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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
*
* $Id$
*
* Copyright (C) 2005 by Andy Young
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "cpu.h"
#include "kernel.h"
#include "logf.h"
#include "system.h"
#include "i2c-coldfire.h"
/* --- Local functions - declarations --- */
static int i2c_start(volatile unsigned char *iface);
static int i2c_wait_for_slave(volatile unsigned char *iface);
static int i2c_outb(volatile unsigned char *iface, unsigned char byte);
static inline void i2c_stop(volatile unsigned char *iface);
/* --- Public functions - implementation --- */
void i2c_init(void)
{
#ifdef IRIVER_H100_SERIES
/* The FM chip has no pullup for SCL, so we have to bit-bang the
I2C for that one. */
or_l(0x00800000, &GPIO1_OUT);
or_l(0x00000008, &GPIO_OUT);
or_l(0x00800000, &GPIO1_ENABLE);
or_l(0x00000008, &GPIO_ENABLE);
or_l(0x00800000, &GPIO1_FUNCTION);
or_l(0x00000008, &GPIO_FUNCTION);
#elif defined(IRIVER_H300_SERIES)
/* The FM chip has no pullup for SCL, so we have to bit-bang the
I2C for that one. */
or_l(0x03000000, &GPIO1_OUT);
or_l(0x03000000, &GPIO1_ENABLE);
or_l(0x03000000, &GPIO1_FUNCTION);
#endif
/* I2C Clock divisor = 160 => 124.1556 MHz / 2 / 160 = 388.08 kHz */
MFDR = 0x0d;
#if defined(IAUDIO_M3)
MBCR = IEN; /* Enable interface 1 */
/* secondary channel is handled in the interrupt driven ADC driver */
#elif defined(IAUDIO_X5) || defined(IAUDIO_M5)
MBCR = IEN; /* Enable interface 1 */
MFDR2 = 0x0d;
MBCR2 = IEN; /* Enable interface 2 */
#elif defined(IRIVER_H100_SERIES) || defined(IRIVER_H300_SERIES)
MBDR = 0; /* iRiver firmware does this */
MBCR = IEN; /* Enable interface */
#endif
}
void i2c_close(void)
{
MBCR = 0;
MBCR2 = 0;
}
/* End I2C session on the given interface. */
static inline void i2c_stop(volatile unsigned char *iface)
{
iface[O_MBCR] &= ~MSTA;
}
/*
* Writes bytes to a I2C device.
*
* Returns number of bytes successfully sent or a negative value on error.
*/
int i2c_write(volatile unsigned char *iface, unsigned char addr,
const unsigned char *buf, int count)
{
int i, rc;
if (count <= 0)
return 0;
rc = i2c_start(iface);
if (rc < 0)
return rc;
rc = i2c_outb(iface, addr & 0xfe);
if (rc < 0)
return rc;
for (i = 0; i < count; i++)
{
rc = i2c_outb(iface, *buf++);
if (rc < 0)
return rc;
}
i2c_stop(iface);
return count;
}
/*
* Reads bytes from a I2C device.
*
* Returns number of bytes successfully received or a negative value on error.
*/
int i2c_read(volatile unsigned char *iface, unsigned char addr,
unsigned char *buf, int count)
{
int i, rc;
if (count <= 0)
return 0;
rc = i2c_start(iface);
if (rc < 0)
return rc;
rc = i2c_outb(iface, addr | 1);
if (rc < 0)
return rc;
/* Switch to Rx mode */
iface[O_MBCR] &= ~MTX;
/* Turn on ACK generation if reading multiple bytes */
if (count > 1)
iface[O_MBCR] &= ~TXAK;
/* Dummy read */
rc = (int) iface[O_MBDR];
for (i = count; i > 0; i--)
{
rc = i2c_wait_for_slave(iface);
if (rc < 0)
return rc;
if (i == 2)
/* Don't ACK the last byte to be read from the slave */
iface[O_MBCR] |= TXAK;
else if (i == 1)
/* Generate STOP before reading last byte received */
i2c_stop(iface);
*buf++ = iface[O_MBDR];
}
return count;
}
/* --- Local functions - implementation --- */
/* Begin I2C session on the given interface.
*
* Returns 0 on success, negative value on error.
*/
int i2c_start(volatile unsigned char *iface)
{
/* Wait for bus to become free */
int j = MAX_LOOP;
while (--j && (iface[O_MBSR] & IBB))
;
if (!j)
{
logf("i2c: bus is busy (iface=%08lX)", (uintptr_t)iface);
return -1;
}
/* Generate START and prepare for write */
iface[O_MBCR] |= (MSTA | TXAK | MTX);
return 0;
}
/* Wait for slave to act on given I2C interface.
*
* Returns 0 on success, negative value on error.
*/
int i2c_wait_for_slave(volatile unsigned char *iface)
{
int j = MAX_LOOP;
while (--j && ! (iface[O_MBSR] & IIF))
;
if (!j)
{
logf("i2c: IIF not set (iface=%08lX)", (uintptr_t)iface);
i2c_stop(iface);
return -2;
}
/* Clear interrupt flag */
iface[O_MBSR] &= ~IIF;
return 0;
}
/* Write the given byte to the given I2C interface.
*
* Returns 0 on success, negative value on error.
*/
int i2c_outb(volatile unsigned char *iface, unsigned char byte)
{
int rc;
iface[O_MBDR] = byte;
rc = i2c_wait_for_slave(iface);
if (rc < 0)
return rc;
/* Check that transfer is complete */
if ( !(iface[O_MBSR] & ICF))
{
logf("i2c: transfer error (iface=%08lX)", (uintptr_t)iface);
i2c_stop(iface);
return -3;
}
/* Check that the byte has been ACKed */
if (iface[O_MBSR] & RXAK)
{
logf("i2c: no ACK (iface=%08lX)", (uintptr_t)iface);
i2c_stop(iface);
return -4;
}
return 0;
}
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