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 struct i2c_device_identity; 51 union i2c_smbus_data; 52 struct i2c_board_info; 53 enum i2c_slave_event; 54 typedef int (*i2c_slave_cb_t)(struct i2c_client *, enum i2c_slave_event, u8 *); 55 56 struct module; 57 struct property_entry; 58 59 #if IS_ENABLED(CONFIG_I2C) 60 /* 61 * The master routines are the ones normally used to transmit data to devices 62 * on a bus (or read from them). Apart from two basic transfer functions to 63 * transmit one message at a time, a more complex version can be used to 64 * transmit an arbitrary number of messages without interruption. 65 * @count must be be less than 64k since msg.len is u16. 66 */ 67 extern int i2c_transfer_buffer_flags(const struct i2c_client *client, 68 char *buf, int count, u16 flags); 69 70 /** 71 * i2c_master_recv - issue a single I2C message in master receive mode 72 * @client: Handle to slave device 73 * @buf: Where to store data read from slave 74 * @count: How many bytes to read, must be less than 64k since msg.len is u16 75 * 76 * Returns negative errno, or else the number of bytes read. 77 */ 78 static inline int i2c_master_recv(const struct i2c_client *client, 79 char *buf, int count) 80 { 81 return i2c_transfer_buffer_flags(client, buf, count, I2C_M_RD); 82 }; 83 84 /** 85 * i2c_master_recv_dmasafe - issue a single I2C message in master receive mode 86 * using a DMA safe buffer 87 * @client: Handle to slave device 88 * @buf: Where to store data read from slave, must be safe to use with DMA 89 * @count: How many bytes to read, must be less than 64k since msg.len is u16 90 * 91 * Returns negative errno, or else the number of bytes read. 92 */ 93 static inline int i2c_master_recv_dmasafe(const struct i2c_client *client, 94 char *buf, int count) 95 { 96 return i2c_transfer_buffer_flags(client, buf, count, 97 I2C_M_RD | I2C_M_DMA_SAFE); 98 }; 99 100 /** 101 * i2c_master_send - issue a single I2C message in master transmit mode 102 * @client: Handle to slave device 103 * @buf: Data that will be written to the slave 104 * @count: How many bytes to write, must be less than 64k since msg.len is u16 105 * 106 * Returns negative errno, or else the number of bytes written. 107 */ 108 static inline int i2c_master_send(const struct i2c_client *client, 109 const char *buf, int count) 110 { 111 return i2c_transfer_buffer_flags(client, (char *)buf, count, 0); 112 }; 113 114 /** 115 * i2c_master_send_dmasafe - issue a single I2C message in master transmit mode 116 * using a DMA safe buffer 117 * @client: Handle to slave device 118 * @buf: Data that will be written to the slave, must be safe to use with DMA 119 * @count: How many bytes to write, must be less than 64k since msg.len is u16 120 * 121 * Returns negative errno, or else the number of bytes written. 122 */ 123 static inline int i2c_master_send_dmasafe(const struct i2c_client *client, 124 const char *buf, int count) 125 { 126 return i2c_transfer_buffer_flags(client, (char *)buf, count, 127 I2C_M_DMA_SAFE); 128 }; 129 130 /* Transfer num messages. 131 */ 132 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 133 int num); 134 /* Unlocked flavor */ 135 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs, 136 int num); 137 138 /* This is the very generalized SMBus access routine. You probably do not 139 want to use this, though; one of the functions below may be much easier, 140 and probably just as fast. 141 Note that we use i2c_adapter here, because you do not need a specific 142 smbus adapter to call this function. */ 143 s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 144 unsigned short flags, char read_write, u8 command, 145 int protocol, union i2c_smbus_data *data); 146 147 /* Unlocked flavor */ 148 s32 __i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr, 149 unsigned short flags, char read_write, u8 command, 150 int protocol, union i2c_smbus_data *data); 151 152 /* Now follow the 'nice' access routines. These also document the calling 153 conventions of i2c_smbus_xfer. */ 154 155 extern s32 i2c_smbus_read_byte(const struct i2c_client *client); 156 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value); 157 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client, 158 u8 command); 159 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client, 160 u8 command, u8 value); 161 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client, 162 u8 command); 163 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client, 164 u8 command, u16 value); 165 166 static inline s32 167 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command) 168 { 169 s32 value = i2c_smbus_read_word_data(client, command); 170 171 return (value < 0) ? value : swab16(value); 172 } 173 174 static inline s32 175 i2c_smbus_write_word_swapped(const struct i2c_client *client, 176 u8 command, u16 value) 177 { 178 return i2c_smbus_write_word_data(client, command, swab16(value)); 179 } 180 181 /* Returns the number of read bytes */ 182 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client, 183 u8 command, u8 *values); 184 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client, 185 u8 command, u8 length, const u8 *values); 186 /* Returns the number of read bytes */ 187 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client, 188 u8 command, u8 length, u8 *values); 189 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client, 190 u8 command, u8 length, 191 const u8 *values); 192 extern s32 193 i2c_smbus_read_i2c_block_data_or_emulated(const struct i2c_client *client, 194 u8 command, u8 length, u8 *values); 195 int i2c_get_device_id(const struct i2c_client *client, 196 struct i2c_device_identity *id); 197 #endif /* I2C */ 198 199 /** 200 * struct i2c_device_identity - i2c client device identification 201 * @manufacturer_id: 0 - 4095, database maintained by NXP 202 * @part_id: 0 - 511, according to manufacturer 203 * @die_revision: 0 - 7, according to manufacturer 204 */ 205 struct i2c_device_identity { 206 u16 manufacturer_id; 207 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS 0 208 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_1 1 209 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_2 2 210 #define I2C_DEVICE_ID_NXP_SEMICONDUCTORS_3 3 211 #define I2C_DEVICE_ID_RAMTRON_INTERNATIONAL 4 212 #define I2C_DEVICE_ID_ANALOG_DEVICES 5 213 #define I2C_DEVICE_ID_STMICROELECTRONICS 6 214 #define I2C_DEVICE_ID_ON_SEMICONDUCTOR 7 215 #define I2C_DEVICE_ID_SPRINTEK_CORPORATION 8 216 #define I2C_DEVICE_ID_ESPROS_PHOTONICS_AG 9 217 #define I2C_DEVICE_ID_FUJITSU_SEMICONDUCTOR 10 218 #define I2C_DEVICE_ID_FLIR 11 219 #define I2C_DEVICE_ID_O2MICRO 12 220 #define I2C_DEVICE_ID_ATMEL 13 221 #define I2C_DEVICE_ID_NONE 0xffff 222 u16 part_id; 223 u8 die_revision; 224 }; 225 226 enum i2c_alert_protocol { 227 I2C_PROTOCOL_SMBUS_ALERT, 228 I2C_PROTOCOL_SMBUS_HOST_NOTIFY, 229 }; 230 231 /** 232 * struct i2c_driver - represent an I2C device driver 233 * @class: What kind of i2c device we instantiate (for detect) 234 * @probe: Callback for device binding - soon to be deprecated 235 * @probe_new: New callback for device binding 236 * @remove: Callback for device unbinding 237 * @shutdown: Callback for device shutdown 238 * @alert: Alert callback, for example for the SMBus alert protocol 239 * @command: Callback for bus-wide signaling (optional) 240 * @driver: Device driver model driver 241 * @id_table: List of I2C devices supported by this driver 242 * @detect: Callback for device detection 243 * @address_list: The I2C addresses to probe (for detect) 244 * @clients: List of detected clients we created (for i2c-core use only) 245 * @disable_i2c_core_irq_mapping: Tell the i2c-core to not do irq-mapping 246 * 247 * The driver.owner field should be set to the module owner of this driver. 248 * The driver.name field should be set to the name of this driver. 249 * 250 * For automatic device detection, both @detect and @address_list must 251 * be defined. @class should also be set, otherwise only devices forced 252 * with module parameters will be created. The detect function must 253 * fill at least the name field of the i2c_board_info structure it is 254 * handed upon successful detection, and possibly also the flags field. 255 * 256 * If @detect is missing, the driver will still work fine for enumerated 257 * devices. Detected devices simply won't be supported. This is expected 258 * for the many I2C/SMBus devices which can't be detected reliably, and 259 * the ones which can always be enumerated in practice. 260 * 261 * The i2c_client structure which is handed to the @detect callback is 262 * not a real i2c_client. It is initialized just enough so that you can 263 * call i2c_smbus_read_byte_data and friends on it. Don't do anything 264 * else with it. In particular, calling dev_dbg and friends on it is 265 * not allowed. 266 */ 267 struct i2c_driver { 268 unsigned int class; 269 270 /* Standard driver model interfaces */ 271 int (*probe)(struct i2c_client *, const struct i2c_device_id *); 272 int (*remove)(struct i2c_client *); 273 274 /* New driver model interface to aid the seamless removal of the 275 * current probe()'s, more commonly unused than used second parameter. 276 */ 277 int (*probe_new)(struct i2c_client *); 278 279 /* driver model interfaces that don't relate to enumeration */ 280 void (*shutdown)(struct i2c_client *); 281 282 /* Alert callback, for example for the SMBus alert protocol. 283 * The format and meaning of the data value depends on the protocol. 284 * For the SMBus alert protocol, there is a single bit of data passed 285 * as the alert response's low bit ("event flag"). 286 * For the SMBus Host Notify protocol, the data corresponds to the 287 * 16-bit payload data reported by the slave device acting as master. 288 */ 289 void (*alert)(struct i2c_client *, enum i2c_alert_protocol protocol, 290 unsigned int data); 291 292 /* a ioctl like command that can be used to perform specific functions 293 * with the device. 294 */ 295 int (*command)(struct i2c_client *client, unsigned int cmd, void *arg); 296 297 struct device_driver driver; 298 const struct i2c_device_id *id_table; 299 300 /* Device detection callback for automatic device creation */ 301 int (*detect)(struct i2c_client *, struct i2c_board_info *); 302 const unsigned short *address_list; 303 struct list_head clients; 304 305 bool disable_i2c_core_irq_mapping; 306 }; 307 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver) 308 309 /** 310 * struct i2c_client - represent an I2C slave device 311 * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address; 312 * I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking 313 * @addr: Address used on the I2C bus connected to the parent adapter. 314 * @name: Indicates the type of the device, usually a chip name that's 315 * generic enough to hide second-sourcing and compatible revisions. 316 * @adapter: manages the bus segment hosting this I2C device 317 * @dev: Driver model device node for the slave. 318 * @irq: indicates the IRQ generated by this device (if any) 319 * @detected: member of an i2c_driver.clients list or i2c-core's 320 * userspace_devices list 321 * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter 322 * calls it to pass on slave events to the slave driver. 323 * 324 * An i2c_client identifies a single device (i.e. chip) connected to an 325 * i2c bus. The behaviour exposed to Linux is defined by the driver 326 * managing the device. 327 */ 328 struct i2c_client { 329 unsigned short flags; /* div., see below */ 330 unsigned short addr; /* chip address - NOTE: 7bit */ 331 /* addresses are stored in the */ 332 /* _LOWER_ 7 bits */ 333 char name[I2C_NAME_SIZE]; 334 struct i2c_adapter *adapter; /* the adapter we sit on */ 335 struct device dev; /* the device structure */ 336 int init_irq; /* irq set at initialization */ 337 int irq; /* irq issued by device */ 338 struct list_head detected; 339 #if IS_ENABLED(CONFIG_I2C_SLAVE) 340 i2c_slave_cb_t slave_cb; /* callback for slave mode */ 341 #endif 342 }; 343 #define to_i2c_client(d) container_of(d, struct i2c_client, dev) 344 345 extern struct i2c_client *i2c_verify_client(struct device *dev); 346 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev); 347 extern const struct i2c_device_id *i2c_match_id(const struct i2c_device_id *id, 348 const struct i2c_client *client); 349 350 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj) 351 { 352 struct device * const dev = container_of(kobj, struct device, kobj); 353 return to_i2c_client(dev); 354 } 355 356 static inline void *i2c_get_clientdata(const struct i2c_client *dev) 357 { 358 return dev_get_drvdata(&dev->dev); 359 } 360 361 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data) 362 { 363 dev_set_drvdata(&dev->dev, data); 364 } 365 366 /* I2C slave support */ 367 368 #if IS_ENABLED(CONFIG_I2C_SLAVE) 369 enum i2c_slave_event { 370 I2C_SLAVE_READ_REQUESTED, 371 I2C_SLAVE_WRITE_REQUESTED, 372 I2C_SLAVE_READ_PROCESSED, 373 I2C_SLAVE_WRITE_RECEIVED, 374 I2C_SLAVE_STOP, 375 }; 376 377 extern int i2c_slave_register(struct i2c_client *client, i2c_slave_cb_t slave_cb); 378 extern int i2c_slave_unregister(struct i2c_client *client); 379 extern bool i2c_detect_slave_mode(struct device *dev); 380 381 static inline int i2c_slave_event(struct i2c_client *client, 382 enum i2c_slave_event event, u8 *val) 383 { 384 return client->slave_cb(client, event, val); 385 } 386 #else 387 static inline bool i2c_detect_slave_mode(struct device *dev) { return false; } 388 #endif 389 390 /** 391 * struct i2c_board_info - template for device creation 392 * @type: chip type, to initialize i2c_client.name 393 * @flags: to initialize i2c_client.flags 394 * @addr: stored in i2c_client.addr 395 * @dev_name: Overrides the default <busnr>-<addr> dev_name if set 396 * @platform_data: stored in i2c_client.dev.platform_data 397 * @of_node: pointer to OpenFirmware device node 398 * @fwnode: device node supplied by the platform firmware 399 * @properties: additional device properties for the device 400 * @resources: resources associated with the device 401 * @num_resources: number of resources in the @resources array 402 * @irq: stored in i2c_client.irq 403 * 404 * I2C doesn't actually support hardware probing, although controllers and 405 * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's 406 * a device at a given address. Drivers commonly need more information than 407 * that, such as chip type, configuration, associated IRQ, and so on. 408 * 409 * i2c_board_info is used to build tables of information listing I2C devices 410 * that are present. This information is used to grow the driver model tree. 411 * For mainboards this is done statically using i2c_register_board_info(); 412 * bus numbers identify adapters that aren't yet available. For add-on boards, 413 * i2c_new_device() does this dynamically with the adapter already known. 414 */ 415 struct i2c_board_info { 416 char type[I2C_NAME_SIZE]; 417 unsigned short flags; 418 unsigned short addr; 419 const char *dev_name; 420 void *platform_data; 421 struct device_node *of_node; 422 struct fwnode_handle *fwnode; 423 const struct property_entry *properties; 424 const struct resource *resources; 425 unsigned int num_resources; 426 int irq; 427 }; 428 429 /** 430 * I2C_BOARD_INFO - macro used to list an i2c device and its address 431 * @dev_type: identifies the device type 432 * @dev_addr: the device's address on the bus. 433 * 434 * This macro initializes essential fields of a struct i2c_board_info, 435 * declaring what has been provided on a particular board. Optional 436 * fields (such as associated irq, or device-specific platform_data) 437 * are provided using conventional syntax. 438 */ 439 #define I2C_BOARD_INFO(dev_type, dev_addr) \ 440 .type = dev_type, .addr = (dev_addr) 441 442 443 #if IS_ENABLED(CONFIG_I2C) 444 /* Add-on boards should register/unregister their devices; e.g. a board 445 * with integrated I2C, a config eeprom, sensors, and a codec that's 446 * used in conjunction with the primary hardware. 447 */ 448 extern struct i2c_client * 449 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info); 450 451 /* If you don't know the exact address of an I2C device, use this variant 452 * instead, which can probe for device presence in a list of possible 453 * addresses. The "probe" callback function is optional. If it is provided, 454 * it must return 1 on successful probe, 0 otherwise. If it is not provided, 455 * a default probing method is used. 456 */ 457 extern struct i2c_client * 458 i2c_new_probed_device(struct i2c_adapter *adap, 459 struct i2c_board_info *info, 460 unsigned short const *addr_list, 461 int (*probe)(struct i2c_adapter *, unsigned short addr)); 462 463 /* Common custom probe functions */ 464 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr); 465 466 /* For devices that use several addresses, use i2c_new_dummy() to make 467 * client handles for the extra addresses. 468 */ 469 extern struct i2c_client * 470 i2c_new_dummy(struct i2c_adapter *adap, u16 address); 471 472 extern struct i2c_client * 473 i2c_new_secondary_device(struct i2c_client *client, 474 const char *name, 475 u16 default_addr); 476 477 extern void i2c_unregister_device(struct i2c_client *); 478 #endif /* I2C */ 479 480 /* Mainboard arch_initcall() code should register all its I2C devices. 481 * This is done at arch_initcall time, before declaring any i2c adapters. 482 * Modules for add-on boards must use other calls. 483 */ 484 #ifdef CONFIG_I2C_BOARDINFO 485 extern int 486 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 487 unsigned n); 488 #else 489 static inline int 490 i2c_register_board_info(int busnum, struct i2c_board_info const *info, 491 unsigned n) 492 { 493 return 0; 494 } 495 #endif /* I2C_BOARDINFO */ 496 497 /** 498 * struct i2c_algorithm - represent I2C transfer method 499 * @master_xfer: Issue a set of i2c transactions to the given I2C adapter 500 * defined by the msgs array, with num messages available to transfer via 501 * the adapter specified by adap. 502 * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this 503 * is not present, then the bus layer will try and convert the SMBus calls 504 * into I2C transfers instead. 505 * @functionality: Return the flags that this algorithm/adapter pair supports 506 * from the I2C_FUNC_* flags. 507 * @reg_slave: Register given client to I2C slave mode of this adapter 508 * @unreg_slave: Unregister given client from I2C slave mode of this adapter 509 * 510 * The following structs are for those who like to implement new bus drivers: 511 * i2c_algorithm is the interface to a class of hardware solutions which can 512 * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584 513 * to name two of the most common. 514 * 515 * The return codes from the @master_xfer field should indicate the type of 516 * error code that occurred during the transfer, as documented in the kernel 517 * Documentation file Documentation/i2c/fault-codes. 518 */ 519 struct i2c_algorithm { 520 /* If an adapter algorithm can't do I2C-level access, set master_xfer 521 to NULL. If an adapter algorithm can do SMBus access, set 522 smbus_xfer. If set to NULL, the SMBus protocol is simulated 523 using common I2C messages */ 524 /* master_xfer should return the number of messages successfully 525 processed, or a negative value on error */ 526 int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs, 527 int num); 528 int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr, 529 unsigned short flags, char read_write, 530 u8 command, int size, union i2c_smbus_data *data); 531 532 /* To determine what the adapter supports */ 533 u32 (*functionality) (struct i2c_adapter *); 534 535 #if IS_ENABLED(CONFIG_I2C_SLAVE) 536 int (*reg_slave)(struct i2c_client *client); 537 int (*unreg_slave)(struct i2c_client *client); 538 #endif 539 }; 540 541 /** 542 * struct i2c_lock_operations - represent I2C locking operations 543 * @lock_bus: Get exclusive access to an I2C bus segment 544 * @trylock_bus: Try to get exclusive access to an I2C bus segment 545 * @unlock_bus: Release exclusive access to an I2C bus segment 546 * 547 * The main operations are wrapped by i2c_lock_bus and i2c_unlock_bus. 548 */ 549 struct i2c_lock_operations { 550 void (*lock_bus)(struct i2c_adapter *, unsigned int flags); 551 int (*trylock_bus)(struct i2c_adapter *, unsigned int flags); 552 void (*unlock_bus)(struct i2c_adapter *, unsigned int flags); 553 }; 554 555 /** 556 * struct i2c_timings - I2C timing information 557 * @bus_freq_hz: the bus frequency in Hz 558 * @scl_rise_ns: time SCL signal takes to rise in ns; t(r) in the I2C specification 559 * @scl_fall_ns: time SCL signal takes to fall in ns; t(f) in the I2C specification 560 * @scl_int_delay_ns: time IP core additionally needs to setup SCL in ns 561 * @sda_fall_ns: time SDA signal takes to fall in ns; t(f) in the I2C specification 562 * @sda_hold_ns: time IP core additionally needs to hold SDA in ns 563 */ 564 struct i2c_timings { 565 u32 bus_freq_hz; 566 u32 scl_rise_ns; 567 u32 scl_fall_ns; 568 u32 scl_int_delay_ns; 569 u32 sda_fall_ns; 570 u32 sda_hold_ns; 571 }; 572 573 /** 574 * struct i2c_bus_recovery_info - I2C bus recovery information 575 * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or 576 * i2c_generic_scl_recovery(). 577 * @get_scl: This gets current value of SCL line. Mandatory for generic SCL 578 * recovery. Populated internally for generic GPIO recovery. 579 * @set_scl: This sets/clears the SCL line. Mandatory for generic SCL recovery. 580 * Populated internally for generic GPIO recovery. 581 * @get_sda: This gets current value of SDA line. This or set_sda() is mandatory 582 * for generic SCL recovery. Populated internally, if sda_gpio is a valid 583 * GPIO, for generic GPIO recovery. 584 * @set_sda: This sets/clears the SDA line. This or get_sda() is mandatory for 585 * generic SCL recovery. Populated internally, if sda_gpio is a valid GPIO, 586 * for generic GPIO recovery. 587 * @get_bus_free: Returns the bus free state as seen from the IP core in case it 588 * has a more complex internal logic than just reading SDA. Optional. 589 * @prepare_recovery: This will be called before starting recovery. Platform may 590 * configure padmux here for SDA/SCL line or something else they want. 591 * @unprepare_recovery: This will be called after completing recovery. Platform 592 * may configure padmux here for SDA/SCL line or something else they want. 593 * @scl_gpiod: gpiod of the SCL line. Only required for GPIO recovery. 594 * @sda_gpiod: gpiod of the SDA line. Only required for GPIO recovery. 595 */ 596 struct i2c_bus_recovery_info { 597 int (*recover_bus)(struct i2c_adapter *adap); 598 599 int (*get_scl)(struct i2c_adapter *adap); 600 void (*set_scl)(struct i2c_adapter *adap, int val); 601 int (*get_sda)(struct i2c_adapter *adap); 602 void (*set_sda)(struct i2c_adapter *adap, int val); 603 int (*get_bus_free)(struct i2c_adapter *adap); 604 605 void (*prepare_recovery)(struct i2c_adapter *adap); 606 void (*unprepare_recovery)(struct i2c_adapter *adap); 607 608 /* gpio recovery */ 609 struct gpio_desc *scl_gpiod; 610 struct gpio_desc *sda_gpiod; 611 }; 612 613 int i2c_recover_bus(struct i2c_adapter *adap); 614 615 /* Generic recovery routines */ 616 int i2c_generic_scl_recovery(struct i2c_adapter *adap); 617 618 /** 619 * struct i2c_adapter_quirks - describe flaws of an i2c adapter 620 * @flags: see I2C_AQ_* for possible flags and read below 621 * @max_num_msgs: maximum number of messages per transfer 622 * @max_write_len: maximum length of a write message 623 * @max_read_len: maximum length of a read message 624 * @max_comb_1st_msg_len: maximum length of the first msg in a combined message 625 * @max_comb_2nd_msg_len: maximum length of the second msg in a combined message 626 * 627 * Note about combined messages: Some I2C controllers can only send one message 628 * per transfer, plus something called combined message or write-then-read. 629 * This is (usually) a small write message followed by a read message and 630 * barely enough to access register based devices like EEPROMs. There is a flag 631 * to support this mode. It implies max_num_msg = 2 and does the length checks 632 * with max_comb_*_len because combined message mode usually has its own 633 * limitations. Because of HW implementations, some controllers can actually do 634 * write-then-anything or other variants. To support that, write-then-read has 635 * been broken out into smaller bits like write-first and read-second which can 636 * be combined as needed. 637 */ 638 639 struct i2c_adapter_quirks { 640 u64 flags; 641 int max_num_msgs; 642 u16 max_write_len; 643 u16 max_read_len; 644 u16 max_comb_1st_msg_len; 645 u16 max_comb_2nd_msg_len; 646 }; 647 648 /* enforce max_num_msgs = 2 and use max_comb_*_len for length checks */ 649 #define I2C_AQ_COMB BIT(0) 650 /* first combined message must be write */ 651 #define I2C_AQ_COMB_WRITE_FIRST BIT(1) 652 /* second combined message must be read */ 653 #define I2C_AQ_COMB_READ_SECOND BIT(2) 654 /* both combined messages must have the same target address */ 655 #define I2C_AQ_COMB_SAME_ADDR BIT(3) 656 /* convenience macro for typical write-then read case */ 657 #define I2C_AQ_COMB_WRITE_THEN_READ (I2C_AQ_COMB | I2C_AQ_COMB_WRITE_FIRST | \ 658 I2C_AQ_COMB_READ_SECOND | I2C_AQ_COMB_SAME_ADDR) 659 /* clock stretching is not supported */ 660 #define I2C_AQ_NO_CLK_STRETCH BIT(4) 661 /* message cannot have length of 0 */ 662 #define I2C_AQ_NO_ZERO_LEN_READ BIT(5) 663 #define I2C_AQ_NO_ZERO_LEN_WRITE BIT(6) 664 #define I2C_AQ_NO_ZERO_LEN (I2C_AQ_NO_ZERO_LEN_READ | I2C_AQ_NO_ZERO_LEN_WRITE) 665 666 /* 667 * i2c_adapter is the structure used to identify a physical i2c bus along 668 * with the access algorithms necessary to access it. 669 */ 670 struct i2c_adapter { 671 struct module *owner; 672 unsigned int class; /* classes to allow probing for */ 673 const struct i2c_algorithm *algo; /* the algorithm to access the bus */ 674 void *algo_data; 675 676 /* data fields that are valid for all devices */ 677 const struct i2c_lock_operations *lock_ops; 678 struct rt_mutex bus_lock; 679 struct rt_mutex mux_lock; 680 681 int timeout; /* in jiffies */ 682 int retries; 683 struct device dev; /* the adapter device */ 684 unsigned long locked_flags; /* owned by the I2C core */ 685 #define I2C_ALF_IS_SUSPENDED 0 686 687 int nr; 688 char name[48]; 689 struct completion dev_released; 690 691 struct mutex userspace_clients_lock; 692 struct list_head userspace_clients; 693 694 struct i2c_bus_recovery_info *bus_recovery_info; 695 const struct i2c_adapter_quirks *quirks; 696 697 struct irq_domain *host_notify_domain; 698 }; 699 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev) 700 701 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev) 702 { 703 return dev_get_drvdata(&dev->dev); 704 } 705 706 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data) 707 { 708 dev_set_drvdata(&dev->dev, data); 709 } 710 711 static inline struct i2c_adapter * 712 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter) 713 { 714 #if IS_ENABLED(CONFIG_I2C_MUX) 715 struct device *parent = adapter->dev.parent; 716 717 if (parent != NULL && parent->type == &i2c_adapter_type) 718 return to_i2c_adapter(parent); 719 else 720 #endif 721 return NULL; 722 } 723 724 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *)); 725 726 /* Adapter locking functions, exported for shared pin cases */ 727 #define I2C_LOCK_ROOT_ADAPTER BIT(0) 728 #define I2C_LOCK_SEGMENT BIT(1) 729 730 /** 731 * i2c_lock_bus - Get exclusive access to an I2C bus segment 732 * @adapter: Target I2C bus segment 733 * @flags: I2C_LOCK_ROOT_ADAPTER locks the root i2c adapter, I2C_LOCK_SEGMENT 734 * locks only this branch in the adapter tree 735 */ 736 static inline void 737 i2c_lock_bus(struct i2c_adapter *adapter, unsigned int flags) 738 { 739 adapter->lock_ops->lock_bus(adapter, flags); 740 } 741 742 /** 743 * i2c_trylock_bus - Try to get exclusive access to an I2C bus segment 744 * @adapter: Target I2C bus segment 745 * @flags: I2C_LOCK_ROOT_ADAPTER tries to locks the root i2c adapter, 746 * I2C_LOCK_SEGMENT tries to lock only this branch in the adapter tree 747 * 748 * Return: true if the I2C bus segment is locked, false otherwise 749 */ 750 static inline int 751 i2c_trylock_bus(struct i2c_adapter *adapter, unsigned int flags) 752 { 753 return adapter->lock_ops->trylock_bus(adapter, flags); 754 } 755 756 /** 757 * i2c_unlock_bus - Release exclusive access to an I2C bus segment 758 * @adapter: Target I2C bus segment 759 * @flags: I2C_LOCK_ROOT_ADAPTER unlocks the root i2c adapter, I2C_LOCK_SEGMENT 760 * unlocks only this branch in the adapter tree 761 */ 762 static inline void 763 i2c_unlock_bus(struct i2c_adapter *adapter, unsigned int flags) 764 { 765 adapter->lock_ops->unlock_bus(adapter, flags); 766 } 767 768 /** 769 * i2c_mark_adapter_suspended - Report suspended state of the adapter to the core 770 * @adap: Adapter to mark as suspended 771 * 772 * When using this helper to mark an adapter as suspended, the core will reject 773 * further transfers to this adapter. The usage of this helper is optional but 774 * recommended for devices having distinct handlers for system suspend and 775 * runtime suspend. More complex devices are free to implement custom solutions 776 * to reject transfers when suspended. 777 */ 778 static inline void i2c_mark_adapter_suspended(struct i2c_adapter *adap) 779 { 780 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 781 set_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 782 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 783 } 784 785 /** 786 * i2c_mark_adapter_resumed - Report resumed state of the adapter to the core 787 * @adap: Adapter to mark as resumed 788 * 789 * When using this helper to mark an adapter as resumed, the core will allow 790 * further transfers to this adapter. See also further notes to 791 * @i2c_mark_adapter_suspended(). 792 */ 793 static inline void i2c_mark_adapter_resumed(struct i2c_adapter *adap) 794 { 795 i2c_lock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 796 clear_bit(I2C_ALF_IS_SUSPENDED, &adap->locked_flags); 797 i2c_unlock_bus(adap, I2C_LOCK_ROOT_ADAPTER); 798 } 799 800 /*flags for the client struct: */ 801 #define I2C_CLIENT_PEC 0x04 /* Use Packet Error Checking */ 802 #define I2C_CLIENT_TEN 0x10 /* we have a ten bit chip address */ 803 /* Must equal I2C_M_TEN below */ 804 #define I2C_CLIENT_SLAVE 0x20 /* we are the slave */ 805 #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ 806 #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ 807 #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ 808 /* Must match I2C_M_STOP|IGNORE_NAK */ 809 810 /* i2c adapter classes (bitmask) */ 811 #define I2C_CLASS_HWMON (1<<0) /* lm_sensors, ... */ 812 #define I2C_CLASS_DDC (1<<3) /* DDC bus on graphics adapters */ 813 #define I2C_CLASS_SPD (1<<7) /* Memory modules */ 814 /* Warn users that the adapter doesn't support classes anymore */ 815 #define I2C_CLASS_DEPRECATED (1<<8) 816 817 /* Internal numbers to terminate lists */ 818 #define I2C_CLIENT_END 0xfffeU 819 820 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */ 821 #define I2C_ADDRS(addr, addrs...) \ 822 ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) 823 824 825 /* ----- functions exported by i2c.o */ 826 827 /* administration... 828 */ 829 #if IS_ENABLED(CONFIG_I2C) 830 extern int i2c_add_adapter(struct i2c_adapter *); 831 extern void i2c_del_adapter(struct i2c_adapter *); 832 extern int i2c_add_numbered_adapter(struct i2c_adapter *); 833 834 extern int i2c_register_driver(struct module *, struct i2c_driver *); 835 extern void i2c_del_driver(struct i2c_driver *); 836 837 /* use a define to avoid include chaining to get THIS_MODULE */ 838 #define i2c_add_driver(driver) \ 839 i2c_register_driver(THIS_MODULE, driver) 840 841 extern struct i2c_client *i2c_use_client(struct i2c_client *client); 842 extern void i2c_release_client(struct i2c_client *client); 843 844 /* call the i2c_client->command() of all attached clients with 845 * the given arguments */ 846 extern void i2c_clients_command(struct i2c_adapter *adap, 847 unsigned int cmd, void *arg); 848 849 extern struct i2c_adapter *i2c_get_adapter(int nr); 850 extern void i2c_put_adapter(struct i2c_adapter *adap); 851 extern unsigned int i2c_adapter_depth(struct i2c_adapter *adapter); 852 853 void i2c_parse_fw_timings(struct device *dev, struct i2c_timings *t, bool use_defaults); 854 855 /* Return the functionality mask */ 856 static inline u32 i2c_get_functionality(struct i2c_adapter *adap) 857 { 858 return adap->algo->functionality(adap); 859 } 860 861 /* Return 1 if adapter supports everything we need, 0 if not. */ 862 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func) 863 { 864 return (func & i2c_get_functionality(adap)) == func; 865 } 866 867 /** 868 * i2c_check_quirks() - Function for checking the quirk flags in an i2c adapter 869 * @adap: i2c adapter 870 * @quirks: quirk flags 871 * 872 * Return: true if the adapter has all the specified quirk flags, false if not 873 */ 874 static inline bool i2c_check_quirks(struct i2c_adapter *adap, u64 quirks) 875 { 876 if (!adap->quirks) 877 return false; 878 return (adap->quirks->flags & quirks) == quirks; 879 } 880 881 /* Return the adapter number for a specific adapter */ 882 static inline int i2c_adapter_id(struct i2c_adapter *adap) 883 { 884 return adap->nr; 885 } 886 887 static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg) 888 { 889 return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0); 890 } 891 892 u8 *i2c_get_dma_safe_msg_buf(struct i2c_msg *msg, unsigned int threshold); 893 void i2c_put_dma_safe_msg_buf(u8 *buf, struct i2c_msg *msg, bool xferred); 894 895 int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr); 896 /** 897 * module_i2c_driver() - Helper macro for registering a modular I2C driver 898 * @__i2c_driver: i2c_driver struct 899 * 900 * Helper macro for I2C drivers which do not do anything special in module 901 * init/exit. This eliminates a lot of boilerplate. Each module may only 902 * use this macro once, and calling it replaces module_init() and module_exit() 903 */ 904 #define module_i2c_driver(__i2c_driver) \ 905 module_driver(__i2c_driver, i2c_add_driver, \ 906 i2c_del_driver) 907 908 /** 909 * builtin_i2c_driver() - Helper macro for registering a builtin I2C driver 910 * @__i2c_driver: i2c_driver struct 911 * 912 * Helper macro for I2C drivers which do not do anything special in their 913 * init. This eliminates a lot of boilerplate. Each driver may only 914 * use this macro once, and calling it replaces device_initcall(). 915 */ 916 #define builtin_i2c_driver(__i2c_driver) \ 917 builtin_driver(__i2c_driver, i2c_add_driver) 918 919 #endif /* I2C */ 920 921 #if IS_ENABLED(CONFIG_OF) 922 /* must call put_device() when done with returned i2c_client device */ 923 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node); 924 925 /* must call put_device() when done with returned i2c_adapter device */ 926 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node); 927 928 /* must call i2c_put_adapter() when done with returned i2c_adapter device */ 929 struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node); 930 931 extern const struct of_device_id 932 *i2c_of_match_device(const struct of_device_id *matches, 933 struct i2c_client *client); 934 935 int of_i2c_get_board_info(struct device *dev, struct device_node *node, 936 struct i2c_board_info *info); 937 938 #else 939 940 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node) 941 { 942 return NULL; 943 } 944 945 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node) 946 { 947 return NULL; 948 } 949 950 static inline struct i2c_adapter *of_get_i2c_adapter_by_node(struct device_node *node) 951 { 952 return NULL; 953 } 954 955 static inline const struct of_device_id 956 *i2c_of_match_device(const struct of_device_id *matches, 957 struct i2c_client *client) 958 { 959 return NULL; 960 } 961 962 static inline int of_i2c_get_board_info(struct device *dev, 963 struct device_node *node, 964 struct i2c_board_info *info) 965 { 966 return -ENOTSUPP; 967 } 968 969 #endif /* CONFIG_OF */ 970 971 struct acpi_resource; 972 struct acpi_resource_i2c_serialbus; 973 974 #if IS_ENABLED(CONFIG_ACPI) 975 bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 976 struct acpi_resource_i2c_serialbus **i2c); 977 u32 i2c_acpi_find_bus_speed(struct device *dev); 978 struct i2c_client *i2c_acpi_new_device(struct device *dev, int index, 979 struct i2c_board_info *info); 980 #else 981 static inline bool i2c_acpi_get_i2c_resource(struct acpi_resource *ares, 982 struct acpi_resource_i2c_serialbus **i2c) 983 { 984 return false; 985 } 986 static inline u32 i2c_acpi_find_bus_speed(struct device *dev) 987 { 988 return 0; 989 } 990 static inline struct i2c_client *i2c_acpi_new_device(struct device *dev, 991 int index, struct i2c_board_info *info) 992 { 993 return NULL; 994 } 995 #endif /* CONFIG_ACPI */ 996 997 #endif /* _LINUX_I2C_H */ 998