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1 | /* ------------------------------------------------------------------------- */ | |
2 | /* */ | |
3 | /* i2c.h - definitions for the i2c-bus interface */ | |
4 | /* */ | |
5 | /* ------------------------------------------------------------------------- */ | |
6 | /* Copyright (C) 1995-2000 Simon G. Vogl | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
10 | the Free Software Foundation; either version 2 of the License, or | |
11 | (at your option) any later version. | |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with this program; if not, write to the Free Software | |
20 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
21 | /* ------------------------------------------------------------------------- */ | |
22 | ||
23 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and | |
24 | Frodo Looijaard <frodol@dds.nl> */ | |
25 | ||
26 | #ifndef _LINUX_I2C_H | |
27 | #define _LINUX_I2C_H | |
28 | ||
29 | #include <linux/types.h> | |
30 | #ifdef __KERNEL__ | |
31 | #include <linux/module.h> | |
32 | #include <linux/i2c-id.h> | |
33 | #include <linux/mod_devicetable.h> | |
34 | #include <linux/device.h> /* for struct device */ | |
35 | #include <linux/sched.h> /* for completion */ | |
36 | #include <linux/mutex.h> | |
37 | #include <linux/of.h> /* for struct device_node */ | |
38 | ||
39 | extern struct bus_type i2c_bus_type; | |
40 | extern struct device_type i2c_adapter_type; | |
41 | ||
42 | /* --- General options ------------------------------------------------ */ | |
43 | ||
44 | struct i2c_msg; | |
45 | struct i2c_algorithm; | |
46 | struct i2c_adapter; | |
47 | struct i2c_client; | |
48 | struct i2c_driver; | |
49 | union i2c_smbus_data; | |
50 | struct i2c_board_info; | |
51 | ||
52 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
53 | /* | |
54 | * The master routines are the ones normally used to transmit data to devices | |
55 | * on a bus (or read from them). Apart from two basic transfer functions to | |
56 | * transmit one message at a time, a more complex version can be used to | |
57 | * transmit an arbitrary number of messages without interruption. | |
58 | * @count must be be less than 64k since msg.len is u16. | |
59 | */ | |
60 | extern int i2c_master_send(struct i2c_client *client, const char *buf, | |
61 | int count); | |
62 | extern int i2c_master_recv(struct i2c_client *client, char *buf, int count); | |
63 | ||
64 | /* Transfer num messages. | |
65 | */ | |
66 | extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
67 | int num); | |
68 | ||
69 | /* This is the very generalized SMBus access routine. You probably do not | |
70 | want to use this, though; one of the functions below may be much easier, | |
71 | and probably just as fast. | |
72 | Note that we use i2c_adapter here, because you do not need a specific | |
73 | smbus adapter to call this function. */ | |
74 | extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, | |
75 | unsigned short flags, char read_write, u8 command, | |
76 | int size, union i2c_smbus_data *data); | |
77 | ||
78 | /* Now follow the 'nice' access routines. These also document the calling | |
79 | conventions of i2c_smbus_xfer. */ | |
80 | ||
81 | extern s32 i2c_smbus_read_byte(struct i2c_client *client); | |
82 | extern s32 i2c_smbus_write_byte(struct i2c_client *client, u8 value); | |
83 | extern s32 i2c_smbus_read_byte_data(struct i2c_client *client, u8 command); | |
84 | extern s32 i2c_smbus_write_byte_data(struct i2c_client *client, | |
85 | u8 command, u8 value); | |
86 | extern s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command); | |
87 | extern s32 i2c_smbus_write_word_data(struct i2c_client *client, | |
88 | u8 command, u16 value); | |
89 | /* Returns the number of read bytes */ | |
90 | extern s32 i2c_smbus_read_block_data(struct i2c_client *client, | |
91 | u8 command, u8 *values); | |
92 | extern s32 i2c_smbus_write_block_data(struct i2c_client *client, | |
93 | u8 command, u8 length, const u8 *values); | |
94 | /* Returns the number of read bytes */ | |
95 | extern s32 i2c_smbus_read_i2c_block_data(struct i2c_client *client, | |
96 | u8 command, u8 length, u8 *values); | |
97 | extern s32 i2c_smbus_write_i2c_block_data(struct i2c_client *client, | |
98 | u8 command, u8 length, | |
99 | const u8 *values); | |
100 | #endif /* I2C */ | |
101 | ||
102 | /** | |
103 | * struct i2c_driver - represent an I2C device driver | |
104 | * @class: What kind of i2c device we instantiate (for detect) | |
105 | * @attach_adapter: Callback for bus addition (for legacy drivers) | |
106 | * @detach_adapter: Callback for bus removal (for legacy drivers) | |
107 | * @probe: Callback for device binding | |
108 | * @remove: Callback for device unbinding | |
109 | * @shutdown: Callback for device shutdown | |
110 | * @suspend: Callback for device suspend | |
111 | * @resume: Callback for device resume | |
112 | * @alert: Alert callback, for example for the SMBus alert protocol | |
113 | * @command: Callback for bus-wide signaling (optional) | |
114 | * @driver: Device driver model driver | |
115 | * @id_table: List of I2C devices supported by this driver | |
116 | * @detect: Callback for device detection | |
117 | * @address_list: The I2C addresses to probe (for detect) | |
118 | * @clients: List of detected clients we created (for i2c-core use only) | |
119 | * | |
120 | * The driver.owner field should be set to the module owner of this driver. | |
121 | * The driver.name field should be set to the name of this driver. | |
122 | * | |
123 | * For automatic device detection, both @detect and @address_data must | |
124 | * be defined. @class should also be set, otherwise only devices forced | |
125 | * with module parameters will be created. The detect function must | |
126 | * fill at least the name field of the i2c_board_info structure it is | |
127 | * handed upon successful detection, and possibly also the flags field. | |
128 | * | |
129 | * If @detect is missing, the driver will still work fine for enumerated | |
130 | * devices. Detected devices simply won't be supported. This is expected | |
131 | * for the many I2C/SMBus devices which can't be detected reliably, and | |
132 | * the ones which can always be enumerated in practice. | |
133 | * | |
134 | * The i2c_client structure which is handed to the @detect callback is | |
135 | * not a real i2c_client. It is initialized just enough so that you can | |
136 | * call i2c_smbus_read_byte_data and friends on it. Don't do anything | |
137 | * else with it. In particular, calling dev_dbg and friends on it is | |
138 | * not allowed. | |
139 | */ | |
140 | struct i2c_driver { | |
141 | unsigned int class; | |
142 | ||
143 | /* Notifies the driver that a new bus has appeared or is about to be | |
144 | * removed. You should avoid using this if you can, it will probably | |
145 | * be removed in a near future. | |
146 | */ | |
147 | int (*attach_adapter)(struct i2c_adapter *); | |
148 | int (*detach_adapter)(struct i2c_adapter *); | |
149 | ||
150 | /* Standard driver model interfaces */ | |
151 | int (*probe)(struct i2c_client *, const struct i2c_device_id *); | |
152 | int (*remove)(struct i2c_client *); | |
153 | ||
154 | /* driver model interfaces that don't relate to enumeration */ | |
155 | void (*shutdown)(struct i2c_client *); | |
156 | int (*suspend)(struct i2c_client *, pm_message_t mesg); | |
157 | int (*resume)(struct i2c_client *); | |
158 | ||
159 | /* Alert callback, for example for the SMBus alert protocol. | |
160 | * The format and meaning of the data value depends on the protocol. | |
161 | * For the SMBus alert protocol, there is a single bit of data passed | |
162 | * as the alert response's low bit ("event flag"). | |
163 | */ | |
164 | void (*alert)(struct i2c_client *, unsigned int data); | |
165 | ||
166 | /* a ioctl like command that can be used to perform specific functions | |
167 | * with the device. | |
168 | */ | |
169 | int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); | |
170 | ||
171 | struct device_driver driver; | |
172 | const struct i2c_device_id *id_table; | |
173 | ||
174 | /* Device detection callback for automatic device creation */ | |
175 | int (*detect)(struct i2c_client *, struct i2c_board_info *); | |
176 | const unsigned short *address_list; | |
177 | struct list_head clients; | |
178 | }; | |
179 | #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) | |
180 | ||
181 | /** | |
182 | * struct i2c_client - represent an I2C slave device | |
183 | * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; | |
184 | * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking | |
185 | * @addr: Address used on the I2C bus connected to the parent adapter. | |
186 | * @name: Indicates the type of the device, usually a chip name that's | |
187 | * generic enough to hide second-sourcing and compatible revisions. | |
188 | * @adapter: manages the bus segment hosting this I2C device | |
189 | * @driver: device's driver, hence pointer to access routines | |
190 | * @dev: Driver model device node for the slave. | |
191 | * @irq: indicates the IRQ generated by this device (if any) | |
192 | * @detected: member of an i2c_driver.clients list or i2c-core's | |
193 | * userspace_devices list | |
194 | * | |
195 | * An i2c_client identifies a single device (i.e. chip) connected to an | |
196 | * i2c bus. The behaviour exposed to Linux is defined by the driver | |
197 | * managing the device. | |
198 | */ | |
199 | struct i2c_client { | |
200 | unsigned short flags; /* div., see below */ | |
201 | unsigned short addr; /* chip address - NOTE: 7bit */ | |
202 | /* addresses are stored in the */ | |
203 | /* _LOWER_ 7 bits */ | |
204 | char name[I2C_NAME_SIZE]; | |
205 | struct i2c_adapter *adapter; /* the adapter we sit on */ | |
206 | struct i2c_driver *driver; /* and our access routines */ | |
207 | struct device dev; /* the device structure */ | |
208 | int irq; /* irq issued by device */ | |
209 | struct list_head detected; | |
210 | }; | |
211 | #define to_i2c_client(d) container_of(d, struct i2c_client, dev) | |
212 | ||
213 | extern struct i2c_client *i2c_verify_client(struct device *dev); | |
214 | ||
215 | static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) | |
216 | { | |
217 | struct device * const dev = container_of(kobj, struct device, kobj); | |
218 | return to_i2c_client(dev); | |
219 | } | |
220 | ||
221 | static inline void *i2c_get_clientdata(const struct i2c_client *dev) | |
222 | { | |
223 | return dev_get_drvdata(&dev->dev); | |
224 | } | |
225 | ||
226 | static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) | |
227 | { | |
228 | dev_set_drvdata(&dev->dev, data); | |
229 | } | |
230 | ||
231 | /** | |
232 | * struct i2c_board_info - template for device creation | |
233 | * @type: chip type, to initialize i2c_client.name | |
234 | * @flags: to initialize i2c_client.flags | |
235 | * @addr: stored in i2c_client.addr | |
236 | * @platform_data: stored in i2c_client.dev.platform_data | |
237 | * @archdata: copied into i2c_client.dev.archdata | |
238 | * @of_node: pointer to OpenFirmware device node | |
239 | * @irq: stored in i2c_client.irq | |
240 | * | |
241 | * I2C doesn't actually support hardware probing, although controllers and | |
242 | * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's | |
243 | * a device at a given address. Drivers commonly need more information than | |
244 | * that, such as chip type, configuration, associated IRQ, and so on. | |
245 | * | |
246 | * i2c_board_info is used to build tables of information listing I2C devices | |
247 | * that are present. This information is used to grow the driver model tree. | |
248 | * For mainboards this is done statically using i2c_register_board_info(); | |
249 | * bus numbers identify adapters that aren't yet available. For add-on boards, | |
250 | * i2c_new_device() does this dynamically with the adapter already known. | |
251 | */ | |
252 | struct i2c_board_info { | |
253 | char type[I2C_NAME_SIZE]; | |
254 | unsigned short flags; | |
255 | unsigned short addr; | |
256 | void *platform_data; | |
257 | struct dev_archdata *archdata; | |
258 | #ifdef CONFIG_OF | |
259 | struct device_node *of_node; | |
260 | #endif | |
261 | int irq; | |
262 | }; | |
263 | ||
264 | /** | |
265 | * I2C_BOARD_INFO - macro used to list an i2c device and its address | |
266 | * @dev_type: identifies the device type | |
267 | * @dev_addr: the device's address on the bus. | |
268 | * | |
269 | * This macro initializes essential fields of a struct i2c_board_info, | |
270 | * declaring what has been provided on a particular board. Optional | |
271 | * fields (such as associated irq, or device-specific platform_data) | |
272 | * are provided using conventional syntax. | |
273 | */ | |
274 | #define I2C_BOARD_INFO(dev_type, dev_addr) \ | |
275 | .type = dev_type, .addr = (dev_addr) | |
276 | ||
277 | ||
278 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
279 | /* Add-on boards should register/unregister their devices; e.g. a board | |
280 | * with integrated I2C, a config eeprom, sensors, and a codec that's | |
281 | * used in conjunction with the primary hardware. | |
282 | */ | |
283 | extern struct i2c_client * | |
284 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); | |
285 | ||
286 | /* If you don't know the exact address of an I2C device, use this variant | |
287 | * instead, which can probe for device presence in a list of possible | |
288 | * addresses. The "probe" callback function is optional. If it is provided, | |
289 | * it must return 1 on successful probe, 0 otherwise. If it is not provided, | |
290 | * a default probing method is used. | |
291 | */ | |
292 | extern struct i2c_client * | |
293 | i2c_new_probed_device(struct i2c_adapter *adap, | |
294 | struct i2c_board_info *info, | |
295 | unsigned short const *addr_list, | |
296 | int (*probe)(struct i2c_adapter *, unsigned short addr)); | |
297 | ||
298 | /* Common custom probe functions */ | |
299 | extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); | |
300 | ||
301 | /* For devices that use several addresses, use i2c_new_dummy() to make | |
302 | * client handles for the extra addresses. | |
303 | */ | |
304 | extern struct i2c_client * | |
305 | i2c_new_dummy(struct i2c_adapter *adap, u16 address); | |
306 | ||
307 | extern void i2c_unregister_device(struct i2c_client *); | |
308 | #endif /* I2C */ | |
309 | ||
310 | /* Mainboard arch_initcall() code should register all its I2C devices. | |
311 | * This is done at arch_initcall time, before declaring any i2c adapters. | |
312 | * Modules for add-on boards must use other calls. | |
313 | */ | |
314 | #ifdef CONFIG_I2C_BOARDINFO | |
315 | extern int | |
316 | i2c_register_board_info(int busnum, struct i2c_board_info const *info, | |
317 | unsigned n); | |
318 | #else | |
319 | static inline int | |
320 | i2c_register_board_info(int busnum, struct i2c_board_info const *info, | |
321 | unsigned n) | |
322 | { | |
323 | return 0; | |
324 | } | |
325 | #endif /* I2C_BOARDINFO */ | |
326 | ||
327 | /* | |
328 | * The following structs are for those who like to implement new bus drivers: | |
329 | * i2c_algorithm is the interface to a class of hardware solutions which can | |
330 | * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 | |
331 | * to name two of the most common. | |
332 | */ | |
333 | struct i2c_algorithm { | |
334 | /* If an adapter algorithm can't do I2C-level access, set master_xfer | |
335 | to NULL. If an adapter algorithm can do SMBus access, set | |
336 | smbus_xfer. If set to NULL, the SMBus protocol is simulated | |
337 | using common I2C messages */ | |
338 | /* master_xfer should return the number of messages successfully | |
339 | processed, or a negative value on error */ | |
340 | int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
341 | int num); | |
342 | int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, | |
343 | unsigned short flags, char read_write, | |
344 | u8 command, int size, union i2c_smbus_data *data); | |
345 | ||
346 | /* To determine what the adapter supports */ | |
347 | u32 (*functionality) (struct i2c_adapter *); | |
348 | }; | |
349 | ||
350 | /* | |
351 | * i2c_adapter is the structure used to identify a physical i2c bus along | |
352 | * with the access algorithms necessary to access it. | |
353 | */ | |
354 | struct i2c_adapter { | |
355 | struct module *owner; | |
356 | unsigned int id; | |
357 | unsigned int class; /* classes to allow probing for */ | |
358 | const struct i2c_algorithm *algo; /* the algorithm to access the bus */ | |
359 | void *algo_data; | |
360 | ||
361 | /* data fields that are valid for all devices */ | |
362 | struct rt_mutex bus_lock; | |
363 | ||
364 | int timeout; /* in jiffies */ | |
365 | int retries; | |
366 | struct device dev; /* the adapter device */ | |
367 | ||
368 | int nr; | |
369 | char name[48]; | |
370 | struct completion dev_released; | |
371 | ||
372 | struct mutex userspace_clients_lock; | |
373 | struct list_head userspace_clients; | |
374 | }; | |
375 | #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) | |
376 | ||
377 | static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) | |
378 | { | |
379 | return dev_get_drvdata(&dev->dev); | |
380 | } | |
381 | ||
382 | static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) | |
383 | { | |
384 | dev_set_drvdata(&dev->dev, data); | |
385 | } | |
386 | ||
387 | static inline struct i2c_adapter * | |
388 | i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) | |
389 | { | |
390 | struct device *parent = adapter->dev.parent; | |
391 | ||
392 | if (parent != NULL && parent->type == &i2c_adapter_type) | |
393 | return to_i2c_adapter(parent); | |
394 | else | |
395 | return NULL; | |
396 | } | |
397 | ||
398 | /* Adapter locking functions, exported for shared pin cases */ | |
399 | void i2c_lock_adapter(struct i2c_adapter *); | |
400 | void i2c_unlock_adapter(struct i2c_adapter *); | |
401 | ||
402 | /*flags for the client struct: */ | |
403 | #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ | |
404 | #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ | |
405 | /* Must equal I2C_M_TEN below */ | |
406 | #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ | |
407 | ||
408 | /* i2c adapter classes (bitmask) */ | |
409 | #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ | |
410 | #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ | |
411 | #define I2C_CLASS_SPD (1<<7) /* SPD EEPROMs and similar */ | |
412 | ||
413 | /* Internal numbers to terminate lists */ | |
414 | #define I2C_CLIENT_END 0xfffeU | |
415 | ||
416 | /* The numbers to use to set I2C bus address */ | |
417 | #define ANY_I2C_BUS 0xffff | |
418 | ||
419 | /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ | |
420 | #define I2C_ADDRS(addr, addrs...) \ | |
421 | ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) | |
422 | ||
423 | ||
424 | /* ----- functions exported by i2c.o */ | |
425 | ||
426 | /* administration... | |
427 | */ | |
428 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
429 | extern int i2c_add_adapter(struct i2c_adapter *); | |
430 | extern int i2c_del_adapter(struct i2c_adapter *); | |
431 | extern int i2c_add_numbered_adapter(struct i2c_adapter *); | |
432 | ||
433 | extern int i2c_register_driver(struct module *, struct i2c_driver *); | |
434 | extern void i2c_del_driver(struct i2c_driver *); | |
435 | ||
436 | static inline int i2c_add_driver(struct i2c_driver *driver) | |
437 | { | |
438 | return i2c_register_driver(THIS_MODULE, driver); | |
439 | } | |
440 | ||
441 | extern struct i2c_client *i2c_use_client(struct i2c_client *client); | |
442 | extern void i2c_release_client(struct i2c_client *client); | |
443 | ||
444 | /* call the i2c_client->command() of all attached clients with | |
445 | * the given arguments */ | |
446 | extern void i2c_clients_command(struct i2c_adapter *adap, | |
447 | unsigned int cmd, void *arg); | |
448 | ||
449 | extern struct i2c_adapter *i2c_get_adapter(int id); | |
450 | extern void i2c_put_adapter(struct i2c_adapter *adap); | |
451 | ||
452 | ||
453 | /* Return the functionality mask */ | |
454 | static inline u32 i2c_get_functionality(struct i2c_adapter *adap) | |
455 | { | |
456 | return adap->algo->functionality(adap); | |
457 | } | |
458 | ||
459 | /* Return 1 if adapter supports everything we need, 0 if not. */ | |
460 | static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) | |
461 | { | |
462 | return (func & i2c_get_functionality(adap)) == func; | |
463 | } | |
464 | ||
465 | /* Return the adapter number for a specific adapter */ | |
466 | static inline int i2c_adapter_id(struct i2c_adapter *adap) | |
467 | { | |
468 | return adap->nr; | |
469 | } | |
470 | #endif /* I2C */ | |
471 | #endif /* __KERNEL__ */ | |
472 | ||
473 | /** | |
474 | * struct i2c_msg - an I2C transaction segment beginning with START | |
475 | * @addr: Slave address, either seven or ten bits. When this is a ten | |
476 | * bit address, I2C_M_TEN must be set in @flags and the adapter | |
477 | * must support I2C_FUNC_10BIT_ADDR. | |
478 | * @flags: I2C_M_RD is handled by all adapters. No other flags may be | |
479 | * provided unless the adapter exported the relevant I2C_FUNC_* | |
480 | * flags through i2c_check_functionality(). | |
481 | * @len: Number of data bytes in @buf being read from or written to the | |
482 | * I2C slave address. For read transactions where I2C_M_RECV_LEN | |
483 | * is set, the caller guarantees that this buffer can hold up to | |
484 | * 32 bytes in addition to the initial length byte sent by the | |
485 | * slave (plus, if used, the SMBus PEC); and this value will be | |
486 | * incremented by the number of block data bytes received. | |
487 | * @buf: The buffer into which data is read, or from which it's written. | |
488 | * | |
489 | * An i2c_msg is the low level representation of one segment of an I2C | |
490 | * transaction. It is visible to drivers in the @i2c_transfer() procedure, | |
491 | * to userspace from i2c-dev, and to I2C adapter drivers through the | |
492 | * @i2c_adapter.@master_xfer() method. | |
493 | * | |
494 | * Except when I2C "protocol mangling" is used, all I2C adapters implement | |
495 | * the standard rules for I2C transactions. Each transaction begins with a | |
496 | * START. That is followed by the slave address, and a bit encoding read | |
497 | * versus write. Then follow all the data bytes, possibly including a byte | |
498 | * with SMBus PEC. The transfer terminates with a NAK, or when all those | |
499 | * bytes have been transferred and ACKed. If this is the last message in a | |
500 | * group, it is followed by a STOP. Otherwise it is followed by the next | |
501 | * @i2c_msg transaction segment, beginning with a (repeated) START. | |
502 | * | |
503 | * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then | |
504 | * passing certain @flags may have changed those standard protocol behaviors. | |
505 | * Those flags are only for use with broken/nonconforming slaves, and with | |
506 | * adapters which are known to support the specific mangling options they | |
507 | * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR). | |
508 | */ | |
509 | struct i2c_msg { | |
510 | __u16 addr; /* slave address */ | |
511 | __u16 flags; | |
512 | #define I2C_M_TEN 0x0010 /* this is a ten bit chip address */ | |
513 | #define I2C_M_RD 0x0001 /* read data, from slave to master */ | |
514 | #define I2C_M_NOSTART 0x4000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
515 | #define I2C_M_REV_DIR_ADDR 0x2000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
516 | #define I2C_M_IGNORE_NAK 0x1000 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
517 | #define I2C_M_NO_RD_ACK 0x0800 /* if I2C_FUNC_PROTOCOL_MANGLING */ | |
518 | #define I2C_M_RECV_LEN 0x0400 /* length will be first received byte */ | |
519 | __u16 len; /* msg length */ | |
520 | __u8 *buf; /* pointer to msg data */ | |
521 | }; | |
522 | ||
523 | /* To determine what functionality is present */ | |
524 | ||
525 | #define I2C_FUNC_I2C 0x00000001 | |
526 | #define I2C_FUNC_10BIT_ADDR 0x00000002 | |
527 | #define I2C_FUNC_PROTOCOL_MANGLING 0x00000004 /* I2C_M_NOSTART etc. */ | |
528 | #define I2C_FUNC_SMBUS_PEC 0x00000008 | |
529 | #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL 0x00008000 /* SMBus 2.0 */ | |
530 | #define I2C_FUNC_SMBUS_QUICK 0x00010000 | |
531 | #define I2C_FUNC_SMBUS_READ_BYTE 0x00020000 | |
532 | #define I2C_FUNC_SMBUS_WRITE_BYTE 0x00040000 | |
533 | #define I2C_FUNC_SMBUS_READ_BYTE_DATA 0x00080000 | |
534 | #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA 0x00100000 | |
535 | #define I2C_FUNC_SMBUS_READ_WORD_DATA 0x00200000 | |
536 | #define I2C_FUNC_SMBUS_WRITE_WORD_DATA 0x00400000 | |
537 | #define I2C_FUNC_SMBUS_PROC_CALL 0x00800000 | |
538 | #define I2C_FUNC_SMBUS_READ_BLOCK_DATA 0x01000000 | |
539 | #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000 | |
540 | #define I2C_FUNC_SMBUS_READ_I2C_BLOCK 0x04000000 /* I2C-like block xfer */ | |
541 | #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK 0x08000000 /* w/ 1-byte reg. addr. */ | |
542 | ||
543 | #define I2C_FUNC_SMBUS_BYTE (I2C_FUNC_SMBUS_READ_BYTE | \ | |
544 | I2C_FUNC_SMBUS_WRITE_BYTE) | |
545 | #define I2C_FUNC_SMBUS_BYTE_DATA (I2C_FUNC_SMBUS_READ_BYTE_DATA | \ | |
546 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA) | |
547 | #define I2C_FUNC_SMBUS_WORD_DATA (I2C_FUNC_SMBUS_READ_WORD_DATA | \ | |
548 | I2C_FUNC_SMBUS_WRITE_WORD_DATA) | |
549 | #define I2C_FUNC_SMBUS_BLOCK_DATA (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \ | |
550 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA) | |
551 | #define I2C_FUNC_SMBUS_I2C_BLOCK (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \ | |
552 | I2C_FUNC_SMBUS_WRITE_I2C_BLOCK) | |
553 | ||
554 | #define I2C_FUNC_SMBUS_EMUL (I2C_FUNC_SMBUS_QUICK | \ | |
555 | I2C_FUNC_SMBUS_BYTE | \ | |
556 | I2C_FUNC_SMBUS_BYTE_DATA | \ | |
557 | I2C_FUNC_SMBUS_WORD_DATA | \ | |
558 | I2C_FUNC_SMBUS_PROC_CALL | \ | |
559 | I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \ | |
560 | I2C_FUNC_SMBUS_I2C_BLOCK | \ | |
561 | I2C_FUNC_SMBUS_PEC) | |
562 | ||
563 | /* | |
564 | * Data for SMBus Messages | |
565 | */ | |
566 | #define I2C_SMBUS_BLOCK_MAX 32 /* As specified in SMBus standard */ | |
567 | union i2c_smbus_data { | |
568 | __u8 byte; | |
569 | __u16 word; | |
570 | __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */ | |
571 | /* and one more for user-space compatibility */ | |
572 | }; | |
573 | ||
574 | /* i2c_smbus_xfer read or write markers */ | |
575 | #define I2C_SMBUS_READ 1 | |
576 | #define I2C_SMBUS_WRITE 0 | |
577 | ||
578 | /* SMBus transaction types (size parameter in the above functions) | |
579 | Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */ | |
580 | #define I2C_SMBUS_QUICK 0 | |
581 | #define I2C_SMBUS_BYTE 1 | |
582 | #define I2C_SMBUS_BYTE_DATA 2 | |
583 | #define I2C_SMBUS_WORD_DATA 3 | |
584 | #define I2C_SMBUS_PROC_CALL 4 | |
585 | #define I2C_SMBUS_BLOCK_DATA 5 | |
586 | #define I2C_SMBUS_I2C_BLOCK_BROKEN 6 | |
587 | #define I2C_SMBUS_BLOCK_PROC_CALL 7 /* SMBus 2.0 */ | |
588 | #define I2C_SMBUS_I2C_BLOCK_DATA 8 | |
589 | ||
590 | #endif /* _LINUX_I2C_H */ |