fd11471a3f
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@21160 a1c6a512-1295-4272-9138-f99709370657
247 lines
5.2 KiB
C
247 lines
5.2 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 Maurus Cuelenaere
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*
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* based on linux/arch/mips/jz4740/i2c.c
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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 "jz4740.h"
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#include "logf.h"
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/*
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* Jz4740 I2C routines.
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*
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* Copyright (C) 2005,2006 Ingenic Semiconductor Inc.
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* Author: <lhhuang@ingenic.cn>
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*
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* This program is free software; you can distribute it and/or modify it
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* under the terms of the GNU General Public License (Version 2) as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
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*
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*/
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/* I2C protocol */
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#define I2C_READ 1
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#define I2C_WRITE 0
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#define TIMEOUT 1000
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/*
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* I2C bus protocol basic routines
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*/
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static int i2c_put_data(unsigned char data)
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{
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unsigned int timeout = TIMEOUT*10;
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__i2c_write(data);
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__i2c_set_drf();
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while (__i2c_check_drf() != 0);
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while (!__i2c_transmit_ended());
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while (!__i2c_received_ack() && timeout)
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timeout--;
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if (timeout)
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return 0;
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else
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return -1;
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}
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#if 0
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static int i2c_put_data_nack(unsigned char data)
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{
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unsigned int timeout = TIMEOUT*10;
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__i2c_write(data);
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__i2c_set_drf();
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while (__i2c_check_drf() != 0);
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while (!__i2c_transmit_ended());
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while (timeout--);
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return 0;
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}
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#endif
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static int i2c_get_data(unsigned char *data, int ack)
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{
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int timeout = TIMEOUT*10;
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if (!ack)
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__i2c_send_nack();
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else
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__i2c_send_ack();
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while (__i2c_check_drf() == 0 && timeout)
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timeout--;
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if (timeout)
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{
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if (!ack)
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__i2c_send_stop();
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*data = __i2c_read();
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__i2c_clear_drf();
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return 0;
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}
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else
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return -1;
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}
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void i2c_setclk(unsigned int i2cclk)
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{
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__i2c_set_clk(__cpm_get_i2sclk(), i2cclk);
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}
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/*
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* I2C interface
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*/
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static void i2c_open(void)
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{
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i2c_setclk(10000); /* default 10 KHz */
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__i2c_enable();
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}
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static void i2c_close(void)
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{
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udelay(300); /* wait for STOP goes over. */
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__i2c_disable();
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}
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int i2c_read(int device, unsigned char *buf, int count)
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{
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int cnt = count;
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int timeout = 5;
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device &= 0xFF;
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i2c_open();
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L_try_again:
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if (timeout < 0)
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goto L_timeout;
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__i2c_send_nack(); /* Master does not send ACK, slave sends it */
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__i2c_send_start();
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if (i2c_put_data( (device << 1) | I2C_READ ) < 0)
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goto device_err;
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__i2c_send_ack(); /* Master sends ACK for continue reading */
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while (cnt)
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{
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if (cnt == 1)
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{
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if (i2c_get_data(buf, 0) < 0)
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break;
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}
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else
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{
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if (i2c_get_data(buf, 1) < 0)
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break;
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}
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cnt--;
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buf++;
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}
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__i2c_send_stop();
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return count - cnt;
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device_err:
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timeout--;
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__i2c_send_stop();
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goto L_try_again;
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L_timeout:
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__i2c_send_stop();
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logf("Read I2C device 0x%2x failed.", device);
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i2c_close();
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return -1;
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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 cnt = count;
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int timeout = 5;
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device &= 0xFF;
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i2c_open();
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__i2c_send_nack(); /* Master does not send ACK, slave sends it */
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W_try_again:
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if (timeout < 0)
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goto W_timeout;
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cnt = count;
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__i2c_send_start();
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if (i2c_put_data( (device << 1) | I2C_WRITE ) < 0)
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goto device_err;
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#if 0 //CONFIG_JZ_TPANEL_ATA2508
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if (address == 0xff)
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{
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while (cnt)
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{
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if (i2c_put_data_nack(*buf) < 0)
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break;
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cnt--;
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buf++;
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}
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}
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else
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#endif
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{
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while (cnt)
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{
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if (i2c_put_data(*buf) < 0)
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break;
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cnt--;
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buf++;
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}
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}
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__i2c_send_stop();
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return count - cnt;
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device_err:
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timeout--;
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__i2c_send_stop();
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goto W_try_again;
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W_timeout:
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logf("Write I2C device 0x%2x failed.", device);
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__i2c_send_stop();
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i2c_close();
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return -1;
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}
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void i2c_init(void)
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{
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}
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