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 | ||
4735c98f JD |
45 | #define is_newstyle_driver(d) ((d)->probe || (d)->remove || (d)->detect) |
46 | ||
47 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); | |
f37dd80a DB |
48 | |
49 | /* ------------------------------------------------------------------------- */ | |
50 | ||
d2653e92 JD |
51 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
52 | const struct i2c_client *client) | |
53 | { | |
54 | while (id->name[0]) { | |
55 | if (strcmp(client->name, id->name) == 0) | |
56 | return id; | |
57 | id++; | |
58 | } | |
59 | return NULL; | |
60 | } | |
61 | ||
1da177e4 LT |
62 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
63 | { | |
7b4fbc50 DB |
64 | struct i2c_client *client = to_i2c_client(dev); |
65 | struct i2c_driver *driver = to_i2c_driver(drv); | |
66 | ||
67 | /* make legacy i2c drivers bypass driver model probing entirely; | |
68 | * such drivers scan each i2c adapter/bus themselves. | |
69 | */ | |
a1d9e6e4 | 70 | if (!is_newstyle_driver(driver)) |
7b4fbc50 DB |
71 | return 0; |
72 | ||
d2653e92 JD |
73 | /* match on an id table if there is one */ |
74 | if (driver->id_table) | |
75 | return i2c_match_id(driver->id_table, client) != NULL; | |
76 | ||
eb8a7908 | 77 | return 0; |
1da177e4 LT |
78 | } |
79 | ||
7b4fbc50 DB |
80 | #ifdef CONFIG_HOTPLUG |
81 | ||
82 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 83 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
84 | { |
85 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 DB |
86 | |
87 | /* by definition, legacy drivers can't hotplug */ | |
d2653e92 | 88 | if (dev->driver) |
7b4fbc50 DB |
89 | return 0; |
90 | ||
eb8a7908 JD |
91 | if (add_uevent_var(env, "MODALIAS=%s%s", |
92 | I2C_MODULE_PREFIX, client->name)) | |
93 | return -ENOMEM; | |
7b4fbc50 DB |
94 | dev_dbg(dev, "uevent\n"); |
95 | return 0; | |
96 | } | |
97 | ||
98 | #else | |
99 | #define i2c_device_uevent NULL | |
100 | #endif /* CONFIG_HOTPLUG */ | |
101 | ||
f37dd80a | 102 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 103 | { |
7b4fbc50 DB |
104 | struct i2c_client *client = to_i2c_client(dev); |
105 | struct i2c_driver *driver = to_i2c_driver(dev->driver); | |
50c3304a | 106 | int status; |
7b4fbc50 | 107 | |
e0457442 | 108 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
109 | return -ENODEV; |
110 | client->driver = driver; | |
ee35425c MP |
111 | if (!device_can_wakeup(&client->dev)) |
112 | device_init_wakeup(&client->dev, | |
113 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 114 | dev_dbg(dev, "probe\n"); |
d2653e92 | 115 | |
e0457442 | 116 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
117 | if (status) |
118 | client->driver = NULL; | |
119 | return status; | |
f37dd80a | 120 | } |
1da177e4 | 121 | |
f37dd80a DB |
122 | static int i2c_device_remove(struct device *dev) |
123 | { | |
a1d9e6e4 DB |
124 | struct i2c_client *client = to_i2c_client(dev); |
125 | struct i2c_driver *driver; | |
126 | int status; | |
127 | ||
128 | if (!dev->driver) | |
129 | return 0; | |
130 | ||
131 | driver = to_i2c_driver(dev->driver); | |
132 | if (driver->remove) { | |
133 | dev_dbg(dev, "remove\n"); | |
134 | status = driver->remove(client); | |
135 | } else { | |
136 | dev->driver = NULL; | |
137 | status = 0; | |
138 | } | |
139 | if (status == 0) | |
140 | client->driver = NULL; | |
141 | return status; | |
1da177e4 LT |
142 | } |
143 | ||
f37dd80a | 144 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 145 | { |
f37dd80a DB |
146 | struct i2c_driver *driver; |
147 | ||
148 | if (!dev->driver) | |
149 | return; | |
150 | driver = to_i2c_driver(dev->driver); | |
151 | if (driver->shutdown) | |
152 | driver->shutdown(to_i2c_client(dev)); | |
1da177e4 LT |
153 | } |
154 | ||
f37dd80a | 155 | static int i2c_device_suspend(struct device * dev, pm_message_t mesg) |
1da177e4 | 156 | { |
f37dd80a DB |
157 | struct i2c_driver *driver; |
158 | ||
159 | if (!dev->driver) | |
160 | return 0; | |
161 | driver = to_i2c_driver(dev->driver); | |
162 | if (!driver->suspend) | |
163 | return 0; | |
164 | return driver->suspend(to_i2c_client(dev), mesg); | |
1da177e4 LT |
165 | } |
166 | ||
f37dd80a | 167 | static int i2c_device_resume(struct device * dev) |
1da177e4 | 168 | { |
f37dd80a DB |
169 | struct i2c_driver *driver; |
170 | ||
171 | if (!dev->driver) | |
172 | return 0; | |
173 | driver = to_i2c_driver(dev->driver); | |
174 | if (!driver->resume) | |
175 | return 0; | |
176 | return driver->resume(to_i2c_client(dev)); | |
1da177e4 LT |
177 | } |
178 | ||
7b4fbc50 DB |
179 | static void i2c_client_release(struct device *dev) |
180 | { | |
181 | struct i2c_client *client = to_i2c_client(dev); | |
182 | complete(&client->released); | |
183 | } | |
184 | ||
9c1600ed DB |
185 | static void i2c_client_dev_release(struct device *dev) |
186 | { | |
187 | kfree(to_i2c_client(dev)); | |
188 | } | |
189 | ||
7b4fbc50 DB |
190 | static ssize_t show_client_name(struct device *dev, struct device_attribute *attr, char *buf) |
191 | { | |
192 | struct i2c_client *client = to_i2c_client(dev); | |
193 | return sprintf(buf, "%s\n", client->name); | |
194 | } | |
195 | ||
196 | static ssize_t show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
197 | { | |
198 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 199 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
200 | } |
201 | ||
202 | static struct device_attribute i2c_dev_attrs[] = { | |
203 | __ATTR(name, S_IRUGO, show_client_name, NULL), | |
204 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ | |
205 | __ATTR(modalias, S_IRUGO, show_modalias, NULL), | |
206 | { }, | |
207 | }; | |
208 | ||
e9ca9eb9 | 209 | struct bus_type i2c_bus_type = { |
f37dd80a | 210 | .name = "i2c", |
7b4fbc50 | 211 | .dev_attrs = i2c_dev_attrs, |
f37dd80a | 212 | .match = i2c_device_match, |
7b4fbc50 | 213 | .uevent = i2c_device_uevent, |
f37dd80a DB |
214 | .probe = i2c_device_probe, |
215 | .remove = i2c_device_remove, | |
216 | .shutdown = i2c_device_shutdown, | |
217 | .suspend = i2c_device_suspend, | |
218 | .resume = i2c_device_resume, | |
b864c7d5 | 219 | }; |
e9ca9eb9 | 220 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 221 | |
9b766b81 DB |
222 | |
223 | /** | |
224 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
225 | * @dev: device, probably from some driver model iterator | |
226 | * | |
227 | * When traversing the driver model tree, perhaps using driver model | |
228 | * iterators like @device_for_each_child(), you can't assume very much | |
229 | * about the nodes you find. Use this function to avoid oopses caused | |
230 | * by wrongly treating some non-I2C device as an i2c_client. | |
231 | */ | |
232 | struct i2c_client *i2c_verify_client(struct device *dev) | |
233 | { | |
234 | return (dev->bus == &i2c_bus_type) | |
235 | ? to_i2c_client(dev) | |
236 | : NULL; | |
237 | } | |
238 | EXPORT_SYMBOL(i2c_verify_client); | |
239 | ||
240 | ||
9c1600ed DB |
241 | /** |
242 | * i2c_new_device - instantiate an i2c device for use with a new style driver | |
243 | * @adap: the adapter managing the device | |
244 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 245 | * Context: can sleep |
9c1600ed DB |
246 | * |
247 | * Create a device to work with a new style i2c driver, where binding is | |
248 | * handled through driver model probe()/remove() methods. This call is not | |
249 | * appropriate for use by mainboad initialization logic, which usually runs | |
250 | * during an arch_initcall() long before any i2c_adapter could exist. | |
251 | * | |
252 | * This returns the new i2c client, which may be saved for later use with | |
253 | * i2c_unregister_device(); or NULL to indicate an error. | |
254 | */ | |
255 | struct i2c_client * | |
256 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
257 | { | |
258 | struct i2c_client *client; | |
259 | int status; | |
260 | ||
261 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
262 | if (!client) | |
263 | return NULL; | |
264 | ||
265 | client->adapter = adap; | |
266 | ||
267 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 268 | |
ee35425c | 269 | client->flags = info->flags; |
9c1600ed DB |
270 | client->addr = info->addr; |
271 | client->irq = info->irq; | |
272 | ||
9c1600ed DB |
273 | strlcpy(client->name, info->type, sizeof(client->name)); |
274 | ||
275 | /* a new style driver may be bound to this device when we | |
276 | * return from this function, or any later moment (e.g. maybe | |
277 | * hotplugging will load the driver module). and the device | |
278 | * refcount model is the standard driver model one. | |
279 | */ | |
280 | status = i2c_attach_client(client); | |
281 | if (status < 0) { | |
282 | kfree(client); | |
283 | client = NULL; | |
284 | } | |
285 | return client; | |
286 | } | |
287 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
288 | ||
289 | ||
290 | /** | |
291 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
292 | * @client: value returned from i2c_new_device() | |
d64f73be | 293 | * Context: can sleep |
9c1600ed DB |
294 | */ |
295 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 DB |
296 | { |
297 | struct i2c_adapter *adapter = client->adapter; | |
298 | struct i2c_driver *driver = client->driver; | |
299 | ||
300 | if (driver && !is_newstyle_driver(driver)) { | |
301 | dev_err(&client->dev, "can't unregister devices " | |
302 | "with legacy drivers\n"); | |
303 | WARN_ON(1); | |
304 | return; | |
305 | } | |
306 | ||
8508159e JD |
307 | if (adapter->client_unregister) { |
308 | if (adapter->client_unregister(client)) { | |
309 | dev_warn(&client->dev, | |
310 | "client_unregister [%s] failed\n", | |
311 | client->name); | |
312 | } | |
313 | } | |
314 | ||
a1d9e6e4 DB |
315 | mutex_lock(&adapter->clist_lock); |
316 | list_del(&client->list); | |
317 | mutex_unlock(&adapter->clist_lock); | |
318 | ||
319 | device_unregister(&client->dev); | |
320 | } | |
9c1600ed | 321 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
322 | |
323 | ||
60b129d7 JD |
324 | static const struct i2c_device_id dummy_id[] = { |
325 | { "dummy", 0 }, | |
326 | { }, | |
327 | }; | |
328 | ||
d2653e92 JD |
329 | static int dummy_probe(struct i2c_client *client, |
330 | const struct i2c_device_id *id) | |
331 | { | |
332 | return 0; | |
333 | } | |
334 | ||
335 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
336 | { |
337 | return 0; | |
338 | } | |
339 | ||
340 | static struct i2c_driver dummy_driver = { | |
341 | .driver.name = "dummy", | |
d2653e92 JD |
342 | .probe = dummy_probe, |
343 | .remove = dummy_remove, | |
60b129d7 | 344 | .id_table = dummy_id, |
e9f1373b DB |
345 | }; |
346 | ||
347 | /** | |
348 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
349 | * @adapter: the adapter managing the device | |
350 | * @address: seven bit address to be used | |
e9f1373b DB |
351 | * Context: can sleep |
352 | * | |
353 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
354 | * with devices that consume multiple addresses. Examples of such chips | |
355 | * include various EEPROMS (like 24c04 and 24c08 models). | |
356 | * | |
357 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
358 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
359 | * And second, this prevents the specified address from being bound to a | |
360 | * different driver. | |
361 | * | |
362 | * This returns the new i2c client, which should be saved for later use with | |
363 | * i2c_unregister_device(); or NULL to indicate an error. | |
364 | */ | |
365 | struct i2c_client * | |
60b129d7 | 366 | i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
367 | { |
368 | struct i2c_board_info info = { | |
60b129d7 | 369 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
370 | }; |
371 | ||
e9f1373b DB |
372 | return i2c_new_device(adapter, &info); |
373 | } | |
374 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
375 | ||
f37dd80a DB |
376 | /* ------------------------------------------------------------------------- */ |
377 | ||
16ffadfc DB |
378 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
379 | ||
83eaaed0 | 380 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 381 | { |
ef2c8321 | 382 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
383 | complete(&adap->dev_released); |
384 | } | |
385 | ||
16ffadfc DB |
386 | static ssize_t |
387 | show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) | |
388 | { | |
ef2c8321 | 389 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
16ffadfc DB |
390 | return sprintf(buf, "%s\n", adap->name); |
391 | } | |
b119dc3f | 392 | |
16ffadfc DB |
393 | static struct device_attribute i2c_adapter_attrs[] = { |
394 | __ATTR(name, S_IRUGO, show_adapter_name, NULL), | |
395 | { }, | |
396 | }; | |
b119dc3f | 397 | |
83eaaed0 | 398 | static struct class i2c_adapter_class = { |
b119dc3f DB |
399 | .owner = THIS_MODULE, |
400 | .name = "i2c-adapter", | |
16ffadfc | 401 | .dev_attrs = i2c_adapter_attrs, |
1da177e4 LT |
402 | }; |
403 | ||
9c1600ed DB |
404 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
405 | { | |
406 | struct i2c_devinfo *devinfo; | |
407 | ||
408 | mutex_lock(&__i2c_board_lock); | |
409 | list_for_each_entry(devinfo, &__i2c_board_list, list) { | |
410 | if (devinfo->busnum == adapter->nr | |
411 | && !i2c_new_device(adapter, | |
412 | &devinfo->board_info)) | |
413 | printk(KERN_ERR "i2c-core: can't create i2c%d-%04x\n", | |
414 | i2c_adapter_id(adapter), | |
415 | devinfo->board_info.addr); | |
416 | } | |
417 | mutex_unlock(&__i2c_board_lock); | |
418 | } | |
419 | ||
026526f5 JD |
420 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
421 | { | |
422 | struct i2c_driver *driver = to_i2c_driver(d); | |
423 | struct i2c_adapter *adap = data; | |
424 | ||
4735c98f JD |
425 | /* Detect supported devices on that bus, and instantiate them */ |
426 | i2c_detect(adap, driver); | |
427 | ||
428 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
429 | if (driver->attach_adapter) { |
430 | /* We ignore the return code; if it fails, too bad */ | |
431 | driver->attach_adapter(adap); | |
432 | } | |
433 | return 0; | |
434 | } | |
435 | ||
6e13e641 | 436 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 437 | { |
026526f5 | 438 | int res = 0, dummy; |
1da177e4 | 439 | |
5c085d36 IM |
440 | mutex_init(&adap->bus_lock); |
441 | mutex_init(&adap->clist_lock); | |
1da177e4 LT |
442 | INIT_LIST_HEAD(&adap->clients); |
443 | ||
caada32a | 444 | mutex_lock(&core_lock); |
6e13e641 | 445 | |
1da177e4 LT |
446 | /* Add the adapter to the driver core. |
447 | * If the parent pointer is not set up, | |
448 | * we add this adapter to the host bus. | |
449 | */ | |
b119dc3f | 450 | if (adap->dev.parent == NULL) { |
1da177e4 | 451 | adap->dev.parent = &platform_bus; |
fe2c8d51 JD |
452 | pr_debug("I2C adapter driver [%s] forgot to specify " |
453 | "physical device\n", adap->name); | |
b119dc3f | 454 | } |
1da177e4 | 455 | sprintf(adap->dev.bus_id, "i2c-%d", adap->nr); |
1da177e4 | 456 | adap->dev.release = &i2c_adapter_dev_release; |
fccb56e4 | 457 | adap->dev.class = &i2c_adapter_class; |
b119c6c9 JD |
458 | res = device_register(&adap->dev); |
459 | if (res) | |
460 | goto out_list; | |
1da177e4 | 461 | |
b6d7b3d1 JD |
462 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
463 | ||
6e13e641 DB |
464 | /* create pre-declared device nodes for new-style drivers */ |
465 | if (adap->nr < __i2c_first_dynamic_bus_num) | |
466 | i2c_scan_static_board_info(adap); | |
467 | ||
4735c98f | 468 | /* Notify drivers */ |
026526f5 JD |
469 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
470 | i2c_do_add_adapter); | |
1da177e4 | 471 | |
1da177e4 | 472 | out_unlock: |
caada32a | 473 | mutex_unlock(&core_lock); |
1da177e4 | 474 | return res; |
b119c6c9 | 475 | |
b119c6c9 | 476 | out_list: |
b119c6c9 JD |
477 | idr_remove(&i2c_adapter_idr, adap->nr); |
478 | goto out_unlock; | |
1da177e4 LT |
479 | } |
480 | ||
6e13e641 DB |
481 | /** |
482 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
483 | * @adapter: the adapter to add | |
d64f73be | 484 | * Context: can sleep |
6e13e641 DB |
485 | * |
486 | * This routine is used to declare an I2C adapter when its bus number | |
487 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
488 | * USB links or PCI plugin cards. | |
489 | * | |
490 | * When this returns zero, a new bus number was allocated and stored | |
491 | * in adap->nr, and the specified adapter became available for clients. | |
492 | * Otherwise, a negative errno value is returned. | |
493 | */ | |
494 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
495 | { | |
496 | int id, res = 0; | |
497 | ||
498 | retry: | |
499 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
500 | return -ENOMEM; | |
501 | ||
caada32a | 502 | mutex_lock(&core_lock); |
6e13e641 DB |
503 | /* "above" here means "above or equal to", sigh */ |
504 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
505 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 506 | mutex_unlock(&core_lock); |
6e13e641 DB |
507 | |
508 | if (res < 0) { | |
509 | if (res == -EAGAIN) | |
510 | goto retry; | |
511 | return res; | |
512 | } | |
513 | ||
514 | adapter->nr = id; | |
515 | return i2c_register_adapter(adapter); | |
516 | } | |
517 | EXPORT_SYMBOL(i2c_add_adapter); | |
518 | ||
519 | /** | |
520 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
521 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 522 | * Context: can sleep |
6e13e641 DB |
523 | * |
524 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
525 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
526 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
527 | * is used to properly configure I2C devices. |
528 | * | |
529 | * If no devices have pre-been declared for this bus, then be sure to | |
530 | * register the adapter before any dynamically allocated ones. Otherwise | |
531 | * the required bus ID may not be available. | |
532 | * | |
533 | * When this returns zero, the specified adapter became available for | |
534 | * clients using the bus number provided in adap->nr. Also, the table | |
535 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
536 | * and the appropriate driver model device nodes are created. Otherwise, a | |
537 | * negative errno value is returned. | |
538 | */ | |
539 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
540 | { | |
541 | int id; | |
542 | int status; | |
543 | ||
544 | if (adap->nr & ~MAX_ID_MASK) | |
545 | return -EINVAL; | |
546 | ||
547 | retry: | |
548 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
549 | return -ENOMEM; | |
550 | ||
caada32a | 551 | mutex_lock(&core_lock); |
6e13e641 DB |
552 | /* "above" here means "above or equal to", sigh; |
553 | * we need the "equal to" result to force the result | |
554 | */ | |
555 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
556 | if (status == 0 && id != adap->nr) { | |
557 | status = -EBUSY; | |
558 | idr_remove(&i2c_adapter_idr, id); | |
559 | } | |
caada32a | 560 | mutex_unlock(&core_lock); |
6e13e641 DB |
561 | if (status == -EAGAIN) |
562 | goto retry; | |
563 | ||
564 | if (status == 0) | |
565 | status = i2c_register_adapter(adap); | |
566 | return status; | |
567 | } | |
568 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
569 | ||
026526f5 JD |
570 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
571 | { | |
572 | struct i2c_driver *driver = to_i2c_driver(d); | |
573 | struct i2c_adapter *adapter = data; | |
4735c98f | 574 | struct i2c_client *client, *_n; |
026526f5 JD |
575 | int res; |
576 | ||
4735c98f JD |
577 | /* Remove the devices we created ourselves */ |
578 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { | |
579 | if (client->adapter == adapter) { | |
580 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
581 | client->name, client->addr); | |
582 | list_del(&client->detected); | |
583 | i2c_unregister_device(client); | |
584 | } | |
585 | } | |
586 | ||
026526f5 JD |
587 | if (!driver->detach_adapter) |
588 | return 0; | |
589 | res = driver->detach_adapter(adapter); | |
590 | if (res) | |
591 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
592 | "for driver [%s]\n", res, driver->driver.name); | |
593 | return res; | |
594 | } | |
595 | ||
d64f73be DB |
596 | /** |
597 | * i2c_del_adapter - unregister I2C adapter | |
598 | * @adap: the adapter being unregistered | |
599 | * Context: can sleep | |
600 | * | |
601 | * This unregisters an I2C adapter which was previously registered | |
602 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
603 | */ | |
1da177e4 LT |
604 | int i2c_del_adapter(struct i2c_adapter *adap) |
605 | { | |
6a03cd93 | 606 | struct i2c_client *client, *_n; |
1da177e4 LT |
607 | int res = 0; |
608 | ||
caada32a | 609 | mutex_lock(&core_lock); |
1da177e4 LT |
610 | |
611 | /* First make sure that this adapter was ever added */ | |
87c6c229 | 612 | if (idr_find(&i2c_adapter_idr, adap->nr) != adap) { |
b6d7b3d1 JD |
613 | pr_debug("i2c-core: attempting to delete unregistered " |
614 | "adapter [%s]\n", adap->name); | |
1da177e4 LT |
615 | res = -EINVAL; |
616 | goto out_unlock; | |
617 | } | |
618 | ||
026526f5 JD |
619 | /* Tell drivers about this removal */ |
620 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, | |
621 | i2c_do_del_adapter); | |
622 | if (res) | |
623 | goto out_unlock; | |
1da177e4 LT |
624 | |
625 | /* detach any active clients. This must be done first, because | |
a551acc2 | 626 | * it can fail; in which case we give up. */ |
6a03cd93 | 627 | list_for_each_entry_safe(client, _n, &adap->clients, list) { |
a1d9e6e4 DB |
628 | struct i2c_driver *driver; |
629 | ||
a1d9e6e4 DB |
630 | driver = client->driver; |
631 | ||
632 | /* new style, follow standard driver model */ | |
633 | if (!driver || is_newstyle_driver(driver)) { | |
634 | i2c_unregister_device(client); | |
635 | continue; | |
636 | } | |
1da177e4 | 637 | |
a1d9e6e4 DB |
638 | /* legacy drivers create and remove clients themselves */ |
639 | if ((res = driver->detach_client(client))) { | |
b6d7b3d1 JD |
640 | dev_err(&adap->dev, "detach_client failed for client " |
641 | "[%s] at address 0x%02x\n", client->name, | |
1da177e4 LT |
642 | client->addr); |
643 | goto out_unlock; | |
644 | } | |
645 | } | |
646 | ||
647 | /* clean up the sysfs representation */ | |
648 | init_completion(&adap->dev_released); | |
1da177e4 | 649 | device_unregister(&adap->dev); |
1da177e4 LT |
650 | |
651 | /* wait for sysfs to drop all references */ | |
652 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 653 | |
6e13e641 | 654 | /* free bus id */ |
1da177e4 LT |
655 | idr_remove(&i2c_adapter_idr, adap->nr); |
656 | ||
b6d7b3d1 | 657 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 | 658 | |
bd4bc3db JD |
659 | /* Clear the device structure in case this adapter is ever going to be |
660 | added again */ | |
661 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
662 | ||
1da177e4 | 663 | out_unlock: |
caada32a | 664 | mutex_unlock(&core_lock); |
1da177e4 LT |
665 | return res; |
666 | } | |
c0564606 | 667 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
668 | |
669 | ||
7b4fbc50 DB |
670 | /* ------------------------------------------------------------------------- */ |
671 | ||
7f101a97 DY |
672 | static int __attach_adapter(struct device *dev, void *data) |
673 | { | |
674 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
675 | struct i2c_driver *driver = data; | |
676 | ||
4735c98f JD |
677 | i2c_detect(adapter, driver); |
678 | ||
679 | /* Legacy drivers scan i2c busses directly */ | |
680 | if (driver->attach_adapter) | |
681 | driver->attach_adapter(adapter); | |
7f101a97 DY |
682 | |
683 | return 0; | |
684 | } | |
685 | ||
7b4fbc50 DB |
686 | /* |
687 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
688 | * i2c slave chips, on a bus instance associated with some i2c_adapter. There | |
689 | * are two models for binding the driver to its device: "new style" drivers | |
690 | * follow the standard Linux driver model and just respond to probe() calls | |
691 | * issued if the driver core sees they match(); "legacy" drivers create device | |
692 | * nodes themselves. | |
1da177e4 LT |
693 | */ |
694 | ||
de59cf9e | 695 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 696 | { |
7eebcb7c | 697 | int res; |
1da177e4 | 698 | |
7b4fbc50 | 699 | /* new style driver methods can't mix with legacy ones */ |
a1d9e6e4 | 700 | if (is_newstyle_driver(driver)) { |
7b4fbc50 DB |
701 | if (driver->attach_adapter || driver->detach_adapter |
702 | || driver->detach_client) { | |
703 | printk(KERN_WARNING | |
704 | "i2c-core: driver [%s] is confused\n", | |
705 | driver->driver.name); | |
706 | return -EINVAL; | |
707 | } | |
708 | } | |
709 | ||
1da177e4 | 710 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 711 | driver->driver.owner = owner; |
1da177e4 | 712 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 713 | |
6e13e641 DB |
714 | /* for new style drivers, when registration returns the driver core |
715 | * will have called probe() for all matching-but-unbound devices. | |
716 | */ | |
1da177e4 LT |
717 | res = driver_register(&driver->driver); |
718 | if (res) | |
7eebcb7c | 719 | return res; |
438d6c2c | 720 | |
caada32a | 721 | mutex_lock(&core_lock); |
7eebcb7c | 722 | |
35d8b2e6 | 723 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 724 | |
4735c98f JD |
725 | INIT_LIST_HEAD(&driver->clients); |
726 | /* Walk the adapters that are already present */ | |
93562b53 GKH |
727 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
728 | __attach_adapter); | |
4ad4eac6 | 729 | |
7f101a97 DY |
730 | mutex_unlock(&core_lock); |
731 | return 0; | |
732 | } | |
733 | EXPORT_SYMBOL(i2c_register_driver); | |
734 | ||
735 | static int __detach_adapter(struct device *dev, void *data) | |
736 | { | |
737 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
738 | struct i2c_driver *driver = data; | |
4735c98f JD |
739 | struct i2c_client *client, *_n; |
740 | ||
741 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { | |
742 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
743 | client->name, client->addr); | |
744 | list_del(&client->detected); | |
745 | i2c_unregister_device(client); | |
746 | } | |
747 | ||
748 | if (is_newstyle_driver(driver)) | |
749 | return 0; | |
7f101a97 DY |
750 | |
751 | /* Have a look at each adapter, if clients of this driver are still | |
752 | * attached. If so, detach them to be able to kill the driver | |
753 | * afterwards. | |
754 | */ | |
755 | if (driver->detach_adapter) { | |
756 | if (driver->detach_adapter(adapter)) | |
757 | dev_err(&adapter->dev, | |
758 | "detach_adapter failed for driver [%s]\n", | |
759 | driver->driver.name); | |
760 | } else { | |
6a03cd93 | 761 | struct i2c_client *client, *_n; |
7f101a97 | 762 | |
6a03cd93 | 763 | list_for_each_entry_safe(client, _n, &adapter->clients, list) { |
7f101a97 DY |
764 | if (client->driver != driver) |
765 | continue; | |
766 | dev_dbg(&adapter->dev, | |
767 | "detaching client [%s] at 0x%02x\n", | |
768 | client->name, client->addr); | |
769 | if (driver->detach_client(client)) | |
770 | dev_err(&adapter->dev, "detach_client " | |
771 | "failed for client [%s] at 0x%02x\n", | |
772 | client->name, client->addr); | |
1da177e4 LT |
773 | } |
774 | } | |
775 | ||
7eebcb7c | 776 | return 0; |
1da177e4 LT |
777 | } |
778 | ||
a1d9e6e4 DB |
779 | /** |
780 | * i2c_del_driver - unregister I2C driver | |
781 | * @driver: the driver being unregistered | |
d64f73be | 782 | * Context: can sleep |
a1d9e6e4 | 783 | */ |
b3e82096 | 784 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 785 | { |
caada32a | 786 | mutex_lock(&core_lock); |
1da177e4 | 787 | |
93562b53 GKH |
788 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
789 | __detach_adapter); | |
1da177e4 LT |
790 | |
791 | driver_unregister(&driver->driver); | |
35d8b2e6 | 792 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 793 | |
caada32a | 794 | mutex_unlock(&core_lock); |
1da177e4 | 795 | } |
c0564606 | 796 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 797 | |
7b4fbc50 DB |
798 | /* ------------------------------------------------------------------------- */ |
799 | ||
9b766b81 | 800 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 801 | { |
9b766b81 DB |
802 | struct i2c_client *client = i2c_verify_client(dev); |
803 | int addr = *(int *)addrp; | |
1da177e4 | 804 | |
9b766b81 DB |
805 | if (client && client->addr == addr) |
806 | return -EBUSY; | |
1da177e4 LT |
807 | return 0; |
808 | } | |
809 | ||
5e31c2bd | 810 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 811 | { |
9b766b81 | 812 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
813 | } |
814 | ||
815 | int i2c_attach_client(struct i2c_client *client) | |
816 | { | |
817 | struct i2c_adapter *adapter = client->adapter; | |
c1159f9e JD |
818 | int res; |
819 | ||
820 | /* Check for address business */ | |
821 | res = i2c_check_addr(adapter, client->addr); | |
822 | if (res) | |
823 | return res; | |
1da177e4 | 824 | |
1da177e4 | 825 | client->dev.parent = &client->adapter->dev; |
1da177e4 | 826 | client->dev.bus = &i2c_bus_type; |
9c1600ed DB |
827 | |
828 | if (client->driver) | |
829 | client->dev.driver = &client->driver->driver; | |
830 | ||
de81d2aa | 831 | if (client->driver && !is_newstyle_driver(client->driver)) { |
9c1600ed | 832 | client->dev.release = i2c_client_release; |
de81d2aa DB |
833 | client->dev.uevent_suppress = 1; |
834 | } else | |
9c1600ed | 835 | client->dev.release = i2c_client_dev_release; |
438d6c2c | 836 | |
1da177e4 LT |
837 | snprintf(&client->dev.bus_id[0], sizeof(client->dev.bus_id), |
838 | "%d-%04x", i2c_adapter_id(adapter), client->addr); | |
b119c6c9 JD |
839 | res = device_register(&client->dev); |
840 | if (res) | |
86ec5ec8 DB |
841 | goto out_err; |
842 | ||
843 | mutex_lock(&adapter->clist_lock); | |
844 | list_add_tail(&client->list, &adapter->clients); | |
b119c6c9 | 845 | mutex_unlock(&adapter->clist_lock); |
77ed74da | 846 | |
86ec5ec8 DB |
847 | dev_dbg(&adapter->dev, "client [%s] registered with bus id %s\n", |
848 | client->name, client->dev.bus_id); | |
849 | ||
77ed74da JD |
850 | if (adapter->client_register) { |
851 | if (adapter->client_register(client)) { | |
852 | dev_dbg(&adapter->dev, "client_register " | |
853 | "failed for client [%s] at 0x%02x\n", | |
854 | client->name, client->addr); | |
855 | } | |
856 | } | |
857 | ||
858 | return 0; | |
b119c6c9 | 859 | |
86ec5ec8 | 860 | out_err: |
b119c6c9 JD |
861 | dev_err(&adapter->dev, "Failed to attach i2c client %s at 0x%02x " |
862 | "(%d)\n", client->name, client->addr, res); | |
77ed74da | 863 | return res; |
1da177e4 | 864 | } |
c0564606 | 865 | EXPORT_SYMBOL(i2c_attach_client); |
1da177e4 LT |
866 | |
867 | int i2c_detach_client(struct i2c_client *client) | |
868 | { | |
869 | struct i2c_adapter *adapter = client->adapter; | |
870 | int res = 0; | |
438d6c2c | 871 | |
1da177e4 LT |
872 | if (adapter->client_unregister) { |
873 | res = adapter->client_unregister(client); | |
874 | if (res) { | |
875 | dev_err(&client->dev, | |
86749e85 JD |
876 | "client_unregister [%s] failed, " |
877 | "client not detached\n", client->name); | |
1da177e4 LT |
878 | goto out; |
879 | } | |
880 | } | |
881 | ||
5c085d36 | 882 | mutex_lock(&adapter->clist_lock); |
1da177e4 | 883 | list_del(&client->list); |
9ddced16 JD |
884 | mutex_unlock(&adapter->clist_lock); |
885 | ||
1da177e4 | 886 | init_completion(&client->released); |
1da177e4 | 887 | device_unregister(&client->dev); |
1da177e4 LT |
888 | wait_for_completion(&client->released); |
889 | ||
890 | out: | |
891 | return res; | |
892 | } | |
c0564606 | 893 | EXPORT_SYMBOL(i2c_detach_client); |
1da177e4 | 894 | |
e48d3319 JD |
895 | /** |
896 | * i2c_use_client - increments the reference count of the i2c client structure | |
897 | * @client: the client being referenced | |
898 | * | |
899 | * Each live reference to a client should be refcounted. The driver model does | |
900 | * that automatically as part of driver binding, so that most drivers don't | |
901 | * need to do this explicitly: they hold a reference until they're unbound | |
902 | * from the device. | |
903 | * | |
904 | * A pointer to the client with the incremented reference counter is returned. | |
905 | */ | |
906 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 907 | { |
6ea438ec DB |
908 | if (client && get_device(&client->dev)) |
909 | return client; | |
910 | return NULL; | |
1da177e4 | 911 | } |
c0564606 | 912 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 913 | |
e48d3319 JD |
914 | /** |
915 | * i2c_release_client - release a use of the i2c client structure | |
916 | * @client: the client being no longer referenced | |
917 | * | |
918 | * Must be called when a user of a client is finished with it. | |
919 | */ | |
920 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 921 | { |
6ea438ec DB |
922 | if (client) |
923 | put_device(&client->dev); | |
1da177e4 | 924 | } |
c0564606 | 925 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 926 | |
9b766b81 DB |
927 | struct i2c_cmd_arg { |
928 | unsigned cmd; | |
929 | void *arg; | |
930 | }; | |
931 | ||
932 | static int i2c_cmd(struct device *dev, void *_arg) | |
933 | { | |
934 | struct i2c_client *client = i2c_verify_client(dev); | |
935 | struct i2c_cmd_arg *arg = _arg; | |
936 | ||
937 | if (client && client->driver && client->driver->command) | |
938 | client->driver->command(client, arg->cmd, arg->arg); | |
939 | return 0; | |
940 | } | |
941 | ||
1da177e4 LT |
942 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
943 | { | |
9b766b81 | 944 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 945 | |
9b766b81 DB |
946 | cmd_arg.cmd = cmd; |
947 | cmd_arg.arg = arg; | |
948 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 949 | } |
c0564606 | 950 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
951 | |
952 | static int __init i2c_init(void) | |
953 | { | |
954 | int retval; | |
955 | ||
956 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
957 | if (retval) |
958 | return retval; | |
e9f1373b DB |
959 | retval = class_register(&i2c_adapter_class); |
960 | if (retval) | |
961 | goto bus_err; | |
962 | retval = i2c_add_driver(&dummy_driver); | |
963 | if (retval) | |
964 | goto class_err; | |
965 | return 0; | |
966 | ||
967 | class_err: | |
968 | class_unregister(&i2c_adapter_class); | |
969 | bus_err: | |
970 | bus_unregister(&i2c_bus_type); | |
971 | return retval; | |
1da177e4 LT |
972 | } |
973 | ||
974 | static void __exit i2c_exit(void) | |
975 | { | |
e9f1373b | 976 | i2c_del_driver(&dummy_driver); |
1da177e4 | 977 | class_unregister(&i2c_adapter_class); |
1da177e4 LT |
978 | bus_unregister(&i2c_bus_type); |
979 | } | |
980 | ||
981 | subsys_initcall(i2c_init); | |
982 | module_exit(i2c_exit); | |
983 | ||
984 | /* ---------------------------------------------------- | |
985 | * the functional interface to the i2c busses. | |
986 | * ---------------------------------------------------- | |
987 | */ | |
988 | ||
a1cdedac DB |
989 | /** |
990 | * i2c_transfer - execute a single or combined I2C message | |
991 | * @adap: Handle to I2C bus | |
992 | * @msgs: One or more messages to execute before STOP is issued to | |
993 | * terminate the operation; each message begins with a START. | |
994 | * @num: Number of messages to be executed. | |
995 | * | |
996 | * Returns negative errno, else the number of messages executed. | |
997 | * | |
998 | * Note that there is no requirement that each message be sent to | |
999 | * the same slave address, although that is the most common model. | |
1000 | */ | |
1da177e4 LT |
1001 | int i2c_transfer(struct i2c_adapter * adap, struct i2c_msg *msgs, int num) |
1002 | { | |
1003 | int ret; | |
1004 | ||
a1cdedac DB |
1005 | /* REVISIT the fault reporting model here is weak: |
1006 | * | |
1007 | * - When we get an error after receiving N bytes from a slave, | |
1008 | * there is no way to report "N". | |
1009 | * | |
1010 | * - When we get a NAK after transmitting N bytes to a slave, | |
1011 | * there is no way to report "N" ... or to let the master | |
1012 | * continue executing the rest of this combined message, if | |
1013 | * that's the appropriate response. | |
1014 | * | |
1015 | * - When for example "num" is two and we successfully complete | |
1016 | * the first message but get an error part way through the | |
1017 | * second, it's unclear whether that should be reported as | |
1018 | * one (discarding status on the second message) or errno | |
1019 | * (discarding status on the first one). | |
1020 | */ | |
1021 | ||
1da177e4 LT |
1022 | if (adap->algo->master_xfer) { |
1023 | #ifdef DEBUG | |
1024 | for (ret = 0; ret < num; ret++) { | |
1025 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1026 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1027 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1028 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1029 | } |
1030 | #endif | |
1031 | ||
cea443a8 MR |
1032 | if (in_atomic() || irqs_disabled()) { |
1033 | ret = mutex_trylock(&adap->bus_lock); | |
1034 | if (!ret) | |
1035 | /* I2C activity is ongoing. */ | |
1036 | return -EAGAIN; | |
1037 | } else { | |
1038 | mutex_lock_nested(&adap->bus_lock, adap->level); | |
1039 | } | |
1040 | ||
1da177e4 | 1041 | ret = adap->algo->master_xfer(adap,msgs,num); |
5c085d36 | 1042 | mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1043 | |
1044 | return ret; | |
1045 | } else { | |
1046 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1047 | return -EOPNOTSUPP; |
1da177e4 LT |
1048 | } |
1049 | } | |
c0564606 | 1050 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1051 | |
a1cdedac DB |
1052 | /** |
1053 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1054 | * @client: Handle to slave device | |
1055 | * @buf: Data that will be written to the slave | |
1056 | * @count: How many bytes to write | |
1057 | * | |
1058 | * Returns negative errno, or else the number of bytes written. | |
1059 | */ | |
1da177e4 LT |
1060 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1061 | { | |
1062 | int ret; | |
1063 | struct i2c_adapter *adap=client->adapter; | |
1064 | struct i2c_msg msg; | |
1065 | ||
815f55f2 JD |
1066 | msg.addr = client->addr; |
1067 | msg.flags = client->flags & I2C_M_TEN; | |
1068 | msg.len = count; | |
1069 | msg.buf = (char *)buf; | |
438d6c2c | 1070 | |
815f55f2 | 1071 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1072 | |
815f55f2 JD |
1073 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1074 | transmitted, else error code. */ | |
1075 | return (ret == 1) ? count : ret; | |
1da177e4 | 1076 | } |
c0564606 | 1077 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1078 | |
a1cdedac DB |
1079 | /** |
1080 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1081 | * @client: Handle to slave device | |
1082 | * @buf: Where to store data read from slave | |
1083 | * @count: How many bytes to read | |
1084 | * | |
1085 | * Returns negative errno, or else the number of bytes read. | |
1086 | */ | |
1da177e4 LT |
1087 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1088 | { | |
1089 | struct i2c_adapter *adap=client->adapter; | |
1090 | struct i2c_msg msg; | |
1091 | int ret; | |
815f55f2 JD |
1092 | |
1093 | msg.addr = client->addr; | |
1094 | msg.flags = client->flags & I2C_M_TEN; | |
1095 | msg.flags |= I2C_M_RD; | |
1096 | msg.len = count; | |
1097 | msg.buf = buf; | |
1098 | ||
1099 | ret = i2c_transfer(adap, &msg, 1); | |
1100 | ||
1101 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1102 | transmitted, else error code. */ | |
1103 | return (ret == 1) ? count : ret; | |
1da177e4 | 1104 | } |
c0564606 | 1105 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1106 | |
1da177e4 LT |
1107 | /* ---------------------------------------------------- |
1108 | * the i2c address scanning function | |
1109 | * Will not work for 10-bit addresses! | |
1110 | * ---------------------------------------------------- | |
1111 | */ | |
a89ba0bc JD |
1112 | static int i2c_probe_address(struct i2c_adapter *adapter, int addr, int kind, |
1113 | int (*found_proc) (struct i2c_adapter *, int, int)) | |
1114 | { | |
1115 | int err; | |
1116 | ||
1117 | /* Make sure the address is valid */ | |
1118 | if (addr < 0x03 || addr > 0x77) { | |
1119 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1120 | addr); | |
1121 | return -EINVAL; | |
9fc6adfa JD |
1122 | } |
1123 | ||
a89ba0bc JD |
1124 | /* Skip if already in use */ |
1125 | if (i2c_check_addr(adapter, addr)) | |
1126 | return 0; | |
1127 | ||
1128 | /* Make sure there is something at this address, unless forced */ | |
4c9337da JD |
1129 | if (kind < 0) { |
1130 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1131 | I2C_SMBUS_QUICK, NULL) < 0) | |
1132 | return 0; | |
1133 | ||
1134 | /* prevent 24RF08 corruption */ | |
1135 | if ((addr & ~0x0f) == 0x50) | |
1136 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1137 | I2C_SMBUS_QUICK, NULL); | |
1138 | } | |
a89ba0bc JD |
1139 | |
1140 | /* Finally call the custom detection function */ | |
1141 | err = found_proc(adapter, addr, kind); | |
a89ba0bc JD |
1142 | /* -ENODEV can be returned if there is a chip at the given address |
1143 | but it isn't supported by this chip driver. We catch it here as | |
1144 | this isn't an error. */ | |
114fd183 JD |
1145 | if (err == -ENODEV) |
1146 | err = 0; | |
1147 | ||
1148 | if (err) | |
1149 | dev_warn(&adapter->dev, "Client creation failed at 0x%x (%d)\n", | |
1150 | addr, err); | |
1151 | return err; | |
9fc6adfa JD |
1152 | } |
1153 | ||
1da177e4 | 1154 | int i2c_probe(struct i2c_adapter *adapter, |
bfb6df24 | 1155 | const struct i2c_client_address_data *address_data, |
1da177e4 LT |
1156 | int (*found_proc) (struct i2c_adapter *, int, int)) |
1157 | { | |
a89ba0bc | 1158 | int i, err; |
1da177e4 LT |
1159 | int adap_id = i2c_adapter_id(adapter); |
1160 | ||
a89ba0bc JD |
1161 | /* Force entries are done first, and are not affected by ignore |
1162 | entries */ | |
1163 | if (address_data->forces) { | |
bfb6df24 | 1164 | const unsigned short * const *forces = address_data->forces; |
a89ba0bc JD |
1165 | int kind; |
1166 | ||
1167 | for (kind = 0; forces[kind]; kind++) { | |
1168 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1169 | i += 2) { | |
1170 | if (forces[kind][i] == adap_id | |
1171 | || forces[kind][i] == ANY_I2C_BUS) { | |
1172 | dev_dbg(&adapter->dev, "found force " | |
1173 | "parameter for adapter %d, " | |
1174 | "addr 0x%02x, kind %d\n", | |
1175 | adap_id, forces[kind][i + 1], | |
1176 | kind); | |
1177 | err = i2c_probe_address(adapter, | |
1178 | forces[kind][i + 1], | |
1179 | kind, found_proc); | |
1180 | if (err) | |
1181 | return err; | |
1182 | } | |
1da177e4 LT |
1183 | } |
1184 | } | |
a89ba0bc | 1185 | } |
1da177e4 | 1186 | |
4366dc94 JD |
1187 | /* Stop here if we can't use SMBUS_QUICK */ |
1188 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1189 | if (address_data->probe[0] == I2C_CLIENT_END | |
1190 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
438d6c2c | 1191 | return 0; |
4366dc94 JD |
1192 | |
1193 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1194 | "can't probe for chips\n"); | |
24a5bb7b | 1195 | return -EOPNOTSUPP; |
4366dc94 JD |
1196 | } |
1197 | ||
a89ba0bc JD |
1198 | /* Probe entries are done second, and are not affected by ignore |
1199 | entries either */ | |
1200 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1201 | if (address_data->probe[i] == adap_id | |
1202 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1203 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1204 | "adapter %d, addr 0x%02x\n", adap_id, | |
1205 | address_data->probe[i + 1]); | |
1206 | err = i2c_probe_address(adapter, | |
1207 | address_data->probe[i + 1], | |
1208 | -1, found_proc); | |
1209 | if (err) | |
1210 | return err; | |
1da177e4 | 1211 | } |
a89ba0bc | 1212 | } |
1da177e4 | 1213 | |
a89ba0bc JD |
1214 | /* Normal entries are done last, unless shadowed by an ignore entry */ |
1215 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1216 | int j, ignore; | |
1217 | ||
1218 | ignore = 0; | |
1219 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1220 | j += 2) { | |
1221 | if ((address_data->ignore[j] == adap_id || | |
1222 | address_data->ignore[j] == ANY_I2C_BUS) | |
1223 | && address_data->ignore[j + 1] | |
1224 | == address_data->normal_i2c[i]) { | |
1225 | dev_dbg(&adapter->dev, "found ignore " | |
1226 | "parameter for adapter %d, " | |
1227 | "addr 0x%02x\n", adap_id, | |
1228 | address_data->ignore[j + 1]); | |
2369df93 MH |
1229 | ignore = 1; |
1230 | break; | |
1da177e4 LT |
1231 | } |
1232 | } | |
a89ba0bc | 1233 | if (ignore) |
1da177e4 LT |
1234 | continue; |
1235 | ||
a89ba0bc JD |
1236 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
1237 | "addr 0x%02x\n", adap_id, | |
1238 | address_data->normal_i2c[i]); | |
1239 | err = i2c_probe_address(adapter, address_data->normal_i2c[i], | |
1240 | -1, found_proc); | |
1241 | if (err) | |
1242 | return err; | |
1da177e4 | 1243 | } |
a89ba0bc | 1244 | |
1da177e4 LT |
1245 | return 0; |
1246 | } | |
c0564606 | 1247 | EXPORT_SYMBOL(i2c_probe); |
1da177e4 | 1248 | |
4735c98f JD |
1249 | /* Separate detection function for new-style drivers */ |
1250 | static int i2c_detect_address(struct i2c_client *temp_client, int kind, | |
1251 | struct i2c_driver *driver) | |
1252 | { | |
1253 | struct i2c_board_info info; | |
1254 | struct i2c_adapter *adapter = temp_client->adapter; | |
1255 | int addr = temp_client->addr; | |
1256 | int err; | |
1257 | ||
1258 | /* Make sure the address is valid */ | |
1259 | if (addr < 0x03 || addr > 0x77) { | |
1260 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1261 | addr); | |
1262 | return -EINVAL; | |
1263 | } | |
1264 | ||
1265 | /* Skip if already in use */ | |
1266 | if (i2c_check_addr(adapter, addr)) | |
1267 | return 0; | |
1268 | ||
1269 | /* Make sure there is something at this address, unless forced */ | |
1270 | if (kind < 0) { | |
1271 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1272 | I2C_SMBUS_QUICK, NULL) < 0) | |
1273 | return 0; | |
1274 | ||
1275 | /* prevent 24RF08 corruption */ | |
1276 | if ((addr & ~0x0f) == 0x50) | |
1277 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1278 | I2C_SMBUS_QUICK, NULL); | |
1279 | } | |
1280 | ||
1281 | /* Finally call the custom detection function */ | |
1282 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1283 | info.addr = addr; | |
1284 | err = driver->detect(temp_client, kind, &info); | |
1285 | if (err) { | |
1286 | /* -ENODEV is returned if the detection fails. We catch it | |
1287 | here as this isn't an error. */ | |
1288 | return err == -ENODEV ? 0 : err; | |
1289 | } | |
1290 | ||
1291 | /* Consistency check */ | |
1292 | if (info.type[0] == '\0') { | |
1293 | dev_err(&adapter->dev, "%s detection function provided " | |
1294 | "no name for 0x%x\n", driver->driver.name, | |
1295 | addr); | |
1296 | } else { | |
1297 | struct i2c_client *client; | |
1298 | ||
1299 | /* Detection succeeded, instantiate the device */ | |
1300 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1301 | info.type, info.addr); | |
1302 | client = i2c_new_device(adapter, &info); | |
1303 | if (client) | |
1304 | list_add_tail(&client->detected, &driver->clients); | |
1305 | else | |
1306 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1307 | info.type, info.addr); | |
1308 | } | |
1309 | return 0; | |
1310 | } | |
1311 | ||
1312 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1313 | { | |
1314 | const struct i2c_client_address_data *address_data; | |
1315 | struct i2c_client *temp_client; | |
1316 | int i, err = 0; | |
1317 | int adap_id = i2c_adapter_id(adapter); | |
1318 | ||
1319 | address_data = driver->address_data; | |
1320 | if (!driver->detect || !address_data) | |
1321 | return 0; | |
1322 | ||
1323 | /* Set up a temporary client to help detect callback */ | |
1324 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1325 | if (!temp_client) | |
1326 | return -ENOMEM; | |
1327 | temp_client->adapter = adapter; | |
1328 | ||
1329 | /* Force entries are done first, and are not affected by ignore | |
1330 | entries */ | |
1331 | if (address_data->forces) { | |
1332 | const unsigned short * const *forces = address_data->forces; | |
1333 | int kind; | |
1334 | ||
1335 | for (kind = 0; forces[kind]; kind++) { | |
1336 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1337 | i += 2) { | |
1338 | if (forces[kind][i] == adap_id | |
1339 | || forces[kind][i] == ANY_I2C_BUS) { | |
1340 | dev_dbg(&adapter->dev, "found force " | |
1341 | "parameter for adapter %d, " | |
1342 | "addr 0x%02x, kind %d\n", | |
1343 | adap_id, forces[kind][i + 1], | |
1344 | kind); | |
1345 | temp_client->addr = forces[kind][i + 1]; | |
1346 | err = i2c_detect_address(temp_client, | |
1347 | kind, driver); | |
1348 | if (err) | |
1349 | goto exit_free; | |
1350 | } | |
1351 | } | |
1352 | } | |
1353 | } | |
1354 | ||
1355 | /* Stop here if we can't use SMBUS_QUICK */ | |
1356 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1357 | if (address_data->probe[0] == I2C_CLIENT_END | |
1358 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
1359 | goto exit_free; | |
1360 | ||
1361 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1362 | "can't probe for chips\n"); | |
1363 | err = -EOPNOTSUPP; | |
1364 | goto exit_free; | |
1365 | } | |
1366 | ||
1367 | /* Stop here if the classes do not match */ | |
1368 | if (!(adapter->class & driver->class)) | |
1369 | goto exit_free; | |
1370 | ||
1371 | /* Probe entries are done second, and are not affected by ignore | |
1372 | entries either */ | |
1373 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1374 | if (address_data->probe[i] == adap_id | |
1375 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1376 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1377 | "adapter %d, addr 0x%02x\n", adap_id, | |
1378 | address_data->probe[i + 1]); | |
1379 | temp_client->addr = address_data->probe[i + 1]; | |
1380 | err = i2c_detect_address(temp_client, -1, driver); | |
1381 | if (err) | |
1382 | goto exit_free; | |
1383 | } | |
1384 | } | |
1385 | ||
1386 | /* Normal entries are done last, unless shadowed by an ignore entry */ | |
1387 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1388 | int j, ignore; | |
1389 | ||
1390 | ignore = 0; | |
1391 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1392 | j += 2) { | |
1393 | if ((address_data->ignore[j] == adap_id || | |
1394 | address_data->ignore[j] == ANY_I2C_BUS) | |
1395 | && address_data->ignore[j + 1] | |
1396 | == address_data->normal_i2c[i]) { | |
1397 | dev_dbg(&adapter->dev, "found ignore " | |
1398 | "parameter for adapter %d, " | |
1399 | "addr 0x%02x\n", adap_id, | |
1400 | address_data->ignore[j + 1]); | |
1401 | ignore = 1; | |
1402 | break; | |
1403 | } | |
1404 | } | |
1405 | if (ignore) | |
1406 | continue; | |
1407 | ||
1408 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " | |
1409 | "addr 0x%02x\n", adap_id, | |
1410 | address_data->normal_i2c[i]); | |
1411 | temp_client->addr = address_data->normal_i2c[i]; | |
1412 | err = i2c_detect_address(temp_client, -1, driver); | |
1413 | if (err) | |
1414 | goto exit_free; | |
1415 | } | |
1416 | ||
1417 | exit_free: | |
1418 | kfree(temp_client); | |
1419 | return err; | |
1420 | } | |
1421 | ||
12b5053a JD |
1422 | struct i2c_client * |
1423 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1424 | struct i2c_board_info *info, | |
1425 | unsigned short const *addr_list) | |
1426 | { | |
1427 | int i; | |
1428 | ||
1429 | /* Stop here if the bus doesn't support probing */ | |
1430 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1431 | dev_err(&adap->dev, "Probing not supported\n"); | |
1432 | return NULL; | |
1433 | } | |
1434 | ||
12b5053a JD |
1435 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1436 | /* Check address validity */ | |
1437 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1438 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1439 | "0x%02x\n", addr_list[i]); | |
1440 | continue; | |
1441 | } | |
1442 | ||
1443 | /* Check address availability */ | |
9b766b81 | 1444 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1445 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1446 | "use, not probing\n", addr_list[i]); | |
1447 | continue; | |
1448 | } | |
1449 | ||
1450 | /* Test address responsiveness | |
1451 | The default probe method is a quick write, but it is known | |
1452 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1453 | and could also irreversibly write-protect some EEPROMs, so | |
1454 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1455 | read instead. Also, some bus drivers don't implement | |
1456 | quick write, so we fallback to a byte read it that case | |
1457 | too. */ | |
1458 | if ((addr_list[i] & ~0x07) == 0x30 | |
1459 | || (addr_list[i] & ~0x0f) == 0x50 | |
1460 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1461 | union i2c_smbus_data data; |
1462 | ||
12b5053a JD |
1463 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1464 | I2C_SMBUS_READ, 0, | |
b25b791b | 1465 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1466 | break; |
1467 | } else { | |
1468 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1469 | I2C_SMBUS_WRITE, 0, | |
1470 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1471 | break; | |
1472 | } | |
1473 | } | |
12b5053a JD |
1474 | |
1475 | if (addr_list[i] == I2C_CLIENT_END) { | |
1476 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1477 | return NULL; | |
1478 | } | |
1479 | ||
1480 | info->addr = addr_list[i]; | |
1481 | return i2c_new_device(adap, info); | |
1482 | } | |
1483 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1484 | ||
1da177e4 LT |
1485 | struct i2c_adapter* i2c_get_adapter(int id) |
1486 | { | |
1da177e4 | 1487 | struct i2c_adapter *adapter; |
438d6c2c | 1488 | |
caada32a | 1489 | mutex_lock(&core_lock); |
a0920e10 MH |
1490 | adapter = (struct i2c_adapter *)idr_find(&i2c_adapter_idr, id); |
1491 | if (adapter && !try_module_get(adapter->owner)) | |
1492 | adapter = NULL; | |
1493 | ||
caada32a | 1494 | mutex_unlock(&core_lock); |
a0920e10 | 1495 | return adapter; |
1da177e4 | 1496 | } |
c0564606 | 1497 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1498 | |
1499 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1500 | { | |
1501 | module_put(adap->owner); | |
1502 | } | |
c0564606 | 1503 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1504 | |
1505 | /* The SMBus parts */ | |
1506 | ||
438d6c2c | 1507 | #define POLY (0x1070U << 3) |
1da177e4 LT |
1508 | static u8 |
1509 | crc8(u16 data) | |
1510 | { | |
1511 | int i; | |
438d6c2c | 1512 | |
1da177e4 | 1513 | for(i = 0; i < 8; i++) { |
438d6c2c | 1514 | if (data & 0x8000) |
1da177e4 LT |
1515 | data = data ^ POLY; |
1516 | data = data << 1; | |
1517 | } | |
1518 | return (u8)(data >> 8); | |
1519 | } | |
1520 | ||
421ef47b JD |
1521 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1522 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1523 | { |
1524 | int i; | |
1525 | ||
1526 | for(i = 0; i < count; i++) | |
421ef47b | 1527 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1528 | return crc; |
1529 | } | |
1530 | ||
421ef47b JD |
1531 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1532 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1533 | { |
421ef47b JD |
1534 | /* The address will be sent first */ |
1535 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1536 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1537 | ||
1538 | /* The data buffer follows */ | |
1539 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1540 | } |
1541 | ||
421ef47b JD |
1542 | /* Used for write only transactions */ |
1543 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1544 | { |
421ef47b JD |
1545 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1546 | msg->len++; | |
1da177e4 LT |
1547 | } |
1548 | ||
421ef47b JD |
1549 | /* Return <0 on CRC error |
1550 | If there was a write before this read (most cases) we need to take the | |
1551 | partial CRC from the write part into account. | |
1552 | Note that this function does modify the message (we need to decrease the | |
1553 | message length to hide the CRC byte from the caller). */ | |
1554 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1555 | { |
421ef47b JD |
1556 | u8 rpec = msg->buf[--msg->len]; |
1557 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1558 | |
1da177e4 LT |
1559 | if (rpec != cpec) { |
1560 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1561 | rpec, cpec); | |
24a5bb7b | 1562 | return -EBADMSG; |
1da177e4 | 1563 | } |
438d6c2c | 1564 | return 0; |
1da177e4 LT |
1565 | } |
1566 | ||
a1cdedac DB |
1567 | /** |
1568 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1569 | * @client: Handle to slave device | |
1570 | * | |
1571 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1572 | * else the byte received from the device. | |
1573 | */ | |
1da177e4 LT |
1574 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1575 | { | |
1576 | union i2c_smbus_data data; | |
24a5bb7b DB |
1577 | int status; |
1578 | ||
1579 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1580 | I2C_SMBUS_READ, 0, | |
1581 | I2C_SMBUS_BYTE, &data); | |
1582 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1583 | } |
c0564606 | 1584 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1585 | |
a1cdedac DB |
1586 | /** |
1587 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1588 | * @client: Handle to slave device | |
1589 | * @value: Byte to be sent | |
1590 | * | |
1591 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1592 | * else zero on success. | |
1593 | */ | |
1da177e4 LT |
1594 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1595 | { | |
1da177e4 | 1596 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1597 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1598 | } |
c0564606 | 1599 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1600 | |
a1cdedac DB |
1601 | /** |
1602 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1603 | * @client: Handle to slave device | |
1604 | * @command: Byte interpreted by slave | |
1605 | * | |
1606 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1607 | * else a data byte received from the device. | |
1608 | */ | |
1da177e4 LT |
1609 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1610 | { | |
1611 | union i2c_smbus_data data; | |
24a5bb7b DB |
1612 | int status; |
1613 | ||
1614 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1615 | I2C_SMBUS_READ, command, | |
1616 | I2C_SMBUS_BYTE_DATA, &data); | |
1617 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1618 | } |
c0564606 | 1619 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1620 | |
a1cdedac DB |
1621 | /** |
1622 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1623 | * @client: Handle to slave device | |
1624 | * @command: Byte interpreted by slave | |
1625 | * @value: Byte being written | |
1626 | * | |
1627 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1628 | * else zero on success. | |
1629 | */ | |
1da177e4 LT |
1630 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1631 | { | |
1632 | union i2c_smbus_data data; | |
1633 | data.byte = value; | |
1634 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1635 | I2C_SMBUS_WRITE,command, | |
1636 | I2C_SMBUS_BYTE_DATA,&data); | |
1637 | } | |
c0564606 | 1638 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1639 | |
a1cdedac DB |
1640 | /** |
1641 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1642 | * @client: Handle to slave device | |
1643 | * @command: Byte interpreted by slave | |
1644 | * | |
1645 | * This executes the SMBus "read word" protocol, returning negative errno | |
1646 | * else a 16-bit unsigned "word" received from the device. | |
1647 | */ | |
1da177e4 LT |
1648 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1649 | { | |
1650 | union i2c_smbus_data data; | |
24a5bb7b DB |
1651 | int status; |
1652 | ||
1653 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1654 | I2C_SMBUS_READ, command, | |
1655 | I2C_SMBUS_WORD_DATA, &data); | |
1656 | return (status < 0) ? status : data.word; | |
1da177e4 | 1657 | } |
c0564606 | 1658 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1659 | |
a1cdedac DB |
1660 | /** |
1661 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1662 | * @client: Handle to slave device | |
1663 | * @command: Byte interpreted by slave | |
1664 | * @value: 16-bit "word" being written | |
1665 | * | |
1666 | * This executes the SMBus "write word" protocol, returning negative errno | |
1667 | * else zero on success. | |
1668 | */ | |
1da177e4 LT |
1669 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1670 | { | |
1671 | union i2c_smbus_data data; | |
1672 | data.word = value; | |
1673 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1674 | I2C_SMBUS_WRITE,command, | |
1675 | I2C_SMBUS_WORD_DATA,&data); | |
1676 | } | |
c0564606 | 1677 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1678 | |
a64ec07d | 1679 | /** |
a1cdedac | 1680 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1681 | * @client: Handle to slave device |
a1cdedac | 1682 | * @command: Byte interpreted by slave |
a64ec07d DB |
1683 | * @values: Byte array into which data will be read; big enough to hold |
1684 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1685 | * | |
a1cdedac DB |
1686 | * This executes the SMBus "block read" protocol, returning negative errno |
1687 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1688 | * |
1689 | * Note that using this function requires that the client's adapter support | |
1690 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1691 | * support this; its emulation through I2C messaging relies on a specific | |
1692 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1693 | */ | |
b86a1bc8 JD |
1694 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1695 | u8 *values) | |
1696 | { | |
1697 | union i2c_smbus_data data; | |
24a5bb7b | 1698 | int status; |
b86a1bc8 | 1699 | |
24a5bb7b DB |
1700 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1701 | I2C_SMBUS_READ, command, | |
1702 | I2C_SMBUS_BLOCK_DATA, &data); | |
1703 | if (status) | |
1704 | return status; | |
b86a1bc8 JD |
1705 | |
1706 | memcpy(values, &data.block[1], data.block[0]); | |
1707 | return data.block[0]; | |
1708 | } | |
1709 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1710 | ||
a1cdedac DB |
1711 | /** |
1712 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1713 | * @client: Handle to slave device | |
1714 | * @command: Byte interpreted by slave | |
1715 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1716 | * @values: Byte array which will be written. | |
1717 | * | |
1718 | * This executes the SMBus "block write" protocol, returning negative errno | |
1719 | * else zero on success. | |
1720 | */ | |
1da177e4 | 1721 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1722 | u8 length, const u8 *values) |
1da177e4 LT |
1723 | { |
1724 | union i2c_smbus_data data; | |
7656032b | 1725 | |
1da177e4 LT |
1726 | if (length > I2C_SMBUS_BLOCK_MAX) |
1727 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1728 | data.block[0] = length; |
7656032b | 1729 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1730 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1731 | I2C_SMBUS_WRITE,command, | |
1732 | I2C_SMBUS_BLOCK_DATA,&data); | |
1733 | } | |
c0564606 | 1734 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1735 | |
1736 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1737 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1738 | u8 length, u8 *values) | |
1da177e4 LT |
1739 | { |
1740 | union i2c_smbus_data data; | |
24a5bb7b | 1741 | int status; |
7656032b | 1742 | |
4b2643d7 JD |
1743 | if (length > I2C_SMBUS_BLOCK_MAX) |
1744 | length = I2C_SMBUS_BLOCK_MAX; | |
1745 | data.block[0] = length; | |
24a5bb7b DB |
1746 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1747 | I2C_SMBUS_READ, command, | |
1748 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1749 | if (status < 0) | |
1750 | return status; | |
7656032b JD |
1751 | |
1752 | memcpy(values, &data.block[1], data.block[0]); | |
1753 | return data.block[0]; | |
1da177e4 | 1754 | } |
c0564606 | 1755 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1756 | |
21bbd691 | 1757 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1758 | u8 length, const u8 *values) |
21bbd691 JD |
1759 | { |
1760 | union i2c_smbus_data data; | |
1761 | ||
1762 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1763 | length = I2C_SMBUS_BLOCK_MAX; | |
1764 | data.block[0] = length; | |
1765 | memcpy(data.block + 1, values, length); | |
1766 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1767 | I2C_SMBUS_WRITE, command, | |
1768 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1769 | } | |
c0564606 | 1770 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1771 | |
438d6c2c | 1772 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1773 | No checking of parameters is done! */ |
438d6c2c | 1774 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1775 | unsigned short flags, |
438d6c2c | 1776 | char read_write, u8 command, int size, |
1da177e4 LT |
1777 | union i2c_smbus_data * data) |
1778 | { | |
1779 | /* So we need to generate a series of msgs. In the case of writing, we | |
1780 | need to use only one message; when reading, we need two. We initialize | |
1781 | most things with sane defaults, to keep the code below somewhat | |
1782 | simpler. */ | |
5c50d188 HI |
1783 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1784 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1785 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1786 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1787 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1788 | }; | |
1789 | int i; | |
421ef47b | 1790 | u8 partial_pec = 0; |
24a5bb7b | 1791 | int status; |
1da177e4 LT |
1792 | |
1793 | msgbuf0[0] = command; | |
1794 | switch(size) { | |
1795 | case I2C_SMBUS_QUICK: | |
1796 | msg[0].len = 0; | |
1797 | /* Special case: The read/write field is used as data */ | |
1798 | msg[0].flags = flags | (read_write==I2C_SMBUS_READ)?I2C_M_RD:0; | |
1799 | num = 1; | |
1800 | break; | |
1801 | case I2C_SMBUS_BYTE: | |
1802 | if (read_write == I2C_SMBUS_READ) { | |
1803 | /* Special case: only a read! */ | |
1804 | msg[0].flags = I2C_M_RD | flags; | |
1805 | num = 1; | |
1806 | } | |
1807 | break; | |
1808 | case I2C_SMBUS_BYTE_DATA: | |
1809 | if (read_write == I2C_SMBUS_READ) | |
1810 | msg[1].len = 1; | |
1811 | else { | |
1812 | msg[0].len = 2; | |
1813 | msgbuf0[1] = data->byte; | |
1814 | } | |
1815 | break; | |
1816 | case I2C_SMBUS_WORD_DATA: | |
1817 | if (read_write == I2C_SMBUS_READ) | |
1818 | msg[1].len = 2; | |
1819 | else { | |
1820 | msg[0].len=3; | |
1821 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1822 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1823 | } |
1824 | break; | |
1825 | case I2C_SMBUS_PROC_CALL: | |
1826 | num = 2; /* Special case */ | |
1827 | read_write = I2C_SMBUS_READ; | |
1828 | msg[0].len = 3; | |
1829 | msg[1].len = 2; | |
1830 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1831 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1832 | break; |
1833 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1834 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1835 | msg[1].flags |= I2C_M_RECV_LEN; |
1836 | msg[1].len = 1; /* block length will be added by | |
1837 | the underlying bus driver */ | |
1da177e4 LT |
1838 | } else { |
1839 | msg[0].len = data->block[0] + 2; | |
1840 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1841 | dev_err(&adapter->dev, |
1842 | "Invalid block write size %d\n", | |
1843 | data->block[0]); | |
1844 | return -EINVAL; | |
1da177e4 | 1845 | } |
5c50d188 | 1846 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1847 | msgbuf0[i] = data->block[i-1]; |
1848 | } | |
1849 | break; | |
1850 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1851 | num = 2; /* Another special case */ |
1852 | read_write = I2C_SMBUS_READ; | |
1853 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1854 | dev_err(&adapter->dev, |
1855 | "Invalid block write size %d\n", | |
209d27c3 | 1856 | data->block[0]); |
24a5bb7b | 1857 | return -EINVAL; |
209d27c3 JD |
1858 | } |
1859 | msg[0].len = data->block[0] + 2; | |
1860 | for (i = 1; i < msg[0].len; i++) | |
1861 | msgbuf0[i] = data->block[i-1]; | |
1862 | msg[1].flags |= I2C_M_RECV_LEN; | |
1863 | msg[1].len = 1; /* block length will be added by | |
1864 | the underlying bus driver */ | |
1865 | break; | |
1da177e4 LT |
1866 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1867 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1868 | msg[1].len = data->block[0]; |
1da177e4 LT |
1869 | } else { |
1870 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1871 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1872 | dev_err(&adapter->dev, |
1873 | "Invalid block write size %d\n", | |
1874 | data->block[0]); | |
1875 | return -EINVAL; | |
1da177e4 LT |
1876 | } |
1877 | for (i = 1; i <= data->block[0]; i++) | |
1878 | msgbuf0[i] = data->block[i]; | |
1879 | } | |
1880 | break; | |
1881 | default: | |
24a5bb7b DB |
1882 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1883 | return -EOPNOTSUPP; | |
1da177e4 LT |
1884 | } |
1885 | ||
421ef47b JD |
1886 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1887 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1888 | if (i) { | |
1889 | /* Compute PEC if first message is a write */ | |
1890 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1891 | if (num == 1) /* Write only */ |
421ef47b JD |
1892 | i2c_smbus_add_pec(&msg[0]); |
1893 | else /* Write followed by read */ | |
1894 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1895 | } | |
1896 | /* Ask for PEC if last message is a read */ | |
1897 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1898 | msg[num-1].len++; |
421ef47b JD |
1899 | } |
1900 | ||
24a5bb7b DB |
1901 | status = i2c_transfer(adapter, msg, num); |
1902 | if (status < 0) | |
1903 | return status; | |
1da177e4 | 1904 | |
421ef47b JD |
1905 | /* Check PEC if last message is a read */ |
1906 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1907 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1908 | if (status < 0) | |
1909 | return status; | |
421ef47b JD |
1910 | } |
1911 | ||
1da177e4 LT |
1912 | if (read_write == I2C_SMBUS_READ) |
1913 | switch(size) { | |
1914 | case I2C_SMBUS_BYTE: | |
1915 | data->byte = msgbuf0[0]; | |
1916 | break; | |
1917 | case I2C_SMBUS_BYTE_DATA: | |
1918 | data->byte = msgbuf1[0]; | |
1919 | break; | |
438d6c2c | 1920 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1921 | case I2C_SMBUS_PROC_CALL: |
1922 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1923 | break; | |
1924 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1925 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1926 | data->block[i+1] = msgbuf1[i]; |
1927 | break; | |
209d27c3 JD |
1928 | case I2C_SMBUS_BLOCK_DATA: |
1929 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1930 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1931 | data->block[i] = msgbuf1[i]; | |
1932 | break; | |
1da177e4 LT |
1933 | } |
1934 | return 0; | |
1935 | } | |
1936 | ||
a1cdedac DB |
1937 | /** |
1938 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1939 | * @adapter: Handle to I2C bus | |
1940 | * @addr: Address of SMBus slave on that bus | |
1941 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1942 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1943 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1944 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1945 | * @data: Data to be read or written | |
1946 | * | |
1947 | * This executes an SMBus protocol operation, and returns a negative | |
1948 | * errno code else zero on success. | |
1949 | */ | |
1da177e4 | 1950 | s32 i2c_smbus_xfer(struct i2c_adapter * adapter, u16 addr, unsigned short flags, |
a1cdedac | 1951 | char read_write, u8 command, int protocol, |
1da177e4 LT |
1952 | union i2c_smbus_data * data) |
1953 | { | |
1954 | s32 res; | |
1da177e4 LT |
1955 | |
1956 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1957 | |
1958 | if (adapter->algo->smbus_xfer) { | |
5c085d36 | 1959 | mutex_lock(&adapter->bus_lock); |
1da177e4 | 1960 | res = adapter->algo->smbus_xfer(adapter,addr,flags,read_write, |
a1cdedac | 1961 | command, protocol, data); |
5c085d36 | 1962 | mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1963 | } else |
1964 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1965 | command, protocol, data); |
1da177e4 | 1966 | |
1da177e4 LT |
1967 | return res; |
1968 | } | |
1da177e4 | 1969 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1970 | |
1971 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1972 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1973 | MODULE_LICENSE("GPL"); |