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added more I2C stuff. Low(est) level routines are now completed.

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git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14242 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Rudolf Cornelissen
2005-09-25 19:27:26 +00:00
parent d1d567ab21
commit f4d7a7b4bd
1 changed files with 69 additions and 7 deletions
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src/add-ons/accelerants/nvidia/engine/nv_i2c.c
+69 -7
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@@ -354,21 +354,21 @@ static void TXBit (uint8 BusNR, bool Bit)
/* send out databit */
if (Bit)
{
OutSDA(BusNR, 1);
OutSDA(BusNR, true);
snooze(3);
if (!InSDA(BusNR)) FlagIICError (2);
}
else
{
OutSDA(BusNR, 0);
OutSDA(BusNR, false);
}
/* generate clock pulse */
snooze(6);
OutSCL(BusNR, 1);
OutSCL(BusNR, true);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(6);
OutSCL(BusNR, 0);
OutSCL(BusNR, false);
snooze(6);
}
@@ -377,22 +377,58 @@ static uint8 RXBit (uint8 BusNR)
uint8 Bit = 0;
/* set SDA so input is possible */
OutSDA(BusNR, 1);
OutSDA(BusNR, true);
/* generate clock pulse */
snooze(6);
OutSCL(BusNR, 1);
OutSCL(BusNR, true);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(3);
/* read databit */
if (InSDA(BusNR)) Bit = 1;
/* finish clockpulse */
OutSCL(BusNR, 0);
OutSCL(BusNR, false);
snooze(6);
return Bit;
}
static void bstart (uint8 BusNR)
{
/* make sure SDA is high */
OutSDA(BusNR, true);
snooze(3);
OutSCL(BusNR, true);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(6);
/* clear SDA while SCL set (bus-start condition) */
OutSDA(BusNR, false);
snooze(6);
OutSCL(BusNR, false);
snooze(6);
LOG(4,("I2C: START condition generated on bus %d.\n", BusNR));
}
static void bstop (uint8 BusNR)
{
/* make sure SDA is low */
OutSDA(BusNR, false);
snooze(3);
OutSCL(BusNR, true);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(6);
/* set SDA while SCL set (bus-stop condition) */
OutSDA(BusNR, true);
snooze(3);
if (!InSDA(BusNR)) FlagIICError (4);
snooze(3);
LOG(4,("I2C: STOP condition generated on bus %d.\n", BusNR));
}
static uint8 i2c_readbyte(uint8 BusNR, bool Ack)
{
uint8 cnt, bit, byte = 0;
@@ -415,6 +451,32 @@ static uint8 i2c_readbyte(uint8 BusNR, bool Ack)
return byte;
}
static bool i2c_writebyte (uint8 BusNR, uint8 byte)
{
uint8 cnt;
bool bit;
/* enable access to primary head */
set_crtc_owner(0);
/* write data */
for (cnt = 8; cnt > 0; cnt--)
{
bit = (byte & 0x80);
TXBit (BusNR, bit);
byte <<= 1;
}
/* read acknowledge */
bit = RXBit (BusNR);
if (bit) FlagIICError (3);
LOG(4,("I2C: written byte ($%02x) to bus #%d; status is %d\n",
byte, BusNR, FlagIICError(0)));
return bit;
}
//end rud.
/*-------------------------------------------