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path: root/drivers/w1/slaves/w1_ds2408.c
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* w1: slaves: w1_ds2408: convert to use w1_family_ops.groupsGreg Kroah-Hartman2013-08-22
| | | | | | | | | | | This moves the sysfs file creation/removal to the w1 core by using the .groups field, saving code in the slave driver. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Jean-Francois Dagenais <jeff.dagenais@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Alexander Stein <alexander.stein@informatik.tu-chemnitz.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* drivers/w1/slaves/w1_ds2408.c: add magic sequence to disable P0 test modeJean-Francois Dagenais2013-07-03
| | | | | | | | | | | | | | | | | | | | | | | | Power-up timing The DS2408 is sensitive to the power-on slew rate and can inadvertently power up with a test mode feature enabled. When this occurs, the P0 port does not respond to the Channel Access Write command. For most reliable operation, it is recommended to disable the test mode after every power-on reset using the Disable Test Mode sequence shown below. The 64-bit ROM code must be transmitted in the same bit sequence as with the Match ROM command, i.e., least significant bit first. This precaution is recommended in parasite power mode (VCC pin connected to GND) as well as with VCC power. Disable Test Mode: RST,PD,96h,<64-bit DS2408 ROM Code>,3Ch,RST,PD [akpm@linux-foundation.org: don't use kerenldoc token to introduce a non-kerneldoc comment, tweak whitespace] Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* w1: add family based automatic module loadingAlexander Stein2013-06-03
| | | | | | | | | This patch allows the 1-wire bus to autoload the corresponding module for each slave being attached. This works similar to bluetooth protocols. Signed-off-by: Alexander Stein <alexander.stein@informatik.tu-chemnitz.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: ds2408: use ARRAY_SIZE instead of hard-coded numberJean-Francois Dagenais2013-03-15
| | | | | | Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: ds2408: make value read-back check a Kconfig optionJean-Francois Dagenais2013-03-15
| | | | | | | | | De-activating this reading back will effectively half the time required for a write to the output register. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* W1: split master mutex to avoid deadlocks.NeilBrown2012-06-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 <neilb@suse.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: w1_ds2408.c: quite sparse noise about using plaing integer as NULL pointerH Hartley Sweeten2012-05-04
| | | | | | | | | 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 <hsweeten@visionengravers.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* w1: fix for loop in w1_f29_remove_slave()Dan Carpenter2011-08-25
| | | | | | | | | | | | | The for loop was looking for i <= 0 instead of i >= 0 so this function never did anything. Also we started with i = NB_SYSFS_BIN_FILES instead of "NB_SYSFS_BIN_FILES - 1" which is an off by one bug. Reported-by: Bojan Prtvar <prtvar.b@gmail.com> Signed-off-by: Dan Carpenter <error27@gmail.com> Acked-by: Jean-Franois Dagenais <dagenaisj@sonatest.com> Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* w1: add 1-wire (w1) DS2408 8-Channel Addressable Switch supportJean-François Dagenais2011-05-26
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. [randy.dunlap@oracle.com: fix w1_ds2408.c printk formats] Signed-off-by: Jean-François Dagenais <dagenaisj@sonatest.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu> Cc: Matt Reimer <mreimer@vpop.net> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>