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S5L8700: implement i2c driver (used for communicating with the RTC and the codec in the meizus) 

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21533 a1c6a512-1295-4272-9138-f99709370657
This commit is contained in:
Bertrik Sikken 2009-06-27 20:11:11 +00:00
parent 660daa51d4
commit c33373e163
3 changed files with 170 additions and 0 deletions
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2
firmware/SOURCES
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@ -358,6 +358,8 @@ target/arm/pnx0101/i2c-pnx0101.c
target/arm/i2c-telechips.c
#elif CONFIG_I2C == I2C_S3C2440
/* no i2c driver yet */
#elif CONFIG_I2C == I2C_S5L8700
target/arm/s5l8700/i2c-s5l8700.c
#endif
#if CONFIG_CPU == PNX0101

32
firmware/export/i2c-s5l8700.h Normal file
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@ -0,0 +1,32 @@
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Bertrik Sikken
*
* 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.
*
****************************************************************************/
#ifndef _I2C_S5l8700_H
#define _I2C_S5l8700_H
#include "config.h"
void i2c_init(void);
int i2c_write(unsigned char slave, int address, int len, const unsigned char *data);
int i2c_read(unsigned char slave, int address, int len, unsigned char *data);
#endif /* _I2C_S5l8700_H */

136
firmware/target/arm/s5l8700/i2c-s5l8700.c Normal file
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@ -0,0 +1,136 @@
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
*
* Copyright (C) 2009 by Bertrik Sikken
*
* 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 "config.h"
#include "system.h"
#include "kernel.h"
#include "i2c-s5l8700.h"
/* Driver for the s5l8700 built-in I2C controller in master mode
Both the i2c_read and i2c_write function take the following arguments:
* slave, the address of the i2c slave device to read from / write to
* address, optional sub-address in the i2c slave (unused if -1)
* len, number of bytes to be transfered
* data, pointer to data to be transfered
A return value < 0 indicates an error.
Known issues:
* uses polled mode (not interrupt driven), just like the OF
* ACK from slave is not checked, so functions never return an error
*/
static struct mutex i2c_mtx;
void i2c_init(void)
{
mutex_init(&i2c_mtx);
/* enable I2C pins */
PCON10 = (2 << 2) |
(2 << 0);
/* enable I2C clock */
PWRCON &= ~(1 << 5);
/* initial config */
IICADD = 0;
IICCON = (1 << 7) | /* ACK_GEN */
(1 << 6) | /* CLKSEL = PCLK/512 */
(1 << 5) | /* INT_EN */
(1 << 4) | /* IRQ clear */
(3 << 0); /* CK_REG */
/* serial output on */
IICSTAT = (1 << 4);
}
int i2c_write(unsigned char slave, int address, int len, const unsigned char *data)
{
mutex_lock(&i2c_mtx);
/* START */
IICDS = slave & ~1;
IICSTAT = 0xF0;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
if (address >= 0) {
/* write address */
IICDS = address;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
}
/* write data */
while (len--) {
IICDS = *data++;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
}
/* STOP */
IICSTAT = 0xD0;
IICCON = 0xF3;
while ((IICSTAT & (1 << 5)) != 0);
mutex_unlock(&i2c_mtx);
return 0;
}
int i2c_read(unsigned char slave, int address, int len, unsigned char *data)
{
mutex_lock(&i2c_mtx);
if (address >= 0) {
/* START */
IICDS = slave & ~1;
IICSTAT = 0xF0;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
/* write address */
IICDS = address;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
}
/* (repeated) START */
IICDS = slave | 1;
IICSTAT = 0xB0;
IICCON = 0xF3;
while ((IICCON & (1 << 4)) == 0);
while (len--) {
IICCON = (len == 0) ? 0x73 : 0xF3; /* NACK or ACK */
while ((IICCON & (1 << 4)) == 0);
*data++ = IICDS;
}
/* STOP */
IICSTAT = 0x90;
IICCON = 0xF3;
while ((IICSTAT & (1 << 5)) != 0);
mutex_unlock(&i2c_mtx);
return 0;
}