drivers/i2c/tsi108_i2c.c

   1 /*
   2  * (C) Copyright 2004 Tundra Semiconductor Corp.
   3  * Author: Alex Bounine
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <config.h>
   9 #include <common.h>
  10
  11 #include <tsi108.h>
  12
  13 #if defined(CONFIG_CMD_I2C)
  14
  15 #define I2C_DELAY       100000
  16 #undef  DEBUG_I2C
  17
  18 #ifdef DEBUG_I2C
  19 #define DPRINT(x) printf (x)
  20 #else
  21 #define DPRINT(x)
  22 #endif
  23
  24 /* All functions assume that Tsi108 I2C block is the only master on the bus */
  25 /* I2C read helper function */
  26
  27 void i2c_init(int speed, int slaveaddr)
  28 {
  29         /*
  30          * The TSI108 has a fixed I2C clock rate and doesn't support slave
  31          * operation.  This function only exists as a stub to fit into the
  32          * U-Boot I2C API.
  33          */
  34 }
  35
  36 static int i2c_read_byte (
  37                 uint i2c_chan,  /* I2C channel number: 0 - main, 1 - SDC SPD */
  38                 uchar chip_addr,/* I2C device address on the bus */
  39                 uint byte_addr, /* Byte address within I2C device */
  40                 uchar * buffer  /* pointer to data buffer */
  41                 )
  42 {
  43         u32 temp;
  44         u32 to_count = I2C_DELAY;
  45         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
  46         u32 chan_offset = TSI108_I2C_OFFSET;
  47
  48         DPRINT (("I2C read_byte() %d 0x%02x 0x%02x\n",
  49                 i2c_chan, chip_addr, byte_addr));
  50
  51         if (0 != i2c_chan)
  52                 chan_offset = TSI108_I2C_SDRAM_OFFSET;
  53
  54         /* Check if I2C operation is in progress */
  55         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  56
  57         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
  58                           I2C_CNTRL2_START))) {
  59                 /* Set device address and operation (read = 0) */
  60                 temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
  61                     ((chip_addr >> 3) & 0x0F);
  62                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
  63                     temp;
  64
  65                 /* Issue the read command
  66                  * (at this moment all other parameters are 0
  67                  * (size = 1 byte, lane = 0)
  68                  */
  69
  70                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
  71                     (I2C_CNTRL2_START);
  72
  73                 /* Wait until operation completed */
  74                 do {
  75                         /* Read I2C operation status */
  76                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  77
  78                         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START))) {
  79                                 if (0 == (temp &
  80                                      (I2C_CNTRL2_I2C_CFGERR |
  81                                       I2C_CNTRL2_I2C_TO_ERR))
  82                                     ) {
  83                                         op_status = TSI108_I2C_SUCCESS;
  84
  85                                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE +
  86                                                          chan_offset +
  87                                                          I2C_RD_DATA);
  88
  89                                         *buffer = (u8) (temp & 0xFF);
  90                                 } else {
  91                                         /* report HW error */
  92                                         op_status = TSI108_I2C_IF_ERROR;
  93
  94                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
  95                                 }
  96
  97                                 break;
  98                         }
  99                 } while (to_count--);
 100         } else {
 101                 op_status = TSI108_I2C_IF_BUSY;
 102
 103                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 104         }
 105
 106         DPRINT (("I2C read_byte() status: 0x%02x\n", op_status));
 107         return op_status;
 108 }
 109
 110 /*
 111  * I2C Read interface as defined in "include/i2c.h" :
 112  *   chip_addr: I2C chip address, range 0..127
 113  *                  (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
 114  *              NOTE: The bit 7 in the chip_addr serves as a channel select.
 115  *              This hack is for enabling "i2c sdram" command on Tsi108 boards
 116  *              without changes to common code. Used for I2C reads only.
 117  *   byte_addr: Memory or register address within the chip
 118  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 119  *              memories, 0 for register type devices with only one
 120  *              register)
 121  *   buffer:    Pointer to destination buffer for data to be read
 122  *   len:       How many bytes to read
 123  *
 124  *   Returns: 0 on success, not 0 on failure
 125  */
 126
 127 int i2c_read (uchar chip_addr, uint byte_addr, int alen,
 128                 uchar * buffer, int len)
 129 {
 130         u32 op_status = TSI108_I2C_PARAM_ERR;
 131         u32 i2c_if = 0;
 132
 133         /* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
 134         if (0xD0 == (chip_addr & ~0x07)) {
 135                 i2c_if = 1;
 136                 chip_addr &= 0x7F;
 137         }
 138         /* Check for valid I2C address */
 139         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 140                 while (len--) {
 141                         op_status = i2c_read_byte(i2c_if, chip_addr, byte_addr++, buffer++);
 142
 143                         if (TSI108_I2C_SUCCESS != op_status) {
 144                                 DPRINT (("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
 145
 146                                 break;
 147                         }
 148                 }
 149         }
 150
 151         DPRINT (("I2C read() status: 0x%02x\n", op_status));
 152         return op_status;
 153 }
 154
 155 /* I2C write helper function */
 156
 157 static int i2c_write_byte (uchar chip_addr,/* I2C device address on the bus */
 158                           uint byte_addr, /* Byte address within I2C device */
 159                           uchar * buffer  /*  pointer to data buffer */
 160                           )
 161 {
 162         u32 temp;
 163         u32 to_count = I2C_DELAY;
 164         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
 165
 166         /* Check if I2C operation is in progress */
 167         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 168
 169         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 170                 /* Place data into the I2C Tx Register */
 171                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 172                           I2C_TX_DATA) = (u32) * buffer;
 173
 174                 /* Set device address and operation  */
 175                 temp =
 176                     I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
 177                     ((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
 178                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 179                           I2C_CNTRL1) = temp;
 180
 181                 /* Issue the write command (at this moment all other parameters
 182                  * are 0 (size = 1 byte, lane = 0)
 183                  */
 184
 185                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 186                           I2C_CNTRL2) = (I2C_CNTRL2_START);
 187
 188                 op_status = TSI108_I2C_TIMEOUT_ERR;
 189
 190                 /* Wait until operation completed */
 191                 do {
 192                         /* Read I2C operation status */
 193                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 194
 195                         if (0 == (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 196                                 if (0 == (temp &
 197                                      (I2C_CNTRL2_I2C_CFGERR |
 198                                       I2C_CNTRL2_I2C_TO_ERR))) {
 199                                         op_status = TSI108_I2C_SUCCESS;
 200                                 } else {
 201                                         /* report detected HW error */
 202                                         op_status = TSI108_I2C_IF_ERROR;
 203
 204                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 205                                 }
 206
 207                                 break;
 208                         }
 209
 210                 } while (to_count--);
 211         } else {
 212                 op_status = TSI108_I2C_IF_BUSY;
 213
 214                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 215         }
 216
 217         return op_status;
 218 }
 219
 220 /*
 221  * I2C Write interface as defined in "include/i2c.h" :
 222  *   chip_addr: I2C chip address, range 0..127
 223  *   byte_addr: Memory or register address within the chip
 224  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 225  *              memories, 0 for register type devices with only one
 226  *              register)
 227  *   buffer:    Pointer to data to be written
 228  *   len:       How many bytes to write
 229  *
 230  *   Returns: 0 on success, not 0 on failure
 231  */
 232
 233 int i2c_write (uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
 234               int len)
 235 {
 236         u32 op_status = TSI108_I2C_PARAM_ERR;
 237
 238         /* Check for valid I2C address */
 239         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 240                 while (len--) {
 241                         op_status =
 242                             i2c_write_byte (chip_addr, byte_addr++, buffer++);
 243
 244                         if (TSI108_I2C_SUCCESS != op_status) {
 245                                 DPRINT (("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
 246
 247                                 break;
 248                         }
 249                 }
 250         }
 251
 252         return op_status;
 253 }
 254
 255 /*
 256  * I2C interface function as defined in "include/i2c.h".
 257  * Probe the given I2C chip address by reading single byte from offset 0.
 258  * Returns 0 if a chip responded, not 0 on failure.
 259  */
 260
 261 int i2c_probe (uchar chip)
 262 {
 263         u32 tmp;
 264
 265         /*
 266          * Try to read the first location of the chip.
 267          * The Tsi108 HW doesn't support sending just the chip address
 268          * and checkong for an <ACK> back.
 269          */
 270         return i2c_read (chip, 0, 1, (uchar *)&tmp, 1);
 271 }
 272
 273 #endif