board/MAI/AmigaOneG3SE/smbus.c

   1 #include "memio.h"
   2 #include "articiaS.h"
   3
   4 #ifndef FALSE
   5 #define FALSE 0
   6 #endif
   7
   8 #ifndef TRUE
   9 #define TRUE 1
  10 #endif
  11
  12
  13 void sm_write_mode(void)
  14 {
  15     out_byte(0xA539, 0x00);
  16     out_byte(0xA53A, 0x03);
  17 }
  18
  19 void sm_read_mode(void)
  20 {
  21     out_byte(0xA53A, 0x02);
  22     out_byte(0xA539, 0x02);
  23 }
  24
  25 void sm_write_byte(uint8 writeme)
  26 {
  27     int i;
  28     int level;
  29
  30     out_byte(0xA539, 0x00);
  31
  32     level = 0;
  33
  34     for (i=0; i<8; i++)
  35     {
  36         if ((writeme & 0x80) == (level<<7))
  37         {
  38             /* Bit did not change, rewrite strobe */
  39             out_byte(0xA539, level | 0x02);
  40             out_byte(0xA539, level);
  41         }
  42         else
  43         {
  44             /* Bit changed, set bit, then strobe */
  45             level = (writeme & 0x80) >> 7;
  46             out_byte(0xA539, level);
  47             out_byte(0xA539, level | 0x02);
  48             out_byte(0xA539, level);
  49         }
  50         writeme <<= 1;
  51     }
  52     out_byte(0xA539, 0x00);
  53 }
  54
  55 uint8 sm_read_byte(void)
  56 {
  57     uint8 retme, r;
  58     int i;
  59
  60     retme = 0;
  61     for (i=0; i<8; i++)
  62     {
  63         retme <<= 1;
  64         out_byte(0xA539, 0x00);
  65         out_byte(0xA539, 0x02);
  66         r = in_byte(0xA538) & 0x01;
  67         retme |= r;
  68     }
  69
  70     return retme;
  71 }
  72
  73 int sm_get_ack(void)
  74 {
  75     uint8 r;
  76     r = in_byte(0xA538);
  77     if ((r&0x01) == 0) return TRUE;
  78     else return FALSE;
  79 }
  80
  81 void sm_write_ack(void)
  82 {
  83     out_byte(0xA539, 0x00);
  84     out_byte(0xA539, 0x02);
  85     out_byte(0xA539, 0x00);
  86 }
  87
  88 void sm_write_nack(void)
  89 {
  90     out_byte(0xA539, 0x01);
  91     out_byte(0xA539, 0x03);
  92     out_byte(0xA539, 0x01);
  93 }
  94
  95 void sm_send_start(void)
  96 {
  97     out_byte(0xA539, 0x03);
  98     out_byte(0xA539, 0x02);
  99 }
 100
 101 void sm_send_stop(void)
 102 {
 103     out_byte(0xA539, 0x02);
 104     out_byte(0xA539, 0x03);
 105 }
 106
 107 int sm_read_byte_from_device(uint8 addr, uint8 reg, uint8 *storage)
 108 {
 109     /* S Addr Wr */
 110     sm_write_mode();
 111     sm_send_start();
 112     sm_write_byte((addr<<1));
 113
 114     /* [A] */
 115     sm_read_mode();
 116     if (sm_get_ack() == FALSE) return FALSE;
 117
 118     /* Comm */
 119     sm_write_mode();
 120     sm_write_byte(reg);
 121
 122     /* [A] */
 123     sm_read_mode();
 124     if (sm_get_ack() == FALSE) return FALSE;
 125
 126     /* S Addr Rd */
 127     sm_write_mode();
 128     sm_send_start();
 129     sm_write_byte((addr<<1)|1);
 130
 131     /* [A] */
 132     sm_read_mode();
 133     if (sm_get_ack() == FALSE) return FALSE;
 134
 135     /* [Data] */
 136     *storage = sm_read_byte();
 137
 138     /* NA */
 139     sm_write_mode();
 140     sm_write_nack();
 141     sm_send_stop();
 142
 143     return TRUE;
 144 }
 145
 146 void sm_init(void)
 147 {
 148     /* Switch to PMC mode */
 149     pci_write_cfg_byte(0, 0, REG_GROUP, (uint8)(REG_GROUP_SPECIAL|REG_GROUP_POWER));
 150
 151     /* Set GPIO Base */
 152     pci_write_cfg_long(0, 0, 0x40, 0xa500);
 153
 154     /* Enable GPIO */
 155     pci_write_cfg_byte(0, 0, 0x44, 0x11);
 156
 157     /* Set both GPIO 0 and 1 as output */
 158     out_byte(0xA53A, 0x03);
 159 }
 160
 161
 162 void sm_term(void)
 163 {
 164     /* Switch to normal mode */
 165     pci_write_cfg_byte(0, 0, REG_GROUP, 0);
 166 }
 167
 168
 169 int sm_get_data(uint8 *DataArray, int dimm_socket)
 170 {
 171     int j;
 172
 173 #if 0
 174     /* Switch to PMC mode */
 175     pci_write_cfg_byte(0, 0, REG_GROUP, (uint8)(REG_GROUP_SPECIAL|REG_GROUP_POWER));
 176
 177     /* Set GPIO Base */
 178     pci_write_cfg_long(0, 0, 0x40, 0xa500);
 179
 180     /* Enable GPIO */
 181     pci_write_cfg_byte(0, 0, 0x44, 0x11);
 182
 183     /* Set both GPIO 0 and 1 as output */
 184     out_byte(0xA53A, 0x03);
 185 #endif
 186
 187     sm_init();
 188     /* Start reading the rom */
 189
 190     j = 0;
 191
 192     do
 193     {
 194         if (sm_read_byte_from_device(dimm_socket, (uint8)j, DataArray) == FALSE)
 195         {
 196             sm_term();
 197             return FALSE;
 198         }
 199
 200         DataArray++;
 201         j++;
 202     } while (j < 128);
 203
 204     sm_term();
 205     return TRUE;
 206 }