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