/**
* w1_triplet() - * Does a triplet - used for searching ROM addresses.
* @dev: the master device
* @bdir: the bit to write if both id_bit and comp_bit are 0
*
* Return bits:
* bit 0 = id_bit
* bit 1 = comp_bit
* bit 2 = dir_taken
* If both bits 0 & 1 are set, the search should be restarted.
*
* Return: bit fields - see above
*/
u8 w1_triplet(struct w1_master *dev, int bdir)
{
if (dev->bus_master->triplet)
return dev->bus_master->triplet(dev->bus_master->data, bdir);
else {
u8 id_bit = w1_touch_bit(dev, 1);
u8 comp_bit = w1_touch_bit(dev, 1);
u8 retval;
if (id_bit && comp_bit)
return 0x03; /* error */
if (!id_bit && !comp_bit) {
/* Both bits are valid, take the direction given */
retval = bdir ? 0x04 : 0;
} else {
/* Only one bit is valid, take that direction */
bdir = id_bit;
retval = id_bit ? 0x05 : 0x02;
}
if (dev->bus_master->touch_bit)
w1_touch_bit(dev, bdir);
else
w1_write_bit(dev, bdir);
return retval;
}
}
u8 w1_triplet(struct w1_master *dev, int bdir)
{
if (dev->bus_master->triplet)
return dev->bus_master->triplet(dev->bus_master->data, bdir);
else {
u8 id_bit = w1_touch_bit(dev, 1);
u8 comp_bit = w1_touch_bit(dev, 1);
u8 retval;
if (id_bit && comp_bit)
return 0x03; /* */
if (!id_bit && !comp_bit) {
/* */
retval = bdir ? 0x04 : 0;
} else {
/* */
bdir = id_bit;
retval = id_bit ? 0x05 : 0x02;
}
if (dev->bus_master->touch_bit)
w1_touch_bit(dev, bdir);
else
w1_write_bit(dev, bdir);
return retval;
}
}
/**
* w1_touch_bit() - Generates a write-0 or write-1 cycle and samples the level.
* @dev: the master device
* @bit: 0 - write a 0, 1 - write a 0 read the level
*/
static u8 w1_touch_bit(struct w1_master *dev, int bit)
{
if (dev->bus_master->touch_bit)
return dev->bus_master->touch_bit(dev->bus_master->data, bit);
else if (bit)
return w1_read_bit(dev);
else {
w1_write_bit(dev, 0);
return 0;
}
}