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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., 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/types.h>
  30. #ifdef __KERNEL__
  31. #include <linux/module.h>
  32. #include <linux/i2c-id.h>
  33. #include <linux/mod_devicetable.h>
  34. #include <linux/sched.h>        /* for completion */
  35. #include <linux/mutex.h>
  36. #include <linux/jiffies.h>
  37.  
  38. extern struct bus_type i2c_bus_type;
  39. extern struct device_type i2c_adapter_type;
  40.  
  41. /* --- General options ------------------------------------------------ */
  42.  
  43. struct i2c_msg;
  44. struct i2c_algorithm;
  45. struct i2c_adapter;
  46. struct i2c_client;
  47. struct i2c_driver;
  48. union i2c_smbus_data;
  49. struct i2c_board_info;
  50.  
  51.  
  52. /* Transfer num messages.
  53.  */
  54. extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
  55.                         int num);
  56.  
  57. /**
  58.  * struct i2c_driver - represent an I2C device driver
  59.  * @class: What kind of i2c device we instantiate (for detect)
  60.  * @attach_adapter: Callback for bus addition (deprecated)
  61.  * @probe: Callback for device binding
  62.  * @remove: Callback for device unbinding
  63.  * @shutdown: Callback for device shutdown
  64.  * @suspend: Callback for device suspend
  65.  * @resume: Callback for device resume
  66.  * @alert: Alert callback, for example for the SMBus alert protocol
  67.  * @command: Callback for bus-wide signaling (optional)
  68.  * @driver: Device driver model driver
  69.  * @id_table: List of I2C devices supported by this driver
  70.  * @detect: Callback for device detection
  71.  * @address_list: The I2C addresses to probe (for detect)
  72.  * @clients: List of detected clients we created (for i2c-core use only)
  73.  *
  74.  * The driver.owner field should be set to the module owner of this driver.
  75.  * The driver.name field should be set to the name of this driver.
  76.  *
  77.  * For automatic device detection, both @detect and @address_list must
  78.  * be defined. @class should also be set, otherwise only devices forced
  79.  * with module parameters will be created. The detect function must
  80.  * fill at least the name field of the i2c_board_info structure it is
  81.  * handed upon successful detection, and possibly also the flags field.
  82.  *
  83.  * If @detect is missing, the driver will still work fine for enumerated
  84.  * devices. Detected devices simply won't be supported. This is expected
  85.  * for the many I2C/SMBus devices which can't be detected reliably, and
  86.  * the ones which can always be enumerated in practice.
  87.  *
  88.  * The i2c_client structure which is handed to the @detect callback is
  89.  * not a real i2c_client. It is initialized just enough so that you can
  90.  * call i2c_smbus_read_byte_data and friends on it. Don't do anything
  91.  * else with it. In particular, calling dev_dbg and friends on it is
  92.  * not allowed.
  93.  */
  94. struct i2c_driver {
  95.         unsigned int class;
  96.  
  97.         /* Notifies the driver that a new bus has appeared. You should avoid
  98.          * using this, it will be removed in a near future.
  99.          */
  100.         int (*attach_adapter)(struct i2c_adapter *) __deprecated;
  101.  
  102.         /* Standard driver model interfaces */
  103.         int (*probe)(struct i2c_client *, const struct i2c_device_id *);
  104.         int (*remove)(struct i2c_client *);
  105.  
  106.         /* driver model interfaces that don't relate to enumeration  */
  107.         void (*shutdown)(struct i2c_client *);
  108. //      int (*suspend)(struct i2c_client *, pm_message_t mesg);
  109.         int (*resume)(struct i2c_client *);
  110.  
  111.         /* Alert callback, for example for the SMBus alert protocol.
  112.          * The format and meaning of the data value depends on the protocol.
  113.          * For the SMBus alert protocol, there is a single bit of data passed
  114.          * as the alert response's low bit ("event flag").
  115.          */
  116.         void (*alert)(struct i2c_client *, unsigned int data);
  117.  
  118.         /* a ioctl like command that can be used to perform specific functions
  119.          * with the device.
  120.          */
  121.         int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);
  122.  
  123. //      struct device_driver driver;
  124.         const struct i2c_device_id *id_table;
  125.  
  126.         /* Device detection callback for automatic device creation */
  127. //      int (*detect)(struct i2c_client *, struct i2c_board_info *);
  128.         const unsigned short *address_list;
  129.         struct list_head clients;
  130. };
  131. #define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)
  132.  
  133. /**
  134.  * struct i2c_client - represent an I2C slave device
  135.  * @flags: I2C_CLIENT_TEN indicates the device uses a ten bit chip address;
  136.  *      I2C_CLIENT_PEC indicates it uses SMBus Packet Error Checking
  137.  * @addr: Address used on the I2C bus connected to the parent adapter.
  138.  * @name: Indicates the type of the device, usually a chip name that's
  139.  *      generic enough to hide second-sourcing and compatible revisions.
  140.  * @adapter: manages the bus segment hosting this I2C device
  141.  * @dev: Driver model device node for the slave.
  142.  * @irq: indicates the IRQ generated by this device (if any)
  143.  * @detected: member of an i2c_driver.clients list or i2c-core's
  144.  *      userspace_devices list
  145.  * @slave_cb: Callback when I2C slave mode of an adapter is used. The adapter
  146.  *      calls it to pass on slave events to the slave driver.
  147.  *
  148.  * An i2c_client identifies a single device (i.e. chip) connected to an
  149.  * i2c bus. The behaviour exposed to Linux is defined by the driver
  150.  * managing the device.
  151.  */
  152. struct i2c_client {
  153.         unsigned short flags;           /* div., see below              */
  154.         unsigned short addr;            /* chip address - NOTE: 7bit    */
  155.                                         /* addresses are stored in the  */
  156.                                         /* _LOWER_ 7 bits               */
  157.         char name[I2C_NAME_SIZE];
  158.         struct i2c_adapter *adapter;    /* the adapter we sit on        */
  159.         struct device dev;              /* the device structure         */
  160.         int irq;                        /* irq issued by device         */
  161.         struct list_head detected;
  162. };
  163. #define to_i2c_client(d) container_of(d, struct i2c_client, dev)
  164.  
  165. extern struct i2c_client *i2c_verify_client(struct device *dev);
  166. extern struct i2c_adapter *i2c_verify_adapter(struct device *dev);
  167.  
  168. enum i2c_slave_event {
  169.         I2C_SLAVE_REQ_READ_START,
  170.         I2C_SLAVE_REQ_READ_END,
  171.         I2C_SLAVE_REQ_WRITE_START,
  172.         I2C_SLAVE_REQ_WRITE_END,
  173.         I2C_SLAVE_STOP,
  174. };
  175. /**
  176.  * struct i2c_board_info - template for device creation
  177.  * @type: chip type, to initialize i2c_client.name
  178.  * @flags: to initialize i2c_client.flags
  179.  * @addr: stored in i2c_client.addr
  180.  * @platform_data: stored in i2c_client.dev.platform_data
  181.  * @archdata: copied into i2c_client.dev.archdata
  182.  * @of_node: pointer to OpenFirmware device node
  183.  * @acpi_node: ACPI device node
  184.  * @irq: stored in i2c_client.irq
  185.  *
  186.  * I2C doesn't actually support hardware probing, although controllers and
  187.  * devices may be able to use I2C_SMBUS_QUICK to tell whether or not there's
  188.  * a device at a given address.  Drivers commonly need more information than
  189.  * that, such as chip type, configuration, associated IRQ, and so on.
  190.  *
  191.  * i2c_board_info is used to build tables of information listing I2C devices
  192.  * that are present.  This information is used to grow the driver model tree.
  193.  * For mainboards this is done statically using i2c_register_board_info();
  194.  * bus numbers identify adapters that aren't yet available.  For add-on boards,
  195.  * i2c_new_device() does this dynamically with the adapter already known.
  196.  */
  197. struct i2c_board_info {
  198.         char            type[I2C_NAME_SIZE];
  199.         unsigned short  flags;
  200.         unsigned short  addr;
  201.         void            *platform_data;
  202.         struct dev_archdata     *archdata;
  203.         int             irq;
  204. };
  205.  
  206. /**
  207.  * I2C_BOARD_INFO - macro used to list an i2c device and its address
  208.  * @dev_type: identifies the device type
  209.  * @dev_addr: the device's address on the bus.
  210.  *
  211.  * This macro initializes essential fields of a struct i2c_board_info,
  212.  * declaring what has been provided on a particular board.  Optional
  213.  * fields (such as associated irq, or device-specific platform_data)
  214.  * are provided using conventional syntax.
  215.  */
  216. #define I2C_BOARD_INFO(dev_type, dev_addr) \
  217.         .type = dev_type, .addr = (dev_addr)
  218. /*
  219.  * The following structs are for those who like to implement new bus drivers:
  220.  * i2c_algorithm is the interface to a class of hardware solutions which can
  221.  * be addressed using the same bus algorithms - i.e. bit-banging or the PCF8584
  222.  * to name two of the most common.
  223.  *
  224.  * The return codes from the @master_xfer field should indicate the type of
  225.  * error code that occurred during the transfer, as documented in the kernel
  226.  * Documentation file Documentation/i2c/fault-codes.
  227.  */
  228. struct i2c_algorithm {
  229.         /* If an adapter algorithm can't do I2C-level access, set master_xfer
  230.            to NULL. If an adapter algorithm can do SMBus access, set
  231.            smbus_xfer. If set to NULL, the SMBus protocol is simulated
  232.            using common I2C messages */
  233.         /* master_xfer should return the number of messages successfully
  234.            processed, or a negative value on error */
  235.         int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
  236.                            int num);
  237.         int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
  238.                            unsigned short flags, char read_write,
  239.                            u8 command, int size, union i2c_smbus_data *data);
  240.  
  241.         /* To determine what the adapter supports */
  242.         u32 (*functionality) (struct i2c_adapter *);
  243. };
  244.  
  245. int i2c_recover_bus(struct i2c_adapter *adap);
  246.  
  247. /* Generic recovery routines */
  248. int i2c_generic_gpio_recovery(struct i2c_adapter *adap);
  249. int i2c_generic_scl_recovery(struct i2c_adapter *adap);
  250.  
  251. /*
  252.  * i2c_adapter is the structure used to identify a physical i2c bus along
  253.  * with the access algorithms necessary to access it.
  254.  */
  255. struct i2c_adapter {
  256.         struct module *owner;
  257.         unsigned int class;               /* classes to allow probing for */
  258.         const struct i2c_algorithm *algo; /* the algorithm to access the bus */
  259.         void *algo_data;
  260.  
  261.         /* data fields that are valid for all devices   */
  262. //      struct rt_mutex bus_lock;
  263.  
  264.         int timeout;                    /* in jiffies */
  265.     int retries;
  266.     struct device dev;      /* the adapter device */
  267.  
  268.     int nr;
  269.     char name[48];
  270. };
  271. #define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)
  272.  
  273. static inline void *i2c_get_adapdata(struct i2c_adapter *dev)
  274. {
  275.         return dev_get_drvdata(&dev->dev);
  276. }
  277.  
  278. static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
  279. {
  280.         dev_set_drvdata(&dev->dev, data);
  281. }
  282.  
  283. /* Adapter locking functions, exported for shared pin cases */
  284. void i2c_lock_adapter(struct i2c_adapter *);
  285. void i2c_unlock_adapter(struct i2c_adapter *);
  286.  
  287. /*flags for the client struct: */
  288. #define I2C_CLIENT_PEC  0x04            /* Use Packet Error Checking */
  289. #define I2C_CLIENT_TEN  0x10            /* we have a ten bit chip address */
  290.                                         /* Must equal I2C_M_TEN below */
  291. #define I2C_CLIENT_WAKE 0x80            /* for board_info; true iff can wake */
  292. #define I2C_CLIENT_SCCB 0x9000          /* Use Omnivision SCCB protocol */
  293.                                         /* Must match I2C_M_STOP|IGNORE_NAK */
  294.  
  295. /* i2c adapter classes (bitmask) */
  296. #define I2C_CLASS_HWMON         (1<<0)  /* lm_sensors, ... */
  297. #define I2C_CLASS_DDC           (1<<3)  /* DDC bus on graphics adapters */
  298. #define I2C_CLASS_SPD           (1<<7)  /* Memory modules */
  299. #define I2C_CLASS_DEPRECATED    (1<<8)  /* Warn users that adapter will stop using classes */
  300.  
  301. /* Internal numbers to terminate lists */
  302. #define I2C_CLIENT_END          0xfffeU
  303.  
  304. /* Construct an I2C_CLIENT_END-terminated array of i2c addresses */
  305. #define I2C_ADDRS(addr, addrs...) \
  306.         ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })
  307.  
  308.  
  309. #endif /* __KERNEL__ */
  310.  
  311. /**
  312.  * struct i2c_msg - an I2C transaction segment beginning with START
  313.  * @addr: Slave address, either seven or ten bits.  When this is a ten
  314.  *      bit address, I2C_M_TEN must be set in @flags and the adapter
  315.  *      must support I2C_FUNC_10BIT_ADDR.
  316.  * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
  317.  *      provided unless the adapter exported the relevant I2C_FUNC_*
  318.  *      flags through i2c_check_functionality().
  319.  * @len: Number of data bytes in @buf being read from or written to the
  320.  *      I2C slave address.  For read transactions where I2C_M_RECV_LEN
  321.  *      is set, the caller guarantees that this buffer can hold up to
  322.  *      32 bytes in addition to the initial length byte sent by the
  323.  *      slave (plus, if used, the SMBus PEC); and this value will be
  324.  *      incremented by the number of block data bytes received.
  325.  * @buf: The buffer into which data is read, or from which it's written.
  326.  *
  327.  * An i2c_msg is the low level representation of one segment of an I2C
  328.  * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
  329.  * to userspace from i2c-dev, and to I2C adapter drivers through the
  330.  * @i2c_adapter.@master_xfer() method.
  331.  *
  332.  * Except when I2C "protocol mangling" is used, all I2C adapters implement
  333.  * the standard rules for I2C transactions.  Each transaction begins with a
  334.  * START.  That is followed by the slave address, and a bit encoding read
  335.  * versus write.  Then follow all the data bytes, possibly including a byte
  336.  * with SMBus PEC.  The transfer terminates with a NAK, or when all those
  337.  * bytes have been transferred and ACKed.  If this is the last message in a
  338.  * group, it is followed by a STOP.  Otherwise it is followed by the next
  339.  * @i2c_msg transaction segment, beginning with a (repeated) START.
  340.  *
  341.  * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
  342.  * passing certain @flags may have changed those standard protocol behaviors.
  343.  * Those flags are only for use with broken/nonconforming slaves, and with
  344.  * adapters which are known to support the specific mangling options they
  345.  * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
  346.  */
  347. struct i2c_msg {
  348.         __u16 addr;     /* slave address                        */
  349.         __u16 flags;
  350. #define I2C_M_TEN               0x0010  /* this is a ten bit chip address */
  351. #define I2C_M_RD                0x0001  /* read data, from slave to master */
  352. #define I2C_M_NOSTART           0x4000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  353. #define I2C_M_REV_DIR_ADDR      0x2000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  354. #define I2C_M_IGNORE_NAK        0x1000  /* if I2C_FUNC_PROTOCOL_MANGLING */
  355. #define I2C_M_NO_RD_ACK         0x0800  /* if I2C_FUNC_PROTOCOL_MANGLING */
  356. #define I2C_M_RECV_LEN          0x0400  /* length will be first received byte */
  357.         __u16 len;              /* msg length                           */
  358.         __u8 *buf;              /* pointer to msg data                  */
  359. };
  360.  
  361. /* To determine what functionality is present */
  362.  
  363. #define I2C_FUNC_I2C                    0x00000001
  364. #define I2C_FUNC_10BIT_ADDR             0x00000002
  365. #define I2C_FUNC_PROTOCOL_MANGLING      0x00000004 /* I2C_M_NOSTART etc. */
  366. #define I2C_FUNC_SMBUS_PEC              0x00000008
  367. #define I2C_FUNC_SMBUS_BLOCK_PROC_CALL  0x00008000 /* SMBus 2.0 */
  368. #define I2C_FUNC_SMBUS_QUICK            0x00010000
  369. #define I2C_FUNC_SMBUS_READ_BYTE        0x00020000
  370. #define I2C_FUNC_SMBUS_WRITE_BYTE       0x00040000
  371. #define I2C_FUNC_SMBUS_READ_BYTE_DATA   0x00080000
  372. #define I2C_FUNC_SMBUS_WRITE_BYTE_DATA  0x00100000
  373. #define I2C_FUNC_SMBUS_READ_WORD_DATA   0x00200000
  374. #define I2C_FUNC_SMBUS_WRITE_WORD_DATA  0x00400000
  375. #define I2C_FUNC_SMBUS_PROC_CALL        0x00800000
  376. #define I2C_FUNC_SMBUS_READ_BLOCK_DATA  0x01000000
  377. #define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
  378. #define I2C_FUNC_SMBUS_READ_I2C_BLOCK   0x04000000 /* I2C-like block xfer  */
  379. #define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK  0x08000000 /* w/ 1-byte reg. addr. */
  380.  
  381. #define I2C_FUNC_SMBUS_BYTE             (I2C_FUNC_SMBUS_READ_BYTE | \
  382.                                          I2C_FUNC_SMBUS_WRITE_BYTE)
  383. #define I2C_FUNC_SMBUS_BYTE_DATA        (I2C_FUNC_SMBUS_READ_BYTE_DATA | \
  384.                                          I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
  385. #define I2C_FUNC_SMBUS_WORD_DATA        (I2C_FUNC_SMBUS_READ_WORD_DATA | \
  386.                                          I2C_FUNC_SMBUS_WRITE_WORD_DATA)
  387. #define I2C_FUNC_SMBUS_BLOCK_DATA       (I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
  388.                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
  389. #define I2C_FUNC_SMBUS_I2C_BLOCK        (I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
  390.                                          I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)
  391.  
  392. #define I2C_FUNC_SMBUS_EMUL             (I2C_FUNC_SMBUS_QUICK | \
  393.                                          I2C_FUNC_SMBUS_BYTE | \
  394.                                          I2C_FUNC_SMBUS_BYTE_DATA | \
  395.                                          I2C_FUNC_SMBUS_WORD_DATA | \
  396.                                          I2C_FUNC_SMBUS_PROC_CALL | \
  397.                                          I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
  398.                                          I2C_FUNC_SMBUS_I2C_BLOCK | \
  399.                                          I2C_FUNC_SMBUS_PEC)
  400.  
  401. /*
  402.  * Data for SMBus Messages
  403.  */
  404. #define I2C_SMBUS_BLOCK_MAX     32      /* As specified in SMBus standard */
  405. union i2c_smbus_data {
  406.         __u8 byte;
  407.         __u16 word;
  408.         __u8 block[I2C_SMBUS_BLOCK_MAX + 2]; /* block[0] is used for length */
  409.                                /* and one more for user-space compatibility */
  410. };
  411.  
  412. /* i2c_smbus_xfer read or write markers */
  413. #define I2C_SMBUS_READ  1
  414. #define I2C_SMBUS_WRITE 0
  415.  
  416. /* SMBus transaction types (size parameter in the above functions)
  417.    Note: these no longer correspond to the (arbitrary) PIIX4 internal codes! */
  418. #define I2C_SMBUS_QUICK             0
  419. #define I2C_SMBUS_BYTE              1
  420. #define I2C_SMBUS_BYTE_DATA         2
  421. #define I2C_SMBUS_WORD_DATA         3
  422. #define I2C_SMBUS_PROC_CALL         4
  423. #define I2C_SMBUS_BLOCK_DATA        5
  424. #define I2C_SMBUS_I2C_BLOCK_BROKEN  6
  425. #define I2C_SMBUS_BLOCK_PROC_CALL   7           /* SMBus 2.0 */
  426. #define I2C_SMBUS_I2C_BLOCK_DATA    8
  427.  
  428. #define i2c_add_adapter(x)      0
  429. #define i2c_del_adapter(x)
  430.  
  431. #endif /* _LINUX_I2C_H */
  432.