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/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2005 by Andy Young
*
* 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 "cpu.h"
#include "kernel.h"
#include "logf.h"
#include "system.h"
#include "i2c-coldfire.h"
#define I2C_DEVICE_1 ((volatile unsigned char *)&MADR)
#define I2C_DEVICE_2 ((volatile unsigned char *)&MADR2)
/* Local functions definitions */
static int i2c_write_byte(int device, unsigned char data);
static int i2c_gen_start(int device);
static void i2c_gen_stop(int device);
static volatile unsigned char *i2c_get_addr(int device);
/* Public functions */
void i2c_init(void)
{
/* 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);
/* I2C Clock divisor = 576 => 119.952 MHz / 2 / 576 = 104.125 kHz */
MFDR = 0x14;
#if (CONFIG_KEYPAD == IRIVER_H100_PAD) || (CONFIG_KEYPAD == IRIVER_H300_PAD)
/* Audio Codec */
MBDR = 0; /* iRiver firmware does this */
MBCR = IEN; /* Enable interface */
#endif
}
void i2c_close(void)
{
MBCR = 0;
}
/**
* Writes bytes to the selected device.
*
* Use device=1 for bus 1 at 0x40000280
* Use device=2 for bus 2 at 0x80000440
*
* Returns number of bytes successfully send or -1 if START failed
*/
int i2c_write(int device, unsigned char *buf, int count)
{
int i;
int rc;
rc = i2c_gen_start(device);
if (rc < 0)
{
logf("i2c: gen_start failed (d=%d)", device);
return rc*10 - 1;
}
for (i=0; i<count; i++)
{
rc = i2c_write_byte(device, buf[i]);
if (rc < 0)
{
logf("i2c: write failed at (d=%d,i=%d)", device, i);
return rc*10 - 2;
}
}
i2c_gen_stop(device);
return count;
}
/* Write a byte to the interface, returns 0 on success, -1 otherwise. */
int i2c_write_byte(int device, unsigned char data)
{
volatile unsigned char *regs = i2c_get_addr(device);
long count = 0;
regs[O_MBDR] = data; /* Write data byte */
/* Wait for bus busy */
while (!(regs[O_MBSR] & IBB) && count < MAX_LOOP)
{
yield();
count++;
}
if (count >= MAX_LOOP)
return -1;
count = 0;
/* Wait for interrupt flag */
while (!(regs[O_MBSR] & IFF) && count < MAX_LOOP)
{
yield();
count++;
}
if (count >= MAX_LOOP)
return -2;
regs[O_MBSR] &= ~IFF; /* Clear interrupt flag */
if (!(regs[O_MBSR] & ICF)) /* Check that transfer is complete */
return -3;
if (regs[O_MBSR] & RXAK) /* Check that the byte has been ACKed */
return -4;
return 0;
}
/* Returns 0 on success, -1 on failure */
int i2c_gen_start(int device)
{
volatile unsigned char *regs = i2c_get_addr(device);
long count = 0;
/* Wait for bus to become free */
while ((regs[O_MBSR] & IBB) && (count < MAX_LOOP))
{
yield();
count++;
}
if (count >= MAX_LOOP)
return -1;
regs[O_MBCR] |= MSTA | MTX; /* Generate START */
return 0;
}
void i2c_gen_stop(int device)
{
volatile unsigned char *regs = i2c_get_addr(device);
regs[O_MBCR] &= ~MSTA; /* Clear MSTA to generate STOP */
}
volatile unsigned char *i2c_get_addr(int device)
{
if (device == 1)
return I2C_DEVICE_1;
return I2C_DEVICE_2;
}
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