/*
* 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.
*/
int i2c_make_abort(void)
{
#if defined(CONFIG_HARD_I2C) && !defined(MACH_TYPE_KM_KIRKWOOD)
immap_t *immap = (immap_t *)CONFIG_SYS_IMMR ;
i2c8260_t *i2c = (i2c8260_t *)&immap->im_i2c;
/*
* disable I2C controller first, otherwhise it thinks we want to
* talk to the slave port...
*/
clrbits_8(&i2c->i2c_i2mod, 0x01);
/* Set the PortPins to GPIO */
setports(1);
#endif
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;
printf("[INFO] i2c abort after %d clocks\n", i);
break;
}
}
}
if (ret == 0)
for (i = 0; i < 5; i++)
i2c_write_start_seq();
else
printf("[ERROR] i2c abort failed\n");
/* respect stop setup time */
udelay(DELAY_ABORT_SEQ);
set_scl(1);
udelay(DELAY_ABORT_SEQ);
set_sda(1);
get_sda();
#if defined(CONFIG_HARD_I2C)
/* Set the PortPins back to use for I2C */
setports(0);
#endif
return ret;
}
/*
* 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.
*/
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++)
i2c_write_start_seq();
/* respect stop setup time */
udelay(DELAY_ABORT_SEQ);
set_scl(1);
udelay(DELAY_ABORT_SEQ);
set_sda(1);
get_sda();
return ret;
}
