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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., 51 Franklin Street, Fifth Floor, Boston, | |
21 | MA 02110-1301 USA. */ | |
22 | /* ------------------------------------------------------------------------- */ | |
23 | ||
24 | /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and | |
25 | Frodo Looijaard <frodol@dds.nl> */ | |
26 | #ifndef _LINUX_I2C_H | |
27 | #define _LINUX_I2C_H | |
28 | ||
29 | #include <linux/mod_devicetable.h> | |
30 | #include <linux/device.h> /* for struct device */ | |
31 | #include <linux/sched.h> /* for completion */ | |
32 | #include <linux/mutex.h> | |
33 | #include <linux/rtmutex.h> | |
34 | #include <linux/irqdomain.h> /* for Host Notify IRQ */ | |
35 | #include <linux/of.h> /* for struct device_node */ | |
36 | #include <linux/swab.h> /* for swab16 */ | |
37 | #include <uapi/linux/i2c.h> | |
38 | ||
39 | extern struct bus_type i2c_bus_type; | |
40 | extern struct device_type i2c_adapter_type; | |
41 | extern struct device_type i2c_client_type; | |
42 | ||
43 | /* --- General options ------------------------------------------------ */ | |
44 | ||
45 | struct i2c_msg; | |
46 | struct i2c_algorithm; | |
47 | struct i2c_adapter; | |
48 | struct i2c_client; | |
49 | struct i2c_driver; | |
50 | union i2c_smbus_data; | |
51 | struct i2c_board_info; | |
52 | enum i2c_slave_event; | |
53 | typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); | |
54 | ||
55 | struct module; | |
56 | struct property_entry; | |
57 | ||
58 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
59 | /* | |
60 | * The master routines are the ones normally used to transmit data to devices | |
61 | * on a bus (or read from them). Apart from two basic transfer functions to | |
62 | * transmit one message at a time, a more complex version can be used to | |
63 | * transmit an arbitrary number of messages without interruption. | |
64 | * @count must be be less than 64k since msg.len is u16. | |
65 | */ | |
66 | extern int i2c_master_send(const struct i2c_client *client, const char *buf, | |
67 | int count); | |
68 | extern int i2c_master_recv(const struct i2c_client *client, char *buf, | |
69 | int count); | |
70 | ||
71 | /* Transfer num messages. | |
72 | */ | |
73 | extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
74 | int num); | |
75 | /* Unlocked flavor */ | |
76 | extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
77 | int num); | |
78 | ||
79 | /* This is the very generalized SMBus access routine. You probably do not | |
80 | want to use this, though; one of the functions below may be much easier, | |
81 | and probably just as fast. | |
82 | Note that we use i2c_adapter here, because you do not need a specific | |
83 | smbus adapter to call this function. */ | |
84 | extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, | |
85 | unsigned short flags, char read_write, u8 command, | |
86 | int size, union i2c_smbus_data *data); | |
87 | ||
88 | /* Now follow the 'nice' access routines. These also document the calling | |
89 | conventions of i2c_smbus_xfer. */ | |
90 | ||
91 | extern s32 i2c_smbus_read_byte(const struct i2c_client *client); | |
92 | extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); | |
93 | extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, | |
94 | u8 command); | |
95 | extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, | |
96 | u8 command, u8 value); | |
97 | extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, | |
98 | u8 command); | |
99 | extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, | |
100 | u8 command, u16 value); | |
101 | ||
102 | static inline s32 | |
103 | i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) | |
104 | { | |
105 | s32 value = i2c_smbus_read_word_data(client, command); | |
106 | ||
107 | return (value < 0) ? value : swab16(value); | |
108 | } | |
109 | ||
110 | static inline s32 | |
111 | i2c_smbus_write_word_swapped(const struct i2c_client *client, | |
112 | u8 command, u16 value) | |
113 | { | |
114 | return i2c_smbus_write_word_data(client, command, swab16(value)); | |
115 | } | |
116 | ||
117 | /* Returns the number of read bytes */ | |
118 | extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, | |
119 | u8 command, u8 *values); | |
120 | extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, | |
121 | u8 command, u8 length, const u8 *values); | |
122 | /* Returns the number of read bytes */ | |
123 | extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, | |
124 | u8 command, u8 length, u8 *values); | |
125 | extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, | |
126 | u8 command, u8 length, | |
127 | const u8 *values); | |
128 | extern s32 | |
129 | i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, | |
130 | u8 command, u8 length, u8 *values); | |
131 | #endif /* I2C */ | |
132 | ||
133 | enum i2c_alert_protocol { | |
134 | I2C_PROTOCOL_SMBUS_ALERT, | |
135 | I2C_PROTOCOL_SMBUS_HOST_NOTIFY, | |
136 | }; | |
137 | ||
138 | /** | |
139 | * struct i2c_driver - represent an I2C device driver | |
140 | * @class: What kind of i2c device we instantiate (for detect) | |
141 | * @attach_adapter: Callback for bus addition (deprecated) | |
142 | * @probe: Callback for device binding - soon to be deprecated | |
143 | * @probe_new: New callback for device binding | |
144 | * @remove: Callback for device unbinding | |
145 | * @shutdown: Callback for device shutdown | |
146 | * @alert: Alert callback, for example for the SMBus alert protocol | |
147 | * @command: Callback for bus-wide signaling (optional) | |
148 | * @driver: Device driver model driver | |
149 | * @id_table: List of I2C devices supported by this driver | |
150 | * @detect: Callback for device detection | |
151 | * @address_list: The I2C addresses to probe (for detect) | |
152 | * @clients: List of detected clients we created (for i2c-core use only) | |
153 | * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping | |
154 | * | |
155 | * The driver.owner field should be set to the module owner of this driver. | |
156 | * The driver.name field should be set to the name of this driver. | |
157 | * | |
158 | * For automatic device detection, both @detect and @address_list must | |
159 | * be defined. @class should also be set, otherwise only devices forced | |
160 | * with module parameters will be created. The detect function must | |
161 | * fill at least the name field of the i2c_board_info structure it is | |
162 | * handed upon successful detection, and possibly also the flags field. | |
163 | * | |
164 | * If @detect is missing, the driver will still work fine for enumerated | |
165 | * devices. Detected devices simply won't be supported. This is expected | |
166 | * for the many I2C/SMBus devices which can't be detected reliably, and | |
167 | * the ones which can always be enumerated in practice. | |
168 | * | |
169 | * The i2c_client structure which is handed to the @detect callback is | |
170 | * not a real i2c_client. It is initialized just enough so that you can | |
171 | * call i2c_smbus_read_byte_data and friends on it. Don't do anything | |
172 | * else with it. In particular, calling dev_dbg and friends on it is | |
173 | * not allowed. | |
174 | */ | |
175 | struct i2c_driver { | |
176 | unsigned int class; | |
177 | ||
178 | /* Notifies the driver that a new bus has appeared. You should avoid | |
179 | * using this, it will be removed in a near future. | |
180 | */ | |
181 | int (*attach_adapter)(struct i2c_adapter *) __deprecated; | |
182 | ||
183 | /* Standard driver model interfaces */ | |
184 | int (*probe)(struct i2c_client *, const struct i2c_device_id *); | |
185 | int (*remove)(struct i2c_client *); | |
186 | ||
187 | /* New driver model interface to aid the seamless removal of the | |
188 | * current probe()'s, more commonly unused than used second parameter. | |
189 | */ | |
190 | int (*probe_new)(struct i2c_client *); | |
191 | ||
192 | /* driver model interfaces that don't relate to enumeration */ | |
193 | void (*shutdown)(struct i2c_client *); | |
194 | ||
195 | /* Alert callback, for example for the SMBus alert protocol. | |
196 | * The format and meaning of the data value depends on the protocol. | |
197 | * For the SMBus alert protocol, there is a single bit of data passed | |
198 | * as the alert response's low bit ("event flag"). | |
199 | * For the SMBus Host Notify protocol, the data corresponds to the | |
200 | * 16-bit payload data reported by the slave device acting as master. | |
201 | */ | |
202 | void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, | |
203 | unsigned int data); | |
204 | ||
205 | /* a ioctl like command that can be used to perform specific functions | |
206 | * with the device. | |
207 | */ | |
208 | int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); | |
209 | ||
210 | struct device_driver driver; | |
211 | const struct i2c_device_id *id_table; | |
212 | ||
213 | /* Device detection callback for automatic device creation */ | |
214 | int (*detect)(struct i2c_client *, struct i2c_board_info *); | |
215 | const unsigned short *address_list; | |
216 | struct list_head clients; | |
217 | ||
218 | bool disable_i2c_core_irq_mapping; | |
219 | }; | |
220 | #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) | |
221 | ||
222 | /** | |
223 | * struct i2c_client - represent an I2C slave device | |
224 | * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; | |
225 | * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking | |
226 | * @addr: Address used on the I2C bus connected to the parent adapter. | |
227 | * @name: Indicates the type of the device, usually a chip name that's | |
228 | * generic enough to hide second-sourcing and compatible revisions. | |
229 | * @adapter: manages the bus segment hosting this I2C device | |
230 | * @dev: Driver model device node for the slave. | |
231 | * @irq: indicates the IRQ generated by this device (if any) | |
232 | * @detected: member of an i2c_driver.clients list or i2c-core's | |
233 | * userspace_devices list | |
234 | * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter | |
235 | * calls it to pass on slave events to the slave driver. | |
236 | * | |
237 | * An i2c_client identifies a single device (i.e. chip) connected to an | |
238 | * i2c bus. The behaviour exposed to Linux is defined by the driver | |
239 | * managing the device. | |
240 | */ | |
241 | struct i2c_client { | |
242 | unsigned short flags; /* div., see below */ | |
243 | unsigned short addr; /* chip address - NOTE: 7bit */ | |
244 | /* addresses are stored in the */ | |
245 | /* _LOWER_ 7 bits */ | |
246 | char name[I2C_NAME_SIZE]; | |
247 | struct i2c_adapter *adapter; /* the adapter we sit on */ | |
248 | struct device dev; /* the device structure */ | |
249 | int irq; /* irq issued by device */ | |
250 | struct list_head detected; | |
251 | #if IS_ENABLED(CONFIG_I2C_SLAVE) | |
252 | i2c_slave_cb_t slave_cb; /* callback for slave mode */ | |
253 | #endif | |
254 | }; | |
255 | #define to_i2c_client(d) container_of(d, struct i2c_client, dev) | |
256 | ||
257 | extern struct i2c_client *i2c_verify_client(struct device *dev); | |
258 | extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); | |
259 | extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, | |
260 | const struct i2c_client *client); | |
261 | ||
262 | static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) | |
263 | { | |
264 | struct device * const dev = container_of(kobj, struct device, kobj); | |
265 | return to_i2c_client(dev); | |
266 | } | |
267 | ||
268 | static inline void *i2c_get_clientdata(const struct i2c_client *dev) | |
269 | { | |
270 | return dev_get_drvdata(&dev->dev); | |
271 | } | |
272 | ||
273 | static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) | |
274 | { | |
275 | dev_set_drvdata(&dev->dev, data); | |
276 | } | |
277 | ||
278 | /* I2C slave support */ | |
279 | ||
280 | #if IS_ENABLED(CONFIG_I2C_SLAVE) | |
281 | enum i2c_slave_event { | |
282 | I2C_SLAVE_READ_REQUESTED, | |
283 | I2C_SLAVE_WRITE_REQUESTED, | |
284 | I2C_SLAVE_READ_PROCESSED, | |
285 | I2C_SLAVE_WRITE_RECEIVED, | |
286 | I2C_SLAVE_STOP, | |
287 | }; | |
288 | ||
289 | extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); | |
290 | extern int i2c_slave_unregister(struct i2c_client *client); | |
291 | extern bool i2c_detect_slave_mode(struct device *dev); | |
292 | ||
293 | static inline int i2c_slave_event(struct i2c_client *client, | |
294 | enum i2c_slave_event event, u8 *val) | |
295 | { | |
296 | return client->slave_cb(client, event, val); | |
297 | } | |
298 | #else | |
299 | static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } | |
300 | #endif | |
301 | ||
302 | /** | |
303 | * struct i2c_board_info - template for device creation | |
304 | * @type: chip type, to initialize i2c_client.name | |
305 | * @flags: to initialize i2c_client.flags | |
306 | * @addr: stored in i2c_client.addr | |
307 | * @platform_data: stored in i2c_client.dev.platform_data | |
308 | * @archdata: copied into i2c_client.dev.archdata | |
309 | * @of_node: pointer to OpenFirmware device node | |
310 | * @fwnode: device node supplied by the platform firmware | |
311 | * @properties: additional device properties for the device | |
312 | * @resources: resources associated with the device | |
313 | * @num_resources: number of resources in the @resources array | |
314 | * @irq: stored in i2c_client.irq | |
315 | * | |
316 | * I2C doesn't actually support hardware probing, although controllers and | |
317 | * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's | |
318 | * a device at a given address. Drivers commonly need more information than | |
319 | * that, such as chip type, configuration, associated IRQ, and so on. | |
320 | * | |
321 | * i2c_board_info is used to build tables of information listing I2C devices | |
322 | * that are present. This information is used to grow the driver model tree. | |
323 | * For mainboards this is done statically using i2c_register_board_info(); | |
324 | * bus numbers identify adapters that aren't yet available. For add-on boards, | |
325 | * i2c_new_device() does this dynamically with the adapter already known. | |
326 | */ | |
327 | struct i2c_board_info { | |
328 | char type[I2C_NAME_SIZE]; | |
329 | unsigned short flags; | |
330 | unsigned short addr; | |
331 | void *platform_data; | |
332 | struct dev_archdata *archdata; | |
333 | struct device_node *of_node; | |
334 | struct fwnode_handle *fwnode; | |
335 | const struct property_entry *properties; | |
336 | const struct resource *resources; | |
337 | unsigned int num_resources; | |
338 | int irq; | |
339 | }; | |
340 | ||
341 | /** | |
342 | * I2C_BOARD_INFO - macro used to list an i2c device and its address | |
343 | * @dev_type: identifies the device type | |
344 | * @dev_addr: the device's address on the bus. | |
345 | * | |
346 | * This macro initializes essential fields of a struct i2c_board_info, | |
347 | * declaring what has been provided on a particular board. Optional | |
348 | * fields (such as associated irq, or device-specific platform_data) | |
349 | * are provided using conventional syntax. | |
350 | */ | |
351 | #define I2C_BOARD_INFO(dev_type, dev_addr) \ | |
352 | .type = dev_type, .addr = (dev_addr) | |
353 | ||
354 | ||
355 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
356 | /* Add-on boards should register/unregister their devices; e.g. a board | |
357 | * with integrated I2C, a config eeprom, sensors, and a codec that's | |
358 | * used in conjunction with the primary hardware. | |
359 | */ | |
360 | extern struct i2c_client * | |
361 | i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); | |
362 | ||
363 | /* If you don't know the exact address of an I2C device, use this variant | |
364 | * instead, which can probe for device presence in a list of possible | |
365 | * addresses. The "probe" callback function is optional. If it is provided, | |
366 | * it must return 1 on successful probe, 0 otherwise. If it is not provided, | |
367 | * a default probing method is used. | |
368 | */ | |
369 | extern struct i2c_client * | |
370 | i2c_new_probed_device(struct i2c_adapter *adap, | |
371 | struct i2c_board_info *info, | |
372 | unsigned short const *addr_list, | |
373 | int (*probe)(struct i2c_adapter *, unsigned short addr)); | |
374 | ||
375 | /* Common custom probe functions */ | |
376 | extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); | |
377 | ||
378 | /* For devices that use several addresses, use i2c_new_dummy() to make | |
379 | * client handles for the extra addresses. | |
380 | */ | |
381 | extern struct i2c_client * | |
382 | i2c_new_dummy(struct i2c_adapter *adap, u16 address); | |
383 | ||
384 | extern struct i2c_client * | |
385 | i2c_new_secondary_device(struct i2c_client *client, | |
386 | const char *name, | |
387 | u16 default_addr); | |
388 | ||
389 | extern void i2c_unregister_device(struct i2c_client *); | |
390 | #endif /* I2C */ | |
391 | ||
392 | /* Mainboard arch_initcall() code should register all its I2C devices. | |
393 | * This is done at arch_initcall time, before declaring any i2c adapters. | |
394 | * Modules for add-on boards must use other calls. | |
395 | */ | |
396 | #ifdef CONFIG_I2C_BOARDINFO | |
397 | extern int | |
398 | i2c_register_board_info(int busnum, struct i2c_board_info const *info, | |
399 | unsigned n); | |
400 | #else | |
401 | static inline int | |
402 | i2c_register_board_info(int busnum, struct i2c_board_info const *info, | |
403 | unsigned n) | |
404 | { | |
405 | return 0; | |
406 | } | |
407 | #endif /* I2C_BOARDINFO */ | |
408 | ||
409 | /** | |
410 | * struct i2c_algorithm - represent I2C transfer method | |
411 | * @master_xfer: Issue a set of i2c transactions to the given I2C adapter | |
412 | * defined by the msgs array, with num messages available to transfer via | |
413 | * the adapter specified by adap. | |
414 | * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this | |
415 | * is not present, then the bus layer will try and convert the SMBus calls | |
416 | * into I2C transfers instead. | |
417 | * @functionality: Return the flags that this algorithm/adapter pair supports | |
418 | * from the I2C_FUNC_* flags. | |
419 | * @reg_slave: Register given client to I2C slave mode of this adapter | |
420 | * @unreg_slave: Unregister given client from I2C slave mode of this adapter | |
421 | * | |
422 | * The following structs are for those who like to implement new bus drivers: | |
423 | * i2c_algorithm is the interface to a class of hardware solutions which can | |
424 | * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 | |
425 | * to name two of the most common. | |
426 | * | |
427 | * The return codes from the @master_xfer field should indicate the type of | |
428 | * error code that occurred during the transfer, as documented in the kernel | |
429 | * Documentation file Documentation/i2c/fault-codes. | |
430 | */ | |
431 | struct i2c_algorithm { | |
432 | /* If an adapter algorithm can't do I2C-level access, set master_xfer | |
433 | to NULL. If an adapter algorithm can do SMBus access, set | |
434 | smbus_xfer. If set to NULL, the SMBus protocol is simulated | |
435 | using common I2C messages */ | |
436 | /* master_xfer should return the number of messages successfully | |
437 | processed, or a negative value on error */ | |
438 | int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, | |
439 | int num); | |
440 | int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, | |
441 | unsigned short flags, char read_write, | |
442 | u8 command, int size, union i2c_smbus_data *data); | |
443 | ||
444 | /* To determine what the adapter supports */ | |
445 | u32 (*functionality) (struct i2c_adapter *); | |
446 | ||
447 | #if IS_ENABLED(CONFIG_I2C_SLAVE) | |
448 | int (*reg_slave)(struct i2c_client *client); | |
449 | int (*unreg_slave)(struct i2c_client *client); | |
450 | #endif | |
451 | }; | |
452 | ||
453 | /** | |
454 | * struct i2c_lock_operations - represent I2C locking operations | |
455 | * @lock_bus: Get exclusive access to an I2C bus segment | |
456 | * @trylock_bus: Try to get exclusive access to an I2C bus segment | |
457 | * @unlock_bus: Release exclusive access to an I2C bus segment | |
458 | * | |
459 | * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. | |
460 | */ | |
461 | struct i2c_lock_operations { | |
462 | void (*lock_bus)(struct i2c_adapter *, unsigned int flags); | |
463 | int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); | |
464 | void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); | |
465 | }; | |
466 | ||
467 | /** | |
468 | * struct i2c_timings - I2C timing information | |
469 | * @bus_freq_hz: the bus frequency in Hz | |
470 | * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification | |
471 | * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification | |
472 | * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns | |
473 | * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification | |
474 | */ | |
475 | struct i2c_timings { | |
476 | u32 bus_freq_hz; | |
477 | u32 scl_rise_ns; | |
478 | u32 scl_fall_ns; | |
479 | u32 scl_int_delay_ns; | |
480 | u32 sda_fall_ns; | |
481 | }; | |
482 | ||
483 | /** | |
484 | * struct i2c_bus_recovery_info - I2C bus recovery information | |
485 | * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or | |
486 | * i2c_generic_scl_recovery() or i2c_generic_gpio_recovery(). | |
487 | * @get_scl: This gets current value of SCL line. Mandatory for generic SCL | |
488 | * recovery. Used internally for generic GPIO recovery. | |
489 | * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used | |
490 | * internally for generic GPIO recovery. | |
491 | * @get_sda: This gets current value of SDA line. Optional for generic SCL | |
492 | * recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO | |
493 | * recovery. | |
494 | * @prepare_recovery: This will be called before starting recovery. Platform may | |
495 | * configure padmux here for SDA/SCL line or something else they want. | |
496 | * @unprepare_recovery: This will be called after completing recovery. Platform | |
497 | * may configure padmux here for SDA/SCL line or something else they want. | |
498 | * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery. | |
499 | * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery. | |
500 | */ | |
501 | struct i2c_bus_recovery_info { | |
502 | int (*recover_bus)(struct i2c_adapter *); | |
503 | ||
504 | int (*get_scl)(struct i2c_adapter *); | |
505 | void (*set_scl)(struct i2c_adapter *, int val); | |
506 | int (*get_sda)(struct i2c_adapter *); | |
507 | ||
508 | void (*prepare_recovery)(struct i2c_adapter *); | |
509 | void (*unprepare_recovery)(struct i2c_adapter *); | |
510 | ||
511 | /* gpio recovery */ | |
512 | int scl_gpio; | |
513 | int sda_gpio; | |
514 | }; | |
515 | ||
516 | int i2c_recover_bus(struct i2c_adapter *adap); | |
517 | ||
518 | /* Generic recovery routines */ | |
519 | int i2c_generic_gpio_recovery(struct i2c_adapter *adap); | |
520 | int i2c_generic_scl_recovery(struct i2c_adapter *adap); | |
521 | ||
522 | /** | |
523 | * struct i2c_adapter_quirks - describe flaws of an i2c adapter | |
524 | * @flags: see I2C_AQ_* for possible flags and read below | |
525 | * @max_num_msgs: maximum number of messages per transfer | |
526 | * @max_write_len: maximum length of a write message | |
527 | * @max_read_len: maximum length of a read message | |
528 | * @max_comb_1st_msg_len: maximum length of the first msg in a combined message | |
529 | * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message | |
530 | * | |
531 | * Note about combined messages: Some I2C controllers can only send one message | |
532 | * per transfer, plus something called combined message or write-then-read. | |
533 | * This is (usually) a small write message followed by a read message and | |
534 | * barely enough to access register based devices like EEPROMs. There is a flag | |
535 | * to support this mode. It implies max_num_msg = 2 and does the length checks | |
536 | * with max_comb_*_len because combined message mode usually has its own | |
537 | * limitations. Because of HW implementations, some controllers can actually do | |
538 | * write-then-anything or other variants. To support that, write-then-read has | |
539 | * been broken out into smaller bits like write-first and read-second which can | |
540 | * be combined as needed. | |
541 | */ | |
542 | ||
543 | struct i2c_adapter_quirks { | |
544 | u64 flags; | |
545 | int max_num_msgs; | |
546 | u16 max_write_len; | |
547 | u16 max_read_len; | |
548 | u16 max_comb_1st_msg_len; | |
549 | u16 max_comb_2nd_msg_len; | |
550 | }; | |
551 | ||
552 | /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ | |
553 | #define I2C_AQ_COMB BIT(0) | |
554 | /* first combined message must be write */ | |
555 | #define I2C_AQ_COMB_WRITE_FIRST BIT(1) | |
556 | /* second combined message must be read */ | |
557 | #define I2C_AQ_COMB_READ_SECOND BIT(2) | |
558 | /* both combined messages must have the same target address */ | |
559 | #define I2C_AQ_COMB_SAME_ADDR BIT(3) | |
560 | /* convenience macro for typical write-then read case */ | |
561 | #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ | |
562 | I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) | |
563 | /* clock stretching is not supported */ | |
564 | #define I2C_AQ_NO_CLK_STRETCH BIT(4) | |
565 | ||
566 | /* | |
567 | * i2c_adapter is the structure used to identify a physical i2c bus along | |
568 | * with the access algorithms necessary to access it. | |
569 | */ | |
570 | struct i2c_adapter { | |
571 | struct module *owner; | |
572 | unsigned int class; /* classes to allow probing for */ | |
573 | const struct i2c_algorithm *algo; /* the algorithm to access the bus */ | |
574 | void *algo_data; | |
575 | ||
576 | /* data fields that are valid for all devices */ | |
577 | const struct i2c_lock_operations *lock_ops; | |
578 | struct rt_mutex bus_lock; | |
579 | struct rt_mutex mux_lock; | |
580 | ||
581 | int timeout; /* in jiffies */ | |
582 | int retries; | |
583 | struct device dev; /* the adapter device */ | |
584 | ||
585 | int nr; | |
586 | char name[48]; | |
587 | struct completion dev_released; | |
588 | ||
589 | struct mutex userspace_clients_lock; | |
590 | struct list_head userspace_clients; | |
591 | ||
592 | struct i2c_bus_recovery_info *bus_recovery_info; | |
593 | const struct i2c_adapter_quirks *quirks; | |
594 | ||
595 | struct irq_domain *host_notify_domain; | |
596 | }; | |
597 | #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) | |
598 | ||
599 | static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) | |
600 | { | |
601 | return dev_get_drvdata(&dev->dev); | |
602 | } | |
603 | ||
604 | static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) | |
605 | { | |
606 | dev_set_drvdata(&dev->dev, data); | |
607 | } | |
608 | ||
609 | static inline struct i2c_adapter * | |
610 | i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) | |
611 | { | |
612 | #if IS_ENABLED(CONFIG_I2C_MUX) | |
613 | struct device *parent = adapter->dev.parent; | |
614 | ||
615 | if (parent != NULL && parent->type == &i2c_adapter_type) | |
616 | return to_i2c_adapter(parent); | |
617 | else | |
618 | #endif | |
619 | return NULL; | |
620 | } | |
621 | ||
622 | int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); | |
623 | ||
624 | /* Adapter locking functions, exported for shared pin cases */ | |
625 | #define I2C_LOCK_ROOT_ADAPTER BIT(0) | |
626 | #define I2C_LOCK_SEGMENT BIT(1) | |
627 | ||
628 | /** | |
629 | * i2c_lock_bus - Get exclusive access to an I2C bus segment | |
630 | * @adapter: Target I2C bus segment | |
631 | * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT | |
632 | * locks only this branch in the adapter tree | |
633 | */ | |
634 | static inline void | |
635 | i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) | |
636 | { | |
637 | adapter->lock_ops->lock_bus(adapter, flags); | |
638 | } | |
639 | ||
640 | /** | |
641 | * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment | |
642 | * @adapter: Target I2C bus segment | |
643 | * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, | |
644 | * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree | |
645 | * | |
646 | * Return: true if the I2C bus segment is locked, false otherwise | |
647 | */ | |
648 | static inline int | |
649 | i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) | |
650 | { | |
651 | return adapter->lock_ops->trylock_bus(adapter, flags); | |
652 | } | |
653 | ||
654 | /** | |
655 | * i2c_unlock_bus - Release exclusive access to an I2C bus segment | |
656 | * @adapter: Target I2C bus segment | |
657 | * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT | |
658 | * unlocks only this branch in the adapter tree | |
659 | */ | |
660 | static inline void | |
661 | i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) | |
662 | { | |
663 | adapter->lock_ops->unlock_bus(adapter, flags); | |
664 | } | |
665 | ||
666 | static inline void | |
667 | i2c_lock_adapter(struct i2c_adapter *adapter) | |
668 | { | |
669 | i2c_lock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); | |
670 | } | |
671 | ||
672 | static inline void | |
673 | i2c_unlock_adapter(struct i2c_adapter *adapter) | |
674 | { | |
675 | i2c_unlock_bus(adapter, I2C_LOCK_ROOT_ADAPTER); | |
676 | } | |
677 | ||
678 | /*flags for the client struct: */ | |
679 | #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ | |
680 | #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ | |
681 | /* Must equal I2C_M_TEN below */ | |
682 | #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ | |
683 | #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ | |
684 | #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ | |
685 | #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ | |
686 | /* Must match I2C_M_STOP|IGNORE_NAK */ | |
687 | ||
688 | /* i2c adapter classes (bitmask) */ | |
689 | #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ | |
690 | #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ | |
691 | #define I2C_CLASS_SPD (1<<7) /* Memory modules */ | |
692 | /* Warn users that the adapter doesn't support classes anymore */ | |
693 | #define I2C_CLASS_DEPRECATED (1<<8) | |
694 | ||
695 | /* Internal numbers to terminate lists */ | |
696 | #define I2C_CLIENT_END 0xfffeU | |
697 | ||
698 | /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ | |
699 | #define I2C_ADDRS(addr, addrs...) \ | |
700 | ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) | |
701 | ||
702 | ||
703 | /* ----- functions exported by i2c.o */ | |
704 | ||
705 | /* administration... | |
706 | */ | |
707 | #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE) | |
708 | extern int i2c_add_adapter(struct i2c_adapter *); | |
709 | extern void i2c_del_adapter(struct i2c_adapter *); | |
710 | extern int i2c_add_numbered_adapter(struct i2c_adapter *); | |
711 | ||
712 | extern int i2c_register_driver(struct module *, struct i2c_driver *); | |
713 | extern void i2c_del_driver(struct i2c_driver *); | |
714 | ||
715 | /* use a define to avoid include chaining to get THIS_MODULE */ | |
716 | #define i2c_add_driver(driver) \ | |
717 | i2c_register_driver(THIS_MODULE, driver) | |
718 | ||
719 | extern struct i2c_client *i2c_use_client(struct i2c_client *client); | |
720 | extern void i2c_release_client(struct i2c_client *client); | |
721 | ||
722 | /* call the i2c_client->command() of all attached clients with | |
723 | * the given arguments */ | |
724 | extern void i2c_clients_command(struct i2c_adapter *adap, | |
725 | unsigned int cmd, void *arg); | |
726 | ||
727 | extern struct i2c_adapter *i2c_get_adapter(int nr); | |
728 | extern void i2c_put_adapter(struct i2c_adapter *adap); | |
729 | extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); | |
730 | ||
731 | void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); | |
732 | ||
733 | /* Return the functionality mask */ | |
734 | static inline u32 i2c_get_functionality(struct i2c_adapter *adap) | |
735 | { | |
736 | return adap->algo->functionality(adap); | |
737 | } | |
738 | ||
739 | /* Return 1 if adapter supports everything we need, 0 if not. */ | |
740 | static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) | |
741 | { | |
742 | return (func & i2c_get_functionality(adap)) == func; | |
743 | } | |
744 | ||
745 | /** | |
746 | * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter | |
747 | * @adap: i2c adapter | |
748 | * @quirks: quirk flags | |
749 | * | |
750 | * Return: true if the adapter has all the specified quirk flags, false if not | |
751 | */ | |
752 | static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) | |
753 | { | |
754 | if (!adap->quirks) | |
755 | return false; | |
756 | return (adap->quirks->flags & quirks) == quirks; | |
757 | } | |
758 | ||
759 | /* Return the adapter number for a specific adapter */ | |
760 | static inline int i2c_adapter_id(struct i2c_adapter *adap) | |
761 | { | |
762 | return adap->nr; | |
763 | } | |
764 | ||
765 | static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) | |
766 | { | |
767 | return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); | |
768 | } | |
769 | ||
770 | int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); | |
771 | /** | |
772 | * module_i2c_driver() - Helper macro for registering a modular I2C driver | |
773 | * @__i2c_driver: i2c_driver struct | |
774 | * | |
775 | * Helper macro for I2C drivers which do not do anything special in module | |
776 | * init/exit. This eliminates a lot of boilerplate. Each module may only | |
777 | * use this macro once, and calling it replaces module_init() and module_exit() | |
778 | */ | |
779 | #define module_i2c_driver(__i2c_driver) \ | |
780 | module_driver(__i2c_driver, i2c_add_driver, \ | |
781 | i2c_del_driver) | |
782 | ||
783 | /** | |
784 | * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver | |
785 | * @__i2c_driver: i2c_driver struct | |
786 | * | |
787 | * Helper macro for I2C drivers which do not do anything special in their | |
788 | * init. This eliminates a lot of boilerplate. Each driver may only | |
789 | * use this macro once, and calling it replaces device_initcall(). | |
790 | */ | |
791 | #define builtin_i2c_driver(__i2c_driver) \ | |
792 | builtin_driver(__i2c_driver, i2c_add_driver) | |
793 | ||
794 | #endif /* I2C */ | |
795 | ||
796 | #if IS_ENABLED(CONFIG_OF) | |
797 | /* must call put_device() when done with returned i2c_client device */ | |
798 | extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); | |
799 | ||
800 | /* must call put_device() when done with returned i2c_adapter device */ | |
801 | extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); | |
802 | ||
803 | /* must call i2c_put_adapter() when done with returned i2c_adapter device */ | |
804 | struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); | |
805 | ||
806 | extern const struct of_device_id | |
807 | *i2c_of_match_device(const struct of_device_id *matches, | |
808 | struct i2c_client *client); | |
809 | ||
810 | #else | |
811 | ||
812 | static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) | |
813 | { | |
814 | return NULL; | |
815 | } | |
816 | ||
817 | static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) | |
818 | { | |
819 | return NULL; | |
820 | } | |
821 | ||
822 | static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) | |
823 | { | |
824 | return NULL; | |
825 | } | |
826 | ||
827 | static inline const struct of_device_id | |
828 | *i2c_of_match_device(const struct of_device_id *matches, | |
829 | struct i2c_client *client) | |
830 | { | |
831 | return NULL; | |
832 | } | |
833 | ||
834 | #endif /* CONFIG_OF */ | |
835 | ||
836 | #if IS_ENABLED(CONFIG_ACPI) | |
837 | u32 i2c_acpi_find_bus_speed(struct device *dev); | |
838 | struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, | |
839 | struct i2c_board_info *info); | |
840 | #else | |
841 | static inline u32 i2c_acpi_find_bus_speed(struct device *dev) | |
842 | { | |
843 | return 0; | |
844 | } | |
845 | static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, | |
846 | int index, struct i2c_board_info *info) | |
847 | { | |
848 | return NULL; | |
849 | } | |
850 | #endif /* CONFIG_ACPI */ | |
851 | ||
852 | #endif /* _LINUX_I2C_H */ |