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