drivers/media/dvb-frontends/drx39xyj/bsp_i2c.h

   1 /*
   2   I2C API, implementation depends on board specifics
   3
   4   Copyright (c), 2004-2005,2007-2010 Trident Microsystems, Inc.
   5   All rights reserved.
   6
   7   Redistribution and use in source and binary forms, with or without
   8   modification, are permitted provided that the following conditions are met:
   9
  10   * Redistributions of source code must retain the above copyright notice,
  11     this list of conditions and the following disclaimer.
  12   * Redistributions in binary form must reproduce the above copyright notice,
  13     this list of conditions and the following disclaimer in the documentation
  14         and/or other materials provided with the distribution.
  15   * Neither the name of Trident Microsystems nor Hauppauge Computer Works
  16     nor the names of its contributors may be used to endorse or promote
  17         products derived from this software without specific prior written
  18         permission.
  19
  20   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  21   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  24   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  25   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  26   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  29   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  30   POSSIBILITY OF SUCH DAMAGE.
  31
  32   This module encapsulates I2C access.In some applications several devices
  33   share one I2C bus. If these devices have the same I2C address some kind
  34   off "switch" must be implemented to ensure error free communication with
  35   one device.  In case such a "switch" is used, the device ID can be used
  36   to implement control over this "switch".
  37 */
  38
  39 #ifndef __BSPI2C_H__
  40 #define __BSPI2C_H__
  41
  42 #include "bsp_types.h"
  43
  44 /*
  45  * This structure contains the I2C address, the device ID and a user_data pointer.
  46  * The user_data pointer can be used for application specific purposes.
  47  */
  48 struct i2c_device_addr {
  49         u16 i2c_addr;           /* The I2C address of the device. */
  50         u16 i2c_dev_id;         /* The device identifier. */
  51         void *user_data;                /* User data pointer */
  52 };
  53
  54
  55 /**
  56 * \def IS_I2C_10BIT( addr )
  57 * \brief Determine if I2C address 'addr' is a 10 bits address or not.
  58 * \param addr The I2C address.
  59 * \return int.
  60 * \retval 0 if address is not a 10 bits I2C address.
  61 * \retval 1 if address is a 10 bits I2C address.
  62 */
  63 #define IS_I2C_10BIT(addr) \
  64          (((addr) & 0xF8) == 0xF0)
  65
  66 /*------------------------------------------------------------------------------
  67 Exported FUNCTIONS
  68 ------------------------------------------------------------------------------*/
  69
  70 /**
  71 * \fn drxbsp_i2c_init()
  72 * \brief Initialize I2C communication module.
  73 * \return drx_status_t Return status.
  74 * \retval 0 Initialization successful.
  75 * \retval -EIO Initialization failed.
  76 */
  77         drx_status_t drxbsp_i2c_init(void);
  78
  79 /**
  80 * \fn drxbsp_i2c_term()
  81 * \brief Terminate I2C communication module.
  82 * \return drx_status_t Return status.
  83 * \retval 0 Termination successful.
  84 * \retval -EIO Termination failed.
  85 */
  86         drx_status_t drxbsp_i2c_term(void);
  87
  88 /**
  89 * \fn drx_status_t drxbsp_i2c_write_read( struct i2c_device_addr *w_dev_addr,
  90 *                                       u16 w_count,
  91 *                                       u8 *wData,
  92 *                                       struct i2c_device_addr *r_dev_addr,
  93 *                                       u16 r_count,
  94 *                                       u8 *r_data)
  95 * \brief Read and/or write count bytes from I2C bus, store them in data[].
  96 * \param w_dev_addr The device i2c address and the device ID to write to
  97 * \param w_count   The number of bytes to write
  98 * \param wData    The array to write the data to
  99 * \param r_dev_addr The device i2c address and the device ID to read from
 100 * \param r_count   The number of bytes to read
 101 * \param r_data    The array to read the data from
 102 * \return drx_status_t Return status.
 103 * \retval 0 Succes.
 104 * \retval -EIO Failure.
 105 * \retval -EINVAL Parameter 'wcount' is not zero but parameter
 106 *                                       'wdata' contains NULL.
 107 *                                       Idem for 'rcount' and 'rdata'.
 108 *                                       Both w_dev_addr and r_dev_addr are NULL.
 109 *
 110 * This function must implement an atomic write and/or read action on the I2C bus
 111 * No other process may use the I2C bus when this function is executing.
 112 * The critical section of this function runs from and including the I2C
 113 * write, up to and including the I2C read action.
 114 *
 115 * The device ID can be useful if several devices share an I2C address.
 116 * It can be used to control a "switch" on the I2C bus to the correct device.
 117 */
 118         drx_status_t drxbsp_i2c_write_read(struct i2c_device_addr *w_dev_addr,
 119                                          u16 w_count,
 120                                          u8 *w_data,
 121                                          struct i2c_device_addr *r_dev_addr,
 122                                          u16 r_count, u8 *r_data);
 123
 124 /**
 125 * \fn drxbsp_i2c_error_text()
 126 * \brief Returns a human readable error.
 127 * Counter part of numerical drx_i2c_error_g.
 128 *
 129 * \return char* Pointer to human readable error text.
 130 */
 131         char *drxbsp_i2c_error_text(void);
 132
 133 /**
 134 * \var drx_i2c_error_g;
 135 * \brief I2C specific error codes, platform dependent.
 136 */
 137         extern int drx_i2c_error_g;
 138
 139 #endif                          /* __BSPI2C_H__ */