~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/i2c.h

Version: ~ [ linux-5.10-rc5 ] ~ [ linux-5.9.10 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.79 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.159 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.208 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.245 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.245 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.85 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 50 struct module;
 51 
 52 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
 53 /*
 54  * The master routines are the ones normally used to transmit data to devices
 55  * on a bus (or read from them). Apart from two basic transfer functions to
 56  * transmit one message at a time, a more complex version can be used to
 57  * transmit an arbitrary number of messages without interruption.
 58  * @count must be be less than 64k since msg.len is u16.
 59  */
 60 extern int i2c_master_send(const struct i2c_client *client, const char *buf,
 61                            int count);
 62 extern int i2c_master_recv(const struct i2c_client *client, char *buf,
 63                            int count);
 64 
 65 /* Transfer num messages.
 66  */
 67 extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 68                         int num);
 69 /* Unlocked flavor */
 70 extern int __i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
 71                           int num);
 72 
 73 /* This is the very generalized SMBus access routine. You probably do not
 74    want to use this, though; one of the functions below may be much easier,
 75    and probably just as fast.
 76    Note that we use i2c_adapter here, because you do not need a specific
 77    smbus adapter to call this function. */
 78 extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
 79                           unsigned short flags, char read_write, u8 command,
 80                           int size, union i2c_smbus_data *data);
 81 
 82 /* Now follow the 'nice' access routines. These also document the calling
 83    conventions of i2c_smbus_xfer. */
 84 
 85 extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
 86 extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
 87 extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
 88                                     u8 command);
 89 extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
 90                                      u8 command, u8 value);
 91 extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
 92                                     u8 command);
 93 extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
 94                                      u8 command, u16 value);
 95 
 96 static inline s32
 97 i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
 98 {
 99         s32 value = i2c_smbus_read_word_data(client, command);
100 
101         return (value < 0) ? value : swab16(value);
102 }
103 
104 static inline s32
105 i2c_smbus_write_word_swapped(const struct i2c_client *client,
106                              u8 command, u16 value)
107 {
108         return i2c_smbus_write_word_data(client, command, swab16(value));
109 }
110 
111 /* Returns the number of read bytes */
112 extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
113                                      u8 command, u8 *values);
114 extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
115                                       u8 command, u8 length, const u8 *values);
116 /* Returns the number of read bytes */
117 extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
118                                          u8 command, u8 length, u8 *values);
119 extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
120                                           u8 command, u8 length,
121                                           const u8 *values);
122 #endif /* I2C */
123 
124 /**
125  * struct i2c_driver - represent an I2C device driver
126  * @class: What kind of i2c device we instantiate (for detect)
127  * @attach_adapter: Callback for bus addition (deprecated)
128  * @probe: Callback for device binding
129  * @remove: Callback for device unbinding
130  * @shutdown: Callback for device shutdown
131  * @suspend: Callback for device suspend
132  * @resume: Callback for device resume
133  * @alert: Alert callback, for example for the SMBus alert protocol
134  * @command: Callback for bus-wide signaling (optional)
135  * @driver: Device driver model driver
136  * @id_table: List of I2C devices supported by this driver
137  * @detect: Callback for device detection
138  * @address_list: The I2C addresses to probe (for detect)
139  * @clients: List of detected clients we created (for i2c-core use only)
140  *
141  * The driver.owner field should be set to the module owner of this driver.
142  * The driver.name field should be set to the name of this driver.
143  *
144  * For automatic device detection, both @detect and @address_list must
145  * be defined. @class should also be set, otherwise only devices forced
146  * with module parameters will be created. The detect function must
147  * fill at least the name field of the i2c_board_info structure it is
148  * handed upon successful detection, and possibly also the flags field.
149  *
150  * If @detect is missing, the driver will still work fine for enumerated
151  * devices. Detected devices simply won't be supported. This is expected
152  * for the many I2C/SMBus devices which can't be detected reliably, and
153  * the ones which can always be enumerated in practice.
154  *
155  * The i2c_client structure which is handed to the @detect callback is
156  * not a real i2c_client. It is initialized just enough so that you can
157  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
158  * else with it. In particular, calling dev_dbg and friends on it is
159  * not allowed.
160  */
161 struct i2c_driver {
162         unsigned int class;
163 
164         /* Notifies the driver that a new bus has appeared. You should avoid
165          * using this, it will be removed in a near future.
166          */
167         int (*attach_adapter)(struct i2c_adapter *) __deprecated;
168 
169         /* Standard driver model interfaces */
170         int (*probe)(struct i2c_client *, const struct i2c_device_id *);
171         int (*remove)(struct i2c_client *);
172 
173         /* driver model interfaces that don't relate to enumeration  */
174         void (*shutdown)(struct i2c_client *);
175         int (*suspend)(struct i2c_client *, pm_message_t mesg);
176         int (*resume)(struct i2c_client *);
177 
178         /* Alert callback, for example for the SMBus alert protocol.
179          * The format and meaning of the data value depends on the protocol.
180          * For the SMBus alert protocol, there is a single bit of data passed
181          * as the alert response's low bit ("event flag").
182          */
183         void (*alert)(struct i2c_client *, unsigned int data);
184 
185         /* a ioctl like command that can be used to perform specific functions
186          * with the device.
187          */
188         int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
189 
190         struct device_driver driver;
191         const struct i2c_device_id *id_table;
192 
193         /* Device detection callback for automatic device creation */
194         int (*detect)(struct i2c_client *, struct i2c_board_info *);
195         const unsigned short *address_list;
196         struct list_head clients;
197 };
198 #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
199 
200 /**
201  * struct i2c_client - represent an I2C slave device
202  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
203  *      I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
204  * @addr: Address used on the I2C bus connected to the parent adapter.
205  * @name: Indicates the type of the device, usually a chip name that's
206  *      generic enough to hide second-sourcing and compatible revisions.
207  * @adapter: manages the bus segment hosting this I2C device
208  * @dev: Driver model device node for the slave.
209  * @irq: indicates the IRQ generated by this device (if any)
210  * @detected: member of an i2c_driver.clients list or i2c-core's
211  *      userspace_devices list
212  *
213  * An i2c_client identifies a single device (i.e. chip) connected to an
214  * i2c bus. The behaviour exposed to Linux is defined by the driver
215  * managing the device.
216  */
217 struct i2c_client {
218         unsigned short flags;           /* div., see below              */
219         unsigned short addr;            /* chip address - NOTE: 7bit    */
220                                         /* addresses are stored in the  */
221                                         /* _LOWER_ 7 bits               */
222         char name[I2C_NAME_SIZE];
223         struct i2c_adapter *adapter;    /* the adapter we sit on        */
224         struct device dev;              /* the device structure         */
225         int irq;                        /* irq issued by device         */
226         struct list_head detected;
227 };
228 #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
229 
230 extern struct i2c_client *i2c_verify_client(struct device *dev);
231 extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
232 
233 static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
234 {
235         struct device * const dev = container_of(kobj, struct device, kobj);
236         return to_i2c_client(dev);
237 }
238 
239 static inline void *i2c_get_clientdata(const struct i2c_client *dev)
240 {
241         return dev_get_drvdata(&dev->dev);
242 }
243 
244 static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
245 {
246         dev_set_drvdata(&dev->dev, data);
247 }
248 
249 /**
250  * struct i2c_board_info - template for device creation
251  * @type: chip type, to initialize i2c_client.name
252  * @flags: to initialize i2c_client.flags
253  * @addr: stored in i2c_client.addr
254  * @platform_data: stored in i2c_client.dev.platform_data
255  * @archdata: copied into i2c_client.dev.archdata
256  * @of_node: pointer to OpenFirmware device node
257  * @acpi_node: ACPI device node
258  * @irq: stored in i2c_client.irq
259  *
260  * I2C doesn't actually support hardware probing, although controllers and
261  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
262  * a device at a given address.  Drivers commonly need more information than
263  * that, such as chip type, configuration, associated IRQ, and so on.
264  *
265  * i2c_board_info is used to build tables of information listing I2C devices
266  * that are present.  This information is used to grow the driver model tree.
267  * For mainboards this is done statically using i2c_register_board_info();
268  * bus numbers identify adapters that aren't yet available.  For add-on boards,
269  * i2c_new_device() does this dynamically with the adapter already known.
270  */
271 struct i2c_board_info {
272         char            type[I2C_NAME_SIZE];
273         unsigned short  flags;
274         unsigned short  addr;
275         void            *platform_data;
276         struct dev_archdata     *archdata;
277         struct device_node *of_node;
278         struct acpi_dev_node acpi_node;
279         int             irq;
280 };
281 
282 /**
283  * I2C_BOARD_INFO - macro used to list an i2c device and its address
284  * @dev_type: identifies the device type
285  * @dev_addr: the device's address on the bus.
286  *
287  * This macro initializes essential fields of a struct i2c_board_info,
288  * declaring what has been provided on a particular board.  Optional
289  * fields (such as associated irq, or device-specific platform_data)
290  * are provided using conventional syntax.
291  */
292 #define I2C_BOARD_INFO(dev_type, dev_addr) \
293         .type = dev_type, .addr = (dev_addr)
294 
295 
296 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
297 /* Add-on boards should register/unregister their devices; e.g. a board
298  * with integrated I2C, a config eeprom, sensors, and a codec that's
299  * used in conjunction with the primary hardware.
300  */
301 extern struct i2c_client *
302 i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);
303 
304 /* If you don't know the exact address of an I2C device, use this variant
305  * instead, which can probe for device presence in a list of possible
306  * addresses. The "probe" callback function is optional. If it is provided,
307  * it must return 1 on successful probe, 0 otherwise. If it is not provided,
308  * a default probing method is used.
309  */
310 extern struct i2c_client *
311 i2c_new_probed_device(struct i2c_adapter *adap,
312                       struct i2c_board_info *info,
313                       unsigned short const *addr_list,
314                       int (*probe)(struct i2c_adapter *, unsigned short addr));
315 
316 /* Common custom probe functions */
317 extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);
318 
319 /* For devices that use several addresses, use i2c_new_dummy() to make
320  * client handles for the extra addresses.
321  */
322 extern struct i2c_client *
323 i2c_new_dummy(struct i2c_adapter *adap, u16 address);
324 
325 extern void i2c_unregister_device(struct i2c_client *);
326 #endif /* I2C */
327 
328 /* Mainboard arch_initcall() code should register all its I2C devices.
329  * This is done at arch_initcall time, before declaring any i2c adapters.
330  * Modules for add-on boards must use other calls.
331  */
332 #ifdef CONFIG_I2C_BOARDINFO
333 extern int
334 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
335                         unsigned n);
336 #else
337 static inline int
338 i2c_register_board_info(int busnum, struct i2c_board_info const *info,
339                         unsigned n)
340 {
341         return 0;
342 }
343 #endif /* I2C_BOARDINFO */
344 
345 /**
346  * struct i2c_algorithm - represent I2C transfer method
347  * @master_xfer: Issue a set of i2c transactions to the given I2C adapter
348  *   defined by the msgs array, with num messages available to transfer via
349  *   the adapter specified by adap.
350  * @smbus_xfer: Issue smbus transactions to the given I2C adapter. If this
351  *   is not present, then the bus layer will try and convert the SMBus calls
352  *   into I2C transfers instead.
353  * @functionality: Return the flags that this algorithm/adapter pair supports
354  *   from the I2C_FUNC_* flags.
355  *
356  * The following structs are for those who like to implement new bus drivers:
357  * i2c_algorithm is the interface to a class of hardware solutions which can
358  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
359  * to name two of the most common.
360  *
361  * The return codes from the @master_xfer field should indicate the type of
362  * error code that occured during the transfer, as documented in the kernel
363  * Documentation file Documentation/i2c/fault-codes.
364  */
365 struct i2c_algorithm {
366         /* If an adapter algorithm can't do I2C-level access, set master_xfer
367            to NULL. If an adapter algorithm can do SMBus access, set
368            smbus_xfer. If set to NULL, the SMBus protocol is simulated
369            using common I2C messages */
370         /* master_xfer should return the number of messages successfully
371            processed, or a negative value on error */
372         int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
373                            int num);
374         int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
375                            unsigned short flags, char read_write,
376                            u8 command, int size, union i2c_smbus_data *data);
377 
378         /* To determine what the adapter supports */
379         u32 (*functionality) (struct i2c_adapter *);
380 };
381 
382 /**
383  * struct i2c_bus_recovery_info - I2C bus recovery information
384  * @recover_bus: Recover routine. Either pass driver's recover_bus() routine, or
385  *      i2c_generic_scl_recovery() or i2c_generic_gpio_recovery().
386  * @get_scl: This gets current value of SCL line. Mandatory for generic SCL
387  *      recovery. Used internally for generic GPIO recovery.
388  * @set_scl: This sets/clears SCL line. Mandatory for generic SCL recovery. Used
389  *      internally for generic GPIO recovery.
390  * @get_sda: This gets current value of SDA line. Optional for generic SCL
391  *      recovery. Used internally, if sda_gpio is a valid GPIO, for generic GPIO
392  *      recovery.
393  * @prepare_recovery: This will be called before starting recovery. Platform may
394  *      configure padmux here for SDA/SCL line or something else they want.
395  * @unprepare_recovery: This will be called after completing recovery. Platform
396  *      may configure padmux here for SDA/SCL line or something else they want.
397  * @scl_gpio: gpio number of the SCL line. Only required for GPIO recovery.
398  * @sda_gpio: gpio number of the SDA line. Only required for GPIO recovery.
399  */
400 struct i2c_bus_recovery_info {
401         int (*recover_bus)(struct i2c_adapter *);
402 
403         int (*get_scl)(struct i2c_adapter *);
404         void (*set_scl)(struct i2c_adapter *, int val);
405         int (*get_sda)(struct i2c_adapter *);
406 
407         void (*prepare_recovery)(struct i2c_bus_recovery_info *bri);
408         void (*unprepare_recovery)(struct i2c_bus_recovery_info *bri);
409 
410         /* gpio recovery */
411         int scl_gpio;
412         int sda_gpio;
413 };
414 
415 int i2c_recover_bus(struct i2c_adapter *adap);
416 
417 /* Generic recovery routines */
418 int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
419 int i2c_generic_scl_recovery(struct i2c_adapter *adap);
420 
421 /*
422  * i2c_adapter is the structure used to identify a physical i2c bus along
423  * with the access algorithms necessary to access it.
424  */
425 struct i2c_adapter {
426         struct module *owner;
427         unsigned int class;               /* classes to allow probing for */
428         const struct i2c_algorithm *algo; /* the algorithm to access the bus */
429         void *algo_data;
430 
431         /* data fields that are valid for all devices   */
432         struct rt_mutex bus_lock;
433 
434         int timeout;                    /* in jiffies */
435         int retries;
436         struct device dev;              /* the adapter device */
437 
438         int nr;
439         char name[48];
440         struct completion dev_released;
441 
442         struct mutex userspace_clients_lock;
443         struct list_head userspace_clients;
444 
445         struct i2c_bus_recovery_info *bus_recovery_info;
446 };
447 #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
448 
449 static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
450 {
451         return dev_get_drvdata(&dev->dev);
452 }
453 
454 static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
455 {
456         dev_set_drvdata(&dev->dev, data);
457 }
458 
459 static inline struct i2c_adapter *
460 i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
461 {
462 #if IS_ENABLED(CONFIG_I2C_MUX)
463         struct device *parent = adapter->dev.parent;
464 
465         if (parent != NULL && parent->type == &i2c_adapter_type)
466                 return to_i2c_adapter(parent);
467         else
468 #endif
469                 return NULL;
470 }
471 
472 int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));
473 
474 /* Adapter locking functions, exported for shared pin cases */
475 void i2c_lock_adapter(struct i2c_adapter *);
476 void i2c_unlock_adapter(struct i2c_adapter *);
477 
478 /*flags for the client struct: */
479 #define I2C_CLIENT_PEC  0x04            /* Use Packet Error Checking */
480 #define I2C_CLIENT_TEN  0x10            /* we have a ten bit chip address */
481                                         /* Must equal I2C_M_TEN below */
482 #define I2C_CLIENT_WAKE 0x80            /* for board_info; true iff can wake */
483 #define I2C_CLIENT_SCCB 0x9000          /* Use Omnivision SCCB protocol */
484                                         /* Must match I2C_M_STOP|IGNORE_NAK */
485 
486 /* i2c adapter classes (bitmask) */
487 #define I2C_CLASS_HWMON         (1<<0)  /* lm_sensors, ... */
488 #define I2C_CLASS_DDC           (1<<3)  /* DDC bus on graphics adapters */
489 #define I2C_CLASS_SPD           (1<<7)  /* Memory modules */
490 #define I2C_CLASS_DEPRECATED    (1<<8)  /* Warn users that adapter will stop using classes */
491 
492 /* Internal numbers to terminate lists */
493 #define I2C_CLIENT_END          0xfffeU
494 
495 /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
496 #define I2C_ADDRS(addr, addrs...) \
497         ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
498 
499 
500 /* ----- functions exported by i2c.o */
501 
502 /* administration...
503  */
504 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
505 extern int i2c_add_adapter(struct i2c_adapter *);
506 extern void i2c_del_adapter(struct i2c_adapter *);
507 extern int i2c_add_numbered_adapter(struct i2c_adapter *);
508 
509 extern int i2c_register_driver(struct module *, struct i2c_driver *);
510 extern void i2c_del_driver(struct i2c_driver *);
511 
512 /* use a define to avoid include chaining to get THIS_MODULE */
513 #define i2c_add_driver(driver) \
514         i2c_register_driver(THIS_MODULE, driver)
515 
516 extern struct i2c_client *i2c_use_client(struct i2c_client *client);
517 extern void i2c_release_client(struct i2c_client *client);
518 
519 /* call the i2c_client->command() of all attached clients with
520  * the given arguments */
521 extern void i2c_clients_command(struct i2c_adapter *adap,
522                                 unsigned int cmd, void *arg);
523 
524 extern struct i2c_adapter *i2c_get_adapter(int nr);
525 extern void i2c_put_adapter(struct i2c_adapter *adap);
526 
527 
528 /* Return the functionality mask */
529 static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
530 {
531         return adap->algo->functionality(adap);
532 }
533 
534 /* Return 1 if adapter supports everything we need, 0 if not. */
535 static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
536 {
537         return (func & i2c_get_functionality(adap)) == func;
538 }
539 
540 /* Return the adapter number for a specific adapter */
541 static inline int i2c_adapter_id(struct i2c_adapter *adap)
542 {
543         return adap->nr;
544 }
545 
546 /**
547  * module_i2c_driver() - Helper macro for registering a I2C driver
548  * @__i2c_driver: i2c_driver struct
549  *
550  * Helper macro for I2C drivers which do not do anything special in module
551  * init/exit. This eliminates a lot of boilerplate. Each module may only
552  * use this macro once, and calling it replaces module_init() and module_exit()
553  */
554 #define module_i2c_driver(__i2c_driver) \
555         module_driver(__i2c_driver, i2c_add_driver, \
556                         i2c_del_driver)
557 
558 #endif /* I2C */
559 
560 #if IS_ENABLED(CONFIG_OF)
561 /* must call put_device() when done with returned i2c_client device */
562 extern struct i2c_client *of_find_i2c_device_by_node(struct device_node *node);
563 
564 /* must call put_device() when done with returned i2c_adapter device */
565 extern struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node);
566 
567 #else
568 
569 static inline struct i2c_client *of_find_i2c_device_by_node(struct device_node *node)
570 {
571         return NULL;
572 }
573 
574 static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node *node)
575 {
576         return NULL;
577 }
578 #endif /* CONFIG_OF */
579 
580 #endif /* _LINUX_I2C_H */
581 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp