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path: root/drivers/w1/w1.c
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2017-04-08w1: Remove unneeded use of assert() and remove w1_log.hAndrew F. Davis
The only use of assert() is in matrox_w1.c and is used to check the input to probe() from the PCI subsystem for NULL values, these are guaranteed to be populated and no other PCI driver makes this check, remove this. As this was the only definition in w1_log.h, remove this also. Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25w1: Fixup source file headersAndrew F. Davis
Remove filename from file, this is not done anymore as it doesn't add anything and usually is incorrect as filename change often. Also shorten the GPL to the more common address-less version and remove excess white-space. Signed-off-by: Andrew F. Davis <afd@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25w1: don't leak refcount on slave attach failure in w1_attach_slave_device()Maciej S. Szmigiero
Near the beginning of w1_attach_slave_device() we increment a w1 master reference count. Later, when we are going to exit this function without actually attaching a slave device (due to failure of __w1_attach_slave_device()) we need to decrement this reference count back. Signed-off-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name> Cc: stable@vger.kernel.org Fixes: 9fcbbac5ded489 ("w1: process w1 netlink commands in w1_process thread") Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31w1: fix timeout_us parameter descriptionWei Yongjun
Fix 'timeout_us' parameter description. Signed-off-by: Wei Yongjun <weiyj.lk@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-01w1: silence an uninitialized variable warningDan Carpenter
If kstrtoint() returns -ERANGE then "tmp" is uninitialized. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Evgeniy Polaykov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-11w1: w1_process() is not freezable kthreadJiri Kosina
w1_process() calls try_to_freeze(), but the thread doesn't mark itself freezable through set_freezable(), so the try_to_freeze() call is useless. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-24w1: introduce an ability to specify microseconds bus scanning intervalsDmitry Khromov
Some of 1-Wire devices commonly associated with physical access control systems are attached/generate presence for as short as 100 ms - hence the tens-to-hundreds milliseconds scan intervals are required. Signed-off-by: Dmitry Khromov <dk@icelogic.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-26w1: support auto-load of w1_bq27000 module.NeilBrown
1/ change request_module call to zero-pad single digit family numbers. This appears to be the intention of the code, but not what it actually does. This means that the alias created for W1_FAMILY_SMEM_01 might actually be useful. 2/ Define a family name for the BQ27000 battery charge monitor. Unfortunately this is the same number as W1_FAMILY_SMEM_01 so if both a compiled on a system, one module might need to be blacklisted. 3/ Add a MODULE_ALIAS for the bq27000. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-19w1: use pr_* instead of printkFjodor Schelichow
This patch replaces all calls to the "printk" function within the main "w1" directory by calls to the appropriate "pr_*" function thus addressing the following warning generated by the checkpatch script: WARNING: Prefer [subsystem eg: netdev]_err([subsystem]dev, ... then dev_err(dev, ... then pr_err(... to printk(KERN_ERR ... Signed-off-by: Fjodor Schelichow <fjodor.schelichow@hotmail.com> Signed-off-by: Roman Sommer <romsom2@yahoo.de> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-05-27w1: do not unlock unheld list_mutex in __w1_remove_master_device()Alexey Khoroshilov
w1_process_callbacks() expects to be called with dev->list_mutex held, but it is the fact only in w1_process(). __w1_remove_master_device() calls w1_process_callbacks() after it releases list_mutex. The patch fixes __w1_remove_master_device() to acquire list_mutex for w1_process_callbacks(). Found by Linux Driver Verification project (linuxtesting.org). Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru> Acked-by: David Fries <david@fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@vger.kernel.org> # 3.15 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-16w1: avoid recursive device_addDavid Fries
__w1_attach_slave_device calls device_add which calls w1_bus_notify which calls the w1_bq27000 slave driver, which calls platform_device_add and device_add and deadlocks on getting &(&priv->bus_notifier)->rwsem as it is still held in the previous device_add. This avoids the problem by processing the family add/remove outside of the slave device_add call. Commit 47eba33a0997fc7362a introduced this deadlock and added a KOBJ_ADD, as the add was already reported in device_register two add events were being sent. This change suppresses the device_register add so that any slave device sysfs entries are setup before the add goes out. Belisko Marek reported this change fixed the deadlock he was seeing on ARM device tree, while testing on my x86-64 system never saw the deadlock. Reported-by: Belisko Marek <marek.belisko@gmail.com> Signed-off-by: David Fries <David@Fries.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-15w1: small type cleanup in sysfsDan Carpenter
On 64 bit systems, a large value for "long tmp" is truncated when assigning to "int md->max_slave_count" so we still end up with a value less than one despite the "tmp < 1" check. This is more of a problem for static checkers than a real life issue, but it's simple enough to fix. Acked-by: David Fries <david@fries.net> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: format for DocBook and fixesDavid Fries
Switch the code documentation format style to DocBook format, enable DocBook documentation generation, and fix some comments. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: process w1 netlink commands in w1_process threadDavid Fries
Netlink is a socket interface and is expected to be asynchronous. Clients can now make w1 requests without blocking by making use of the w1_master thread to process netlink commands which was previously only used for doing an automatic bus search. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: new netlink commands, add/remove/list slavesDavid Fries
Introduce new commands to add, remove, and list slave devices through the netlink interface. This can be useful to skip the search on a static network. They could previously only be added or removed through automatic search or sysfs, and this allows a program to only use netlink. Only allocate memory when needed, so move kzalloc into w1_get_slaves where it was used. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: continue slave search where previous left offDavid Fries
Search will detect at most max_slave_count devices per run, if there are more pick up the next search where the previous left off. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: increase w1_max_slave_count, allow write accessDavid Fries
w1_max_slave_count is only used to abort the search early or take a fast search (when 1), so there isn't any reason to not allow it to be updated through sysfs. Memory is not allocated based on the current value and 10 is a rather low base number, increasing to 64, and printing a message the first time the count is reached and there were more devices to discover to let the user know why not all the devices were found. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: Only wake up the search process if it is going to be searchingDavid Fries
It's valid to set the search count to 0 to stop searching, so don't wake up the search thread to not search. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07w1: fixup search to support abort from netlinkDavid Fries
Before 63706172f33 "rework kthread_stop()" kthread_should_stop() always returned false when called from a non-kthread task, after it would oops as a non-kthread didn't have that structure and netlink was calling search from a thread which wasn't a kthread. 9d1817cab2f030 "w1: fix oops when w1_search is called from netlink connector", modified the code to avoid calling kthread_stop from a netlink thread. Introduce a w1_master flag and bit W1_ABORT_SEARCH to identify abort to cleanly support both kthread and netlink search abort. A search can take seconds to run, so it is important to abort early if the hardware is removed in the middle of a search. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Marcin Jurkowski <marcin1j@gmail.com> Cc: Josh Boyer <jwboyer@gmail.com> Cc: Sven Geggus <lists@fuchsschwanzdomain.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-13drivers: w1: make w1_slave::flags long to avoid memory corruptionMichal Nazarewicz
On architectures where long is more then 32 bits, modifying a 32-bit field with set_bit (and other atomic bit operations) may cause bytes following the field to by modified. Because the endianness of the bits within a field is the native endianness of the CPU[1], on big-endian machines, bit number zero is in the last byte of the field. Therefore, `set_bit(0, ptr)' on a 64-bit big-endian machine is roughly equivalent to `((char *)ptr)[7] |= 1', and since w1 driver uses a 32-bit field for holding the flags, this causes bytes beyond the field to be modified. [1] From Documentation/atomic_ops.txt: Native atomic bit operations are defined to operate on objects aligned to the size of an "unsigned long" C data type, and are least of that size. The endianness of the bits within each "unsigned long" are the native endianness of the cpu. Signed-off-by: Michal Nazarewicz <mina86@mina86.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>
2013-10-07w1 - call request_module with w1 master mutex unlockedHans-Frieder Vogt
request_module for w1 slave modules needs to be called with the w1 master mutex unlocked. Because w1_attach_slave_device gets always(?) called with mutex locked, we need to temporarily unlock the w1 master mutex for the loading of the w1 slave module. Signed-off by: Hans-Frieder Vogt <hfvogt@gmx.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@vger.kernel.org> # 3.11+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-10-07w1 - fix fops in w1_bus_notifyHans-Frieder Vogt
Introduce a check to make sure that fops are only called if they have been defined by the slave module. Without this check modules like w1_smem cause a NULL pointer dereference bug. Signed-off by: Hans-Frieder Vogt <hfvogt@gmx.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@vger.kernel.org> # 3.11+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-11drivers/w1/w1.c: replace strict_strtol() with kstrtol()Jingoo Han
The usage of strict_strtol() is not preferred, because strict_strtol() is obsolete. Thus, kstrtol() should be used. Signed-off-by: Jingoo Han <jg1.han@samsung.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>
2013-08-22w1: add attribute groups to struct w1_family_opsGreg Kroah-Hartman
This lets w1 slave drivers declare an attribute group, and not have to create/destroy sysfs files directly. All w1 slave drivers will be fixed to use this field up in follow-on patches to this one. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22w1: use default attribute groups for w1 slave devicesGreg Kroah-Hartman
As we have 2 sysfs files for the w1 slave devices, let the driver core create / destroy them automatically by setting the default attribute group for them, saving code and housekeeping logic. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22w1: remove race with sysfs file creationGreg Kroah-Hartman
W1 slave sysfs files are created _after_ userspace is notified that the device has been added to the system. Fix that race by moving the creation/remove of the files to the bus notifier that is there for doing this type of thing. Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-06-03w1: add family based automatic module loadingAlexander Stein
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>
2013-03-12w1: fix oops when w1_search is called from netlink connectorMarcin Jurkowski
On Sat, Mar 02, 2013 at 10:45:10AM +0100, Sven Geggus wrote: > This is the bad commit I found doing git bisect: > 04f482faf50535229a5a5c8d629cf963899f857c is the first bad commit > commit 04f482faf50535229a5a5c8d629cf963899f857c > Author: Patrick McHardy <kaber@trash.net> > Date: Mon Mar 28 08:39:36 2011 +0000 Good job. I was too lazy to bisect for bad commit;) Reading the code I found problematic kthread_should_stop call from netlink connector which causes the oops. After applying a patch, I've been testing owfs+w1 setup for nearly two days and it seems to work very reliable (no hangs, no memleaks etc). More detailed description and possible fix is given below: Function w1_search can be called from either kthread or netlink callback. While the former works fine, the latter causes oops due to kthread_should_stop invocation. This patch adds a check if w1_search is serving netlink command, skipping kthread_should_stop invocation if so. Signed-off-by: Marcin Jurkowski <marcin1j@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Josh Boyer <jwboyer@gmail.com> Tested-by: Sven Geggus <lists@fuchsschwanzdomain.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: stable <stable@vger.kernel.org> # 3.0+
2012-11-21w1: remove CONFIG_HOTPLUG ifdefsBill Pemberton
Remove conditional code based on CONFIG_HOTPLUG being false. It's always on now in preparation of it going away as an option. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>
2012-06-13Revert "w1: introduce a slave mutex for serializing IO"Greg Kroah-Hartman
This reverts commit 59d4467be405316916a4087d5b02d99196eeef04. Turns out it was the wrong version, will apply the correct version after this. Reported-by: NeilBrown <neilb@suse.de> Cc: Evgeniy Polyakov <zbr@ioremap.net> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-12w1: cleanup w1_ueventDevendra Naga
There were some return statements around in the w1_uevent, used goto to cleanup those return statements with the help of err variable, and also removed a semi colon at the end of the w1_uevent's closing brace. Signed-off-by: Devendra Naga <devendra.aaru@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-06-12w1: introduce a slave mutex for serializing IONeilBrown
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 <neilb@suse.de> Cc: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-09w1: fix slave driver registration error messageDmitry Artamonow
W1 core prints "Failed to register master driver" if error happens on registering SLAVE driver. Fix it. Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-12-09w1: add fast search for single slave busEvgeniy Polyakov
This enables a much more efficient way of device searching. It uses the 1-wire read-rom operation which allows the direct reading of the slave address. BUT this works only with exactly one slave on the bus. Signed-off-by: Hubert Feurstein <h.feurstein@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> index c374978..9761950 100644 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-08-25MAINTAINERS: Evgeniy has movedEvgeniy Polyakov
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26w1: have netlink search update kernel listDavid Fries
Reorganize so the netlink connector one wire search command will update the kernel list of detected slave devices. Otherwise, a newly detected device is unusable because unless it's in the kernel list of known devices any commands will result in ENODEV status. Signed-off-by: David Fries <David@Fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27w1: don't allow arbitrary users to remove w1 devicesBrian Swetland
The search/pullup/add/remove device attributes were 0666 which would allow arbitrary users to affect the 1 wire bus. Change to 0664 to prevent that. I found this patch in the Android tree, apparently this has never been sent upstream so doing it now. Signed-off-by: Brian Swetland <swetland@google.com> Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright
This allows bin_attr->read,write,mmap callbacks to check file specific data (such as inode owner) as part of any privilege validation. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-05w1: add __init/__exit macros to w1.cPeter Huewe
Trivial patch which adds the __init/__exit macros to the module_init/ module_exit functions of drivers/w1/w1.c Signed-off-by: Peter Huewe <peterhuewe@gmx.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-01-06w1: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers
CC: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-10-16W1: w1.c s/printk/dev_dbg/David Fries
s/printk/dev_dbg/ Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: w1_slave_read_id read bug, use device_attributeDavid Fries
Fix bug reading the id sysfs file. If less than the full 8 bytes were read, the next read would start at the first byte instead of continuing. It needed the offset added to memcpy, or the better solution was to replace it with the device attribute instead of bin attribute. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: recode w1_slave_found logicDavid Fries
Simplified the logic in w1_slave_found by using the new w1_attach_slave_device function to find a slave and mark it as active or add the device if the crc checks. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: be able to manually add and remove slavesDavid Fries
sysfs entries were added to manually add and remove slave devices. This is useful if the automatic bus searching is disabled, and the device ids are already known. [akpm@linux-foundation.org: fix printk types] Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: feature, enable hardware strong pullupDavid Fries
Add a strong pullup option to the w1 system. This supplies extra power for parasite powered devices. There is a w1_master_pullup sysfs entry and enable_pullup module parameter to enable or disable the strong pullup. The one wire bus requires at a minimum one wire and ground. The common wire is used for sending and receiving data as well as supplying power to devices that are parasite powered of which temperature sensors can be one example. The bus must be idle and left high while a temperature conversion is in progress, in addition the normal pullup resister on larger networks or even higher temperatures might not supply enough power. The pullup resister can't provide too much pullup current, because devices need to pull the bus down to write a value. This enables the strong pullup for supported hardware, which can supply more current when requested. Unsupported hardware will just delay with the bus high. The hardware USB 2490 one wire bus master has a bit on some commands which will enable the strong pullup as soon as the command finishes executing. To use strong pullup, call the new w1_next_pullup function to register the duration. The next write command will call set_pullup before sending the data, and reset the duration to zero once it returns. Switched from simple_strtol to strict_strtol. Signed-off-by: David Fries <david@fries.net> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: w1_process, block or sleepDavid Fries
The w1_process thread's sleeping and termination has been modified. msleep_interruptible was replaced by schedule_timeout and schedule to allow for kthread_stop and wake_up_process to interrupt the sleep and the unbounded sleeping when a bus search is disabled. The W1_MASTER_NEED_EXIT and flags variable were removed as they were redundant with kthread_should_stop and kthread_stop. If w1_process is sleeping, requesting a search will immediately wake it up rather than waiting for the end of msleep_interruptible previously. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: don't delay search startDavid Fries
Move the creation of the w1_process thread to after the device has been initialized. This way w1_process doesn't have to check to see if it has been initialized and the bus search can proceed without sleeping. That also eliminates two checks in the w1_process loop. The sleep now happens at the end of the loop not the beginning. Also added a comment for why the atomic_set was 2. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-16W1: abort search early on on exitDavid Fries
Early abort if the master driver or the hardware goes away in the middle of a bus search operation. The alternative is to spam the print buffer up to 64*64 times with read errors in the case of USB. Signed-off-by: David Fries <david@fries.net> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>