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added I2C routines from BeTVOut (in progress). Starting TVout support (whenever I have a bit of spare time :)

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git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@14237 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Rudolf Cornelissen 2005-09-24 17:55:58 +00:00
parent 53960be31f
commit 6c25f4ae64
1 changed files with 121 additions and 21 deletions
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142
src/add-ons/accelerants/nvidia/engine/nv_i2c.c
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@ -9,7 +9,7 @@
*
* Other authors:
* Mark Watson 6/2000,
* Rudolf Cornelissen 12/2002-12/2003
* Rudolf Cornelissen 12/2002-9/2005
*/
#define MODULE_BIT 0x00004000
@ -25,7 +25,6 @@ void i2c_low(void);
int i2c_get_ack(void);
void i2c_send_ack(void);
int i2c_sendbyte(unsigned char data);
unsigned char i2c_readbyte(int ack_required);
/*which device on the bus is the MAVEN?*/
#define MAVEN_WRITE (0x1B<<1)
@ -263,40 +262,141 @@ int i2c_sendbyte(unsigned char data)
return i2c_get_ack();
}
unsigned char i2c_readbyte(int ack_required)
//rud's betvout:
static char FlagIICError (char ErrNo)
//error code list:
//1 - SCL locked low by device (bus is still busy)
//2 - SDA locked low by device (bus is still busy)
//3 - No Acknowledge from device (no handshake)
//4 - SDA not released for master to generate STOP bit
{
int i;
unsigned char data=0;
/*read data*/
i2c_set_lines(0,1);
for (i=7; i>=0; i--)
{
i2c_set_lines(1,1);
if (i2c_get_data()==1)
data |= (1<<i);
i2c_set_lines(0,1);
}
static char IICError = 0;
/*send acknowledge*/
if (ack_required) i2c_send_ack();
return data;
if (!IICError) IICError = ErrNo;
if (ErrNo == -1) IICError = 0;
return IICError;
}
static void OutSCL(uint8 BusNR, bool Bit)
{
uint8 data;
/* enable access to primary head */
set_crtc_owner(0);
if (BusNR)
{
data = (CRTCR(WR_I2CBUS_1) & 0xf0) | 0x01;
if (Bit)
CRTCW(WR_I2CBUS_1, (data | 0x20));
else
CRTCW(WR_I2CBUS_1, (data & ~0x20));
}
else
{
data = CRTCR(WR_I2CBUS_0) & 0xf0;
if (Bit)
CRTCW(WR_I2CBUS_0, (data | 0x20));
else
CRTCW(WR_I2CBUS_0, (data & ~0x20));
}
}
static void OutSDA(uint8 BusNR, bool Bit)
{
//fixme..
}
static bool InSCL(uint8 BusNR)
{
//fixme..
return 0;
}
static bool InSDA(uint8 BusNR)
{
//fixme..
return 0;
}
static void TXBit (uint8 BusNR, bool Bit)
{
/* send out databit */
if (Bit)
{
OutSDA(BusNR, 1);
snooze(3);
if (!InSDA(BusNR)) FlagIICError (2);
}
else
{
OutSDA(BusNR, 0);
}
/* generate clock pulse */
snooze(6);
OutSCL(BusNR, 1);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(6);
OutSCL(BusNR, 0);
snooze(6);
}
static uint8 RXBit (uint8 BusNR)
{
uint8 Bit = 0;
/* set SDA so input is possible */
OutSDA(BusNR, 1);
/* generate clock pulse */
snooze(6);
OutSCL(BusNR, 1);
snooze(3);
if (!InSCL(BusNR)) FlagIICError (1);
snooze(3);
/* read databit */
if (InSDA(BusNR)) Bit = 1;
/* finish clockpulse */
OutSCL(BusNR, 0);
snooze(6);
return Bit;
}
static uint8 i2c_readbyte(uint8 BusNR, bool Ack)
{
uint8 cnt, bit, byte = 0;
/* read data */
for (cnt = 8; cnt > 0; cnt--)
{
byte <<= 1;
bit = RXBit (BusNR);
byte += bit;
}
/* send acknowledge */
TXBit (BusNR, Ack);
LOG(4,("I2C: read byte ($%02x) from bus #%d; status is %d\n",
byte, BusNR, FlagIICError(0)));
return byte;
}
//end rud.
/*-------------------------------------------
*PUBLIC functions
*/
int i2c_maven_read(unsigned char address)
{
int error=0;
int data;
int data=0;
i2c_start();
{
error+=i2c_sendbyte(MAVEN_READ);
error+=i2c_sendbyte(address);
data = i2c_readbyte(0);
// data = i2c_readbyte(0);
}
i2c_stop();
if (error>0) LOG(8,("I2C: MAVR ERROR - %x\n",error));