aboutsummaryrefslogtreecommitdiff
path: root/drivers/w1/w1_io.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/w1/w1_io.c')
-rw-r--r--drivers/w1/w1_io.c14
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/w1/w1_io.c b/drivers/w1/w1_io.c
index 97b338a16ab..f4f82f1f486 100644
--- a/drivers/w1/w1_io.c
+++ b/drivers/w1/w1_io.c
@@ -293,12 +293,24 @@ int w1_reset_bus(struct w1_master *dev)
result = dev->bus_master->reset_bus(dev->bus_master->data) & 0x1;
else {
dev->bus_master->write_bit(dev->bus_master->data, 0);
+ /* minimum 480, max ? us
+ * be nice and sleep, except 18b20 spec lists 960us maximum,
+ * so until we can sleep with microsecond accuracy, spin.
+ * Feel free to come up with some other way to give up the
+ * cpu for such a short amount of time AND get it back in
+ * the maximum amount of time.
+ */
w1_delay(480);
dev->bus_master->write_bit(dev->bus_master->data, 1);
w1_delay(70);
result = dev->bus_master->read_bit(dev->bus_master->data) & 0x1;
- w1_delay(410);
+ /* minmum 70 (above) + 410 = 480 us
+ * There aren't any timing requirements between a reset and
+ * the following transactions. Sleeping is safe here.
+ */
+ /* w1_delay(410); min required time */
+ msleep(1);
}
return result;