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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 | |
5694f8a8 JD |
17 | Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
18 | MA 02110-1301 USA. */ | |
1da177e4 LT |
19 | /* ------------------------------------------------------------------------- */ |
20 | ||
96de0e25 | 21 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi>. |
1da177e4 | 22 | All SMBus-related things are written by Frodo Looijaard <frodol@dds.nl> |
421ef47b | 23 | SMBus 2.0 support by Mark Studebaker <mdsxyz123@yahoo.com> and |
0826374b ML |
24 | Jean Delvare <khali@linux-fr.org> |
25 | Mux support by Rodolfo Giometti <giometti@enneenne.com> and | |
26 | Michael Lawnick <michael.lawnick.ext@nsn.com> */ | |
1da177e4 | 27 | |
1da177e4 LT |
28 | #include <linux/module.h> |
29 | #include <linux/kernel.h> | |
30 | #include <linux/errno.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/i2c.h> | |
33 | #include <linux/init.h> | |
34 | #include <linux/idr.h> | |
b3585e4f | 35 | #include <linux/mutex.h> |
959e85f7 | 36 | #include <linux/of_device.h> |
b8d6f45b | 37 | #include <linux/completion.h> |
cea443a8 MR |
38 | #include <linux/hardirq.h> |
39 | #include <linux/irqflags.h> | |
f18c41da | 40 | #include <linux/rwsem.h> |
6de468ae | 41 | #include <linux/pm_runtime.h> |
907ddf89 | 42 | #include <linux/acpi.h> |
1da177e4 LT |
43 | #include <asm/uaccess.h> |
44 | ||
9c1600ed DB |
45 | #include "i2c-core.h" |
46 | ||
1da177e4 | 47 | |
6629dcff | 48 | /* core_lock protects i2c_adapter_idr, and guarantees |
35fc37f8 JD |
49 | that device detection, deletion of detected devices, and attach_adapter |
50 | and detach_adapter calls are serialized */ | |
caada32a | 51 | static DEFINE_MUTEX(core_lock); |
1da177e4 LT |
52 | static DEFINE_IDR(i2c_adapter_idr); |
53 | ||
4f8cf824 | 54 | static struct device_type i2c_client_type; |
4735c98f | 55 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver); |
f37dd80a DB |
56 | |
57 | /* ------------------------------------------------------------------------- */ | |
58 | ||
d2653e92 JD |
59 | static const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, |
60 | const struct i2c_client *client) | |
61 | { | |
62 | while (id->name[0]) { | |
63 | if (strcmp(client->name, id->name) == 0) | |
64 | return id; | |
65 | id++; | |
66 | } | |
67 | return NULL; | |
68 | } | |
69 | ||
1da177e4 LT |
70 | static int i2c_device_match(struct device *dev, struct device_driver *drv) |
71 | { | |
51298d12 JD |
72 | struct i2c_client *client = i2c_verify_client(dev); |
73 | struct i2c_driver *driver; | |
74 | ||
75 | if (!client) | |
76 | return 0; | |
7b4fbc50 | 77 | |
959e85f7 GL |
78 | /* Attempt an OF style match */ |
79 | if (of_driver_match_device(dev, drv)) | |
80 | return 1; | |
81 | ||
907ddf89 MW |
82 | /* Then ACPI style match */ |
83 | if (acpi_driver_match_device(dev, drv)) | |
84 | return 1; | |
85 | ||
51298d12 | 86 | driver = to_i2c_driver(drv); |
d2653e92 JD |
87 | /* match on an id table if there is one */ |
88 | if (driver->id_table) | |
89 | return i2c_match_id(driver->id_table, client) != NULL; | |
90 | ||
eb8a7908 | 91 | return 0; |
1da177e4 LT |
92 | } |
93 | ||
7b4fbc50 DB |
94 | #ifdef CONFIG_HOTPLUG |
95 | ||
96 | /* uevent helps with hotplug: modprobe -q $(MODALIAS) */ | |
7eff2e7a | 97 | static int i2c_device_uevent(struct device *dev, struct kobj_uevent_env *env) |
7b4fbc50 DB |
98 | { |
99 | struct i2c_client *client = to_i2c_client(dev); | |
7b4fbc50 | 100 | |
eb8a7908 JD |
101 | if (add_uevent_var(env, "MODALIAS=%s%s", |
102 | I2C_MODULE_PREFIX, client->name)) | |
103 | return -ENOMEM; | |
7b4fbc50 DB |
104 | dev_dbg(dev, "uevent\n"); |
105 | return 0; | |
106 | } | |
107 | ||
108 | #else | |
109 | #define i2c_device_uevent NULL | |
110 | #endif /* CONFIG_HOTPLUG */ | |
111 | ||
f37dd80a | 112 | static int i2c_device_probe(struct device *dev) |
1da177e4 | 113 | { |
51298d12 JD |
114 | struct i2c_client *client = i2c_verify_client(dev); |
115 | struct i2c_driver *driver; | |
50c3304a | 116 | int status; |
7b4fbc50 | 117 | |
51298d12 JD |
118 | if (!client) |
119 | return 0; | |
120 | ||
121 | driver = to_i2c_driver(dev->driver); | |
e0457442 | 122 | if (!driver->probe || !driver->id_table) |
7b4fbc50 DB |
123 | return -ENODEV; |
124 | client->driver = driver; | |
ee35425c MP |
125 | if (!device_can_wakeup(&client->dev)) |
126 | device_init_wakeup(&client->dev, | |
127 | client->flags & I2C_CLIENT_WAKE); | |
7b4fbc50 | 128 | dev_dbg(dev, "probe\n"); |
d2653e92 | 129 | |
e0457442 | 130 | status = driver->probe(client, i2c_match_id(driver->id_table, client)); |
e4a7b9b0 | 131 | if (status) { |
50c3304a | 132 | client->driver = NULL; |
e4a7b9b0 WS |
133 | i2c_set_clientdata(client, NULL); |
134 | } | |
50c3304a | 135 | return status; |
f37dd80a | 136 | } |
1da177e4 | 137 | |
f37dd80a DB |
138 | static int i2c_device_remove(struct device *dev) |
139 | { | |
51298d12 | 140 | struct i2c_client *client = i2c_verify_client(dev); |
a1d9e6e4 DB |
141 | struct i2c_driver *driver; |
142 | int status; | |
143 | ||
51298d12 | 144 | if (!client || !dev->driver) |
a1d9e6e4 DB |
145 | return 0; |
146 | ||
147 | driver = to_i2c_driver(dev->driver); | |
148 | if (driver->remove) { | |
149 | dev_dbg(dev, "remove\n"); | |
150 | status = driver->remove(client); | |
151 | } else { | |
152 | dev->driver = NULL; | |
153 | status = 0; | |
154 | } | |
e4a7b9b0 | 155 | if (status == 0) { |
a1d9e6e4 | 156 | client->driver = NULL; |
e4a7b9b0 WS |
157 | i2c_set_clientdata(client, NULL); |
158 | } | |
a1d9e6e4 | 159 | return status; |
1da177e4 LT |
160 | } |
161 | ||
f37dd80a | 162 | static void i2c_device_shutdown(struct device *dev) |
1da177e4 | 163 | { |
51298d12 | 164 | struct i2c_client *client = i2c_verify_client(dev); |
f37dd80a DB |
165 | struct i2c_driver *driver; |
166 | ||
51298d12 | 167 | if (!client || !dev->driver) |
f37dd80a DB |
168 | return; |
169 | driver = to_i2c_driver(dev->driver); | |
170 | if (driver->shutdown) | |
51298d12 | 171 | driver->shutdown(client); |
1da177e4 LT |
172 | } |
173 | ||
2f60ba70 RW |
174 | #ifdef CONFIG_PM_SLEEP |
175 | static int i2c_legacy_suspend(struct device *dev, pm_message_t mesg) | |
54067ee2 | 176 | { |
2f60ba70 RW |
177 | struct i2c_client *client = i2c_verify_client(dev); |
178 | struct i2c_driver *driver; | |
54067ee2 | 179 | |
2f60ba70 | 180 | if (!client || !dev->driver) |
54067ee2 | 181 | return 0; |
2f60ba70 RW |
182 | driver = to_i2c_driver(dev->driver); |
183 | if (!driver->suspend) | |
54067ee2 | 184 | return 0; |
2f60ba70 | 185 | return driver->suspend(client, mesg); |
54067ee2 | 186 | } |
187 | ||
2f60ba70 | 188 | static int i2c_legacy_resume(struct device *dev) |
54067ee2 | 189 | { |
2f60ba70 RW |
190 | struct i2c_client *client = i2c_verify_client(dev); |
191 | struct i2c_driver *driver; | |
54067ee2 | 192 | |
2f60ba70 | 193 | if (!client || !dev->driver) |
54067ee2 | 194 | return 0; |
2f60ba70 RW |
195 | driver = to_i2c_driver(dev->driver); |
196 | if (!driver->resume) | |
54067ee2 | 197 | return 0; |
2f60ba70 | 198 | return driver->resume(client); |
54067ee2 | 199 | } |
54067ee2 | 200 | |
2f60ba70 | 201 | static int i2c_device_pm_suspend(struct device *dev) |
6de468ae | 202 | { |
2f60ba70 | 203 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 204 | |
d529de29 MB |
205 | if (pm) |
206 | return pm_generic_suspend(dev); | |
207 | else | |
208 | return i2c_legacy_suspend(dev, PMSG_SUSPEND); | |
6de468ae MB |
209 | } |
210 | ||
2f60ba70 | 211 | static int i2c_device_pm_resume(struct device *dev) |
6de468ae | 212 | { |
2f60ba70 | 213 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
6de468ae | 214 | |
2f60ba70 | 215 | if (pm) |
d529de29 | 216 | return pm_generic_resume(dev); |
2f60ba70 | 217 | else |
d529de29 | 218 | return i2c_legacy_resume(dev); |
6de468ae | 219 | } |
6de468ae | 220 | |
2f60ba70 | 221 | static int i2c_device_pm_freeze(struct device *dev) |
1da177e4 | 222 | { |
2f60ba70 | 223 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 224 | |
d529de29 MB |
225 | if (pm) |
226 | return pm_generic_freeze(dev); | |
227 | else | |
228 | return i2c_legacy_suspend(dev, PMSG_FREEZE); | |
1da177e4 LT |
229 | } |
230 | ||
2f60ba70 | 231 | static int i2c_device_pm_thaw(struct device *dev) |
1da177e4 | 232 | { |
2f60ba70 | 233 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; |
f37dd80a | 234 | |
d529de29 MB |
235 | if (pm) |
236 | return pm_generic_thaw(dev); | |
237 | else | |
238 | return i2c_legacy_resume(dev); | |
2f60ba70 RW |
239 | } |
240 | ||
241 | static int i2c_device_pm_poweroff(struct device *dev) | |
242 | { | |
243 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
244 | ||
d529de29 MB |
245 | if (pm) |
246 | return pm_generic_poweroff(dev); | |
247 | else | |
248 | return i2c_legacy_suspend(dev, PMSG_HIBERNATE); | |
2f60ba70 RW |
249 | } |
250 | ||
251 | static int i2c_device_pm_restore(struct device *dev) | |
252 | { | |
253 | const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL; | |
2f60ba70 RW |
254 | |
255 | if (pm) | |
d529de29 | 256 | return pm_generic_restore(dev); |
2f60ba70 | 257 | else |
d529de29 | 258 | return i2c_legacy_resume(dev); |
1da177e4 | 259 | } |
2f60ba70 RW |
260 | #else /* !CONFIG_PM_SLEEP */ |
261 | #define i2c_device_pm_suspend NULL | |
262 | #define i2c_device_pm_resume NULL | |
263 | #define i2c_device_pm_freeze NULL | |
264 | #define i2c_device_pm_thaw NULL | |
265 | #define i2c_device_pm_poweroff NULL | |
266 | #define i2c_device_pm_restore NULL | |
267 | #endif /* !CONFIG_PM_SLEEP */ | |
1da177e4 | 268 | |
9c1600ed DB |
269 | static void i2c_client_dev_release(struct device *dev) |
270 | { | |
271 | kfree(to_i2c_client(dev)); | |
272 | } | |
273 | ||
09b8ce0a | 274 | static ssize_t |
4f8cf824 | 275 | show_name(struct device *dev, struct device_attribute *attr, char *buf) |
7b4fbc50 | 276 | { |
4f8cf824 JD |
277 | return sprintf(buf, "%s\n", dev->type == &i2c_client_type ? |
278 | to_i2c_client(dev)->name : to_i2c_adapter(dev)->name); | |
7b4fbc50 DB |
279 | } |
280 | ||
09b8ce0a ZX |
281 | static ssize_t |
282 | show_modalias(struct device *dev, struct device_attribute *attr, char *buf) | |
7b4fbc50 DB |
283 | { |
284 | struct i2c_client *client = to_i2c_client(dev); | |
eb8a7908 | 285 | return sprintf(buf, "%s%s\n", I2C_MODULE_PREFIX, client->name); |
7b4fbc50 DB |
286 | } |
287 | ||
4f8cf824 | 288 | static DEVICE_ATTR(name, S_IRUGO, show_name, NULL); |
51298d12 JD |
289 | static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL); |
290 | ||
291 | static struct attribute *i2c_dev_attrs[] = { | |
292 | &dev_attr_name.attr, | |
7b4fbc50 | 293 | /* modalias helps coldplug: modprobe $(cat .../modalias) */ |
51298d12 JD |
294 | &dev_attr_modalias.attr, |
295 | NULL | |
296 | }; | |
297 | ||
298 | static struct attribute_group i2c_dev_attr_group = { | |
299 | .attrs = i2c_dev_attrs, | |
300 | }; | |
301 | ||
302 | static const struct attribute_group *i2c_dev_attr_groups[] = { | |
303 | &i2c_dev_attr_group, | |
304 | NULL | |
7b4fbc50 DB |
305 | }; |
306 | ||
0b2c3688 | 307 | static const struct dev_pm_ops i2c_device_pm_ops = { |
54067ee2 | 308 | .suspend = i2c_device_pm_suspend, |
309 | .resume = i2c_device_pm_resume, | |
2f60ba70 RW |
310 | .freeze = i2c_device_pm_freeze, |
311 | .thaw = i2c_device_pm_thaw, | |
312 | .poweroff = i2c_device_pm_poweroff, | |
313 | .restore = i2c_device_pm_restore, | |
314 | SET_RUNTIME_PM_OPS( | |
315 | pm_generic_runtime_suspend, | |
316 | pm_generic_runtime_resume, | |
317 | pm_generic_runtime_idle | |
318 | ) | |
54067ee2 | 319 | }; |
320 | ||
e9ca9eb9 | 321 | struct bus_type i2c_bus_type = { |
f37dd80a DB |
322 | .name = "i2c", |
323 | .match = i2c_device_match, | |
324 | .probe = i2c_device_probe, | |
325 | .remove = i2c_device_remove, | |
326 | .shutdown = i2c_device_shutdown, | |
54067ee2 | 327 | .pm = &i2c_device_pm_ops, |
b864c7d5 | 328 | }; |
e9ca9eb9 | 329 | EXPORT_SYMBOL_GPL(i2c_bus_type); |
b864c7d5 | 330 | |
51298d12 JD |
331 | static struct device_type i2c_client_type = { |
332 | .groups = i2c_dev_attr_groups, | |
333 | .uevent = i2c_device_uevent, | |
334 | .release = i2c_client_dev_release, | |
335 | }; | |
336 | ||
9b766b81 DB |
337 | |
338 | /** | |
339 | * i2c_verify_client - return parameter as i2c_client, or NULL | |
340 | * @dev: device, probably from some driver model iterator | |
341 | * | |
342 | * When traversing the driver model tree, perhaps using driver model | |
343 | * iterators like @device_for_each_child(), you can't assume very much | |
344 | * about the nodes you find. Use this function to avoid oopses caused | |
345 | * by wrongly treating some non-I2C device as an i2c_client. | |
346 | */ | |
347 | struct i2c_client *i2c_verify_client(struct device *dev) | |
348 | { | |
51298d12 | 349 | return (dev->type == &i2c_client_type) |
9b766b81 DB |
350 | ? to_i2c_client(dev) |
351 | : NULL; | |
352 | } | |
353 | EXPORT_SYMBOL(i2c_verify_client); | |
354 | ||
355 | ||
3a89db5f | 356 | /* This is a permissive address validity check, I2C address map constraints |
25985edc | 357 | * are purposely not enforced, except for the general call address. */ |
3a89db5f JD |
358 | static int i2c_check_client_addr_validity(const struct i2c_client *client) |
359 | { | |
360 | if (client->flags & I2C_CLIENT_TEN) { | |
361 | /* 10-bit address, all values are valid */ | |
362 | if (client->addr > 0x3ff) | |
363 | return -EINVAL; | |
364 | } else { | |
365 | /* 7-bit address, reject the general call address */ | |
366 | if (client->addr == 0x00 || client->addr > 0x7f) | |
367 | return -EINVAL; | |
368 | } | |
369 | return 0; | |
370 | } | |
371 | ||
656b8761 JD |
372 | /* And this is a strict address validity check, used when probing. If a |
373 | * device uses a reserved address, then it shouldn't be probed. 7-bit | |
374 | * addressing is assumed, 10-bit address devices are rare and should be | |
375 | * explicitly enumerated. */ | |
376 | static int i2c_check_addr_validity(unsigned short addr) | |
377 | { | |
378 | /* | |
379 | * Reserved addresses per I2C specification: | |
380 | * 0x00 General call address / START byte | |
381 | * 0x01 CBUS address | |
382 | * 0x02 Reserved for different bus format | |
383 | * 0x03 Reserved for future purposes | |
384 | * 0x04-0x07 Hs-mode master code | |
385 | * 0x78-0x7b 10-bit slave addressing | |
386 | * 0x7c-0x7f Reserved for future purposes | |
387 | */ | |
388 | if (addr < 0x08 || addr > 0x77) | |
389 | return -EINVAL; | |
390 | return 0; | |
391 | } | |
392 | ||
3b5f794b JD |
393 | static int __i2c_check_addr_busy(struct device *dev, void *addrp) |
394 | { | |
395 | struct i2c_client *client = i2c_verify_client(dev); | |
396 | int addr = *(int *)addrp; | |
397 | ||
398 | if (client && client->addr == addr) | |
399 | return -EBUSY; | |
400 | return 0; | |
401 | } | |
402 | ||
0826374b ML |
403 | /* walk up mux tree */ |
404 | static int i2c_check_mux_parents(struct i2c_adapter *adapter, int addr) | |
405 | { | |
97cc4d49 | 406 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
407 | int result; |
408 | ||
409 | result = device_for_each_child(&adapter->dev, &addr, | |
410 | __i2c_check_addr_busy); | |
411 | ||
97cc4d49 JD |
412 | if (!result && parent) |
413 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
414 | |
415 | return result; | |
416 | } | |
417 | ||
418 | /* recurse down mux tree */ | |
419 | static int i2c_check_mux_children(struct device *dev, void *addrp) | |
420 | { | |
421 | int result; | |
422 | ||
423 | if (dev->type == &i2c_adapter_type) | |
424 | result = device_for_each_child(dev, addrp, | |
425 | i2c_check_mux_children); | |
426 | else | |
427 | result = __i2c_check_addr_busy(dev, addrp); | |
428 | ||
429 | return result; | |
430 | } | |
431 | ||
3b5f794b JD |
432 | static int i2c_check_addr_busy(struct i2c_adapter *adapter, int addr) |
433 | { | |
97cc4d49 | 434 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
0826374b ML |
435 | int result = 0; |
436 | ||
97cc4d49 JD |
437 | if (parent) |
438 | result = i2c_check_mux_parents(parent, addr); | |
0826374b ML |
439 | |
440 | if (!result) | |
441 | result = device_for_each_child(&adapter->dev, &addr, | |
442 | i2c_check_mux_children); | |
443 | ||
444 | return result; | |
3b5f794b JD |
445 | } |
446 | ||
fe61e07e JD |
447 | /** |
448 | * i2c_lock_adapter - Get exclusive access to an I2C bus segment | |
449 | * @adapter: Target I2C bus segment | |
450 | */ | |
451 | void i2c_lock_adapter(struct i2c_adapter *adapter) | |
452 | { | |
97cc4d49 JD |
453 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
454 | ||
455 | if (parent) | |
456 | i2c_lock_adapter(parent); | |
0826374b ML |
457 | else |
458 | rt_mutex_lock(&adapter->bus_lock); | |
fe61e07e JD |
459 | } |
460 | EXPORT_SYMBOL_GPL(i2c_lock_adapter); | |
461 | ||
462 | /** | |
463 | * i2c_trylock_adapter - Try to get exclusive access to an I2C bus segment | |
464 | * @adapter: Target I2C bus segment | |
465 | */ | |
466 | static int i2c_trylock_adapter(struct i2c_adapter *adapter) | |
467 | { | |
97cc4d49 JD |
468 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
469 | ||
470 | if (parent) | |
471 | return i2c_trylock_adapter(parent); | |
0826374b ML |
472 | else |
473 | return rt_mutex_trylock(&adapter->bus_lock); | |
fe61e07e JD |
474 | } |
475 | ||
476 | /** | |
477 | * i2c_unlock_adapter - Release exclusive access to an I2C bus segment | |
478 | * @adapter: Target I2C bus segment | |
479 | */ | |
480 | void i2c_unlock_adapter(struct i2c_adapter *adapter) | |
481 | { | |
97cc4d49 JD |
482 | struct i2c_adapter *parent = i2c_parent_is_i2c_adapter(adapter); |
483 | ||
484 | if (parent) | |
485 | i2c_unlock_adapter(parent); | |
0826374b ML |
486 | else |
487 | rt_mutex_unlock(&adapter->bus_lock); | |
fe61e07e JD |
488 | } |
489 | EXPORT_SYMBOL_GPL(i2c_unlock_adapter); | |
490 | ||
9c1600ed | 491 | /** |
f8a227e8 | 492 | * i2c_new_device - instantiate an i2c device |
9c1600ed DB |
493 | * @adap: the adapter managing the device |
494 | * @info: describes one I2C device; bus_num is ignored | |
d64f73be | 495 | * Context: can sleep |
9c1600ed | 496 | * |
f8a227e8 JD |
497 | * Create an i2c device. Binding is handled through driver model |
498 | * probe()/remove() methods. A driver may be bound to this device when we | |
499 | * return from this function, or any later moment (e.g. maybe hotplugging will | |
500 | * load the driver module). This call is not appropriate for use by mainboard | |
501 | * initialization logic, which usually runs during an arch_initcall() long | |
502 | * before any i2c_adapter could exist. | |
9c1600ed DB |
503 | * |
504 | * This returns the new i2c client, which may be saved for later use with | |
505 | * i2c_unregister_device(); or NULL to indicate an error. | |
506 | */ | |
507 | struct i2c_client * | |
508 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info) | |
509 | { | |
510 | struct i2c_client *client; | |
511 | int status; | |
512 | ||
513 | client = kzalloc(sizeof *client, GFP_KERNEL); | |
514 | if (!client) | |
515 | return NULL; | |
516 | ||
517 | client->adapter = adap; | |
518 | ||
519 | client->dev.platform_data = info->platform_data; | |
3bbb835d | 520 | |
11f1f2af AV |
521 | if (info->archdata) |
522 | client->dev.archdata = *info->archdata; | |
523 | ||
ee35425c | 524 | client->flags = info->flags; |
9c1600ed DB |
525 | client->addr = info->addr; |
526 | client->irq = info->irq; | |
527 | ||
9c1600ed DB |
528 | strlcpy(client->name, info->type, sizeof(client->name)); |
529 | ||
3a89db5f JD |
530 | /* Check for address validity */ |
531 | status = i2c_check_client_addr_validity(client); | |
532 | if (status) { | |
533 | dev_err(&adap->dev, "Invalid %d-bit I2C address 0x%02hx\n", | |
534 | client->flags & I2C_CLIENT_TEN ? 10 : 7, client->addr); | |
535 | goto out_err_silent; | |
536 | } | |
537 | ||
f8a227e8 | 538 | /* Check for address business */ |
3b5f794b | 539 | status = i2c_check_addr_busy(adap, client->addr); |
f8a227e8 JD |
540 | if (status) |
541 | goto out_err; | |
542 | ||
543 | client->dev.parent = &client->adapter->dev; | |
544 | client->dev.bus = &i2c_bus_type; | |
51298d12 | 545 | client->dev.type = &i2c_client_type; |
d12d42f7 | 546 | client->dev.of_node = info->of_node; |
907ddf89 | 547 | ACPI_HANDLE_SET(&client->dev, info->acpi_node.handle); |
f8a227e8 | 548 | |
cbb44514 | 549 | /* For 10-bit clients, add an arbitrary offset to avoid collisions */ |
f8a227e8 | 550 | dev_set_name(&client->dev, "%d-%04x", i2c_adapter_id(adap), |
cbb44514 JD |
551 | client->addr | ((client->flags & I2C_CLIENT_TEN) |
552 | ? 0xa000 : 0)); | |
f8a227e8 JD |
553 | status = device_register(&client->dev); |
554 | if (status) | |
555 | goto out_err; | |
556 | ||
f8a227e8 JD |
557 | dev_dbg(&adap->dev, "client [%s] registered with bus id %s\n", |
558 | client->name, dev_name(&client->dev)); | |
559 | ||
9c1600ed | 560 | return client; |
f8a227e8 JD |
561 | |
562 | out_err: | |
563 | dev_err(&adap->dev, "Failed to register i2c client %s at 0x%02x " | |
564 | "(%d)\n", client->name, client->addr, status); | |
3a89db5f | 565 | out_err_silent: |
f8a227e8 JD |
566 | kfree(client); |
567 | return NULL; | |
9c1600ed DB |
568 | } |
569 | EXPORT_SYMBOL_GPL(i2c_new_device); | |
570 | ||
571 | ||
572 | /** | |
573 | * i2c_unregister_device - reverse effect of i2c_new_device() | |
574 | * @client: value returned from i2c_new_device() | |
d64f73be | 575 | * Context: can sleep |
9c1600ed DB |
576 | */ |
577 | void i2c_unregister_device(struct i2c_client *client) | |
a1d9e6e4 | 578 | { |
a1d9e6e4 DB |
579 | device_unregister(&client->dev); |
580 | } | |
9c1600ed | 581 | EXPORT_SYMBOL_GPL(i2c_unregister_device); |
a1d9e6e4 DB |
582 | |
583 | ||
60b129d7 JD |
584 | static const struct i2c_device_id dummy_id[] = { |
585 | { "dummy", 0 }, | |
586 | { }, | |
587 | }; | |
588 | ||
d2653e92 JD |
589 | static int dummy_probe(struct i2c_client *client, |
590 | const struct i2c_device_id *id) | |
591 | { | |
592 | return 0; | |
593 | } | |
594 | ||
595 | static int dummy_remove(struct i2c_client *client) | |
e9f1373b DB |
596 | { |
597 | return 0; | |
598 | } | |
599 | ||
600 | static struct i2c_driver dummy_driver = { | |
601 | .driver.name = "dummy", | |
d2653e92 JD |
602 | .probe = dummy_probe, |
603 | .remove = dummy_remove, | |
60b129d7 | 604 | .id_table = dummy_id, |
e9f1373b DB |
605 | }; |
606 | ||
607 | /** | |
608 | * i2c_new_dummy - return a new i2c device bound to a dummy driver | |
609 | * @adapter: the adapter managing the device | |
610 | * @address: seven bit address to be used | |
e9f1373b DB |
611 | * Context: can sleep |
612 | * | |
613 | * This returns an I2C client bound to the "dummy" driver, intended for use | |
614 | * with devices that consume multiple addresses. Examples of such chips | |
615 | * include various EEPROMS (like 24c04 and 24c08 models). | |
616 | * | |
617 | * These dummy devices have two main uses. First, most I2C and SMBus calls | |
618 | * except i2c_transfer() need a client handle; the dummy will be that handle. | |
619 | * And second, this prevents the specified address from being bound to a | |
620 | * different driver. | |
621 | * | |
622 | * This returns the new i2c client, which should be saved for later use with | |
623 | * i2c_unregister_device(); or NULL to indicate an error. | |
624 | */ | |
09b8ce0a | 625 | struct i2c_client *i2c_new_dummy(struct i2c_adapter *adapter, u16 address) |
e9f1373b DB |
626 | { |
627 | struct i2c_board_info info = { | |
60b129d7 | 628 | I2C_BOARD_INFO("dummy", address), |
e9f1373b DB |
629 | }; |
630 | ||
e9f1373b DB |
631 | return i2c_new_device(adapter, &info); |
632 | } | |
633 | EXPORT_SYMBOL_GPL(i2c_new_dummy); | |
634 | ||
f37dd80a DB |
635 | /* ------------------------------------------------------------------------- */ |
636 | ||
16ffadfc DB |
637 | /* I2C bus adapters -- one roots each I2C or SMBUS segment */ |
638 | ||
83eaaed0 | 639 | static void i2c_adapter_dev_release(struct device *dev) |
1da177e4 | 640 | { |
ef2c8321 | 641 | struct i2c_adapter *adap = to_i2c_adapter(dev); |
1da177e4 LT |
642 | complete(&adap->dev_released); |
643 | } | |
644 | ||
390946b1 JD |
645 | /* |
646 | * This function is only needed for mutex_lock_nested, so it is never | |
647 | * called unless locking correctness checking is enabled. Thus we | |
648 | * make it inline to avoid a compiler warning. That's what gcc ends up | |
649 | * doing anyway. | |
650 | */ | |
651 | static inline unsigned int i2c_adapter_depth(struct i2c_adapter *adapter) | |
652 | { | |
653 | unsigned int depth = 0; | |
654 | ||
655 | while ((adapter = i2c_parent_is_i2c_adapter(adapter))) | |
656 | depth++; | |
657 | ||
658 | return depth; | |
659 | } | |
660 | ||
99cd8e25 JD |
661 | /* |
662 | * Let users instantiate I2C devices through sysfs. This can be used when | |
663 | * platform initialization code doesn't contain the proper data for | |
664 | * whatever reason. Also useful for drivers that do device detection and | |
665 | * detection fails, either because the device uses an unexpected address, | |
666 | * or this is a compatible device with different ID register values. | |
667 | * | |
668 | * Parameter checking may look overzealous, but we really don't want | |
669 | * the user to provide incorrect parameters. | |
670 | */ | |
671 | static ssize_t | |
672 | i2c_sysfs_new_device(struct device *dev, struct device_attribute *attr, | |
673 | const char *buf, size_t count) | |
674 | { | |
675 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
676 | struct i2c_board_info info; | |
677 | struct i2c_client *client; | |
678 | char *blank, end; | |
679 | int res; | |
680 | ||
99cd8e25 JD |
681 | memset(&info, 0, sizeof(struct i2c_board_info)); |
682 | ||
683 | blank = strchr(buf, ' '); | |
684 | if (!blank) { | |
685 | dev_err(dev, "%s: Missing parameters\n", "new_device"); | |
686 | return -EINVAL; | |
687 | } | |
688 | if (blank - buf > I2C_NAME_SIZE - 1) { | |
689 | dev_err(dev, "%s: Invalid device name\n", "new_device"); | |
690 | return -EINVAL; | |
691 | } | |
692 | memcpy(info.type, buf, blank - buf); | |
693 | ||
694 | /* Parse remaining parameters, reject extra parameters */ | |
695 | res = sscanf(++blank, "%hi%c", &info.addr, &end); | |
696 | if (res < 1) { | |
697 | dev_err(dev, "%s: Can't parse I2C address\n", "new_device"); | |
698 | return -EINVAL; | |
699 | } | |
700 | if (res > 1 && end != '\n') { | |
701 | dev_err(dev, "%s: Extra parameters\n", "new_device"); | |
702 | return -EINVAL; | |
703 | } | |
704 | ||
99cd8e25 JD |
705 | client = i2c_new_device(adap, &info); |
706 | if (!client) | |
3a89db5f | 707 | return -EINVAL; |
99cd8e25 JD |
708 | |
709 | /* Keep track of the added device */ | |
dafc50d1 | 710 | mutex_lock(&adap->userspace_clients_lock); |
6629dcff | 711 | list_add_tail(&client->detected, &adap->userspace_clients); |
dafc50d1 | 712 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
713 | dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", |
714 | info.type, info.addr); | |
715 | ||
716 | return count; | |
717 | } | |
718 | ||
719 | /* | |
720 | * And of course let the users delete the devices they instantiated, if | |
721 | * they got it wrong. This interface can only be used to delete devices | |
722 | * instantiated by i2c_sysfs_new_device above. This guarantees that we | |
723 | * don't delete devices to which some kernel code still has references. | |
724 | * | |
725 | * Parameter checking may look overzealous, but we really don't want | |
726 | * the user to delete the wrong device. | |
727 | */ | |
728 | static ssize_t | |
729 | i2c_sysfs_delete_device(struct device *dev, struct device_attribute *attr, | |
730 | const char *buf, size_t count) | |
731 | { | |
732 | struct i2c_adapter *adap = to_i2c_adapter(dev); | |
733 | struct i2c_client *client, *next; | |
734 | unsigned short addr; | |
735 | char end; | |
736 | int res; | |
737 | ||
738 | /* Parse parameters, reject extra parameters */ | |
739 | res = sscanf(buf, "%hi%c", &addr, &end); | |
740 | if (res < 1) { | |
741 | dev_err(dev, "%s: Can't parse I2C address\n", "delete_device"); | |
742 | return -EINVAL; | |
743 | } | |
744 | if (res > 1 && end != '\n') { | |
745 | dev_err(dev, "%s: Extra parameters\n", "delete_device"); | |
746 | return -EINVAL; | |
747 | } | |
748 | ||
749 | /* Make sure the device was added through sysfs */ | |
750 | res = -ENOENT; | |
390946b1 JD |
751 | mutex_lock_nested(&adap->userspace_clients_lock, |
752 | i2c_adapter_depth(adap)); | |
6629dcff JD |
753 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
754 | detected) { | |
755 | if (client->addr == addr) { | |
99cd8e25 JD |
756 | dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", |
757 | "delete_device", client->name, client->addr); | |
758 | ||
759 | list_del(&client->detected); | |
760 | i2c_unregister_device(client); | |
761 | res = count; | |
762 | break; | |
763 | } | |
764 | } | |
dafc50d1 | 765 | mutex_unlock(&adap->userspace_clients_lock); |
99cd8e25 JD |
766 | |
767 | if (res < 0) | |
768 | dev_err(dev, "%s: Can't find device in list\n", | |
769 | "delete_device"); | |
770 | return res; | |
771 | } | |
772 | ||
4f8cf824 JD |
773 | static DEVICE_ATTR(new_device, S_IWUSR, NULL, i2c_sysfs_new_device); |
774 | static DEVICE_ATTR(delete_device, S_IWUSR, NULL, i2c_sysfs_delete_device); | |
775 | ||
776 | static struct attribute *i2c_adapter_attrs[] = { | |
777 | &dev_attr_name.attr, | |
778 | &dev_attr_new_device.attr, | |
779 | &dev_attr_delete_device.attr, | |
780 | NULL | |
781 | }; | |
782 | ||
783 | static struct attribute_group i2c_adapter_attr_group = { | |
784 | .attrs = i2c_adapter_attrs, | |
785 | }; | |
786 | ||
787 | static const struct attribute_group *i2c_adapter_attr_groups[] = { | |
788 | &i2c_adapter_attr_group, | |
789 | NULL | |
16ffadfc | 790 | }; |
b119dc3f | 791 | |
0826374b | 792 | struct device_type i2c_adapter_type = { |
4f8cf824 JD |
793 | .groups = i2c_adapter_attr_groups, |
794 | .release = i2c_adapter_dev_release, | |
1da177e4 | 795 | }; |
0826374b | 796 | EXPORT_SYMBOL_GPL(i2c_adapter_type); |
1da177e4 | 797 | |
643dd09e SW |
798 | /** |
799 | * i2c_verify_adapter - return parameter as i2c_adapter or NULL | |
800 | * @dev: device, probably from some driver model iterator | |
801 | * | |
802 | * When traversing the driver model tree, perhaps using driver model | |
803 | * iterators like @device_for_each_child(), you can't assume very much | |
804 | * about the nodes you find. Use this function to avoid oopses caused | |
805 | * by wrongly treating some non-I2C device as an i2c_adapter. | |
806 | */ | |
807 | struct i2c_adapter *i2c_verify_adapter(struct device *dev) | |
808 | { | |
809 | return (dev->type == &i2c_adapter_type) | |
810 | ? to_i2c_adapter(dev) | |
811 | : NULL; | |
812 | } | |
813 | EXPORT_SYMBOL(i2c_verify_adapter); | |
814 | ||
2bb5095a JD |
815 | #ifdef CONFIG_I2C_COMPAT |
816 | static struct class_compat *i2c_adapter_compat_class; | |
817 | #endif | |
818 | ||
9c1600ed DB |
819 | static void i2c_scan_static_board_info(struct i2c_adapter *adapter) |
820 | { | |
821 | struct i2c_devinfo *devinfo; | |
822 | ||
f18c41da | 823 | down_read(&__i2c_board_lock); |
9c1600ed DB |
824 | list_for_each_entry(devinfo, &__i2c_board_list, list) { |
825 | if (devinfo->busnum == adapter->nr | |
826 | && !i2c_new_device(adapter, | |
827 | &devinfo->board_info)) | |
09b8ce0a ZX |
828 | dev_err(&adapter->dev, |
829 | "Can't create device at 0x%02x\n", | |
9c1600ed DB |
830 | devinfo->board_info.addr); |
831 | } | |
f18c41da | 832 | up_read(&__i2c_board_lock); |
9c1600ed DB |
833 | } |
834 | ||
69b0089a JD |
835 | static int i2c_do_add_adapter(struct i2c_driver *driver, |
836 | struct i2c_adapter *adap) | |
026526f5 | 837 | { |
4735c98f JD |
838 | /* Detect supported devices on that bus, and instantiate them */ |
839 | i2c_detect(adap, driver); | |
840 | ||
841 | /* Let legacy drivers scan this bus for matching devices */ | |
026526f5 | 842 | if (driver->attach_adapter) { |
a920ff41 JD |
843 | dev_warn(&adap->dev, "%s: attach_adapter method is deprecated\n", |
844 | driver->driver.name); | |
fe6fc258 JD |
845 | dev_warn(&adap->dev, "Please use another way to instantiate " |
846 | "your i2c_client\n"); | |
026526f5 JD |
847 | /* We ignore the return code; if it fails, too bad */ |
848 | driver->attach_adapter(adap); | |
849 | } | |
850 | return 0; | |
851 | } | |
852 | ||
69b0089a JD |
853 | static int __process_new_adapter(struct device_driver *d, void *data) |
854 | { | |
855 | return i2c_do_add_adapter(to_i2c_driver(d), data); | |
856 | } | |
857 | ||
6e13e641 | 858 | static int i2c_register_adapter(struct i2c_adapter *adap) |
1da177e4 | 859 | { |
d6703281 | 860 | int res = 0; |
1da177e4 | 861 | |
1d0b19c9 | 862 | /* Can't register until after driver model init */ |
35fc37f8 JD |
863 | if (unlikely(WARN_ON(!i2c_bus_type.p))) { |
864 | res = -EAGAIN; | |
865 | goto out_list; | |
866 | } | |
1d0b19c9 | 867 | |
2236baa7 JD |
868 | /* Sanity checks */ |
869 | if (unlikely(adap->name[0] == '\0')) { | |
870 | pr_err("i2c-core: Attempt to register an adapter with " | |
871 | "no name!\n"); | |
872 | return -EINVAL; | |
873 | } | |
874 | if (unlikely(!adap->algo)) { | |
875 | pr_err("i2c-core: Attempt to register adapter '%s' with " | |
876 | "no algo!\n", adap->name); | |
877 | return -EINVAL; | |
878 | } | |
879 | ||
194684e5 | 880 | rt_mutex_init(&adap->bus_lock); |
dafc50d1 | 881 | mutex_init(&adap->userspace_clients_lock); |
6629dcff | 882 | INIT_LIST_HEAD(&adap->userspace_clients); |
1da177e4 | 883 | |
8fcfef6e JD |
884 | /* Set default timeout to 1 second if not already set */ |
885 | if (adap->timeout == 0) | |
886 | adap->timeout = HZ; | |
887 | ||
27d9c183 | 888 | dev_set_name(&adap->dev, "i2c-%d", adap->nr); |
4f8cf824 JD |
889 | adap->dev.bus = &i2c_bus_type; |
890 | adap->dev.type = &i2c_adapter_type; | |
b119c6c9 JD |
891 | res = device_register(&adap->dev); |
892 | if (res) | |
893 | goto out_list; | |
1da177e4 | 894 | |
b6d7b3d1 JD |
895 | dev_dbg(&adap->dev, "adapter [%s] registered\n", adap->name); |
896 | ||
2bb5095a JD |
897 | #ifdef CONFIG_I2C_COMPAT |
898 | res = class_compat_create_link(i2c_adapter_compat_class, &adap->dev, | |
899 | adap->dev.parent); | |
900 | if (res) | |
901 | dev_warn(&adap->dev, | |
902 | "Failed to create compatibility class link\n"); | |
903 | #endif | |
904 | ||
729d6dd5 | 905 | /* create pre-declared device nodes */ |
6e13e641 DB |
906 | if (adap->nr < __i2c_first_dynamic_bus_num) |
907 | i2c_scan_static_board_info(adap); | |
908 | ||
4735c98f | 909 | /* Notify drivers */ |
35fc37f8 | 910 | mutex_lock(&core_lock); |
d6703281 | 911 | bus_for_each_drv(&i2c_bus_type, NULL, adap, __process_new_adapter); |
caada32a | 912 | mutex_unlock(&core_lock); |
35fc37f8 JD |
913 | |
914 | return 0; | |
b119c6c9 | 915 | |
b119c6c9 | 916 | out_list: |
35fc37f8 | 917 | mutex_lock(&core_lock); |
b119c6c9 | 918 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 JD |
919 | mutex_unlock(&core_lock); |
920 | return res; | |
1da177e4 LT |
921 | } |
922 | ||
ee5c2744 DA |
923 | /** |
924 | * __i2c_add_numbered_adapter - i2c_add_numbered_adapter where nr is never -1 | |
925 | * @adap: the adapter to register (with adap->nr initialized) | |
926 | * Context: can sleep | |
927 | * | |
928 | * See i2c_add_numbered_adapter() for details. | |
929 | */ | |
930 | static int __i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
931 | { | |
932 | int id; | |
933 | ||
934 | mutex_lock(&core_lock); | |
935 | id = idr_alloc(&i2c_adapter_idr, adap, adap->nr, adap->nr + 1, | |
936 | GFP_KERNEL); | |
937 | mutex_unlock(&core_lock); | |
938 | if (id < 0) | |
939 | return id == -ENOSPC ? -EBUSY : id; | |
940 | ||
941 | return i2c_register_adapter(adap); | |
942 | } | |
943 | ||
6e13e641 DB |
944 | /** |
945 | * i2c_add_adapter - declare i2c adapter, use dynamic bus number | |
946 | * @adapter: the adapter to add | |
d64f73be | 947 | * Context: can sleep |
6e13e641 DB |
948 | * |
949 | * This routine is used to declare an I2C adapter when its bus number | |
ee5c2744 DA |
950 | * doesn't matter or when its bus number is specified by an dt alias. |
951 | * Examples of bases when the bus number doesn't matter: I2C adapters | |
952 | * dynamically added by USB links or PCI plugin cards. | |
6e13e641 DB |
953 | * |
954 | * When this returns zero, a new bus number was allocated and stored | |
955 | * in adap->nr, and the specified adapter became available for clients. | |
956 | * Otherwise, a negative errno value is returned. | |
957 | */ | |
958 | int i2c_add_adapter(struct i2c_adapter *adapter) | |
959 | { | |
ee5c2744 | 960 | struct device *dev = &adapter->dev; |
4ae42b0f | 961 | int id; |
6e13e641 | 962 | |
ee5c2744 DA |
963 | if (dev->of_node) { |
964 | id = of_alias_get_id(dev->of_node, "i2c"); | |
965 | if (id >= 0) { | |
966 | adapter->nr = id; | |
967 | return __i2c_add_numbered_adapter(adapter); | |
968 | } | |
969 | } | |
970 | ||
caada32a | 971 | mutex_lock(&core_lock); |
4ae42b0f TH |
972 | id = idr_alloc(&i2c_adapter_idr, adapter, |
973 | __i2c_first_dynamic_bus_num, 0, GFP_KERNEL); | |
caada32a | 974 | mutex_unlock(&core_lock); |
4ae42b0f TH |
975 | if (id < 0) |
976 | return id; | |
6e13e641 DB |
977 | |
978 | adapter->nr = id; | |
4ae42b0f | 979 | |
6e13e641 DB |
980 | return i2c_register_adapter(adapter); |
981 | } | |
982 | EXPORT_SYMBOL(i2c_add_adapter); | |
983 | ||
984 | /** | |
985 | * i2c_add_numbered_adapter - declare i2c adapter, use static bus number | |
986 | * @adap: the adapter to register (with adap->nr initialized) | |
d64f73be | 987 | * Context: can sleep |
6e13e641 DB |
988 | * |
989 | * This routine is used to declare an I2C adapter when its bus number | |
8c07e46f RD |
990 | * matters. For example, use it for I2C adapters from system-on-chip CPUs, |
991 | * or otherwise built in to the system's mainboard, and where i2c_board_info | |
6e13e641 DB |
992 | * is used to properly configure I2C devices. |
993 | * | |
488bf314 GL |
994 | * If the requested bus number is set to -1, then this function will behave |
995 | * identically to i2c_add_adapter, and will dynamically assign a bus number. | |
996 | * | |
6e13e641 DB |
997 | * If no devices have pre-been declared for this bus, then be sure to |
998 | * register the adapter before any dynamically allocated ones. Otherwise | |
999 | * the required bus ID may not be available. | |
1000 | * | |
1001 | * When this returns zero, the specified adapter became available for | |
1002 | * clients using the bus number provided in adap->nr. Also, the table | |
1003 | * of I2C devices pre-declared using i2c_register_board_info() is scanned, | |
1004 | * and the appropriate driver model device nodes are created. Otherwise, a | |
1005 | * negative errno value is returned. | |
1006 | */ | |
1007 | int i2c_add_numbered_adapter(struct i2c_adapter *adap) | |
1008 | { | |
488bf314 GL |
1009 | if (adap->nr == -1) /* -1 means dynamically assign bus id */ |
1010 | return i2c_add_adapter(adap); | |
6e13e641 | 1011 | |
ee5c2744 | 1012 | return __i2c_add_numbered_adapter(adap); |
6e13e641 DB |
1013 | } |
1014 | EXPORT_SYMBOL_GPL(i2c_add_numbered_adapter); | |
1015 | ||
69b0089a JD |
1016 | static int i2c_do_del_adapter(struct i2c_driver *driver, |
1017 | struct i2c_adapter *adapter) | |
026526f5 | 1018 | { |
4735c98f | 1019 | struct i2c_client *client, *_n; |
026526f5 JD |
1020 | int res; |
1021 | ||
acec211c JD |
1022 | /* Remove the devices we created ourselves as the result of hardware |
1023 | * probing (using a driver's detect method) */ | |
4735c98f JD |
1024 | list_for_each_entry_safe(client, _n, &driver->clients, detected) { |
1025 | if (client->adapter == adapter) { | |
1026 | dev_dbg(&adapter->dev, "Removing %s at 0x%x\n", | |
1027 | client->name, client->addr); | |
1028 | list_del(&client->detected); | |
1029 | i2c_unregister_device(client); | |
1030 | } | |
1031 | } | |
1032 | ||
026526f5 JD |
1033 | if (!driver->detach_adapter) |
1034 | return 0; | |
a920ff41 JD |
1035 | dev_warn(&adapter->dev, "%s: detach_adapter method is deprecated\n", |
1036 | driver->driver.name); | |
026526f5 JD |
1037 | res = driver->detach_adapter(adapter); |
1038 | if (res) | |
1039 | dev_err(&adapter->dev, "detach_adapter failed (%d) " | |
1040 | "for driver [%s]\n", res, driver->driver.name); | |
1041 | return res; | |
1042 | } | |
1043 | ||
e549c2b5 | 1044 | static int __unregister_client(struct device *dev, void *dummy) |
5219bf88 JD |
1045 | { |
1046 | struct i2c_client *client = i2c_verify_client(dev); | |
1047 | if (client && strcmp(client->name, "dummy")) | |
1048 | i2c_unregister_device(client); | |
1049 | return 0; | |
1050 | } | |
1051 | ||
1052 | static int __unregister_dummy(struct device *dev, void *dummy) | |
e549c2b5 JD |
1053 | { |
1054 | struct i2c_client *client = i2c_verify_client(dev); | |
1055 | if (client) | |
1056 | i2c_unregister_device(client); | |
1057 | return 0; | |
1058 | } | |
1059 | ||
69b0089a JD |
1060 | static int __process_removed_adapter(struct device_driver *d, void *data) |
1061 | { | |
1062 | return i2c_do_del_adapter(to_i2c_driver(d), data); | |
1063 | } | |
1064 | ||
d64f73be DB |
1065 | /** |
1066 | * i2c_del_adapter - unregister I2C adapter | |
1067 | * @adap: the adapter being unregistered | |
1068 | * Context: can sleep | |
1069 | * | |
1070 | * This unregisters an I2C adapter which was previously registered | |
1071 | * by @i2c_add_adapter or @i2c_add_numbered_adapter. | |
1072 | */ | |
1da177e4 LT |
1073 | int i2c_del_adapter(struct i2c_adapter *adap) |
1074 | { | |
1da177e4 | 1075 | int res = 0; |
35fc37f8 | 1076 | struct i2c_adapter *found; |
bbd2d9c9 | 1077 | struct i2c_client *client, *next; |
1da177e4 LT |
1078 | |
1079 | /* First make sure that this adapter was ever added */ | |
35fc37f8 JD |
1080 | mutex_lock(&core_lock); |
1081 | found = idr_find(&i2c_adapter_idr, adap->nr); | |
1082 | mutex_unlock(&core_lock); | |
1083 | if (found != adap) { | |
b6d7b3d1 JD |
1084 | pr_debug("i2c-core: attempting to delete unregistered " |
1085 | "adapter [%s]\n", adap->name); | |
35fc37f8 | 1086 | return -EINVAL; |
1da177e4 LT |
1087 | } |
1088 | ||
026526f5 | 1089 | /* Tell drivers about this removal */ |
35fc37f8 | 1090 | mutex_lock(&core_lock); |
026526f5 | 1091 | res = bus_for_each_drv(&i2c_bus_type, NULL, adap, |
69b0089a | 1092 | __process_removed_adapter); |
35fc37f8 | 1093 | mutex_unlock(&core_lock); |
026526f5 | 1094 | if (res) |
35fc37f8 | 1095 | return res; |
1da177e4 | 1096 | |
bbd2d9c9 | 1097 | /* Remove devices instantiated from sysfs */ |
390946b1 JD |
1098 | mutex_lock_nested(&adap->userspace_clients_lock, |
1099 | i2c_adapter_depth(adap)); | |
6629dcff JD |
1100 | list_for_each_entry_safe(client, next, &adap->userspace_clients, |
1101 | detected) { | |
1102 | dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, | |
1103 | client->addr); | |
1104 | list_del(&client->detected); | |
1105 | i2c_unregister_device(client); | |
bbd2d9c9 | 1106 | } |
dafc50d1 | 1107 | mutex_unlock(&adap->userspace_clients_lock); |
bbd2d9c9 | 1108 | |
e549c2b5 | 1109 | /* Detach any active clients. This can't fail, thus we do not |
5219bf88 JD |
1110 | * check the returned value. This is a two-pass process, because |
1111 | * we can't remove the dummy devices during the first pass: they | |
1112 | * could have been instantiated by real devices wishing to clean | |
1113 | * them up properly, so we give them a chance to do that first. */ | |
e549c2b5 | 1114 | res = device_for_each_child(&adap->dev, NULL, __unregister_client); |
5219bf88 | 1115 | res = device_for_each_child(&adap->dev, NULL, __unregister_dummy); |
1da177e4 | 1116 | |
2bb5095a JD |
1117 | #ifdef CONFIG_I2C_COMPAT |
1118 | class_compat_remove_link(i2c_adapter_compat_class, &adap->dev, | |
1119 | adap->dev.parent); | |
1120 | #endif | |
1121 | ||
c5567521 TLSC |
1122 | /* device name is gone after device_unregister */ |
1123 | dev_dbg(&adap->dev, "adapter [%s] unregistered\n", adap->name); | |
1124 | ||
1da177e4 LT |
1125 | /* clean up the sysfs representation */ |
1126 | init_completion(&adap->dev_released); | |
1da177e4 | 1127 | device_unregister(&adap->dev); |
1da177e4 LT |
1128 | |
1129 | /* wait for sysfs to drop all references */ | |
1130 | wait_for_completion(&adap->dev_released); | |
1da177e4 | 1131 | |
6e13e641 | 1132 | /* free bus id */ |
35fc37f8 | 1133 | mutex_lock(&core_lock); |
1da177e4 | 1134 | idr_remove(&i2c_adapter_idr, adap->nr); |
35fc37f8 | 1135 | mutex_unlock(&core_lock); |
1da177e4 | 1136 | |
bd4bc3db JD |
1137 | /* Clear the device structure in case this adapter is ever going to be |
1138 | added again */ | |
1139 | memset(&adap->dev, 0, sizeof(adap->dev)); | |
1140 | ||
35fc37f8 | 1141 | return 0; |
1da177e4 | 1142 | } |
c0564606 | 1143 | EXPORT_SYMBOL(i2c_del_adapter); |
1da177e4 LT |
1144 | |
1145 | ||
7b4fbc50 DB |
1146 | /* ------------------------------------------------------------------------- */ |
1147 | ||
7ae31482 JD |
1148 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)) |
1149 | { | |
1150 | int res; | |
1151 | ||
1152 | mutex_lock(&core_lock); | |
1153 | res = bus_for_each_dev(&i2c_bus_type, NULL, data, fn); | |
1154 | mutex_unlock(&core_lock); | |
1155 | ||
1156 | return res; | |
1157 | } | |
1158 | EXPORT_SYMBOL_GPL(i2c_for_each_dev); | |
1159 | ||
69b0089a | 1160 | static int __process_new_driver(struct device *dev, void *data) |
7f101a97 | 1161 | { |
4f8cf824 JD |
1162 | if (dev->type != &i2c_adapter_type) |
1163 | return 0; | |
69b0089a | 1164 | return i2c_do_add_adapter(data, to_i2c_adapter(dev)); |
7f101a97 DY |
1165 | } |
1166 | ||
7b4fbc50 DB |
1167 | /* |
1168 | * An i2c_driver is used with one or more i2c_client (device) nodes to access | |
729d6dd5 | 1169 | * i2c slave chips, on a bus instance associated with some i2c_adapter. |
1da177e4 LT |
1170 | */ |
1171 | ||
de59cf9e | 1172 | int i2c_register_driver(struct module *owner, struct i2c_driver *driver) |
1da177e4 | 1173 | { |
7eebcb7c | 1174 | int res; |
1da177e4 | 1175 | |
1d0b19c9 DB |
1176 | /* Can't register until after driver model init */ |
1177 | if (unlikely(WARN_ON(!i2c_bus_type.p))) | |
1178 | return -EAGAIN; | |
1179 | ||
1da177e4 | 1180 | /* add the driver to the list of i2c drivers in the driver core */ |
de59cf9e | 1181 | driver->driver.owner = owner; |
1da177e4 | 1182 | driver->driver.bus = &i2c_bus_type; |
1da177e4 | 1183 | |
729d6dd5 | 1184 | /* When registration returns, the driver core |
6e13e641 DB |
1185 | * will have called probe() for all matching-but-unbound devices. |
1186 | */ | |
1da177e4 LT |
1187 | res = driver_register(&driver->driver); |
1188 | if (res) | |
7eebcb7c | 1189 | return res; |
438d6c2c | 1190 | |
f4e8db31 MB |
1191 | /* Drivers should switch to dev_pm_ops instead. */ |
1192 | if (driver->suspend) | |
1193 | pr_warn("i2c-core: driver [%s] using legacy suspend method\n", | |
1194 | driver->driver.name); | |
1195 | if (driver->resume) | |
1196 | pr_warn("i2c-core: driver [%s] using legacy resume method\n", | |
1197 | driver->driver.name); | |
1198 | ||
35d8b2e6 | 1199 | pr_debug("i2c-core: driver [%s] registered\n", driver->driver.name); |
1da177e4 | 1200 | |
4735c98f JD |
1201 | INIT_LIST_HEAD(&driver->clients); |
1202 | /* Walk the adapters that are already present */ | |
7ae31482 | 1203 | i2c_for_each_dev(driver, __process_new_driver); |
35fc37f8 | 1204 | |
7f101a97 DY |
1205 | return 0; |
1206 | } | |
1207 | EXPORT_SYMBOL(i2c_register_driver); | |
1208 | ||
69b0089a | 1209 | static int __process_removed_driver(struct device *dev, void *data) |
7f101a97 | 1210 | { |
4f8cf824 JD |
1211 | if (dev->type != &i2c_adapter_type) |
1212 | return 0; | |
69b0089a | 1213 | return i2c_do_del_adapter(data, to_i2c_adapter(dev)); |
1da177e4 LT |
1214 | } |
1215 | ||
a1d9e6e4 DB |
1216 | /** |
1217 | * i2c_del_driver - unregister I2C driver | |
1218 | * @driver: the driver being unregistered | |
d64f73be | 1219 | * Context: can sleep |
a1d9e6e4 | 1220 | */ |
b3e82096 | 1221 | void i2c_del_driver(struct i2c_driver *driver) |
1da177e4 | 1222 | { |
7ae31482 | 1223 | i2c_for_each_dev(driver, __process_removed_driver); |
1da177e4 LT |
1224 | |
1225 | driver_unregister(&driver->driver); | |
35d8b2e6 | 1226 | pr_debug("i2c-core: driver [%s] unregistered\n", driver->driver.name); |
1da177e4 | 1227 | } |
c0564606 | 1228 | EXPORT_SYMBOL(i2c_del_driver); |
1da177e4 | 1229 | |
7b4fbc50 DB |
1230 | /* ------------------------------------------------------------------------- */ |
1231 | ||
e48d3319 JD |
1232 | /** |
1233 | * i2c_use_client - increments the reference count of the i2c client structure | |
1234 | * @client: the client being referenced | |
1235 | * | |
1236 | * Each live reference to a client should be refcounted. The driver model does | |
1237 | * that automatically as part of driver binding, so that most drivers don't | |
1238 | * need to do this explicitly: they hold a reference until they're unbound | |
1239 | * from the device. | |
1240 | * | |
1241 | * A pointer to the client with the incremented reference counter is returned. | |
1242 | */ | |
1243 | struct i2c_client *i2c_use_client(struct i2c_client *client) | |
1da177e4 | 1244 | { |
6ea438ec DB |
1245 | if (client && get_device(&client->dev)) |
1246 | return client; | |
1247 | return NULL; | |
1da177e4 | 1248 | } |
c0564606 | 1249 | EXPORT_SYMBOL(i2c_use_client); |
1da177e4 | 1250 | |
e48d3319 JD |
1251 | /** |
1252 | * i2c_release_client - release a use of the i2c client structure | |
1253 | * @client: the client being no longer referenced | |
1254 | * | |
1255 | * Must be called when a user of a client is finished with it. | |
1256 | */ | |
1257 | void i2c_release_client(struct i2c_client *client) | |
1da177e4 | 1258 | { |
6ea438ec DB |
1259 | if (client) |
1260 | put_device(&client->dev); | |
1da177e4 | 1261 | } |
c0564606 | 1262 | EXPORT_SYMBOL(i2c_release_client); |
1da177e4 | 1263 | |
9b766b81 DB |
1264 | struct i2c_cmd_arg { |
1265 | unsigned cmd; | |
1266 | void *arg; | |
1267 | }; | |
1268 | ||
1269 | static int i2c_cmd(struct device *dev, void *_arg) | |
1270 | { | |
1271 | struct i2c_client *client = i2c_verify_client(dev); | |
1272 | struct i2c_cmd_arg *arg = _arg; | |
1273 | ||
1274 | if (client && client->driver && client->driver->command) | |
1275 | client->driver->command(client, arg->cmd, arg->arg); | |
1276 | return 0; | |
1277 | } | |
1278 | ||
1da177e4 LT |
1279 | void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg) |
1280 | { | |
9b766b81 | 1281 | struct i2c_cmd_arg cmd_arg; |
1da177e4 | 1282 | |
9b766b81 DB |
1283 | cmd_arg.cmd = cmd; |
1284 | cmd_arg.arg = arg; | |
1285 | device_for_each_child(&adap->dev, &cmd_arg, i2c_cmd); | |
1da177e4 | 1286 | } |
c0564606 | 1287 | EXPORT_SYMBOL(i2c_clients_command); |
1da177e4 LT |
1288 | |
1289 | static int __init i2c_init(void) | |
1290 | { | |
1291 | int retval; | |
1292 | ||
1293 | retval = bus_register(&i2c_bus_type); | |
1da177e4 LT |
1294 | if (retval) |
1295 | return retval; | |
2bb5095a JD |
1296 | #ifdef CONFIG_I2C_COMPAT |
1297 | i2c_adapter_compat_class = class_compat_register("i2c-adapter"); | |
1298 | if (!i2c_adapter_compat_class) { | |
1299 | retval = -ENOMEM; | |
1300 | goto bus_err; | |
1301 | } | |
1302 | #endif | |
e9f1373b DB |
1303 | retval = i2c_add_driver(&dummy_driver); |
1304 | if (retval) | |
2bb5095a | 1305 | goto class_err; |
e9f1373b DB |
1306 | return 0; |
1307 | ||
2bb5095a JD |
1308 | class_err: |
1309 | #ifdef CONFIG_I2C_COMPAT | |
1310 | class_compat_unregister(i2c_adapter_compat_class); | |
e9f1373b | 1311 | bus_err: |
2bb5095a | 1312 | #endif |
e9f1373b DB |
1313 | bus_unregister(&i2c_bus_type); |
1314 | return retval; | |
1da177e4 LT |
1315 | } |
1316 | ||
1317 | static void __exit i2c_exit(void) | |
1318 | { | |
e9f1373b | 1319 | i2c_del_driver(&dummy_driver); |
2bb5095a JD |
1320 | #ifdef CONFIG_I2C_COMPAT |
1321 | class_compat_unregister(i2c_adapter_compat_class); | |
1322 | #endif | |
1da177e4 LT |
1323 | bus_unregister(&i2c_bus_type); |
1324 | } | |
1325 | ||
a10f9e7c DB |
1326 | /* We must initialize early, because some subsystems register i2c drivers |
1327 | * in subsys_initcall() code, but are linked (and initialized) before i2c. | |
1328 | */ | |
1329 | postcore_initcall(i2c_init); | |
1da177e4 LT |
1330 | module_exit(i2c_exit); |
1331 | ||
1332 | /* ---------------------------------------------------- | |
1333 | * the functional interface to the i2c busses. | |
1334 | * ---------------------------------------------------- | |
1335 | */ | |
1336 | ||
b37d2a3a JD |
1337 | /** |
1338 | * __i2c_transfer - unlocked flavor of i2c_transfer | |
1339 | * @adap: Handle to I2C bus | |
1340 | * @msgs: One or more messages to execute before STOP is issued to | |
1341 | * terminate the operation; each message begins with a START. | |
1342 | * @num: Number of messages to be executed. | |
1343 | * | |
1344 | * Returns negative errno, else the number of messages executed. | |
1345 | * | |
1346 | * Adapter lock must be held when calling this function. No debug logging | |
1347 | * takes place. adap->algo->master_xfer existence isn't checked. | |
1348 | */ | |
1349 | int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) | |
1350 | { | |
1351 | unsigned long orig_jiffies; | |
1352 | int ret, try; | |
1353 | ||
1354 | /* Retry automatically on arbitration loss */ | |
1355 | orig_jiffies = jiffies; | |
1356 | for (ret = 0, try = 0; try <= adap->retries; try++) { | |
1357 | ret = adap->algo->master_xfer(adap, msgs, num); | |
1358 | if (ret != -EAGAIN) | |
1359 | break; | |
1360 | if (time_after(jiffies, orig_jiffies + adap->timeout)) | |
1361 | break; | |
1362 | } | |
1363 | ||
1364 | return ret; | |
1365 | } | |
1366 | EXPORT_SYMBOL(__i2c_transfer); | |
1367 | ||
a1cdedac DB |
1368 | /** |
1369 | * i2c_transfer - execute a single or combined I2C message | |
1370 | * @adap: Handle to I2C bus | |
1371 | * @msgs: One or more messages to execute before STOP is issued to | |
1372 | * terminate the operation; each message begins with a START. | |
1373 | * @num: Number of messages to be executed. | |
1374 | * | |
1375 | * Returns negative errno, else the number of messages executed. | |
1376 | * | |
1377 | * Note that there is no requirement that each message be sent to | |
1378 | * the same slave address, although that is the most common model. | |
1379 | */ | |
09b8ce0a | 1380 | int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) |
1da177e4 | 1381 | { |
b37d2a3a | 1382 | int ret; |
1da177e4 | 1383 | |
a1cdedac DB |
1384 | /* REVISIT the fault reporting model here is weak: |
1385 | * | |
1386 | * - When we get an error after receiving N bytes from a slave, | |
1387 | * there is no way to report "N". | |
1388 | * | |
1389 | * - When we get a NAK after transmitting N bytes to a slave, | |
1390 | * there is no way to report "N" ... or to let the master | |
1391 | * continue executing the rest of this combined message, if | |
1392 | * that's the appropriate response. | |
1393 | * | |
1394 | * - When for example "num" is two and we successfully complete | |
1395 | * the first message but get an error part way through the | |
1396 | * second, it's unclear whether that should be reported as | |
1397 | * one (discarding status on the second message) or errno | |
1398 | * (discarding status on the first one). | |
1399 | */ | |
1400 | ||
1da177e4 LT |
1401 | if (adap->algo->master_xfer) { |
1402 | #ifdef DEBUG | |
1403 | for (ret = 0; ret < num; ret++) { | |
1404 | dev_dbg(&adap->dev, "master_xfer[%d] %c, addr=0x%02x, " | |
209d27c3 JD |
1405 | "len=%d%s\n", ret, (msgs[ret].flags & I2C_M_RD) |
1406 | ? 'R' : 'W', msgs[ret].addr, msgs[ret].len, | |
1407 | (msgs[ret].flags & I2C_M_RECV_LEN) ? "+" : ""); | |
1da177e4 LT |
1408 | } |
1409 | #endif | |
1410 | ||
cea443a8 | 1411 | if (in_atomic() || irqs_disabled()) { |
fe61e07e | 1412 | ret = i2c_trylock_adapter(adap); |
cea443a8 MR |
1413 | if (!ret) |
1414 | /* I2C activity is ongoing. */ | |
1415 | return -EAGAIN; | |
1416 | } else { | |
fe61e07e | 1417 | i2c_lock_adapter(adap); |
cea443a8 MR |
1418 | } |
1419 | ||
b37d2a3a | 1420 | ret = __i2c_transfer(adap, msgs, num); |
fe61e07e | 1421 | i2c_unlock_adapter(adap); |
1da177e4 LT |
1422 | |
1423 | return ret; | |
1424 | } else { | |
1425 | dev_dbg(&adap->dev, "I2C level transfers not supported\n"); | |
24a5bb7b | 1426 | return -EOPNOTSUPP; |
1da177e4 LT |
1427 | } |
1428 | } | |
c0564606 | 1429 | EXPORT_SYMBOL(i2c_transfer); |
1da177e4 | 1430 | |
a1cdedac DB |
1431 | /** |
1432 | * i2c_master_send - issue a single I2C message in master transmit mode | |
1433 | * @client: Handle to slave device | |
1434 | * @buf: Data that will be written to the slave | |
0c43ea54 | 1435 | * @count: How many bytes to write, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1436 | * |
1437 | * Returns negative errno, or else the number of bytes written. | |
1438 | */ | |
0cc43a18 | 1439 | int i2c_master_send(const struct i2c_client *client, const char *buf, int count) |
1da177e4 LT |
1440 | { |
1441 | int ret; | |
7225acf4 | 1442 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1443 | struct i2c_msg msg; |
1444 | ||
815f55f2 JD |
1445 | msg.addr = client->addr; |
1446 | msg.flags = client->flags & I2C_M_TEN; | |
1447 | msg.len = count; | |
1448 | msg.buf = (char *)buf; | |
438d6c2c | 1449 | |
815f55f2 | 1450 | ret = i2c_transfer(adap, &msg, 1); |
1da177e4 | 1451 | |
834aa6f3 WS |
1452 | /* |
1453 | * If everything went ok (i.e. 1 msg transmitted), return #bytes | |
1454 | * transmitted, else error code. | |
1455 | */ | |
815f55f2 | 1456 | return (ret == 1) ? count : ret; |
1da177e4 | 1457 | } |
c0564606 | 1458 | EXPORT_SYMBOL(i2c_master_send); |
1da177e4 | 1459 | |
a1cdedac DB |
1460 | /** |
1461 | * i2c_master_recv - issue a single I2C message in master receive mode | |
1462 | * @client: Handle to slave device | |
1463 | * @buf: Where to store data read from slave | |
0c43ea54 | 1464 | * @count: How many bytes to read, must be less than 64k since msg.len is u16 |
a1cdedac DB |
1465 | * |
1466 | * Returns negative errno, or else the number of bytes read. | |
1467 | */ | |
0cc43a18 | 1468 | int i2c_master_recv(const struct i2c_client *client, char *buf, int count) |
1da177e4 | 1469 | { |
7225acf4 | 1470 | struct i2c_adapter *adap = client->adapter; |
1da177e4 LT |
1471 | struct i2c_msg msg; |
1472 | int ret; | |
815f55f2 JD |
1473 | |
1474 | msg.addr = client->addr; | |
1475 | msg.flags = client->flags & I2C_M_TEN; | |
1476 | msg.flags |= I2C_M_RD; | |
1477 | msg.len = count; | |
1478 | msg.buf = buf; | |
1479 | ||
1480 | ret = i2c_transfer(adap, &msg, 1); | |
1481 | ||
834aa6f3 WS |
1482 | /* |
1483 | * If everything went ok (i.e. 1 msg received), return #bytes received, | |
1484 | * else error code. | |
1485 | */ | |
815f55f2 | 1486 | return (ret == 1) ? count : ret; |
1da177e4 | 1487 | } |
c0564606 | 1488 | EXPORT_SYMBOL(i2c_master_recv); |
1da177e4 | 1489 | |
1da177e4 LT |
1490 | /* ---------------------------------------------------- |
1491 | * the i2c address scanning function | |
1492 | * Will not work for 10-bit addresses! | |
1493 | * ---------------------------------------------------- | |
1494 | */ | |
1da177e4 | 1495 | |
63e4e802 JD |
1496 | /* |
1497 | * Legacy default probe function, mostly relevant for SMBus. The default | |
1498 | * probe method is a quick write, but it is known to corrupt the 24RF08 | |
1499 | * EEPROMs due to a state machine bug, and could also irreversibly | |
1500 | * write-protect some EEPROMs, so for address ranges 0x30-0x37 and 0x50-0x5f, | |
1501 | * we use a short byte read instead. Also, some bus drivers don't implement | |
1502 | * quick write, so we fallback to a byte read in that case too. | |
1503 | * On x86, there is another special case for FSC hardware monitoring chips, | |
1504 | * which want regular byte reads (address 0x73.) Fortunately, these are the | |
1505 | * only known chips using this I2C address on PC hardware. | |
1506 | * Returns 1 if probe succeeded, 0 if not. | |
1507 | */ | |
1508 | static int i2c_default_probe(struct i2c_adapter *adap, unsigned short addr) | |
1509 | { | |
1510 | int err; | |
1511 | union i2c_smbus_data dummy; | |
1512 | ||
1513 | #ifdef CONFIG_X86 | |
1514 | if (addr == 0x73 && (adap->class & I2C_CLASS_HWMON) | |
1515 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE_DATA)) | |
1516 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1517 | I2C_SMBUS_BYTE_DATA, &dummy); | |
1518 | else | |
1519 | #endif | |
8031d79b JD |
1520 | if (!((addr & ~0x07) == 0x30 || (addr & ~0x0f) == 0x50) |
1521 | && i2c_check_functionality(adap, I2C_FUNC_SMBUS_QUICK)) | |
63e4e802 JD |
1522 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_WRITE, 0, |
1523 | I2C_SMBUS_QUICK, NULL); | |
8031d79b JD |
1524 | else if (i2c_check_functionality(adap, I2C_FUNC_SMBUS_READ_BYTE)) |
1525 | err = i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1526 | I2C_SMBUS_BYTE, &dummy); | |
1527 | else { | |
1528 | dev_warn(&adap->dev, "No suitable probing method supported\n"); | |
1529 | err = -EOPNOTSUPP; | |
1530 | } | |
63e4e802 JD |
1531 | |
1532 | return err >= 0; | |
1533 | } | |
1534 | ||
ccfbbd08 | 1535 | static int i2c_detect_address(struct i2c_client *temp_client, |
4735c98f JD |
1536 | struct i2c_driver *driver) |
1537 | { | |
1538 | struct i2c_board_info info; | |
1539 | struct i2c_adapter *adapter = temp_client->adapter; | |
1540 | int addr = temp_client->addr; | |
1541 | int err; | |
1542 | ||
1543 | /* Make sure the address is valid */ | |
656b8761 JD |
1544 | err = i2c_check_addr_validity(addr); |
1545 | if (err) { | |
4735c98f JD |
1546 | dev_warn(&adapter->dev, "Invalid probe address 0x%02x\n", |
1547 | addr); | |
656b8761 | 1548 | return err; |
4735c98f JD |
1549 | } |
1550 | ||
1551 | /* Skip if already in use */ | |
3b5f794b | 1552 | if (i2c_check_addr_busy(adapter, addr)) |
4735c98f JD |
1553 | return 0; |
1554 | ||
ccfbbd08 | 1555 | /* Make sure there is something at this address */ |
63e4e802 JD |
1556 | if (!i2c_default_probe(adapter, addr)) |
1557 | return 0; | |
4735c98f JD |
1558 | |
1559 | /* Finally call the custom detection function */ | |
1560 | memset(&info, 0, sizeof(struct i2c_board_info)); | |
1561 | info.addr = addr; | |
310ec792 | 1562 | err = driver->detect(temp_client, &info); |
4735c98f JD |
1563 | if (err) { |
1564 | /* -ENODEV is returned if the detection fails. We catch it | |
1565 | here as this isn't an error. */ | |
1566 | return err == -ENODEV ? 0 : err; | |
1567 | } | |
1568 | ||
1569 | /* Consistency check */ | |
1570 | if (info.type[0] == '\0') { | |
1571 | dev_err(&adapter->dev, "%s detection function provided " | |
1572 | "no name for 0x%x\n", driver->driver.name, | |
1573 | addr); | |
1574 | } else { | |
1575 | struct i2c_client *client; | |
1576 | ||
1577 | /* Detection succeeded, instantiate the device */ | |
1578 | dev_dbg(&adapter->dev, "Creating %s at 0x%02x\n", | |
1579 | info.type, info.addr); | |
1580 | client = i2c_new_device(adapter, &info); | |
1581 | if (client) | |
1582 | list_add_tail(&client->detected, &driver->clients); | |
1583 | else | |
1584 | dev_err(&adapter->dev, "Failed creating %s at 0x%02x\n", | |
1585 | info.type, info.addr); | |
1586 | } | |
1587 | return 0; | |
1588 | } | |
1589 | ||
1590 | static int i2c_detect(struct i2c_adapter *adapter, struct i2c_driver *driver) | |
1591 | { | |
c3813d6a | 1592 | const unsigned short *address_list; |
4735c98f JD |
1593 | struct i2c_client *temp_client; |
1594 | int i, err = 0; | |
1595 | int adap_id = i2c_adapter_id(adapter); | |
1596 | ||
c3813d6a JD |
1597 | address_list = driver->address_list; |
1598 | if (!driver->detect || !address_list) | |
4735c98f JD |
1599 | return 0; |
1600 | ||
51b54ba9 JD |
1601 | /* Stop here if the classes do not match */ |
1602 | if (!(adapter->class & driver->class)) | |
1603 | return 0; | |
1604 | ||
4735c98f JD |
1605 | /* Set up a temporary client to help detect callback */ |
1606 | temp_client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); | |
1607 | if (!temp_client) | |
1608 | return -ENOMEM; | |
1609 | temp_client->adapter = adapter; | |
1610 | ||
c3813d6a | 1611 | for (i = 0; address_list[i] != I2C_CLIENT_END; i += 1) { |
4735c98f | 1612 | dev_dbg(&adapter->dev, "found normal entry for adapter %d, " |
c3813d6a JD |
1613 | "addr 0x%02x\n", adap_id, address_list[i]); |
1614 | temp_client->addr = address_list[i]; | |
ccfbbd08 | 1615 | err = i2c_detect_address(temp_client, driver); |
51b54ba9 JD |
1616 | if (unlikely(err)) |
1617 | break; | |
4735c98f JD |
1618 | } |
1619 | ||
4735c98f JD |
1620 | kfree(temp_client); |
1621 | return err; | |
1622 | } | |
1623 | ||
d44f19d5 JD |
1624 | int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr) |
1625 | { | |
1626 | return i2c_smbus_xfer(adap, addr, 0, I2C_SMBUS_READ, 0, | |
1627 | I2C_SMBUS_QUICK, NULL) >= 0; | |
1628 | } | |
1629 | EXPORT_SYMBOL_GPL(i2c_probe_func_quick_read); | |
1630 | ||
12b5053a JD |
1631 | struct i2c_client * |
1632 | i2c_new_probed_device(struct i2c_adapter *adap, | |
1633 | struct i2c_board_info *info, | |
9a94241a JD |
1634 | unsigned short const *addr_list, |
1635 | int (*probe)(struct i2c_adapter *, unsigned short addr)) | |
12b5053a JD |
1636 | { |
1637 | int i; | |
1638 | ||
8031d79b | 1639 | if (!probe) |
9a94241a | 1640 | probe = i2c_default_probe; |
12b5053a | 1641 | |
12b5053a JD |
1642 | for (i = 0; addr_list[i] != I2C_CLIENT_END; i++) { |
1643 | /* Check address validity */ | |
656b8761 | 1644 | if (i2c_check_addr_validity(addr_list[i]) < 0) { |
12b5053a JD |
1645 | dev_warn(&adap->dev, "Invalid 7-bit address " |
1646 | "0x%02x\n", addr_list[i]); | |
1647 | continue; | |
1648 | } | |
1649 | ||
1650 | /* Check address availability */ | |
3b5f794b | 1651 | if (i2c_check_addr_busy(adap, addr_list[i])) { |
12b5053a JD |
1652 | dev_dbg(&adap->dev, "Address 0x%02x already in " |
1653 | "use, not probing\n", addr_list[i]); | |
1654 | continue; | |
1655 | } | |
1656 | ||
63e4e802 | 1657 | /* Test address responsiveness */ |
9a94241a | 1658 | if (probe(adap, addr_list[i])) |
63e4e802 | 1659 | break; |
12b5053a | 1660 | } |
12b5053a JD |
1661 | |
1662 | if (addr_list[i] == I2C_CLIENT_END) { | |
1663 | dev_dbg(&adap->dev, "Probing failed, no device found\n"); | |
1664 | return NULL; | |
1665 | } | |
1666 | ||
1667 | info->addr = addr_list[i]; | |
1668 | return i2c_new_device(adap, info); | |
1669 | } | |
1670 | EXPORT_SYMBOL_GPL(i2c_new_probed_device); | |
1671 | ||
d735b34d | 1672 | struct i2c_adapter *i2c_get_adapter(int nr) |
1da177e4 | 1673 | { |
1da177e4 | 1674 | struct i2c_adapter *adapter; |
438d6c2c | 1675 | |
caada32a | 1676 | mutex_lock(&core_lock); |
d735b34d | 1677 | adapter = idr_find(&i2c_adapter_idr, nr); |
a0920e10 MH |
1678 | if (adapter && !try_module_get(adapter->owner)) |
1679 | adapter = NULL; | |
1680 | ||
caada32a | 1681 | mutex_unlock(&core_lock); |
a0920e10 | 1682 | return adapter; |
1da177e4 | 1683 | } |
c0564606 | 1684 | EXPORT_SYMBOL(i2c_get_adapter); |
1da177e4 LT |
1685 | |
1686 | void i2c_put_adapter(struct i2c_adapter *adap) | |
1687 | { | |
1688 | module_put(adap->owner); | |
1689 | } | |
c0564606 | 1690 | EXPORT_SYMBOL(i2c_put_adapter); |
1da177e4 LT |
1691 | |
1692 | /* The SMBus parts */ | |
1693 | ||
438d6c2c | 1694 | #define POLY (0x1070U << 3) |
09b8ce0a | 1695 | static u8 crc8(u16 data) |
1da177e4 LT |
1696 | { |
1697 | int i; | |
438d6c2c | 1698 | |
7225acf4 | 1699 | for (i = 0; i < 8; i++) { |
438d6c2c | 1700 | if (data & 0x8000) |
1da177e4 LT |
1701 | data = data ^ POLY; |
1702 | data = data << 1; | |
1703 | } | |
1704 | return (u8)(data >> 8); | |
1705 | } | |
1706 | ||
421ef47b JD |
1707 | /* Incremental CRC8 over count bytes in the array pointed to by p */ |
1708 | static u8 i2c_smbus_pec(u8 crc, u8 *p, size_t count) | |
1da177e4 LT |
1709 | { |
1710 | int i; | |
1711 | ||
7225acf4 | 1712 | for (i = 0; i < count; i++) |
421ef47b | 1713 | crc = crc8((crc ^ p[i]) << 8); |
1da177e4 LT |
1714 | return crc; |
1715 | } | |
1716 | ||
421ef47b JD |
1717 | /* Assume a 7-bit address, which is reasonable for SMBus */ |
1718 | static u8 i2c_smbus_msg_pec(u8 pec, struct i2c_msg *msg) | |
1da177e4 | 1719 | { |
421ef47b JD |
1720 | /* The address will be sent first */ |
1721 | u8 addr = (msg->addr << 1) | !!(msg->flags & I2C_M_RD); | |
1722 | pec = i2c_smbus_pec(pec, &addr, 1); | |
1723 | ||
1724 | /* The data buffer follows */ | |
1725 | return i2c_smbus_pec(pec, msg->buf, msg->len); | |
1da177e4 LT |
1726 | } |
1727 | ||
421ef47b JD |
1728 | /* Used for write only transactions */ |
1729 | static inline void i2c_smbus_add_pec(struct i2c_msg *msg) | |
1da177e4 | 1730 | { |
421ef47b JD |
1731 | msg->buf[msg->len] = i2c_smbus_msg_pec(0, msg); |
1732 | msg->len++; | |
1da177e4 LT |
1733 | } |
1734 | ||
421ef47b JD |
1735 | /* Return <0 on CRC error |
1736 | If there was a write before this read (most cases) we need to take the | |
1737 | partial CRC from the write part into account. | |
1738 | Note that this function does modify the message (we need to decrease the | |
1739 | message length to hide the CRC byte from the caller). */ | |
1740 | static int i2c_smbus_check_pec(u8 cpec, struct i2c_msg *msg) | |
1da177e4 | 1741 | { |
421ef47b JD |
1742 | u8 rpec = msg->buf[--msg->len]; |
1743 | cpec = i2c_smbus_msg_pec(cpec, msg); | |
1da177e4 | 1744 | |
1da177e4 LT |
1745 | if (rpec != cpec) { |
1746 | pr_debug("i2c-core: Bad PEC 0x%02x vs. 0x%02x\n", | |
1747 | rpec, cpec); | |
24a5bb7b | 1748 | return -EBADMSG; |
1da177e4 | 1749 | } |
438d6c2c | 1750 | return 0; |
1da177e4 LT |
1751 | } |
1752 | ||
a1cdedac DB |
1753 | /** |
1754 | * i2c_smbus_read_byte - SMBus "receive byte" protocol | |
1755 | * @client: Handle to slave device | |
1756 | * | |
1757 | * This executes the SMBus "receive byte" protocol, returning negative errno | |
1758 | * else the byte received from the device. | |
1759 | */ | |
0cc43a18 | 1760 | s32 i2c_smbus_read_byte(const struct i2c_client *client) |
1da177e4 LT |
1761 | { |
1762 | union i2c_smbus_data data; | |
24a5bb7b DB |
1763 | int status; |
1764 | ||
1765 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1766 | I2C_SMBUS_READ, 0, | |
1767 | I2C_SMBUS_BYTE, &data); | |
1768 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1769 | } |
c0564606 | 1770 | EXPORT_SYMBOL(i2c_smbus_read_byte); |
1da177e4 | 1771 | |
a1cdedac DB |
1772 | /** |
1773 | * i2c_smbus_write_byte - SMBus "send byte" protocol | |
1774 | * @client: Handle to slave device | |
1775 | * @value: Byte to be sent | |
1776 | * | |
1777 | * This executes the SMBus "send byte" protocol, returning negative errno | |
1778 | * else zero on success. | |
1779 | */ | |
0cc43a18 | 1780 | s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value) |
1da177e4 | 1781 | { |
7225acf4 | 1782 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
421ef47b | 1783 | I2C_SMBUS_WRITE, value, I2C_SMBUS_BYTE, NULL); |
1da177e4 | 1784 | } |
c0564606 | 1785 | EXPORT_SYMBOL(i2c_smbus_write_byte); |
1da177e4 | 1786 | |
a1cdedac DB |
1787 | /** |
1788 | * i2c_smbus_read_byte_data - SMBus "read byte" protocol | |
1789 | * @client: Handle to slave device | |
1790 | * @command: Byte interpreted by slave | |
1791 | * | |
1792 | * This executes the SMBus "read byte" protocol, returning negative errno | |
1793 | * else a data byte received from the device. | |
1794 | */ | |
0cc43a18 | 1795 | s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
1796 | { |
1797 | union i2c_smbus_data data; | |
24a5bb7b DB |
1798 | int status; |
1799 | ||
1800 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1801 | I2C_SMBUS_READ, command, | |
1802 | I2C_SMBUS_BYTE_DATA, &data); | |
1803 | return (status < 0) ? status : data.byte; | |
1da177e4 | 1804 | } |
c0564606 | 1805 | EXPORT_SYMBOL(i2c_smbus_read_byte_data); |
1da177e4 | 1806 | |
a1cdedac DB |
1807 | /** |
1808 | * i2c_smbus_write_byte_data - SMBus "write byte" protocol | |
1809 | * @client: Handle to slave device | |
1810 | * @command: Byte interpreted by slave | |
1811 | * @value: Byte being written | |
1812 | * | |
1813 | * This executes the SMBus "write byte" protocol, returning negative errno | |
1814 | * else zero on success. | |
1815 | */ | |
0cc43a18 JD |
1816 | s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, |
1817 | u8 value) | |
1da177e4 LT |
1818 | { |
1819 | union i2c_smbus_data data; | |
1820 | data.byte = value; | |
7225acf4 FH |
1821 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1822 | I2C_SMBUS_WRITE, command, | |
1823 | I2C_SMBUS_BYTE_DATA, &data); | |
1da177e4 | 1824 | } |
c0564606 | 1825 | EXPORT_SYMBOL(i2c_smbus_write_byte_data); |
1da177e4 | 1826 | |
a1cdedac DB |
1827 | /** |
1828 | * i2c_smbus_read_word_data - SMBus "read word" protocol | |
1829 | * @client: Handle to slave device | |
1830 | * @command: Byte interpreted by slave | |
1831 | * | |
1832 | * This executes the SMBus "read word" protocol, returning negative errno | |
1833 | * else a 16-bit unsigned "word" received from the device. | |
1834 | */ | |
0cc43a18 | 1835 | s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command) |
1da177e4 LT |
1836 | { |
1837 | union i2c_smbus_data data; | |
24a5bb7b DB |
1838 | int status; |
1839 | ||
1840 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1841 | I2C_SMBUS_READ, command, | |
1842 | I2C_SMBUS_WORD_DATA, &data); | |
1843 | return (status < 0) ? status : data.word; | |
1da177e4 | 1844 | } |
c0564606 | 1845 | EXPORT_SYMBOL(i2c_smbus_read_word_data); |
1da177e4 | 1846 | |
a1cdedac DB |
1847 | /** |
1848 | * i2c_smbus_write_word_data - SMBus "write word" protocol | |
1849 | * @client: Handle to slave device | |
1850 | * @command: Byte interpreted by slave | |
1851 | * @value: 16-bit "word" being written | |
1852 | * | |
1853 | * This executes the SMBus "write word" protocol, returning negative errno | |
1854 | * else zero on success. | |
1855 | */ | |
0cc43a18 JD |
1856 | s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, |
1857 | u16 value) | |
1da177e4 LT |
1858 | { |
1859 | union i2c_smbus_data data; | |
1860 | data.word = value; | |
7225acf4 FH |
1861 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1862 | I2C_SMBUS_WRITE, command, | |
1863 | I2C_SMBUS_WORD_DATA, &data); | |
1da177e4 | 1864 | } |
c0564606 | 1865 | EXPORT_SYMBOL(i2c_smbus_write_word_data); |
1da177e4 | 1866 | |
a64ec07d | 1867 | /** |
a1cdedac | 1868 | * i2c_smbus_read_block_data - SMBus "block read" protocol |
a64ec07d | 1869 | * @client: Handle to slave device |
a1cdedac | 1870 | * @command: Byte interpreted by slave |
a64ec07d DB |
1871 | * @values: Byte array into which data will be read; big enough to hold |
1872 | * the data returned by the slave. SMBus allows at most 32 bytes. | |
1873 | * | |
a1cdedac DB |
1874 | * This executes the SMBus "block read" protocol, returning negative errno |
1875 | * else the number of data bytes in the slave's response. | |
a64ec07d DB |
1876 | * |
1877 | * Note that using this function requires that the client's adapter support | |
1878 | * the I2C_FUNC_SMBUS_READ_BLOCK_DATA functionality. Not all adapter drivers | |
1879 | * support this; its emulation through I2C messaging relies on a specific | |
1880 | * mechanism (I2C_M_RECV_LEN) which may not be implemented. | |
1881 | */ | |
0cc43a18 | 1882 | s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, |
b86a1bc8 JD |
1883 | u8 *values) |
1884 | { | |
1885 | union i2c_smbus_data data; | |
24a5bb7b | 1886 | int status; |
b86a1bc8 | 1887 | |
24a5bb7b DB |
1888 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1889 | I2C_SMBUS_READ, command, | |
1890 | I2C_SMBUS_BLOCK_DATA, &data); | |
1891 | if (status) | |
1892 | return status; | |
b86a1bc8 JD |
1893 | |
1894 | memcpy(values, &data.block[1], data.block[0]); | |
1895 | return data.block[0]; | |
1896 | } | |
1897 | EXPORT_SYMBOL(i2c_smbus_read_block_data); | |
1898 | ||
a1cdedac DB |
1899 | /** |
1900 | * i2c_smbus_write_block_data - SMBus "block write" protocol | |
1901 | * @client: Handle to slave device | |
1902 | * @command: Byte interpreted by slave | |
1903 | * @length: Size of data block; SMBus allows at most 32 bytes | |
1904 | * @values: Byte array which will be written. | |
1905 | * | |
1906 | * This executes the SMBus "block write" protocol, returning negative errno | |
1907 | * else zero on success. | |
1908 | */ | |
0cc43a18 | 1909 | s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 1910 | u8 length, const u8 *values) |
1da177e4 LT |
1911 | { |
1912 | union i2c_smbus_data data; | |
7656032b | 1913 | |
1da177e4 LT |
1914 | if (length > I2C_SMBUS_BLOCK_MAX) |
1915 | length = I2C_SMBUS_BLOCK_MAX; | |
1da177e4 | 1916 | data.block[0] = length; |
7656032b | 1917 | memcpy(&data.block[1], values, length); |
7225acf4 FH |
1918 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1919 | I2C_SMBUS_WRITE, command, | |
1920 | I2C_SMBUS_BLOCK_DATA, &data); | |
1da177e4 | 1921 | } |
c0564606 | 1922 | EXPORT_SYMBOL(i2c_smbus_write_block_data); |
1da177e4 LT |
1923 | |
1924 | /* Returns the number of read bytes */ | |
0cc43a18 | 1925 | s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, |
4b2643d7 | 1926 | u8 length, u8 *values) |
1da177e4 LT |
1927 | { |
1928 | union i2c_smbus_data data; | |
24a5bb7b | 1929 | int status; |
7656032b | 1930 | |
4b2643d7 JD |
1931 | if (length > I2C_SMBUS_BLOCK_MAX) |
1932 | length = I2C_SMBUS_BLOCK_MAX; | |
1933 | data.block[0] = length; | |
24a5bb7b DB |
1934 | status = i2c_smbus_xfer(client->adapter, client->addr, client->flags, |
1935 | I2C_SMBUS_READ, command, | |
1936 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1937 | if (status < 0) | |
1938 | return status; | |
7656032b JD |
1939 | |
1940 | memcpy(values, &data.block[1], data.block[0]); | |
1941 | return data.block[0]; | |
1da177e4 | 1942 | } |
c0564606 | 1943 | EXPORT_SYMBOL(i2c_smbus_read_i2c_block_data); |
1da177e4 | 1944 | |
0cc43a18 | 1945 | s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, |
46f5ed75 | 1946 | u8 length, const u8 *values) |
21bbd691 JD |
1947 | { |
1948 | union i2c_smbus_data data; | |
1949 | ||
1950 | if (length > I2C_SMBUS_BLOCK_MAX) | |
1951 | length = I2C_SMBUS_BLOCK_MAX; | |
1952 | data.block[0] = length; | |
1953 | memcpy(data.block + 1, values, length); | |
1954 | return i2c_smbus_xfer(client->adapter, client->addr, client->flags, | |
1955 | I2C_SMBUS_WRITE, command, | |
1956 | I2C_SMBUS_I2C_BLOCK_DATA, &data); | |
1957 | } | |
c0564606 | 1958 | EXPORT_SYMBOL(i2c_smbus_write_i2c_block_data); |
21bbd691 | 1959 | |
438d6c2c | 1960 | /* Simulate a SMBus command using the i2c protocol |
1da177e4 | 1961 | No checking of parameters is done! */ |
7225acf4 FH |
1962 | static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr, |
1963 | unsigned short flags, | |
1964 | char read_write, u8 command, int size, | |
1965 | union i2c_smbus_data *data) | |
1da177e4 LT |
1966 | { |
1967 | /* So we need to generate a series of msgs. In the case of writing, we | |
1968 | need to use only one message; when reading, we need two. We initialize | |
1969 | most things with sane defaults, to keep the code below somewhat | |
1970 | simpler. */ | |
5c50d188 HI |
1971 | unsigned char msgbuf0[I2C_SMBUS_BLOCK_MAX+3]; |
1972 | unsigned char msgbuf1[I2C_SMBUS_BLOCK_MAX+2]; | |
7225acf4 | 1973 | int num = read_write == I2C_SMBUS_READ ? 2 : 1; |
1da177e4 | 1974 | int i; |
421ef47b | 1975 | u8 partial_pec = 0; |
24a5bb7b | 1976 | int status; |
230da094 S |
1977 | struct i2c_msg msg[2] = { |
1978 | { | |
1979 | .addr = addr, | |
1980 | .flags = flags, | |
1981 | .len = 1, | |
1982 | .buf = msgbuf0, | |
1983 | }, { | |
1984 | .addr = addr, | |
1985 | .flags = flags | I2C_M_RD, | |
1986 | .len = 0, | |
1987 | .buf = msgbuf1, | |
1988 | }, | |
1989 | }; | |
1da177e4 LT |
1990 | |
1991 | msgbuf0[0] = command; | |
7225acf4 | 1992 | switch (size) { |
1da177e4 LT |
1993 | case I2C_SMBUS_QUICK: |
1994 | msg[0].len = 0; | |
1995 | /* Special case: The read/write field is used as data */ | |
f29d2e02 RK |
1996 | msg[0].flags = flags | (read_write == I2C_SMBUS_READ ? |
1997 | I2C_M_RD : 0); | |
1da177e4 LT |
1998 | num = 1; |
1999 | break; | |
2000 | case I2C_SMBUS_BYTE: | |
2001 | if (read_write == I2C_SMBUS_READ) { | |
2002 | /* Special case: only a read! */ | |
2003 | msg[0].flags = I2C_M_RD | flags; | |
2004 | num = 1; | |
2005 | } | |
2006 | break; | |
2007 | case I2C_SMBUS_BYTE_DATA: | |
2008 | if (read_write == I2C_SMBUS_READ) | |
2009 | msg[1].len = 1; | |
2010 | else { | |
2011 | msg[0].len = 2; | |
2012 | msgbuf0[1] = data->byte; | |
2013 | } | |
2014 | break; | |
2015 | case I2C_SMBUS_WORD_DATA: | |
2016 | if (read_write == I2C_SMBUS_READ) | |
2017 | msg[1].len = 2; | |
2018 | else { | |
7225acf4 | 2019 | msg[0].len = 3; |
1da177e4 | 2020 | msgbuf0[1] = data->word & 0xff; |
7eff82c8 | 2021 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2022 | } |
2023 | break; | |
2024 | case I2C_SMBUS_PROC_CALL: | |
2025 | num = 2; /* Special case */ | |
2026 | read_write = I2C_SMBUS_READ; | |
2027 | msg[0].len = 3; | |
2028 | msg[1].len = 2; | |
2029 | msgbuf0[1] = data->word & 0xff; | |
7eff82c8 | 2030 | msgbuf0[2] = data->word >> 8; |
1da177e4 LT |
2031 | break; |
2032 | case I2C_SMBUS_BLOCK_DATA: | |
1da177e4 | 2033 | if (read_write == I2C_SMBUS_READ) { |
209d27c3 JD |
2034 | msg[1].flags |= I2C_M_RECV_LEN; |
2035 | msg[1].len = 1; /* block length will be added by | |
2036 | the underlying bus driver */ | |
1da177e4 LT |
2037 | } else { |
2038 | msg[0].len = data->block[0] + 2; | |
2039 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 2) { | |
24a5bb7b DB |
2040 | dev_err(&adapter->dev, |
2041 | "Invalid block write size %d\n", | |
2042 | data->block[0]); | |
2043 | return -EINVAL; | |
1da177e4 | 2044 | } |
5c50d188 | 2045 | for (i = 1; i < msg[0].len; i++) |
1da177e4 LT |
2046 | msgbuf0[i] = data->block[i-1]; |
2047 | } | |
2048 | break; | |
2049 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
209d27c3 JD |
2050 | num = 2; /* Another special case */ |
2051 | read_write = I2C_SMBUS_READ; | |
2052 | if (data->block[0] > I2C_SMBUS_BLOCK_MAX) { | |
24a5bb7b DB |
2053 | dev_err(&adapter->dev, |
2054 | "Invalid block write size %d\n", | |
209d27c3 | 2055 | data->block[0]); |
24a5bb7b | 2056 | return -EINVAL; |
209d27c3 JD |
2057 | } |
2058 | msg[0].len = data->block[0] + 2; | |
2059 | for (i = 1; i < msg[0].len; i++) | |
2060 | msgbuf0[i] = data->block[i-1]; | |
2061 | msg[1].flags |= I2C_M_RECV_LEN; | |
2062 | msg[1].len = 1; /* block length will be added by | |
2063 | the underlying bus driver */ | |
2064 | break; | |
1da177e4 LT |
2065 | case I2C_SMBUS_I2C_BLOCK_DATA: |
2066 | if (read_write == I2C_SMBUS_READ) { | |
4b2643d7 | 2067 | msg[1].len = data->block[0]; |
1da177e4 LT |
2068 | } else { |
2069 | msg[0].len = data->block[0] + 1; | |
30dac746 | 2070 | if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) { |
24a5bb7b DB |
2071 | dev_err(&adapter->dev, |
2072 | "Invalid block write size %d\n", | |
2073 | data->block[0]); | |
2074 | return -EINVAL; | |
1da177e4 LT |
2075 | } |
2076 | for (i = 1; i <= data->block[0]; i++) | |
2077 | msgbuf0[i] = data->block[i]; | |
2078 | } | |
2079 | break; | |
2080 | default: | |
24a5bb7b DB |
2081 | dev_err(&adapter->dev, "Unsupported transaction %d\n", size); |
2082 | return -EOPNOTSUPP; | |
1da177e4 LT |
2083 | } |
2084 | ||
421ef47b JD |
2085 | i = ((flags & I2C_CLIENT_PEC) && size != I2C_SMBUS_QUICK |
2086 | && size != I2C_SMBUS_I2C_BLOCK_DATA); | |
2087 | if (i) { | |
2088 | /* Compute PEC if first message is a write */ | |
2089 | if (!(msg[0].flags & I2C_M_RD)) { | |
438d6c2c | 2090 | if (num == 1) /* Write only */ |
421ef47b JD |
2091 | i2c_smbus_add_pec(&msg[0]); |
2092 | else /* Write followed by read */ | |
2093 | partial_pec = i2c_smbus_msg_pec(0, &msg[0]); | |
2094 | } | |
2095 | /* Ask for PEC if last message is a read */ | |
2096 | if (msg[num-1].flags & I2C_M_RD) | |
438d6c2c | 2097 | msg[num-1].len++; |
421ef47b JD |
2098 | } |
2099 | ||
24a5bb7b DB |
2100 | status = i2c_transfer(adapter, msg, num); |
2101 | if (status < 0) | |
2102 | return status; | |
1da177e4 | 2103 | |
421ef47b JD |
2104 | /* Check PEC if last message is a read */ |
2105 | if (i && (msg[num-1].flags & I2C_M_RD)) { | |
24a5bb7b DB |
2106 | status = i2c_smbus_check_pec(partial_pec, &msg[num-1]); |
2107 | if (status < 0) | |
2108 | return status; | |
421ef47b JD |
2109 | } |
2110 | ||
1da177e4 | 2111 | if (read_write == I2C_SMBUS_READ) |
7225acf4 FH |
2112 | switch (size) { |
2113 | case I2C_SMBUS_BYTE: | |
2114 | data->byte = msgbuf0[0]; | |
2115 | break; | |
2116 | case I2C_SMBUS_BYTE_DATA: | |
2117 | data->byte = msgbuf1[0]; | |
2118 | break; | |
2119 | case I2C_SMBUS_WORD_DATA: | |
2120 | case I2C_SMBUS_PROC_CALL: | |
2121 | data->word = msgbuf1[0] | (msgbuf1[1] << 8); | |
2122 | break; | |
2123 | case I2C_SMBUS_I2C_BLOCK_DATA: | |
2124 | for (i = 0; i < data->block[0]; i++) | |
2125 | data->block[i+1] = msgbuf1[i]; | |
2126 | break; | |
2127 | case I2C_SMBUS_BLOCK_DATA: | |
2128 | case I2C_SMBUS_BLOCK_PROC_CALL: | |
2129 | for (i = 0; i < msgbuf1[0] + 1; i++) | |
2130 | data->block[i] = msgbuf1[i]; | |
2131 | break; | |
1da177e4 LT |
2132 | } |
2133 | return 0; | |
2134 | } | |
2135 | ||
a1cdedac DB |
2136 | /** |
2137 | * i2c_smbus_xfer - execute SMBus protocol operations | |
2138 | * @adapter: Handle to I2C bus | |
2139 | * @addr: Address of SMBus slave on that bus | |
2140 | * @flags: I2C_CLIENT_* flags (usually zero or I2C_CLIENT_PEC) | |
2141 | * @read_write: I2C_SMBUS_READ or I2C_SMBUS_WRITE | |
2142 | * @command: Byte interpreted by slave, for protocols which use such bytes | |
2143 | * @protocol: SMBus protocol operation to execute, such as I2C_SMBUS_PROC_CALL | |
2144 | * @data: Data to be read or written | |
2145 | * | |
2146 | * This executes an SMBus protocol operation, and returns a negative | |
2147 | * errno code else zero on success. | |
2148 | */ | |
09b8ce0a | 2149 | s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, |
a1cdedac | 2150 | char read_write, u8 command, int protocol, |
09b8ce0a | 2151 | union i2c_smbus_data *data) |
1da177e4 | 2152 | { |
66b650f0 CW |
2153 | unsigned long orig_jiffies; |
2154 | int try; | |
1da177e4 | 2155 | s32 res; |
1da177e4 | 2156 | |
d47726c5 | 2157 | flags &= I2C_M_TEN | I2C_CLIENT_PEC | I2C_CLIENT_SCCB; |
1da177e4 LT |
2158 | |
2159 | if (adapter->algo->smbus_xfer) { | |
fe61e07e | 2160 | i2c_lock_adapter(adapter); |
66b650f0 CW |
2161 | |
2162 | /* Retry automatically on arbitration loss */ | |
2163 | orig_jiffies = jiffies; | |
2164 | for (res = 0, try = 0; try <= adapter->retries; try++) { | |
2165 | res = adapter->algo->smbus_xfer(adapter, addr, flags, | |
2166 | read_write, command, | |
2167 | protocol, data); | |
2168 | if (res != -EAGAIN) | |
2169 | break; | |
2170 | if (time_after(jiffies, | |
2171 | orig_jiffies + adapter->timeout)) | |
2172 | break; | |
2173 | } | |
fe61e07e | 2174 | i2c_unlock_adapter(adapter); |
1da177e4 | 2175 | |
72fc2c7f LP |
2176 | if (res != -EOPNOTSUPP || !adapter->algo->master_xfer) |
2177 | return res; | |
2178 | /* | |
2179 | * Fall back to i2c_smbus_xfer_emulated if the adapter doesn't | |
2180 | * implement native support for the SMBus operation. | |
2181 | */ | |
2182 | } | |
2183 | ||
2184 | return i2c_smbus_xfer_emulated(adapter, addr, flags, read_write, | |
2185 | command, protocol, data); | |
1da177e4 | 2186 | } |
1da177e4 | 2187 | EXPORT_SYMBOL(i2c_smbus_xfer); |
1da177e4 LT |
2188 | |
2189 | MODULE_AUTHOR("Simon G. Vogl <simon@tk.uni-linz.ac.at>"); | |
2190 | MODULE_DESCRIPTION("I2C-Bus main module"); | |
2191 | MODULE_LICENSE("GPL"); |