1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3 * i2c.h - definitions for the Linux i2c bus interface
4 * Copyright (C) 1995-2000 Simon G. Vogl
5 * Copyright (C) 2013-2019 Wolfram Sang <wsa@kernel.org>
6 *
7 * With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
8 * Frodo Looijaard <frodol@dds.nl>
9 */
10 #ifndef _LINUX_I2C_H
11 #define _LINUX_I2C_H
12
13 #include <linux/acpi.h> /* for acpi_handle */
14 #include <linux/mod_devicetable.h>
15 #include <linux/device.h> /* for struct device */
16 #include <linux/sched.h> /* for completion */
17 #include <linux/mutex.h>
18 #include <linux/rtmutex.h>
19 #include <linux/irqdomain.h> /* for Host Notify IRQ */
20 #include <linux/of.h> /* for struct device_node */
21 #include <linux/swab.h> /* for swab16 */
22 #include <uapi/linux/i2c.h>
23
24 extern struct bus_type i2c_bus_type;
25 extern struct device_type i2c_adapter_type;
26 extern struct device_type i2c_client_type;
27
28 /* --- General options ------------------------------------------------ */
29
30 struct i2c_msg;
31 struct i2c_algorithm;
32 struct i2c_adapter;
33 struct i2c_client;
34 struct i2c_driver;
35 struct i2c_device_identity;
36 union i2c_smbus_data;
37 struct i2c_board_info;
38 enum i2c_slave_event;
39 typedef int (*i2c_slave_cb_t)(struct i2c_client *client, enum i2c_slave_event event, u8 *val);
40
41 /* I2C Frequency Modes */
42 #define I2C_MAX_STANDARD_MODE_FREQ 100000
43 #define I2C_MAX_FAST_MODE_FREQ 400000
44 #define I2C_MAX_FAST_MODE_PLUS_FREQ 1000000
45 #define I2C_MAX_TURBO_MODE_FREQ 1400000
46 #define I2C_MAX_HIGH_SPEED_MODE_FREQ 3400000
47 #define I2C_MAX_ULTRA_FAST_MODE_FREQ 5000000
48
49 struct module;
50 struct property_entry;
51
52 #if IS_ENABLED(CONFIG_I2C)
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 less than 64k since msg.len is u16.
59 */
60 int i2c_transfer_buffer_flags(const struct i2c_client *client, char *buf, int count, u16 flags);
61
62 /**
63 * i2c_master_recv - issue a single I2C message in master receive mode
64 * @client: Handle to slave device
65 * @buf: Where to store data read from slave
66 * @count: How many bytes to read, must be less than 64k since msg.len is u16
67 *
68 * Returns negative errno, or else the number of bytes read.
69 */
i2c_master_recv(const struct i2c_client * client,char * buf,int count)70 static inline int i2c_master_recv(const struct i2c_client *client, char *buf, int count)
71 {
72 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD);
73 };
74
75 /**
76 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode
77 * using a DMA safe buffer
78 * @client: Handle to slave device
79 * @buf: Where to store data read from slave, must be safe to use with DMA
80 * @count: How many bytes to read, must be less than 64k since msg.len is u16
81 *
82 * Returns negative errno, or else the number of bytes read.
83 */
i2c_master_recv_dmasafe(const struct i2c_client * client,char * buf,int count)84 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, char *buf, int count)
85 {
86 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD | I2C_M_DMA_SAFE);
87 };
88
89 /**
90 * i2c_master_send - issue a single I2C message in master transmit mode
91 * @client: Handle to slave device
92 * @buf: Data that will be written to the slave
93 * @count: How many bytes to write, must be less than 64k since msg.len is u16
94 *
95 * Returns negative errno, or else the number of bytes written.
96 */
i2c_master_send(const struct i2c_client * client,const char * buf,int count)97 static inline int i2c_master_send(const struct i2c_client *client, const char *buf, int count)
98 {
99 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0);
100 };
101
102 /**
103 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode
104 * using a DMA safe buffer
105 * @client: Handle to slave device
106 * @buf: Data that will be written to the slave, must be safe to use with DMA
107 * @count: How many bytes to write, must be less than 64k since msg.len is u16
108 *
109 * Returns negative errno, or else the number of bytes written.
110 */
i2c_master_send_dmasafe(const struct i2c_client * client,const char * buf,int count)111 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, const char *buf, int count)
112 {
113 return i2c_transfer_buffer_flags(client, (char *)buf, count, I2C_M_DMA_SAFE);
114 };
115
116 /* Transfer num messages.
117 */
118 int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
119 /* Unlocked flavor */
120 int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
121
122 /* This is the very generalized SMBus access routine. You probably do not
123 want to use this, though; one of the functions below may be much easier,
124 and probably just as fast.
125 Note that we use i2c_adapter here, because you do not need a specific
126 smbus adapter to call this function. */
127 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, char read_write, u8 command,
128 int protocol, union i2c_smbus_data *data);
129
130 /* Unlocked flavor */
131 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, unsigned short flags, char read_write, u8 command,
132 int protocol, union i2c_smbus_data *data);
133
134 /* Now follow the 'nice' access routines. These also document the calling
135 conventions of i2c_smbus_xfer. */
136
137 s32 i2c_smbus_read_byte(const struct i2c_client *client);
138 s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
139 s32 i2c_smbus_read_byte_data(const struct i2c_client *client, u8 command);
140 s32 i2c_smbus_write_byte_data(const struct i2c_client *client, u8 command, u8 value);
141 s32 i2c_smbus_read_word_data(const struct i2c_client *client, u8 command);
142 s32 i2c_smbus_write_word_data(const struct i2c_client *client, u8 command, u16 value);
143
i2c_smbus_read_word_swapped(const struct i2c_client * client,u8 command)144 static inline s32 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
145 {
146 s32 value = i2c_smbus_read_word_data(client, command);
147
148 return (value < 0) ? value : swab16(value);
149 }
150
i2c_smbus_write_word_swapped(const struct i2c_client * client,u8 command,u16 value)151 static inline s32 i2c_smbus_write_word_swapped(const struct i2c_client *client, u8 command, u16 value)
152 {
153 return i2c_smbus_write_word_data(client, command, swab16(value));
154 }
155
156 /* Returns the number of read bytes */
157 s32 i2c_smbus_read_block_data(const struct i2c_client *client, u8 command, u8 *values);
158 s32 i2c_smbus_write_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values);
159 /* Returns the number of read bytes */
160 s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, u8 *values);
161 s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, u8 command, u8 length, const u8 *values);
162 s32 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, u8 command, u8 length, u8 *values);
163 int i2c_get_device_id(const struct i2c_client *client, struct i2c_device_identity *id);
164 #endif /* I2C */
165
166 /**
167 * struct i2c_device_identity - i2c client device identification
168 * @manufacturer_id: 0 - 4095, database maintained by NXP
169 * @part_id: 0 - 511, according to manufacturer
170 * @die_revision: 0 - 7, according to manufacturer
171 */
172 struct i2c_device_identity {
173 u16 manufacturer_id;
174 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0
175 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1
176 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2
177 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3
178 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4
179 #define I2C_DEVICE_ID_ANALOG_DEVICES 5
180 #define I2C_DEVICE_ID_STMICROELECTRONICS 6
181 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7
182 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8
183 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9
184 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10
185 #define I2C_DEVICE_ID_FLIR 11
186 #define I2C_DEVICE_ID_O2MICRO 12
187 #define I2C_DEVICE_ID_ATMEL 13
188 #define I2C_DEVICE_ID_NONE 0xffff
189 u16 part_id;
190 u8 die_revision;
191 };
192
193 enum i2c_alert_protocol {
194 I2C_PROTOCOL_SMBUS_ALERT,
195 I2C_PROTOCOL_SMBUS_HOST_NOTIFY,
196 };
197
198 /**
199 * struct i2c_driver - represent an I2C device driver
200 * @class: What kind of i2c device we instantiate (for detect)
201 * @probe: Callback for device binding - soon to be deprecated
202 * @probe_new: New callback for device binding
203 * @remove: Callback for device unbinding
204 * @shutdown: Callback for device shutdown
205 * @alert: Alert callback, for example for the SMBus alert protocol
206 * @command: Callback for bus-wide signaling (optional)
207 * @driver: Device driver model driver
208 * @id_table: List of I2C devices supported by this driver
209 * @detect: Callback for device detection
210 * @address_list: The I2C addresses to probe (for detect)
211 * @clients: List of detected clients we created (for i2c-core use only)
212 *
213 * The driver.owner field should be set to the module owner of this driver.
214 * The driver.name field should be set to the name of this driver.
215 *
216 * For automatic device detection, both @detect and @address_list must
217 * be defined. @class should also be set, otherwise only devices forced
218 * with module parameters will be created. The detect function must
219 * fill at least the name field of the i2c_board_info structure it is
220 * handed upon successful detection, and possibly also the flags field.
221 *
222 * If @detect is missing, the driver will still work fine for enumerated
223 * devices. Detected devices simply won't be supported. This is expected
224 * for the many I2C/SMBus devices which can't be detected reliably, and
225 * the ones which can always be enumerated in practice.
226 *
227 * The i2c_client structure which is handed to the @detect callback is
228 * not a real i2c_client. It is initialized just enough so that you can
229 * call i2c_smbus_read_byte_data and friends on it. Don't do anything
230 * else with it. In particular, calling dev_dbg and friends on it is
231 * not allowed.
232 */
233 struct i2c_driver {
234 unsigned int class;
235
236 /* Standard driver model interfaces */
237 int (*probe)(struct i2c_client *client, const struct i2c_device_id *id);
238 int (*remove)(struct i2c_client *client);
239
240 /* New driver model interface to aid the seamless removal of the
241 * current probe()'s, more commonly unused than used second parameter.
242 */
243 int (*probe_new)(struct i2c_client *client);
244
245 /* driver model interfaces that don't relate to enumeration */
246 void (*shutdown)(struct i2c_client *client);
247
248 /* Alert callback, for example for the SMBus alert protocol.
249 * The format and meaning of the data value depends on the protocol.
250 * For the SMBus alert protocol, there is a single bit of data passed
251 * as the alert response's low bit ("event flag").
252 * For the SMBus Host Notify protocol, the data corresponds to the
253 * 16-bit payload data reported by the slave device acting as master.
254 */
255 void (*alert)(struct i2c_client *client, enum i2c_alert_protocol protocol, unsigned int data);
256
257 /* a ioctl like command that can be used to perform specific functions
258 * with the device.
259 */
260 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
261
262 struct device_driver driver;
263 const struct i2c_device_id *id_table;
264
265 /* Device detection callback for automatic device creation */
266 int (*detect)(struct i2c_client *client, struct i2c_board_info *info);
267 const unsigned short *address_list;
268 struct list_head clients;
269 };
270 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
271
272 /**
273 * struct i2c_client - represent an I2C slave device
274 * @flags: see I2C_CLIENT_* for possible flags
275 * @addr: Address used on the I2C bus connected to the parent adapter.
276 * @name: Indicates the type of the device, usually a chip name that's
277 * generic enough to hide second-sourcing and compatible revisions.
278 * @adapter: manages the bus segment hosting this I2C device
279 * @dev: Driver model device node for the slave.
280 * @init_irq: IRQ that was set at initialization
281 * @irq: indicates the IRQ generated by this device (if any)
282 * @detected: member of an i2c_driver.clients list or i2c-core's
283 * userspace_devices list
284 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
285 * calls it to pass on slave events to the slave driver.
286 *
287 * An i2c_client identifies a single device (i.e. chip) connected to an
288 * i2c bus. The behaviour exposed to Linux is defined by the driver
289 * managing the device.
290 */
291 struct i2c_client {
292 unsigned short flags; /* div., see below */
293 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */
294 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */
295 /* Must equal I2C_M_TEN below */
296 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */
297 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */
298 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */
299 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */
300 /* Must match I2C_M_STOP|IGNORE_NAK */
301
302 unsigned short addr; /* chip address - NOTE: 7bit */
303 /* addresses are stored in the */
304 /* _LOWER_ 7 bits */
305 char name[I2C_NAME_SIZE];
306 struct i2c_adapter *adapter; /* the adapter we sit on */
307 struct device dev; /* the device structure */
308 int init_irq; /* irq set at initialization */
309 int irq; /* irq issued by device */
310 struct list_head detected;
311 #if IS_ENABLED(CONFIG_I2C_SLAVE)
312 i2c_slave_cb_t slave_cb; /* callback for slave mode */
313 #endif
314 };
315 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
316
317 struct i2c_client *i2c_verify_client(struct device *dev);
318 struct i2c_adapter *i2c_verify_adapter(struct device *dev);
319 const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, const struct i2c_client *client);
320
kobj_to_i2c_client(struct kobject * kobj)321 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
322 {
323 struct device *const dev = kobj_to_dev(kobj);
324 return to_i2c_client(dev);
325 }
326
i2c_get_clientdata(const struct i2c_client * client)327 static inline void *i2c_get_clientdata(const struct i2c_client *client)
328 {
329 return dev_get_drvdata(&client->dev);
330 }
331
i2c_set_clientdata(struct i2c_client * client,void * data)332 static inline void i2c_set_clientdata(struct i2c_client *client, void *data)
333 {
334 dev_set_drvdata(&client->dev, data);
335 }
336
337 /* I2C slave support */
338
339 #if IS_ENABLED(CONFIG_I2C_SLAVE)
340 enum i2c_slave_event {
341 I2C_SLAVE_READ_REQUESTED,
342 I2C_SLAVE_WRITE_REQUESTED,
343 I2C_SLAVE_READ_PROCESSED,
344 I2C_SLAVE_WRITE_RECEIVED,
345 I2C_SLAVE_STOP,
346 };
347
348 int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb);
349 int i2c_slave_unregister(struct i2c_client *client);
350 bool i2c_detect_slave_mode(struct device *dev);
351
i2c_slave_event(struct i2c_client * client,enum i2c_slave_event event,u8 * val)352 static inline int i2c_slave_event(struct i2c_client *client, enum i2c_slave_event event, u8 *val)
353 {
354 return client->slave_cb(client, event, val);
355 }
356 #else
i2c_detect_slave_mode(struct device * dev)357 static inline bool i2c_detect_slave_mode(struct device *dev)
358 {
359 return false;
360 }
361 #endif
362
363 /**
364 * struct i2c_board_info - template for device creation
365 * @type: chip type, to initialize i2c_client.name
366 * @flags: to initialize i2c_client.flags
367 * @addr: stored in i2c_client.addr
368 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set
369 * @platform_data: stored in i2c_client.dev.platform_data
370 * @of_node: pointer to OpenFirmware device node
371 * @fwnode: device node supplied by the platform firmware
372 * @properties: additional device properties for the device
373 * @resources: resources associated with the device
374 * @num_resources: number of resources in the @resources array
375 * @irq: stored in i2c_client.irq
376 *
377 * I2C doesn't actually support hardware probing, although controllers and
378 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
379 * a device at a given address. Drivers commonly need more information than
380 * that, such as chip type, configuration, associated IRQ, and so on.
381 *
382 * i2c_board_info is used to build tables of information listing I2C devices
383 * that are present. This information is used to grow the driver model tree.
384 * For mainboards this is done statically using i2c_register_board_info();
385 * bus numbers identify adapters that aren't yet available. For add-on boards,
386 * i2c_new_client_device() does this dynamically with the adapter already known.
387 */
388 struct i2c_board_info {
389 char type[I2C_NAME_SIZE];
390 unsigned short flags;
391 unsigned short addr;
392 const char *dev_name;
393 void *platform_data;
394 struct device_node *of_node;
395 struct fwnode_handle *fwnode;
396 const struct property_entry *properties;
397 const struct resource *resources;
398 unsigned int num_resources;
399 int irq;
400 };
401
402 /**
403 * I2C_BOARD_INFO - macro used to list an i2c device and its address
404 * @dev_type: identifies the device type
405 * @dev_addr: the device's address on the bus.
406 *
407 * This macro initializes essential fields of a struct i2c_board_info,
408 * declaring what has been provided on a particular board. Optional
409 * fields (such as associated irq, or device-specific platform_data)
410 * are provided using conventional syntax.
411 */
412 #define I2C_BOARD_INFO(dev_type, dev_addr) .type = (dev_type), .addr = (dev_addr)
413
414 #if IS_ENABLED(CONFIG_I2C)
415 /*
416 * Add-on boards should register/unregister their devices; e.g. a board
417 * with integrated I2C, a config eeprom, sensors, and a codec that's
418 * used in conjunction with the primary hardware.
419 */
420 struct i2c_client *i2c_new_client_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
421
422 /* If you don't know the exact address of an I2C device, use this variant
423 * instead, which can probe for device presence in a list of possible
424 * addresses. The "probe" callback function is optional. If it is provided,
425 * it must return 1 on successful probe, 0 otherwise. If it is not provided,
426 * a default probing method is used.
427 */
428 struct i2c_client *i2c_new_scanned_device(struct i2c_adapter *adap, struct i2c_board_info *info,
429 unsigned short const *addr_list,
430 int (*probe)(struct i2c_adapter *adap, unsigned short addr));
431
432 /* Common custom probe functions */
433 int i2c_probe_func_quick_read(struct i2c_adapter *adap, unsigned short addr);
434
435 struct i2c_client *i2c_new_dummy_device(struct i2c_adapter *adapter, u16 address);
436
437 struct i2c_client *devm_i2c_new_dummy_device(struct device *dev, struct i2c_adapter *adap, u16 address);
438
439 struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, const char *name, u16 default_addr);
440
441 void i2c_unregister_device(struct i2c_client *client);
442 #endif /* I2C */
443
444 /* Mainboard arch_initcall() code should register all its I2C devices.
445 * This is done at arch_initcall time, before declaring any i2c adapters.
446 * Modules for add-on boards must use other calls.
447 */
448 #ifdef CONFIG_I2C_BOARDINFO
449 int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned n);
450 #else
i2c_register_board_info(int busnum,struct i2c_board_info const * info,unsigned n)451 static inline int i2c_register_board_info(int busnum, struct i2c_board_info const *info, unsigned n)
452 {
453 return 0;
454 }
455 #endif /* I2C_BOARDINFO */
456
457 /**
458 * struct i2c_algorithm - represent I2C transfer method
459 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
460 * defined by the msgs array, with num messages available to transfer via
461 * the adapter specified by adap.
462 * @master_xfer_atomic: same as @master_xfer. Yet, only using atomic context
463 * so e.g. PMICs can be accessed very late before shutdown. Optional.
464 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
465 * is not present, then the bus layer will try and convert the SMBus calls
466 * into I2C transfers instead.
467 * @smbus_xfer_atomic: same as @smbus_xfer. Yet, only using atomic context
468 * so e.g. PMICs can be accessed very late before shutdown. Optional.
469 * @functionality: Return the flags that this algorithm/adapter pair supports
470 * from the ``I2C_FUNC_*`` flags.
471 * @reg_slave: Register given client to I2C slave mode of this adapter
472 * @unreg_slave: Unregister given client from I2C slave mode of this adapter
473 *
474 * The following structs are for those who like to implement new bus drivers:
475 * i2c_algorithm is the interface to a class of hardware solutions which can
476 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
477 * to name two of the most common.
478 *
479 * The return codes from the ``master_xfer{_atomic}`` fields should indicate the
480 * type of error code that occurred during the transfer, as documented in the
481 * Kernel Documentation file Documentation/i2c/fault-codes.rst.
482 */
483 struct i2c_algorithm {
484 /*
485 * If an adapter algorithm can't do I2C-level access, set master_xfer
486 * to NULL. If an adapter algorithm can do SMBus access, set
487 * smbus_xfer. If set to NULL, the SMBus protocol is simulated
488 * using common I2C messages.
489 *
490 * master_xfer should return the number of messages successfully
491 * processed, or a negative value on error
492 */
493 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
494 int (*master_xfer_atomic)(struct i2c_adapter *adap, struct i2c_msg *msgs, int num);
495 int (*smbus_xfer)(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command, int size,
496 union i2c_smbus_data *data);
497 int (*smbus_xfer_atomic)(struct i2c_adapter *adap, u16 addr, unsigned short flags, char read_write, u8 command,
498 int size, union i2c_smbus_data *data);
499
500 /* To determine what the adapter supports */
501 u32 (*functionality)(struct i2c_adapter *adap);
502
503 #if IS_ENABLED(CONFIG_I2C_SLAVE)
504 int (*reg_slave)(struct i2c_client *client);
505 int (*unreg_slave)(struct i2c_client *client);
506 #endif
507 };
508
509 /**
510 * struct i2c_lock_operations - represent I2C locking operations
511 * @lock_bus: Get exclusive access to an I2C bus segment
512 * @trylock_bus: Try to get exclusive access to an I2C bus segment
513 * @unlock_bus: Release exclusive access to an I2C bus segment
514 *
515 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus.
516 */
517 struct i2c_lock_operations {
518 void (*lock_bus)(struct i2c_adapter *adapter, unsigned int flags);
519 int (*trylock_bus)(struct i2c_adapter *adapter, unsigned int flags);
520 void (*unlock_bus)(struct i2c_adapter *adapter, unsigned int flags);
521 };
522
523 /**
524 * struct i2c_timings - I2C timing information
525 * @bus_freq_hz: the bus frequency in Hz
526 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification
527 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification
528 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns
529 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification
530 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns
531 * @digital_filter_width_ns: width in ns of spikes on i2c lines that the IP core
532 * digital filter can filter out
533 * @analog_filter_cutoff_freq_hz: threshold frequency for the low pass IP core
534 * analog filter
535 */
536 struct i2c_timings {
537 u32 bus_freq_hz;
538 u32 scl_rise_ns;
539 u32 scl_fall_ns;
540 u32 scl_int_delay_ns;
541 u32 sda_fall_ns;
542 u32 sda_hold_ns;
543 u32 digital_filter_width_ns;
544 u32 analog_filter_cutoff_freq_hz;
545 };
546
547 /**
548 * struct i2c_bus_recovery_info - I2C bus recovery information
549 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
550 * i2c_generic_scl_recovery().
551 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
552 * recovery. Populated internally for generic GPIO recovery.
553 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery.
554 * Populated internally for generic GPIO recovery.
555 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory
556 * for generic SCL recovery. Populated internally, if sda_gpio is a valid
557 * GPIO, for generic GPIO recovery.
558 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for
559 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO,
560 * for generic GPIO recovery.
561 * @get_bus_free: Returns the bus free state as seen from the IP core in case it
562 * has a more complex internal logic than just reading SDA. Optional.
563 * @prepare_recovery: This will be called before starting recovery. Platform may
564 * configure padmux here for SDA/SCL line or something else they want.
565 * @unprepare_recovery: This will be called after completing recovery. Platform
566 * may configure padmux here for SDA/SCL line or something else they want.
567 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery.
568 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery.
569 * @pinctrl: pinctrl used by GPIO recovery to change the state of the I2C pins.
570 * Optional.
571 * @pins_default: default pinctrl state of SCL/SDA lines, when they are assigned
572 * to the I2C bus. Optional. Populated internally for GPIO recovery, if
573 * state with the name PINCTRL_STATE_DEFAULT is found and pinctrl is valid.
574 * @pins_gpio: recovery pinctrl state of SCL/SDA lines, when they are used as
575 * GPIOs. Optional. Populated internally for GPIO recovery, if this state
576 * is called "gpio" or "recovery" and pinctrl is valid.
577 */
578 struct i2c_bus_recovery_info {
579 int (*recover_bus)(struct i2c_adapter *adap);
580
581 int (*get_scl)(struct i2c_adapter *adap);
582 void (*set_scl)(struct i2c_adapter *adap, int val);
583 int (*get_sda)(struct i2c_adapter *adap);
584 void (*set_sda)(struct i2c_adapter *adap, int val);
585 int (*get_bus_free)(struct i2c_adapter *adap);
586
587 void (*prepare_recovery)(struct i2c_adapter *adap);
588 void (*unprepare_recovery)(struct i2c_adapter *adap);
589
590 /* gpio recovery */
591 struct gpio_desc *scl_gpiod;
592 struct gpio_desc *sda_gpiod;
593 struct pinctrl *pinctrl;
594 struct pinctrl_state *pins_default;
595 struct pinctrl_state *pins_gpio;
596 };
597
598 int i2c_recover_bus(struct i2c_adapter *adap);
599
600 /* Generic recovery routines */
601 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
602
603 /**
604 * struct i2c_adapter_quirks - describe flaws of an i2c adapter
605 * @flags: see I2C_AQ_* for possible flags and read below
606 * @max_num_msgs: maximum number of messages per transfer
607 * @max_write_len: maximum length of a write message
608 * @max_read_len: maximum length of a read message
609 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message
610 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message
611 *
612 * Note about combined messages: Some I2C controllers can only send one message
613 * per transfer, plus something called combined message or write-then-read.
614 * This is (usually) a small write message followed by a read message and
615 * barely enough to access register based devices like EEPROMs. There is a flag
616 * to support this mode. It implies max_num_msg = 2 and does the length checks
617 * with max_comb_*_len because combined message mode usually has its own
618 * limitations. Because of HW implementations, some controllers can actually do
619 * write-then-anything or other variants. To support that, write-then-read has
620 * been broken out into smaller bits like write-first and read-second which can
621 * be combined as needed.
622 */
623
624 struct i2c_adapter_quirks {
625 u64 flags;
626 int max_num_msgs;
627 u16 max_write_len;
628 u16 max_read_len;
629 u16 max_comb_1st_msg_len;
630 u16 max_comb_2nd_msg_len;
631 };
632
633 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */
634 #define I2C_AQ_COMB BIT(0)
635 /* first combined message must be write */
636 #define I2C_AQ_COMB_WRITE_FIRST BIT(1)
637 /* second combined message must be read */
638 #define I2C_AQ_COMB_READ_SECOND BIT(2)
639 /* both combined messages must have the same target address */
640 #define I2C_AQ_COMB_SAME_ADDR BIT(3)
641 /* convenience macro for typical write-then read case */
642 #define I2C_AQ_COMB_WRITE_THEN_READ \
643 (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR)
644 /* clock stretching is not supported */
645 #define I2C_AQ_NO_CLK_STRETCH BIT(4)
646 /* message cannot have length of 0 */
647 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5)
648 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6)
649 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE)
650 /* adapter cannot do repeated START */
651 #define I2C_AQ_NO_REP_START BIT(7)
652
653 /*
654 * i2c_adapter is the structure used to identify a physical i2c bus along
655 * with the access algorithms necessary to access it.
656 */
657 struct i2c_adapter {
658 struct module *owner;
659 unsigned int class; /* classes to allow probing for */
660 const struct i2c_algorithm *algo; /* the algorithm to access the bus */
661 void *algo_data;
662
663 /* data fields that are valid for all devices */
664 const struct i2c_lock_operations *lock_ops;
665 struct rt_mutex bus_lock;
666 struct rt_mutex mux_lock;
667
668 int timeout; /* in jiffies */
669 int retries;
670 struct device dev; /* the adapter device */
671 unsigned long locked_flags; /* owned by the I2C core */
672 #define I2C_ALF_IS_SUSPENDED 0
673 #define I2C_ALF_SUSPEND_REPORTED 1
674
675 int nr;
676 char name[48];
677 struct completion dev_released;
678
679 struct mutex userspace_clients_lock;
680 struct list_head userspace_clients;
681
682 struct i2c_bus_recovery_info *bus_recovery_info;
683 const struct i2c_adapter_quirks *quirks;
684
685 struct irq_domain *host_notify_domain;
686 };
687 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
688
i2c_get_adapdata(const struct i2c_adapter * adap)689 static inline void *i2c_get_adapdata(const struct i2c_adapter *adap)
690 {
691 return dev_get_drvdata(&adap->dev);
692 }
693
i2c_set_adapdata(struct i2c_adapter * adap,void * data)694 static inline void i2c_set_adapdata(struct i2c_adapter *adap, void *data)
695 {
696 dev_set_drvdata(&adap->dev, data);
697 }
698
i2c_parent_is_i2c_adapter(const struct i2c_adapter * adapter)699 static inline struct i2c_adapter *i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
700 {
701 #if IS_ENABLED(CONFIG_I2C_MUX)
702 struct device *parent = adapter->dev.parent;
703
704 if (parent != NULL && parent->type == &i2c_adapter_type) {
705 return to_i2c_adapter(parent);
706 } else
707 #endif
708 return NULL;
709 }
710
711 int i2c_for_each_dev(void *data, int (*fn)(struct device *dev, void *data));
712
713 /* Adapter locking functions, exported for shared pin cases */
714 #define I2C_LOCK_ROOT_ADAPTER BIT(0)
715 #define I2C_LOCK_SEGMENT BIT(1)
716
717 /**
718 * i2c_lock_bus - Get exclusive access to an I2C bus segment
719 * @adapter: Target I2C bus segment
720 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT
721 * locks only this branch in the adapter tree
722 */
i2c_lock_bus(struct i2c_adapter * adapter,unsigned int flags)723 static inline void i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags)
724 {
725 adapter->lock_ops->lock_bus(adapter, flags);
726 }
727
728 /**
729 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment
730 * @adapter: Target I2C bus segment
731 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter,
732 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree
733 *
734 * Return: true if the I2C bus segment is locked, false otherwise
735 */
i2c_trylock_bus(struct i2c_adapter * adapter,unsigned int flags)736 static inline int i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags)
737 {
738 return adapter->lock_ops->trylock_bus(adapter, flags);
739 }
740
741 /**
742 * i2c_unlock_bus - Release exclusive access to an I2C bus segment
743 * @adapter: Target I2C bus segment
744 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT
745 * unlocks only this branch in the adapter tree
746 */
i2c_unlock_bus(struct i2c_adapter * adapter,unsigned int flags)747 static inline void i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags)
748 {
749 adapter->lock_ops->unlock_bus(adapter, flags);
750 }
751
752 /**
753 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core
754 * @adap: Adapter to mark as suspended
755 *
756 * When using this helper to mark an adapter as suspended, the core will reject
757 * further transfers to this adapter. The usage of this helper is optional but
758 * recommended for devices having distinct handlers for system suspend and
759 * runtime suspend. More complex devices are free to implement custom solutions
760 * to reject transfers when suspended.
761 */
i2c_mark_adapter_suspended(struct i2c_adapter * adap)762 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap)
763 {
764 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
765 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
766 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
767 }
768
769 /**
770 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core
771 * @adap: Adapter to mark as resumed
772 *
773 * When using this helper to mark an adapter as resumed, the core will allow
774 * further transfers to this adapter. See also further notes to
775 * @i2c_mark_adapter_suspended().
776 */
i2c_mark_adapter_resumed(struct i2c_adapter * adap)777 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap)
778 {
779 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
780 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags);
781 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER);
782 }
783
784 /* i2c adapter classes (bitmask) */
785 #define I2C_CLASS_HWMON (1 << 0) /* lm_sensors, ... */
786 #define I2C_CLASS_DDC (1 << 3) /* DDC bus on graphics adapters */
787 #define I2C_CLASS_SPD (1 << 7) /* Memory modules */
788 /* Warn users that the adapter doesn't support classes anymore */
789 #define I2C_CLASS_DEPRECATED (1 << 8)
790
791 /* Internal numbers to terminate lists */
792 #define I2C_CLIENT_END 0xfffeU
793
794 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
795 #define I2C_ADDRS(addr, addrs...) ((const unsigned short[]) {addr, ##addrs, I2C_CLIENT_END})
796
797 /* ----- functions exported by i2c.o */
798
799 /* administration...
800 */
801 #if IS_ENABLED(CONFIG_I2C)
802 int i2c_add_adapter(struct i2c_adapter *adap);
803 void i2c_del_adapter(struct i2c_adapter *adap);
804 int i2c_add_numbered_adapter(struct i2c_adapter *adap);
805
806 int i2c_register_driver(struct module *owner, struct i2c_driver *driver);
807 void i2c_del_driver(struct i2c_driver *driver);
808
809 /* use a define to avoid include chaining to get THIS_MODULE */
810 #define i2c_add_driver(driver) i2c_register_driver(THIS_MODULE, driver)
811
i2c_client_has_driver(struct i2c_client * client)812 static inline bool i2c_client_has_driver(struct i2c_client *client)
813 {
814 return !IS_ERR_OR_NULL(client) && client->dev.driver;
815 }
816
817 /* call the i2c_client->command() of all attached clients with
818 * the given arguments */
819 void i2c_clients_command(struct i2c_adapter *adap, unsigned int cmd, void *arg);
820
821 struct i2c_adapter *i2c_get_adapter(int nr);
822 void i2c_put_adapter(struct i2c_adapter *adap);
823 unsigned int i2c_adapter_depth(struct i2c_adapter *adapter);
824
825 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults);
826
827 /* Return the functionality mask */
i2c_get_functionality(struct i2c_adapter * adap)828 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
829 {
830 return adap->algo->functionality(adap);
831 }
832
833 /* Return 1 if adapter supports everything we need, 0 if not. */
i2c_check_functionality(struct i2c_adapter * adap,u32 func)834 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
835 {
836 return (func & i2c_get_functionality(adap)) == func;
837 }
838
839 /**
840 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter
841 * @adap: i2c adapter
842 * @quirks: quirk flags
843 *
844 * Return: true if the adapter has all the specified quirk flags, false if not
845 */
i2c_check_quirks(struct i2c_adapter * adap,u64 quirks)846 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks)
847 {
848 if (!adap->quirks) {
849 return false;
850 }
851 return (adap->quirks->flags & quirks) == quirks;
852 }
853
854 /* Return the adapter number for a specific adapter */
i2c_adapter_id(struct i2c_adapter * adap)855 static inline int i2c_adapter_id(struct i2c_adapter *adap)
856 {
857 return adap->nr;
858 }
859
i2c_8bit_addr_from_msg(const struct i2c_msg * msg)860 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
861 {
862 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
863 }
864
865 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold);
866 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred);
867
868 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr);
869 /**
870 * module_i2c_driver() - Helper macro for registering a modular I2C driver
871 * @__i2c_driver: i2c_driver struct
872 *
873 * Helper macro for I2C drivers which do not do anything special in module
874 * init/exit. This eliminates a lot of boilerplate. Each module may only
875 * use this macro once, and calling it replaces module_init() and module_exit()
876 */
877 #define module_i2c_driver(__i2c_driver) module_driver(__i2c_driver, i2c_add_driver, i2c_del_driver)
878
879 /**
880 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver
881 * @__i2c_driver: i2c_driver struct
882 *
883 * Helper macro for I2C drivers which do not do anything special in their
884 * init. This eliminates a lot of boilerplate. Each driver may only
885 * use this macro once, and calling it replaces device_initcall().
886 */
887 #define builtin_i2c_driver(__i2c_driver) builtin_driver(__i2c_driver, i2c_add_driver)
888
889 #endif /* I2C */
890
891 #if IS_ENABLED(CONFIG_OF)
892 /* must call put_device() when done with returned i2c_client device */
893 struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
894
895 /* must call put_device() when done with returned i2c_adapter device */
896 struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
897
898 /* must call i2c_put_adapter() when done with returned i2c_adapter device */
899 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node);
900
901 const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches, struct i2c_client *client);
902
903 int of_i2c_get_board_info(struct device *dev, struct device_node *node, struct i2c_board_info *info);
904
905 #else
906
of_find_i2c_device_by_node(struct device_node * node)907 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
908 {
909 return NULL;
910 }
911
of_find_i2c_adapter_by_node(struct device_node * node)912 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
913 {
914 return NULL;
915 }
916
of_get_i2c_adapter_by_node(struct device_node * node)917 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node)
918 {
919 return NULL;
920 }
921
i2c_of_match_device(const struct of_device_id * matches,struct i2c_client * client)922 static inline const struct of_device_id *i2c_of_match_device(const struct of_device_id *matches,
923 struct i2c_client *client)
924 {
925 return NULL;
926 }
927
of_i2c_get_board_info(struct device * dev,struct device_node * node,struct i2c_board_info * info)928 static inline int of_i2c_get_board_info(struct device *dev, struct device_node *node, struct i2c_board_info *info)
929 {
930 return -ENOTSUPP;
931 }
932
933 #endif /* CONFIG_OF */
934
935 struct acpi_resource;
936 struct acpi_resource_i2c_serialbus;
937
938 #if IS_ENABLED(CONFIG_ACPI)
939 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c);
940 u32 i2c_acpi_find_bus_speed(struct device *dev);
941 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info);
942 struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle);
943 #else
i2c_acpi_get_i2c_resource(struct acpi_resource * ares,struct acpi_resource_i2c_serialbus ** i2c)944 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, struct acpi_resource_i2c_serialbus **i2c)
945 {
946 return false;
947 }
i2c_acpi_find_bus_speed(struct device * dev)948 static inline u32 i2c_acpi_find_bus_speed(struct device *dev)
949 {
950 return 0;
951 }
i2c_acpi_new_device(struct device * dev,int index,struct i2c_board_info * info)952 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, struct i2c_board_info *info)
953 {
954 return ERR_PTR(-ENODEV);
955 }
i2c_acpi_find_adapter_by_handle(acpi_handle handle)956 static inline struct i2c_adapter *i2c_acpi_find_adapter_by_handle(acpi_handle handle)
957 {
958 return NULL;
959 }
960 #endif /* CONFIG_ACPI */
961
962 #endif /* _LINUX_I2C_H */
963