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Commit | Line | Data |
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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 | ||
e9ca9eb9 | 204 | 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 | 214 | }; |
e9ca9eb9 | 215 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 216 | |
9b766b81 DB |
217 | |
218 | /** | |
219 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
220 | * @dev: device, probably from some driver model iterator | |
221 | * | |
222 | * When traversing the driver model tree, perhaps using driver model | |
223 | * iterators like @device_for_each_child(), you can't assume very much | |
224 | * about the nodes you find. Use this function to avoid oopses caused | |
225 | * by wrongly treating some non-I2C device as an i2c_client. | |
226 | */ | |
227 | struct i2c_client *i2c_verify_client(struct device *dev) | |
228 | { | |
229 | return (dev->bus == &i2c_bus_type) | |
230 | ? to_i2c_client(dev) | |
231 | : NULL; | |
232 | } | |
233 | EXPORT_SYMBOL(i2c_verify_client); | |
234 | ||
235 | ||
9c1600ed DB |
236 | /** |
237 | * i2c_new_device - instantiate an i2c device for use with a new style driver | |
238 | * @adap: the adapter managing the device | |
239 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 240 | * Context: can sleep |
9c1600ed DB |
241 | * |
242 | * Create a device to work with a new style i2c driver, where binding is | |
243 | * handled through driver model probe()/remove() methods. This call is not | |
244 | * appropriate for use by mainboad initialization logic, which usually runs | |
245 | * during an arch_initcall() long before any i2c_adapter could exist. | |
246 | * | |
247 | * This returns the new i2c client, which may be saved for later use with | |
248 | * i2c_unregister_device(); or NULL to indicate an error. | |
249 | */ | |
250 | struct i2c_client * | |
251 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
252 | { | |
253 | struct i2c_client *client; | |
254 | int status; | |
255 | ||
256 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
257 | if (!client) | |
258 | return NULL; | |
259 | ||
260 | client->adapter = adap; | |
261 | ||
262 | client->dev.platform_data = info->platform_data; | |
3bbb835d DB |
263 | device_init_wakeup(&client->dev, info->flags & I2C_CLIENT_WAKE); |
264 | ||
265 | client->flags = info->flags & ~I2C_CLIENT_WAKE; | |
9c1600ed DB |
266 | client->addr = info->addr; |
267 | client->irq = info->irq; | |
268 | ||
9c1600ed DB |
269 | strlcpy(client->name, info->type, sizeof(client->name)); |
270 | ||
271 | /* a new style driver may be bound to this device when we | |
272 | * return from this function, or any later moment (e.g. maybe | |
273 | * hotplugging will load the driver module). and the device | |
274 | * refcount model is the standard driver model one. | |
275 | */ | |
276 | status = i2c_attach_client(client); | |
277 | if (status < 0) { | |
278 | kfree(client); | |
279 | client = NULL; | |
280 | } | |
281 | return client; | |
282 | } | |
283 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
284 | ||
285 | ||
286 | /** | |
287 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
288 | * @client: value returned from i2c_new_device() | |
d64f73be | 289 | * Context: can sleep |
9c1600ed DB |
290 | */ |
291 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 DB |
292 | { |
293 | struct i2c_adapter *adapter = client->adapter; | |
294 | struct i2c_driver *driver = client->driver; | |
295 | ||
296 | if (driver && !is_newstyle_driver(driver)) { | |
297 | dev_err(&client->dev, "can't unregister devices " | |
298 | "with legacy drivers\n"); | |
299 | WARN_ON(1); | |
300 | return; | |
301 | } | |
302 | ||
8508159e JD |
303 | if (adapter->client_unregister) { |
304 | if (adapter->client_unregister(client)) { | |
305 | dev_warn(&client->dev, | |
306 | "client_unregister [%s] failed\n", | |
307 | client->name); | |
308 | } | |
309 | } | |
310 | ||
a1d9e6e4 DB |
311 | mutex_lock(&adapter->clist_lock); |
312 | list_del(&client->list); | |
313 | mutex_unlock(&adapter->clist_lock); | |
314 | ||
315 | device_unregister(&client->dev); | |
316 | } | |
9c1600ed | 317 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
318 | |
319 | ||
60b129d7 JD |
320 | static const struct i2c_device_id dummy_id[] = { |
321 | { "dummy", 0 }, | |
322 | { }, | |
323 | }; | |
324 | ||
d2653e92 JD |
325 | static int dummy_probe(struct i2c_client *client, |
326 | const struct i2c_device_id *id) | |
327 | { | |
328 | return 0; | |
329 | } | |
330 | ||
331 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
332 | { |
333 | return 0; | |
334 | } | |
335 | ||
336 | static struct i2c_driver dummy_driver = { | |
337 | .driver.name = "dummy", | |
d2653e92 JD |
338 | .probe = dummy_probe, |
339 | .remove = dummy_remove, | |
60b129d7 | 340 | .id_table = dummy_id, |
e9f1373b DB |
341 | }; |
342 | ||
343 | /** | |
344 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
345 | * @adapter: the adapter managing the device | |
346 | * @address: seven bit address to be used | |
e9f1373b DB |
347 | * Context: can sleep |
348 | * | |
349 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
350 | * with devices that consume multiple addresses. Examples of such chips | |
351 | * include various EEPROMS (like 24c04 and 24c08 models). | |
352 | * | |
353 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
354 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
355 | * And second, this prevents the specified address from being bound to a | |
356 | * different driver. | |
357 | * | |
358 | * This returns the new i2c client, which should be saved for later use with | |
359 | * i2c_unregister_device(); or NULL to indicate an error. | |
360 | */ | |
361 | struct i2c_client * | |
60b129d7 | 362 | i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
363 | { |
364 | struct i2c_board_info info = { | |
60b129d7 | 365 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
366 | }; |
367 | ||
e9f1373b DB |
368 | return i2c_new_device(adapter, &info); |
369 | } | |
370 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
371 | ||
f37dd80a DB |
372 | /* ------------------------------------------------------------------------- */ |
373 | ||
16ffadfc DB |
374 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
375 | ||
83eaaed0 | 376 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 377 | { |
ef2c8321 | 378 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
379 | complete(&adap->dev_released); |
380 | } | |
381 | ||
16ffadfc DB |
382 | static ssize_t |
383 | show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) | |
384 | { | |
ef2c8321 | 385 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
16ffadfc DB |
386 | return sprintf(buf, "%s\n", adap->name); |
387 | } | |
b119dc3f | 388 | |
16ffadfc DB |
389 | static struct device_attribute i2c_adapter_attrs[] = { |
390 | __ATTR(name, S_IRUGO, show_adapter_name, NULL), | |
391 | { }, | |
392 | }; | |
b119dc3f | 393 | |
83eaaed0 | 394 | static struct class i2c_adapter_class = { |
b119dc3f DB |
395 | .owner = THIS_MODULE, |
396 | .name = "i2c-adapter", | |
16ffadfc | 397 | .dev_attrs = i2c_adapter_attrs, |
1da177e4 LT |
398 | }; |
399 | ||
9c1600ed DB |
400 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
401 | { | |
402 | struct i2c_devinfo *devinfo; | |
403 | ||
404 | mutex_lock(&__i2c_board_lock); | |
405 | list_for_each_entry(devinfo, &__i2c_board_list, list) { | |
406 | if (devinfo->busnum == adapter->nr | |
407 | && !i2c_new_device(adapter, | |
408 | &devinfo->board_info)) | |
409 | printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n", | |
410 | i2c_adapter_id(adapter), | |
411 | devinfo->board_info.addr); | |
412 | } | |
413 | mutex_unlock(&__i2c_board_lock); | |
414 | } | |
415 | ||
026526f5 JD |
416 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
417 | { | |
418 | struct i2c_driver *driver = to_i2c_driver(d); | |
419 | struct i2c_adapter *adap = data; | |
420 | ||
421 | if (driver->attach_adapter) { | |
422 | /* We ignore the return code; if it fails, too bad */ | |
423 | driver->attach_adapter(adap); | |
424 | } | |
425 | return 0; | |
426 | } | |
427 | ||
6e13e641 | 428 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 429 | { |
026526f5 | 430 | int res = 0, dummy; |
1da177e4 | 431 | |
5c085d36 IM |
432 | mutex_init(&adap->bus_lock); |
433 | mutex_init(&adap->clist_lock); | |
1da177e4 LT |
434 | INIT_LIST_HEAD(&adap->clients); |
435 | ||
caada32a | 436 | mutex_lock(&core_lock); |
6e13e641 | 437 | |
1da177e4 LT |
438 | /* Add the adapter to the driver core. |
439 | * If the parent pointer is not set up, | |
440 | * we add this adapter to the host bus. | |
441 | */ | |
b119dc3f | 442 | if (adap->dev.parent == NULL) { |
1da177e4 | 443 | adap->dev.parent = &platform_bus; |
fe2c8d51 JD |
444 | pr_debug("I2C adapter driver [%s] forgot to specify " |
445 | "physical device\n", adap->name); | |
b119dc3f | 446 | } |
1da177e4 | 447 | sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); |
1da177e4 | 448 | adap->dev.release = &i2c_adapter_dev_release; |
fccb56e4 | 449 | adap->dev.class = &i2c_adapter_class; |
b119c6c9 JD |
450 | res = device_register(&adap->dev); |
451 | if (res) | |
452 | goto out_list; | |
1da177e4 | 453 | |
b6d7b3d1 JD |
454 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
455 | ||
6e13e641 DB |
456 | /* create pre-declared device nodes for new-style drivers */ |
457 | if (adap->nr < __i2c_first_dynamic_bus_num) | |
458 | i2c_scan_static_board_info(adap); | |
459 | ||
7b4fbc50 | 460 | /* let legacy drivers scan this bus for matching devices */ |
026526f5 JD |
461 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
462 | i2c_do_add_adapter); | |
1da177e4 | 463 | |
1da177e4 | 464 | out_unlock: |
caada32a | 465 | mutex_unlock(&core_lock); |
1da177e4 | 466 | return res; |
b119c6c9 | 467 | |
b119c6c9 | 468 | out_list: |
b119c6c9 JD |
469 | idr_remove(&i2c_adapter_idr, adap->nr); |
470 | goto out_unlock; | |
1da177e4 LT |
471 | } |
472 | ||
6e13e641 DB |
473 | /** |
474 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
475 | * @adapter: the adapter to add | |
d64f73be | 476 | * Context: can sleep |
6e13e641 DB |
477 | * |
478 | * This routine is used to declare an I2C adapter when its bus number | |
479 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
480 | * USB links or PCI plugin cards. | |
481 | * | |
482 | * When this returns zero, a new bus number was allocated and stored | |
483 | * in adap->nr, and the specified adapter became available for clients. | |
484 | * Otherwise, a negative errno value is returned. | |
485 | */ | |
486 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
487 | { | |
488 | int id, res = 0; | |
489 | ||
490 | retry: | |
491 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
492 | return -ENOMEM; | |
493 | ||
caada32a | 494 | mutex_lock(&core_lock); |
6e13e641 DB |
495 | /* "above" here means "above or equal to", sigh */ |
496 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
497 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 498 | mutex_unlock(&core_lock); |
6e13e641 DB |
499 | |
500 | if (res < 0) { | |
501 | if (res == -EAGAIN) | |
502 | goto retry; | |
503 | return res; | |
504 | } | |
505 | ||
506 | adapter->nr = id; | |
507 | return i2c_register_adapter(adapter); | |
508 | } | |
509 | EXPORT_SYMBOL(i2c_add_adapter); | |
510 | ||
511 | /** | |
512 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
513 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 514 | * Context: can sleep |
6e13e641 DB |
515 | * |
516 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
517 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
518 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
519 | * is used to properly configure I2C devices. |
520 | * | |
521 | * If no devices have pre-been declared for this bus, then be sure to | |
522 | * register the adapter before any dynamically allocated ones. Otherwise | |
523 | * the required bus ID may not be available. | |
524 | * | |
525 | * When this returns zero, the specified adapter became available for | |
526 | * clients using the bus number provided in adap->nr. Also, the table | |
527 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
528 | * and the appropriate driver model device nodes are created. Otherwise, a | |
529 | * negative errno value is returned. | |
530 | */ | |
531 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
532 | { | |
533 | int id; | |
534 | int status; | |
535 | ||
536 | if (adap->nr & ~MAX_ID_MASK) | |
537 | return -EINVAL; | |
538 | ||
539 | retry: | |
540 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
541 | return -ENOMEM; | |
542 | ||
caada32a | 543 | mutex_lock(&core_lock); |
6e13e641 DB |
544 | /* "above" here means "above or equal to", sigh; |
545 | * we need the "equal to" result to force the result | |
546 | */ | |
547 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
548 | if (status == 0 && id != adap->nr) { | |
549 | status = -EBUSY; | |
550 | idr_remove(&i2c_adapter_idr, id); | |
551 | } | |
caada32a | 552 | mutex_unlock(&core_lock); |
6e13e641 DB |
553 | if (status == -EAGAIN) |
554 | goto retry; | |
555 | ||
556 | if (status == 0) | |
557 | status = i2c_register_adapter(adap); | |
558 | return status; | |
559 | } | |
560 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
561 | ||
026526f5 JD |
562 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
563 | { | |
564 | struct i2c_driver *driver = to_i2c_driver(d); | |
565 | struct i2c_adapter *adapter = data; | |
566 | int res; | |
567 | ||
568 | if (!driver->detach_adapter) | |
569 | return 0; | |
570 | res = driver->detach_adapter(adapter); | |
571 | if (res) | |
572 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
573 | "for driver [%s]\n", res, driver->driver.name); | |
574 | return res; | |
575 | } | |
576 | ||
d64f73be DB |
577 | /** |
578 | * i2c_del_adapter - unregister I2C adapter | |
579 | * @adap: the adapter being unregistered | |
580 | * Context: can sleep | |
581 | * | |
582 | * This unregisters an I2C adapter which was previously registered | |
583 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
584 | */ | |
1da177e4 LT |
585 | int i2c_del_adapter(struct i2c_adapter *adap) |
586 | { | |
6a03cd93 | 587 | struct i2c_client *client, *_n; |
1da177e4 LT |
588 | int res = 0; |
589 | ||
caada32a | 590 | mutex_lock(&core_lock); |
1da177e4 LT |
591 | |
592 | /* First make sure that this adapter was ever added */ | |
87c6c229 | 593 | if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { |
b6d7b3d1 JD |
594 | pr_debug("i2c-core: attempting to delete unregistered " |
595 | "adapter [%s]\n", adap->name); | |
1da177e4 LT |
596 | res = -EINVAL; |
597 | goto out_unlock; | |
598 | } | |
599 | ||
026526f5 JD |
600 | /* Tell drivers about this removal */ |
601 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, | |
602 | i2c_do_del_adapter); | |
603 | if (res) | |
604 | goto out_unlock; | |
1da177e4 LT |
605 | |
606 | /* detach any active clients. This must be done first, because | |
a551acc2 | 607 | * it can fail; in which case we give up. */ |
6a03cd93 | 608 | list_for_each_entry_safe(client, _n, &adap->clients, list) { |
a1d9e6e4 DB |
609 | struct i2c_driver *driver; |
610 | ||
a1d9e6e4 DB |
611 | driver = client->driver; |
612 | ||
613 | /* new style, follow standard driver model */ | |
614 | if (!driver || is_newstyle_driver(driver)) { | |
615 | i2c_unregister_device(client); | |
616 | continue; | |
617 | } | |
1da177e4 | 618 | |
a1d9e6e4 DB |
619 | /* legacy drivers create and remove clients themselves */ |
620 | if ((res = driver->detach_client(client))) { | |
b6d7b3d1 JD |
621 | dev_err(&adap->dev, "detach_client failed for client " |
622 | "[%s] at address 0x%02x\n", client->name, | |
1da177e4 LT |
623 | client->addr); |
624 | goto out_unlock; | |
625 | } | |
626 | } | |
627 | ||
628 | /* clean up the sysfs representation */ | |
629 | init_completion(&adap->dev_released); | |
1da177e4 | 630 | device_unregister(&adap->dev); |
1da177e4 LT |
631 | |
632 | /* wait for sysfs to drop all references */ | |
633 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 634 | |
6e13e641 | 635 | /* free bus id */ |
1da177e4 LT |
636 | idr_remove(&i2c_adapter_idr, adap->nr); |
637 | ||
b6d7b3d1 | 638 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 LT |
639 | |
640 | out_unlock: | |
caada32a | 641 | mutex_unlock(&core_lock); |
1da177e4 LT |
642 | return res; |
643 | } | |
c0564606 | 644 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
645 | |
646 | ||
7b4fbc50 DB |
647 | /* ------------------------------------------------------------------------- */ |
648 | ||
7f101a97 DY |
649 | static int __attach_adapter(struct device *dev, void *data) |
650 | { | |
651 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
652 | struct i2c_driver *driver = data; | |
653 | ||
654 | driver->attach_adapter(adapter); | |
655 | ||
656 | return 0; | |
657 | } | |
658 | ||
7b4fbc50 DB |
659 | /* |
660 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
661 | * i2c slave chips, on a bus instance associated with some i2c_adapter. There | |
662 | * are two models for binding the driver to its device: "new style" drivers | |
663 | * follow the standard Linux driver model and just respond to probe() calls | |
664 | * issued if the driver core sees they match(); "legacy" drivers create device | |
665 | * nodes themselves. | |
1da177e4 LT |
666 | */ |
667 | ||
de59cf9e | 668 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 669 | { |
7eebcb7c | 670 | int res; |
1da177e4 | 671 | |
7b4fbc50 | 672 | /* new style driver methods can't mix with legacy ones */ |
a1d9e6e4 | 673 | if (is_newstyle_driver(driver)) { |
7b4fbc50 DB |
674 | if (driver->attach_adapter || driver->detach_adapter |
675 | || driver->detach_client) { | |
676 | printk(KERN_WARNING | |
677 | "i2c-core: driver [%s] is confused\n", | |
678 | driver->driver.name); | |
679 | return -EINVAL; | |
680 | } | |
681 | } | |
682 | ||
1da177e4 | 683 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 684 | driver->driver.owner = owner; |
1da177e4 | 685 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 686 | |
6e13e641 DB |
687 | /* for new style drivers, when registration returns the driver core |
688 | * will have called probe() for all matching-but-unbound devices. | |
689 | */ | |
1da177e4 LT |
690 | res = driver_register(&driver->driver); |
691 | if (res) | |
7eebcb7c | 692 | return res; |
438d6c2c | 693 | |
caada32a | 694 | mutex_lock(&core_lock); |
7eebcb7c | 695 | |
35d8b2e6 | 696 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 697 | |
7b4fbc50 | 698 | /* legacy drivers scan i2c busses directly */ |
7f101a97 DY |
699 | if (driver->attach_adapter) |
700 | class_for_each_device(&i2c_adapter_class, driver, | |
701 | __attach_adapter); | |
4ad4eac6 | 702 | |
7f101a97 DY |
703 | mutex_unlock(&core_lock); |
704 | return 0; | |
705 | } | |
706 | EXPORT_SYMBOL(i2c_register_driver); | |
707 | ||
708 | static int __detach_adapter(struct device *dev, void *data) | |
709 | { | |
710 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
711 | struct i2c_driver *driver = data; | |
712 | ||
713 | /* Have a look at each adapter, if clients of this driver are still | |
714 | * attached. If so, detach them to be able to kill the driver | |
715 | * afterwards. | |
716 | */ | |
717 | if (driver->detach_adapter) { | |
718 | if (driver->detach_adapter(adapter)) | |
719 | dev_err(&adapter->dev, | |
720 | "detach_adapter failed for driver [%s]\n", | |
721 | driver->driver.name); | |
722 | } else { | |
6a03cd93 | 723 | struct i2c_client *client, *_n; |
7f101a97 | 724 | |
6a03cd93 | 725 | list_for_each_entry_safe(client, _n, &adapter->clients, list) { |
7f101a97 DY |
726 | if (client->driver != driver) |
727 | continue; | |
728 | dev_dbg(&adapter->dev, | |
729 | "detaching client [%s] at 0x%02x\n", | |
730 | client->name, client->addr); | |
731 | if (driver->detach_client(client)) | |
732 | dev_err(&adapter->dev, "detach_client " | |
733 | "failed for client [%s] at 0x%02x\n", | |
734 | client->name, client->addr); | |
1da177e4 LT |
735 | } |
736 | } | |
737 | ||
7eebcb7c | 738 | return 0; |
1da177e4 LT |
739 | } |
740 | ||
a1d9e6e4 DB |
741 | /** |
742 | * i2c_del_driver - unregister I2C driver | |
743 | * @driver: the driver being unregistered | |
d64f73be | 744 | * Context: can sleep |
a1d9e6e4 | 745 | */ |
b3e82096 | 746 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 747 | { |
caada32a | 748 | mutex_lock(&core_lock); |
1da177e4 | 749 | |
f7050bd7 JD |
750 | /* legacy driver? */ |
751 | if (!is_newstyle_driver(driver)) | |
752 | class_for_each_device(&i2c_adapter_class, driver, | |
753 | __detach_adapter); | |
1da177e4 LT |
754 | |
755 | driver_unregister(&driver->driver); | |
35d8b2e6 | 756 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 757 | |
caada32a | 758 | mutex_unlock(&core_lock); |
1da177e4 | 759 | } |
c0564606 | 760 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 761 | |
7b4fbc50 DB |
762 | /* ------------------------------------------------------------------------- */ |
763 | ||
9b766b81 | 764 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 765 | { |
9b766b81 DB |
766 | struct i2c_client *client = i2c_verify_client(dev); |
767 | int addr = *(int *)addrp; | |
1da177e4 | 768 | |
9b766b81 DB |
769 | if (client && client->addr == addr) |
770 | return -EBUSY; | |
1da177e4 LT |
771 | return 0; |
772 | } | |
773 | ||
5e31c2bd | 774 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 775 | { |
9b766b81 | 776 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
777 | } |
778 | ||
779 | int i2c_attach_client(struct i2c_client *client) | |
780 | { | |
781 | struct i2c_adapter *adapter = client->adapter; | |
b119c6c9 | 782 | int res = 0; |
1da177e4 | 783 | |
1da177e4 | 784 | client->dev.parent = &client->adapter->dev; |
1da177e4 | 785 | client->dev.bus = &i2c_bus_type; |
9c1600ed DB |
786 | |
787 | if (client->driver) | |
788 | client->dev.driver = &client->driver->driver; | |
789 | ||
de81d2aa | 790 | if (client->driver && !is_newstyle_driver(client->driver)) { |
9c1600ed | 791 | client->dev.release = i2c_client_release; |
de81d2aa DB |
792 | client->dev.uevent_suppress = 1; |
793 | } else | |
9c1600ed | 794 | client->dev.release = i2c_client_dev_release; |
438d6c2c | 795 | |
1da177e4 LT |
796 | snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), |
797 | "%d-%04x", i2c_adapter_id(adapter), client->addr); | |
b119c6c9 JD |
798 | res = device_register(&client->dev); |
799 | if (res) | |
86ec5ec8 DB |
800 | goto out_err; |
801 | ||
802 | mutex_lock(&adapter->clist_lock); | |
803 | list_add_tail(&client->list, &adapter->clients); | |
b119c6c9 | 804 | mutex_unlock(&adapter->clist_lock); |
77ed74da | 805 | |
86ec5ec8 DB |
806 | dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", |
807 | client->name, client->dev.bus_id); | |
808 | ||
77ed74da JD |
809 | if (adapter->client_register) { |
810 | if (adapter->client_register(client)) { | |
811 | dev_dbg(&adapter->dev, "client_register " | |
812 | "failed for client [%s] at 0x%02x\n", | |
813 | client->name, client->addr); | |
814 | } | |
815 | } | |
816 | ||
817 | return 0; | |
b119c6c9 | 818 | |
86ec5ec8 | 819 | out_err: |
b119c6c9 JD |
820 | dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " |
821 | "(%d)\n", client->name, client->addr, res); | |
77ed74da | 822 | return res; |
1da177e4 | 823 | } |
c0564606 | 824 | EXPORT_SYMBOL(i2c_attach_client); |
1da177e4 LT |
825 | |
826 | int i2c_detach_client(struct i2c_client *client) | |
827 | { | |
828 | struct i2c_adapter *adapter = client->adapter; | |
829 | int res = 0; | |
438d6c2c | 830 | |
1da177e4 LT |
831 | if (adapter->client_unregister) { |
832 | res = adapter->client_unregister(client); | |
833 | if (res) { | |
834 | dev_err(&client->dev, | |
86749e85 JD |
835 | "client_unregister [%s] failed, " |
836 | "client not detached\n", client->name); | |
1da177e4 LT |
837 | goto out; |
838 | } | |
839 | } | |
840 | ||
5c085d36 | 841 | mutex_lock(&adapter->clist_lock); |
1da177e4 | 842 | list_del(&client->list); |
9ddced16 JD |
843 | mutex_unlock(&adapter->clist_lock); |
844 | ||
1da177e4 | 845 | init_completion(&client->released); |
1da177e4 | 846 | device_unregister(&client->dev); |
1da177e4 LT |
847 | wait_for_completion(&client->released); |
848 | ||
849 | out: | |
850 | return res; | |
851 | } | |
c0564606 | 852 | EXPORT_SYMBOL(i2c_detach_client); |
1da177e4 | 853 | |
e48d3319 JD |
854 | /** |
855 | * i2c_use_client - increments the reference count of the i2c client structure | |
856 | * @client: the client being referenced | |
857 | * | |
858 | * Each live reference to a client should be refcounted. The driver model does | |
859 | * that automatically as part of driver binding, so that most drivers don't | |
860 | * need to do this explicitly: they hold a reference until they're unbound | |
861 | * from the device. | |
862 | * | |
863 | * A pointer to the client with the incremented reference counter is returned. | |
864 | */ | |
865 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 866 | { |
6ea438ec DB |
867 | if (client && get_device(&client->dev)) |
868 | return client; | |
869 | return NULL; | |
1da177e4 | 870 | } |
c0564606 | 871 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 872 | |
e48d3319 JD |
873 | /** |
874 | * i2c_release_client - release a use of the i2c client structure | |
875 | * @client: the client being no longer referenced | |
876 | * | |
877 | * Must be called when a user of a client is finished with it. | |
878 | */ | |
879 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 880 | { |
6ea438ec DB |
881 | if (client) |
882 | put_device(&client->dev); | |
1da177e4 | 883 | } |
c0564606 | 884 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 885 | |
9b766b81 DB |
886 | struct i2c_cmd_arg { |
887 | unsigned cmd; | |
888 | void *arg; | |
889 | }; | |
890 | ||
891 | static int i2c_cmd(struct device *dev, void *_arg) | |
892 | { | |
893 | struct i2c_client *client = i2c_verify_client(dev); | |
894 | struct i2c_cmd_arg *arg = _arg; | |
895 | ||
896 | if (client && client->driver && client->driver->command) | |
897 | client->driver->command(client, arg->cmd, arg->arg); | |
898 | return 0; | |
899 | } | |
900 | ||
1da177e4 LT |
901 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
902 | { | |
9b766b81 | 903 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 904 | |
9b766b81 DB |
905 | cmd_arg.cmd = cmd; |
906 | cmd_arg.arg = arg; | |
907 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 908 | } |
c0564606 | 909 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
910 | |
911 | static int __init i2c_init(void) | |
912 | { | |
913 | int retval; | |
914 | ||
915 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
916 | if (retval) |
917 | return retval; | |
e9f1373b DB |
918 | retval = class_register(&i2c_adapter_class); |
919 | if (retval) | |
920 | goto bus_err; | |
921 | retval = i2c_add_driver(&dummy_driver); | |
922 | if (retval) | |
923 | goto class_err; | |
924 | return 0; | |
925 | ||
926 | class_err: | |
927 | class_unregister(&i2c_adapter_class); | |
928 | bus_err: | |
929 | bus_unregister(&i2c_bus_type); | |
930 | return retval; | |
1da177e4 LT |
931 | } |
932 | ||
933 | static void __exit i2c_exit(void) | |
934 | { | |
e9f1373b | 935 | i2c_del_driver(&dummy_driver); |
1da177e4 | 936 | class_unregister(&i2c_adapter_class); |
1da177e4 LT |
937 | bus_unregister(&i2c_bus_type); |
938 | } | |
939 | ||
940 | subsys_initcall(i2c_init); | |
941 | module_exit(i2c_exit); | |
942 | ||
943 | /* ---------------------------------------------------- | |
944 | * the functional interface to the i2c busses. | |
945 | * ---------------------------------------------------- | |
946 | */ | |
947 | ||
a1cdedac DB |
948 | /** |
949 | * i2c_transfer - execute a single or combined I2C message | |
950 | * @adap: Handle to I2C bus | |
951 | * @msgs: One or more messages to execute before STOP is issued to | |
952 | * terminate the operation; each message begins with a START. | |
953 | * @num: Number of messages to be executed. | |
954 | * | |
955 | * Returns negative errno, else the number of messages executed. | |
956 | * | |
957 | * Note that there is no requirement that each message be sent to | |
958 | * the same slave address, although that is the most common model. | |
959 | */ | |
1da177e4 LT |
960 | int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) |
961 | { | |
962 | int ret; | |
963 | ||
a1cdedac DB |
964 | /* REVISIT the fault reporting model here is weak: |
965 | * | |
966 | * - When we get an error after receiving N bytes from a slave, | |
967 | * there is no way to report "N". | |
968 | * | |
969 | * - When we get a NAK after transmitting N bytes to a slave, | |
970 | * there is no way to report "N" ... or to let the master | |
971 | * continue executing the rest of this combined message, if | |
972 | * that's the appropriate response. | |
973 | * | |
974 | * - When for example "num" is two and we successfully complete | |
975 | * the first message but get an error part way through the | |
976 | * second, it's unclear whether that should be reported as | |
977 | * one (discarding status on the second message) or errno | |
978 | * (discarding status on the first one). | |
979 | */ | |
980 | ||
1da177e4 LT |
981 | if (adap->algo->master_xfer) { |
982 | #ifdef DEBUG | |
983 | for (ret = 0; ret < num; ret++) { | |
984 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
985 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
986 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
987 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
988 | } |
989 | #endif | |
990 | ||
cea443a8 MR |
991 | if (in_atomic() || irqs_disabled()) { |
992 | ret = mutex_trylock(&adap->bus_lock); | |
993 | if (!ret) | |
994 | /* I2C activity is ongoing. */ | |
995 | return -EAGAIN; | |
996 | } else { | |
997 | mutex_lock_nested(&adap->bus_lock, adap->level); | |
998 | } | |
999 | ||
1da177e4 | 1000 | ret = adap->algo->master_xfer(adap,msgs,num); |
5c085d36 | 1001 | mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1002 | |
1003 | return ret; | |
1004 | } else { | |
1005 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1006 | return -EOPNOTSUPP; |
1da177e4 LT |
1007 | } |
1008 | } | |
c0564606 | 1009 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1010 | |
a1cdedac DB |
1011 | /** |
1012 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1013 | * @client: Handle to slave device | |
1014 | * @buf: Data that will be written to the slave | |
1015 | * @count: How many bytes to write | |
1016 | * | |
1017 | * Returns negative errno, or else the number of bytes written. | |
1018 | */ | |
1da177e4 LT |
1019 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1020 | { | |
1021 | int ret; | |
1022 | struct i2c_adapter *adap=client->adapter; | |
1023 | struct i2c_msg msg; | |
1024 | ||
815f55f2 JD |
1025 | msg.addr = client->addr; |
1026 | msg.flags = client->flags & I2C_M_TEN; | |
1027 | msg.len = count; | |
1028 | msg.buf = (char *)buf; | |
438d6c2c | 1029 | |
815f55f2 | 1030 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1031 | |
815f55f2 JD |
1032 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1033 | transmitted, else error code. */ | |
1034 | return (ret == 1) ? count : ret; | |
1da177e4 | 1035 | } |
c0564606 | 1036 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1037 | |
a1cdedac DB |
1038 | /** |
1039 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1040 | * @client: Handle to slave device | |
1041 | * @buf: Where to store data read from slave | |
1042 | * @count: How many bytes to read | |
1043 | * | |
1044 | * Returns negative errno, or else the number of bytes read. | |
1045 | */ | |
1da177e4 LT |
1046 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1047 | { | |
1048 | struct i2c_adapter *adap=client->adapter; | |
1049 | struct i2c_msg msg; | |
1050 | int ret; | |
815f55f2 JD |
1051 | |
1052 | msg.addr = client->addr; | |
1053 | msg.flags = client->flags & I2C_M_TEN; | |
1054 | msg.flags |= I2C_M_RD; | |
1055 | msg.len = count; | |
1056 | msg.buf = buf; | |
1057 | ||
1058 | ret = i2c_transfer(adap, &msg, 1); | |
1059 | ||
1060 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1061 | transmitted, else error code. */ | |
1062 | return (ret == 1) ? count : ret; | |
1da177e4 | 1063 | } |
c0564606 | 1064 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1065 | |
1da177e4 LT |
1066 | /* ---------------------------------------------------- |
1067 | * the i2c address scanning function | |
1068 | * Will not work for 10-bit addresses! | |
1069 | * ---------------------------------------------------- | |
1070 | */ | |
a89ba0bc JD |
1071 | static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, |
1072 | int (*found_proc) (struct i2c_adapter *, int, int)) | |
1073 | { | |
1074 | int err; | |
1075 | ||
1076 | /* Make sure the address is valid */ | |
1077 | if (addr < 0x03 || addr > 0x77) { | |
1078 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1079 | addr); | |
1080 | return -EINVAL; | |
9fc6adfa JD |
1081 | } |
1082 | ||
a89ba0bc JD |
1083 | /* Skip if already in use */ |
1084 | if (i2c_check_addr(adapter, addr)) | |
1085 | return 0; | |
1086 | ||
1087 | /* Make sure there is something at this address, unless forced */ | |
4c9337da JD |
1088 | if (kind < 0) { |
1089 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1090 | I2C_SMBUS_QUICK, NULL) < 0) | |
1091 | return 0; | |
1092 | ||
1093 | /* prevent 24RF08 corruption */ | |
1094 | if ((addr & ~0x0f) == 0x50) | |
1095 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1096 | I2C_SMBUS_QUICK, NULL); | |
1097 | } | |
a89ba0bc JD |
1098 | |
1099 | /* Finally call the custom detection function */ | |
1100 | err = found_proc(adapter, addr, kind); | |
a89ba0bc JD |
1101 | /* -ENODEV can be returned if there is a chip at the given address |
1102 | but it isn't supported by this chip driver. We catch it here as | |
1103 | this isn't an error. */ | |
114fd183 JD |
1104 | if (err == -ENODEV) |
1105 | err = 0; | |
1106 | ||
1107 | if (err) | |
1108 | dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n", | |
1109 | addr, err); | |
1110 | return err; | |
9fc6adfa JD |
1111 | } |
1112 | ||
1da177e4 | 1113 | int i2c_probe(struct i2c_adapter *adapter, |
bfb6df24 | 1114 | const struct i2c_client_address_data *address_data, |
1da177e4 LT |
1115 | int (*found_proc) (struct i2c_adapter *, int, int)) |
1116 | { | |
a89ba0bc | 1117 | int i, err; |
1da177e4 LT |
1118 | int adap_id = i2c_adapter_id(adapter); |
1119 | ||
a89ba0bc JD |
1120 | /* Force entries are done first, and are not affected by ignore |
1121 | entries */ | |
1122 | if (address_data->forces) { | |
bfb6df24 | 1123 | const unsigned short * const *forces = address_data->forces; |
a89ba0bc JD |
1124 | int kind; |
1125 | ||
1126 | for (kind = 0; forces[kind]; kind++) { | |
1127 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1128 | i += 2) { | |
1129 | if (forces[kind][i] == adap_id | |
1130 | || forces[kind][i] == ANY_I2C_BUS) { | |
1131 | dev_dbg(&adapter->dev, "found force " | |
1132 | "parameter for adapter %d, " | |
1133 | "addr 0x%02x, kind %d\n", | |
1134 | adap_id, forces[kind][i + 1], | |
1135 | kind); | |
1136 | err = i2c_probe_address(adapter, | |
1137 | forces[kind][i + 1], | |
1138 | kind, found_proc); | |
1139 | if (err) | |
1140 | return err; | |
1141 | } | |
1da177e4 LT |
1142 | } |
1143 | } | |
a89ba0bc | 1144 | } |
1da177e4 | 1145 | |
4366dc94 JD |
1146 | /* Stop here if we can't use SMBUS_QUICK */ |
1147 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1148 | if (address_data->probe[0] == I2C_CLIENT_END | |
1149 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
438d6c2c | 1150 | return 0; |
4366dc94 JD |
1151 | |
1152 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1153 | "can't probe for chips\n"); | |
24a5bb7b | 1154 | return -EOPNOTSUPP; |
4366dc94 JD |
1155 | } |
1156 | ||
a89ba0bc JD |
1157 | /* Probe entries are done second, and are not affected by ignore |
1158 | entries either */ | |
1159 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1160 | if (address_data->probe[i] == adap_id | |
1161 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1162 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1163 | "adapter %d, addr 0x%02x\n", adap_id, | |
1164 | address_data->probe[i + 1]); | |
1165 | err = i2c_probe_address(adapter, | |
1166 | address_data->probe[i + 1], | |
1167 | -1, found_proc); | |
1168 | if (err) | |
1169 | return err; | |
1da177e4 | 1170 | } |
a89ba0bc | 1171 | } |
1da177e4 | 1172 | |
a89ba0bc JD |
1173 | /* Normal entries are done last, unless shadowed by an ignore entry */ |
1174 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1175 | int j, ignore; | |
1176 | ||
1177 | ignore = 0; | |
1178 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1179 | j += 2) { | |
1180 | if ((address_data->ignore[j] == adap_id || | |
1181 | address_data->ignore[j] == ANY_I2C_BUS) | |
1182 | && address_data->ignore[j + 1] | |
1183 | == address_data->normal_i2c[i]) { | |
1184 | dev_dbg(&adapter->dev, "found ignore " | |
1185 | "parameter for adapter %d, " | |
1186 | "addr 0x%02x\n", adap_id, | |
1187 | address_data->ignore[j + 1]); | |
2369df93 MH |
1188 | ignore = 1; |
1189 | break; | |
1da177e4 LT |
1190 | } |
1191 | } | |
a89ba0bc | 1192 | if (ignore) |
1da177e4 LT |
1193 | continue; |
1194 | ||
a89ba0bc JD |
1195 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
1196 | "addr 0x%02x\n", adap_id, | |
1197 | address_data->normal_i2c[i]); | |
1198 | err = i2c_probe_address(adapter, address_data->normal_i2c[i], | |
1199 | -1, found_proc); | |
1200 | if (err) | |
1201 | return err; | |
1da177e4 | 1202 | } |
a89ba0bc | 1203 | |
1da177e4 LT |
1204 | return 0; |
1205 | } | |
c0564606 | 1206 | EXPORT_SYMBOL(i2c_probe); |
1da177e4 | 1207 | |
12b5053a JD |
1208 | struct i2c_client * |
1209 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1210 | struct i2c_board_info *info, | |
1211 | unsigned short const *addr_list) | |
1212 | { | |
1213 | int i; | |
1214 | ||
1215 | /* Stop here if the bus doesn't support probing */ | |
1216 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1217 | dev_err(&adap->dev, "Probing not supported\n"); | |
1218 | return NULL; | |
1219 | } | |
1220 | ||
12b5053a JD |
1221 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1222 | /* Check address validity */ | |
1223 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1224 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1225 | "0x%02x\n", addr_list[i]); | |
1226 | continue; | |
1227 | } | |
1228 | ||
1229 | /* Check address availability */ | |
9b766b81 | 1230 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1231 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1232 | "use, not probing\n", addr_list[i]); | |
1233 | continue; | |
1234 | } | |
1235 | ||
1236 | /* Test address responsiveness | |
1237 | The default probe method is a quick write, but it is known | |
1238 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1239 | and could also irreversibly write-protect some EEPROMs, so | |
1240 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1241 | read instead. Also, some bus drivers don't implement | |
1242 | quick write, so we fallback to a byte read it that case | |
1243 | too. */ | |
1244 | if ((addr_list[i] & ~0x07) == 0x30 | |
1245 | || (addr_list[i] & ~0x0f) == 0x50 | |
1246 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
1247 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1248 | I2C_SMBUS_READ, 0, | |
1249 | I2C_SMBUS_BYTE, NULL) >= 0) | |
1250 | break; | |
1251 | } else { | |
1252 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1253 | I2C_SMBUS_WRITE, 0, | |
1254 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1255 | break; | |
1256 | } | |
1257 | } | |
12b5053a JD |
1258 | |
1259 | if (addr_list[i] == I2C_CLIENT_END) { | |
1260 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1261 | return NULL; | |
1262 | } | |
1263 | ||
1264 | info->addr = addr_list[i]; | |
1265 | return i2c_new_device(adap, info); | |
1266 | } | |
1267 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1268 | ||
1da177e4 LT |
1269 | struct i2c_adapter* i2c_get_adapter(int id) |
1270 | { | |
1da177e4 | 1271 | struct i2c_adapter *adapter; |
438d6c2c | 1272 | |
caada32a | 1273 | mutex_lock(&core_lock); |
a0920e10 MH |
1274 | adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); |
1275 | if (adapter && !try_module_get(adapter->owner)) | |
1276 | adapter = NULL; | |
1277 | ||
caada32a | 1278 | mutex_unlock(&core_lock); |
a0920e10 | 1279 | return adapter; |
1da177e4 | 1280 | } |
c0564606 | 1281 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1282 | |
1283 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1284 | { | |
1285 | module_put(adap->owner); | |
1286 | } | |
c0564606 | 1287 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1288 | |
1289 | /* The SMBus parts */ | |
1290 | ||
438d6c2c | 1291 | #define POLY (0x1070U << 3) |
1da177e4 LT |
1292 | static u8 |
1293 | crc8(u16 data) | |
1294 | { | |
1295 | int i; | |
438d6c2c | 1296 | |
1da177e4 | 1297 | for(i = 0; i < 8; i++) { |
438d6c2c | 1298 | if (data & 0x8000) |
1da177e4 LT |
1299 | data = data ^ POLY; |
1300 | data = data << 1; | |
1301 | } | |
1302 | return (u8)(data >> 8); | |
1303 | } | |
1304 | ||
421ef47b JD |
1305 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1306 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1307 | { |
1308 | int i; | |
1309 | ||
1310 | for(i = 0; i < count; i++) | |
421ef47b | 1311 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1312 | return crc; |
1313 | } | |
1314 | ||
421ef47b JD |
1315 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1316 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1317 | { |
421ef47b JD |
1318 | /* The address will be sent first */ |
1319 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1320 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1321 | ||
1322 | /* The data buffer follows */ | |
1323 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1324 | } |
1325 | ||
421ef47b JD |
1326 | /* Used for write only transactions */ |
1327 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1328 | { |
421ef47b JD |
1329 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1330 | msg->len++; | |
1da177e4 LT |
1331 | } |
1332 | ||
421ef47b JD |
1333 | /* Return <0 on CRC error |
1334 | If there was a write before this read (most cases) we need to take the | |
1335 | partial CRC from the write part into account. | |
1336 | Note that this function does modify the message (we need to decrease the | |
1337 | message length to hide the CRC byte from the caller). */ | |
1338 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1339 | { |
421ef47b JD |
1340 | u8 rpec = msg->buf[--msg->len]; |
1341 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1342 | |
1da177e4 LT |
1343 | if (rpec != cpec) { |
1344 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1345 | rpec, cpec); | |
24a5bb7b | 1346 | return -EBADMSG; |
1da177e4 | 1347 | } |
438d6c2c | 1348 | return 0; |
1da177e4 LT |
1349 | } |
1350 | ||
a1cdedac DB |
1351 | /** |
1352 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1353 | * @client: Handle to slave device | |
1354 | * | |
1355 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1356 | * else the byte received from the device. | |
1357 | */ | |
1da177e4 LT |
1358 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1359 | { | |
1360 | union i2c_smbus_data data; | |
24a5bb7b DB |
1361 | int status; |
1362 | ||
1363 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1364 | I2C_SMBUS_READ, 0, | |
1365 | I2C_SMBUS_BYTE, &data); | |
1366 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1367 | } |
c0564606 | 1368 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1369 | |
a1cdedac DB |
1370 | /** |
1371 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1372 | * @client: Handle to slave device | |
1373 | * @value: Byte to be sent | |
1374 | * | |
1375 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1376 | * else zero on success. | |
1377 | */ | |
1da177e4 LT |
1378 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1379 | { | |
1da177e4 | 1380 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1381 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1382 | } |
c0564606 | 1383 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1384 | |
a1cdedac DB |
1385 | /** |
1386 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1387 | * @client: Handle to slave device | |
1388 | * @command: Byte interpreted by slave | |
1389 | * | |
1390 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1391 | * else a data byte received from the device. | |
1392 | */ | |
1da177e4 LT |
1393 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1394 | { | |
1395 | union i2c_smbus_data data; | |
24a5bb7b DB |
1396 | int status; |
1397 | ||
1398 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1399 | I2C_SMBUS_READ, command, | |
1400 | I2C_SMBUS_BYTE_DATA, &data); | |
1401 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1402 | } |
c0564606 | 1403 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1404 | |
a1cdedac DB |
1405 | /** |
1406 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1407 | * @client: Handle to slave device | |
1408 | * @command: Byte interpreted by slave | |
1409 | * @value: Byte being written | |
1410 | * | |
1411 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1412 | * else zero on success. | |
1413 | */ | |
1da177e4 LT |
1414 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1415 | { | |
1416 | union i2c_smbus_data data; | |
1417 | data.byte = value; | |
1418 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1419 | I2C_SMBUS_WRITE,command, | |
1420 | I2C_SMBUS_BYTE_DATA,&data); | |
1421 | } | |
c0564606 | 1422 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1423 | |
a1cdedac DB |
1424 | /** |
1425 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1426 | * @client: Handle to slave device | |
1427 | * @command: Byte interpreted by slave | |
1428 | * | |
1429 | * This executes the SMBus "read word" protocol, returning negative errno | |
1430 | * else a 16-bit unsigned "word" received from the device. | |
1431 | */ | |
1da177e4 LT |
1432 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1433 | { | |
1434 | union i2c_smbus_data data; | |
24a5bb7b DB |
1435 | int status; |
1436 | ||
1437 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1438 | I2C_SMBUS_READ, command, | |
1439 | I2C_SMBUS_WORD_DATA, &data); | |
1440 | return (status < 0) ? status : data.word; | |
1da177e4 | 1441 | } |
c0564606 | 1442 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1443 | |
a1cdedac DB |
1444 | /** |
1445 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1446 | * @client: Handle to slave device | |
1447 | * @command: Byte interpreted by slave | |
1448 | * @value: 16-bit "word" being written | |
1449 | * | |
1450 | * This executes the SMBus "write word" protocol, returning negative errno | |
1451 | * else zero on success. | |
1452 | */ | |
1da177e4 LT |
1453 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1454 | { | |
1455 | union i2c_smbus_data data; | |
1456 | data.word = value; | |
1457 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1458 | I2C_SMBUS_WRITE,command, | |
1459 | I2C_SMBUS_WORD_DATA,&data); | |
1460 | } | |
c0564606 | 1461 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1462 | |
a64ec07d | 1463 | /** |
a1cdedac | 1464 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1465 | * @client: Handle to slave device |
a1cdedac | 1466 | * @command: Byte interpreted by slave |
a64ec07d DB |
1467 | * @values: Byte array into which data will be read; big enough to hold |
1468 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1469 | * | |
a1cdedac DB |
1470 | * This executes the SMBus "block read" protocol, returning negative errno |
1471 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1472 | * |
1473 | * Note that using this function requires that the client's adapter support | |
1474 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1475 | * support this; its emulation through I2C messaging relies on a specific | |
1476 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1477 | */ | |
b86a1bc8 JD |
1478 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1479 | u8 *values) | |
1480 | { | |
1481 | union i2c_smbus_data data; | |
24a5bb7b | 1482 | int status; |
b86a1bc8 | 1483 | |
24a5bb7b DB |
1484 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1485 | I2C_SMBUS_READ, command, | |
1486 | I2C_SMBUS_BLOCK_DATA, &data); | |
1487 | if (status) | |
1488 | return status; | |
b86a1bc8 JD |
1489 | |
1490 | memcpy(values, &data.block[1], data.block[0]); | |
1491 | return data.block[0]; | |
1492 | } | |
1493 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1494 | ||
a1cdedac DB |
1495 | /** |
1496 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1497 | * @client: Handle to slave device | |
1498 | * @command: Byte interpreted by slave | |
1499 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1500 | * @values: Byte array which will be written. | |
1501 | * | |
1502 | * This executes the SMBus "block write" protocol, returning negative errno | |
1503 | * else zero on success. | |
1504 | */ | |
1da177e4 | 1505 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1506 | u8 length, const u8 *values) |
1da177e4 LT |
1507 | { |
1508 | union i2c_smbus_data data; | |
7656032b | 1509 | |
1da177e4 LT |
1510 | if (length > I2C_SMBUS_BLOCK_MAX) |
1511 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1512 | data.block[0] = length; |
7656032b | 1513 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1514 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1515 | I2C_SMBUS_WRITE,command, | |
1516 | I2C_SMBUS_BLOCK_DATA,&data); | |
1517 | } | |
c0564606 | 1518 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1519 | |
1520 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1521 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1522 | u8 length, u8 *values) | |
1da177e4 LT |
1523 | { |
1524 | union i2c_smbus_data data; | |
24a5bb7b | 1525 | int status; |
7656032b | 1526 | |
4b2643d7 JD |
1527 | if (length > I2C_SMBUS_BLOCK_MAX) |
1528 | length = I2C_SMBUS_BLOCK_MAX; | |
1529 | data.block[0] = length; | |
24a5bb7b DB |
1530 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1531 | I2C_SMBUS_READ, command, | |
1532 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1533 | if (status < 0) | |
1534 | return status; | |
7656032b JD |
1535 | |
1536 | memcpy(values, &data.block[1], data.block[0]); | |
1537 | return data.block[0]; | |
1da177e4 | 1538 | } |
c0564606 | 1539 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1540 | |
21bbd691 | 1541 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1542 | u8 length, const u8 *values) |
21bbd691 JD |
1543 | { |
1544 | union i2c_smbus_data data; | |
1545 | ||
1546 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1547 | length = I2C_SMBUS_BLOCK_MAX; | |
1548 | data.block[0] = length; | |
1549 | memcpy(data.block + 1, values, length); | |
1550 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1551 | I2C_SMBUS_WRITE, command, | |
1552 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1553 | } | |
c0564606 | 1554 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1555 | |
438d6c2c | 1556 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1557 | No checking of parameters is done! */ |
438d6c2c | 1558 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1559 | unsigned short flags, |
438d6c2c | 1560 | char read_write, u8 command, int size, |
1da177e4 LT |
1561 | union i2c_smbus_data * data) |
1562 | { | |
1563 | /* So we need to generate a series of msgs. In the case of writing, we | |
1564 | need to use only one message; when reading, we need two. We initialize | |
1565 | most things with sane defaults, to keep the code below somewhat | |
1566 | simpler. */ | |
5c50d188 HI |
1567 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1568 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1569 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1570 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1571 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1572 | }; | |
1573 | int i; | |
421ef47b | 1574 | u8 partial_pec = 0; |
24a5bb7b | 1575 | int status; |
1da177e4 LT |
1576 | |
1577 | msgbuf0[0] = command; | |
1578 | switch(size) { | |
1579 | case I2C_SMBUS_QUICK: | |
1580 | msg[0].len = 0; | |
1581 | /* Special case: The read/write field is used as data */ | |
1582 | msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0; | |
1583 | num = 1; | |
1584 | break; | |
1585 | case I2C_SMBUS_BYTE: | |
1586 | if (read_write == I2C_SMBUS_READ) { | |
1587 | /* Special case: only a read! */ | |
1588 | msg[0].flags = I2C_M_RD | flags; | |
1589 | num = 1; | |
1590 | } | |
1591 | break; | |
1592 | case I2C_SMBUS_BYTE_DATA: | |
1593 | if (read_write == I2C_SMBUS_READ) | |
1594 | msg[1].len = 1; | |
1595 | else { | |
1596 | msg[0].len = 2; | |
1597 | msgbuf0[1] = data->byte; | |
1598 | } | |
1599 | break; | |
1600 | case I2C_SMBUS_WORD_DATA: | |
1601 | if (read_write == I2C_SMBUS_READ) | |
1602 | msg[1].len = 2; | |
1603 | else { | |
1604 | msg[0].len=3; | |
1605 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1606 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1607 | } |
1608 | break; | |
1609 | case I2C_SMBUS_PROC_CALL: | |
1610 | num = 2; /* Special case */ | |
1611 | read_write = I2C_SMBUS_READ; | |
1612 | msg[0].len = 3; | |
1613 | msg[1].len = 2; | |
1614 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1615 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1616 | break; |
1617 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1618 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1619 | msg[1].flags |= I2C_M_RECV_LEN; |
1620 | msg[1].len = 1; /* block length will be added by | |
1621 | the underlying bus driver */ | |
1da177e4 LT |
1622 | } else { |
1623 | msg[0].len = data->block[0] + 2; | |
1624 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1625 | dev_err(&adapter->dev, |
1626 | "Invalid block write size %d\n", | |
1627 | data->block[0]); | |
1628 | return -EINVAL; | |
1da177e4 | 1629 | } |
5c50d188 | 1630 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1631 | msgbuf0[i] = data->block[i-1]; |
1632 | } | |
1633 | break; | |
1634 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1635 | num = 2; /* Another special case */ |
1636 | read_write = I2C_SMBUS_READ; | |
1637 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1638 | dev_err(&adapter->dev, |
1639 | "Invalid block write size %d\n", | |
209d27c3 | 1640 | data->block[0]); |
24a5bb7b | 1641 | return -EINVAL; |
209d27c3 JD |
1642 | } |
1643 | msg[0].len = data->block[0] + 2; | |
1644 | for (i = 1; i < msg[0].len; i++) | |
1645 | msgbuf0[i] = data->block[i-1]; | |
1646 | msg[1].flags |= I2C_M_RECV_LEN; | |
1647 | msg[1].len = 1; /* block length will be added by | |
1648 | the underlying bus driver */ | |
1649 | break; | |
1da177e4 LT |
1650 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1651 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1652 | msg[1].len = data->block[0]; |
1da177e4 LT |
1653 | } else { |
1654 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1655 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1656 | dev_err(&adapter->dev, |
1657 | "Invalid block write size %d\n", | |
1658 | data->block[0]); | |
1659 | return -EINVAL; | |
1da177e4 LT |
1660 | } |
1661 | for (i = 1; i <= data->block[0]; i++) | |
1662 | msgbuf0[i] = data->block[i]; | |
1663 | } | |
1664 | break; | |
1665 | default: | |
24a5bb7b DB |
1666 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1667 | return -EOPNOTSUPP; | |
1da177e4 LT |
1668 | } |
1669 | ||
421ef47b JD |
1670 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1671 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1672 | if (i) { | |
1673 | /* Compute PEC if first message is a write */ | |
1674 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1675 | if (num == 1) /* Write only */ |
421ef47b JD |
1676 | i2c_smbus_add_pec(&msg[0]); |
1677 | else /* Write followed by read */ | |
1678 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1679 | } | |
1680 | /* Ask for PEC if last message is a read */ | |
1681 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1682 | msg[num-1].len++; |
421ef47b JD |
1683 | } |
1684 | ||
24a5bb7b DB |
1685 | status = i2c_transfer(adapter, msg, num); |
1686 | if (status < 0) | |
1687 | return status; | |
1da177e4 | 1688 | |
421ef47b JD |
1689 | /* Check PEC if last message is a read */ |
1690 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1691 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1692 | if (status < 0) | |
1693 | return status; | |
421ef47b JD |
1694 | } |
1695 | ||
1da177e4 LT |
1696 | if (read_write == I2C_SMBUS_READ) |
1697 | switch(size) { | |
1698 | case I2C_SMBUS_BYTE: | |
1699 | data->byte = msgbuf0[0]; | |
1700 | break; | |
1701 | case I2C_SMBUS_BYTE_DATA: | |
1702 | data->byte = msgbuf1[0]; | |
1703 | break; | |
438d6c2c | 1704 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1705 | case I2C_SMBUS_PROC_CALL: |
1706 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1707 | break; | |
1708 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1709 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1710 | data->block[i+1] = msgbuf1[i]; |
1711 | break; | |
209d27c3 JD |
1712 | case I2C_SMBUS_BLOCK_DATA: |
1713 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1714 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1715 | data->block[i] = msgbuf1[i]; | |
1716 | break; | |
1da177e4 LT |
1717 | } |
1718 | return 0; | |
1719 | } | |
1720 | ||
a1cdedac DB |
1721 | /** |
1722 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1723 | * @adapter: Handle to I2C bus | |
1724 | * @addr: Address of SMBus slave on that bus | |
1725 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1726 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1727 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1728 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1729 | * @data: Data to be read or written | |
1730 | * | |
1731 | * This executes an SMBus protocol operation, and returns a negative | |
1732 | * errno code else zero on success. | |
1733 | */ | |
1da177e4 | 1734 | s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, |
a1cdedac | 1735 | char read_write, u8 command, int protocol, |
1da177e4 LT |
1736 | union i2c_smbus_data * data) |
1737 | { | |
1738 | s32 res; | |
1da177e4 LT |
1739 | |
1740 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1741 | |
1742 | if (adapter->algo->smbus_xfer) { | |
5c085d36 | 1743 | mutex_lock(&adapter->bus_lock); |
1da177e4 | 1744 | res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, |
a1cdedac | 1745 | command, protocol, data); |
5c085d36 | 1746 | mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1747 | } else |
1748 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1749 | command, protocol, data); |
1da177e4 | 1750 | |
1da177e4 LT |
1751 | return res; |
1752 | } | |
1da177e4 | 1753 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1754 | |
1755 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1756 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1757 | MODULE_LICENSE("GPL"); |