Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* i2c-core.c - a device driver for the iic-bus interface */ |
2 | /* ------------------------------------------------------------------------- */ | |
3 | /* Copyright (C) 1995-99 Simon G. Vogl | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
18 | /* ------------------------------------------------------------------------- */ | |
19 | ||
96de0e25 | 20 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 21 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b JD |
22 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
23 | Jean Delvare <khali@linux-fr.org> */ | |
1da177e4 | 24 | |
1da177e4 LT |
25 | #include <linux/module.h> |
26 | #include <linux/kernel.h> | |
27 | #include <linux/errno.h> | |
28 | #include <linux/slab.h> | |
29 | #include <linux/i2c.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/idr.h> | |
b3585e4f | 32 | #include <linux/mutex.h> |
b8d6f45b | 33 | #include <linux/completion.h> |
cea443a8 MR |
34 | #include <linux/hardirq.h> |
35 | #include <linux/irqflags.h> | |
1da177e4 LT |
36 | #include <asm/uaccess.h> |
37 | ||
9c1600ed DB |
38 | #include "i2c-core.h" |
39 | ||
1da177e4 | 40 | |
35fc37f8 JD |
41 | /* core_lock protects i2c_adapter_idr, and guarantees |
42 | that device detection, deletion of detected devices, and attach_adapter | |
43 | and detach_adapter calls are serialized */ | |
caada32a | 44 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
45 | static DEFINE_IDR(i2c_adapter_idr); |
46 | ||
f8a227e8 | 47 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr); |
4735c98f | 48 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
49 | |
50 | /* ------------------------------------------------------------------------- */ | |
51 | ||
d2653e92 JD |
52 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
53 | const struct i2c_client *client) | |
54 | { | |
55 | while (id->name[0]) { | |
56 | if (strcmp(client->name, id->name) == 0) | |
57 | return id; | |
58 | id++; | |
59 | } | |
60 | return NULL; | |
61 | } | |
62 | ||
1da177e4 LT |
63 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
64 | { | |
7b4fbc50 DB |
65 | struct i2c_client *client = to_i2c_client(dev); |
66 | struct i2c_driver *driver = to_i2c_driver(drv); | |
67 | ||
d2653e92 JD |
68 | /* match on an id table if there is one */ |
69 | if (driver->id_table) | |
70 | return i2c_match_id(driver->id_table, client) != NULL; | |
71 | ||
eb8a7908 | 72 | return 0; |
1da177e4 LT |
73 | } |
74 | ||
7b4fbc50 DB |
75 | #ifdef CONFIG_HOTPLUG |
76 | ||
77 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 78 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
79 | { |
80 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 81 | |
eb8a7908 JD |
82 | if (add_uevent_var(env, "MODALIAS=%s%s", |
83 | I2C_MODULE_PREFIX, client->name)) | |
84 | return -ENOMEM; | |
7b4fbc50 DB |
85 | dev_dbg(dev, "uevent\n"); |
86 | return 0; | |
87 | } | |
88 | ||
89 | #else | |
90 | #define i2c_device_uevent NULL | |
91 | #endif /* CONFIG_HOTPLUG */ | |
92 | ||
f37dd80a | 93 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 94 | { |
7b4fbc50 DB |
95 | struct i2c_client *client = to_i2c_client(dev); |
96 | struct i2c_driver *driver = to_i2c_driver(dev->driver); | |
50c3304a | 97 | int status; |
7b4fbc50 | 98 | |
e0457442 | 99 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
100 | return -ENODEV; |
101 | client->driver = driver; | |
ee35425c MP |
102 | if (!device_can_wakeup(&client->dev)) |
103 | device_init_wakeup(&client->dev, | |
104 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 105 | dev_dbg(dev, "probe\n"); |
d2653e92 | 106 | |
e0457442 | 107 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
50c3304a HV |
108 | if (status) |
109 | client->driver = NULL; | |
110 | return status; | |
f37dd80a | 111 | } |
1da177e4 | 112 | |
f37dd80a DB |
113 | static int i2c_device_remove(struct device *dev) |
114 | { | |
a1d9e6e4 DB |
115 | struct i2c_client *client = to_i2c_client(dev); |
116 | struct i2c_driver *driver; | |
117 | int status; | |
118 | ||
119 | if (!dev->driver) | |
120 | return 0; | |
121 | ||
122 | driver = to_i2c_driver(dev->driver); | |
123 | if (driver->remove) { | |
124 | dev_dbg(dev, "remove\n"); | |
125 | status = driver->remove(client); | |
126 | } else { | |
127 | dev->driver = NULL; | |
128 | status = 0; | |
129 | } | |
130 | if (status == 0) | |
131 | client->driver = NULL; | |
132 | return status; | |
1da177e4 LT |
133 | } |
134 | ||
f37dd80a | 135 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 136 | { |
f37dd80a DB |
137 | struct i2c_driver *driver; |
138 | ||
139 | if (!dev->driver) | |
140 | return; | |
141 | driver = to_i2c_driver(dev->driver); | |
142 | if (driver->shutdown) | |
143 | driver->shutdown(to_i2c_client(dev)); | |
1da177e4 LT |
144 | } |
145 | ||
09b8ce0a | 146 | static int i2c_device_suspend(struct device *dev, pm_message_t mesg) |
1da177e4 | 147 | { |
f37dd80a DB |
148 | struct i2c_driver *driver; |
149 | ||
150 | if (!dev->driver) | |
151 | return 0; | |
152 | driver = to_i2c_driver(dev->driver); | |
153 | if (!driver->suspend) | |
154 | return 0; | |
155 | return driver->suspend(to_i2c_client(dev), mesg); | |
1da177e4 LT |
156 | } |
157 | ||
09b8ce0a | 158 | static int i2c_device_resume(struct device *dev) |
1da177e4 | 159 | { |
f37dd80a DB |
160 | struct i2c_driver *driver; |
161 | ||
162 | if (!dev->driver) | |
163 | return 0; | |
164 | driver = to_i2c_driver(dev->driver); | |
165 | if (!driver->resume) | |
166 | return 0; | |
167 | return driver->resume(to_i2c_client(dev)); | |
1da177e4 LT |
168 | } |
169 | ||
9c1600ed DB |
170 | static void i2c_client_dev_release(struct device *dev) |
171 | { | |
172 | kfree(to_i2c_client(dev)); | |
173 | } | |
174 | ||
09b8ce0a ZX |
175 | static ssize_t |
176 | show_client_name(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
177 | { |
178 | struct i2c_client *client = to_i2c_client(dev); | |
179 | return sprintf(buf, "%s\n", client->name); | |
180 | } | |
181 | ||
09b8ce0a ZX |
182 | static ssize_t |
183 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
184 | { |
185 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 186 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
187 | } |
188 | ||
189 | static struct device_attribute i2c_dev_attrs[] = { | |
190 | __ATTR(name, S_IRUGO, show_client_name, NULL), | |
191 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ | |
192 | __ATTR(modalias, S_IRUGO, show_modalias, NULL), | |
193 | { }, | |
194 | }; | |
195 | ||
e9ca9eb9 | 196 | struct bus_type i2c_bus_type = { |
f37dd80a | 197 | .name = "i2c", |
7b4fbc50 | 198 | .dev_attrs = i2c_dev_attrs, |
f37dd80a | 199 | .match = i2c_device_match, |
7b4fbc50 | 200 | .uevent = i2c_device_uevent, |
f37dd80a DB |
201 | .probe = i2c_device_probe, |
202 | .remove = i2c_device_remove, | |
203 | .shutdown = i2c_device_shutdown, | |
204 | .suspend = i2c_device_suspend, | |
205 | .resume = i2c_device_resume, | |
b864c7d5 | 206 | }; |
e9ca9eb9 | 207 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 208 | |
9b766b81 DB |
209 | |
210 | /** | |
211 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
212 | * @dev: device, probably from some driver model iterator | |
213 | * | |
214 | * When traversing the driver model tree, perhaps using driver model | |
215 | * iterators like @device_for_each_child(), you can't assume very much | |
216 | * about the nodes you find. Use this function to avoid oopses caused | |
217 | * by wrongly treating some non-I2C device as an i2c_client. | |
218 | */ | |
219 | struct i2c_client *i2c_verify_client(struct device *dev) | |
220 | { | |
221 | return (dev->bus == &i2c_bus_type) | |
222 | ? to_i2c_client(dev) | |
223 | : NULL; | |
224 | } | |
225 | EXPORT_SYMBOL(i2c_verify_client); | |
226 | ||
227 | ||
9c1600ed | 228 | /** |
f8a227e8 | 229 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
230 | * @adap: the adapter managing the device |
231 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 232 | * Context: can sleep |
9c1600ed | 233 | * |
f8a227e8 JD |
234 | * Create an i2c device. Binding is handled through driver model |
235 | * probe()/remove() methods. A driver may be bound to this device when we | |
236 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
237 | * load the driver module). This call is not appropriate for use by mainboard | |
238 | * initialization logic, which usually runs during an arch_initcall() long | |
239 | * before any i2c_adapter could exist. | |
9c1600ed DB |
240 | * |
241 | * This returns the new i2c client, which may be saved for later use with | |
242 | * i2c_unregister_device(); or NULL to indicate an error. | |
243 | */ | |
244 | struct i2c_client * | |
245 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
246 | { | |
247 | struct i2c_client *client; | |
248 | int status; | |
249 | ||
250 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
251 | if (!client) | |
252 | return NULL; | |
253 | ||
254 | client->adapter = adap; | |
255 | ||
256 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 257 | |
11f1f2af AV |
258 | if (info->archdata) |
259 | client->dev.archdata = *info->archdata; | |
260 | ||
ee35425c | 261 | client->flags = info->flags; |
9c1600ed DB |
262 | client->addr = info->addr; |
263 | client->irq = info->irq; | |
264 | ||
9c1600ed DB |
265 | strlcpy(client->name, info->type, sizeof(client->name)); |
266 | ||
f8a227e8 JD |
267 | /* Check for address business */ |
268 | status = i2c_check_addr(adap, client->addr); | |
269 | if (status) | |
270 | goto out_err; | |
271 | ||
272 | client->dev.parent = &client->adapter->dev; | |
273 | client->dev.bus = &i2c_bus_type; | |
1e40ac12 | 274 | client->dev.release = i2c_client_dev_release; |
f8a227e8 JD |
275 | |
276 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), | |
277 | client->addr); | |
278 | status = device_register(&client->dev); | |
279 | if (status) | |
280 | goto out_err; | |
281 | ||
f8a227e8 JD |
282 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
283 | client->name, dev_name(&client->dev)); | |
284 | ||
9c1600ed | 285 | return client; |
f8a227e8 JD |
286 | |
287 | out_err: | |
288 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
289 | "(%d)\n", client->name, client->addr, status); | |
290 | kfree(client); | |
291 | return NULL; | |
9c1600ed DB |
292 | } |
293 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
294 | ||
295 | ||
296 | /** | |
297 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
298 | * @client: value returned from i2c_new_device() | |
d64f73be | 299 | * Context: can sleep |
9c1600ed DB |
300 | */ |
301 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 302 | { |
a1d9e6e4 DB |
303 | device_unregister(&client->dev); |
304 | } | |
9c1600ed | 305 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
306 | |
307 | ||
60b129d7 JD |
308 | static const struct i2c_device_id dummy_id[] = { |
309 | { "dummy", 0 }, | |
310 | { }, | |
311 | }; | |
312 | ||
d2653e92 JD |
313 | static int dummy_probe(struct i2c_client *client, |
314 | const struct i2c_device_id *id) | |
315 | { | |
316 | return 0; | |
317 | } | |
318 | ||
319 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
320 | { |
321 | return 0; | |
322 | } | |
323 | ||
324 | static struct i2c_driver dummy_driver = { | |
325 | .driver.name = "dummy", | |
d2653e92 JD |
326 | .probe = dummy_probe, |
327 | .remove = dummy_remove, | |
60b129d7 | 328 | .id_table = dummy_id, |
e9f1373b DB |
329 | }; |
330 | ||
331 | /** | |
332 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
333 | * @adapter: the adapter managing the device | |
334 | * @address: seven bit address to be used | |
e9f1373b DB |
335 | * Context: can sleep |
336 | * | |
337 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
338 | * with devices that consume multiple addresses. Examples of such chips | |
339 | * include various EEPROMS (like 24c04 and 24c08 models). | |
340 | * | |
341 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
342 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
343 | * And second, this prevents the specified address from being bound to a | |
344 | * different driver. | |
345 | * | |
346 | * This returns the new i2c client, which should be saved for later use with | |
347 | * i2c_unregister_device(); or NULL to indicate an error. | |
348 | */ | |
09b8ce0a | 349 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
350 | { |
351 | struct i2c_board_info info = { | |
60b129d7 | 352 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
353 | }; |
354 | ||
e9f1373b DB |
355 | return i2c_new_device(adapter, &info); |
356 | } | |
357 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
358 | ||
f37dd80a DB |
359 | /* ------------------------------------------------------------------------- */ |
360 | ||
16ffadfc DB |
361 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
362 | ||
83eaaed0 | 363 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 364 | { |
ef2c8321 | 365 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
366 | complete(&adap->dev_released); |
367 | } | |
368 | ||
16ffadfc DB |
369 | static ssize_t |
370 | show_adapter_name(struct device *dev, struct device_attribute *attr, char *buf) | |
371 | { | |
ef2c8321 | 372 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
16ffadfc DB |
373 | return sprintf(buf, "%s\n", adap->name); |
374 | } | |
b119dc3f | 375 | |
16ffadfc DB |
376 | static struct device_attribute i2c_adapter_attrs[] = { |
377 | __ATTR(name, S_IRUGO, show_adapter_name, NULL), | |
378 | { }, | |
379 | }; | |
b119dc3f | 380 | |
83eaaed0 | 381 | static struct class i2c_adapter_class = { |
b119dc3f DB |
382 | .owner = THIS_MODULE, |
383 | .name = "i2c-adapter", | |
16ffadfc | 384 | .dev_attrs = i2c_adapter_attrs, |
1da177e4 LT |
385 | }; |
386 | ||
9c1600ed DB |
387 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
388 | { | |
389 | struct i2c_devinfo *devinfo; | |
390 | ||
391 | mutex_lock(&__i2c_board_lock); | |
392 | list_for_each_entry(devinfo, &__i2c_board_list, list) { | |
393 | if (devinfo->busnum == adapter->nr | |
394 | && !i2c_new_device(adapter, | |
395 | &devinfo->board_info)) | |
09b8ce0a ZX |
396 | dev_err(&adapter->dev, |
397 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
398 | devinfo->board_info.addr); |
399 | } | |
400 | mutex_unlock(&__i2c_board_lock); | |
401 | } | |
402 | ||
026526f5 JD |
403 | static int i2c_do_add_adapter(struct device_driver *d, void *data) |
404 | { | |
405 | struct i2c_driver *driver = to_i2c_driver(d); | |
406 | struct i2c_adapter *adap = data; | |
407 | ||
4735c98f JD |
408 | /* Detect supported devices on that bus, and instantiate them */ |
409 | i2c_detect(adap, driver); | |
410 | ||
411 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 JD |
412 | if (driver->attach_adapter) { |
413 | /* We ignore the return code; if it fails, too bad */ | |
414 | driver->attach_adapter(adap); | |
415 | } | |
416 | return 0; | |
417 | } | |
418 | ||
6e13e641 | 419 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 420 | { |
026526f5 | 421 | int res = 0, dummy; |
1da177e4 | 422 | |
1d0b19c9 | 423 | /* Can't register until after driver model init */ |
35fc37f8 JD |
424 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
425 | res = -EAGAIN; | |
426 | goto out_list; | |
427 | } | |
1d0b19c9 | 428 | |
5c085d36 | 429 | mutex_init(&adap->bus_lock); |
1da177e4 | 430 | |
8fcfef6e JD |
431 | /* Set default timeout to 1 second if not already set */ |
432 | if (adap->timeout == 0) | |
433 | adap->timeout = HZ; | |
434 | ||
27d9c183 | 435 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
1da177e4 | 436 | adap->dev.release = &i2c_adapter_dev_release; |
fccb56e4 | 437 | adap->dev.class = &i2c_adapter_class; |
b119c6c9 JD |
438 | res = device_register(&adap->dev); |
439 | if (res) | |
440 | goto out_list; | |
1da177e4 | 441 | |
b6d7b3d1 JD |
442 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
443 | ||
729d6dd5 | 444 | /* create pre-declared device nodes */ |
6e13e641 DB |
445 | if (adap->nr < __i2c_first_dynamic_bus_num) |
446 | i2c_scan_static_board_info(adap); | |
447 | ||
4735c98f | 448 | /* Notify drivers */ |
35fc37f8 | 449 | mutex_lock(&core_lock); |
026526f5 JD |
450 | dummy = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
451 | i2c_do_add_adapter); | |
caada32a | 452 | mutex_unlock(&core_lock); |
35fc37f8 JD |
453 | |
454 | return 0; | |
b119c6c9 | 455 | |
b119c6c9 | 456 | out_list: |
35fc37f8 | 457 | mutex_lock(&core_lock); |
b119c6c9 | 458 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
459 | mutex_unlock(&core_lock); |
460 | return res; | |
1da177e4 LT |
461 | } |
462 | ||
6e13e641 DB |
463 | /** |
464 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
465 | * @adapter: the adapter to add | |
d64f73be | 466 | * Context: can sleep |
6e13e641 DB |
467 | * |
468 | * This routine is used to declare an I2C adapter when its bus number | |
469 | * doesn't matter. Examples: for I2C adapters dynamically added by | |
470 | * USB links or PCI plugin cards. | |
471 | * | |
472 | * When this returns zero, a new bus number was allocated and stored | |
473 | * in adap->nr, and the specified adapter became available for clients. | |
474 | * Otherwise, a negative errno value is returned. | |
475 | */ | |
476 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
477 | { | |
478 | int id, res = 0; | |
479 | ||
480 | retry: | |
481 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
482 | return -ENOMEM; | |
483 | ||
caada32a | 484 | mutex_lock(&core_lock); |
6e13e641 DB |
485 | /* "above" here means "above or equal to", sigh */ |
486 | res = idr_get_new_above(&i2c_adapter_idr, adapter, | |
487 | __i2c_first_dynamic_bus_num, &id); | |
caada32a | 488 | mutex_unlock(&core_lock); |
6e13e641 DB |
489 | |
490 | if (res < 0) { | |
491 | if (res == -EAGAIN) | |
492 | goto retry; | |
493 | return res; | |
494 | } | |
495 | ||
496 | adapter->nr = id; | |
497 | return i2c_register_adapter(adapter); | |
498 | } | |
499 | EXPORT_SYMBOL(i2c_add_adapter); | |
500 | ||
501 | /** | |
502 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
503 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 504 | * Context: can sleep |
6e13e641 DB |
505 | * |
506 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
507 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
508 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
509 | * is used to properly configure I2C devices. |
510 | * | |
511 | * If no devices have pre-been declared for this bus, then be sure to | |
512 | * register the adapter before any dynamically allocated ones. Otherwise | |
513 | * the required bus ID may not be available. | |
514 | * | |
515 | * When this returns zero, the specified adapter became available for | |
516 | * clients using the bus number provided in adap->nr. Also, the table | |
517 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
518 | * and the appropriate driver model device nodes are created. Otherwise, a | |
519 | * negative errno value is returned. | |
520 | */ | |
521 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
522 | { | |
523 | int id; | |
524 | int status; | |
525 | ||
526 | if (adap->nr & ~MAX_ID_MASK) | |
527 | return -EINVAL; | |
528 | ||
529 | retry: | |
530 | if (idr_pre_get(&i2c_adapter_idr, GFP_KERNEL) == 0) | |
531 | return -ENOMEM; | |
532 | ||
caada32a | 533 | mutex_lock(&core_lock); |
6e13e641 DB |
534 | /* "above" here means "above or equal to", sigh; |
535 | * we need the "equal to" result to force the result | |
536 | */ | |
537 | status = idr_get_new_above(&i2c_adapter_idr, adap, adap->nr, &id); | |
538 | if (status == 0 && id != adap->nr) { | |
539 | status = -EBUSY; | |
540 | idr_remove(&i2c_adapter_idr, id); | |
541 | } | |
caada32a | 542 | mutex_unlock(&core_lock); |
6e13e641 DB |
543 | if (status == -EAGAIN) |
544 | goto retry; | |
545 | ||
546 | if (status == 0) | |
547 | status = i2c_register_adapter(adap); | |
548 | return status; | |
549 | } | |
550 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
551 | ||
026526f5 JD |
552 | static int i2c_do_del_adapter(struct device_driver *d, void *data) |
553 | { | |
554 | struct i2c_driver *driver = to_i2c_driver(d); | |
555 | struct i2c_adapter *adapter = data; | |
4735c98f | 556 | struct i2c_client *client, *_n; |
026526f5 JD |
557 | int res; |
558 | ||
acec211c JD |
559 | /* Remove the devices we created ourselves as the result of hardware |
560 | * probing (using a driver's detect method) */ | |
4735c98f JD |
561 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
562 | if (client->adapter == adapter) { | |
563 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
564 | client->name, client->addr); | |
565 | list_del(&client->detected); | |
566 | i2c_unregister_device(client); | |
567 | } | |
568 | } | |
569 | ||
026526f5 JD |
570 | if (!driver->detach_adapter) |
571 | return 0; | |
572 | res = driver->detach_adapter(adapter); | |
573 | if (res) | |
574 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
575 | "for driver [%s]\n", res, driver->driver.name); | |
576 | return res; | |
577 | } | |
578 | ||
e549c2b5 JD |
579 | static int __unregister_client(struct device *dev, void *dummy) |
580 | { | |
581 | struct i2c_client *client = i2c_verify_client(dev); | |
582 | if (client) | |
583 | i2c_unregister_device(client); | |
584 | return 0; | |
585 | } | |
586 | ||
d64f73be DB |
587 | /** |
588 | * i2c_del_adapter - unregister I2C adapter | |
589 | * @adap: the adapter being unregistered | |
590 | * Context: can sleep | |
591 | * | |
592 | * This unregisters an I2C adapter which was previously registered | |
593 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
594 | */ | |
1da177e4 LT |
595 | int i2c_del_adapter(struct i2c_adapter *adap) |
596 | { | |
1da177e4 | 597 | int res = 0; |
35fc37f8 | 598 | struct i2c_adapter *found; |
1da177e4 LT |
599 | |
600 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
601 | mutex_lock(&core_lock); |
602 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
603 | mutex_unlock(&core_lock); | |
604 | if (found != adap) { | |
b6d7b3d1 JD |
605 | pr_debug("i2c-core: attempting to delete unregistered " |
606 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 607 | return -EINVAL; |
1da177e4 LT |
608 | } |
609 | ||
026526f5 | 610 | /* Tell drivers about this removal */ |
35fc37f8 | 611 | mutex_lock(&core_lock); |
026526f5 JD |
612 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
613 | i2c_do_del_adapter); | |
35fc37f8 | 614 | mutex_unlock(&core_lock); |
026526f5 | 615 | if (res) |
35fc37f8 | 616 | return res; |
1da177e4 | 617 | |
e549c2b5 JD |
618 | /* Detach any active clients. This can't fail, thus we do not |
619 | checking the returned value. */ | |
620 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); | |
1da177e4 LT |
621 | |
622 | /* clean up the sysfs representation */ | |
623 | init_completion(&adap->dev_released); | |
1da177e4 | 624 | device_unregister(&adap->dev); |
1da177e4 LT |
625 | |
626 | /* wait for sysfs to drop all references */ | |
627 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 628 | |
6e13e641 | 629 | /* free bus id */ |
35fc37f8 | 630 | mutex_lock(&core_lock); |
1da177e4 | 631 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 632 | mutex_unlock(&core_lock); |
1da177e4 | 633 | |
b6d7b3d1 | 634 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); |
1da177e4 | 635 | |
bd4bc3db JD |
636 | /* Clear the device structure in case this adapter is ever going to be |
637 | added again */ | |
638 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
639 | ||
35fc37f8 | 640 | return 0; |
1da177e4 | 641 | } |
c0564606 | 642 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
643 | |
644 | ||
7b4fbc50 DB |
645 | /* ------------------------------------------------------------------------- */ |
646 | ||
7f101a97 DY |
647 | static int __attach_adapter(struct device *dev, void *data) |
648 | { | |
649 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
650 | struct i2c_driver *driver = data; | |
651 | ||
4735c98f JD |
652 | i2c_detect(adapter, driver); |
653 | ||
654 | /* Legacy drivers scan i2c busses directly */ | |
655 | if (driver->attach_adapter) | |
656 | driver->attach_adapter(adapter); | |
7f101a97 DY |
657 | |
658 | return 0; | |
659 | } | |
660 | ||
7b4fbc50 DB |
661 | /* |
662 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 663 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
664 | */ |
665 | ||
de59cf9e | 666 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 667 | { |
7eebcb7c | 668 | int res; |
1da177e4 | 669 | |
1d0b19c9 DB |
670 | /* Can't register until after driver model init */ |
671 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
672 | return -EAGAIN; | |
673 | ||
1da177e4 | 674 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 675 | driver->driver.owner = owner; |
1da177e4 | 676 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 677 | |
729d6dd5 | 678 | /* When registration returns, the driver core |
6e13e641 DB |
679 | * will have called probe() for all matching-but-unbound devices. |
680 | */ | |
1da177e4 LT |
681 | res = driver_register(&driver->driver); |
682 | if (res) | |
7eebcb7c | 683 | return res; |
438d6c2c | 684 | |
35d8b2e6 | 685 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 686 | |
4735c98f JD |
687 | INIT_LIST_HEAD(&driver->clients); |
688 | /* Walk the adapters that are already present */ | |
35fc37f8 | 689 | mutex_lock(&core_lock); |
93562b53 GKH |
690 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
691 | __attach_adapter); | |
7f101a97 | 692 | mutex_unlock(&core_lock); |
35fc37f8 | 693 | |
7f101a97 DY |
694 | return 0; |
695 | } | |
696 | EXPORT_SYMBOL(i2c_register_driver); | |
697 | ||
698 | static int __detach_adapter(struct device *dev, void *data) | |
699 | { | |
700 | struct i2c_adapter *adapter = to_i2c_adapter(dev); | |
701 | struct i2c_driver *driver = data; | |
4735c98f JD |
702 | struct i2c_client *client, *_n; |
703 | ||
acec211c JD |
704 | /* Remove the devices we created ourselves as the result of hardware |
705 | * probing (using a driver's detect method) */ | |
4735c98f JD |
706 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
707 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
708 | client->name, client->addr); | |
709 | list_del(&client->detected); | |
710 | i2c_unregister_device(client); | |
711 | } | |
712 | ||
7f101a97 DY |
713 | if (driver->detach_adapter) { |
714 | if (driver->detach_adapter(adapter)) | |
715 | dev_err(&adapter->dev, | |
716 | "detach_adapter failed for driver [%s]\n", | |
717 | driver->driver.name); | |
1da177e4 LT |
718 | } |
719 | ||
7eebcb7c | 720 | return 0; |
1da177e4 LT |
721 | } |
722 | ||
a1d9e6e4 DB |
723 | /** |
724 | * i2c_del_driver - unregister I2C driver | |
725 | * @driver: the driver being unregistered | |
d64f73be | 726 | * Context: can sleep |
a1d9e6e4 | 727 | */ |
b3e82096 | 728 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 729 | { |
caada32a | 730 | mutex_lock(&core_lock); |
93562b53 GKH |
731 | class_for_each_device(&i2c_adapter_class, NULL, driver, |
732 | __detach_adapter); | |
35fc37f8 | 733 | mutex_unlock(&core_lock); |
1da177e4 LT |
734 | |
735 | driver_unregister(&driver->driver); | |
35d8b2e6 | 736 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 737 | } |
c0564606 | 738 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 739 | |
7b4fbc50 DB |
740 | /* ------------------------------------------------------------------------- */ |
741 | ||
9b766b81 | 742 | static int __i2c_check_addr(struct device *dev, void *addrp) |
1da177e4 | 743 | { |
9b766b81 DB |
744 | struct i2c_client *client = i2c_verify_client(dev); |
745 | int addr = *(int *)addrp; | |
1da177e4 | 746 | |
9b766b81 DB |
747 | if (client && client->addr == addr) |
748 | return -EBUSY; | |
1da177e4 LT |
749 | return 0; |
750 | } | |
751 | ||
5e31c2bd | 752 | static int i2c_check_addr(struct i2c_adapter *adapter, int addr) |
1da177e4 | 753 | { |
9b766b81 | 754 | return device_for_each_child(&adapter->dev, &addr, __i2c_check_addr); |
1da177e4 LT |
755 | } |
756 | ||
e48d3319 JD |
757 | /** |
758 | * i2c_use_client - increments the reference count of the i2c client structure | |
759 | * @client: the client being referenced | |
760 | * | |
761 | * Each live reference to a client should be refcounted. The driver model does | |
762 | * that automatically as part of driver binding, so that most drivers don't | |
763 | * need to do this explicitly: they hold a reference until they're unbound | |
764 | * from the device. | |
765 | * | |
766 | * A pointer to the client with the incremented reference counter is returned. | |
767 | */ | |
768 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 769 | { |
6ea438ec DB |
770 | if (client && get_device(&client->dev)) |
771 | return client; | |
772 | return NULL; | |
1da177e4 | 773 | } |
c0564606 | 774 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 775 | |
e48d3319 JD |
776 | /** |
777 | * i2c_release_client - release a use of the i2c client structure | |
778 | * @client: the client being no longer referenced | |
779 | * | |
780 | * Must be called when a user of a client is finished with it. | |
781 | */ | |
782 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 783 | { |
6ea438ec DB |
784 | if (client) |
785 | put_device(&client->dev); | |
1da177e4 | 786 | } |
c0564606 | 787 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 788 | |
9b766b81 DB |
789 | struct i2c_cmd_arg { |
790 | unsigned cmd; | |
791 | void *arg; | |
792 | }; | |
793 | ||
794 | static int i2c_cmd(struct device *dev, void *_arg) | |
795 | { | |
796 | struct i2c_client *client = i2c_verify_client(dev); | |
797 | struct i2c_cmd_arg *arg = _arg; | |
798 | ||
799 | if (client && client->driver && client->driver->command) | |
800 | client->driver->command(client, arg->cmd, arg->arg); | |
801 | return 0; | |
802 | } | |
803 | ||
1da177e4 LT |
804 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
805 | { | |
9b766b81 | 806 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 807 | |
9b766b81 DB |
808 | cmd_arg.cmd = cmd; |
809 | cmd_arg.arg = arg; | |
810 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 811 | } |
c0564606 | 812 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
813 | |
814 | static int __init i2c_init(void) | |
815 | { | |
816 | int retval; | |
817 | ||
818 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
819 | if (retval) |
820 | return retval; | |
e9f1373b DB |
821 | retval = class_register(&i2c_adapter_class); |
822 | if (retval) | |
823 | goto bus_err; | |
824 | retval = i2c_add_driver(&dummy_driver); | |
825 | if (retval) | |
826 | goto class_err; | |
827 | return 0; | |
828 | ||
829 | class_err: | |
830 | class_unregister(&i2c_adapter_class); | |
831 | bus_err: | |
832 | bus_unregister(&i2c_bus_type); | |
833 | return retval; | |
1da177e4 LT |
834 | } |
835 | ||
836 | static void __exit i2c_exit(void) | |
837 | { | |
e9f1373b | 838 | i2c_del_driver(&dummy_driver); |
1da177e4 | 839 | class_unregister(&i2c_adapter_class); |
1da177e4 LT |
840 | bus_unregister(&i2c_bus_type); |
841 | } | |
842 | ||
a10f9e7c DB |
843 | /* We must initialize early, because some subsystems register i2c drivers |
844 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
845 | */ | |
846 | postcore_initcall(i2c_init); | |
1da177e4 LT |
847 | module_exit(i2c_exit); |
848 | ||
849 | /* ---------------------------------------------------- | |
850 | * the functional interface to the i2c busses. | |
851 | * ---------------------------------------------------- | |
852 | */ | |
853 | ||
a1cdedac DB |
854 | /** |
855 | * i2c_transfer - execute a single or combined I2C message | |
856 | * @adap: Handle to I2C bus | |
857 | * @msgs: One or more messages to execute before STOP is issued to | |
858 | * terminate the operation; each message begins with a START. | |
859 | * @num: Number of messages to be executed. | |
860 | * | |
861 | * Returns negative errno, else the number of messages executed. | |
862 | * | |
863 | * Note that there is no requirement that each message be sent to | |
864 | * the same slave address, although that is the most common model. | |
865 | */ | |
09b8ce0a | 866 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 867 | { |
66b650f0 CW |
868 | unsigned long orig_jiffies; |
869 | int ret, try; | |
1da177e4 | 870 | |
a1cdedac DB |
871 | /* REVISIT the fault reporting model here is weak: |
872 | * | |
873 | * - When we get an error after receiving N bytes from a slave, | |
874 | * there is no way to report "N". | |
875 | * | |
876 | * - When we get a NAK after transmitting N bytes to a slave, | |
877 | * there is no way to report "N" ... or to let the master | |
878 | * continue executing the rest of this combined message, if | |
879 | * that's the appropriate response. | |
880 | * | |
881 | * - When for example "num" is two and we successfully complete | |
882 | * the first message but get an error part way through the | |
883 | * second, it's unclear whether that should be reported as | |
884 | * one (discarding status on the second message) or errno | |
885 | * (discarding status on the first one). | |
886 | */ | |
887 | ||
1da177e4 LT |
888 | if (adap->algo->master_xfer) { |
889 | #ifdef DEBUG | |
890 | for (ret = 0; ret < num; ret++) { | |
891 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
892 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
893 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
894 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
895 | } |
896 | #endif | |
897 | ||
cea443a8 MR |
898 | if (in_atomic() || irqs_disabled()) { |
899 | ret = mutex_trylock(&adap->bus_lock); | |
900 | if (!ret) | |
901 | /* I2C activity is ongoing. */ | |
902 | return -EAGAIN; | |
903 | } else { | |
904 | mutex_lock_nested(&adap->bus_lock, adap->level); | |
905 | } | |
906 | ||
66b650f0 CW |
907 | /* Retry automatically on arbitration loss */ |
908 | orig_jiffies = jiffies; | |
909 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
910 | ret = adap->algo->master_xfer(adap, msgs, num); | |
911 | if (ret != -EAGAIN) | |
912 | break; | |
913 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
914 | break; | |
915 | } | |
5c085d36 | 916 | mutex_unlock(&adap->bus_lock); |
1da177e4 LT |
917 | |
918 | return ret; | |
919 | } else { | |
920 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 921 | return -EOPNOTSUPP; |
1da177e4 LT |
922 | } |
923 | } | |
c0564606 | 924 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 925 | |
a1cdedac DB |
926 | /** |
927 | * i2c_master_send - issue a single I2C message in master transmit mode | |
928 | * @client: Handle to slave device | |
929 | * @buf: Data that will be written to the slave | |
930 | * @count: How many bytes to write | |
931 | * | |
932 | * Returns negative errno, or else the number of bytes written. | |
933 | */ | |
1da177e4 LT |
934 | int i2c_master_send(struct i2c_client *client,const char *buf ,int count) |
935 | { | |
936 | int ret; | |
937 | struct i2c_adapter *adap=client->adapter; | |
938 | struct i2c_msg msg; | |
939 | ||
815f55f2 JD |
940 | msg.addr = client->addr; |
941 | msg.flags = client->flags & I2C_M_TEN; | |
942 | msg.len = count; | |
943 | msg.buf = (char *)buf; | |
438d6c2c | 944 | |
815f55f2 | 945 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 946 | |
815f55f2 JD |
947 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes |
948 | transmitted, else error code. */ | |
949 | return (ret == 1) ? count : ret; | |
1da177e4 | 950 | } |
c0564606 | 951 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 952 | |
a1cdedac DB |
953 | /** |
954 | * i2c_master_recv - issue a single I2C message in master receive mode | |
955 | * @client: Handle to slave device | |
956 | * @buf: Where to store data read from slave | |
957 | * @count: How many bytes to read | |
958 | * | |
959 | * Returns negative errno, or else the number of bytes read. | |
960 | */ | |
1da177e4 LT |
961 | int i2c_master_recv(struct i2c_client *client, char *buf ,int count) |
962 | { | |
963 | struct i2c_adapter *adap=client->adapter; | |
964 | struct i2c_msg msg; | |
965 | int ret; | |
815f55f2 JD |
966 | |
967 | msg.addr = client->addr; | |
968 | msg.flags = client->flags & I2C_M_TEN; | |
969 | msg.flags |= I2C_M_RD; | |
970 | msg.len = count; | |
971 | msg.buf = buf; | |
972 | ||
973 | ret = i2c_transfer(adap, &msg, 1); | |
974 | ||
975 | /* If everything went ok (i.e. 1 msg transmitted), return #bytes | |
976 | transmitted, else error code. */ | |
977 | return (ret == 1) ? count : ret; | |
1da177e4 | 978 | } |
c0564606 | 979 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 980 | |
1da177e4 LT |
981 | /* ---------------------------------------------------- |
982 | * the i2c address scanning function | |
983 | * Will not work for 10-bit addresses! | |
984 | * ---------------------------------------------------- | |
985 | */ | |
1da177e4 | 986 | |
4735c98f JD |
987 | static int i2c_detect_address(struct i2c_client *temp_client, int kind, |
988 | struct i2c_driver *driver) | |
989 | { | |
990 | struct i2c_board_info info; | |
991 | struct i2c_adapter *adapter = temp_client->adapter; | |
992 | int addr = temp_client->addr; | |
993 | int err; | |
994 | ||
995 | /* Make sure the address is valid */ | |
996 | if (addr < 0x03 || addr > 0x77) { | |
997 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", | |
998 | addr); | |
999 | return -EINVAL; | |
1000 | } | |
1001 | ||
1002 | /* Skip if already in use */ | |
1003 | if (i2c_check_addr(adapter, addr)) | |
1004 | return 0; | |
1005 | ||
1006 | /* Make sure there is something at this address, unless forced */ | |
1007 | if (kind < 0) { | |
1008 | if (i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1009 | I2C_SMBUS_QUICK, NULL) < 0) | |
1010 | return 0; | |
1011 | ||
1012 | /* prevent 24RF08 corruption */ | |
1013 | if ((addr & ~0x0f) == 0x50) | |
1014 | i2c_smbus_xfer(adapter, addr, 0, 0, 0, | |
1015 | I2C_SMBUS_QUICK, NULL); | |
1016 | } | |
1017 | ||
1018 | /* Finally call the custom detection function */ | |
1019 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1020 | info.addr = addr; | |
1021 | err = driver->detect(temp_client, kind, &info); | |
1022 | if (err) { | |
1023 | /* -ENODEV is returned if the detection fails. We catch it | |
1024 | here as this isn't an error. */ | |
1025 | return err == -ENODEV ? 0 : err; | |
1026 | } | |
1027 | ||
1028 | /* Consistency check */ | |
1029 | if (info.type[0] == '\0') { | |
1030 | dev_err(&adapter->dev, "%s detection function provided " | |
1031 | "no name for 0x%x\n", driver->driver.name, | |
1032 | addr); | |
1033 | } else { | |
1034 | struct i2c_client *client; | |
1035 | ||
1036 | /* Detection succeeded, instantiate the device */ | |
1037 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1038 | info.type, info.addr); | |
1039 | client = i2c_new_device(adapter, &info); | |
1040 | if (client) | |
1041 | list_add_tail(&client->detected, &driver->clients); | |
1042 | else | |
1043 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1044 | info.type, info.addr); | |
1045 | } | |
1046 | return 0; | |
1047 | } | |
1048 | ||
1049 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1050 | { | |
1051 | const struct i2c_client_address_data *address_data; | |
1052 | struct i2c_client *temp_client; | |
1053 | int i, err = 0; | |
1054 | int adap_id = i2c_adapter_id(adapter); | |
1055 | ||
1056 | address_data = driver->address_data; | |
1057 | if (!driver->detect || !address_data) | |
1058 | return 0; | |
1059 | ||
1060 | /* Set up a temporary client to help detect callback */ | |
1061 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1062 | if (!temp_client) | |
1063 | return -ENOMEM; | |
1064 | temp_client->adapter = adapter; | |
1065 | ||
1066 | /* Force entries are done first, and are not affected by ignore | |
1067 | entries */ | |
1068 | if (address_data->forces) { | |
1069 | const unsigned short * const *forces = address_data->forces; | |
1070 | int kind; | |
1071 | ||
1072 | for (kind = 0; forces[kind]; kind++) { | |
1073 | for (i = 0; forces[kind][i] != I2C_CLIENT_END; | |
1074 | i += 2) { | |
1075 | if (forces[kind][i] == adap_id | |
1076 | || forces[kind][i] == ANY_I2C_BUS) { | |
1077 | dev_dbg(&adapter->dev, "found force " | |
1078 | "parameter for adapter %d, " | |
1079 | "addr 0x%02x, kind %d\n", | |
1080 | adap_id, forces[kind][i + 1], | |
1081 | kind); | |
1082 | temp_client->addr = forces[kind][i + 1]; | |
1083 | err = i2c_detect_address(temp_client, | |
1084 | kind, driver); | |
1085 | if (err) | |
1086 | goto exit_free; | |
1087 | } | |
1088 | } | |
1089 | } | |
1090 | } | |
1091 | ||
4329cf86 JD |
1092 | /* Stop here if the classes do not match */ |
1093 | if (!(adapter->class & driver->class)) | |
1094 | goto exit_free; | |
1095 | ||
4735c98f JD |
1096 | /* Stop here if we can't use SMBUS_QUICK */ |
1097 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_QUICK)) { | |
1098 | if (address_data->probe[0] == I2C_CLIENT_END | |
1099 | && address_data->normal_i2c[0] == I2C_CLIENT_END) | |
1100 | goto exit_free; | |
1101 | ||
1102 | dev_warn(&adapter->dev, "SMBus Quick command not supported, " | |
1103 | "can't probe for chips\n"); | |
1104 | err = -EOPNOTSUPP; | |
1105 | goto exit_free; | |
1106 | } | |
1107 | ||
4735c98f JD |
1108 | /* Probe entries are done second, and are not affected by ignore |
1109 | entries either */ | |
1110 | for (i = 0; address_data->probe[i] != I2C_CLIENT_END; i += 2) { | |
1111 | if (address_data->probe[i] == adap_id | |
1112 | || address_data->probe[i] == ANY_I2C_BUS) { | |
1113 | dev_dbg(&adapter->dev, "found probe parameter for " | |
1114 | "adapter %d, addr 0x%02x\n", adap_id, | |
1115 | address_data->probe[i + 1]); | |
1116 | temp_client->addr = address_data->probe[i + 1]; | |
1117 | err = i2c_detect_address(temp_client, -1, driver); | |
1118 | if (err) | |
1119 | goto exit_free; | |
1120 | } | |
1121 | } | |
1122 | ||
1123 | /* Normal entries are done last, unless shadowed by an ignore entry */ | |
1124 | for (i = 0; address_data->normal_i2c[i] != I2C_CLIENT_END; i += 1) { | |
1125 | int j, ignore; | |
1126 | ||
1127 | ignore = 0; | |
1128 | for (j = 0; address_data->ignore[j] != I2C_CLIENT_END; | |
1129 | j += 2) { | |
1130 | if ((address_data->ignore[j] == adap_id || | |
1131 | address_data->ignore[j] == ANY_I2C_BUS) | |
1132 | && address_data->ignore[j + 1] | |
1133 | == address_data->normal_i2c[i]) { | |
1134 | dev_dbg(&adapter->dev, "found ignore " | |
1135 | "parameter for adapter %d, " | |
1136 | "addr 0x%02x\n", adap_id, | |
1137 | address_data->ignore[j + 1]); | |
1138 | ignore = 1; | |
1139 | break; | |
1140 | } | |
1141 | } | |
1142 | if (ignore) | |
1143 | continue; | |
1144 | ||
1145 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " | |
1146 | "addr 0x%02x\n", adap_id, | |
1147 | address_data->normal_i2c[i]); | |
1148 | temp_client->addr = address_data->normal_i2c[i]; | |
1149 | err = i2c_detect_address(temp_client, -1, driver); | |
1150 | if (err) | |
1151 | goto exit_free; | |
1152 | } | |
1153 | ||
1154 | exit_free: | |
1155 | kfree(temp_client); | |
1156 | return err; | |
1157 | } | |
1158 | ||
12b5053a JD |
1159 | struct i2c_client * |
1160 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1161 | struct i2c_board_info *info, | |
1162 | unsigned short const *addr_list) | |
1163 | { | |
1164 | int i; | |
1165 | ||
1166 | /* Stop here if the bus doesn't support probing */ | |
1167 | if (!i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) { | |
1168 | dev_err(&adap->dev, "Probing not supported\n"); | |
1169 | return NULL; | |
1170 | } | |
1171 | ||
12b5053a JD |
1172 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1173 | /* Check address validity */ | |
1174 | if (addr_list[i] < 0x03 || addr_list[i] > 0x77) { | |
1175 | dev_warn(&adap->dev, "Invalid 7-bit address " | |
1176 | "0x%02x\n", addr_list[i]); | |
1177 | continue; | |
1178 | } | |
1179 | ||
1180 | /* Check address availability */ | |
9b766b81 | 1181 | if (i2c_check_addr(adap, addr_list[i])) { |
12b5053a JD |
1182 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1183 | "use, not probing\n", addr_list[i]); | |
1184 | continue; | |
1185 | } | |
1186 | ||
1187 | /* Test address responsiveness | |
1188 | The default probe method is a quick write, but it is known | |
1189 | to corrupt the 24RF08 EEPROMs due to a state machine bug, | |
1190 | and could also irreversibly write-protect some EEPROMs, so | |
1191 | for address ranges 0x30-0x37 and 0x50-0x5f, we use a byte | |
1192 | read instead. Also, some bus drivers don't implement | |
1193 | quick write, so we fallback to a byte read it that case | |
1194 | too. */ | |
1195 | if ((addr_list[i] & ~0x07) == 0x30 | |
1196 | || (addr_list[i] & ~0x0f) == 0x50 | |
1197 | || !i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) { | |
b25b791b HV |
1198 | union i2c_smbus_data data; |
1199 | ||
12b5053a JD |
1200 | if (i2c_smbus_xfer(adap, addr_list[i], 0, |
1201 | I2C_SMBUS_READ, 0, | |
b25b791b | 1202 | I2C_SMBUS_BYTE, &data) >= 0) |
12b5053a JD |
1203 | break; |
1204 | } else { | |
1205 | if (i2c_smbus_xfer(adap, addr_list[i], 0, | |
1206 | I2C_SMBUS_WRITE, 0, | |
1207 | I2C_SMBUS_QUICK, NULL) >= 0) | |
1208 | break; | |
1209 | } | |
1210 | } | |
12b5053a JD |
1211 | |
1212 | if (addr_list[i] == I2C_CLIENT_END) { | |
1213 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1214 | return NULL; | |
1215 | } | |
1216 | ||
1217 | info->addr = addr_list[i]; | |
1218 | return i2c_new_device(adap, info); | |
1219 | } | |
1220 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1221 | ||
1da177e4 LT |
1222 | struct i2c_adapter* i2c_get_adapter(int id) |
1223 | { | |
1da177e4 | 1224 | struct i2c_adapter *adapter; |
438d6c2c | 1225 | |
caada32a | 1226 | mutex_lock(&core_lock); |
1cf92b45 | 1227 | adapter = idr_find(&i2c_adapter_idr, id); |
a0920e10 MH |
1228 | if (adapter && !try_module_get(adapter->owner)) |
1229 | adapter = NULL; | |
1230 | ||
caada32a | 1231 | mutex_unlock(&core_lock); |
a0920e10 | 1232 | return adapter; |
1da177e4 | 1233 | } |
c0564606 | 1234 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1235 | |
1236 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1237 | { | |
1238 | module_put(adap->owner); | |
1239 | } | |
c0564606 | 1240 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1241 | |
1242 | /* The SMBus parts */ | |
1243 | ||
438d6c2c | 1244 | #define POLY (0x1070U << 3) |
09b8ce0a | 1245 | static u8 crc8(u16 data) |
1da177e4 LT |
1246 | { |
1247 | int i; | |
438d6c2c | 1248 | |
1da177e4 | 1249 | for(i = 0; i < 8; i++) { |
438d6c2c | 1250 | if (data & 0x8000) |
1da177e4 LT |
1251 | data = data ^ POLY; |
1252 | data = data << 1; | |
1253 | } | |
1254 | return (u8)(data >> 8); | |
1255 | } | |
1256 | ||
421ef47b JD |
1257 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1258 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1259 | { |
1260 | int i; | |
1261 | ||
1262 | for(i = 0; i < count; i++) | |
421ef47b | 1263 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1264 | return crc; |
1265 | } | |
1266 | ||
421ef47b JD |
1267 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1268 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1269 | { |
421ef47b JD |
1270 | /* The address will be sent first */ |
1271 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1272 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1273 | ||
1274 | /* The data buffer follows */ | |
1275 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1276 | } |
1277 | ||
421ef47b JD |
1278 | /* Used for write only transactions */ |
1279 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1280 | { |
421ef47b JD |
1281 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1282 | msg->len++; | |
1da177e4 LT |
1283 | } |
1284 | ||
421ef47b JD |
1285 | /* Return <0 on CRC error |
1286 | If there was a write before this read (most cases) we need to take the | |
1287 | partial CRC from the write part into account. | |
1288 | Note that this function does modify the message (we need to decrease the | |
1289 | message length to hide the CRC byte from the caller). */ | |
1290 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1291 | { |
421ef47b JD |
1292 | u8 rpec = msg->buf[--msg->len]; |
1293 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1294 | |
1da177e4 LT |
1295 | if (rpec != cpec) { |
1296 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1297 | rpec, cpec); | |
24a5bb7b | 1298 | return -EBADMSG; |
1da177e4 | 1299 | } |
438d6c2c | 1300 | return 0; |
1da177e4 LT |
1301 | } |
1302 | ||
a1cdedac DB |
1303 | /** |
1304 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1305 | * @client: Handle to slave device | |
1306 | * | |
1307 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1308 | * else the byte received from the device. | |
1309 | */ | |
1da177e4 LT |
1310 | s32 i2c_smbus_read_byte(struct i2c_client *client) |
1311 | { | |
1312 | union i2c_smbus_data data; | |
24a5bb7b DB |
1313 | int status; |
1314 | ||
1315 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1316 | I2C_SMBUS_READ, 0, | |
1317 | I2C_SMBUS_BYTE, &data); | |
1318 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1319 | } |
c0564606 | 1320 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1321 | |
a1cdedac DB |
1322 | /** |
1323 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1324 | * @client: Handle to slave device | |
1325 | * @value: Byte to be sent | |
1326 | * | |
1327 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1328 | * else zero on success. | |
1329 | */ | |
1da177e4 LT |
1330 | s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value) |
1331 | { | |
1da177e4 | 1332 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
421ef47b | 1333 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1334 | } |
c0564606 | 1335 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1336 | |
a1cdedac DB |
1337 | /** |
1338 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1339 | * @client: Handle to slave device | |
1340 | * @command: Byte interpreted by slave | |
1341 | * | |
1342 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1343 | * else a data byte received from the device. | |
1344 | */ | |
1da177e4 LT |
1345 | s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command) |
1346 | { | |
1347 | union i2c_smbus_data data; | |
24a5bb7b DB |
1348 | int status; |
1349 | ||
1350 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1351 | I2C_SMBUS_READ, command, | |
1352 | I2C_SMBUS_BYTE_DATA, &data); | |
1353 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1354 | } |
c0564606 | 1355 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1356 | |
a1cdedac DB |
1357 | /** |
1358 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1359 | * @client: Handle to slave device | |
1360 | * @command: Byte interpreted by slave | |
1361 | * @value: Byte being written | |
1362 | * | |
1363 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1364 | * else zero on success. | |
1365 | */ | |
1da177e4 LT |
1366 | s32 i2c_smbus_write_byte_data(struct i2c_client *client, u8 command, u8 value) |
1367 | { | |
1368 | union i2c_smbus_data data; | |
1369 | data.byte = value; | |
1370 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1371 | I2C_SMBUS_WRITE,command, | |
1372 | I2C_SMBUS_BYTE_DATA,&data); | |
1373 | } | |
c0564606 | 1374 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1375 | |
a1cdedac DB |
1376 | /** |
1377 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1378 | * @client: Handle to slave device | |
1379 | * @command: Byte interpreted by slave | |
1380 | * | |
1381 | * This executes the SMBus "read word" protocol, returning negative errno | |
1382 | * else a 16-bit unsigned "word" received from the device. | |
1383 | */ | |
1da177e4 LT |
1384 | s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command) |
1385 | { | |
1386 | union i2c_smbus_data data; | |
24a5bb7b DB |
1387 | int status; |
1388 | ||
1389 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1390 | I2C_SMBUS_READ, command, | |
1391 | I2C_SMBUS_WORD_DATA, &data); | |
1392 | return (status < 0) ? status : data.word; | |
1da177e4 | 1393 | } |
c0564606 | 1394 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1395 | |
a1cdedac DB |
1396 | /** |
1397 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1398 | * @client: Handle to slave device | |
1399 | * @command: Byte interpreted by slave | |
1400 | * @value: 16-bit "word" being written | |
1401 | * | |
1402 | * This executes the SMBus "write word" protocol, returning negative errno | |
1403 | * else zero on success. | |
1404 | */ | |
1da177e4 LT |
1405 | s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value) |
1406 | { | |
1407 | union i2c_smbus_data data; | |
1408 | data.word = value; | |
1409 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, | |
1410 | I2C_SMBUS_WRITE,command, | |
1411 | I2C_SMBUS_WORD_DATA,&data); | |
1412 | } | |
c0564606 | 1413 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1414 | |
596c88f4 PM |
1415 | /** |
1416 | * i2c_smbus_process_call - SMBus "process call" protocol | |
1417 | * @client: Handle to slave device | |
1418 | * @command: Byte interpreted by slave | |
1419 | * @value: 16-bit "word" being written | |
1420 | * | |
1421 | * This executes the SMBus "process call" protocol, returning negative errno | |
1422 | * else a 16-bit unsigned "word" received from the device. | |
1423 | */ | |
1424 | s32 i2c_smbus_process_call(struct i2c_client *client, u8 command, u16 value) | |
1425 | { | |
1426 | union i2c_smbus_data data; | |
1427 | int status; | |
1428 | data.word = value; | |
1429 | ||
1430 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1431 | I2C_SMBUS_WRITE, command, | |
1432 | I2C_SMBUS_PROC_CALL, &data); | |
1433 | return (status < 0) ? status : data.word; | |
1434 | } | |
1435 | EXPORT_SYMBOL(i2c_smbus_process_call); | |
1436 | ||
a64ec07d | 1437 | /** |
a1cdedac | 1438 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1439 | * @client: Handle to slave device |
a1cdedac | 1440 | * @command: Byte interpreted by slave |
a64ec07d DB |
1441 | * @values: Byte array into which data will be read; big enough to hold |
1442 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1443 | * | |
a1cdedac DB |
1444 | * This executes the SMBus "block read" protocol, returning negative errno |
1445 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1446 | * |
1447 | * Note that using this function requires that the client's adapter support | |
1448 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1449 | * support this; its emulation through I2C messaging relies on a specific | |
1450 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1451 | */ | |
b86a1bc8 JD |
1452 | s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, |
1453 | u8 *values) | |
1454 | { | |
1455 | union i2c_smbus_data data; | |
24a5bb7b | 1456 | int status; |
b86a1bc8 | 1457 | |
24a5bb7b DB |
1458 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1459 | I2C_SMBUS_READ, command, | |
1460 | I2C_SMBUS_BLOCK_DATA, &data); | |
1461 | if (status) | |
1462 | return status; | |
b86a1bc8 JD |
1463 | |
1464 | memcpy(values, &data.block[1], data.block[0]); | |
1465 | return data.block[0]; | |
1466 | } | |
1467 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1468 | ||
a1cdedac DB |
1469 | /** |
1470 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1471 | * @client: Handle to slave device | |
1472 | * @command: Byte interpreted by slave | |
1473 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1474 | * @values: Byte array which will be written. | |
1475 | * | |
1476 | * This executes the SMBus "block write" protocol, returning negative errno | |
1477 | * else zero on success. | |
1478 | */ | |
1da177e4 | 1479 | s32 i2c_smbus_write_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1480 | u8 length, const u8 *values) |
1da177e4 LT |
1481 | { |
1482 | union i2c_smbus_data data; | |
7656032b | 1483 | |
1da177e4 LT |
1484 | if (length > I2C_SMBUS_BLOCK_MAX) |
1485 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1486 | data.block[0] = length; |
7656032b | 1487 | memcpy(&data.block[1], values, length); |
1da177e4 LT |
1488 | return i2c_smbus_xfer(client->adapter,client->addr,client->flags, |
1489 | I2C_SMBUS_WRITE,command, | |
1490 | I2C_SMBUS_BLOCK_DATA,&data); | |
1491 | } | |
c0564606 | 1492 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1493 | |
1494 | /* Returns the number of read bytes */ | |
4b2643d7 JD |
1495 | s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, u8 command, |
1496 | u8 length, u8 *values) | |
1da177e4 LT |
1497 | { |
1498 | union i2c_smbus_data data; | |
24a5bb7b | 1499 | int status; |
7656032b | 1500 | |
4b2643d7 JD |
1501 | if (length > I2C_SMBUS_BLOCK_MAX) |
1502 | length = I2C_SMBUS_BLOCK_MAX; | |
1503 | data.block[0] = length; | |
24a5bb7b DB |
1504 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1505 | I2C_SMBUS_READ, command, | |
1506 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1507 | if (status < 0) | |
1508 | return status; | |
7656032b JD |
1509 | |
1510 | memcpy(values, &data.block[1], data.block[0]); | |
1511 | return data.block[0]; | |
1da177e4 | 1512 | } |
c0564606 | 1513 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1514 | |
21bbd691 | 1515 | s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, u8 command, |
46f5ed75 | 1516 | u8 length, const u8 *values) |
21bbd691 JD |
1517 | { |
1518 | union i2c_smbus_data data; | |
1519 | ||
1520 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1521 | length = I2C_SMBUS_BLOCK_MAX; | |
1522 | data.block[0] = length; | |
1523 | memcpy(data.block + 1, values, length); | |
1524 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1525 | I2C_SMBUS_WRITE, command, | |
1526 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1527 | } | |
c0564606 | 1528 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1529 | |
438d6c2c | 1530 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1531 | No checking of parameters is done! */ |
438d6c2c | 1532 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter * adapter, u16 addr, |
1da177e4 | 1533 | unsigned short flags, |
438d6c2c | 1534 | char read_write, u8 command, int size, |
1da177e4 LT |
1535 | union i2c_smbus_data * data) |
1536 | { | |
1537 | /* So we need to generate a series of msgs. In the case of writing, we | |
1538 | need to use only one message; when reading, we need two. We initialize | |
1539 | most things with sane defaults, to keep the code below somewhat | |
1540 | simpler. */ | |
5c50d188 HI |
1541 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1542 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
1da177e4 | 1543 | int num = read_write == I2C_SMBUS_READ?2:1; |
438d6c2c | 1544 | struct i2c_msg msg[2] = { { addr, flags, 1, msgbuf0 }, |
1da177e4 LT |
1545 | { addr, flags | I2C_M_RD, 0, msgbuf1 } |
1546 | }; | |
1547 | int i; | |
421ef47b | 1548 | u8 partial_pec = 0; |
24a5bb7b | 1549 | int status; |
1da177e4 LT |
1550 | |
1551 | msgbuf0[0] = command; | |
1552 | switch(size) { | |
1553 | case I2C_SMBUS_QUICK: | |
1554 | msg[0].len = 0; | |
1555 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1556 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1557 | I2C_M_RD : 0); | |
1da177e4 LT |
1558 | num = 1; |
1559 | break; | |
1560 | case I2C_SMBUS_BYTE: | |
1561 | if (read_write == I2C_SMBUS_READ) { | |
1562 | /* Special case: only a read! */ | |
1563 | msg[0].flags = I2C_M_RD | flags; | |
1564 | num = 1; | |
1565 | } | |
1566 | break; | |
1567 | case I2C_SMBUS_BYTE_DATA: | |
1568 | if (read_write == I2C_SMBUS_READ) | |
1569 | msg[1].len = 1; | |
1570 | else { | |
1571 | msg[0].len = 2; | |
1572 | msgbuf0[1] = data->byte; | |
1573 | } | |
1574 | break; | |
1575 | case I2C_SMBUS_WORD_DATA: | |
1576 | if (read_write == I2C_SMBUS_READ) | |
1577 | msg[1].len = 2; | |
1578 | else { | |
1579 | msg[0].len=3; | |
1580 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1581 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1582 | } |
1583 | break; | |
1584 | case I2C_SMBUS_PROC_CALL: | |
1585 | num = 2; /* Special case */ | |
1586 | read_write = I2C_SMBUS_READ; | |
1587 | msg[0].len = 3; | |
1588 | msg[1].len = 2; | |
1589 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 1590 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
1591 | break; |
1592 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 1593 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
1594 | msg[1].flags |= I2C_M_RECV_LEN; |
1595 | msg[1].len = 1; /* block length will be added by | |
1596 | the underlying bus driver */ | |
1da177e4 LT |
1597 | } else { |
1598 | msg[0].len = data->block[0] + 2; | |
1599 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
1600 | dev_err(&adapter->dev, |
1601 | "Invalid block write size %d\n", | |
1602 | data->block[0]); | |
1603 | return -EINVAL; | |
1da177e4 | 1604 | } |
5c50d188 | 1605 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
1606 | msgbuf0[i] = data->block[i-1]; |
1607 | } | |
1608 | break; | |
1609 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
1610 | num = 2; /* Another special case */ |
1611 | read_write = I2C_SMBUS_READ; | |
1612 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
1613 | dev_err(&adapter->dev, |
1614 | "Invalid block write size %d\n", | |
209d27c3 | 1615 | data->block[0]); |
24a5bb7b | 1616 | return -EINVAL; |
209d27c3 JD |
1617 | } |
1618 | msg[0].len = data->block[0] + 2; | |
1619 | for (i = 1; i < msg[0].len; i++) | |
1620 | msgbuf0[i] = data->block[i-1]; | |
1621 | msg[1].flags |= I2C_M_RECV_LEN; | |
1622 | msg[1].len = 1; /* block length will be added by | |
1623 | the underlying bus driver */ | |
1624 | break; | |
1da177e4 LT |
1625 | case I2C_SMBUS_I2C_BLOCK_DATA: |
1626 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 1627 | msg[1].len = data->block[0]; |
1da177e4 LT |
1628 | } else { |
1629 | msg[0].len = data->block[0] + 1; | |
30dac746 | 1630 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
1631 | dev_err(&adapter->dev, |
1632 | "Invalid block write size %d\n", | |
1633 | data->block[0]); | |
1634 | return -EINVAL; | |
1da177e4 LT |
1635 | } |
1636 | for (i = 1; i <= data->block[0]; i++) | |
1637 | msgbuf0[i] = data->block[i]; | |
1638 | } | |
1639 | break; | |
1640 | default: | |
24a5bb7b DB |
1641 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
1642 | return -EOPNOTSUPP; | |
1da177e4 LT |
1643 | } |
1644 | ||
421ef47b JD |
1645 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
1646 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
1647 | if (i) { | |
1648 | /* Compute PEC if first message is a write */ | |
1649 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 1650 | if (num == 1) /* Write only */ |
421ef47b JD |
1651 | i2c_smbus_add_pec(&msg[0]); |
1652 | else /* Write followed by read */ | |
1653 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
1654 | } | |
1655 | /* Ask for PEC if last message is a read */ | |
1656 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 1657 | msg[num-1].len++; |
421ef47b JD |
1658 | } |
1659 | ||
24a5bb7b DB |
1660 | status = i2c_transfer(adapter, msg, num); |
1661 | if (status < 0) | |
1662 | return status; | |
1da177e4 | 1663 | |
421ef47b JD |
1664 | /* Check PEC if last message is a read */ |
1665 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
1666 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
1667 | if (status < 0) | |
1668 | return status; | |
421ef47b JD |
1669 | } |
1670 | ||
1da177e4 LT |
1671 | if (read_write == I2C_SMBUS_READ) |
1672 | switch(size) { | |
1673 | case I2C_SMBUS_BYTE: | |
1674 | data->byte = msgbuf0[0]; | |
1675 | break; | |
1676 | case I2C_SMBUS_BYTE_DATA: | |
1677 | data->byte = msgbuf1[0]; | |
1678 | break; | |
438d6c2c | 1679 | case I2C_SMBUS_WORD_DATA: |
1da177e4 LT |
1680 | case I2C_SMBUS_PROC_CALL: |
1681 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
1682 | break; | |
1683 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
4b2643d7 | 1684 | for (i = 0; i < data->block[0]; i++) |
1da177e4 LT |
1685 | data->block[i+1] = msgbuf1[i]; |
1686 | break; | |
209d27c3 JD |
1687 | case I2C_SMBUS_BLOCK_DATA: |
1688 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
1689 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
1690 | data->block[i] = msgbuf1[i]; | |
1691 | break; | |
1da177e4 LT |
1692 | } |
1693 | return 0; | |
1694 | } | |
1695 | ||
a1cdedac DB |
1696 | /** |
1697 | * i2c_smbus_xfer - execute SMBus protocol operations | |
1698 | * @adapter: Handle to I2C bus | |
1699 | * @addr: Address of SMBus slave on that bus | |
1700 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
1701 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
1702 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
1703 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
1704 | * @data: Data to be read or written | |
1705 | * | |
1706 | * This executes an SMBus protocol operation, and returns a negative | |
1707 | * errno code else zero on success. | |
1708 | */ | |
09b8ce0a | 1709 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 1710 | char read_write, u8 command, int protocol, |
09b8ce0a | 1711 | union i2c_smbus_data *data) |
1da177e4 | 1712 | { |
66b650f0 CW |
1713 | unsigned long orig_jiffies; |
1714 | int try; | |
1da177e4 | 1715 | s32 res; |
1da177e4 LT |
1716 | |
1717 | flags &= I2C_M_TEN | I2C_CLIENT_PEC; | |
1da177e4 LT |
1718 | |
1719 | if (adapter->algo->smbus_xfer) { | |
5c085d36 | 1720 | mutex_lock(&adapter->bus_lock); |
66b650f0 CW |
1721 | |
1722 | /* Retry automatically on arbitration loss */ | |
1723 | orig_jiffies = jiffies; | |
1724 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
1725 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
1726 | read_write, command, | |
1727 | protocol, data); | |
1728 | if (res != -EAGAIN) | |
1729 | break; | |
1730 | if (time_after(jiffies, | |
1731 | orig_jiffies + adapter->timeout)) | |
1732 | break; | |
1733 | } | |
5c085d36 | 1734 | mutex_unlock(&adapter->bus_lock); |
1da177e4 LT |
1735 | } else |
1736 | res = i2c_smbus_xfer_emulated(adapter,addr,flags,read_write, | |
a1cdedac | 1737 | command, protocol, data); |
1da177e4 | 1738 | |
1da177e4 LT |
1739 | return res; |
1740 | } | |
1da177e4 | 1741 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
1742 | |
1743 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
1744 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
1745 | MODULE_LICENSE("GPL"); |