dc4a6b828e
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7304 a1c6a512-1295-4272-9138-f99709370657
176 lines
4 KiB
C
176 lines
4 KiB
C
/***************************************************************************
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* __________ __ ___.
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* Open \______ \ ____ ____ | | _\_ |__ _______ ___
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* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
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* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
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* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
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* \/ \/ \/ \/ \/
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* $Id$
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*
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* Copyright (C) 2005 by Andy Young
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*
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* All files in this archive are subject to the GNU General Public License.
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* See the file COPYING in the source tree root for full license agreement.
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*
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* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
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* KIND, either express or implied.
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*
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****************************************************************************/
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#include "cpu.h"
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#include "kernel.h"
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#include "debug.h"
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#include "system.h"
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#include "i2c-coldfire.h"
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#define I2C_DEVICE_1 ((volatile unsigned char *)&MADR)
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#define I2C_DEVICE_2 ((volatile unsigned char *)&MADR2)
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/* Local functions definitions */
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static int i2c_write_byte(int device, unsigned char data);
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static int i2c_gen_start(int device);
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static void i2c_gen_stop(int device);
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static volatile unsigned char *i2c_get_addr(int device);
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/* Public functions */
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void i2c_init(void)
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{
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/* I2C Clock divisor = 576 => 119.952 MHz / 2 / 576 = 104.125 kHz */
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MFDR = 0x14;
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MFDR2 = 0x14;
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#if (CONFIG_KEYPAD == IRIVER_H100_PAD) || (CONFIG_KEYPAD == IRIVER_H300_PAD)
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/* Audio Codec */
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MBDR = 0; /* iRiver firmware does this */
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MBCR = IEN; /* Enable interface */
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#if 0
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/* FM Tuner */
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MBDR2 = 0;
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MBCR2 = IEN;
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#endif
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#endif
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}
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void i2c_close(void)
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{
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MBCR = 0;
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MBCR2 = 0;
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}
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/**
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* Writes bytes to the selected device.
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*
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* Use device=1 for bus 1 at 0x40000280
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* Use device=2 for bus 2 at 0x80000440
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*
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* Returns number of bytes successfully send or -1 if START failed
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*/
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int i2c_write(int device, unsigned char *buf, int count)
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{
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int i;
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int rc;
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rc = i2c_gen_start(device);
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if (rc < 0)
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{
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DEBUGF("i2c: gen_start failed (d=%d)", device);
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return rc*10 - 1;
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}
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for (i=0; i<count; i++)
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{
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rc = i2c_write_byte(device, buf[i]);
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if (rc < 0)
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{
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DEBUGF("i2c: write failed at (d=%d,i=%d)", device, i);
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return rc*10 - 2;
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}
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}
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i2c_gen_stop(device);
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return count;
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}
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/* Write a byte to the interface, returns 0 on success, -1 otherwise. */
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int i2c_write_byte(int device, unsigned char data)
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{
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volatile unsigned char *regs = i2c_get_addr(device);
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long count = 0;
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regs[O_MBDR] = data; /* Write data byte */
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/* Wait for bus busy */
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while (!(regs[O_MBSR] & IBB) && count < MAX_LOOP)
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{
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yield();
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count++;
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}
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if (count >= MAX_LOOP)
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return -1;
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count = 0;
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/* Wait for interrupt flag */
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while (!(regs[O_MBSR] & IFF) && count < MAX_LOOP)
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{
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yield();
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count++;
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}
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if (count >= MAX_LOOP)
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return -2;
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regs[O_MBSR] &= ~IFF; /* Clear interrupt flag */
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if (!(regs[O_MBSR] & ICF)) /* Check that transfer is complete */
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return -3;
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if (regs[O_MBSR] & RXAK) /* Check that the byte has been ACKed */
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return -4;
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return 0;
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}
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/* Returns 0 on success, -1 on failure */
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int i2c_gen_start(int device)
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{
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volatile unsigned char *regs = i2c_get_addr(device);
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long count = 0;
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/* Wait for bus to become free */
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while ((regs[O_MBSR] & IBB) && (count < MAX_LOOP))
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{
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yield();
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count++;
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}
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if (count >= MAX_LOOP)
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return -1;
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regs[O_MBCR] |= MSTA | MTX; /* Generate START */
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return 0;
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}
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void i2c_gen_stop(int device)
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{
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volatile unsigned char *regs = i2c_get_addr(device);
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regs[O_MBCR] &= ~MSTA; /* Clear MSTA to generate STOP */
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}
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volatile unsigned char *i2c_get_addr(int device)
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{
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if (device == 1)
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return I2C_DEVICE_1;
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return I2C_DEVICE_2;
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}
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