linux/drivers/w1/masters
Mariusz Bialonczyk f704938c0e w1: enable active pullup for DS2482 by default
This commit enables the active pullup (APU bit) by default for
the DS2482 1-Wire master.

>From the DS2482 datasheet:
"The APU bit controls whether an active pullup (controlled slew-rate
transistor) or a passive pullup (Rwpu resistor) will be used to drive
a 1-Wire line from low to high. When APU = 0, active pullup is disabled
(resistor mode). Active Pullup should always be selected unless there is
only a single slave on the 1-Wire line."

According to the module author, Ben Gardner:
"It doesn't look like active pullup would cause any hurt if there
is only a single slave."
And my tests with multiple and single slaves on 1-Wire bus
confirms that.

This active pullup can be manually disabled using the introduced
module parameter:
  active_pullup = 0

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01 14:04:19 -07:00
..
Kconfig w1: mxc_w1: Enable driver compilation with COMPILE_TEST 2014-02-28 15:27:09 -08:00
Makefile w1: add 1-wire master driver for i.MX27 / i.MX31 2009-01-08 08:31:13 -08:00
ds1wm.c w1/masters: use pr_* instead of printk 2014-06-19 17:46:51 -07:00
ds2482.c w1: enable active pullup for DS2482 by default 2016-05-01 14:04:19 -07:00
ds2490.c W1: ds2490: Increase timeout when waiting for status 2014-11-07 11:24:01 -08:00
matrox_w1.c Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-09-01 18:46:42 -07:00
mxc_w1.c w1: constify of_device_id array 2015-03-25 12:25:29 +01:00
omap_hdq.c omap_hdq: fix usecount handling 2016-02-08 14:57:30 -08:00
w1-gpio.c W1: w1-gpio - switch to using dev_pm_ops 2015-10-17 21:45:05 -07:00