board/eltec/elppc/mpc107_i2c.c

   1 /*
   2  * (C) Copyright 2002 ELTEC Elektronik AG
   3  * Frank Gottschling <fgottschling@eltec.de>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /* includes */
   9 #include <common.h>
  10 #include "srom.h"
  11
  12 /* locals */
  13 static unsigned long mpc107_eumb_addr = 0;
  14
  15 /*----------------------------------------------------------------------------*/
  16
  17 /*
  18  * calculate checksum for ELTEC revision srom
  19  */
  20 unsigned long el_srom_checksum (ptr, size)
  21 register unsigned char *ptr;
  22 unsigned long size;
  23 {
  24     u_long f, accu = 0;
  25     u_int  i;
  26     u_char byte;
  27
  28     for (; size; size--)
  29     {
  30         byte = *ptr++;
  31         for (i = 8; i; i--)
  32         {
  33             f =  ((byte & 1) ^ (accu & 1)) ? 0x84083001 : 0;
  34             accu >>= 1; accu ^= f;
  35             byte >>= 1;
  36         }
  37     }
  38     return(accu);
  39 }
  40
  41 /*----------------------------------------------------------------------------*/
  42
  43 static int mpc107_i2c_wait ( unsigned long timeout )
  44 {
  45     unsigned long x;
  46
  47     while (((x = in32r(MPC107_I2CSR)) & 0x82) != 0x82)
  48     {
  49         if (!timeout--)
  50             return -1;
  51     }
  52
  53     if (x & 0x10)
  54     {
  55         return -1;
  56     }
  57     out32r(MPC107_I2CSR, 0);
  58
  59     return 0;
  60 }
  61
  62 /*----------------------------------------------------------------------------*/
  63
  64 static int mpc107_i2c_wait_idle ( unsigned long timeout )
  65 {
  66     while (in32r(MPC107_I2CSR) & 0x20)
  67     {
  68         if (!timeout--)
  69             return -1;
  70     }
  71     return 0;
  72 }
  73
  74
  75 /*----------------------------------------------------------------------------*/
  76
  77 int mpc107_i2c_read_byte (
  78     unsigned char device,
  79     unsigned char block,
  80     unsigned char offset )
  81 {
  82     unsigned long timeout = MPC107_I2C_TIMEOUT;
  83     int data;
  84
  85     if (!mpc107_eumb_addr)
  86         return -6;
  87
  88     mpc107_i2c_wait_idle (timeout);
  89
  90     /* Start with MEN */
  91     out32r(MPC107_I2CCR, 0x80);
  92
  93     /* Start as master */
  94     out32r(MPC107_I2CCR, 0xB0);
  95     out32r(MPC107_I2CDR, (0xA0 | device | block));
  96
  97     if (mpc107_i2c_wait(timeout) < 0)
  98     {
  99         printf("mpc107_i2c_read Error 1\n");
 100         return -2;
 101     }
 102
 103     if (in32r(MPC107_I2CSR)&0x1)
 104     {
 105         /* Generate STOP condition; device busy or not existing */
 106         out32r(MPC107_I2CCR, 0x80);
 107         return -1;
 108     }
 109
 110     /* Data address */
 111     out32r(MPC107_I2CDR, offset);
 112
 113     if (mpc107_i2c_wait(timeout) < 0)
 114     {
 115         printf("mpc107_i2c_read Error 2\n");
 116         return -3;
 117     }
 118
 119     /* Switch to read - restart */
 120     out32r(MPC107_I2CCR, 0xB4);
 121     out32r(MPC107_I2CDR, (0xA1 | device | block));
 122
 123     if (mpc107_i2c_wait(timeout) < 0)
 124     {
 125         printf("mpc107_i2c_read Error 3\n");
 126         return -4;
 127     }
 128
 129     out32r(MPC107_I2CCR, 0xA8); /* no ACK */
 130     in32r(MPC107_I2CDR);
 131
 132     if (mpc107_i2c_wait(timeout) < 0)
 133     {
 134         printf("mpc107_i2c_read Error 4\n");
 135         return -5;
 136     }
 137     /* Generate STOP condition */
 138     out32r(MPC107_I2CCR, 0x88);
 139
 140     /* read */
 141     data = in32r(MPC107_I2CDR);
 142
 143     return (data);
 144 }
 145
 146 /*----------------------------------------------------------------------------*/
 147
 148 int mpc107_i2c_write_byte (
 149     unsigned char device,
 150     unsigned char block,
 151     unsigned char offset,
 152     unsigned char val )
 153 {
 154
 155     unsigned long timeout = MPC107_I2C_TIMEOUT;
 156
 157     if (!mpc107_eumb_addr)
 158         return -6;
 159
 160     mpc107_i2c_wait_idle(timeout);
 161
 162     /* Start with MEN */
 163     out32r(MPC107_I2CCR, 0x80);
 164
 165     /* Start as master */
 166     out32r(MPC107_I2CCR, 0xB0);
 167     out32r(MPC107_I2CDR, (0xA0 | device | block));
 168
 169     if (mpc107_i2c_wait(timeout) < 0)
 170     {
 171         printf("mpc107_i2c_write Error 1\n");
 172         return -1;
 173     }
 174
 175     /* Data address */
 176     out32r(MPC107_I2CDR, offset);
 177
 178     if (mpc107_i2c_wait(timeout) < 0)
 179     {
 180         printf("mpc107_i2c_write Error 2\n");
 181         return -1;
 182     }
 183
 184     /* Write */
 185     out32r(MPC107_I2CDR, val);
 186     if (mpc107_i2c_wait(timeout) < 0)
 187     {
 188         printf("mpc107_i2c_write Error 3\n");
 189         return -1;
 190     }
 191
 192     /* Generate Stop Condition */
 193     out32r(MPC107_I2CCR, 0x80);
 194
 195     /* Return ACK or no ACK */
 196     return (in32r(MPC107_I2CSR) & 0x01);
 197 }
 198
 199 /*----------------------------------------------------------------------------*/
 200
 201 int mpc107_srom_load (
 202     unsigned char addr,
 203     unsigned char *pBuf,
 204     int          cnt,
 205     unsigned char device,
 206     unsigned char block )
 207 {
 208     register int i;
 209     int val;
 210     int timeout;
 211
 212     for (i = 0; i < cnt; i++)
 213     {
 214         timeout=100;
 215         do
 216         {
 217             val = mpc107_i2c_read_byte (device, block, addr);
 218             if (val < -1)
 219             {
 220             printf("i2c_read_error %d at dev %x block %x addr %x\n",
 221                    val, device, block, addr);
 222             return -1;
 223             }
 224             else if (timeout==0)
 225             {
 226                 printf ("i2c_read_error: timeout at dev %x block %x addr %x\n",
 227                         device, block, addr);
 228                 return -1;
 229             }
 230             timeout--;
 231         } while (val == -1); /* if no ack: try again! */
 232
 233         *pBuf++ = (unsigned char)val;
 234         addr++;
 235
 236         if ((addr == 0) && (i != cnt-1))    /* is it the same block ? */
 237         {
 238             if (block == FIRST_BLOCK)
 239                 block = SECOND_BLOCK;
 240             else
 241             {
 242                 printf ("ic2_read_error: read beyond 2. block !\n");
 243                 return -1;
 244             }
 245         }
 246     }
 247     udelay(100000);
 248     return (cnt);
 249 }
 250
 251 /*----------------------------------------------------------------------------*/
 252
 253 int mpc107_srom_store (
 254     unsigned char addr,
 255     unsigned char *pBuf,
 256     int          cnt,
 257     unsigned char device,
 258     unsigned char block )
 259 {
 260     register int i;
 261
 262     for (i = 0; i < cnt; i++)
 263     {
 264         while (mpc107_i2c_write_byte (device,block,addr,*pBuf) == 1);
 265         addr++;
 266         pBuf++;
 267
 268         if ((addr == 0) && (i != cnt-1))     /* is it the same block ? */
 269         {
 270             if (block == FIRST_BLOCK)
 271                 block = SECOND_BLOCK;
 272             else
 273             {
 274                 printf ("ic2_write_error: write beyond 2. block !\n");
 275                 return -1;
 276             }
 277         }
 278     }
 279     udelay(100000);
 280     return(cnt);
 281 }
 282
 283 /*----------------------------------------------------------------------------*/
 284
 285 int mpc107_i2c_init ( unsigned long eumb_addr, unsigned long divider )
 286 {
 287     unsigned long x;
 288
 289     if (eumb_addr)
 290         mpc107_eumb_addr = eumb_addr;
 291     else
 292         return -1;
 293
 294     /* Set I2C clock */
 295     x = in32r(MPC107_I2CFDR) & 0xffffff00;
 296     out32r(MPC107_I2CFDR, (x | divider));
 297
 298     /* Clear arbitration */
 299     out32r(MPC107_I2CSR, 0);
 300
 301     return mpc107_eumb_addr;
 302 }
 303
 304 /*----------------------------------------------------------------------------*/