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/*
* (C) Copyright 2008
* Heiko Schocher, DENX Software Engineering, hs@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
*/
#include <common.h>
#include <mpc8260.h>
#include <ioports.h>
#include <malloc.h>
#if defined(CONFIG_OF_BOARD_SETUP) && defined(CONFIG_OF_LIBFDT)
#include <libfdt.h>
#endif
#if defined(CONFIG_HARD_I2C) || defined(CONFIG_SOFT_I2C)
#include <i2c.h>
#endif
extern int i2c_soft_read_pin (void);
#if defined(CFG_I2C_INIT_BOARD)
#define DELAY_ABORT_SEQ 62
#define DELAY_HALF_PERIOD (500 / (CFG_I2C_SPEED / 1000))
#if defined(CONFIG_MGCOGE)
#define SDA_MASK 0x00010000
#define SCL_MASK 0x00020000
static void set_pin (int state, unsigned long mask)
{
volatile ioport_t *iop = ioport_addr ((immap_t *)CFG_IMMR, 3);
if (state)
iop->pdat |= (mask);
else
iop->pdat &= ~(mask);
iop->pdir |= (mask);
}
static int get_pin (unsigned long mask)
{
volatile ioport_t *iop = ioport_addr ((immap_t *)CFG_IMMR, 3);
iop->pdir &= ~(mask);
return (0 != (iop->pdat & (mask)));
}
static void set_sda (int state)
{
set_pin (state, SDA_MASK);
}
static void set_scl (int state)
{
set_pin (state, SCL_MASK);
}
static int get_sda (void)
{
return get_pin (SDA_MASK);
}
static int get_scl (void)
{
return get_pin (SCL_MASK);
}
#if defined(CONFIG_HARD_I2C)
static void setports (int gpio)
{
volatile ioport_t *iop = ioport_addr ((immap_t *)CFG_IMMR, 3);
if (gpio) {
iop->ppar &= ~(SDA_MASK | SCL_MASK);
iop->podr &= ~(SDA_MASK | SCL_MASK);
} else {
iop->ppar |= (SDA_MASK | SCL_MASK);
iop->pdir &= ~(SDA_MASK | SCL_MASK);
iop->podr |= (SDA_MASK | SCL_MASK);
}
}
#endif
#endif
#if defined(CONFIG_MGSUVD)
static void set_sda (int state)
{
I2C_SDA(state);
}
static void set_scl (int state)
{
I2C_SCL(state);
}
static int get_sda (void)
{
return i2c_soft_read_pin ();
}
static int get_scl (void)
{
int val;
*(unsigned short *)(I2C_BASE_DIR) &= ~SCL_CONF;
udelay (1);
val = *(unsigned char *)(I2C_BASE_PORT);
return ((val & SCL_BIT) == SCL_BIT);
}
#endif
static void writeStartSeq (void)
{
set_sda (1);
udelay (DELAY_HALF_PERIOD);
set_scl (1);
udelay (DELAY_HALF_PERIOD);
set_sda (0);
udelay (DELAY_HALF_PERIOD);
set_scl (0);
udelay (DELAY_HALF_PERIOD);
}
/* I2C is a synchronous protocol and resets of the processor in the middle
of an access can block the I2C Bus until a powerdown of the full unit is
done. This function toggles the SCL until the SCL and SCA line are
released, but max. 16 times, after this a I2C start-sequence is sent.
This I2C Deblocking mechanism was developed by Keymile in association
with Anatech and Atmel in 1998.
*/
static int i2c_make_abort (void)
{
int scl_state = 0;
int sda_state = 0;
int i = 0;
int ret = 0;
if (!get_sda ()) {
ret = -1;
while (i < 16) {
i++;
set_scl (0);
udelay (DELAY_ABORT_SEQ);
set_scl (1);
udelay (DELAY_ABORT_SEQ);
scl_state = get_scl ();
sda_state = get_sda ();
if (scl_state && sda_state) {
ret = 0;
break;
}
}
}
if (ret == 0) {
for (i =0; i < 5; i++) {
writeStartSeq ();
}
}
get_sda ();
return ret;
}
/**
* i2c_init_board - reset i2c bus. When the board is powercycled during a
* bus transfer it might hang; for details see doc/I2C_Edge_Conditions.
*/
void i2c_init_board(void)
{
#if defined(CONFIG_HARD_I2C)
volatile immap_t *immap = (immap_t *)CFG_IMMR ;
volatile i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
/* disable I2C controller first, otherwhise it thinks we want to */
/* talk to the slave port... */
i2c->i2c_i2mod &= ~0x01;
/* Set the PortPins to GPIO */
setports (1);
#endif
/* Now run the AbortSequence() */
i2c_make_abort ();
#if defined(CONFIG_HARD_I2C)
/* Set the PortPins back to use for I2C */
setports (0);
#endif
}
#endif
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