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  1. /* ------------------------------------------------------------------------- */
  2. /*                                                                           */
  3. /* i2c.h - definitions for the i2c-bus interface                             */
  4. /*                                                                           */
  5. /* ------------------------------------------------------------------------- */
  6. /*   Copyright (C) 1995-2000 Simon G. Vogl
  7.  
  8.     This program is free software; you can redistribute it and/or modify
  9.     it under the terms of the GNU General Public License as published by
  10.     the Free Software Foundation; either version 2 of the License, or
  11.     (at your option) any later version.
  12.  
  13.     This program is distributed in the hope that it will be useful,
  14.     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15.     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16.     GNU General Public License for more details.
  17.  
  18.     You should have received a copy of the GNU General Public License
  19.     along with this program; if not, write to the Free Software
  20.     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.                */
  21. /* ------------------------------------------------------------------------- */
  22.  
  23. /* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and
  24.    Frodo Looijaard <frodol@dds.nl> */
  25.  
  26. #ifndef _LINUX_I2C_H
  27. #define _LINUX_I2C_H
  28.  
  29. #include <linux/types.h>
  30. #ifdef __KERNEL__
  31. #include <linux/module.h>
  32. #include <linux/i2c-id.h>
  33. #include <linux/mod_devicetable.h>
  34.  
  35.  
  36. /* --- General options ------------------------------------------------ */
  37.  
  38. struct i2c_msg;
  39. struct i2c_algorithm;
  40. struct i2c_adapter;
  41. struct i2c_client;
  42. struct i2c_driver;
  43. union i2c_smbus_data;
  44. struct i2c_board_info;
  45.  
  46.  
  47. /* Transfer num messages.
  48.  */
  49. extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  50.                         int num);
  51.  
  52. /**
  53.  * struct i2c_driver - represent an I2C device driver
  54.  * @class: What kind of i2c device we instantiate (for detect)
  55.  * @attach_adapter: Callback for bus addition (deprecated)
  56.  * @detach_adapter: Callback for bus removal (deprecated)
  57.  * @probe: Callback for device binding
  58.  * @remove: Callback for device unbinding
  59.  * @shutdown: Callback for device shutdown
  60.  * @suspend: Callback for device suspend
  61.  * @resume: Callback for device resume
  62.  * @alert: Alert callback, for example for the SMBus alert protocol
  63.  * @command: Callback for bus-wide signaling (optional)
  64.  * @driver: Device driver model driver
  65.  * @id_table: List of I2C devices supported by this driver
  66.  * @detect: Callback for device detection
  67.  * @address_list: The I2C addresses to probe (for detect)
  68.  * @clients: List of detected clients we created (for i2c-core use only)
  69.  *
  70.  * The driver.owner field should be set to the module owner of this driver.
  71.  * The driver.name field should be set to the name of this driver.
  72.  *
  73.  * For automatic device detection, both @detect and @address_data must
  74.  * be defined. @class should also be set, otherwise only devices forced
  75.  * with module parameters will be created. The detect function must
  76.  * fill at least the name field of the i2c_board_info structure it is
  77.  * handed upon successful detection, and possibly also the flags field.
  78.  *
  79.  * If @detect is missing, the driver will still work fine for enumerated
  80.  * devices. Detected devices simply won't be supported. This is expected
  81.  * for the many I2C/SMBus devices which can't be detected reliably, and
  82.  * the ones which can always be enumerated in practice.
  83.  *
  84.  * The i2c_client structure which is handed to the @detect callback is
  85.  * not a real i2c_client. It is initialized just enough so that you can
  86.  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
  87.  * else with it. In particular, calling dev_dbg and friends on it is
  88.  * not allowed.
  89.  */
  90. struct i2c_driver {
  91.         unsigned int class;
  92.  
  93.         /* Notifies the driver that a new bus has appeared or is about to be
  94.          * removed. You should avoid using this, it will be removed in a
  95.          * near future.
  96.          */
  97.         int (*attach_adapter)(struct i2c_adapter *) __deprecated;
  98.         int (*detach_adapter)(struct i2c_adapter *) __deprecated;
  99.  
  100.         /* Standard driver model interfaces */
  101.         int (*probe)(struct i2c_client *, const struct i2c_device_id *);
  102.         int (*remove)(struct i2c_client *);
  103.  
  104.         /* driver model interfaces that don't relate to enumeration  */
  105.         void (*shutdown)(struct i2c_client *);
  106. //      int (*suspend)(struct i2c_client *, pm_message_t mesg);
  107.         int (*resume)(struct i2c_client *);
  108.  
  109.         /* Alert callback, for example for the SMBus alert protocol.
  110.          * The format and meaning of the data value depends on the protocol.
  111.          * For the SMBus alert protocol, there is a single bit of data passed
  112.          * as the alert response's low bit ("event flag").
  113.          */
  114.         void (*alert)(struct i2c_client *, unsigned int data);
  115.  
  116.         /* a ioctl like command that can be used to perform specific functions
  117.          * with the device.
  118.          */
  119.         int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
  120.  
  121. //      struct device_driver driver;
  122.         const struct i2c_device_id *id_table;
  123.  
  124.         /* Device detection callback for automatic device creation */
  125. //      int (*detect)(struct i2c_client *, struct i2c_board_info *);
  126.         const unsigned short *address_list;
  127.         struct list_head clients;
  128. };
  129. #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
  130.  
  131. /**
  132.  * struct i2c_client - represent an I2C slave device
  133.  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
  134.  *      I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
  135.  * @addr: Address used on the I2C bus connected to the parent adapter.
  136.  * @name: Indicates the type of the device, usually a chip name that's
  137.  *      generic enough to hide second-sourcing and compatible revisions.
  138.  * @adapter: manages the bus segment hosting this I2C device
  139.  * @driver: device's driver, hence pointer to access routines
  140.  * @dev: Driver model device node for the slave.
  141.  * @irq: indicates the IRQ generated by this device (if any)
  142.  * @detected: member of an i2c_driver.clients list or i2c-core's
  143.  *      userspace_devices list
  144.  *
  145.  * An i2c_client identifies a single device (i.e. chip) connected to an
  146.  * i2c bus. The behaviour exposed to Linux is defined by the driver
  147.  * managing the device.
  148.  */
  149. struct i2c_client {
  150.         unsigned short flags;           /* div., see below              */
  151.         unsigned short addr;            /* chip address - NOTE: 7bit    */
  152.                                         /* addresses are stored in the  */
  153.                                         /* _LOWER_ 7 bits               */
  154.         char name[I2C_NAME_SIZE];
  155.         struct i2c_adapter *adapter;    /* the adapter we sit on        */
  156.     struct i2c_driver *driver;      /* and our access routines      */
  157.         struct device dev;              /* the device structure         */
  158.         int irq;                        /* irq issued by device         */
  159.         struct list_head detected;
  160. };
  161. #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
  162.  
  163. extern struct i2c_client *i2c_verify_client(struct device *dev);
  164.  
  165. /**
  166.  * struct i2c_board_info - template for device creation
  167.  * @type: chip type, to initialize i2c_client.name
  168.  * @flags: to initialize i2c_client.flags
  169.  * @addr: stored in i2c_client.addr
  170.  * @platform_data: stored in i2c_client.dev.platform_data
  171.  * @archdata: copied into i2c_client.dev.archdata
  172.  * @of_node: pointer to OpenFirmware device node
  173.  * @irq: stored in i2c_client.irq
  174.  *
  175.  * I2C doesn't actually support hardware probing, although controllers and
  176.  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
  177.  * a device at a given address.  Drivers commonly need more information than
  178.  * that, such as chip type, configuration, associated IRQ, and so on.
  179.  *
  180.  * i2c_board_info is used to build tables of information listing I2C devices
  181.  * that are present.  This information is used to grow the driver model tree.
  182.  * For mainboards this is done statically using i2c_register_board_info();
  183.  * bus numbers identify adapters that aren't yet available.  For add-on boards,
  184.  * i2c_new_device() does this dynamically with the adapter already known.
  185.  */
  186. struct i2c_board_info {
  187.         char            type[I2C_NAME_SIZE];
  188.         unsigned short  flags;
  189.         unsigned short  addr;
  190.         void            *platform_data;
  191.         struct dev_archdata     *archdata;
  192. #ifdef CONFIG_OF
  193.         struct device_node *of_node;
  194. #endif
  195.         int             irq;
  196. };
  197.  
  198. /**
  199.  * I2C_BOARD_INFO - macro used to list an i2c device and its address
  200.  * @dev_type: identifies the device type
  201.  * @dev_addr: the device's address on the bus.
  202.  *
  203.  * This macro initializes essential fields of a struct i2c_board_info,
  204.  * declaring what has been provided on a particular board.  Optional
  205.  * fields (such as associated irq, or device-specific platform_data)
  206.  * are provided using conventional syntax.
  207.  */
  208. #define I2C_BOARD_INFO(dev_type, dev_addr) \
  209.         .type = dev_type, .addr = (dev_addr)
  210. /*
  211.  * The following structs are for those who like to implement new bus drivers:
  212.  * i2c_algorithm is the interface to a class of hardware solutions which can
  213.  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  214.  * to name two of the most common.
  215.  */
  216. struct i2c_algorithm {
  217.         /* If an adapter algorithm can't do I2C-level access, set master_xfer
  218.            to NULL. If an adapter algorithm can do SMBus access, set
  219.            smbus_xfer. If set to NULL, the SMBus protocol is simulated
  220.            using common I2C messages */
  221.         /* master_xfer should return the number of messages successfully
  222.            processed, or a negative value on error */
  223.         int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
  224.                            int num);
  225.         int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
  226.                            unsigned short flags, char read_write,
  227.                            u8 command, int size, union i2c_smbus_data *data);
  228.  
  229.         /* To determine what the adapter supports */
  230.         u32 (*functionality) (struct i2c_adapter *);
  231. };
  232.  
  233. /*
  234.  * i2c_adapter is the structure used to identify a physical i2c bus along
  235.  * with the access algorithms necessary to access it.
  236.  */
  237. struct i2c_adapter {
  238.         struct module *owner;
  239.         unsigned int class;               /* classes to allow probing for */
  240.         const struct i2c_algorithm *algo; /* the algorithm to access the bus */
  241.         void *algo_data;
  242.  
  243.         /* data fields that are valid for all devices   */
  244. //      struct rt_mutex bus_lock;
  245.  
  246.         int timeout;                    /* in jiffies */
  247.     int retries;
  248.     struct device dev;      /* the adapter device */
  249.  
  250.     int nr;
  251.     char name[48];
  252. };
  253. #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
  254.  
  255. static inline void *i2c_get_adapdata(struct i2c_adapter *dev)
  256. {
  257.         return dev_get_drvdata(&dev->dev);
  258. }
  259.  
  260. static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
  261. {
  262.         dev_set_drvdata(&dev->dev, data);
  263. }
  264.  
  265. /* Adapter locking functions, exported for shared pin cases */
  266. void i2c_lock_adapter(struct i2c_adapter *);
  267. void i2c_unlock_adapter(struct i2c_adapter *);
  268.  
  269. /*flags for the client struct: */
  270. #define I2C_CLIENT_PEC  0x04            /* Use Packet Error Checking */
  271. #define I2C_CLIENT_TEN  0x10            /* we have a ten bit chip address */
  272.                                         /* Must equal I2C_M_TEN below */
  273. #define I2C_CLIENT_WAKE 0x80            /* for board_info; true iff can wake */
  274.  
  275. /* i2c adapter classes (bitmask) */
  276. #define I2C_CLASS_HWMON         (1<<0)  /* lm_sensors, ... */
  277. #define I2C_CLASS_DDC           (1<<3)  /* DDC bus on graphics adapters */
  278. #define I2C_CLASS_SPD           (1<<7)  /* Memory modules */
  279.  
  280. /* Internal numbers to terminate lists */
  281. #define I2C_CLIENT_END          0xfffeU
  282.  
  283. /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
  284. #define I2C_ADDRS(addr, addrs...) \
  285.         ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
  286.  
  287.  
  288. #endif /* __KERNEL__ */
  289.  
  290. /**
  291.  * struct i2c_msg - an I2C transaction segment beginning with START
  292.  * @addr: Slave address, either seven or ten bits.  When this is a ten
  293.  *      bit address, I2C_M_TEN must be set in @flags and the adapter
  294.  *      must support I2C_FUNC_10BIT_ADDR.
  295.  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
  296.  *      provided unless the adapter exported the relevant I2C_FUNC_*
  297.  *      flags through i2c_check_functionality().
  298.  * @len: Number of data bytes in @buf being read from or written to the
  299.  *      I2C slave address.  For read transactions where I2C_M_RECV_LEN
  300.  *      is set, the caller guarantees that this buffer can hold up to
  301.  *      32 bytes in addition to the initial length byte sent by the
  302.  *      slave (plus, if used, the SMBus PEC); and this value will be
  303.  *      incremented by the number of block data bytes received.
  304.  * @buf: The buffer into which data is read, or from which it's written.
  305.  *
  306.  * An i2c_msg is the low level representation of one segment of an I2C
  307.  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
  308.  * to userspace from i2c-dev, and to I2C adapter drivers through the
  309.  * @i2c_adapter.@master_xfer() method.
  310.  *
  311.  * Except when I2C "protocol mangling" is used, all I2C adapters implement
  312.  * the standard rules for I2C transactions.  Each transaction begins with a
  313.  * START.  That is followed by the slave address, and a bit encoding read
  314.  * versus write.  Then follow all the data bytes, possibly including a byte
  315.  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
  316.  * bytes have been transferred and ACKed.  If this is the last message in a
  317.  * group, it is followed by a STOP.  Otherwise it is followed by the next
  318.  * @i2c_msg transaction segment, beginning with a (repeated) START.
  319.  *
  320.  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
  321.  * passing certain @flags may have changed those standard protocol behaviors.
  322.  * Those flags are only for use with broken/nonconforming slaves, and with
  323.  * adapters which are known to support the specific mangling options they
  324.  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
  325.  */
  326. struct i2c_msg {
  327.         __u16 addr;     /* slave address                        */
  328.         __u16 flags;
  329. #define I2C_M_TEN               0x0010  /* this is a ten bit chip address */
  330. #define I2C_M_RD                0x0001  /* read data, from slave to master */
  331. #define I2C_M_NOSTART           0x4000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  332. #define I2C_M_REV_DIR_ADDR      0x2000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  333. #define I2C_M_IGNORE_NAK        0x1000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  334. #define I2C_M_NO_RD_ACK         0x0800  /* if I2C_FUNC_PROTOCOL_MANGLING */
  335. #define I2C_M_RECV_LEN          0x0400  /* length will be first received byte */
  336.         __u16 len;              /* msg length                           */
  337.         __u8 *buf;              /* pointer to msg data                  */
  338. };
  339.  
  340. /* To determine what functionality is present */
  341.  
  342. #define I2C_FUNC_I2C                    0x00000001
  343. #define I2C_FUNC_10BIT_ADDR             0x00000002
  344. #define I2C_FUNC_PROTOCOL_MANGLING      0x00000004 /* I2C_M_NOSTART etc. */
  345. #define I2C_FUNC_SMBUS_PEC              0x00000008
  346. #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL  0x00008000 /* SMBus 2.0 */
  347. #define I2C_FUNC_SMBUS_QUICK            0x00010000
  348. #define I2C_FUNC_SMBUS_READ_BYTE        0x00020000
  349. #define I2C_FUNC_SMBUS_WRITE_BYTE       0x00040000
  350. #define I2C_FUNC_SMBUS_READ_BYTE_DATA   0x00080000
  351. #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA  0x00100000
  352. #define I2C_FUNC_SMBUS_READ_WORD_DATA   0x00200000
  353. #define I2C_FUNC_SMBUS_WRITE_WORD_DATA  0x00400000
  354. #define I2C_FUNC_SMBUS_PROC_CALL        0x00800000
  355. #define I2C_FUNC_SMBUS_READ_BLOCK_DATA  0x01000000
  356. #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
  357. #define I2C_FUNC_SMBUS_READ_I2C_BLOCK   0x04000000 /* I2C-like block xfer  */
  358. #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK  0x08000000 /* w/ 1-byte reg. addr. */
  359.  
  360. #define I2C_FUNC_SMBUS_BYTE             (I2C_FUNC_SMBUS_READ_BYTE | \
  361.                                          I2C_FUNC_SMBUS_WRITE_BYTE)
  362. #define I2C_FUNC_SMBUS_BYTE_DATA        (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
  363.                                          I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
  364. #define I2C_FUNC_SMBUS_WORD_DATA        (I2C_FUNC_SMBUS_READ_WORD_DATA | \
  365.                                          I2C_FUNC_SMBUS_WRITE_WORD_DATA)
  366. #define I2C_FUNC_SMBUS_BLOCK_DATA       (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
  367.                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
  368. #define I2C_FUNC_SMBUS_I2C_BLOCK        (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
  369.                                          I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
  370.  
  371. #define I2C_FUNC_SMBUS_EMUL             (I2C_FUNC_SMBUS_QUICK | \
  372.                                          I2C_FUNC_SMBUS_BYTE | \
  373.                                          I2C_FUNC_SMBUS_BYTE_DATA | \
  374.                                          I2C_FUNC_SMBUS_WORD_DATA | \
  375.                                          I2C_FUNC_SMBUS_PROC_CALL | \
  376.                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
  377.                                          I2C_FUNC_SMBUS_I2C_BLOCK | \
  378.                                          I2C_FUNC_SMBUS_PEC)
  379.  
  380. /*
  381.  * Data for SMBus Messages
  382.  */
  383. #define I2C_SMBUS_BLOCK_MAX     32      /* As specified in SMBus standard */
  384. union i2c_smbus_data {
  385.         __u8 byte;
  386.         __u16 word;
  387.         __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
  388.                                /* and one more for user-space compatibility */
  389. };
  390.  
  391. /* i2c_smbus_xfer read or write markers */
  392. #define I2C_SMBUS_READ  1
  393. #define I2C_SMBUS_WRITE 0
  394.  
  395. /* SMBus transaction types (size parameter in the above functions)
  396.    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
  397. #define I2C_SMBUS_QUICK             0
  398. #define I2C_SMBUS_BYTE              1
  399. #define I2C_SMBUS_BYTE_DATA         2
  400. #define I2C_SMBUS_WORD_DATA         3
  401. #define I2C_SMBUS_PROC_CALL         4
  402. #define I2C_SMBUS_BLOCK_DATA        5
  403. #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
  404. #define I2C_SMBUS_BLOCK_PROC_CALL   7           /* SMBus 2.0 */
  405. #define I2C_SMBUS_I2C_BLOCK_DATA    8
  406.  
  407. #endif /* _LINUX_I2C_H */
  408.