mirror of
https://xff.cz/git/u-boot/
synced 2025-09-01 16:52:14 +02:00
soft_i2c: move to drivers/i2c
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
This commit is contained in:
Jean-Christophe PLAGNIOL-VILLARD
423
drivers/i2c/soft_i2c.c
Normal file
423
drivers/i2c/soft_i2c.c
Normal file
@@ -0,0 +1,423 @@
|
||||
/*
|
||||
* (C) Copyright 2001, 2002
|
||||
* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
|
||||
*
|
||||
* See file CREDITS for list of people who contributed to this
|
||||
* project.
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or
|
||||
* modify it under the terms of the GNU General Public License as
|
||||
* published by the Free Software Foundation; either version 2 of
|
||||
* the License, or (at your option) any later version.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, write to the Free Software
|
||||
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
|
||||
* MA 02111-1307 USA
|
||||
*
|
||||
* This has been changed substantially by Gerald Van Baren, Custom IDEAS,
|
||||
* vanbaren@cideas.com. It was heavily influenced by LiMon, written by
|
||||
* Neil Russell.
|
||||
*/
|
||||
|
||||
#include <common.h>
|
||||
#ifdef CONFIG_MPC8260 /* only valid for MPC8260 */
|
||||
#include <ioports.h>
|
||||
#endif
|
||||
#ifdef CONFIG_AT91RM9200 /* need this for the at91rm9200 */
|
||||
#include <asm/io.h>
|
||||
#include <asm/arch/hardware.h>
|
||||
#endif
|
||||
#ifdef CONFIG_IXP425 /* only valid for IXP425 */
|
||||
#include <asm/arch/ixp425.h>
|
||||
#endif
|
||||
#ifdef CONFIG_LPC2292
|
||||
#include <asm/arch/hardware.h>
|
||||
#endif
|
||||
#include <i2c.h>
|
||||
|
||||
/* #define DEBUG_I2C */
|
||||
|
||||
#ifdef DEBUG_I2C
|
||||
DECLARE_GLOBAL_DATA_PTR;
|
||||
#endif
|
||||
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Definitions
|
||||
*/
|
||||
|
||||
#define RETRIES 0
|
||||
|
||||
|
||||
#define I2C_ACK 0 /* PD_SDA level to ack a byte */
|
||||
#define I2C_NOACK 1 /* PD_SDA level to noack a byte */
|
||||
|
||||
|
||||
#ifdef DEBUG_I2C
|
||||
#define PRINTD(fmt,args...) do { \
|
||||
if (gd->have_console) \
|
||||
printf (fmt ,##args); \
|
||||
} while (0)
|
||||
#else
|
||||
#define PRINTD(fmt,args...)
|
||||
#endif
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Local functions
|
||||
*/
|
||||
static void send_reset (void);
|
||||
static void send_start (void);
|
||||
static void send_stop (void);
|
||||
static void send_ack (int);
|
||||
static int write_byte (uchar byte);
|
||||
static uchar read_byte (int);
|
||||
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Send a reset sequence consisting of 9 clocks with the data signal high
|
||||
* to clock any confused device back into an idle state. Also send a
|
||||
* <stop> at the end of the sequence for belts & suspenders.
|
||||
*/
|
||||
static void send_reset(void)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
int j;
|
||||
|
||||
I2C_SCL(1);
|
||||
I2C_SDA(1);
|
||||
#ifdef I2C_INIT
|
||||
I2C_INIT;
|
||||
#endif
|
||||
I2C_TRISTATE;
|
||||
for(j = 0; j < 9; j++) {
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_DELAY;
|
||||
}
|
||||
send_stop();
|
||||
I2C_TRISTATE;
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* START: High -> Low on SDA while SCL is High
|
||||
*/
|
||||
static void send_start(void)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
|
||||
I2C_DELAY;
|
||||
I2C_SDA(1);
|
||||
I2C_ACTIVE;
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_SDA(0);
|
||||
I2C_DELAY;
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* STOP: Low -> High on SDA while SCL is High
|
||||
*/
|
||||
static void send_stop(void)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_SDA(0);
|
||||
I2C_ACTIVE;
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_SDA(1);
|
||||
I2C_DELAY;
|
||||
I2C_TRISTATE;
|
||||
}
|
||||
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* ack should be I2C_ACK or I2C_NOACK
|
||||
*/
|
||||
static void send_ack(int ack)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_ACTIVE;
|
||||
I2C_SDA(ack);
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_DELAY;
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
}
|
||||
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Send 8 bits and look for an acknowledgement.
|
||||
*/
|
||||
static int write_byte(uchar data)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
int j;
|
||||
int nack;
|
||||
|
||||
I2C_ACTIVE;
|
||||
for(j = 0; j < 8; j++) {
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_SDA(data & 0x80);
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_DELAY;
|
||||
|
||||
data <<= 1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Look for an <ACK>(negative logic) and return it.
|
||||
*/
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_SDA(1);
|
||||
I2C_TRISTATE;
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
I2C_DELAY;
|
||||
nack = I2C_READ;
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_ACTIVE;
|
||||
|
||||
return(nack); /* not a nack is an ack */
|
||||
}
|
||||
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* if ack == I2C_ACK, ACK the byte so can continue reading, else
|
||||
* send I2C_NOACK to end the read.
|
||||
*/
|
||||
static uchar read_byte(int ack)
|
||||
{
|
||||
#ifdef CONFIG_MPC8260
|
||||
volatile ioport_t *iop = ioport_addr((immap_t *)CFG_IMMR, I2C_PORT);
|
||||
#endif
|
||||
#ifdef CONFIG_8xx
|
||||
volatile immap_t *immr = (immap_t *)CFG_IMMR;
|
||||
#endif
|
||||
int data;
|
||||
int j;
|
||||
|
||||
/*
|
||||
* Read 8 bits, MSB first.
|
||||
*/
|
||||
I2C_TRISTATE;
|
||||
I2C_SDA(1);
|
||||
data = 0;
|
||||
for(j = 0; j < 8; j++) {
|
||||
I2C_SCL(0);
|
||||
I2C_DELAY;
|
||||
I2C_SCL(1);
|
||||
I2C_DELAY;
|
||||
data <<= 1;
|
||||
data |= I2C_READ;
|
||||
I2C_DELAY;
|
||||
}
|
||||
send_ack(ack);
|
||||
|
||||
return(data);
|
||||
}
|
||||
|
||||
/*=====================================================================*/
|
||||
/* Public Functions */
|
||||
/*=====================================================================*/
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Initialization
|
||||
*/
|
||||
void i2c_init (int speed, int slaveaddr)
|
||||
{
|
||||
/*
|
||||
* WARNING: Do NOT save speed in a static variable: if the
|
||||
* I2C routines are called before RAM is initialized (to read
|
||||
* the DIMM SPD, for instance), RAM won't be usable and your
|
||||
* system will crash.
|
||||
*/
|
||||
send_reset ();
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Probe to see if a chip is present. Also good for checking for the
|
||||
* completion of EEPROM writes since the chip stops responding until
|
||||
* the write completes (typically 10mSec).
|
||||
*/
|
||||
int i2c_probe(uchar addr)
|
||||
{
|
||||
int rc;
|
||||
|
||||
/*
|
||||
* perform 1 byte write transaction with just address byte
|
||||
* (fake write)
|
||||
*/
|
||||
send_start();
|
||||
rc = write_byte ((addr << 1) | 0);
|
||||
send_stop();
|
||||
|
||||
return (rc ? 1 : 0);
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Read bytes
|
||||
*/
|
||||
int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
|
||||
{
|
||||
int shift;
|
||||
PRINTD("i2c_read: chip %02X addr %02X alen %d buffer %p len %d\n",
|
||||
chip, addr, alen, buffer, len);
|
||||
|
||||
#ifdef CFG_I2C_EEPROM_ADDR_OVERFLOW
|
||||
/*
|
||||
* 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.
|
||||
*
|
||||
* 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.
|
||||
*/
|
||||
chip |= ((addr >> (alen * 8)) & CFG_I2C_EEPROM_ADDR_OVERFLOW);
|
||||
|
||||
PRINTD("i2c_read: fix addr_overflow: chip %02X addr %02X\n",
|
||||
chip, addr);
|
||||
#endif
|
||||
|
||||
/*
|
||||
* Do the addressing portion of a write cycle to set the
|
||||
* chip's address pointer. If the address length is zero,
|
||||
* don't do the normal write cycle to set the address pointer,
|
||||
* there is no address pointer in this chip.
|
||||
*/
|
||||
send_start();
|
||||
if(alen > 0) {
|
||||
if(write_byte(chip << 1)) { /* write cycle */
|
||||
send_stop();
|
||||
PRINTD("i2c_read, no chip responded %02X\n", chip);
|
||||
return(1);
|
||||
}
|
||||
shift = (alen-1) * 8;
|
||||
while(alen-- > 0) {
|
||||
if(write_byte(addr >> shift)) {
|
||||
PRINTD("i2c_read, address not <ACK>ed\n");
|
||||
return(1);
|
||||
}
|
||||
shift -= 8;
|
||||
}
|
||||
send_stop(); /* reportedly some chips need a full stop */
|
||||
send_start();
|
||||
}
|
||||
/*
|
||||
* Send the chip address again, this time for a read cycle.
|
||||
* Then read the data. On the last byte, we do a NACK instead
|
||||
* of an ACK(len == 0) to terminate the read.
|
||||
*/
|
||||
write_byte((chip << 1) | 1); /* read cycle */
|
||||
while(len-- > 0) {
|
||||
*buffer++ = read_byte(len == 0);
|
||||
}
|
||||
send_stop();
|
||||
return(0);
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Write bytes
|
||||
*/
|
||||
int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
|
||||
{
|
||||
int shift, failures = 0;
|
||||
|
||||
PRINTD("i2c_write: chip %02X addr %02X alen %d buffer %p len %d\n",
|
||||
chip, addr, alen, buffer, len);
|
||||
|
||||
send_start();
|
||||
if(write_byte(chip << 1)) { /* write cycle */
|
||||
send_stop();
|
||||
PRINTD("i2c_write, no chip responded %02X\n", chip);
|
||||
return(1);
|
||||
}
|
||||
shift = (alen-1) * 8;
|
||||
while(alen-- > 0) {
|
||||
if(write_byte(addr >> shift)) {
|
||||
PRINTD("i2c_write, address not <ACK>ed\n");
|
||||
return(1);
|
||||
}
|
||||
shift -= 8;
|
||||
}
|
||||
|
||||
while(len-- > 0) {
|
||||
if(write_byte(*buffer++)) {
|
||||
failures++;
|
||||
}
|
||||
}
|
||||
send_stop();
|
||||
return(failures);
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Read a register
|
||||
*/
|
||||
uchar i2c_reg_read(uchar i2c_addr, uchar reg)
|
||||
{
|
||||
uchar buf;
|
||||
|
||||
i2c_read(i2c_addr, reg, 1, &buf, 1);
|
||||
|
||||
return(buf);
|
||||
}
|
||||
|
||||
/*-----------------------------------------------------------------------
|
||||
* Write a register
|
||||
*/
|
||||
void i2c_reg_write(uchar i2c_addr, uchar reg, uchar val)
|
||||
{
|
||||
i2c_write(i2c_addr, reg, 1, &val, 1);
|
||||
}
|
||||
Reference in New Issue
Block a user