95d58d3058
Explicit if SDA is input or output in static functions Do not use logf() but return codes Check for overflow when adding an interface Indent on 4 spaces Rewrite i2c_read_data() and i2c_write_data() using goto for error cases Make subaddress optional (not sent if == -1) git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19360 a1c6a512-1295-4272-9138-f99709370657
55 lines
2.6 KiB
C
55 lines
2.6 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) 2006 by Linus Nielsen Feltzing
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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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#ifndef _GEN_I2C_
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#define _GEN_I2C_
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struct i2c_interface
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{
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unsigned char address; /* Address of the chip that this interface
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describes */
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void (*scl_hi)(void); /* Drive SCL high, might sleep on clk stretch */
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void (*scl_lo)(void); /* Drive SCL low */
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void (*sda_hi)(void); /* Drive SDA high */
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void (*sda_lo)(void); /* Drive SDA low */
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void (*sda_input)(void); /* Set SDA as input */
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void (*sda_output)(void); /* Set SDA as output */
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void (*scl_input)(void); /* Set SCL as input */
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void (*scl_output)(void); /* Set SCL as output */
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int (*scl)(void); /* Read SCL, returns 0 or non-zero */
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int (*sda)(void); /* Read SDA, returns 0 or non-zero */
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/* These are the delays specified in the I2C specification, the
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time pairs to the right are the minimum 100kHz and 400kHz specs */
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void (*delay_hd_sta)(void); /* START SDA hold (tHD:SDA) 4.0us/0.6us */
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void (*delay_hd_dat)(void); /* SDA hold (tHD:DAT) 5.0us/0us */
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void (*delay_su_dat)(void); /* SDA setup (tSU:DAT) 250ns/100ns */
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void (*delay_su_sto)(void); /* STOP setup (tSU:STO) 4.0us/0.6us */
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void (*delay_su_sta)(void); /* Rep. START setup (tSU:STA) 4.7us/0.6us */
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void (*delay_thigh)(void); /* SCL high period (tHIGH) 4.0us/0.6us */
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};
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extern int i2c_add_node(struct i2c_interface *iface);
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extern int i2c_write_data(int bus_address, int address,
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const unsigned char* buf, int count);
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extern int i2c_read_data(int bus_address, int address,
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unsigned char* buf, int count);
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#endif
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