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 #ifdef CONFIG_TSI108_I2C
  29 #include <tsi108.h>
  30
  31 #if defined(CONFIG_CMD_I2C)
  32
  33 #define I2C_DELAY       100000
  34 #undef  DEBUG_I2C
  35
  36 #ifdef DEBUG_I2C
  37 #define DPRINT(x) printf (x)
  38 #else
  39 #define DPRINT(x)
  40 #endif
  41
  42 /* All functions assume that Tsi108 I2C block is the only master on the bus */
  43 /* I2C read helper function */
  44
  45 static int i2c_read_byte (
  46                 uint i2c_chan,  /* I2C channel number: 0 - main, 1 - SDC SPD */
  47                 uchar chip_addr,/* I2C device address on the bus */
  48                 uint byte_addr, /* Byte address within I2C device */
  49                 uchar * buffer  /* pointer to data buffer */
  50                 )
  51 {
  52         u32 temp;
  53         u32 to_count = I2C_DELAY;
  54         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
  55         u32 chan_offset = TSI108_I2C_OFFSET;
  56
  57         DPRINT (("I2C read_byte() %d 0x%02x 0x%02x\n",
  58                 i2c_chan, chip_addr, byte_addr));
  59
  60         if (0 != i2c_chan)
  61                 chan_offset = TSI108_I2C_SDRAM_OFFSET;
  62
  63         /* Check if I2C operation is in progress */
  64         temp = *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  65
  66         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
  67                           I2C_CNTRL2_START))) {
  68                 /* Set device address and operation (read = 0) */
  69                 temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
  70                     ((chip_addr >> 3) & 0x0F);
  71                 *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
  72                     temp;
  73
  74                 /* Issue the read command
  75                  * (at this moment all other parameters are 0
  76                  * (size = 1 byte, lane = 0)
  77                  */
  78
  79                 *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
  80                     (I2C_CNTRL2_START);
  81
  82                 /* Wait until operation completed */
  83                 do {
  84                         /* Read I2C operation status */
  85                         temp = *(u32 *) (CFG_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  86
  87                         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START))) {
  88                                 if (0 == (temp &
  89                                      (I2C_CNTRL2_I2C_CFGERR |
  90                                       I2C_CNTRL2_I2C_TO_ERR))
  91                                     ) {
  92                                         op_status = TSI108_I2C_SUCCESS;
  93
  94                                         temp = *(u32 *) (CFG_TSI108_CSR_BASE +
  95                                                          chan_offset +
  96                                                          I2C_RD_DATA);
  97
  98                                         *buffer = (u8) (temp & 0xFF);
  99                                 } else {
 100                                         /* report HW error */
 101                                         op_status = TSI108_I2C_IF_ERROR;
 102
 103                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 104                                 }
 105
 106                                 break;
 107                         }
 108                 } while (to_count--);
 109         } else {
 110                 op_status = TSI108_I2C_IF_BUSY;
 111
 112                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 113         }
 114
 115         DPRINT (("I2C read_byte() status: 0x%02x\n", op_status));
 116         return op_status;
 117 }
 118
 119 /*
 120  * I2C Read interface as defined in "include/i2c.h" :
 121  *   chip_addr: I2C chip address, range 0..127
 122  *                  (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
 123  *              NOTE: The bit 7 in the chip_addr serves as a channel select.
 124  *              This hack is for enabling "isdram" command on Tsi108 boards
 125  *              without changes to common code. Used for I2C reads only.
 126  *   byte_addr: Memory or register address within the chip
 127  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 128  *              memories, 0 for register type devices with only one
 129  *              register)
 130  *   buffer:    Pointer to destination buffer for data to be read
 131  *   len:       How many bytes to read
 132  *
 133  *   Returns: 0 on success, not 0 on failure
 134  */
 135
 136 int i2c_read (uchar chip_addr, uint byte_addr, int alen,
 137                 uchar * buffer, int len)
 138 {
 139         u32 op_status = TSI108_I2C_PARAM_ERR;
 140         u32 i2c_if = 0;
 141
 142         /* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
 143         if (0xD0 == (chip_addr & ~0x07)) {
 144                 i2c_if = 1;
 145                 chip_addr &= 0x7F;
 146         }
 147         /* Check for valid I2C address */
 148         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 149                 while (len--) {
 150                         op_status = i2c_read_byte(i2c_if, chip_addr, byte_addr++, buffer++);
 151
 152                         if (TSI108_I2C_SUCCESS != op_status) {
 153                                 DPRINT (("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
 154
 155                                 break;
 156                         }
 157                 }
 158         }
 159
 160         DPRINT (("I2C read() status: 0x%02x\n", op_status));
 161         return op_status;
 162 }
 163
 164 /* I2C write helper function */
 165
 166 static int i2c_write_byte (uchar chip_addr,/* I2C device address on the bus */
 167                           uint byte_addr, /* Byte address within I2C device */
 168                           uchar * buffer  /*  pointer to data buffer */
 169                           )
 170 {
 171         u32 temp;
 172         u32 to_count = I2C_DELAY;
 173         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
 174
 175         /* Check if I2C operation is in progress */
 176         temp = *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 177
 178         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 179                 /* Place data into the I2C Tx Register */
 180                 *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 181                           I2C_TX_DATA) = (u32) * buffer;
 182
 183                 /* Set device address and operation  */
 184                 temp =
 185                     I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
 186                     ((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
 187                 *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 188                           I2C_CNTRL1) = temp;
 189
 190                 /* Issue the write command (at this moment all other parameters
 191                  * are 0 (size = 1 byte, lane = 0)
 192                  */
 193
 194                 *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 195                           I2C_CNTRL2) = (I2C_CNTRL2_START);
 196
 197                 op_status = TSI108_I2C_TIMEOUT_ERR;
 198
 199                 /* Wait until operation completed */
 200                 do {
 201                         /* Read I2C operation status */
 202                         temp = *(u32 *) (CFG_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 203
 204                         if (0 == (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 205                                 if (0 == (temp &
 206                                      (I2C_CNTRL2_I2C_CFGERR |
 207                                       I2C_CNTRL2_I2C_TO_ERR))) {
 208                                         op_status = TSI108_I2C_SUCCESS;
 209                                 } else {
 210                                         /* report detected HW error */
 211                                         op_status = TSI108_I2C_IF_ERROR;
 212
 213                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 214                                 }
 215
 216                                 break;
 217                         }
 218
 219                 } while (to_count--);
 220         } else {
 221                 op_status = TSI108_I2C_IF_BUSY;
 222
 223                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 224         }
 225
 226         return op_status;
 227 }
 228
 229 /*
 230  * I2C Write interface as defined in "include/i2c.h" :
 231  *   chip_addr: I2C chip address, range 0..127
 232  *   byte_addr: Memory or register address within the chip
 233  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 234  *              memories, 0 for register type devices with only one
 235  *              register)
 236  *   buffer:    Pointer to data to be written
 237  *   len:       How many bytes to write
 238  *
 239  *   Returns: 0 on success, not 0 on failure
 240  */
 241
 242 int i2c_write (uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
 243               int len)
 244 {
 245         u32 op_status = TSI108_I2C_PARAM_ERR;
 246
 247         /* Check for valid I2C address */
 248         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 249                 while (len--) {
 250                         op_status =
 251                             i2c_write_byte (chip_addr, byte_addr++, buffer++);
 252
 253                         if (TSI108_I2C_SUCCESS != op_status) {
 254                                 DPRINT (("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
 255
 256                                 break;
 257                         }
 258                 }
 259         }
 260
 261         return op_status;
 262 }
 263
 264 /*
 265  * I2C interface function as defined in "include/i2c.h".
 266  * Probe the given I2C chip address by reading single byte from offset 0.
 267  * Returns 0 if a chip responded, not 0 on failure.
 268  */
 269
 270 int i2c_probe (uchar chip)
 271 {
 272         u32 tmp;
 273
 274         /*
 275          * Try to read the first location of the chip.
 276          * The Tsi108 HW doesn't support sending just the chip address
 277          * and checkong for an <ACK> back.
 278          */
 279         return i2c_read (chip, 0, 1, (uchar *)&tmp, 1);
 280 }
 281
 282 #endif
 283 #endif /* CONFIG_TSI108_I2C */