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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> | |
b3585e4f | 32 | #include <linux/mutex.h> |
b8d6f45b | 33 | #include <linux/completion.h> |
cea443a8 MR |
34 | #include <linux/hardirq.h> |
35 | #include <linux/irqflags.h> | |
f18c41da | 36 | #include <linux/rwsem.h> |
1da177e4 LT |
37 | #include <asm/uaccess.h> |
38 | ||
9c1600ed DB |
39 | #include "i2c-core.h" |
40 | ||
1da177e4 | 41 | |
99cd8e25 | 42 | /* core_lock protects i2c_adapter_idr, userspace_devices, and guarantees |
35fc37f8 JD |
43 | that device detection, deletion of detected devices, and attach_adapter |
44 | and detach_adapter calls are serialized */ | |
caada32a | 45 | static DEFINE_MUTEX(core_lock); |
1da177e4 | 46 | static DEFINE_IDR(i2c_adapter_idr); |
99cd8e25 | 47 | static LIST_HEAD(userspace_devices); |
1da177e4 | 48 | |
4f8cf824 | 49 | static struct device_type i2c_client_type; |
f8a227e8 | 50 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr); |
4735c98f | 51 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
52 | |
53 | /* ------------------------------------------------------------------------- */ | |
54 | ||
d2653e92 JD |
55 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
56 | const struct i2c_client *client) | |
57 | { | |
58 | while (id->name[0]) { | |
59 | if (strcmp(client->name, id->name) == 0) | |
60 | return id; | |
61 | id++; | |
62 | } | |
63 | return NULL; | |
64 | } | |
65 | ||
1da177e4 LT |
66 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
67 | { | |
51298d12 JD |
68 | struct i2c_client *client = i2c_verify_client(dev); |
69 | struct i2c_driver *driver; | |
70 | ||
71 | if (!client) | |
72 | return 0; | |
7b4fbc50 | 73 | |
51298d12 | 74 | driver = to_i2c_driver(drv); |
d2653e92 JD |
75 | /* match on an id table if there is one */ |
76 | if (driver->id_table) | |
77 | return i2c_match_id(driver->id_table, client) != NULL; | |
78 | ||
eb8a7908 | 79 | return 0; |
1da177e4 LT |
80 | } |
81 | ||
7b4fbc50 DB |
82 | #ifdef CONFIG_HOTPLUG |
83 | ||
84 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 85 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
86 | { |
87 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 88 | |
eb8a7908 JD |
89 | if (add_uevent_var(env, "MODALIAS=%s%s", |
90 | I2C_MODULE_PREFIX, client->name)) | |
91 | return -ENOMEM; | |
7b4fbc50 DB |
92 | dev_dbg(dev, "uevent\n"); |
93 | return 0; | |
94 | } | |
95 | ||
96 | #else | |
97 | #define i2c_device_uevent NULL | |
98 | #endif /* CONFIG_HOTPLUG */ | |
99 | ||
f37dd80a | 100 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 101 | { |
51298d12 JD |
102 | struct i2c_client *client = i2c_verify_client(dev); |
103 | struct i2c_driver *driver; | |
50c3304a | 104 | int status; |
7b4fbc50 | 105 | |
51298d12 JD |
106 | if (!client) |
107 | return 0; | |
108 | ||
109 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 110 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
111 | return -ENODEV; |
112 | client->driver = driver; | |
ee35425c MP |
113 | if (!device_can_wakeup(&client->dev)) |
114 | device_init_wakeup(&client->dev, | |
115 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 116 | dev_dbg(dev, "probe\n"); |
d2653e92 | 117 | |
e0457442 | 118 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
119 | if (status) |
120 | client->driver = NULL; | |
121 | return status; | |
f37dd80a | 122 | } |
1da177e4 | 123 | |
f37dd80a DB |
124 | static int i2c_device_remove(struct device *dev) |
125 | { | |
51298d12 | 126 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
127 | struct i2c_driver *driver; |
128 | int status; | |
129 | ||
51298d12 | 130 | if (!client || !dev->driver) |
a1d9e6e4 DB |
131 | return 0; |
132 | ||
133 | driver = to_i2c_driver(dev->driver); | |
134 | if (driver->remove) { | |
135 | dev_dbg(dev, "remove\n"); | |
136 | status = driver->remove(client); | |
137 | } else { | |
138 | dev->driver = NULL; | |
139 | status = 0; | |
140 | } | |
141 | if (status == 0) | |
142 | client->driver = NULL; | |
143 | return status; | |
1da177e4 LT |
144 | } |
145 | ||
f37dd80a | 146 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 147 | { |
51298d12 | 148 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
149 | struct i2c_driver *driver; |
150 | ||
51298d12 | 151 | if (!client || !dev->driver) |
f37dd80a DB |
152 | return; |
153 | driver = to_i2c_driver(dev->driver); | |
154 | if (driver->shutdown) | |
51298d12 | 155 | driver->shutdown(client); |
1da177e4 LT |
156 | } |
157 | ||
09b8ce0a | 158 | static int i2c_device_suspend(struct device *dev, pm_message_t mesg) |
1da177e4 | 159 | { |
51298d12 | 160 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
161 | struct i2c_driver *driver; |
162 | ||
51298d12 | 163 | if (!client || !dev->driver) |
f37dd80a DB |
164 | return 0; |
165 | driver = to_i2c_driver(dev->driver); | |
166 | if (!driver->suspend) | |
167 | return 0; | |
51298d12 | 168 | return driver->suspend(client, mesg); |
1da177e4 LT |
169 | } |
170 | ||
09b8ce0a | 171 | static int i2c_device_resume(struct device *dev) |
1da177e4 | 172 | { |
51298d12 | 173 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
174 | struct i2c_driver *driver; |
175 | ||
51298d12 | 176 | if (!client || !dev->driver) |
f37dd80a DB |
177 | return 0; |
178 | driver = to_i2c_driver(dev->driver); | |
179 | if (!driver->resume) | |
180 | return 0; | |
51298d12 | 181 | return driver->resume(client); |
1da177e4 LT |
182 | } |
183 | ||
9c1600ed DB |
184 | static void i2c_client_dev_release(struct device *dev) |
185 | { | |
186 | kfree(to_i2c_client(dev)); | |
187 | } | |
188 | ||
09b8ce0a | 189 | static ssize_t |
4f8cf824 | 190 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 191 | { |
4f8cf824 JD |
192 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
193 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
194 | } |
195 | ||
09b8ce0a ZX |
196 | static ssize_t |
197 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
198 | { |
199 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 200 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
201 | } |
202 | ||
4f8cf824 | 203 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
204 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
205 | ||
206 | static struct attribute *i2c_dev_attrs[] = { | |
207 | &dev_attr_name.attr, | |
7b4fbc50 | 208 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
209 | &dev_attr_modalias.attr, |
210 | NULL | |
211 | }; | |
212 | ||
213 | static struct attribute_group i2c_dev_attr_group = { | |
214 | .attrs = i2c_dev_attrs, | |
215 | }; | |
216 | ||
217 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
218 | &i2c_dev_attr_group, | |
219 | NULL | |
7b4fbc50 DB |
220 | }; |
221 | ||
e9ca9eb9 | 222 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
223 | .name = "i2c", |
224 | .match = i2c_device_match, | |
225 | .probe = i2c_device_probe, | |
226 | .remove = i2c_device_remove, | |
227 | .shutdown = i2c_device_shutdown, | |
228 | .suspend = i2c_device_suspend, | |
229 | .resume = i2c_device_resume, | |
b864c7d5 | 230 | }; |
e9ca9eb9 | 231 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 232 | |
51298d12 JD |
233 | static struct device_type i2c_client_type = { |
234 | .groups = i2c_dev_attr_groups, | |
235 | .uevent = i2c_device_uevent, | |
236 | .release = i2c_client_dev_release, | |
237 | }; | |
238 | ||
9b766b81 DB |
239 | |
240 | /** | |
241 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
242 | * @dev: device, probably from some driver model iterator | |
243 | * | |
244 | * When traversing the driver model tree, perhaps using driver model | |
245 | * iterators like @device_for_each_child(), you can't assume very much | |
246 | * about the nodes you find. Use this function to avoid oopses caused | |
247 | * by wrongly treating some non-I2C device as an i2c_client. | |
248 | */ | |
249 | struct i2c_client *i2c_verify_client(struct device *dev) | |
250 | { | |
51298d12 | 251 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
252 | ? to_i2c_client(dev) |
253 | : NULL; | |
254 | } | |
255 | EXPORT_SYMBOL(i2c_verify_client); | |
256 | ||
257 | ||
9c1600ed | 258 | /** |
f8a227e8 | 259 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
260 | * @adap: the adapter managing the device |
261 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 262 | * Context: can sleep |
9c1600ed | 263 | * |
f8a227e8 JD |
264 | * Create an i2c device. Binding is handled through driver model |
265 | * probe()/remove() methods. A driver may be bound to this device when we | |
266 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
267 | * load the driver module). This call is not appropriate for use by mainboard | |
268 | * initialization logic, which usually runs during an arch_initcall() long | |
269 | * before any i2c_adapter could exist. | |
9c1600ed DB |
270 | * |
271 | * This returns the new i2c client, which may be saved for later use with | |
272 | * i2c_unregister_device(); or NULL to indicate an error. | |
273 | */ | |
274 | struct i2c_client * | |
275 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
276 | { | |
277 | struct i2c_client *client; | |
278 | int status; | |
279 | ||
280 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
281 | if (!client) | |
282 | return NULL; | |
283 | ||
284 | client->adapter = adap; | |
285 | ||
286 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 287 | |
11f1f2af AV |
288 | if (info->archdata) |
289 | client->dev.archdata = *info->archdata; | |
290 | ||
ee35425c | 291 | client->flags = info->flags; |
9c1600ed DB |
292 | client->addr = info->addr; |
293 | client->irq = info->irq; | |
294 | ||
9c1600ed DB |
295 | strlcpy(client->name, info->type, sizeof(client->name)); |
296 | ||
f8a227e8 JD |
297 | /* Check for address business */ |
298 | status = i2c_check_addr(adap, client->addr); | |
299 | if (status) | |
300 | goto out_err; | |
301 | ||
302 | client->dev.parent = &client->adapter->dev; | |
303 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 304 | client->dev.type = &i2c_client_type; |
f8a227e8 JD |
305 | |
306 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
307 | client->addr); | |
308 | status = device_register(&client->dev); | |
309 | if (status) | |
310 | goto out_err; | |
311 | ||
f8a227e8 JD |
312 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
313 | client->name, dev_name(&client->dev)); | |
314 | ||
9c1600ed | 315 | return client; |
f8a227e8 JD |
316 | |
317 | out_err: | |
318 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
319 | "(%d)\n", client->name, client->addr, status); | |
320 | kfree(client); | |
321 | return NULL; | |
9c1600ed DB |
322 | } |
323 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
324 | ||
325 | ||
326 | /** | |
327 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
328 | * @client: value returned from i2c_new_device() | |
d64f73be | 329 | * Context: can sleep |
9c1600ed DB |
330 | */ |
331 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 332 | { |
a1d9e6e4 DB |
333 | device_unregister(&client->dev); |
334 | } | |
9c1600ed | 335 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
336 | |
337 | ||
60b129d7 JD |
338 | static const struct i2c_device_id dummy_id[] = { |
339 | { "dummy", 0 }, | |
340 | { }, | |
341 | }; | |
342 | ||
d2653e92 JD |
343 | static int dummy_probe(struct i2c_client *client, |
344 | const struct i2c_device_id *id) | |
345 | { | |
346 | return 0; | |
347 | } | |
348 | ||
349 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
350 | { |
351 | return 0; | |
352 | } | |
353 | ||
354 | static struct i2c_driver dummy_driver = { | |
355 | .driver.name = "dummy", | |
d2653e92 JD |
356 | .probe = dummy_probe, |
357 | .remove = dummy_remove, | |
60b129d7 | 358 | .id_table = dummy_id, |
e9f1373b DB |
359 | }; |
360 | ||
361 | /** | |
362 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
363 | * @adapter: the adapter managing the device | |
364 | * @address: seven bit address to be used | |
e9f1373b DB |
365 | * Context: can sleep |
366 | * | |
367 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
368 | * with devices that consume multiple addresses. Examples of such chips | |
369 | * include various EEPROMS (like 24c04 and 24c08 models). | |
370 | * | |
371 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
372 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
373 | * And second, this prevents the specified address from being bound to a | |
374 | * different driver. | |
375 | * | |
376 | * This returns the new i2c client, which should be saved for later use with | |
377 | * i2c_unregister_device(); or NULL to indicate an error. | |
378 | */ | |
09b8ce0a | 379 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
380 | { |
381 | struct i2c_board_info info = { | |
60b129d7 | 382 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
383 | }; |
384 | ||
e9f1373b DB |
385 | return i2c_new_device(adapter, &info); |
386 | } | |
387 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
388 | ||
f37dd80a DB |
389 | /* ------------------------------------------------------------------------- */ |
390 | ||
16ffadfc DB |
391 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
392 | ||
83eaaed0 | 393 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 394 | { |
ef2c8321 | 395 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
396 | complete(&adap->dev_released); |
397 | } | |
398 | ||
99cd8e25 JD |
399 | /* |
400 | * Let users instantiate I2C devices through sysfs. This can be used when | |
401 | * platform initialization code doesn't contain the proper data for | |
402 | * whatever reason. Also useful for drivers that do device detection and | |
403 | * detection fails, either because the device uses an unexpected address, | |
404 | * or this is a compatible device with different ID register values. | |
405 | * | |
406 | * Parameter checking may look overzealous, but we really don't want | |
407 | * the user to provide incorrect parameters. | |
408 | */ | |
409 | static ssize_t | |
410 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
411 | const char *buf, size_t count) | |
412 | { | |
413 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
414 | struct i2c_board_info info; | |
415 | struct i2c_client *client; | |
416 | char *blank, end; | |
417 | int res; | |
418 | ||
419 | dev_warn(dev, "The new_device interface is still experimental " | |
420 | "and may change in a near future\n"); | |
421 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
422 | ||
423 | blank = strchr(buf, ' '); | |
424 | if (!blank) { | |
425 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
426 | return -EINVAL; | |
427 | } | |
428 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
429 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
430 | return -EINVAL; | |
431 | } | |
432 | memcpy(info.type, buf, blank - buf); | |
433 | ||
434 | /* Parse remaining parameters, reject extra parameters */ | |
435 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
436 | if (res < 1) { | |
437 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
438 | return -EINVAL; | |
439 | } | |
440 | if (res > 1 && end != '\n') { | |
441 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
442 | return -EINVAL; | |
443 | } | |
444 | ||
445 | if (info.addr < 0x03 || info.addr > 0x77) { | |
446 | dev_err(dev, "%s: Invalid I2C address 0x%hx\n", "new_device", | |
447 | info.addr); | |
448 | return -EINVAL; | |
449 | } | |
450 | ||
451 | client = i2c_new_device(adap, &info); | |
452 | if (!client) | |
453 | return -EEXIST; | |
454 | ||
455 | /* Keep track of the added device */ | |
456 | mutex_lock(&core_lock); | |
457 | list_add_tail(&client->detected, &userspace_devices); | |
458 | mutex_unlock(&core_lock); | |
459 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", | |
460 | info.type, info.addr); | |
461 | ||
462 | return count; | |
463 | } | |
464 | ||
465 | /* | |
466 | * And of course let the users delete the devices they instantiated, if | |
467 | * they got it wrong. This interface can only be used to delete devices | |
468 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
469 | * don't delete devices to which some kernel code still has references. | |
470 | * | |
471 | * Parameter checking may look overzealous, but we really don't want | |
472 | * the user to delete the wrong device. | |
473 | */ | |
474 | static ssize_t | |
475 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
476 | const char *buf, size_t count) | |
477 | { | |
478 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
479 | struct i2c_client *client, *next; | |
480 | unsigned short addr; | |
481 | char end; | |
482 | int res; | |
483 | ||
484 | /* Parse parameters, reject extra parameters */ | |
485 | res = sscanf(buf, "%hi%c", &addr, &end); | |
486 | if (res < 1) { | |
487 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
488 | return -EINVAL; | |
489 | } | |
490 | if (res > 1 && end != '\n') { | |
491 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
492 | return -EINVAL; | |
493 | } | |
494 | ||
495 | /* Make sure the device was added through sysfs */ | |
496 | res = -ENOENT; | |
497 | mutex_lock(&core_lock); | |
498 | list_for_each_entry_safe(client, next, &userspace_devices, detected) { | |
499 | if (client->addr == addr && client->adapter == adap) { | |
500 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", | |
501 | "delete_device", client->name, client->addr); | |
502 | ||
503 | list_del(&client->detected); | |
504 | i2c_unregister_device(client); | |
505 | res = count; | |
506 | break; | |
507 | } | |
508 | } | |
509 | mutex_unlock(&core_lock); | |
510 | ||
511 | if (res < 0) | |
512 | dev_err(dev, "%s: Can't find device in list\n", | |
513 | "delete_device"); | |
514 | return res; | |
515 | } | |
516 | ||
4f8cf824 JD |
517 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
518 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
519 | ||
520 | static struct attribute *i2c_adapter_attrs[] = { | |
521 | &dev_attr_name.attr, | |
522 | &dev_attr_new_device.attr, | |
523 | &dev_attr_delete_device.attr, | |
524 | NULL | |
525 | }; | |
526 | ||
527 | static struct attribute_group i2c_adapter_attr_group = { | |
528 | .attrs = i2c_adapter_attrs, | |
529 | }; | |
530 | ||
531 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
532 | &i2c_adapter_attr_group, | |
533 | NULL | |
16ffadfc | 534 | }; |
b119dc3f | 535 | |
4f8cf824 JD |
536 | static struct device_type i2c_adapter_type = { |
537 | .groups = i2c_adapter_attr_groups, | |
538 | .release = i2c_adapter_dev_release, | |
1da177e4 LT |
539 | }; |
540 | ||
2bb5095a JD |
541 | #ifdef CONFIG_I2C_COMPAT |
542 | static struct class_compat *i2c_adapter_compat_class; | |
543 | #endif | |
544 | ||
9c1600ed DB |
545 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
546 | { | |
547 | struct i2c_devinfo *devinfo; | |
548 | ||
f18c41da | 549 | down_read(&__i2c_board_lock); |
9c1600ed DB |
550 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
551 | if (devinfo->busnum == adapter->nr | |
552 | && !i2c_new_device(adapter, | |
553 | &devinfo->board_info)) | |
09b8ce0a ZX |
554 | dev_err(&adapter->dev, |
555 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
556 | devinfo->board_info.addr); |
557 | } | |
f18c41da | 558 | up_read(&__i2c_board_lock); |
9c1600ed DB |
559 | } |
560 | ||
026526f5 JD |
561 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
562 | { | |
563 | struct i2c_driver *driver = to_i2c_driver(d); | |
564 | struct i2c_adapter *adap = data; | |
565 | ||
4735c98f JD |
566 | /* Detect supported devices on that bus, and instantiate them */ |
567 | i2c_detect(adap, driver); | |
568 | ||
569 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
570 | if (driver->attach_adapter) { |
571 | /* We ignore the return code; if it fails, too bad */ | |
572 | driver->attach_adapter(adap); | |
573 | } | |
574 | return 0; | |
575 | } | |
576 | ||
6e13e641 | 577 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 578 | { |
026526f5 | 579 | int res = 0, dummy; |
1da177e4 | 580 | |
1d0b19c9 | 581 | /* Can't register until after driver model init */ |
35fc37f8 JD |
582 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
583 | res = -EAGAIN; | |
584 | goto out_list; | |
585 | } | |
1d0b19c9 | 586 | |
194684e5 | 587 | rt_mutex_init(&adap->bus_lock); |
1da177e4 | 588 | |
8fcfef6e JD |
589 | /* Set default timeout to 1 second if not already set */ |
590 | if (adap->timeout == 0) | |
591 | adap->timeout = HZ; | |
592 | ||
27d9c183 | 593 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
594 | adap->dev.bus = &i2c_bus_type; |
595 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
596 | res = device_register(&adap->dev); |
597 | if (res) | |
598 | goto out_list; | |
1da177e4 | 599 | |
b6d7b3d1 JD |
600 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
601 | ||
2bb5095a JD |
602 | #ifdef CONFIG_I2C_COMPAT |
603 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
604 | adap->dev.parent); | |
605 | if (res) | |
606 | dev_warn(&adap->dev, | |
607 | "Failed to create compatibility class link\n"); | |
608 | #endif | |
609 | ||
729d6dd5 | 610 | /* create pre-declared device nodes */ |
6e13e641 DB |
611 | if (adap->nr < __i2c_first_dynamic_bus_num) |
612 | i2c_scan_static_board_info(adap); | |
613 | ||
4735c98f | 614 | /* Notify drivers */ |
35fc37f8 | 615 | mutex_lock(&core_lock); |
026526f5 JD |
616 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
617 | i2c_do_add_adapter); | |
caada32a | 618 | mutex_unlock(&core_lock); |
35fc37f8 JD |
619 | |
620 | return 0; | |
b119c6c9 | 621 | |
b119c6c9 | 622 | out_list: |
35fc37f8 | 623 | mutex_lock(&core_lock); |
b119c6c9 | 624 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
625 | mutex_unlock(&core_lock); |
626 | return res; | |
1da177e4 LT |
627 | } |
628 | ||
6e13e641 DB |
629 | /** |
630 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
631 | * @adapter: the adapter to add | |
d64f73be | 632 | * Context: can sleep |
6e13e641 DB |
633 | * |
634 | * This routine is used to declare an I2C adapter when its bus number | |
635 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
636 | * USB links or PCI plugin cards. | |
637 | * | |
638 | * When this returns zero, a new bus number was allocated and stored | |
639 | * in adap->nr, and the specified adapter became available for clients. | |
640 | * Otherwise, a negative errno value is returned. | |
641 | */ | |
642 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
643 | { | |
644 | int id, res = 0; | |
645 | ||
646 | retry: | |
647 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
648 | return -ENOMEM; | |
649 | ||
caada32a | 650 | mutex_lock(&core_lock); |
6e13e641 DB |
651 | /* "above" here means "above or equal to", sigh */ |
652 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
653 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 654 | mutex_unlock(&core_lock); |
6e13e641 DB |
655 | |
656 | if (res < 0) { | |
657 | if (res == -EAGAIN) | |
658 | goto retry; | |
659 | return res; | |
660 | } | |
661 | ||
662 | adapter->nr = id; | |
663 | return i2c_register_adapter(adapter); | |
664 | } | |
665 | EXPORT_SYMBOL(i2c_add_adapter); | |
666 | ||
667 | /** | |
668 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
669 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 670 | * Context: can sleep |
6e13e641 DB |
671 | * |
672 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
673 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
674 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
675 | * is used to properly configure I2C devices. |
676 | * | |
677 | * If no devices have pre-been declared for this bus, then be sure to | |
678 | * register the adapter before any dynamically allocated ones. Otherwise | |
679 | * the required bus ID may not be available. | |
680 | * | |
681 | * When this returns zero, the specified adapter became available for | |
682 | * clients using the bus number provided in adap->nr. Also, the table | |
683 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
684 | * and the appropriate driver model device nodes are created. Otherwise, a | |
685 | * negative errno value is returned. | |
686 | */ | |
687 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
688 | { | |
689 | int id; | |
690 | int status; | |
691 | ||
692 | if (adap->nr & ~MAX_ID_MASK) | |
693 | return -EINVAL; | |
694 | ||
695 | retry: | |
696 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
697 | return -ENOMEM; | |
698 | ||
caada32a | 699 | mutex_lock(&core_lock); |
6e13e641 DB |
700 | /* "above" here means "above or equal to", sigh; |
701 | * we need the "equal to" result to force the result | |
702 | */ | |
703 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
704 | if (status == 0 && id != adap->nr) { | |
705 | status = -EBUSY; | |
706 | idr_remove(&i2c_adapter_idr, id); | |
707 | } | |
caada32a | 708 | mutex_unlock(&core_lock); |
6e13e641 DB |
709 | if (status == -EAGAIN) |
710 | goto retry; | |
711 | ||
712 | if (status == 0) | |
713 | status = i2c_register_adapter(adap); | |
714 | return status; | |
715 | } | |
716 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
717 | ||
026526f5 JD |
718 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
719 | { | |
720 | struct i2c_driver *driver = to_i2c_driver(d); | |
721 | struct i2c_adapter *adapter = data; | |
4735c98f | 722 | struct i2c_client *client, *_n; |
026526f5 JD |
723 | int res; |
724 | ||
acec211c JD |
725 | /* Remove the devices we created ourselves as the result of hardware |
726 | * probing (using a driver's detect method) */ | |
4735c98f JD |
727 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
728 | if (client->adapter == adapter) { | |
729 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
730 | client->name, client->addr); | |
731 | list_del(&client->detected); | |
732 | i2c_unregister_device(client); | |
733 | } | |
734 | } | |
735 | ||
026526f5 JD |
736 | if (!driver->detach_adapter) |
737 | return 0; | |
738 | res = driver->detach_adapter(adapter); | |
739 | if (res) | |
740 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
741 | "for driver [%s]\n", res, driver->driver.name); | |
742 | return res; | |
743 | } | |
744 | ||
e549c2b5 JD |
745 | static int __unregister_client(struct device *dev, void *dummy) |
746 | { | |
747 | struct i2c_client *client = i2c_verify_client(dev); | |
748 | if (client) | |
749 | i2c_unregister_device(client); | |
750 | return 0; | |
751 | } | |
752 | ||
d64f73be DB |
753 | /** |
754 | * i2c_del_adapter - unregister I2C adapter | |
755 | * @adap: the adapter being unregistered | |
756 | * Context: can sleep | |
757 | * | |
758 | * This unregisters an I2C adapter which was previously registered | |
759 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
760 | */ | |
1da177e4 LT |
761 | int i2c_del_adapter(struct i2c_adapter *adap) |
762 | { | |
1da177e4 | 763 | int res = 0; |
35fc37f8 | 764 | struct i2c_adapter *found; |
bbd2d9c9 | 765 | struct i2c_client *client, *next; |
1da177e4 LT |
766 | |
767 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
768 | mutex_lock(&core_lock); |
769 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
770 | mutex_unlock(&core_lock); | |
771 | if (found != adap) { | |
b6d7b3d1 JD |
772 | pr_debug("i2c-core: attempting to delete unregistered " |
773 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 774 | return -EINVAL; |
1da177e4 LT |
775 | } |
776 | ||
026526f5 | 777 | /* Tell drivers about this removal */ |
35fc37f8 | 778 | mutex_lock(&core_lock); |
026526f5 JD |
779 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
780 | i2c_do_del_adapter); | |
35fc37f8 | 781 | mutex_unlock(&core_lock); |
026526f5 | 782 | if (res) |
35fc37f8 | 783 | return res; |
1da177e4 | 784 | |
bbd2d9c9 JD |
785 | /* Remove devices instantiated from sysfs */ |
786 | list_for_each_entry_safe(client, next, &userspace_devices, detected) { | |
787 | if (client->adapter == adap) { | |
788 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", | |
789 | client->name, client->addr); | |
790 | list_del(&client->detected); | |
791 | i2c_unregister_device(client); | |
792 | } | |
793 | } | |
794 | ||
e549c2b5 JD |
795 | /* Detach any active clients. This can't fail, thus we do not |
796 | checking the returned value. */ | |
797 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 | 798 | |
2bb5095a JD |
799 | #ifdef CONFIG_I2C_COMPAT |
800 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
801 | adap->dev.parent); | |
802 | #endif | |
803 | ||
1da177e4 LT |
804 | /* clean up the sysfs representation */ |
805 | init_completion(&adap->dev_released); | |
1da177e4 | 806 | device_unregister(&adap->dev); |
1da177e4 LT |
807 | |
808 | /* wait for sysfs to drop all references */ | |
809 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 810 | |
6e13e641 | 811 | /* free bus id */ |
35fc37f8 | 812 | mutex_lock(&core_lock); |
1da177e4 | 813 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 814 | mutex_unlock(&core_lock); |
1da177e4 | 815 | |
b6d7b3d1 | 816 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 | 817 | |
bd4bc3db JD |
818 | /* Clear the device structure in case this adapter is ever going to be |
819 | added again */ | |
820 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
821 | ||
35fc37f8 | 822 | return 0; |
1da177e4 | 823 | } |
c0564606 | 824 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
825 | |
826 | ||
7b4fbc50 DB |
827 | /* ------------------------------------------------------------------------- */ |
828 | ||
7f101a97 DY |
829 | static int __attach_adapter(struct device *dev, void *data) |
830 | { | |
4f8cf824 | 831 | struct i2c_adapter *adapter; |
7f101a97 DY |
832 | struct i2c_driver *driver = data; |
833 | ||
4f8cf824 JD |
834 | if (dev->type != &i2c_adapter_type) |
835 | return 0; | |
836 | adapter = to_i2c_adapter(dev); | |
837 | ||
4735c98f JD |
838 | i2c_detect(adapter, driver); |
839 | ||
840 | /* Legacy drivers scan i2c busses directly */ | |
841 | if (driver->attach_adapter) | |
842 | driver->attach_adapter(adapter); | |
7f101a97 DY |
843 | |
844 | return 0; | |
845 | } | |
846 | ||
7b4fbc50 DB |
847 | /* |
848 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 849 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
850 | */ |
851 | ||
de59cf9e | 852 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 853 | { |
7eebcb7c | 854 | int res; |
1da177e4 | 855 | |
1d0b19c9 DB |
856 | /* Can't register until after driver model init */ |
857 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
858 | return -EAGAIN; | |
859 | ||
1da177e4 | 860 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 861 | driver->driver.owner = owner; |
1da177e4 | 862 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 863 | |
729d6dd5 | 864 | /* When registration returns, the driver core |
6e13e641 DB |
865 | * will have called probe() for all matching-but-unbound devices. |
866 | */ | |
1da177e4 LT |
867 | res = driver_register(&driver->driver); |
868 | if (res) | |
7eebcb7c | 869 | return res; |
438d6c2c | 870 | |
35d8b2e6 | 871 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 872 | |
4735c98f JD |
873 | INIT_LIST_HEAD(&driver->clients); |
874 | /* Walk the adapters that are already present */ | |
35fc37f8 | 875 | mutex_lock(&core_lock); |
4f8cf824 | 876 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __attach_adapter); |
7f101a97 | 877 | mutex_unlock(&core_lock); |
35fc37f8 | 878 | |
7f101a97 DY |
879 | return 0; |
880 | } | |
881 | EXPORT_SYMBOL(i2c_register_driver); | |
882 | ||
883 | static int __detach_adapter(struct device *dev, void *data) | |
884 | { | |
4f8cf824 | 885 | struct i2c_adapter *adapter; |
7f101a97 | 886 | struct i2c_driver *driver = data; |
4735c98f JD |
887 | struct i2c_client *client, *_n; |
888 | ||
4f8cf824 JD |
889 | if (dev->type != &i2c_adapter_type) |
890 | return 0; | |
891 | adapter = to_i2c_adapter(dev); | |
892 | ||
acec211c JD |
893 | /* Remove the devices we created ourselves as the result of hardware |
894 | * probing (using a driver's detect method) */ | |
4735c98f JD |
895 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
896 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
897 | client->name, client->addr); | |
898 | list_del(&client->detected); | |
899 | i2c_unregister_device(client); | |
900 | } | |
901 | ||
7f101a97 DY |
902 | if (driver->detach_adapter) { |
903 | if (driver->detach_adapter(adapter)) | |
904 | dev_err(&adapter->dev, | |
905 | "detach_adapter failed for driver [%s]\n", | |
906 | driver->driver.name); | |
1da177e4 LT |
907 | } |
908 | ||
7eebcb7c | 909 | return 0; |
1da177e4 LT |
910 | } |
911 | ||
a1d9e6e4 DB |
912 | /** |
913 | * i2c_del_driver - unregister I2C driver | |
914 | * @driver: the driver being unregistered | |
d64f73be | 915 | * Context: can sleep |
a1d9e6e4 | 916 | */ |
b3e82096 | 917 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 918 | { |
caada32a | 919 | mutex_lock(&core_lock); |
4f8cf824 | 920 | bus_for_each_dev(&i2c_bus_type, NULL, driver, __detach_adapter); |
35fc37f8 | 921 | mutex_unlock(&core_lock); |
1da177e4 LT |
922 | |
923 | driver_unregister(&driver->driver); | |
35d8b2e6 | 924 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 925 | } |
c0564606 | 926 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 927 | |
7b4fbc50 DB |
928 | /* ------------------------------------------------------------------------- */ |
929 | ||
9b766b81 | 930 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 931 | { |
9b766b81 DB |
932 | struct i2c_client *client = i2c_verify_client(dev); |
933 | int addr = *(int *)addrp; | |
1da177e4 | 934 | |
9b766b81 DB |
935 | if (client && client->addr == addr) |
936 | return -EBUSY; | |
1da177e4 LT |
937 | return 0; |
938 | } | |
939 | ||
5e31c2bd | 940 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 941 | { |
9b766b81 | 942 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
943 | } |
944 | ||
e48d3319 JD |
945 | /** |
946 | * i2c_use_client - increments the reference count of the i2c client structure | |
947 | * @client: the client being referenced | |
948 | * | |
949 | * Each live reference to a client should be refcounted. The driver model does | |
950 | * that automatically as part of driver binding, so that most drivers don't | |
951 | * need to do this explicitly: they hold a reference until they're unbound | |
952 | * from the device. | |
953 | * | |
954 | * A pointer to the client with the incremented reference counter is returned. | |
955 | */ | |
956 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 957 | { |
6ea438ec DB |
958 | if (client && get_device(&client->dev)) |
959 | return client; | |
960 | return NULL; | |
1da177e4 | 961 | } |
c0564606 | 962 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 963 | |
e48d3319 JD |
964 | /** |
965 | * i2c_release_client - release a use of the i2c client structure | |
966 | * @client: the client being no longer referenced | |
967 | * | |
968 | * Must be called when a user of a client is finished with it. | |
969 | */ | |
970 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 971 | { |
6ea438ec DB |
972 | if (client) |
973 | put_device(&client->dev); | |
1da177e4 | 974 | } |
c0564606 | 975 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 976 | |
9b766b81 DB |
977 | struct i2c_cmd_arg { |
978 | unsigned cmd; | |
979 | void *arg; | |
980 | }; | |
981 | ||
982 | static int i2c_cmd(struct device *dev, void *_arg) | |
983 | { | |
984 | struct i2c_client *client = i2c_verify_client(dev); | |
985 | struct i2c_cmd_arg *arg = _arg; | |
986 | ||
987 | if (client && client->driver && client->driver->command) | |
988 | client->driver->command(client, arg->cmd, arg->arg); | |
989 | return 0; | |
990 | } | |
991 | ||
1da177e4 LT |
992 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
993 | { | |
9b766b81 | 994 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 995 | |
9b766b81 DB |
996 | cmd_arg.cmd = cmd; |
997 | cmd_arg.arg = arg; | |
998 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 999 | } |
c0564606 | 1000 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1001 | |
1002 | static int __init i2c_init(void) | |
1003 | { | |
1004 | int retval; | |
1005 | ||
1006 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1007 | if (retval) |
1008 | return retval; | |
2bb5095a JD |
1009 | #ifdef CONFIG_I2C_COMPAT |
1010 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1011 | if (!i2c_adapter_compat_class) { | |
1012 | retval = -ENOMEM; | |
1013 | goto bus_err; | |
1014 | } | |
1015 | #endif | |
e9f1373b DB |
1016 | retval = i2c_add_driver(&dummy_driver); |
1017 | if (retval) | |
2bb5095a | 1018 | goto class_err; |
e9f1373b DB |
1019 | return 0; |
1020 | ||
2bb5095a JD |
1021 | class_err: |
1022 | #ifdef CONFIG_I2C_COMPAT | |
1023 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1024 | bus_err: |
2bb5095a | 1025 | #endif |
e9f1373b DB |
1026 | bus_unregister(&i2c_bus_type); |
1027 | return retval; | |
1da177e4 LT |
1028 | } |
1029 | ||
1030 | static void __exit i2c_exit(void) | |
1031 | { | |
e9f1373b | 1032 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1033 | #ifdef CONFIG_I2C_COMPAT |
1034 | class_compat_unregister(i2c_adapter_compat_class); | |
1035 | #endif | |
1da177e4 LT |
1036 | bus_unregister(&i2c_bus_type); |
1037 | } | |
1038 | ||
a10f9e7c DB |
1039 | /* We must initialize early, because some subsystems register i2c drivers |
1040 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1041 | */ | |
1042 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1043 | module_exit(i2c_exit); |
1044 | ||
1045 | /* ---------------------------------------------------- | |
1046 | * the functional interface to the i2c busses. | |
1047 | * ---------------------------------------------------- | |
1048 | */ | |
1049 | ||
a1cdedac DB |
1050 | /** |
1051 | * i2c_transfer - execute a single or combined I2C message | |
1052 | * @adap: Handle to I2C bus | |
1053 | * @msgs: One or more messages to execute before STOP is issued to | |
1054 | * terminate the operation; each message begins with a START. | |
1055 | * @num: Number of messages to be executed. | |
1056 | * | |
1057 | * Returns negative errno, else the number of messages executed. | |
1058 | * | |
1059 | * Note that there is no requirement that each message be sent to | |
1060 | * the same slave address, although that is the most common model. | |
1061 | */ | |
09b8ce0a | 1062 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1063 | { |
66b650f0 CW |
1064 | unsigned long orig_jiffies; |
1065 | int ret, try; | |
1da177e4 | 1066 | |
a1cdedac DB |
1067 | /* REVISIT the fault reporting model here is weak: |
1068 | * | |
1069 | * - When we get an error after receiving N bytes from a slave, | |
1070 | * there is no way to report "N". | |
1071 | * | |
1072 | * - When we get a NAK after transmitting N bytes to a slave, | |
1073 | * there is no way to report "N" ... or to let the master | |
1074 | * continue executing the rest of this combined message, if | |
1075 | * that's the appropriate response. | |
1076 | * | |
1077 | * - When for example "num" is two and we successfully complete | |
1078 | * the first message but get an error part way through the | |
1079 | * second, it's unclear whether that should be reported as | |
1080 | * one (discarding status on the second message) or errno | |
1081 | * (discarding status on the first one). | |
1082 | */ | |
1083 | ||
1da177e4 LT |
1084 | if (adap->algo->master_xfer) { |
1085 | #ifdef DEBUG | |
1086 | for (ret = 0; ret < num; ret++) { | |
1087 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1088 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1089 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1090 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1091 | } |
1092 | #endif | |
1093 | ||
cea443a8 | 1094 | if (in_atomic() || irqs_disabled()) { |
194684e5 | 1095 | ret = rt_mutex_trylock(&adap->bus_lock); |
cea443a8 MR |
1096 | if (!ret) |
1097 | /* I2C activity is ongoing. */ | |
1098 | return -EAGAIN; | |
1099 | } else { | |
194684e5 | 1100 | rt_mutex_lock(&adap->bus_lock); |
cea443a8 MR |
1101 | } |
1102 | ||
66b650f0 CW |
1103 | /* Retry automatically on arbitration loss */ |
1104 | orig_jiffies = jiffies; | |
1105 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1106 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1107 | if (ret != -EAGAIN) | |
1108 | break; | |
1109 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1110 | break; | |
1111 | } | |
194684e5 | 1112 | rt_mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
1113 | |
1114 | return ret; | |
1115 | } else { | |
1116 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1117 | return -EOPNOTSUPP; |
1da177e4 LT |
1118 | } |
1119 | } | |
c0564606 | 1120 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1121 | |
a1cdedac DB |
1122 | /** |
1123 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1124 | * @client: Handle to slave device | |
1125 | * @buf: Data that will be written to the slave | |
1126 | * @count: How many bytes to write | |
1127 | * | |
1128 | * Returns negative errno, or else the number of bytes written. | |
1129 | */ | |
1da177e4 LT |
1130 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
1131 | { | |
1132 | int ret; | |
1133 | struct i2c_adapter *adap=client->adapter; | |
1134 | struct i2c_msg msg; | |
1135 | ||
815f55f2 JD |
1136 | msg.addr = client->addr; |
1137 | msg.flags = client->flags & I2C_M_TEN; | |
1138 | msg.len = count; | |
1139 | msg.buf = (char *)buf; | |
438d6c2c | 1140 | |
815f55f2 | 1141 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1142 | |
815f55f2 JD |
1143 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
1144 | transmitted, else error code. */ | |
1145 | return (ret == 1) ? count : ret; | |
1da177e4 | 1146 | } |
c0564606 | 1147 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1148 | |
a1cdedac DB |
1149 | /** |
1150 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1151 | * @client: Handle to slave device | |
1152 | * @buf: Where to store data read from slave | |
1153 | * @count: How many bytes to read | |
1154 | * | |
1155 | * Returns negative errno, or else the number of bytes read. | |
1156 | */ | |
1da177e4 LT |
1157 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
1158 | { | |
1159 | struct i2c_adapter *adap=client->adapter; | |
1160 | struct i2c_msg msg; | |
1161 | int ret; | |
815f55f2 JD |
1162 | |
1163 | msg.addr = client->addr; | |
1164 | msg.flags = client->flags & I2C_M_TEN; | |
1165 | msg.flags |= I2C_M_RD; | |
1166 | msg.len = count; | |
1167 | msg.buf = buf; | |
1168 | ||
1169 | ret = i2c_transfer(adap, &msg, 1); | |
1170 | ||
1171 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1172 | transmitted, else error code. */ | |
1173 | return (ret == 1) ? count : ret; | |
1da177e4 | 1174 | } |
c0564606 | 1175 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1176 | |
1da177e4 LT |
1177 | /* ---------------------------------------------------- |
1178 | * the i2c address scanning function | |
1179 | * Will not work for 10-bit addresses! | |
1180 | * ---------------------------------------------------- | |
1181 | */ | |
1da177e4 | 1182 | |
4735c98f JD |
1183 | static int i2c_detect_address(struct i2c_client *temp_client, int kind, |
1184 | struct i2c_driver *driver) | |
1185 | { | |
1186 | struct i2c_board_info info; | |
1187 | struct i2c_adapter *adapter = temp_client->adapter; | |
1188 | int addr = temp_client->addr; | |
1189 | int err; | |
1190 | ||
1191 | /* Make sure the address is valid */ | |
1192 | if (addr < 0x03 || addr > 0x77) { | |
1193 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
1194 | addr); | |
1195 | return -EINVAL; | |
1196 | } | |
1197 | ||
1198 | /* Skip if already in use */ | |
1199 | if (i2c_check_addr(adapter, addr)) | |
1200 | return 0; | |
1201 | ||
1202 | /* Make sure there is something at this address, unless forced */ | |
1203 | if (kind < 0) { | |
1204 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1205 | I2C_SMBUS_QUICK, NULL) < 0) | |
1206 | return 0; | |
1207 | ||
1208 | /* prevent 24RF08 corruption */ | |
1209 | if ((addr & ~0x0f) == 0x50) | |
1210 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1211 | I2C_SMBUS_QUICK, NULL); | |
1212 | } | |
1213 | ||
1214 | /* Finally call the custom detection function */ | |
1215 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1216 | info.addr = addr; | |
1217 | err = driver->detect(temp_client, kind, &info); | |
1218 | if (err) { | |
1219 | /* -ENODEV is returned if the detection fails. We catch it | |
1220 | here as this isn't an error. */ | |
1221 | return err == -ENODEV ? 0 : err; | |
1222 | } | |
1223 | ||
1224 | /* Consistency check */ | |
1225 | if (info.type[0] == '\0') { | |
1226 | dev_err(&adapter->dev, "%s detection function provided " | |
1227 | "no name for 0x%x\n", driver->driver.name, | |
1228 | addr); | |
1229 | } else { | |
1230 | struct i2c_client *client; | |
1231 | ||
1232 | /* Detection succeeded, instantiate the device */ | |
1233 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1234 | info.type, info.addr); | |
1235 | client = i2c_new_device(adapter, &info); | |
1236 | if (client) | |
1237 | list_add_tail(&client->detected, &driver->clients); | |
1238 | else | |
1239 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1240 | info.type, info.addr); | |
1241 | } | |
1242 | return 0; | |
1243 | } | |
1244 | ||
1245 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1246 | { | |
1247 | const struct i2c_client_address_data *address_data; | |
1248 | struct i2c_client *temp_client; | |
1249 | int i, err = 0; | |
1250 | int adap_id = i2c_adapter_id(adapter); | |
1251 | ||
1252 | address_data = driver->address_data; | |
1253 | if (!driver->detect || !address_data) | |
1254 | return 0; | |
1255 | ||
1256 | /* Set up a temporary client to help detect callback */ | |
1257 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1258 | if (!temp_client) | |
1259 | return -ENOMEM; | |
1260 | temp_client->adapter = adapter; | |
1261 | ||
4329cf86 JD |
1262 | /* Stop here if the classes do not match */ |
1263 | if (!(adapter->class & driver->class)) | |
1264 | goto exit_free; | |
1265 | ||
4735c98f JD |
1266 | /* Stop here if we can't use SMBUS_QUICK */ |
1267 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
c7b25a9e | 1268 | if (address_data->normal_i2c[0] == I2C_CLIENT_END) |
4735c98f JD |
1269 | goto exit_free; |
1270 | ||
1271 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1272 | "can't probe for chips\n"); | |
1273 | err = -EOPNOTSUPP; | |
1274 | goto exit_free; | |
1275 | } | |
1276 | ||
4735c98f | 1277 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { |
4735c98f JD |
1278 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
1279 | "addr 0x%02x\n", adap_id, | |
1280 | address_data->normal_i2c[i]); | |
1281 | temp_client->addr = address_data->normal_i2c[i]; | |
1282 | err = i2c_detect_address(temp_client, -1, driver); | |
1283 | if (err) | |
1284 | goto exit_free; | |
1285 | } | |
1286 | ||
1287 | exit_free: | |
1288 | kfree(temp_client); | |
1289 | return err; | |
1290 | } | |
1291 | ||
12b5053a JD |
1292 | struct i2c_client * |
1293 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1294 | struct i2c_board_info *info, | |
1295 | unsigned short const *addr_list) | |
1296 | { | |
1297 | int i; | |
1298 | ||
1299 | /* Stop here if the bus doesn't support probing */ | |
1300 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1301 | dev_err(&adap->dev, "Probing not supported\n"); | |
1302 | return NULL; | |
1303 | } | |
1304 | ||
12b5053a JD |
1305 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1306 | /* Check address validity */ | |
1307 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1308 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1309 | "0x%02x\n", addr_list[i]); | |
1310 | continue; | |
1311 | } | |
1312 | ||
1313 | /* Check address availability */ | |
9b766b81 | 1314 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1315 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1316 | "use, not probing\n", addr_list[i]); | |
1317 | continue; | |
1318 | } | |
1319 | ||
1320 | /* Test address responsiveness | |
1321 | The default probe method is a quick write, but it is known | |
1322 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1323 | and could also irreversibly write-protect some EEPROMs, so | |
1324 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1325 | read instead. Also, some bus drivers don't implement | |
1326 | quick write, so we fallback to a byte read it that case | |
1327 | too. */ | |
1328 | if ((addr_list[i] & ~0x07) == 0x30 | |
1329 | || (addr_list[i] & ~0x0f) == 0x50 | |
1330 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1331 | union i2c_smbus_data data; |
1332 | ||
12b5053a JD |
1333 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1334 | I2C_SMBUS_READ, 0, | |
b25b791b | 1335 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1336 | break; |
1337 | } else { | |
1338 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1339 | I2C_SMBUS_WRITE, 0, | |
1340 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1341 | break; | |
1342 | } | |
1343 | } | |
12b5053a JD |
1344 | |
1345 | if (addr_list[i] == I2C_CLIENT_END) { | |
1346 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1347 | return NULL; | |
1348 | } | |
1349 | ||
1350 | info->addr = addr_list[i]; | |
1351 | return i2c_new_device(adap, info); | |
1352 | } | |
1353 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1354 | ||
1da177e4 LT |
1355 | struct i2c_adapter* i2c_get_adapter(int id) |
1356 | { | |
1da177e4 | 1357 | struct i2c_adapter *adapter; |
438d6c2c | 1358 | |
caada32a | 1359 | mutex_lock(&core_lock); |
1cf92b45 | 1360 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1361 | if (adapter && !try_module_get(adapter->owner)) |
1362 | adapter = NULL; | |
1363 | ||
caada32a | 1364 | mutex_unlock(&core_lock); |
a0920e10 | 1365 | return adapter; |
1da177e4 | 1366 | } |
c0564606 | 1367 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1368 | |
1369 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1370 | { | |
1371 | module_put(adap->owner); | |
1372 | } | |
c0564606 | 1373 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1374 | |
1375 | /* The SMBus parts */ | |
1376 | ||
438d6c2c | 1377 | #define POLY (0x1070U << 3) |
09b8ce0a | 1378 | static u8 crc8(u16 data) |
1da177e4 LT |
1379 | { |
1380 | int i; | |
438d6c2c | 1381 | |
1da177e4 | 1382 | for(i = 0; i < 8; i++) { |
438d6c2c | 1383 | if (data & 0x8000) |
1da177e4 LT |
1384 | data = data ^ POLY; |
1385 | data = data << 1; | |
1386 | } | |
1387 | return (u8)(data >> 8); | |
1388 | } | |
1389 | ||
421ef47b JD |
1390 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1391 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1392 | { |
1393 | int i; | |
1394 | ||
1395 | for(i = 0; i < count; i++) | |
421ef47b | 1396 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1397 | return crc; |
1398 | } | |
1399 | ||
421ef47b JD |
1400 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1401 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1402 | { |
421ef47b JD |
1403 | /* The address will be sent first */ |
1404 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1405 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1406 | ||
1407 | /* The data buffer follows */ | |
1408 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1409 | } |
1410 | ||
421ef47b JD |
1411 | /* Used for write only transactions */ |
1412 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1413 | { |
421ef47b JD |
1414 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1415 | msg->len++; | |
1da177e4 LT |
1416 | } |
1417 | ||
421ef47b JD |
1418 | /* Return <0 on CRC error |
1419 | If there was a write before this read (most cases) we need to take the | |
1420 | partial CRC from the write part into account. | |
1421 | Note that this function does modify the message (we need to decrease the | |
1422 | message length to hide the CRC byte from the caller). */ | |
1423 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1424 | { |
421ef47b JD |
1425 | u8 rpec = msg->buf[--msg->len]; |
1426 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1427 | |
1da177e4 LT |
1428 | if (rpec != cpec) { |
1429 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1430 | rpec, cpec); | |
24a5bb7b | 1431 | return -EBADMSG; |
1da177e4 | 1432 | } |
438d6c2c | 1433 | return 0; |
1da177e4 LT |
1434 | } |
1435 | ||
a1cdedac DB |
1436 | /** |
1437 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1438 | * @client: Handle to slave device | |
1439 | * | |
1440 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1441 | * else the byte received from the device. | |
1442 | */ | |
1da177e4 LT |
1443 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1444 | { | |
1445 | union i2c_smbus_data data; | |
24a5bb7b DB |
1446 | int status; |
1447 | ||
1448 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1449 | I2C_SMBUS_READ, 0, | |
1450 | I2C_SMBUS_BYTE, &data); | |
1451 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1452 | } |
c0564606 | 1453 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1454 | |
a1cdedac DB |
1455 | /** |
1456 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1457 | * @client: Handle to slave device | |
1458 | * @value: Byte to be sent | |
1459 | * | |
1460 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1461 | * else zero on success. | |
1462 | */ | |
1da177e4 LT |
1463 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1464 | { | |
1da177e4 | 1465 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1466 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1467 | } |
c0564606 | 1468 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1469 | |
a1cdedac DB |
1470 | /** |
1471 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1472 | * @client: Handle to slave device | |
1473 | * @command: Byte interpreted by slave | |
1474 | * | |
1475 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1476 | * else a data byte received from the device. | |
1477 | */ | |
1da177e4 LT |
1478 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1479 | { | |
1480 | union i2c_smbus_data data; | |
24a5bb7b DB |
1481 | int status; |
1482 | ||
1483 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1484 | I2C_SMBUS_READ, command, | |
1485 | I2C_SMBUS_BYTE_DATA, &data); | |
1486 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1487 | } |
c0564606 | 1488 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1489 | |
a1cdedac DB |
1490 | /** |
1491 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1492 | * @client: Handle to slave device | |
1493 | * @command: Byte interpreted by slave | |
1494 | * @value: Byte being written | |
1495 | * | |
1496 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1497 | * else zero on success. | |
1498 | */ | |
1da177e4 LT |
1499 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1500 | { | |
1501 | union i2c_smbus_data data; | |
1502 | data.byte = value; | |
1503 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1504 | I2C_SMBUS_WRITE,command, | |
1505 | I2C_SMBUS_BYTE_DATA,&data); | |
1506 | } | |
c0564606 | 1507 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1508 | |
a1cdedac DB |
1509 | /** |
1510 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1511 | * @client: Handle to slave device | |
1512 | * @command: Byte interpreted by slave | |
1513 | * | |
1514 | * This executes the SMBus "read word" protocol, returning negative errno | |
1515 | * else a 16-bit unsigned "word" received from the device. | |
1516 | */ | |
1da177e4 LT |
1517 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1518 | { | |
1519 | union i2c_smbus_data data; | |
24a5bb7b DB |
1520 | int status; |
1521 | ||
1522 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1523 | I2C_SMBUS_READ, command, | |
1524 | I2C_SMBUS_WORD_DATA, &data); | |
1525 | return (status < 0) ? status : data.word; | |
1da177e4 | 1526 | } |
c0564606 | 1527 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1528 | |
a1cdedac DB |
1529 | /** |
1530 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1531 | * @client: Handle to slave device | |
1532 | * @command: Byte interpreted by slave | |
1533 | * @value: 16-bit "word" being written | |
1534 | * | |
1535 | * This executes the SMBus "write word" protocol, returning negative errno | |
1536 | * else zero on success. | |
1537 | */ | |
1da177e4 LT |
1538 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1539 | { | |
1540 | union i2c_smbus_data data; | |
1541 | data.word = value; | |
1542 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1543 | I2C_SMBUS_WRITE,command, | |
1544 | I2C_SMBUS_WORD_DATA,&data); | |
1545 | } | |
c0564606 | 1546 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1547 | |
596c88f4 PM |
1548 | /** |
1549 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1550 | * @client: Handle to slave device | |
1551 | * @command: Byte interpreted by slave | |
1552 | * @value: 16-bit "word" being written | |
1553 | * | |
1554 | * This executes the SMBus "process call" protocol, returning negative errno | |
1555 | * else a 16-bit unsigned "word" received from the device. | |
1556 | */ | |
1557 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1558 | { | |
1559 | union i2c_smbus_data data; | |
1560 | int status; | |
1561 | data.word = value; | |
1562 | ||
1563 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1564 | I2C_SMBUS_WRITE, command, | |
1565 | I2C_SMBUS_PROC_CALL, &data); | |
1566 | return (status < 0) ? status : data.word; | |
1567 | } | |
1568 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1569 | ||
a64ec07d | 1570 | /** |
a1cdedac | 1571 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1572 | * @client: Handle to slave device |
a1cdedac | 1573 | * @command: Byte interpreted by slave |
a64ec07d DB |
1574 | * @values: Byte array into which data will be read; big enough to hold |
1575 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1576 | * | |
a1cdedac DB |
1577 | * This executes the SMBus "block read" protocol, returning negative errno |
1578 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1579 | * |
1580 | * Note that using this function requires that the client's adapter support | |
1581 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1582 | * support this; its emulation through I2C messaging relies on a specific | |
1583 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1584 | */ | |
b86a1bc8 JD |
1585 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1586 | u8 *values) | |
1587 | { | |
1588 | union i2c_smbus_data data; | |
24a5bb7b | 1589 | int status; |
b86a1bc8 | 1590 | |
24a5bb7b DB |
1591 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1592 | I2C_SMBUS_READ, command, | |
1593 | I2C_SMBUS_BLOCK_DATA, &data); | |
1594 | if (status) | |
1595 | return status; | |
b86a1bc8 JD |
1596 | |
1597 | memcpy(values, &data.block[1], data.block[0]); | |
1598 | return data.block[0]; | |
1599 | } | |
1600 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1601 | ||
a1cdedac DB |
1602 | /** |
1603 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1604 | * @client: Handle to slave device | |
1605 | * @command: Byte interpreted by slave | |
1606 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1607 | * @values: Byte array which will be written. | |
1608 | * | |
1609 | * This executes the SMBus "block write" protocol, returning negative errno | |
1610 | * else zero on success. | |
1611 | */ | |
1da177e4 | 1612 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1613 | u8 length, const u8 *values) |
1da177e4 LT |
1614 | { |
1615 | union i2c_smbus_data data; | |
7656032b | 1616 | |
1da177e4 LT |
1617 | if (length > I2C_SMBUS_BLOCK_MAX) |
1618 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1619 | data.block[0] = length; |
7656032b | 1620 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1621 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1622 | I2C_SMBUS_WRITE,command, | |
1623 | I2C_SMBUS_BLOCK_DATA,&data); | |
1624 | } | |
c0564606 | 1625 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1626 | |
1627 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1628 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1629 | u8 length, u8 *values) | |
1da177e4 LT |
1630 | { |
1631 | union i2c_smbus_data data; | |
24a5bb7b | 1632 | int status; |
7656032b | 1633 | |
4b2643d7 JD |
1634 | if (length > I2C_SMBUS_BLOCK_MAX) |
1635 | length = I2C_SMBUS_BLOCK_MAX; | |
1636 | data.block[0] = length; | |
24a5bb7b DB |
1637 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1638 | I2C_SMBUS_READ, command, | |
1639 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1640 | if (status < 0) | |
1641 | return status; | |
7656032b JD |
1642 | |
1643 | memcpy(values, &data.block[1], data.block[0]); | |
1644 | return data.block[0]; | |
1da177e4 | 1645 | } |
c0564606 | 1646 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1647 | |
21bbd691 | 1648 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1649 | u8 length, const u8 *values) |
21bbd691 JD |
1650 | { |
1651 | union i2c_smbus_data data; | |
1652 | ||
1653 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1654 | length = I2C_SMBUS_BLOCK_MAX; | |
1655 | data.block[0] = length; | |
1656 | memcpy(data.block + 1, values, length); | |
1657 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1658 | I2C_SMBUS_WRITE, command, | |
1659 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1660 | } | |
c0564606 | 1661 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1662 | |
438d6c2c | 1663 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1664 | No checking of parameters is done! */ |
438d6c2c | 1665 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1666 | unsigned short flags, |
438d6c2c | 1667 | char read_write, u8 command, int size, |
1da177e4 LT |
1668 | union i2c_smbus_data * data) |
1669 | { | |
1670 | /* So we need to generate a series of msgs. In the case of writing, we | |
1671 | need to use only one message; when reading, we need two. We initialize | |
1672 | most things with sane defaults, to keep the code below somewhat | |
1673 | simpler. */ | |
5c50d188 HI |
1674 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1675 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1676 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1677 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1678 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1679 | }; | |
1680 | int i; | |
421ef47b | 1681 | u8 partial_pec = 0; |
24a5bb7b | 1682 | int status; |
1da177e4 LT |
1683 | |
1684 | msgbuf0[0] = command; | |
1685 | switch(size) { | |
1686 | case I2C_SMBUS_QUICK: | |
1687 | msg[0].len = 0; | |
1688 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1689 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1690 | I2C_M_RD : 0); | |
1da177e4 LT |
1691 | num = 1; |
1692 | break; | |
1693 | case I2C_SMBUS_BYTE: | |
1694 | if (read_write == I2C_SMBUS_READ) { | |
1695 | /* Special case: only a read! */ | |
1696 | msg[0].flags = I2C_M_RD | flags; | |
1697 | num = 1; | |
1698 | } | |
1699 | break; | |
1700 | case I2C_SMBUS_BYTE_DATA: | |
1701 | if (read_write == I2C_SMBUS_READ) | |
1702 | msg[1].len = 1; | |
1703 | else { | |
1704 | msg[0].len = 2; | |
1705 | msgbuf0[1] = data->byte; | |
1706 | } | |
1707 | break; | |
1708 | case I2C_SMBUS_WORD_DATA: | |
1709 | if (read_write == I2C_SMBUS_READ) | |
1710 | msg[1].len = 2; | |
1711 | else { | |
1712 | msg[0].len=3; | |
1713 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1714 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1715 | } |
1716 | break; | |
1717 | case I2C_SMBUS_PROC_CALL: | |
1718 | num = 2; /* Special case */ | |
1719 | read_write = I2C_SMBUS_READ; | |
1720 | msg[0].len = 3; | |
1721 | msg[1].len = 2; | |
1722 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1723 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1724 | break; |
1725 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1726 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1727 | msg[1].flags |= I2C_M_RECV_LEN; |
1728 | msg[1].len = 1; /* block length will be added by | |
1729 | the underlying bus driver */ | |
1da177e4 LT |
1730 | } else { |
1731 | msg[0].len = data->block[0] + 2; | |
1732 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1733 | dev_err(&adapter->dev, |
1734 | "Invalid block write size %d\n", | |
1735 | data->block[0]); | |
1736 | return -EINVAL; | |
1da177e4 | 1737 | } |
5c50d188 | 1738 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1739 | msgbuf0[i] = data->block[i-1]; |
1740 | } | |
1741 | break; | |
1742 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1743 | num = 2; /* Another special case */ |
1744 | read_write = I2C_SMBUS_READ; | |
1745 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1746 | dev_err(&adapter->dev, |
1747 | "Invalid block write size %d\n", | |
209d27c3 | 1748 | data->block[0]); |
24a5bb7b | 1749 | return -EINVAL; |
209d27c3 JD |
1750 | } |
1751 | msg[0].len = data->block[0] + 2; | |
1752 | for (i = 1; i < msg[0].len; i++) | |
1753 | msgbuf0[i] = data->block[i-1]; | |
1754 | msg[1].flags |= I2C_M_RECV_LEN; | |
1755 | msg[1].len = 1; /* block length will be added by | |
1756 | the underlying bus driver */ | |
1757 | break; | |
1da177e4 LT |
1758 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1759 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1760 | msg[1].len = data->block[0]; |
1da177e4 LT |
1761 | } else { |
1762 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1763 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1764 | dev_err(&adapter->dev, |
1765 | "Invalid block write size %d\n", | |
1766 | data->block[0]); | |
1767 | return -EINVAL; | |
1da177e4 LT |
1768 | } |
1769 | for (i = 1; i <= data->block[0]; i++) | |
1770 | msgbuf0[i] = data->block[i]; | |
1771 | } | |
1772 | break; | |
1773 | default: | |
24a5bb7b DB |
1774 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1775 | return -EOPNOTSUPP; | |
1da177e4 LT |
1776 | } |
1777 | ||
421ef47b JD |
1778 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1779 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1780 | if (i) { | |
1781 | /* Compute PEC if first message is a write */ | |
1782 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1783 | if (num == 1) /* Write only */ |
421ef47b JD |
1784 | i2c_smbus_add_pec(&msg[0]); |
1785 | else /* Write followed by read */ | |
1786 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1787 | } | |
1788 | /* Ask for PEC if last message is a read */ | |
1789 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1790 | msg[num-1].len++; |
421ef47b JD |
1791 | } |
1792 | ||
24a5bb7b DB |
1793 | status = i2c_transfer(adapter, msg, num); |
1794 | if (status < 0) | |
1795 | return status; | |
1da177e4 | 1796 | |
421ef47b JD |
1797 | /* Check PEC if last message is a read */ |
1798 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1799 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1800 | if (status < 0) | |
1801 | return status; | |
421ef47b JD |
1802 | } |
1803 | ||
1da177e4 LT |
1804 | if (read_write == I2C_SMBUS_READ) |
1805 | switch(size) { | |
1806 | case I2C_SMBUS_BYTE: | |
1807 | data->byte = msgbuf0[0]; | |
1808 | break; | |
1809 | case I2C_SMBUS_BYTE_DATA: | |
1810 | data->byte = msgbuf1[0]; | |
1811 | break; | |
438d6c2c | 1812 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1813 | case I2C_SMBUS_PROC_CALL: |
1814 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1815 | break; | |
1816 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1817 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1818 | data->block[i+1] = msgbuf1[i]; |
1819 | break; | |
209d27c3 JD |
1820 | case I2C_SMBUS_BLOCK_DATA: |
1821 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1822 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1823 | data->block[i] = msgbuf1[i]; | |
1824 | break; | |
1da177e4 LT |
1825 | } |
1826 | return 0; | |
1827 | } | |
1828 | ||
a1cdedac DB |
1829 | /** |
1830 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1831 | * @adapter: Handle to I2C bus | |
1832 | * @addr: Address of SMBus slave on that bus | |
1833 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1834 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1835 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1836 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1837 | * @data: Data to be read or written | |
1838 | * | |
1839 | * This executes an SMBus protocol operation, and returns a negative | |
1840 | * errno code else zero on success. | |
1841 | */ | |
09b8ce0a | 1842 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1843 | char read_write, u8 command, int protocol, |
09b8ce0a | 1844 | union i2c_smbus_data *data) |
1da177e4 | 1845 | { |
66b650f0 CW |
1846 | unsigned long orig_jiffies; |
1847 | int try; | |
1da177e4 | 1848 | s32 res; |
1da177e4 LT |
1849 | |
1850 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1851 | |
1852 | if (adapter->algo->smbus_xfer) { | |
194684e5 | 1853 | rt_mutex_lock(&adapter->bus_lock); |
66b650f0 CW |
1854 | |
1855 | /* Retry automatically on arbitration loss */ | |
1856 | orig_jiffies = jiffies; | |
1857 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
1858 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
1859 | read_write, command, | |
1860 | protocol, data); | |
1861 | if (res != -EAGAIN) | |
1862 | break; | |
1863 | if (time_after(jiffies, | |
1864 | orig_jiffies + adapter->timeout)) | |
1865 | break; | |
1866 | } | |
194684e5 | 1867 | rt_mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1868 | } else |
1869 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1870 | command, protocol, data); |
1da177e4 | 1871 | |
1da177e4 LT |
1872 | return res; |
1873 | } | |
1da177e4 | 1874 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1875 | |
1876 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1877 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1878 | MODULE_LICENSE("GPL"); |