u-boot/drivers/i2c/ppc4xx_i2c.c

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