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  * NOTE: This driver should be converted to driver model before June 2017.
   8  * Please see doc/driver-model/i2c-howto.txt for instructions.
   9  */
  10
  11 #include <config.h>
  12 #include <common.h>
  13
  14 #include <tsi108.h>
  15
  16 #if defined(CONFIG_CMD_I2C)
  17
  18 #define I2C_DELAY       100000
  19 #undef  DEBUG_I2C
  20
  21 #ifdef DEBUG_I2C
  22 #define DPRINT(x) printf (x)
  23 #else
  24 #define DPRINT(x)
  25 #endif
  26
  27 /* All functions assume that Tsi108 I2C block is the only master on the bus */
  28 /* I2C read helper function */
  29
  30 void i2c_init(int speed, int slaveaddr)
  31 {
  32         /*
  33          * The TSI108 has a fixed I2C clock rate and doesn't support slave
  34          * operation.  This function only exists as a stub to fit into the
  35          * U-Boot I2C API.
  36          */
  37 }
  38
  39 static int i2c_read_byte (
  40                 uint i2c_chan,  /* I2C channel number: 0 - main, 1 - SDC SPD */
  41                 uchar chip_addr,/* I2C device address on the bus */
  42                 uint byte_addr, /* Byte address within I2C device */
  43                 uchar * buffer  /* pointer to data buffer */
  44                 )
  45 {
  46         u32 temp;
  47         u32 to_count = I2C_DELAY;
  48         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
  49         u32 chan_offset = TSI108_I2C_OFFSET;
  50
  51         DPRINT (("I2C read_byte() %d 0x%02x 0x%02x\n",
  52                 i2c_chan, chip_addr, byte_addr));
  53
  54         if (0 != i2c_chan)
  55                 chan_offset = TSI108_I2C_SDRAM_OFFSET;
  56
  57         /* Check if I2C operation is in progress */
  58         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  59
  60         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS |
  61                           I2C_CNTRL2_START))) {
  62                 /* Set device address and operation (read = 0) */
  63                 temp = (byte_addr << 16) | ((chip_addr & 0x07) << 8) |
  64                     ((chip_addr >> 3) & 0x0F);
  65                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL1) =
  66                     temp;
  67
  68                 /* Issue the read command
  69                  * (at this moment all other parameters are 0
  70                  * (size = 1 byte, lane = 0)
  71                  */
  72
  73                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2) =
  74                     (I2C_CNTRL2_START);
  75
  76                 /* Wait until operation completed */
  77                 do {
  78                         /* Read I2C operation status */
  79                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + chan_offset + I2C_CNTRL2);
  80
  81                         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_START))) {
  82                                 if (0 == (temp &
  83                                      (I2C_CNTRL2_I2C_CFGERR |
  84                                       I2C_CNTRL2_I2C_TO_ERR))
  85                                     ) {
  86                                         op_status = TSI108_I2C_SUCCESS;
  87
  88                                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE +
  89                                                          chan_offset +
  90                                                          I2C_RD_DATA);
  91
  92                                         *buffer = (u8) (temp & 0xFF);
  93                                 } else {
  94                                         /* report HW error */
  95                                         op_status = TSI108_I2C_IF_ERROR;
  96
  97                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
  98                                 }
  99
 100                                 break;
 101                         }
 102                 } while (to_count--);
 103         } else {
 104                 op_status = TSI108_I2C_IF_BUSY;
 105
 106                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 107         }
 108
 109         DPRINT (("I2C read_byte() status: 0x%02x\n", op_status));
 110         return op_status;
 111 }
 112
 113 /*
 114  * I2C Read interface as defined in "include/i2c.h" :
 115  *   chip_addr: I2C chip address, range 0..127
 116  *                  (to read from SPD channel EEPROM use (0xD0 ... 0xD7)
 117  *              NOTE: The bit 7 in the chip_addr serves as a channel select.
 118  *              This hack is for enabling "i2c sdram" command on Tsi108 boards
 119  *              without changes to common code. Used for I2C reads only.
 120  *   byte_addr: Memory or 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:    Pointer to destination buffer for data to be read
 125  *   len:       How many bytes to read
 126  *
 127  *   Returns: 0 on success, not 0 on failure
 128  */
 129
 130 int i2c_read (uchar chip_addr, uint byte_addr, int alen,
 131                 uchar * buffer, int len)
 132 {
 133         u32 op_status = TSI108_I2C_PARAM_ERR;
 134         u32 i2c_if = 0;
 135
 136         /* Hack to support second (SPD) I2C controller (SPD EEPROM read only).*/
 137         if (0xD0 == (chip_addr & ~0x07)) {
 138                 i2c_if = 1;
 139                 chip_addr &= 0x7F;
 140         }
 141         /* Check for valid I2C address */
 142         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 143                 while (len--) {
 144                         op_status = i2c_read_byte(i2c_if, chip_addr, byte_addr++, buffer++);
 145
 146                         if (TSI108_I2C_SUCCESS != op_status) {
 147                                 DPRINT (("I2C read_byte() failed: 0x%02x (%d left)\n", op_status, len));
 148
 149                                 break;
 150                         }
 151                 }
 152         }
 153
 154         DPRINT (("I2C read() status: 0x%02x\n", op_status));
 155         return op_status;
 156 }
 157
 158 /* I2C write helper function */
 159
 160 static int i2c_write_byte (uchar chip_addr,/* I2C device address on the bus */
 161                           uint byte_addr, /* Byte address within I2C device */
 162                           uchar * buffer  /*  pointer to data buffer */
 163                           )
 164 {
 165         u32 temp;
 166         u32 to_count = I2C_DELAY;
 167         u32 op_status = TSI108_I2C_TIMEOUT_ERR;
 168
 169         /* Check if I2C operation is in progress */
 170         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 171
 172         if (0 == (temp & (I2C_CNTRL2_RD_STATUS | I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 173                 /* Place data into the I2C Tx Register */
 174                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 175                           I2C_TX_DATA) = (u32) * buffer;
 176
 177                 /* Set device address and operation  */
 178                 temp =
 179                     I2C_CNTRL1_I2CWRITE | (byte_addr << 16) |
 180                     ((chip_addr & 0x07) << 8) | ((chip_addr >> 3) & 0x0F);
 181                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 182                           I2C_CNTRL1) = temp;
 183
 184                 /* Issue the write command (at this moment all other parameters
 185                  * are 0 (size = 1 byte, lane = 0)
 186                  */
 187
 188                 *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET +
 189                           I2C_CNTRL2) = (I2C_CNTRL2_START);
 190
 191                 op_status = TSI108_I2C_TIMEOUT_ERR;
 192
 193                 /* Wait until operation completed */
 194                 do {
 195                         /* Read I2C operation status */
 196                         temp = *(u32 *) (CONFIG_SYS_TSI108_CSR_BASE + TSI108_I2C_OFFSET + I2C_CNTRL2);
 197
 198                         if (0 == (temp & (I2C_CNTRL2_WR_STATUS | I2C_CNTRL2_START))) {
 199                                 if (0 == (temp &
 200                                      (I2C_CNTRL2_I2C_CFGERR |
 201                                       I2C_CNTRL2_I2C_TO_ERR))) {
 202                                         op_status = TSI108_I2C_SUCCESS;
 203                                 } else {
 204                                         /* report detected HW error */
 205                                         op_status = TSI108_I2C_IF_ERROR;
 206
 207                                         DPRINT (("I2C HW error reported: 0x%02x\n", temp));
 208                                 }
 209
 210                                 break;
 211                         }
 212
 213                 } while (to_count--);
 214         } else {
 215                 op_status = TSI108_I2C_IF_BUSY;
 216
 217                 DPRINT (("I2C Transaction start failed: 0x%02x\n", temp));
 218         }
 219
 220         return op_status;
 221 }
 222
 223 /*
 224  * I2C Write interface as defined in "include/i2c.h" :
 225  *   chip_addr: I2C chip address, range 0..127
 226  *   byte_addr: Memory or register address within the chip
 227  *   alen:      Number of bytes to use for addr (typically 1, 2 for larger
 228  *              memories, 0 for register type devices with only one
 229  *              register)
 230  *   buffer:    Pointer to data to be written
 231  *   len:       How many bytes to write
 232  *
 233  *   Returns: 0 on success, not 0 on failure
 234  */
 235
 236 int i2c_write (uchar chip_addr, uint byte_addr, int alen, uchar * buffer,
 237               int len)
 238 {
 239         u32 op_status = TSI108_I2C_PARAM_ERR;
 240
 241         /* Check for valid I2C address */
 242         if (chip_addr <= 0x7F && (byte_addr + len) <= (0x01 << (alen * 8))) {
 243                 while (len--) {
 244                         op_status =
 245                             i2c_write_byte (chip_addr, byte_addr++, buffer++);
 246
 247                         if (TSI108_I2C_SUCCESS != op_status) {
 248                                 DPRINT (("I2C write_byte() failed: 0x%02x (%d left)\n", op_status, len));
 249
 250                                 break;
 251                         }
 252                 }
 253         }
 254
 255         return op_status;
 256 }
 257
 258 /*
 259  * I2C interface function as defined in "include/i2c.h".
 260  * Probe the given I2C chip address by reading single byte from offset 0.
 261  * Returns 0 if a chip responded, not 0 on failure.
 262  */
 263
 264 int i2c_probe (uchar chip)
 265 {
 266         u32 tmp;
 267
 268         /*
 269          * Try to read the first location of the chip.
 270          * The Tsi108 HW doesn't support sending just the chip address
 271          * and checkong for an <ACK> back.
 272          */
 273         return i2c_read (chip, 0, 1, (uchar *)&tmp, 1);
 274 }
 275
 276 #endif