drivers/i2c/tsi108_i2c.c

   1 /*
   2  * (C) Copyright 2004 Tundra Semiconductor Corp.
   3  * Author: Alex Bounine
   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  */
  24
  25 #include <config.h>
  26 #include <common.h>
  27
  28 #include <tsi108.h>
  29
  30 #if defined(CONFIG_CMD_I2C)
  31
  32 #define I2C_DELAY       100000
  33 #undef  DEBUG_I2C
  34
  35 #ifdef DEBUG_I2C
  36 #define DPRINT(x) printf (x)
  37 #else
  38 #define DPRINT(x)
  39 #endif
  40
  41 /* All functions assume that Tsi108 I2C block is the only master on the bus */
  42 /* I2C read helper function */
  43
  44 static int i2c_read_byte (
  45                 uint i2c_chan,  /* I2C channel number: 0 - main, 1 - SDC SPD */
  46                 uchar chip_addr,/* I2C device address on the bus */
  47                 uint byte_addr, /* Byte address within I2C device */
  48                 uchar * buffer  /* pointer to data buffer */
  49                 )
  50 {
  51         u32 temp;
  52         u32 to_count = I2C_DELAY;
  53         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
  54         u32 chan_offset = TSI108_I2C_OFFSET;
  55
  56         DPRINT (("I2C read_byte() %d 0x%02x 0x%02x\n",
  57                 i2c_chan, chip_addr, byte_addr));
  58
  59         if (0 != i2c_chan)
  60                 chan_offset = TSI108_I2C_SDRAM_OFFSET;
  61
  62         /* Check if I2C operation is in progress */
  63         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  64
  65         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
  66                           I2C_CNTRL2_START))) {
  67                 /* Set device address and operation (read = 0) */
  68                 temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
  69                     ((chip_addr >> 3) & 0x0F);
  70                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
  71                     temp;
  72
  73                 /* Issue the read command
  74                  * (at this moment all other parameters are 0
  75                  * (size = 1 byte, lane = 0)
  76                  */
  77
  78                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
  79                     (I2C_CNTRL2_START);
  80
  81                 /* Wait until operation completed */
  82                 do {
  83                         /* Read I2C operation status */
  84                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  85
  86                         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START))) {
  87                                 if (0 == (temp &
  88                                      (I2C_CNTRL2_I2C_CFGERR |
  89                                       I2C_CNTRL2_I2C_TO_ERR))
  90                                     ) {
  91                                         op_status = TSI108_I2C_SUCCESS;
  92
  93                                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE +
  94                                                          chan_offset +
  95                                                          I2C_RD_DATA);
  96
  97                                         *buffer = (u8) (temp & 0xFF);
  98                                 } else {
  99                                         /* report HW error */
 100                                         op_status = TSI108_I2C_IF_ERROR;
 101
 102                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 103                                 }
 104
 105                                 break;
 106                         }
 107                 } while (to_count--);
 108         } else {
 109                 op_status = TSI108_I2C_IF_BUSY;
 110
 111                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 112         }
 113
 114         DPRINT (("I2C read_byte() status: 0x%02x\n", op_status));
 115         return op_status;
 116 }
 117
 118 /*
 119  * I2C Read interface as defined in "include/i2c.h" :
 120  *   chip_addr: I2C chip address, range 0..127
 121  *                  (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
 122  *              NOTE: The bit 7 in the chip_addr serves as a channel select.
 123  *              This hack is for enabling "isdram" command on Tsi108 boards
 124  *              without changes to common code. Used for I2C reads only.
 125  *   byte_addr: Memory or register address within the chip
 126  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 127  *              memories, 0 for register type devices with only one
 128  *              register)
 129  *   buffer:    Pointer to destination buffer for data to be read
 130  *   len:       How many bytes to read
 131  *
 132  *   Returns: 0 on success, not 0 on failure
 133  */
 134
 135 int i2c_read (uchar chip_addr, uint byte_addr, int alen,
 136                 uchar * buffer, int len)
 137 {
 138         u32 op_status = TSI108_I2C_PARAM_ERR;
 139         u32 i2c_if = 0;
 140
 141         /* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
 142         if (0xD0 == (chip_addr & ~0x07)) {
 143                 i2c_if = 1;
 144                 chip_addr &= 0x7F;
 145         }
 146         /* Check for valid I2C address */
 147         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 148                 while (len--) {
 149                         op_status = i2c_read_byte(i2c_if, chip_addr, byte_addr++, buffer++);
 150
 151                         if (TSI108_I2C_SUCCESS != op_status) {
 152                                 DPRINT (("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
 153
 154                                 break;
 155                         }
 156                 }
 157         }
 158
 159         DPRINT (("I2C read() status: 0x%02x\n", op_status));
 160         return op_status;
 161 }
 162
 163 /* I2C write helper function */
 164
 165 static int i2c_write_byte (uchar chip_addr,/* I2C device address on the bus */
 166                           uint byte_addr, /* Byte address within I2C device */
 167                           uchar * buffer  /*  pointer to data buffer */
 168                           )
 169 {
 170         u32 temp;
 171         u32 to_count = I2C_DELAY;
 172         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
 173
 174         /* Check if I2C operation is in progress */
 175         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 176
 177         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 178                 /* Place data into the I2C Tx Register */
 179                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 180                           I2C_TX_DATA) = (u32) * buffer;
 181
 182                 /* Set device address and operation  */
 183                 temp =
 184                     I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
 185                     ((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
 186                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 187                           I2C_CNTRL1) = temp;
 188
 189                 /* Issue the write command (at this moment all other parameters
 190                  * are 0 (size = 1 byte, lane = 0)
 191                  */
 192
 193                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 194                           I2C_CNTRL2) = (I2C_CNTRL2_START);
 195
 196                 op_status = TSI108_I2C_TIMEOUT_ERR;
 197
 198                 /* Wait until operation completed */
 199                 do {
 200                         /* Read I2C operation status */
 201                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 202
 203                         if (0 == (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 204                                 if (0 == (temp &
 205                                      (I2C_CNTRL2_I2C_CFGERR |
 206                                       I2C_CNTRL2_I2C_TO_ERR))) {
 207                                         op_status = TSI108_I2C_SUCCESS;
 208                                 } else {
 209                                         /* report detected HW error */
 210                                         op_status = TSI108_I2C_IF_ERROR;
 211
 212                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 213                                 }
 214
 215                                 break;
 216                         }
 217
 218                 } while (to_count--);
 219         } else {
 220                 op_status = TSI108_I2C_IF_BUSY;
 221
 222                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 223         }
 224
 225         return op_status;
 226 }
 227
 228 /*
 229  * I2C Write interface as defined in "include/i2c.h" :
 230  *   chip_addr: I2C chip address, range 0..127
 231  *   byte_addr: Memory or register address within the chip
 232  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 233  *              memories, 0 for register type devices with only one
 234  *              register)
 235  *   buffer:    Pointer to data to be written
 236  *   len:       How many bytes to write
 237  *
 238  *   Returns: 0 on success, not 0 on failure
 239  */
 240
 241 int i2c_write (uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
 242               int len)
 243 {
 244         u32 op_status = TSI108_I2C_PARAM_ERR;
 245
 246         /* Check for valid I2C address */
 247         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 248                 while (len--) {
 249                         op_status =
 250                             i2c_write_byte (chip_addr, byte_addr++, buffer++);
 251
 252                         if (TSI108_I2C_SUCCESS != op_status) {
 253                                 DPRINT (("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
 254
 255                                 break;
 256                         }
 257                 }
 258         }
 259
 260         return op_status;
 261 }
 262
 263 /*
 264  * I2C interface function as defined in "include/i2c.h".
 265  * Probe the given I2C chip address by reading single byte from offset 0.
 266  * Returns 0 if a chip responded, not 0 on failure.
 267  */
 268
 269 int i2c_probe (uchar chip)
 270 {
 271         u32 tmp;
 272
 273         /*
 274          * Try to read the first location of the chip.
 275          * The Tsi108 HW doesn't support sending just the chip address
 276          * and checkong for an <ACK> back.
 277          */
 278         return i2c_read (chip, 0, 1, (uchar *)&tmp, 1);
 279 }
 280
 281 #endif