92fed35da6
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21820 a1c6a512-1295-4272-9138-f99709370657
150 lines
3.9 KiB
C
150 lines
3.9 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) 2009 by Bertrik Sikken
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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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 "config.h"
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#include "system.h"
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#include "kernel.h"
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#include "i2c-s5l8700.h"
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/* Driver for the s5l8700 built-in I2C controller in master mode
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Both the i2c_read and i2c_write function take the following arguments:
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* slave, the address of the i2c slave device to read from / write to
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* address, optional sub-address in the i2c slave (unused if -1)
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* len, number of bytes to be transfered
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* data, pointer to data to be transfered
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A return value < 0 indicates an error.
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Note:
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* blocks the calling thread for the entire duraton of the i2c transfer but
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uses wakeup_wait/wakeup_signal to allow other threads to run.
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* ACK from slave is not checked, so functions never return an error
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*/
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static struct mutex i2c_mtx;
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static struct wakeup i2c_wakeup;
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void INT_IIC(void)
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{
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/* disable interrupt (but don't clear it yet) */
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IICCON &= ~((1 << 4) | (1 << 5));
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wakeup_signal(&i2c_wakeup);
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}
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void i2c_init(void)
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{
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mutex_init(&i2c_mtx);
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wakeup_init(&i2c_wakeup);
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/* enable I2C pins */
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PCON10 = (2 << 2) |
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(2 << 0);
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/* enable I2C clock */
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PWRCON &= ~(1 << 5);
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/* initial config */
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IICADD = 0;
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IICCON = (1 << 7) | /* ACK_GEN */
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(1 << 6) | /* CLKSEL = PCLK/512 */
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(1 << 5) | /* INT_EN */
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(1 << 4) | /* IRQ clear */
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(3 << 0); /* CK_REG */
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/* serial output on */
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IICSTAT = (1 << 4);
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/* enable interrupt */
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INTMSK |= (1 << 27);
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}
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int i2c_write(unsigned char slave, int address, int len, const unsigned char *data)
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{
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mutex_lock(&i2c_mtx);
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/* START */
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IICDS = slave & ~1;
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IICSTAT = 0xF0;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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if (address >= 0) {
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/* write address */
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IICDS = address;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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}
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/* write data */
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while (len--) {
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IICDS = *data++;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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}
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/* STOP */
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IICSTAT = 0xD0;
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IICCON = 0xF3;
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while ((IICSTAT & (1 << 5)) != 0);
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mutex_unlock(&i2c_mtx);
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return 0;
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}
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int i2c_read(unsigned char slave, int address, int len, unsigned char *data)
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{
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mutex_lock(&i2c_mtx);
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if (address >= 0) {
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/* START */
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IICDS = slave & ~1;
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IICSTAT = 0xF0;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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/* write address */
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IICDS = address;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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}
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/* (repeated) START */
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IICDS = slave | 1;
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IICSTAT = 0xB0;
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IICCON = 0xF3;
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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while (len--) {
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IICCON = (len == 0) ? 0x73 : 0xF3; /* NACK or ACK */
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wakeup_wait(&i2c_wakeup, TIMEOUT_BLOCK);
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*data++ = IICDS;
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}
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/* STOP */
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IICSTAT = 0x90;
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IICCON = 0xF3;
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while ((IICSTAT & (1 << 5)) != 0);
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mutex_unlock(&i2c_mtx);
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return 0;
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}
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