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[PATCH] w1: Added w1_reset_select_slave() - Resets the bus and then selects the slave by 

sending either a skip rom or a rom match.

Patch from Ben Gardner <bgardner@wabtec.com>

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Evgeniy Polyakov 2005-08-11 17:27:49 +04:00 committed by Greg Kroah-Hartman
parent db2d0008de
commit ea7d8f65c8
3 changed files with 27 additions and 9 deletions
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24
drivers/w1/w1_io.c
View File

@ -277,6 +277,29 @@ void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb)
w1_search(dev, cb);
}
/**
* Resets the bus and then selects the slave by sending either a skip rom
* or a rom match.
* The w1 master lock must be held.
*
* @param sl the slave to select
* @return 0=success, anything else=error
*/
int w1_reset_select_slave(struct w1_slave *sl)
{
if (w1_reset_bus(sl->master))
return -1;
if (sl->master->slave_count == 1)
w1_write_8(sl->master, W1_SKIP_ROM);
else {
u8 match[9] = {W1_MATCH_ROM, };
memcpy(&match[1], (u8 *)&sl->reg_num, 8);
w1_write_block(sl->master, match, 9);
}
return 0;
}
EXPORT_SYMBOL(w1_touch_bit);
EXPORT_SYMBOL(w1_write_8);
EXPORT_SYMBOL(w1_read_8);
@ -286,3 +309,4 @@ EXPORT_SYMBOL(w1_delay);
EXPORT_SYMBOL(w1_read_block);
EXPORT_SYMBOL(w1_write_block);
EXPORT_SYMBOL(w1_search_devices);
EXPORT_SYMBOL(w1_reset_select_slave);

1
drivers/w1/w1_io.h
View File

@ -34,5 +34,6 @@ u8 w1_calc_crc8(u8 *, int);
void w1_write_block(struct w1_master *, const u8 *, int);
u8 w1_read_block(struct w1_master *, u8 *, int);
void w1_search_devices(struct w1_master *dev, w1_slave_found_callback cb);
int w1_reset_select_slave(struct w1_slave *sl);
#endif /* __W1_IO_H */

11
drivers/w1/w1_therm.c
View File

@ -176,15 +176,10 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
crc = 0;
while (max_trying--) {
if (!w1_reset_bus (dev)) {
if (!w1_reset_select_slave(sl)) {
int count = 0;
u8 match[9] = {W1_MATCH_ROM, };
unsigned int tm = 750;
memcpy(&match[1], (u64 *) & sl->reg_num, 8);
w1_write_block(dev, match, 9);
w1_write_8(dev, W1_CONVERT_TEMP);
while (tm) {
@ -193,8 +188,7 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
flush_signals(current);
}
if (!w1_reset_bus (dev)) {
w1_write_block(dev, match, 9);
if (!w1_reset_select_slave(sl)) {
w1_write_8(dev, W1_READ_SCRATCHPAD);
if ((count = w1_read_block(dev, rom, 9)) != 9) {
@ -205,7 +199,6 @@ static ssize_t w1_therm_read_bin(struct kobject *kobj, char *buf, loff_t off, si
if (rom[8] == crc && rom[0])
verdict = 1;
}
}