | |
673 | ||
1da177e4 | 674 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 675 | driver->driver.owner = owner; |
1da177e4 | 676 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 677 | |
6e13e641 DB |
678 | /* for new style drivers, when registration returns the driver core |
679 | * will have called probe() for all matching-but-unbound devices. | |
680 | */ | |
1da177e4 LT |
681 | res = driver_register(&driver->driver); |
682 | if (res) | |
7eebcb7c | 683 | return res; |
438d6c2c | 684 | |
caada32a | 685 | mutex_lock(&core_lock); |
7eebcb7c | 686 | |
35d8b2e6 | 687 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 688 | |
7b4fbc50 | 689 | /* legacy drivers scan i2c busses directly */ |
7f101a97 DY |
690 | if (driver->attach_adapter) |
691 | class_for_each_device(&i2c_adapter_class, driver, | |
692 | __attach_adapter); | |
4ad4eac6 | 693 | |
7f101a97 DY |
694 | mutex_unlock(&core_lock); |
695 | return 0; | |
696 | } | |
697 | EXPORT_SYMBOL(i2c_register_driver); | |
698 | ||
699 | static int __detach_adapter(struct device *dev, void *data) | |
700 | { | |
701 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
702 | struct i2c_driver *driver = data; | |
703 | ||
704 | /* Have a look at each adapter, if clients of this driver are still | |
705 | * attached. If so, detach them to be able to kill the driver | |
706 | * afterwards. | |
707 | */ | |
708 | if (driver->detach_adapter) { | |
709 | if (driver->detach_adapter(adapter)) | |
710 | dev_err(&adapter->dev, | |
711 | "detach_adapter failed for driver [%s]\n", | |
712 | driver->driver.name); | |
713 | } else { | |
6a03cd93 | 714 | struct i2c_client *client, *_n; |
7f101a97 | 715 | |
6a03cd93 | 716 | list_for_each_entry_safe(client, _n, &adapter->clients, list) { |
7f101a97 DY |
717 | if (client->driver != driver) |
718 | continue; | |
719 | dev_dbg(&adapter->dev, | |
720 | "detaching client [%s] at 0x%02x\n", | |
721 | client->name, client->addr); | |
722 | if (driver->detach_client(client)) | |
723 | dev_err(&adapter->dev, "detach_client " | |
724 | "failed for client [%s] at 0x%02x\n", | |
725 | client->name, client->addr); | |
1da177e4 LT |
726 | } |
727 | } | |
728 | ||
7eebcb7c | 729 | return 0; |
1da177e4 LT |
730 | } |
731 | ||
a1d9e6e4 DB |
732 | /** |
733 | * i2c_del_driver - unregister I2C driver | |
734 | * @driver: the driver being unregistered | |
d64f73be | 735 | * Context: can sleep |
a1d9e6e4 | 736 | */ |
b3e82096 | 737 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 738 | { |
caada32a | 739 | mutex_lock(&core_lock); |
1da177e4 | 740 | |
f7050bd7 JD |
741 | /* legacy driver? */ |
742 | if (!is_newstyle_driver(driver)) | |
743 | class_for_each_device(&i2c_adapter_class, driver, | |
744 | __detach_adapter); | |
1da177e4 LT |
745 | |
746 | driver_unregister(&driver->driver); | |
35d8b2e6 | 747 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 748 | |
caada32a | 749 | mutex_unlock(&core_lock); |
1da177e4 | 750 | } |
c0564606 | 751 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 752 | |
7b4fbc50 DB |
753 | /* ------------------------------------------------------------------------- */ |
754 | ||
9b766b81 | 755 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 756 | { |
9b766b81 DB |
757 | struct i2c_client *client = i2c_verify_client(dev); |
758 | int addr = *(int *)addrp; | |
1da177e4 | 759 | |
9b766b81 DB |
760 | if (client && client->addr == addr) |
761 | return -EBUSY; | |
1da177e4 LT |
762 | return 0; |
763 | } | |
764 | ||
5e31c2bd | 765 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 766 | { |
9b766b81 | 767 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
768 | } |
769 | ||
770 | int i2c_attach_client(struct i2c_client *client) | |
771 | { | |
772 | struct i2c_adapter *adapter = client->adapter; | |
b119c6c9 | 773 | int res = 0; |
1da177e4 | 774 | |
1da177e4 | 775 | client->dev.parent = &client->adapter->dev; |
1da177e4 | 776 | client->dev.bus = &i2c_bus_type; |
9c1600ed DB |
777 | |
778 | if (client->driver) | |
779 | client->dev.driver = &client->driver->driver; | |
780 | ||
de81d2aa | 781 | if (client->driver && !is_newstyle_driver(client->driver)) { |
9c1600ed | 782 | client->dev.release = i2c_client_release; |
de81d2aa DB |
783 | client->dev.uevent_suppress = 1; |
784 | } else | |
9c1600ed | 785 | client->dev.release = i2c_client_dev_release; |
438d6c2c | 786 | |
1da177e4 LT |
787 | snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), |
788 | "%d-%04x", i2c_adapter_id(adapter), client->addr); | |
b119c6c9 JD |
789 | res = device_register(&client->dev); |
790 | if (res) | |
86ec5ec8 DB |
791 | goto out_err; |
792 | ||
793 | mutex_lock(&adapter->clist_lock); | |
794 | list_add_tail(&client->list, &adapter->clients); | |
b119c6c9 | 795 | mutex_unlock(&adapter->clist_lock); |
77ed74da | 796 | |
86ec5ec8 DB |
797 | dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", |
798 | client->name, client->dev.bus_id); | |
799 | ||
77ed74da JD |
800 | if (adapter->client_register) { |
801 | if (adapter->client_register(client)) { | |
802 | dev_dbg(&adapter->dev, "client_register " | |
803 | "failed for client [%s] at 0x%02x\n", | |
804 | client->name, client->addr); | |
805 | } | |
806 | } | |
807 | ||
808 | return 0; | |
b119c6c9 | 809 | |
86ec5ec8 | 810 | out_err: |
b119c6c9 JD |
811 | dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " |
812 | "(%d)\n", client->name, client->addr, res); | |
77ed74da | 813 | return res; |
1da177e4 | 814 | } |
c0564606 | 815 | EXPORT_SYMBOL(i2c_attach_client); |
1da177e4 LT |
816 | |
817 | int i2c_detach_client(struct i2c_client *client) | |
818 | { | |
819 | struct i2c_adapter *adapter = client->adapter; | |
820 | int res = 0; | |
438d6c2c | 821 | |
1da177e4 LT |
822 | if (adapter->client_unregister) { |
823 | res = adapter->client_unregister(client); | |
824 | if (res) { | |
825 | dev_err(&client->dev, | |
86749e85 JD |
826 | "client_unregister [%s] failed, " |
827 | "client not detached\n", client->name); | |
1da177e4 LT |
828 | goto out; |
829 | } | |
830 | } | |
831 | ||
5c085d36 | 832 | mutex_lock(&adapter->clist_lock); |
1da177e4 | 833 | list_del(&client->list); |
9ddced16 JD |
834 | mutex_unlock(&adapter->clist_lock); |
835 | ||
1da177e4 | 836 | init_completion(&client->released); |
1da177e4 | 837 | device_unregister(&client->dev); |
1da177e4 LT |
838 | wait_for_completion(&client->released); |
839 | ||
840 | out: | |
841 | return res; | |
842 | } | |
c0564606 | 843 | EXPORT_SYMBOL(i2c_detach_client); |
1da177e4 | 844 | |
e48d3319 JD |
845 | /** |
846 | * i2c_use_client - increments the reference count of the i2c client structure | |
847 | * @client: the client being referenced | |
848 | * | |
849 | * Each live reference to a client should be refcounted. The driver model does | |
850 | * that automatically as part of driver binding, so that most drivers don't | |
851 | * need to do this explicitly: they hold a reference until they're unbound | |
852 | * from the device. | |
853 | * | |
854 | * A pointer to the client with the incremented reference counter is returned. | |
855 | */ | |
856 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 857 | { |
6ea438ec DB |
858 | if (client && get_device(&client->dev)) |
859 | return client; | |
860 | return NULL; | |
1da177e4 | 861 | } |
c0564606 | 862 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 863 | |
e48d3319 JD |
864 | /** |
865 | * i2c_release_client - release a use of the i2c client structure | |
866 | * @client: the client being no longer referenced | |
867 | * | |
868 | * Must be called when a user of a client is finished with it. | |
869 | */ | |
870 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 871 | { |
6ea438ec DB |
872 | if (client) |
873 | put_device(&client->dev); | |
1da177e4 | 874 | } |
c0564606 | 875 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 876 | |
9b766b81 DB |
877 | struct i2c_cmd_arg { |
878 | unsigned cmd; | |
879 | void *arg; | |
880 | }; | |
881 | ||
882 | static int i2c_cmd(struct device *dev, void *_arg) | |
883 | { | |
884 | struct i2c_client *client = i2c_verify_client(dev); | |
885 | struct i2c_cmd_arg *arg = _arg; | |
886 | ||
887 | if (client && client->driver && client->driver->command) | |
888 | client->driver->command(client, arg->cmd, arg->arg); | |
889 | return 0; | |
890 | } | |
891 | ||
1da177e4 LT |
892 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
893 | { | |
9b766b81 | 894 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 895 | |
9b766b81 DB |
896 | cmd_arg.cmd = cmd; |
897 | cmd_arg.arg = arg; | |
898 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 899 | } |
c0564606 | 900 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
901 | |
902 | static int __init i2c_init(void) | |
903 | { | |
904 | int retval; | |
905 | ||
906 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
907 | if (retval) |
908 | return retval; | |
e9f1373b DB |
909 | retval = class_register(&i2c_adapter_class); |
910 | if (retval) | |
911 | goto bus_err; | |
912 | retval = i2c_add_driver(&dummy_driver); | |
913 | if (retval) | |
914 | goto class_err; | |
915 | return 0; | |
916 | ||
917 | class_err: | |
918 | class_unregister(&i2c_adapter_class); | |
919 | bus_err: | |
920 | bus_unregister(&i2c_bus_type); | |
921 | return retval; | |
1da177e4 LT |
922 | } |
923 | ||
924 | static void __exit i2c_exit(void) | |
925 | { | |
e9f1373b | 926 | i2c_del_driver(&dummy_driver); |
1da177e4 | 927 | class_unregister(&i2c_adapter_class); |
1da177e4 LT |
928 | bus_unregister(&i2c_bus_type); |
929 | } | |
930 | ||
931 | subsys_initcall(i2c_init); | |
932 | module_exit(i2c_exit); | |
933 | ||
934 | /* ---------------------------------------------------- | |
935 | * the functional interface to the i2c busses. | |
936 | * ---------------------------------------------------- | |
937 | */ | |
938 | ||
a1cdedac DB |
939 | /** |
940 | * i2c_transfer - execute a single or combined I2C message | |
941 | * @adap: Handle to I2C bus | |
942 | * @msgs: One or more messages to execute before STOP is issued to | |
943 | * terminate the operation; each message begins with a START. | |
944 | * @num: Number of messages to be executed. | |
945 | * | |
946 | * Returns negative errno, else the number of messages executed. | |
947 | * | |
948 | * Note that there is no requirement that each message be sent to | |
949 | * the same slave address, although that is the most common model. | |
950 | */ | |
1da177e4 LT |
951 | int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) |
952 | { | |
953 | int ret; | |
954 | ||
a1cdedac DB |
955 | /* REVISIT the fault reporting model here is weak: |
956 | * | |
957 | * - When we get an error after receiving N bytes from a slave, | |
958 | * there is no way to report "N". | |
959 | * | |
960 | * - When we get a NAK after transmitting N bytes to a slave, | |
961 | * there is no way to report "N" ... or to let the master | |
962 | * continue executing the rest of this combined message, if | |
963 | * that's the appropriate response. | |
964 | * | |
965 | * - When for example "num" is two and we successfully complete | |
966 | * the first message but get an error part way through the | |
967 | * second, it's unclear whether that should be reported as | |
968 | * one (discarding status on the second message) or errno | |
969 | * (discarding status on the first one). | |
970 | */ | |
971 | ||
1da177e4 LT |
972 | if (adap->algo->master_xfer) { |
973 | #ifdef DEBUG | |
974 | for (ret = 0; ret < num; ret++) { | |
975 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
976 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
977 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
978 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
979 | } |
980 | #endif | |
981 | ||
cea443a8 MR |
982 | if (in_atomic() || irqs_disabled()) { |
983 | ret = mutex_trylock(&adap->bus_lock); | |
984 | if (!ret) | |
985 | /* I2C activity is ongoing. */ | |
986 | return -EAGAIN; | |
987 | } else { | |
988 | mutex_lock_nested(&adap->bus_lock, adap->level); | |
989 | } | |
990 | ||
1da177e4 | 991 | ret = adap->algo->master_xfer(adap,msgs,num); |
5c085d36 | 992 | mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
993 | |
994 | return ret; | |
995 | } else { | |
996 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 997 | return -EOPNOTSUPP; |
1da177e4 LT |
998 | } |
999 | } | |
c0564606 | 1000 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1001 | |
a1cdedac DB |
1002 | /** |
1003 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1004 | * @client: Handle to slave device | |
1005 | * @buf: Data that will be written to the slave | |
1006 | * @count: How many bytes to write | |
1007 | * | |
1008 | * Returns negative errno, or else the number of bytes written. | |
1009 | */ | |
1da177e4 LT |
1010 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1011 | { | |
1012 | int ret; | |
1013 | struct i2c_adapter *adap=client->adapter; | |
1014 | struct i2c_msg msg; | |
1015 | ||
815f55f2 JD |
1016 | msg.addr = client->addr; |
1017 | msg.flags = client->flags & I2C_M_TEN; | |
1018 | msg.len = count; | |
1019 | msg.buf = (char *)buf; | |
438d6c2c | 1020 | |
815f55f2 | 1021 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1022 | |
815f55f2 JD |
1023 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1024 | transmitted, else error code. */ | |
1025 | return (ret == 1) ? count : ret; | |
1da177e4 | 1026 | } |
c0564606 | 1027 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1028 | |
a1cdedac DB |
1029 | /** |
1030 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1031 | * @client: Handle to slave device | |
1032 | * @buf: Where to store data read from slave | |
1033 | * @count: How many bytes to read | |
1034 | * | |
1035 | * Returns negative errno, or else the number of bytes read. | |
1036 | */ | |
1da177e4 LT |
1037 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1038 | { | |
1039 | struct i2c_adapter *adap=client->adapter; | |
1040 | struct i2c_msg msg; | |
1041 | int ret; | |
815f55f2 JD |
1042 | |
1043 | msg.addr = client->addr; | |
1044 | msg.flags = client->flags & I2C_M_TEN; | |
1045 | msg.flags |= I2C_M_RD; | |
1046 | msg.len = count; | |
1047 | msg.buf = buf; | |
1048 | ||
1049 | ret = i2c_transfer(adap, &msg, 1); | |
1050 | ||
1051 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1052 | transmitted, else error code. */ | |
1053 | return (ret == 1) ? count : ret; | |
1da177e4 | 1054 | } |
c0564606 | 1055 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1056 | |
1da177e4 LT |
1057 | /* ---------------------------------------------------- |
1058 | * the i2c address scanning function | |
1059 | * Will not work for 10-bit addresses! | |
1060 | * ---------------------------------------------------- | |
1061 | */ | |
a89ba0bc JD |
1062 | static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, |
1063 | int (*found_proc) (struct i2c_adapter *, int, int)) | |
1064 | { | |
1065 | int err; | |
1066 | ||
1067 | /* Make sure the address is valid */ | |
1068 | if (addr < 0x03 || addr > 0x77) { | |
1069 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1070 | addr); | |
1071 | return -EINVAL; | |
9fc6adfa JD |
1072 | } |
1073 | ||
a89ba0bc JD |
1074 | /* Skip if already in use */ |
1075 | if (i2c_check_addr(adapter, addr)) | |
1076 | return 0; | |
1077 | ||
1078 | /* Make sure there is something at this address, unless forced */ | |
4c9337da JD |
1079 | if (kind < 0) { |
1080 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1081 | I2C_SMBUS_QUICK, NULL) < 0) | |
1082 | return 0; | |
1083 | ||
1084 | /* prevent 24RF08 corruption */ | |
1085 | if ((addr & ~0x0f) == 0x50) | |
1086 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1087 | I2C_SMBUS_QUICK, NULL); | |
1088 | } | |
a89ba0bc JD |
1089 | |
1090 | /* Finally call the custom detection function */ | |
1091 | err = found_proc(adapter, addr, kind); | |
a89ba0bc JD |
1092 | /* -ENODEV can be returned if there is a chip at the given address |
1093 | but it isn't supported by this chip driver. We catch it here as | |
1094 | this isn't an error. */ | |
114fd183 JD |
1095 | if (err == -ENODEV) |
1096 | err = 0; | |
1097 | ||
1098 | if (err) | |
1099 | dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n", | |
1100 | addr, err); | |
1101 | return err; | |
9fc6adfa JD |
1102 | } |
1103 | ||
1da177e4 | 1104 | int i2c_probe(struct i2c_adapter *adapter, |
bfb6df24 | 1105 | const struct i2c_client_address_data *address_data, |
1da177e4 LT |
1106 | int (*found_proc) (struct i2c_adapter *, int, int)) |
1107 | { | |
a89ba0bc | 1108 | int i, err; |
1da177e4 LT |
1109 | int adap_id = i2c_adapter_id(adapter); |
1110 | ||
a89ba0bc JD |
1111 | /* Force entries are done first, and are not affected by ignore |
1112 | entries */ | |
1113 | if (address_data->forces) { | |
bfb6df24 | 1114 | const unsigned short * const *forces = address_data->forces; |
a89ba0bc JD |
1115 | int kind; |
1116 | ||
1117 | for (kind = 0; forces[kind]; kind++) { | |
1118 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1119 | i += 2) { | |
1120 | if (forces[kind][i] == adap_id | |
1121 | || forces[kind][i] == ANY_I2C_BUS) { | |
1122 | dev_dbg(&adapter->dev, "found force " | |
1123 | "parameter for adapter %d, " | |
1124 | "addr 0x%02x, kind %d\n", | |
1125 | adap_id, forces[kind][i + 1], | |
1126 | kind); | |
1127 | err = i2c_probe_address(adapter, | |
1128 | forces[kind][i + 1], | |
1129 | kind, found_proc); | |
1130 | if (err) | |
1131 | return err; | |
1132 | } | |
1da177e4 LT |
1133 | } |
1134 | } | |
a89ba0bc | 1135 | } |
1da177e4 | 1136 | |
4366dc94 JD |
1137 | /* Stop here if we can't use SMBUS_QUICK */ |
1138 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1139 | if (address_data->probe[0] == I2C_CLIENT_END | |
1140 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
438d6c2c | 1141 | return 0; |
4366dc94 JD |
1142 | |
1143 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1144 | "can't probe for chips\n"); | |
24a5bb7b | 1145 | return -EOPNOTSUPP; |
4366dc94 JD |
1146 | } |
1147 | ||
a89ba0bc JD |
1148 | /* Probe entries are done second, and are not affected by ignore |
1149 | entries either */ | |
1150 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1151 | if (address_data->probe[i] == adap_id | |
1152 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1153 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1154 | "adapter %d, addr 0x%02x\n", adap_id, | |
1155 | address_data->probe[i + 1]); | |
1156 | err = i2c_probe_address(adapter, | |
1157 | address_data->probe[i + 1], | |
1158 | -1, found_proc); | |
1159 | if (err) | |
1160 | return err; | |
1da177e4 | 1161 | } |
a89ba0bc | 1162 | } |
1da177e4 | 1163 | |
a89ba0bc JD |
1164 | /* Normal entries are done last, unless shadowed by an ignore entry */ |
1165 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1166 | int j, ignore; | |
1167 | ||
1168 | ignore = 0; | |
1169 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1170 | j += 2) { | |
1171 | if ((address_data->ignore[j] == adap_id || | |
1172 | address_data->ignore[j] == ANY_I2C_BUS) | |
1173 | && address_data->ignore[j + 1] | |
1174 | == address_data->normal_i2c[i]) { | |
1175 | dev_dbg(&adapter->dev, "found ignore " | |
1176 | "parameter for adapter %d, " | |
1177 | "addr 0x%02x\n", adap_id, | |
1178 | address_data->ignore[j + 1]); | |
2369df93 MH |
1179 | ignore = 1; |
1180 | break; | |
1da177e4 LT |
1181 | } |
1182 | } | |
a89ba0bc | 1183 | if (ignore) |
1da177e4 LT |
1184 | continue; |
1185 | ||
a89ba0bc JD |
1186 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
1187 | "addr 0x%02x\n", adap_id, | |
1188 | address_data->normal_i2c[i]); | |
1189 | err = i2c_probe_address(adapter, address_data->normal_i2c[i], | |
1190 | -1, found_proc); | |
1191 | if (err) | |
1192 | return err; | |
1da177e4 | 1193 | } |
a89ba0bc | 1194 | |
1da177e4 LT |
1195 | return 0; |
1196 | } | |
c0564606 | 1197 | EXPORT_SYMBOL(i2c_probe); |
1da177e4 | 1198 | |
12b5053a JD |
1199 | struct i2c_client * |
1200 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1201 | struct i2c_board_info *info, | |
1202 | unsigned short const *addr_list) | |
1203 | { | |
1204 | int i; | |
1205 | ||
1206 | /* Stop here if the bus doesn't support probing */ | |
1207 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1208 | dev_err(&adap->dev, "Probing not supported\n"); | |
1209 | return NULL; | |
1210 | } | |
1211 | ||
12b5053a JD |
1212 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1213 | /* Check address validity */ | |
1214 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1215 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1216 | "0x%02x\n", addr_list[i]); | |
1217 | continue; | |
1218 | } | |
1219 | ||
1220 | /* Check address availability */ | |
9b766b81 | 1221 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1222 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1223 | "use, not probing\n", addr_list[i]); | |
1224 | continue; | |
1225 | } | |
1226 | ||
1227 | /* Test address responsiveness | |
1228 | The default probe method is a quick write, but it is known | |
1229 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1230 | and could also irreversibly write-protect some EEPROMs, so | |
1231 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1232 | read instead. Also, some bus drivers don't implement | |
1233 | quick write, so we fallback to a byte read it that case | |
1234 | too. */ | |
1235 | if ((addr_list[i] & ~0x07) == 0x30 | |
1236 | || (addr_list[i] & ~0x0f) == 0x50 | |
1237 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
1238 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1239 | I2C_SMBUS_READ, 0, | |
1240 | I2C_SMBUS_BYTE, NULL) >= 0) | |
1241 | break; | |
1242 | } else { | |
1243 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1244 | I2C_SMBUS_WRITE, 0, | |
1245 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1246 | break; | |
1247 | } | |
1248 | } | |
12b5053a JD |
1249 | |
1250 | if (addr_list[i] == I2C_CLIENT_END) { | |
1251 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1252 | return NULL; | |
1253 | } | |
1254 | ||
1255 | info->addr = addr_list[i]; | |
1256 | return i2c_new_device(adap, info); | |
1257 | } | |
1258 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1259 | ||
1da177e4 LT |
1260 | struct i2c_adapter* i2c_get_adapter(int id) |
1261 | { | |
1da177e4 | 1262 | struct i2c_adapter *adapter; |
438d6c2c | 1263 | |
caada32a | 1264 | mutex_lock(&core_lock); |
a0920e10 MH |
1265 | adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); |
1266 | if (adapter && !try_module_get(adapter->owner)) | |
1267 | adapter = NULL; | |
1268 | ||
caada32a | 1269 | mutex_unlock(&core_lock); |
a0920e10 | 1270 | return adapter; |
1da177e4 | 1271 | } |
c0564606 | 1272 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1273 | |
1274 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1275 | { | |
1276 | module_put(adap->owner); | |
1277 | } | |
c0564606 | 1278 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1279 | |
1280 | /* The SMBus parts */ | |
1281 | ||
438d6c2c | 1282 | #define POLY (0x1070U << 3) |
1da177e4 LT |
1283 | static u8 |
1284 | crc8(u16 data) | |
1285 | { | |
1286 | int i; | |
438d6c2c | 1287 | |
1da177e4 | 1288 | for(i = 0; i < 8; i++) { |
438d6c2c | 1289 | if (data & 0x8000) |
1da177e4 LT |
1290 | data = data ^ POLY; |
1291 | data = data << 1; | |
1292 | } | |
1293 | return (u8)(data >> 8); | |
1294 | } | |
1295 | ||
421ef47b JD |
1296 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1297 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1298 | { |
1299 | int i; | |
1300 | ||
1301 | for(i = 0; i < count; i++) | |
421ef47b | 1302 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1303 | return crc; |
1304 | } | |
1305 | ||
421ef47b JD |
1306 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1307 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1308 | { |
421ef47b JD |
1309 | /* The address will be sent first */ |
1310 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1311 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1312 | ||
1313 | /* The data buffer follows */ | |
1314 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1315 | } |
1316 | ||
421ef47b JD |
1317 | /* Used for write only transactions */ |
1318 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1319 | { |
421ef47b JD |
1320 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1321 | msg->len++; | |
1da177e4 LT |
1322 | } |
1323 | ||
421ef47b JD |
1324 | /* Return <0 on CRC error |
1325 | If there was a write before this read (most cases) we need to take the | |
1326 | partial CRC from the write part into account. | |
1327 | Note that this function does modify the message (we need to decrease the | |
1328 | message length to hide the CRC byte from the caller). */ | |
1329 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1330 | { |
421ef47b JD |
1331 | u8 rpec = msg->buf[--msg->len]; |
1332 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1333 | |
1da177e4 LT |
1334 | if (rpec != cpec) { |
1335 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1336 | rpec, cpec); | |
24a5bb7b | 1337 | return -EBADMSG; |
1da177e4 | 1338 | } |
438d6c2c | 1339 | return 0; |
1da177e4 LT |
1340 | } |
1341 | ||
a1cdedac DB |
1342 | /** |
1343 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1344 | * @client: Handle to slave device | |
1345 | * | |
1346 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1347 | * else the byte received from the device. | |
1348 | */ | |
1da177e4 LT |
1349 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1350 | { | |
1351 | union i2c_smbus_data data; | |
24a5bb7b DB |
1352 | int status; |
1353 | ||
1354 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1355 | I2C_SMBUS_READ, 0, | |
1356 | I2C_SMBUS_BYTE, &data); | |
1357 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1358 | } |
c0564606 | 1359 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1360 | |
a1cdedac DB |
1361 | /** |
1362 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1363 | * @client: Handle to slave device | |
1364 | * @value: Byte to be sent | |
1365 | * | |
1366 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1367 | * else zero on success. | |
1368 | */ | |
1da177e4 LT |
1369 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1370 | { | |
1da177e4 | 1371 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1372 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1373 | } |
c0564606 | 1374 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1375 | |
a1cdedac DB |
1376 | /** |
1377 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1378 | * @client: Handle to slave device | |
1379 | * @command: Byte interpreted by slave | |
1380 | * | |
1381 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1382 | * else a data byte received from the device. | |
1383 | */ | |
1da177e4 LT |
1384 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1385 | { | |
1386 | union i2c_smbus_data data; | |
24a5bb7b DB |
1387 | int status; |
1388 | ||
1389 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1390 | I2C_SMBUS_READ, command, | |
1391 | I2C_SMBUS_BYTE_DATA, &data); | |
1392 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1393 | } |
c0564606 | 1394 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1395 | |
a1cdedac DB |
1396 | /** |
1397 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1398 | * @client: Handle to slave device | |
1399 | * @command: Byte interpreted by slave | |
1400 | * @value: Byte being written | |
1401 | * | |
1402 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1403 | * else zero on success. | |
1404 | */ | |
1da177e4 LT |
1405 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1406 | { | |
1407 | union i2c_smbus_data data; | |
1408 | data.byte = value; | |
1409 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1410 | I2C_SMBUS_WRITE,command, | |
1411 | I2C_SMBUS_BYTE_DATA,&data); | |
1412 | } | |
c0564606 | 1413 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1414 | |
a1cdedac DB |
1415 | /** |
1416 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1417 | * @client: Handle to slave device | |
1418 | * @command: Byte interpreted by slave | |
1419 | * | |
1420 | * This executes the SMBus "read word" protocol, returning negative errno | |
1421 | * else a 16-bit unsigned "word" received from the device. | |
1422 | */ | |
1da177e4 LT |
1423 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1424 | { | |
1425 | union i2c_smbus_data data; | |
24a5bb7b DB |
1426 | int status; |
1427 | ||
1428 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1429 | I2C_SMBUS_READ, command, | |
1430 | I2C_SMBUS_WORD_DATA, &data); | |
1431 | return (status < 0) ? status : data.word; | |
1da177e4 | 1432 | } |
c0564606 | 1433 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1434 | |
a1cdedac DB |
1435 | /** |
1436 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1437 | * @client: Handle to slave device | |
1438 | * @command: Byte interpreted by slave | |
1439 | * @value: 16-bit "word" being written | |
1440 | * | |
1441 | * This executes the SMBus "write word" protocol, returning negative errno | |
1442 | * else zero on success. | |
1443 | */ | |
1da177e4 LT |
1444 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1445 | { | |
1446 | union i2c_smbus_data data; | |
1447 | data.word = value; | |
1448 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1449 | I2C_SMBUS_WRITE,command, | |
1450 | I2C_SMBUS_WORD_DATA,&data); | |
1451 | } | |
c0564606 | 1452 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1453 | |
a64ec07d | 1454 | /** |
a1cdedac | 1455 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1456 | * @client: Handle to slave device |
a1cdedac | 1457 | * @command: Byte interpreted by slave |
a64ec07d DB |
1458 | * @values: Byte array into which data will be read; big enough to hold |
1459 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1460 | * | |
a1cdedac DB |
1461 | * This executes the SMBus "block read" protocol, returning negative errno |
1462 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1463 | * |
1464 | * Note that using this function requires that the client's adapter support | |
1465 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1466 | * support this; its emulation through I2C messaging relies on a specific | |
1467 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1468 | */ | |
b86a1bc8 JD |
1469 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1470 | u8 *values) | |
1471 | { | |
1472 | union i2c_smbus_data data; | |
24a5bb7b | 1473 | int status; |
b86a1bc8 | 1474 | |
24a5bb7b DB |
1475 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1476 | I2C_SMBUS_READ, command, | |
1477 | I2C_SMBUS_BLOCK_DATA, &data); | |
1478 | if (status) | |
1479 | return status; | |
b86a1bc8 JD |
1480 | |
1481 | memcpy(values, &data.block[1], data.block[0]); | |
1482 | return data.block[0]; | |
1483 | } | |
1484 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1485 | ||
a1cdedac DB |
1486 | /** |
1487 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1488 | * @client: Handle to slave device | |
1489 | * @command: Byte interpreted by slave | |
1490 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1491 | * @values: Byte array which will be written. | |
1492 | * | |
1493 | * This executes the SMBus "block write" protocol, returning negative errno | |
1494 | * else zero on success. | |
1495 | */ | |
1da177e4 | 1496 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1497 | u8 length, const u8 *values) |
1da177e4 LT |
1498 | { |
1499 | union i2c_smbus_data data; | |
7656032b | 1500 | |
1da177e4 LT |
1501 | if (length > I2C_SMBUS_BLOCK_MAX) |
1502 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1503 | data.block[0] = length; |
7656032b | 1504 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1505 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1506 | I2C_SMBUS_WRITE,command, | |
1507 | I2C_SMBUS_BLOCK_DATA,&data); | |
1508 | } | |
c0564606 | 1509 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1510 | |
1511 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1512 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1513 | u8 length, u8 *values) | |
1da177e4 LT |
1514 | { |
1515 | union i2c_smbus_data data; | |
24a5bb7b | 1516 | int status; |
7656032b | 1517 | |
4b2643d7 JD |
1518 | if (length > I2C_SMBUS_BLOCK_MAX) |
1519 | length = I2C_SMBUS_BLOCK_MAX; | |
1520 | data.block[0] = length; | |
24a5bb7b DB |
1521 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1522 | I2C_SMBUS_READ, command, | |
1523 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1524 | if (status < 0) | |
1525 | return status; | |
7656032b JD |
1526 | |
1527 | memcpy(values, &data.block[1], data.block[0]); | |
1528 | return data.block[0]; | |
1da177e4 | 1529 | } |
c0564606 | 1530 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1531 | |
21bbd691 | 1532 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1533 | u8 length, const u8 *values) |
21bbd691 JD |
1534 | { |
1535 | union i2c_smbus_data data; | |
1536 | ||
1537 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1538 | length = I2C_SMBUS_BLOCK_MAX; | |
1539 | data.block[0] = length; | |
1540 | memcpy(data.block + 1, values, length); | |
1541 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1542 | I2C_SMBUS_WRITE, command, | |
1543 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1544 | } | |
c0564606 | 1545 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1546 | |
438d6c2c | 1547 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1548 | No checking of parameters is done! */ |
438d6c2c | 1549 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1550 | unsigned short flags, |
438d6c2c | 1551 | char read_write, u8 command, int size, |
1da177e4 LT |
1552 | union i2c_smbus_data * data) |
1553 | { | |
1554 | /* So we need to generate a series of msgs. In the case of writing, we | |
1555 | need to use only one message; when reading, we need two. We initialize | |
1556 | most things with sane defaults, to keep the code below somewhat | |
1557 | simpler. */ | |
5c50d188 HI |
1558 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1559 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1560 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1561 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1562 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1563 | }; | |
1564 | int i; | |
421ef47b | 1565 | u8 partial_pec = 0; |
24a5bb7b | 1566 | int status; |
1da177e4 LT |
1567 | |
1568 | msgbuf0[0] = command; | |
1569 | switch(size) { | |
1570 | case I2C_SMBUS_QUICK: | |
1571 | msg[0].len = 0; | |
1572 | /* Special case: The read/write field is used as data */ | |
1573 | msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0; | |
1574 | num = 1; | |
1575 | break; | |
1576 | case I2C_SMBUS_BYTE: | |
1577 | if (read_write == I2C_SMBUS_READ) { | |
1578 | /* Special case: only a read! */ | |
1579 | msg[0].flags = I2C_M_RD | flags; | |
1580 | num = 1; | |
1581 | } | |
1582 | break; | |
1583 | case I2C_SMBUS_BYTE_DATA: | |
1584 | if (read_write == I2C_SMBUS_READ) | |
1585 | msg[1].len = 1; | |
1586 | else { | |
1587 | msg[0].len = 2; | |
1588 | msgbuf0[1] = data->byte; | |
1589 | } | |
1590 | break; | |
1591 | case I2C_SMBUS_WORD_DATA: | |
1592 | if (read_write == I2C_SMBUS_READ) | |
1593 | msg[1].len = 2; | |
1594 | else { | |
1595 | msg[0].len=3; | |
1596 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1597 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1598 | } |
1599 | break; | |
1600 | case I2C_SMBUS_PROC_CALL: | |
1601 | num = 2; /* Special case */ | |
1602 | read_write = I2C_SMBUS_READ; | |
1603 | msg[0].len = 3; | |
1604 | msg[1].len = 2; | |
1605 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1606 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1607 | break; |
1608 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1609 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1610 | msg[1].flags |= I2C_M_RECV_LEN; |
1611 | msg[1].len = 1; /* block length will be added by | |
1612 | the underlying bus driver */ | |
1da177e4 LT |
1613 | } else { |
1614 | msg[0].len = data->block[0] + 2; | |
1615 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1616 | dev_err(&adapter->dev, |
1617 | "Invalid block write size %d\n", | |
1618 | data->block[0]); | |
1619 | return -EINVAL; | |
1da177e4 | 1620 | } |
5c50d188 | 1621 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1622 | msgbuf0[i] = data->block[i-1]; |
1623 | } | |
1624 | break; | |
1625 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1626 | num = 2; /* Another special case */ |
1627 | read_write = I2C_SMBUS_READ; | |
1628 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1629 | dev_err(&adapter->dev, |
1630 | "Invalid block write size %d\n", | |
209d27c3 | 1631 | data->block[0]); |
24a5bb7b | 1632 | return -EINVAL; |
209d27c3 JD |
1633 | } |
1634 | msg[0].len = data->block[0] + 2; | |
1635 | for (i = 1; i < msg[0].len; i++) | |
1636 | msgbuf0[i] = data->block[i-1]; | |
1637 | msg[1].flags |= I2C_M_RECV_LEN; | |
1638 | msg[1].len = 1; /* block length will be added by | |
1639 | the underlying bus driver */ | |
1640 | break; | |
1da177e4 LT |
1641 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1642 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1643 | msg[1].len = data->block[0]; |
1da177e4 LT |
1644 | } else { |
1645 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1646 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1647 | dev_err(&adapter->dev, |
1648 | "Invalid block write size %d\n", | |
1649 | data->block[0]); | |
1650 | return -EINVAL; | |
1da177e4 LT |
1651 | } |
1652 | for (i = 1; i <= data->block[0]; i++) | |
1653 | msgbuf0[i] = data->block[i]; | |
1654 | } | |
1655 | break; | |
1656 | default: | |
24a5bb7b DB |
1657 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1658 | return -EOPNOTSUPP; | |
1da177e4 LT |
1659 | } |
1660 | ||
421ef47b JD |
1661 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1662 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1663 | if (i) { | |
1664 | /* Compute PEC if first message is a write */ | |
1665 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1666 | if (num == 1) /* Write only */ |
421ef47b JD |
1667 | i2c_smbus_add_pec(&msg[0]); |
1668 | else /* Write followed by read */ | |
1669 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1670 | } | |
1671 | /* Ask for PEC if last message is a read */ | |
1672 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1673 | msg[num-1].len++; |
421ef47b JD |
1674 | } |
1675 | ||
24a5bb7b DB |
1676 | status = i2c_transfer(adapter, msg, num); |
1677 | if (status < 0) | |
1678 | return status; | |
1da177e4 | 1679 | |
421ef47b JD |
1680 | /* Check PEC if last message is a read */ |
1681 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1682 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1683 | if (status < 0) | |
1684 | return status; | |
421ef47b JD |
1685 | } |
1686 | ||
1da177e4 LT |
1687 | if (read_write == I2C_SMBUS_READ) |
1688 | switch(size) { | |
1689 | case I2C_SMBUS_BYTE: | |
1690 | data->byte = msgbuf0[0]; | |
1691 | break; | |
1692 | case I2C_SMBUS_BYTE_DATA: | |
1693 | data->byte = msgbuf1[0]; | |
1694 | break; | |
438d6c2c | 1695 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1696 | case I2C_SMBUS_PROC_CALL: |
1697 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1698 | break; | |
1699 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1700 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1701 | data->block[i+1] = msgbuf1[i]; |
1702 | break; | |
209d27c3 JD |
1703 | case I2C_SMBUS_BLOCK_DATA: |
1704 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1705 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1706 | data->block[i] = msgbuf1[i]; | |
1707 | break; | |
1da177e4 LT |
1708 | } |
1709 | return 0; | |
1710 | } | |
1711 | ||
a1cdedac DB |
1712 | /** |
1713 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1714 | * @adapter: Handle to I2C bus | |
1715 | * @addr: Address of SMBus slave on that bus | |
1716 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1717 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1718 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1719 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1720 | * @data: Data to be read or written | |
1721 | * | |
1722 | * This executes an SMBus protocol operation, and returns a negative | |
1723 | * errno code else zero on success. | |
1724 | */ | |
1da177e4 | 1725 | s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, |
a1cdedac | 1726 | char read_write, u8 command, int protocol, |
1da177e4 LT |
1727 | union i2c_smbus_data * data) |
1728 | { | |
1729 | s32 res; | |
1da177e4 LT |
1730 | |
1731 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1732 | |
1733 | if (adapter->algo->smbus_xfer) { | |
5c085d36 | 1734 | mutex_lock(&adapter->bus_lock); |
1da177e4 | 1735 | res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, |
a1cdedac | 1736 | command, protocol, data); |
5c085d36 | 1737 | mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1738 | } else |
1739 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1740 | command, protocol, data); |
1da177e4 | 1741 | |
1da177e4 LT |
1742 | return res; |
1743 | } | |
1da177e4 | 1744 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1745 | |
1746 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1747 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1748 | MODULE_LICENSE("GPL"); |