linux-toradex.git/drivers/w1/slaves, branch v3.6.1

1-Wire: Add support for the maxim ds1825 temperature sensor

2012-08-16T19:33:59+00:00

This patch adds support for maxim ds1825 based 1-wire temperature sensors.

Signed-off-by: Raphael Assenat 
Signed-off-by: Greg Kroah-Hartman

w1: Add 1-wire slave device driver for DS28E04-100

2012-06-13T23:47:10+00:00

Signed-off-by: Markus Franke 
Signed-off-by: Greg Kroah-Hartman

W1: split master mutex to avoid deadlocks.

2012-06-13T23:38:40+00:00

The 'mutex' in struct w1_master is use for two very different
purposes.

Firstly it protects various data structures such as the list of all
slaves.

Secondly it protects the w1 buss against concurrent accesses.

This can lead to deadlocks when the ->probe code called while adding a
slave needs to talk on the bus, as is the case for power_supply
devices.
ds2780 and ds2781 drivers contain a work around to track which
process hold the lock simply to avoid this deadlock.  bq27000 doesn't
have that work around and so deadlocks.

There are other possible deadlocks involving sysfs.
When removing a device the sysfs s_active lock is held, so the lock
that protects the slave list must take precedence over s_active.
However when access power_supply attributes via sysfs, the s_active
lock must take precedence over the lock that protects accesses to
the bus.

So to avoid deadlocks between w1 slaves and sysfs, these must be
two separate locks.  Making them separate means that the work around
in ds2780 and ds2781 can be removed.

So this patch:
 - adds a new mutex: "bus_mutex" which serialises access to the bus.
 - takes in mutex in w1_search and ds1wm_search while they access
   the bus for searching.  The mutex is dropped before calling the
   callback which adds the slave.
 - changes all slaves to use bus_mutex instead of mutex to
   protect access to the bus
 - removes w1_ds2790_io_nolock and w1_ds2781_io_nolock, and the
   related code from drivers/power/ds278[01]_battery.c which
   calls them.

Signed-off-by: NeilBrown 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

Revert "w1: introduce a slave mutex for serializing IO"

2012-06-13T23:33:54+00:00

This reverts commit 59d4467be405316916a4087d5b02d99196eeef04.

Turns out it was the wrong version, will apply the correct version after
this.

Reported-by: NeilBrown 
Cc: Evgeniy Polyakov 
Cc: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

w1: introduce a slave mutex for serializing IO

2012-06-12T22:27:32+00:00

w1 devices need a mutex to serial IO.  Most use master->mutex.
However that is used for other purposes and they can conflict.

In particular master->mutex is held while w1_attach_slave_device is
called.

For bq27000, this registers a 'powersupply' device which tries to read the
current status.  The attempt to read will cause a deadlock on
master->mutex.

So create a new per-slave mutex and use that for serializing IO for
bq27000.

Signed-off-by: NeilBrown 
Cc: Evgeniy Polyakov 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

w1: w1_ds2408.c: quite sparse noise about using plaing integer as NULL pointer

2012-05-04T23:25:30+00:00

NULL not 0 should be used with pointers. Just remove the offending
lines since they will default to NULL anyway.

Signed-off-by: H Hartley Sweeten 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

Revert "w1: Add 1-wire slave device driver for DS28E04-100"

2012-04-30T02:12:08+00:00

This reverts commit f19420c1acb0b573c88a12deb2d42035e22d4a17.

It contained lots of errors and warnings and shouldn't have ever been
applied, that was my fault, sorry.

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

w1: w1_ds28e04: unlock on error path in w1_f1C_write_pio()

2012-04-18T22:37:35+00:00

We should unlock here before returning.

Signed-off-by: Dan Carpenter 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman

w1: Add 1-wire slave device driver for DS28E04-100

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

This patch adds a 1-wire slave device driver for the DS28E04-100.

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

DS2781 Maxim Stand-Alone Fuel Gauge battery and w1 slave drivers

2012-03-08T19:15:33+00:00

Signed-off-by: Renata Sayakhova 
Acked-by: Evgeniy Polyakov 
Signed-off-by: Greg Kroah-Hartman