linux-toradex.git/drivers/w1/w1_io.c, branch v4.0.9

w1: format for DocBook and fixes

2014-02-07T23:40:18+00:00

Switch the code documentation format style to DocBook format, enable
DocBook documentation generation, and fix some comments.

Signed-off-by: David Fries 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

w1: Disable irqs during 1-wire bus operations, extend 1-wire reset pulse

2012-04-11T23:44:10+00:00

This patch offers the possibility to disables irqs during w1_write_bit()
and w1_reset_bus() operations as timing requirements are very strict for
the 1-wire bus protocol. Per default interrupts are enabled but can be
disabled via the module parameter "w1_disable_irqs".

Extend 1-wire reset pulse length from 480us to 500us as 480us is the
minimum requirement for the 1-wire reset/presence pulse.

Signed-off-by: Markus Franke 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

w1: disable irqs in critical section

2011-11-02T23:07:03+00:00

Interrupting w1_delay() in w1_read_bit() results in missing the low level
on the w1 line and receiving "1" instead of "0".

Add local_irq_save()/local_irq_restore() around the critical section

Signed-off-by: Jan Weitzel 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

MAINTAINERS: Evgeniy has moved

2011-08-25T23:25:33+00:00

Signed-off-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

w1: add 1-wire (w1) reset and resume command API support

2011-05-27T00:12:38+00:00

The first patch adds generic functionnality to w1_io for Resume Command
[A5h] lots of slaves support.  I found it useful for multi-commands/reset
workflows with the same slave on a multi-slave bus.

This DS2408 w1 slave driver is not complete for all the features of the
chip, but its sufficient if you use it as a simple IO expander.  Enjoy!

The ds1wm had Kconfig dependencies towards ARM && HAVE_CLK.  I took them
out since I was using the ds1wm on an x86_64 platform (ds1wm in a FPGA
through pcie) and found them irrelevant.

The clock freq/divisors at the top of ds1wm.c did not have the MSB set to
1.  This bit is CLK_EN which turns the whole prescaler and dividers on.
The driver never mentionned this bit either, so I just included this bit
right in the table entries.  I also took the liberty to add a couple of
entries to the table.  The spec doesn't explicitely mentions these
possibilities but the description and examination of the core shows the
prescalers & dividers can be used for more than the table explicitely
shows.  The table I enlarged still doesn't cover all possibilities, but
it's a good start.

I also made a few tweaks to a couple of the read and write algorithms
which made sense while I had my head very deep in the ds1wm documentation.
 We stressed it a lot with 10+ slaves on the bus, many ds2408, ds2431 and
ds2433 at the same time doing extensive interaction.  It proved quite
stable in our production environment.

This patch:

Add generic functionnality to w1_io for Resume Command [A5h] lots of
slaves support.

Signed-off-by: Jean-François Dagenais 
Cc: Evgeniy Polyakov 
Cc: Szabolcs Gyurko 
Cc: Matt Reimer 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

w1: coding style cleanups in w1_io.c

2009-04-03T02:05:04+00:00

This fixes a number of coding style issues I stubled over.

Acked-by: Evgeniy Polyakov 
Signed-off-by: Daniel Mack 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

w1: add touch block command

2009-01-08T16:31:13+00:00

Writes and returns sampled data back to userspace.

Signed-off-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

w1: fix slave selection on big-endian systems

2008-12-23T23:58:21+00:00

During test of the w1-gpio driver i found that in "w1.c:679
w1_slave_found()" the device id is converted to little-endian with
"cpu_to_le64()", but its not converted back to cpu format in "w1_io.c:293
w1_reset_select_slave()".

Based on a patch created by Andreas Hummel.

[akpm@linux-foundation.org: remove unneeded cast]
Reported-by: Andreas Hummel 
Signed-off-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

w1: export w1_read_8 function

2008-11-13T01:17:18+00:00

Export the w1_read_8 function for use of drivers.  The OMAP HDQ
driver(drivers/w1/masters/omap_hdq.c) uses this function.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Madhusudhan Chikkature
Acked-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

W1: w1_io.c reset comments and msleep

2008-10-16T18:21:50+00:00

w1_reset_bus, added some comments about the timing and switched to msleep
for the later delay.  I don't have the hardware to test the sleep after
reset change.  The one wire doesn't have a timing requirement between
commands so it is fine.  I do have the USB hardware and it would be in big
trouble with 10ms interrupt transfers to find that the reset completed.

Signed-off-by: David Fries 
Signed-off-by: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds