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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
* Physical interface of the Philips TEA5767 in iriver H10 series
*
* Copyright (C) 2002 by Linus Nielsen Feltzing
*
* All files in this archive are subject to the GNU General Public License.
* See the file COPYING in the source tree root for full license agreement.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
#include "logf.h"
#include "system.h"
/* cute little functions, atomic read-modify-write */
#define SDA_OUTINIT GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_VAL, 0x08)
#define SDA_HI_IN GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_EN, 0x08)
#define SDA_LO_OUT GPIO_SET_BITWISE(GPIOD_OUTPUT_EN, 0x08)
#define SDA (GPIOD_INPUT_VAL & 0x08)
#define SCL_INPUT GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_EN, 0x10)
#define SCL_OUTPUT GPIO_SET_BITWISE(GPIOD_OUTPUT_EN, 0x10)
#define SCL_LO GPIO_CLEAR_BITWISE(GPIOD_OUTPUT_VAL, 0x10)
#define SCL_HI GPIO_SET_BITWISE(GPIOD_OUTPUT_VAL,0x10)
#define SCL (GPIOD_INPUT_VAL & 0x10)
#define DELAY udelay(2)
static void fmradio_i2c_start(void)
{
SCL_HI;
SCL_OUTPUT;
SDA_HI_IN;
SDA_OUTINIT;
DELAY;
SDA_LO_OUT;
DELAY;
SCL_LO;
}
static void fmradio_i2c_stop(void)
{
SDA_LO_OUT;
DELAY;
SCL_HI;
DELAY;
SDA_HI_IN;
}
/* Generate ACK or NACK */
static void fmradio_i2c_ack(bool nack)
{
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can receive the acknowledge. Therefore it forces the clock
low until it is ready. We need to poll the clock line until it goes
high before we release the ack.
In their infinite wisdom, iriver didn't pull up the SCL line, so
we have to drive the SCL high repeatedly to simulate a pullup. */
if (nack)
SDA_HI_IN;
else
SDA_LO_OUT;
DELAY;
SCL_HI;
do
{
SCL_OUTPUT; /* Set the clock to output */
SCL_INPUT; /* Set the clock to input */
DELAY;
}
while(!SCL); /* and wait for the slave to release it */
SCL_OUTPUT;
SCL_LO;
}
static int fmradio_i2c_getack(void)
{
int ret = 1;
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can send the acknowledge. Therefore it forces the clock
low until it is ready. We need to poll the clock line until it goes
high before we read the ack.
In their infinite wisdom, iriver didn't pull up the SCL line, so
we have to drive the SCL high repeatedly to simulate a pullup. */
SDA_HI_IN;
DELAY;
SCL_HI; /* set clock to high */
do
{
SCL_OUTPUT; /* Set the clock to output */
SCL_INPUT; /* Set the clock to input */
DELAY;
}
while(!SCL); /* and wait for the slave to release it */
if (SDA)
ret = 0; /* ack failed */
SCL_OUTPUT;
SCL_LO;
return ret;
}
static void fmradio_i2c_outb(unsigned char byte)
{
int i;
/* clock out each bit, MSB first */
for ( i=0x80; i; i>>=1 ) {
if ( i & byte )
SDA_HI_IN;
else
SDA_LO_OUT;
DELAY;
SCL_HI;
DELAY;
SCL_LO;
DELAY;
}
}
static unsigned char fmradio_i2c_inb(void)
{
int i;
unsigned char byte = 0;
SDA_HI_IN;
/* clock in each bit, MSB first */
for ( i=0x80; i; i>>=1 ) {
DELAY;
SCL_HI;
DELAY;
if ( SDA )
byte |= i;
SCL_LO;
}
return byte;
}
int fmradio_i2c_write(int address, const unsigned char* buf, int count)
{
int i,x=0;
fmradio_i2c_start();
fmradio_i2c_outb(address & 0xfe);
if (fmradio_i2c_getack())
{
for (i=0; i<count; i++)
{
fmradio_i2c_outb(buf[i]);
if (!fmradio_i2c_getack())
{
x=-2;
break;
}
}
}
else
{
logf("fmradio_i2c_write() - no ack\n");
x=-1;
}
fmradio_i2c_stop();
return x;
}
int fmradio_i2c_read(int address, unsigned char* buf, int count)
{
int i,x=0;
fmradio_i2c_start();
fmradio_i2c_outb(address | 1);
if (fmradio_i2c_getack())
{
for (i=count; i>0; i--)
{
*buf++ = fmradio_i2c_inb();
fmradio_i2c_ack(i == 1);
}
}
else
x=-1;
fmradio_i2c_stop();
return x;
}
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