spmp-i2c-bitbang-hw.c

REGISTERS:

IO:10009160 ; unsigned __int16 REG_SIF_UNK00
IO:10009160 REG_SIF_UNK00   % 2                     ; DATA XREF: sub_24075C08+4↓o
IO:10009160                                         ; sub_24075C08+104↓r ...
IO:10009162 ; unsigned __int16 REG_SIF_OUTPUT_ENABLE_maybe
IO:10009162 REG_SIF_OUTPUT_ENABLE_maybe % 2         ; DATA XREF: SDRAM:2400064C↓o
IO:10009162                                         ; SDRAM:24000654↓w ...
IO:10009164 ; unsigned __int8 REG_SIF_OUTPUT
IO:10009164 REG_SIF_OUTPUT  % 2                     ; DATA XREF: sub_24075C08+130↓r
IO:10009164                                         ; sub_24075C08+138↓w ...
IO:10009164                                         ; [2] = SCL
IO:10009164                                         ; [3] = SDA
IO:10009166 ; unsigned __int16 REG_SIF_INPUT
IO:10009166 REG_SIF_INPUT   % 2
  
00000004 ; enum SIF_LINE_BITS, mappedto_40, bitfield
00000004 SIF_LINE_SCL     EQU 4
00000008 SIF_LINE_SDA     EQU 8
00000008

/* SDA */
void i2cSetOE_SDA(void)
{
  REG_SIF_UNK00 |= SIF_LINE_SDA;
  REG_SIF_OUTPUT_ENABLE_maybe |= SIF_LINE_SDA;
}

void i2cClrOE_SDA(void)
{
  REG_SIF_UNK00 |= SIF_LINE_SDA;
  REG_SIF_OUTPUT_ENABLE_maybe &= ~SIF_LINE_SDA;
}

bool i2cGetSDA(void)
{
  unsigned __int16 v0; // r3

  v0 = REG_SIF_UNK00;
  REG_SIF_UNK00 = v0 | SIF_LINE_SDA;
  REG_SIF_OUTPUT_ENABLE_maybe &= ~SIF_LINE_SDA;
  return (REG_SIF_INPUT & SIF_LINE_SDA) != 0;
}

void __fastcall i2cDriveSDA(unsigned __int8 sda)
{
  unsigned __int8 v1; // r3

  REG_SIF_UNK00 |= SIF_LINE_SDA;
  REG_SIF_OUTPUT_ENABLE_maybe |= SIF_LINE_SDA;
  if ( sda == 1 )
    v1 = REG_SIF_OUTPUT | SIF_LINE_SDA;
  else
    v1 = REG_SIF_OUTPUT & ~SIF_LINE_SDA;
  REG_SIF_OUTPUT = v1;
}

/* SCL */
void __fastcall i2cDriveSCL(unsigned __int8 scl)
{
  unsigned __int8 v1; // r3

  REG_SIF_UNK00 |= SIF_LINE_SCL;
  REG_SIF_OUTPUT_ENABLE_maybe |= SIF_LINE_SCL;
  if ( scl == 1 )
    v1 = REG_SIF_OUTPUT | SIF_LINE_SCL;
  else
    v1 = REG_SIF_OUTPUT & ~SIF_LINE_SCL;
  REG_SIF_OUTPUT = v1;
}

spmp-i2c-proto.c

void __cdecl i2cStartCondition()
{
  i2cDriveSDA(1u);
  i2cDriveSCL(1u);
  waitClocks7(0x28u);
  i2cDriveSDA(0);
  waitClocks7(0x28u);
  i2cDriveSCL(0);
}

void i2cStopCondition(void)
{
  i2cDriveSDA(0);
  i2cDriveSCL(1u);
  waitClocks7(0x28u);
  i2cDriveSDA(1u);
  waitClocks7(0x28u);
  i2cDriveSCL(0);
}

bool __cdecl i2cTxAck()
{
  bool v0; // r4
  bool v1; // r5

  i2cClrOE_SDA();
  waitClocks7(0x2Du);
  v0 = 0;
  v1 = i2cGetSDA();
  waitClocks7(0x28u);
  i2cSetOE_SDA();
  waitClocks7(0x2Du);
  i2cDriveSDA(0);
  waitClocks7(0x28u);
  i2cDriveSCL(1u);
  waitClocks7(0x28u);
  i2cDriveSCL(0);
  waitClocks7(0x28u);
  if ( v1 )
    oscall_SerialPrint(off_24289158); // "SPMP_IoIIC_Ack_Tx Fail!!\n"
  else
    v0 = 1;
  waitClocks7(0x28u);
  return v0;
}

void i2cRxAck(void)
{
  i2cDriveSDA(0);
  waitClocks7(0x28u);
  i2cDriveSCL(1u);
  waitClocks7(0x28u);
  i2cDriveSCL(0);
  waitClocks7(0x28u);
}

void i2cSendNack_maybe(void)
{
  i2cDriveSDA(1u);
  waitClocks7(0x28u);
  i2cDriveSCL(1u);
  waitClocks7(0x28u);
  i2cDriveSCL(0);
  waitClocks7(0x28u);
  i2cDriveSDA(0);
  waitClocks7(0x28u);
}

void __fastcall i2cSendByte(unsigned __int8 data)
{
  int v1; // r4
  unsigned int v2; // r5
  unsigned __int8 v3; // r0

  v1 = data;
  v2 = 0;
  do
  {
    v3 = 1;
    if ( !(v1 & 0x80) )
      v3 = 0;
    i2cDriveSDA(v3);
    i2cDriveSCL(1u);
    waitClocks7(0x28u);
    v1 = 2 * v1 & 0xFF;
    i2cDriveSCL(0);
    i2cDriveSDA(0);
    waitClocks7(0x28u);
    v2 = (v2 + 1) & 0xFF;
  }
  while ( v2 <= 7 );
}

void __fastcall i2cReadByte(unsigned __int8 *data)
{
  unsigned __int8 *v1; // r7
  unsigned int v2; // r4
  unsigned int v3; // r6
  bool v4; // r5

  v1 = data;
  i2cClrOE_SDA();
  waitClocks7(0x2Du);
  v2 = 0;
  v3 = 0x80;
  *v1 = 0;
  do
  {
    i2cDriveSCL(1u);
    waitClocks7(0x28u);
    v4 = i2cGetSDA();
    waitClocks7(0x28u);
    if ( v4 )
      *v1 |= v3;
    i2cDriveSCL(0);
    waitClocks7(0x28u);
    v2 = (v2 + 1) & 0xFF;
    v3 >>= 1;
  }
  while ( v2 <= 7 );
  i2cSetOE_SDA();
  waitClocks7(0x2Du);
}

void __fastcall BK1080_i2cRead(unsigned __int8 reg, unsigned __int8 *buf, unsigned __int8 len)
{
  int v3; // r4
  unsigned __int8 *v4; // r6
  int v5; // r5
  int v6; // r0
  int v7; // r5
  int v8; // r4

  v3 = len;
  v4 = buf;
  v5 = reg;
  i2cStartCondition();                          // START
  i2cSendByte(0x80u);                           // DEVICE ADDRESS
  i2cTxAck();
  v6 = 2 * v5 & 0xFF | 1;
  v7 = v3 - 1;
  v8 = 0;
  i2cSendByte(v6);                              // REGISTER ADDRESS
  i2cTxAck();
  if ( v7 > 0 )
  {
    do
    {
      i2cReadByte(&v4[v8]);                     // DATA
      i2cRxAck();
      v8 = (v8 + 1) & 0xFF;
    }
    while ( v8 < v7 );
  }
  i2cReadByte(&v4[v8]);
  i2cSendNack_maybe();                          // NACK
  i2cStopCondition();                           // STOP
}

void __fastcall BK1080_i2cWrite(unsigned __int8 address, unsigned __int8 *buffer, unsigned __int8 length)
{
  unsigned int v3; // r4
  unsigned __int8 *v4; // r6
  char v5; // r5
  unsigned __int8 v6; // r0
  unsigned int v7; // r5

  v3 = length;
  v4 = buffer;
  v5 = 2 * address;
  i2cStartCondition();                          // START
  i2cSendByte(0x80u);                           // DEVICE ADDRESS
  i2cTxAck();
  v6 = v5 & 0xFE;
  v7 = 0;
  i2cSendByte(v6);                              // DEVICE REGISTER
  i2cTxAck();
  if ( v3 > 0 )
  {
    do
    {
      i2cSendByte(v4[v7]);                      // DATA
      i2cTxAck();
      v7 = (v7 + 1) & 0xFF;
    }
    while ( v7 < v3 );
  }
  i2cStopCondition();                           // STOP
}