mirror of
https://github.com/brain-hackers/u-boot-brain
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266 lines
5.0 KiB
C
266 lines
5.0 KiB
C
/*
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* (C) Copyright 2003,Motorola Inc.
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* Xianghua Xiao <x.xiao@motorola.com>
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* Adapted for Motorola 85xx chip.
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*
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* (C) Copyright 2003
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* Gleb Natapov <gnatapov@mrv.com>
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* Some bits are taken from linux driver writen by adrian@humboldt.co.uk
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*
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* Hardware I2C driver for MPC107 PCI bridge.
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*
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* See file CREDITS for list of people who contributed to this
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* project.
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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 as
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* published by the Free Software Foundation; either version 2 of
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* the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
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* MA 02111-1307 USA
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*/
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#include <common.h>
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#include <command.h>
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#include <asm/io.h>
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#ifdef CONFIG_HARD_I2C
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#include <i2c.h>
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#define TIMEOUT (CFG_HZ/4)
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#define I2C_Addr ((u8 *)(CFG_CCSRBAR + 0x3000))
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#define I2CADR &I2C_Addr[0]
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#define I2CFDR &I2C_Addr[4]
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#define I2CCCR &I2C_Addr[8]
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#define I2CCSR &I2C_Addr[12]
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#define I2CCDR &I2C_Addr[16]
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#define I2CDFSRR &I2C_Addr[20]
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#define I2C_READ 1
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#define I2C_WRITE 0
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void
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i2c_init(int speed, int slaveadd)
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{
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/* stop I2C controller */
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writeb(0x0, I2CCCR);
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/* set clock */
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writeb(0x3f, I2CFDR);
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/* set default filter */
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writeb(0x10,I2CDFSRR);
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/* write slave address */
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writeb(slaveadd, I2CADR);
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/* clear status register */
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writeb(0x0, I2CCSR);
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/* start I2C controller */
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writeb(MPC85xx_I2CCR_MEN, I2CCCR);
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}
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static __inline__ int
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i2c_wait4bus (void)
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{
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ulong timeval = get_timer (0);
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while (readb(I2CCSR) & MPC85xx_I2CSR_MBB) {
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if (get_timer (timeval) > TIMEOUT) {
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return -1;
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}
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}
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return 0;
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}
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static __inline__ int
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i2c_wait (int write)
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{
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u32 csr;
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ulong timeval = get_timer (0);
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do {
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csr = readb(I2CCSR);
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if (!(csr & MPC85xx_I2CSR_MIF))
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continue;
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writeb(0x0, I2CCSR);
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if (csr & MPC85xx_I2CSR_MAL) {
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debug("i2c_wait: MAL\n");
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return -1;
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}
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if (!(csr & MPC85xx_I2CSR_MCF)) {
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debug("i2c_wait: unfinished\n");
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return -1;
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}
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if (write == I2C_WRITE && (csr & MPC85xx_I2CSR_RXAK)) {
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debug("i2c_wait: No RXACK\n");
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return -1;
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}
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return 0;
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} while (get_timer (timeval) < TIMEOUT);
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debug("i2c_wait: timed out\n");
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return -1;
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}
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static __inline__ int
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i2c_write_addr (u8 dev, u8 dir, int rsta)
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{
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writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX |
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(rsta?MPC85xx_I2CCR_RSTA:0),
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I2CCCR);
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writeb((dev << 1) | dir, I2CCDR);
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if (i2c_wait (I2C_WRITE) < 0)
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return 0;
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return 1;
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}
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static __inline__ int
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__i2c_write (u8 *data, int length)
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{
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int i;
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writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX,
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I2CCCR);
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for (i=0; i < length; i++) {
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writeb(data[i], I2CCDR);
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if (i2c_wait (I2C_WRITE) < 0)
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break;
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}
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return i;
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}
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static __inline__ int
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__i2c_read (u8 *data, int length)
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{
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int i;
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writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
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((length == 1) ? MPC85xx_I2CCR_TXAK : 0),
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I2CCCR);
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/* dummy read */
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readb(I2CCDR);
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for (i=0; i < length; i++) {
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if (i2c_wait (I2C_READ) < 0)
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break;
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/* Generate ack on last next to last byte */
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if (i == length - 2)
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writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
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MPC85xx_I2CCR_TXAK,
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I2CCCR);
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/* Generate stop on last byte */
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if (i == length - 1)
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writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_TXAK, I2CCCR);
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data[i] = readb(I2CCDR);
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}
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return i;
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}
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int
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i2c_read (u8 dev, uint addr, int alen, u8 *data, int length)
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{
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int i = 0;
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u8 *a = (u8*)&addr;
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if (i2c_wait4bus () < 0)
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goto exit;
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if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
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goto exit;
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if (__i2c_write (&a[4 - alen], alen) != alen)
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goto exit;
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if (i2c_write_addr (dev, I2C_READ, 1) == 0)
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goto exit;
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i = __i2c_read (data, length);
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exit:
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writeb(MPC85xx_I2CCR_MEN, I2CCCR);
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return !(i == length);
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}
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int
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i2c_write (u8 dev, uint addr, int alen, u8 *data, int length)
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{
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int i = 0;
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u8 *a = (u8*)&addr;
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if (i2c_wait4bus () < 0)
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goto exit;
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if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
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goto exit;
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if (__i2c_write (&a[4 - alen], alen) != alen)
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goto exit;
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i = __i2c_write (data, length);
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exit:
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writeb(MPC85xx_I2CCR_MEN, I2CCCR);
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return !(i == length);
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}
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int i2c_probe (uchar chip)
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{
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int tmp;
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/*
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* Try to read the first location of the chip. The underlying
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* driver doesn't appear to support sending just the chip address
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* and looking for an <ACK> back.
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*/
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udelay(10000);
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return i2c_read (chip, 0, 1, (char *)&tmp, 1);
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}
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uchar i2c_reg_read (uchar i2c_addr, uchar reg)
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{
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char buf[1];
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i2c_read (i2c_addr, reg, 1, buf, 1);
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return (buf[0]);
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}
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void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val)
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{
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i2c_write (i2c_addr, reg, 1, &val, 1);
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}
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#endif /* CONFIG_HARD_I2C */
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