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![Dirk Eibach](/assets/img/avatar_default.png)
ppc4xx i2c master gets stuck on errors while repeated start is active. Can be easily reproduced by "i2c md" on an unpopulated i2c address. There is not stop condition given, scl remains pulled low. The only way out seems to be doing a stop manually and then a soft reset. Signed-off-by: Dirk Eibach <dirk.eibach@gdsys.cc> Reviewed-by: Stefan Roese <sr@denx.de>
442 lines
11 KiB
C
442 lines
11 KiB
C
/*
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* (C) Copyright 2007-2009
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* Stefan Roese, DENX Software Engineering, sr@denx.de.
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*
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* based on work by Anne Sophie Harnois <anne-sophie.harnois@nextream.fr>
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*
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* (C) Copyright 2001
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* Bill Hunter, Wave 7 Optics, williamhunter@mediaone.net
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <asm/ppc4xx.h>
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#include <asm/ppc4xx-i2c.h>
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#include <i2c.h>
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#include <asm/io.h>
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DECLARE_GLOBAL_DATA_PTR;
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static inline struct ppc4xx_i2c *ppc4xx_get_i2c(int hwadapnr)
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{
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unsigned long base;
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#if defined(CONFIG_440EP) || defined(CONFIG_440GR) || \
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defined(CONFIG_440EPX) || defined(CONFIG_440GRX) || \
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defined(CONFIG_460EX) || defined(CONFIG_460GT)
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base = CONFIG_SYS_PERIPHERAL_BASE + 0x00000700 + (hwadapnr * 0x100);
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#elif defined(CONFIG_440) || defined(CONFIG_405EX)
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/* all remaining 440 variants */
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base = CONFIG_SYS_PERIPHERAL_BASE + 0x00000400 + (hwadapnr * 0x100);
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#else
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/* all 405 variants */
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base = 0xEF600500 + (hwadapnr * 0x100);
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#endif
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return (struct ppc4xx_i2c *)base;
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}
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static void _i2c_bus_reset(struct i2c_adapter *adap)
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{
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struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
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int i;
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u8 dc;
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/* Reset status register */
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/* write 1 in SCMP and IRQA to clear these fields */
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out_8(&i2c->sts, 0x0A);
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/* write 1 in IRQP IRQD LA ICT XFRA to clear these fields */
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out_8(&i2c->extsts, 0x8F);
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/* Place chip in the reset state */
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out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST);
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/* Check if bus is free */
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dc = in_8(&i2c->directcntl);
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if (!DIRCTNL_FREE(dc)){
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/* Try to set bus free state */
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out_8(&i2c->directcntl, IIC_DIRCNTL_SDAC | IIC_DIRCNTL_SCC);
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/* Wait until we regain bus control */
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for (i = 0; i < 100; ++i) {
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dc = in_8(&i2c->directcntl);
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if (DIRCTNL_FREE(dc))
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break;
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/* Toggle SCL line */
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dc ^= IIC_DIRCNTL_SCC;
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out_8(&i2c->directcntl, dc);
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udelay(10);
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dc ^= IIC_DIRCNTL_SCC;
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out_8(&i2c->directcntl, dc);
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}
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}
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/* Remove reset */
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out_8(&i2c->xtcntlss, 0);
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}
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static void ppc4xx_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr)
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{
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struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
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int val, divisor;
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#ifdef CONFIG_SYS_I2C_INIT_BOARD
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/*
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* Call board specific i2c bus reset routine before accessing the
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* environment, which might be in a chip on that bus. For details
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* about this problem see doc/I2C_Edge_Conditions.
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*/
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i2c_init_board();
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#endif
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/* Handle possible failed I2C state */
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/* FIXME: put this into i2c_init_board()? */
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_i2c_bus_reset(adap);
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/* clear lo master address */
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out_8(&i2c->lmadr, 0);
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/* clear hi master address */
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out_8(&i2c->hmadr, 0);
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/* clear lo slave address */
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out_8(&i2c->lsadr, 0);
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/* clear hi slave address */
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out_8(&i2c->hsadr, 0);
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/* Clock divide Register */
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/* set divisor according to freq_opb */
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divisor = (get_OPB_freq() - 1) / 10000000;
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if (divisor == 0)
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divisor = 1;
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out_8(&i2c->clkdiv, divisor);
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/* no interrupts */
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out_8(&i2c->intrmsk, 0);
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/* clear transfer count */
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out_8(&i2c->xfrcnt, 0);
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/* clear extended control & stat */
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/* write 1 in SRC SRS SWC SWS to clear these fields */
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out_8(&i2c->xtcntlss, 0xF0);
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/* Mode Control Register
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Flush Slave/Master data buffer */
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out_8(&i2c->mdcntl, IIC_MDCNTL_FSDB | IIC_MDCNTL_FMDB);
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val = in_8(&i2c->mdcntl);
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/* Ignore General Call, slave transfers are ignored,
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* disable interrupts, exit unknown bus state, enable hold
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* SCL 100kHz normaly or FastMode for 400kHz and above
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*/
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val |= IIC_MDCNTL_EUBS | IIC_MDCNTL_HSCL;
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if (speed >= 400000)
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val |= IIC_MDCNTL_FSM;
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out_8(&i2c->mdcntl, val);
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/* clear control reg */
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out_8(&i2c->cntl, 0x00);
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}
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/*
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* This code tries to use the features of the 405GP i2c
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* controller. It will transfer up to 4 bytes in one pass
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* on the loop. It only does out_8((u8 *)lbz) to the buffer when it
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* is possible to do out16(lhz) transfers.
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*
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* cmd_type is 0 for write 1 for read.
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*
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* addr_len can take any value from 0-255, it is only limited
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* by the char, we could make it larger if needed. If it is
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* 0 we skip the address write cycle.
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*
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* Typical case is a Write of an addr followd by a Read. The
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* IBM FAQ does not cover this. On the last byte of the write
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* we don't set the creg CHT bit but the RPST bit.
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*
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* It does not support address only transfers, there must be
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* a data part. If you want to write the address yourself, put
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* it in the data pointer.
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*
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* It does not support transfer to/from address 0.
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*
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* It does not check XFRCNT.
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*/
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static int _i2c_transfer(struct i2c_adapter *adap,
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unsigned char cmd_type,
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unsigned char chip,
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unsigned char addr[],
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unsigned char addr_len,
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unsigned char data[],
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unsigned short data_len)
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{
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struct ppc4xx_i2c *i2c = ppc4xx_get_i2c(adap->hwadapnr);
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u8 *ptr;
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int reading;
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int tran, cnt;
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int result;
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int status;
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int i;
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u8 creg;
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if (data == 0 || data_len == 0) {
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/* Don't support data transfer of no length or to address 0 */
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printf( "i2c_transfer: bad call\n" );
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return IIC_NOK;
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}
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if (addr && addr_len) {
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ptr = addr;
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cnt = addr_len;
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reading = 0;
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} else {
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ptr = data;
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cnt = data_len;
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reading = cmd_type;
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}
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/* Clear Stop Complete Bit */
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out_8(&i2c->sts, IIC_STS_SCMP);
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/* Check init */
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i = 10;
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do {
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/* Get status */
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status = in_8(&i2c->sts);
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i--;
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} while ((status & IIC_STS_PT) && (i > 0));
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if (status & IIC_STS_PT) {
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result = IIC_NOK_TOUT;
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return(result);
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}
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/* flush the Master/Slave Databuffers */
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out_8(&i2c->mdcntl, in_8(&i2c->mdcntl) |
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IIC_MDCNTL_FMDB | IIC_MDCNTL_FSDB);
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/* need to wait 4 OPB clocks? code below should take that long */
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/* 7-bit adressing */
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out_8(&i2c->hmadr, 0);
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out_8(&i2c->lmadr, chip);
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tran = 0;
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result = IIC_OK;
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creg = 0;
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while (tran != cnt && (result == IIC_OK)) {
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int bc,j;
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/*
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* Control register =
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* Normal transfer, 7-bits adressing, Transfer up to
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* bc bytes, Normal start, Transfer is a sequence of transfers
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*/
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creg |= IIC_CNTL_PT;
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bc = (cnt - tran) > 4 ? 4 : cnt - tran;
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creg |= (bc - 1) << 4;
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/* if the real cmd type is write continue trans */
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if ((!cmd_type && (ptr == addr)) || ((tran + bc) != cnt))
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creg |= IIC_CNTL_CHT;
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/* last part of address, prepare for repeated start on read */
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if (cmd_type && (ptr == addr) && ((tran + bc) == cnt))
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creg |= IIC_CNTL_RPST;
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if (reading) {
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creg |= IIC_CNTL_READ;
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} else {
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for(j = 0; j < bc; j++) {
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/* Set buffer */
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out_8(&i2c->mdbuf, ptr[tran + j]);
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}
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}
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out_8(&i2c->cntl, creg);
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/*
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* Transfer is in progress
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* we have to wait for upto 5 bytes of data
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* 1 byte chip address+r/w bit then bc bytes
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* of data.
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* udelay(10) is 1 bit time at 100khz
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* Doubled for slop. 20 is too small.
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*/
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i = 2 * 5 * 8;
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do {
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/* Get status */
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status = in_8(&i2c->sts);
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udelay(10);
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i--;
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} while ((status & IIC_STS_PT) && !(status & IIC_STS_ERR) &&
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(i > 0));
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if (status & IIC_STS_ERR) {
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result = IIC_NOK;
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status = in_8(&i2c->extsts);
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/* Lost arbitration? */
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if (status & IIC_EXTSTS_LA)
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result = IIC_NOK_LA;
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/* Incomplete transfer? */
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if (status & IIC_EXTSTS_ICT)
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result = IIC_NOK_ICT;
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/* Transfer aborted? */
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if (status & IIC_EXTSTS_XFRA)
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result = IIC_NOK_XFRA;
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/* Is bus free?
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* If error happened during combined xfer
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* IIC interface is usually stuck in some strange
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* state without a valid stop condition.
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* Brute, but working: generate stop, then soft reset.
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*/
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if ((status & IIC_EXTSTS_BCS_MASK)
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!= IIC_EXTSTS_BCS_FREE){
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u8 mdcntl = in_8(&i2c->mdcntl);
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/* Generate valid stop condition */
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out_8(&i2c->xtcntlss, IIC_XTCNTLSS_SRST);
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out_8(&i2c->directcntl, IIC_DIRCNTL_SCC);
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udelay(10);
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out_8(&i2c->directcntl,
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IIC_DIRCNTL_SCC | IIC_DIRCNTL_SDAC);
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out_8(&i2c->xtcntlss, 0);
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ppc4xx_i2c_init(adap, (mdcntl & IIC_MDCNTL_FSM)
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? 400000 : 100000, 0);
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}
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} else if ( status & IIC_STS_PT) {
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result = IIC_NOK_TOUT;
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}
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/* Command is reading => get buffer */
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if ((reading) && (result == IIC_OK)) {
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/* Are there data in buffer */
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if (status & IIC_STS_MDBS) {
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/*
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* even if we have data we have to wait 4OPB
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* clocks for it to hit the front of the FIFO,
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* after that we can just read. We should check
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* XFCNT here and if the FIFO is full there is
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* no need to wait.
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*/
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udelay(1);
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for (j = 0; j < bc; j++)
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ptr[tran + j] = in_8(&i2c->mdbuf);
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} else
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result = IIC_NOK_DATA;
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}
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creg = 0;
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tran += bc;
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if (ptr == addr && tran == cnt) {
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ptr = data;
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cnt = data_len;
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tran = 0;
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reading = cmd_type;
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}
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}
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return result;
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}
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static int ppc4xx_i2c_probe(struct i2c_adapter *adap, uchar chip)
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{
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uchar buf[1];
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buf[0] = 0;
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/*
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* What is needed is to send the chip address and verify that the
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* address was <ACK>ed (i.e. there was a chip at that address which
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* drove the data line low).
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*/
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return (_i2c_transfer(adap, 1, chip << 1, 0, 0, buf, 1) != 0);
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}
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static int ppc4xx_i2c_transfer(struct i2c_adapter *adap, uchar chip, uint addr,
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int alen, uchar *buffer, int len, int read)
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{
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uchar xaddr[4];
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int ret;
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if (alen > 4) {
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printf("I2C: addr len %d not supported\n", alen);
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return 1;
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}
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if (alen > 0) {
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xaddr[0] = (addr >> 24) & 0xFF;
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xaddr[1] = (addr >> 16) & 0xFF;
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xaddr[2] = (addr >> 8) & 0xFF;
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xaddr[3] = addr & 0xFF;
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}
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#ifdef CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW
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/*
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* EEPROM chips that implement "address overflow" are ones
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* like Catalyst 24WC04/08/16 which has 9/10/11 bits of
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* address and the extra bits end up in the "chip address"
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* bit slots. This makes a 24WC08 (1Kbyte) chip look like
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* four 256 byte chips.
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*
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* Note that we consider the length of the address field to
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* still be one byte because the extra address bits are
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* hidden in the chip address.
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*/
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if (alen > 0)
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chip |= ((addr >> (alen * 8)) &
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CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW);
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#endif
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ret = _i2c_transfer(adap, read, chip << 1, &xaddr[4 - alen], alen,
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buffer, len);
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if (ret) {
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printf("I2C %s: failed %d\n", read ? "read" : "write", ret);
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return 1;
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}
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return 0;
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}
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static int ppc4xx_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr,
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int alen, uchar *buffer, int len)
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{
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return ppc4xx_i2c_transfer(adap, chip, addr, alen, buffer, len, 1);
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}
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static int ppc4xx_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr,
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int alen, uchar *buffer, int len)
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{
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return ppc4xx_i2c_transfer(adap, chip, addr, alen, buffer, len, 0);
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}
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static unsigned int ppc4xx_i2c_set_bus_speed(struct i2c_adapter *adap,
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unsigned int speed)
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{
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if (speed != adap->speed)
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return -1;
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return speed;
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}
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/*
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* Register ppc4xx i2c adapters
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*/
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#ifdef CONFIG_SYS_I2C_PPC4XX_CH0
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U_BOOT_I2C_ADAP_COMPLETE(ppc4xx_0, ppc4xx_i2c_init, ppc4xx_i2c_probe,
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ppc4xx_i2c_read, ppc4xx_i2c_write,
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ppc4xx_i2c_set_bus_speed,
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CONFIG_SYS_I2C_PPC4XX_SPEED_0,
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CONFIG_SYS_I2C_PPC4XX_SLAVE_0, 0)
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#endif
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#ifdef CONFIG_SYS_I2C_PPC4XX_CH1
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U_BOOT_I2C_ADAP_COMPLETE(ppc4xx_1, ppc4xx_i2c_init, ppc4xx_i2c_probe,
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ppc4xx_i2c_read, ppc4xx_i2c_write,
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ppc4xx_i2c_set_bus_speed,
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CONFIG_SYS_I2C_PPC4XX_SPEED_1,
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CONFIG_SYS_I2C_PPC4XX_SLAVE_1, 1)
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#endif
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