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path: root/drivers/w1/slaves/w1_ds2780.c
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2013-04-30drivers/w1/slaves/w1_ds2780.c: fix the error handling in w1_ds2780_add_slave()Wei Yongjun
Use platform_device_put() instead of platform_device_unregister() if platform_device_add() fail, and platform_device_del() should be used in the error handling case after platform_device_add() success. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Greg KH <greg@kroah.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-06-13W1: split master mutex to avoid deadlocks.NeilBrown
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>
2011-11-02drivers/power/ds2780_battery.c: add a nolock function to w1 interfaceClifton Barnes
Adds a nolock function to the w1 interface to avoid locking the mutex if needed. Signed-off-by: Clifton Barnes <cabarnes@indesign-llc.com> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: <stable@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-11-02w1: ds2760 and ds2780, use ida for id and ida_simple_get() to get itJonathan Cameron
Straightforward. As an aside, the ida_init calls are not needed as far as I can see needed. (DEFINE_IDA does the same already). Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Evgeniy Polyakov <zbr@ioremap.net> Acked-by: Clifton Barnes <cabarnes@indesign-llc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26w1: add Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC supportClifton Barnes
Add support for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC. It was suggested to combine this functionality with the current ds2782 driver. Unfortunately, I'm unable to commit the time to refactoring this driver to that extent and I don't have a platform with the ds2782 part to validate that there are no regression issues by adding this functionality. [akpm@linux-foundation.org: use min_t()] Signed-off-by: Clifton Barnes <cabarnes@indesign-llc.com> Tested-by: Haojian Zhuang <haojian.zhuang@gmail.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Cc: Ryan Mallon <ryan@bluewatersys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>