include/i2c.h

   1 /*
   2  * (C) Copyright 2001
   3  * Gerald Van Baren, Custom IDEAS, vanbaren@cideas.com.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (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., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  *
  23  * The original I2C interface was
  24  *   (C) 2000 by Paolo Scaffardi (arsenio@tin.it)
  25  *   AIRVENT SAM s.p.a - RIMINI(ITALY)
  26  * but has been changed substantially.
  27  */
  28
  29 #ifndef _I2C_H_
  30 #define _I2C_H_
  31
  32 /*
  33  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  34  *
  35  * The implementation MUST NOT use static or global variables if the
  36  * I2C routines are used to read SDRAM configuration information
  37  * because this is done before the memories are initialized. Limited
  38  * use of stack-based variables are OK (the initial stack size is
  39  * limited).
  40  *
  41  * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
  42  */
  43
  44 /*
  45  * Configuration items.
  46  */
  47 #define I2C_RXTX_LEN    128     /* maximum tx/rx buffer length */
  48
  49 #if defined(CONFIG_I2C_MULTI_BUS)
  50 #define CONFIG_SYS_MAX_I2C_BUS          2
  51 #define I2C_GET_BUS()           i2c_get_bus_num()
  52 #define I2C_SET_BUS(a)          i2c_set_bus_num(a)
  53 #else
  54 #define CONFIG_SYS_MAX_I2C_BUS          1
  55 #define I2C_GET_BUS()           0
  56 #define I2C_SET_BUS(a)
  57 #endif
  58
  59 /* define the I2C bus number for RTC and DTT if not already done */
  60 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
  61 #define CONFIG_SYS_RTC_BUS_NUM          0
  62 #endif
  63 #if !defined(CONFIG_SYS_DTT_BUS_NUM)
  64 #define CONFIG_SYS_DTT_BUS_NUM          0
  65 #endif
  66 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
  67 #define CONFIG_SYS_SPD_BUS_NUM          0
  68 #endif
  69
  70 #ifndef I2C_SOFT_DECLARATIONS
  71 # if defined(CONFIG_MPC8260)
  72 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
  73 # elif defined(CONFIG_8xx)
  74 #  define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  75 # else
  76 #  define I2C_SOFT_DECLARATIONS
  77 # endif
  78 #endif
  79 /*
  80  * Initialization, must be called once on start up, may be called
  81  * repeatedly to change the speed and slave addresses.
  82  */
  83 void i2c_init(int speed, int slaveaddr);
  84 #ifdef CONFIG_SYS_I2C_INIT_BOARD
  85 void i2c_init_board(void);
  86 #endif
  87
  88 #if defined(CONFIG_I2C_MUX)
  89
  90 typedef struct _mux {
  91         uchar   chip;
  92         uchar   channel;
  93         char    *name;
  94         struct _mux     *next;
  95 } I2C_MUX;
  96
  97 typedef struct _mux_device {
  98         int     busid;
  99         I2C_MUX *mux;   /* List of muxes, to reach the device */
 100         struct _mux_device      *next;
 101 } I2C_MUX_DEVICE;
 102
 103 int     i2c_mux_add_device(I2C_MUX_DEVICE *dev);
 104
 105 I2C_MUX_DEVICE  *i2c_mux_search_device(int id);
 106 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
 107 int i2x_mux_select_mux(int bus);
 108 int i2c_mux_ident_muxstring_f (uchar *buf);
 109 #endif
 110
 111 /*
 112  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 113  * not 0 on failure.
 114  */
 115 int i2c_probe(uchar chip);
 116
 117 /*
 118  * Read/Write interface:
 119  *   chip:    I2C chip address, range 0..127
 120  *   addr:    Memory (register) address within the chip
 121  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 122  *              memories, 0 for register type devices with only one
 123  *              register)
 124  *   buffer:  Where to read/write the data
 125  *   len:     How many bytes to read/write
 126  *
 127  *   Returns: 0 on success, not 0 on failure
 128  */
 129 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
 130 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
 131
 132 /*
 133  * Utility routines to read/write registers.
 134  */
 135 uchar i2c_reg_read (uchar chip, uchar reg);
 136 void  i2c_reg_write(uchar chip, uchar reg, uchar val);
 137
 138 /*
 139  * Functions for setting the current I2C bus and its speed
 140  */
 141
 142 /*
 143  * i2c_set_bus_num:
 144  *
 145  *  Change the active I2C bus.  Subsequent read/write calls will
 146  *  go to this one.
 147  *
 148  *      bus - bus index, zero based
 149  *
 150  *      Returns: 0 on success, not 0 on failure
 151  *
 152  */
 153 int i2c_set_bus_num(unsigned int bus);
 154
 155 /*
 156  * i2c_get_bus_num:
 157  *
 158  *  Returns index of currently active I2C bus.  Zero-based.
 159  */
 160
 161 unsigned int i2c_get_bus_num(void);
 162
 163 /*
 164  * i2c_set_bus_speed:
 165  *
 166  *  Change the speed of the active I2C bus
 167  *
 168  *      speed - bus speed in Hz
 169  *
 170  *      Returns: 0 on success, not 0 on failure
 171  *
 172  */
 173 int i2c_set_bus_speed(unsigned int);
 174
 175 /*
 176  * i2c_get_bus_speed:
 177  *
 178  *  Returns speed of currently active I2C bus in Hz
 179  */
 180
 181 unsigned int i2c_get_bus_speed(void);
 182
 183 #endif  /* _I2C_H_ */