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 #ifdef  CONFIG_I2C_MULTI_BUS
  50 #define MAX_I2C_BUS                     2
  51 #define I2C_MULTI_BUS                   1
  52 #else
  53 #define MAX_I2C_BUS                     1
  54 #define I2C_MULTI_BUS                   0
  55 #endif
  56
  57 #if !defined(CONFIG_SYS_MAX_I2C_BUS)
  58 #define CONFIG_SYS_MAX_I2C_BUS          MAX_I2C_BUS
  59 #endif
  60
  61 /* define the I2C bus number for RTC and DTT if not already done */
  62 #if !defined(CONFIG_SYS_RTC_BUS_NUM)
  63 #define CONFIG_SYS_RTC_BUS_NUM          0
  64 #endif
  65 #if !defined(CONFIG_SYS_DTT_BUS_NUM)
  66 #define CONFIG_SYS_DTT_BUS_NUM          0
  67 #endif
  68 #if !defined(CONFIG_SYS_SPD_BUS_NUM)
  69 #define CONFIG_SYS_SPD_BUS_NUM          0
  70 #endif
  71
  72 #ifndef I2C_SOFT_DECLARATIONS
  73 # if defined(CONFIG_MPC8260)
  74 #  define I2C_SOFT_DECLARATIONS volatile ioport_t *iop = ioport_addr((immap_t *)CONFIG_SYS_IMMR, I2C_PORT);
  75 # elif defined(CONFIG_8xx)
  76 #  define I2C_SOFT_DECLARATIONS volatile immap_t *immr = (immap_t *)CONFIG_SYS_IMMR;
  77
  78 # elif (defined(CONFIG_AT91RM9200) || \
  79         defined(CONFIG_AT91SAM9260) ||  defined(CONFIG_AT91SAM9261) || \
  80         defined(CONFIG_AT91SAM9263)) && !defined(CONFIG_AT91_LEGACY)
  81 #  define I2C_SOFT_DECLARATIONS at91_pio_t *pio = (at91_pio_t *) ATMEL_BASE_PIOA;
  82 # else
  83 #  define I2C_SOFT_DECLARATIONS
  84 # endif
  85 #endif
  86
  87 #ifdef CONFIG_8xx
  88 /* Set default value for the I2C bus speed on 8xx. In the
  89  * future, we'll define these in all 8xx board config files.
  90  */
  91 #ifndef CONFIG_SYS_I2C_SPEED
  92 #define CONFIG_SYS_I2C_SPEED    50000
  93 #endif
  94 #endif
  95
  96 /*
  97  * Many boards/controllers/drivers don't support an I2C slave interface so
  98  * provide a default slave address for them for use in common code.  A real
  99  * value for CONFIG_SYS_I2C_SLAVE should be defined for any board which does
 100  * support a slave interface.
 101  */
 102 #ifndef CONFIG_SYS_I2C_SLAVE
 103 #define CONFIG_SYS_I2C_SLAVE    0xfe
 104 #endif
 105
 106 /*
 107  * Initialization, must be called once on start up, may be called
 108  * repeatedly to change the speed and slave addresses.
 109  */
 110 void i2c_init(int speed, int slaveaddr);
 111 void i2c_init_board(void);
 112 #ifdef CONFIG_SYS_I2C_BOARD_LATE_INIT
 113 void i2c_board_late_init(void);
 114 #endif
 115
 116 #if defined(CONFIG_I2C_MUX)
 117
 118 typedef struct _mux {
 119         uchar   chip;
 120         uchar   channel;
 121         char    *name;
 122         struct _mux     *next;
 123 } I2C_MUX;
 124
 125 typedef struct _mux_device {
 126         int     busid;
 127         I2C_MUX *mux;   /* List of muxes, to reach the device */
 128         struct _mux_device      *next;
 129 } I2C_MUX_DEVICE;
 130
 131 I2C_MUX_DEVICE  *i2c_mux_search_device(int id);
 132 I2C_MUX_DEVICE *i2c_mux_ident_muxstring (uchar *buf);
 133 int i2x_mux_select_mux(int bus);
 134 int i2c_mux_ident_muxstring_f (uchar *buf);
 135 #endif
 136
 137 /*
 138  * Probe the given I2C chip address.  Returns 0 if a chip responded,
 139  * not 0 on failure.
 140  */
 141 int i2c_probe(uchar chip);
 142
 143 /*
 144  * Read/Write interface:
 145  *   chip:    I2C chip address, range 0..127
 146  *   addr:    Memory (register) address within the chip
 147  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
 148  *              memories, 0 for register type devices with only one
 149  *              register)
 150  *   buffer:  Where to read/write the data
 151  *   len:     How many bytes to read/write
 152  *
 153  *   Returns: 0 on success, not 0 on failure
 154  */
 155 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len);
 156 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len);
 157
 158 /*
 159  * Utility routines to read/write registers.
 160  */
 161 static inline u8 i2c_reg_read(u8 addr, u8 reg)
 162 {
 163         u8 buf;
 164
 165 #ifdef CONFIG_8xx
 166         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 167         i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 168 #endif
 169
 170 #ifdef DEBUG
 171         printf("%s: addr=0x%02x, reg=0x%02x\n", __func__, addr, reg);
 172 #endif
 173
 174         i2c_read(addr, reg, 1, &buf, 1);
 175
 176         return buf;
 177 }
 178
 179 static inline void i2c_reg_write(u8 addr, u8 reg, u8 val)
 180 {
 181 #ifdef CONFIG_8xx
 182         /* MPC8xx needs this.  Maybe one day we can get rid of it. */
 183         i2c_init(CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
 184 #endif
 185
 186 #ifdef DEBUG
 187         printf("%s: addr=0x%02x, reg=0x%02x, val=0x%02x\n",
 188                __func__, addr, reg, val);
 189 #endif
 190
 191         i2c_write(addr, reg, 1, &val, 1);
 192 }
 193
 194 /*
 195  * Functions for setting the current I2C bus and its speed
 196  */
 197
 198 /*
 199  * i2c_set_bus_num:
 200  *
 201  *  Change the active I2C bus.  Subsequent read/write calls will
 202  *  go to this one.
 203  *
 204  *      bus - bus index, zero based
 205  *
 206  *      Returns: 0 on success, not 0 on failure
 207  *
 208  */
 209 int i2c_set_bus_num(unsigned int bus);
 210
 211 /*
 212  * i2c_get_bus_num:
 213  *
 214  *  Returns index of currently active I2C bus.  Zero-based.
 215  */
 216
 217 unsigned int i2c_get_bus_num(void);
 218
 219 /*
 220  * i2c_set_bus_speed:
 221  *
 222  *  Change the speed of the active I2C bus
 223  *
 224  *      speed - bus speed in Hz
 225  *
 226  *      Returns: 0 on success, not 0 on failure
 227  *
 228  */
 229 int i2c_set_bus_speed(unsigned int);
 230
 231 /*
 232  * i2c_get_bus_speed:
 233  *
 234  *  Returns speed of currently active I2C bus in Hz
 235  */
 236
 237 unsigned int i2c_get_bus_speed(void);
 238
 239 /* NOTE: These two functions MUST be always_inline to avoid code growth! */
 240 static inline unsigned int I2C_GET_BUS(void) __attribute__((always_inline));
 241 static inline unsigned int I2C_GET_BUS(void)
 242 {
 243         return I2C_MULTI_BUS ? i2c_get_bus_num() : 0;
 244 }
 245
 246 static inline void I2C_SET_BUS(unsigned int bus) __attribute__((always_inline));
 247 static inline void I2C_SET_BUS(unsigned int bus)
 248 {
 249         if (I2C_MULTI_BUS)
 250                 i2c_set_bus_num(bus);
 251 }
 252
 253 #endif  /* _I2C_H_ */