Commit graph

211 commits

Author SHA1 Message Date
Alexander Sverdlin
e9b526fe70 i2c: suppress lockdep warning on delete_device
i2c: suppress lockdep warning on delete_device

Since commit 846f99749a the following lockdep
warning is thrown in case i2c device is removed (via delete_device sysfs
attribute) which contains subdevices (e.g. i2c multiplexer):

=============================================
[ INFO: possible recursive locking detected ]
3.8.7-0-sampleversion-fct #8 Tainted: G           O
---------------------------------------------
bash/3743 is trying to acquire lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8

but task is already holding lock:
  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208

other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(s_active#110);
   lock(s_active#110);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

4 locks held by bash/3743:
  #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff802b3c3c>] sysfs_write_file+0x4c/0x208
  #1:  (s_active#110){++++.+}, at: [<ffffffff802b3cb8>] sysfs_write_file+0xc8/0x208
  #2:  (&adap->userspace_clients_lock/1){+.+.+.}, at: [<ffffffff80454a18>] i2c_sysfs_delete_device+0x90/0x238
  #3:  (&__lockdep_no_validate__){......}, at: [<ffffffff803dcc24>] device_release_driver+0x24/0x48

stack backtrace:
Call Trace:
[<ffffffff80575cc8>] dump_stack+0x8/0x34
[<ffffffff801b50fc>] __lock_acquire+0x161c/0x2110
[<ffffffff801b5c3c>] lock_acquire+0x4c/0x70
[<ffffffff802b60cc>] sysfs_addrm_finish+0x19c/0x1e0
[<ffffffff802b3048>] sysfs_hash_and_remove+0x58/0xc8
[<ffffffff802b7d8c>] sysfs_remove_group+0x64/0x148
[<ffffffff803d990c>] device_remove_attrs+0x9c/0x1a8
[<ffffffff803d9b1c>] device_del+0x104/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff8045505c>] i2c_del_adapter+0x1cc/0x328
[<ffffffff8045802c>] i2c_del_mux_adapter+0x14/0x38
[<ffffffffc025c108>] pca954x_remove+0x90/0xe0 [pca954x]
[<ffffffff804542f8>] i2c_device_remove+0x80/0xe8
[<ffffffff803dca9c>] __device_release_driver+0x74/0xf8
[<ffffffff803dcc2c>] device_release_driver+0x2c/0x48
[<ffffffff803dbc14>] bus_remove_device+0x13c/0x1d8
[<ffffffff803d9b24>] device_del+0x10c/0x1d8
[<ffffffff803d9c18>] device_unregister+0x28/0x70
[<ffffffff80454b08>] i2c_sysfs_delete_device+0x180/0x238
[<ffffffff802b3cd4>] sysfs_write_file+0xe4/0x208
[<ffffffff8023ddc4>] vfs_write+0xbc/0x160
[<ffffffff8023df6c>] SyS_write+0x54/0xd8
[<ffffffff8013d424>] handle_sys64+0x44/0x64

The problem is already known for USB and PCI subsystems. The reason is that
delete_device attribute is defined statically in i2c-core.c and used for all
devices in i2c subsystem.

Discussion of original USB problem:
http://lkml.indiana.edu/hypermail/linux/kernel/1204.3/01160.html

Commit 356c05d58a introduced new macro to suppress
lockdep warnings for this special case and included workaround for USB code.

LKML discussion of the workaround:
http://lkml.indiana.edu/hypermail/linux/kernel/1205.1/03634.html

As i2c case is in principle the same, the same workaround could be used here.

Signed-off-by: Alexander Sverdlin <alexander.sverdlin@nsn.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-05-17 22:49:45 +02:00
Yijing Wang
e5a7074a75 i2c: remove CONFIG_HOTPLUG ifdefs
CONFIG_HOTPLUG is going away as an option, cleanup CONFIG_HOTPLUG
ifdefs in i2c files.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-09 11:57:55 +02:00
Lars-Peter Clausen
71546300c8 i2c: Make return type of i2c_del_adapter() void
i2c_del_adapter() is usually called from a drivers remove callback. The Linux
device driver model does not allow the remove callback to fail and all resources
allocated in the probe callback need to be freed, as well as all resources which
have been provided to the rest of the kernel(for example a I2C adapter) need to
be revoked. So any function revoking such resources isn't allowed to fail
either. i2c_del_adapter() adheres to this requirement and will never fail. But
i2c_del_adapter()'s return type is int, which may cause driver authors to think
that it can fail. This led to code constructs like:

	ret = i2c_del_adapter(...);
	BUG_ON(ret);

Since i2c_del_adapter() always returns 0 the BUG_ON is never hit and essentially
becomes dead code, which means it can be removed. Making the return type of
i2c_del_adapter() void makes it explicit that the function will never fail and
should prevent constructs like the above from re-appearing in the kernel code.

All callers of i2c_del_adapter() have already been updated in a previous patch
to ignore the return value, so the conversion of the return type from int to
void can be done without causing any build failures.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:06:17 +02:00
Lars-Peter Clausen
f5fb082295 i2c: i2c_del_adapter: Don't treat removing a non-registered adapter as error
Currently i2c_del_adapter() returns -EINVAL when it gets an adapter which is not
registered. But none of the users of i2c_del_adapter() depend on this behavior,
so for the sake of being able to sanitize the return type of i2c_del_adapter
argue, that the purpose of i2c_del_adapter() is to remove an I2C adapter from
the system. If the adapter is not registered in the first place this becomes a
no-op. So we can return success without having to do anything.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:03:37 +02:00
Lars-Peter Clausen
19baba4cb6 i2c: Remove detach_adapter
The detach_adapter callback has been deprecated for quite some time and has no
user left. Keeping it alive blocks other cleanups, so remove it.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-04-02 07:03:28 +02:00
Viresh Kumar
5f9296ba21 i2c: Add bus recovery infrastructure
Add i2c bus recovery infrastructure to i2c adapters as specified in the i2c
protocol Rev. 03 section 3.1.16 titled "Bus clear".

http://www.nxp.com/documents/user_manual/UM10204.pdf

Sometimes during operation i2c bus hangs and we need to give dummy clocks to
slave device to start the transfer again. Now we may have capability in the bus
controller to generate these clocks or platform may have gpio pins which can be
toggled to generate dummy clocks. This patch supports both.

This patch also adds in generic bus recovery routines gpio or scl line based
which can be used by bus controller. In addition controller driver may provide
its own version of the bus recovery routine.

This doesn't support multi-master recovery for now.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
[wsa: changed gpio type to int and minor reformatting]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24 10:30:54 +01:00
Doug Anderson
ee5c27440c i2c: core: Pick i2c bus number from dt alias if present
This allows you to get the equivalent functionality of
i2c_add_numbered_adapter() with all data in the device tree and no
special case code in your driver.  This is a common device tree
technique.

For quick reference, the FDT syntax for using an alias to provide an
ID looks like:
  aliases {
    i2c0 = &i2c_0;
    i2c1 = &i2c_1;
  };

Signed-off-by: Doug Anderson <dianders@chromium.org>
[wsa: removed one check from static function. We know our callers]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2013-03-24 10:30:53 +01:00
Tejun Heo
e8c8d1bc06 idr: remove MAX_IDR_MASK and move left MAX_IDR_* into idr.c
MAX_IDR_MASK is another weirdness in the idr interface.  As idr covers
whole positive integer range, it's defined as 0x7fffffff or INT_MAX.

Its usage in idr_find(), idr_replace() and idr_remove() is bizarre.
They basically mask off the sign bit and operate on the rest, so if
the caller, by accident, passes in a negative number, the sign bit
will be masked off and the remaining part will be used as if that was
the input, which is worse than crashing.

The constant is visible in idr.h and there are several users in the
kernel.

* drivers/i2c/i2c-core.c:i2c_add_numbered_adapter()

  Basically used to test if adap->nr is a negative number which isn't
  -1 and returns -EINVAL if so.  idr_alloc() already has negative
  @start checking (w/ WARN_ON_ONCE), so this can go away.

* drivers/infiniband/core/cm.c:cm_alloc_id()
  drivers/infiniband/hw/mlx4/cm.c:id_map_alloc()

  Used to wrap cyclic @start.  Can be replaced with max(next, 0).
  Note that this type of cyclic allocation using idr is buggy.  These
  are prone to spurious -ENOSPC failure after the first wraparound.

* fs/super.c:get_anon_bdev()

  The ID allocated from ida is masked off before being tested whether
  it's inside valid range.  ida allocated ID can never be a negative
  number and the masking is unnecessary.

Update idr_*() functions to fail with -EINVAL when negative @id is
specified and update other MAX_IDR_MASK users as described above.

This leaves MAX_IDR_MASK without any user, remove it and relocate
other MAX_IDR_* constants to lib/idr.c.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Roland Dreier <roland@kernel.org>
Cc: Sean Hefty <sean.hefty@intel.com>
Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: "Marciniszyn, Mike" <mike.marciniszyn@intel.com>
Cc: Jack Morgenstein <jackm@dev.mellanox.co.il>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Wolfram Sang <wolfram@the-dreams.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:20 -08:00
Tejun Heo
4ae42b0ff0 i2c: convert to idr_alloc()
Convert to the much saner new idr interface.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Wolfram Sang <wolfram@the-dreams.de>
Tested-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:16 -08:00
Tushar Behera
c811093320 i2c: core: Remove definition of i2c_smbus_process_call
i2c_smbus_process_call has no users in the kernel, so this can be
removed. Documentation for the same has been updated accordingly.

Fixes following sparse warning.
drivers/i2c/i2c-core.c:1871:5: warning: symbol 'i2c_smbus_process_call'
was not declared. Should it be static?

[wsa: updated the documentation]

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2013-01-28 05:26:41 +01:00
Mika Westerberg
907ddf89d0 i2c / ACPI: add ACPI enumeration support
ACPI 5 introduced I2cSerialBus resource that makes it possible to enumerate
and configure the I2C slave devices behind the I2C controller. This patch
adds helper functions to support I2C slave enumeration.

An ACPI enabled I2C controller driver only needs to call acpi_i2c_register_devices()
in order to get its slave devices enumerated, created and bound to the
corresponding ACPI handle.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2012-11-23 12:23:40 +01:00
Shubhrajyoti D
230da09435 i2c: Convert struct i2c_msg initialization to C99 format
Convert the struct i2c_msg initialization to C99 format. This makes
maintaining and editing the code simpler. Also helps once other fields
like transferred are added in future.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-10-05 22:23:52 +02:00
Fengguang Wu
125c4c706b idr: rename MAX_LEVEL to MAX_IDR_LEVEL
To avoid name conflicts:

  drivers/video/riva/fbdev.c:281:9: sparse: preprocessor token MAX_LEVEL redefined

While at it, also make the other names more consistent and add
parentheses.

[akpm@linux-foundation.org: repair fallout]
[sfr@canb.auug.org.au: IB/mlx4: fix for MAX_ID_MASK to MAX_IDR_MASK name change]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Bernd Petrovitsch <bernd@petrovitsch.priv.at>
Cc: walter harms <wharms@bfs.de>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Roland Dreier <roland@purestorage.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-06 03:04:56 +09:00
Jean Delvare
390946b172 i2c-core: Fix for lockdep validator
If kernel is compiled with CONFIG_PROVE_LOCKING the
validator raises an error when a multiplexer is removed
via sysfs and sub-clients are connected to it. This is a
false positive.
Documentation/lockdep-design.txt recommends to handle this
via calls to mutex_lock_nested().

Based on an earlier fix from Michael Lawnick.

Note that the extra code resolves to nothing unless
CONFIG_DEBUG_LOCK_ALLOC=y.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
2012-09-10 10:14:02 +02:00
Linus Torvalds
6df419e45d Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab:
 "This is the first part of the media patches for v3.6.

  This patch series contain:
   - new DVB frontend: rtl2832
   - new video drivers: adv7393
   - some unused files got removed
   - a selection API cleanup between V4L2 and V4L2 subdev API's
   - a major redesign at v4l-ioctl2, in order to clean it up
   - several driver fixes and improvements."

* 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (174 commits)
  v4l: Export v4l2-common.h in include/linux/Kbuild
  media: Revert "[media] Terratec Cinergy S2 USB HD Rev.2"
  [media] media: Use pr_info not homegrown pr_reg macro
  [media] Terratec Cinergy S2 USB HD Rev.2
  [media] v4l: Correct conflicting V4L2 subdev selection API documentation
  [media] Feature removal: V4L2 selections API target and flag definitions
  [media] v4l: Unify selection flags documentation
  [media] v4l: Unify selection flags
  [media] v4l: Common documentation for selection targets
  [media] v4l: Unify selection targets across V4L2 and V4L2 subdev interfaces
  [media] v4l: Remove "_ACTUAL" from subdev selection API target definition names
  [media] V4L: Remove "_ACTIVE" from the selection target name definitions
  [media] media: dvb-usb: print mac address via native %pM
  [media] s5p-tv: Use module_i2c_driver in sii9234_drv.c file
  [media] media: gpio-ir-recv: add allowed_protos for platform data
  [media] s5p-jpeg: Use module_platform_driver in jpeg-core.c file
  [media] saa7134: fix spelling of detach in label
  [media] cx88-blackbird: replace ioctl by unlocked_ioctl
  [media] cx88: don't use current_norm
  [media] cx88: fix a number of v4l2-compliance violations
  ...
2012-07-30 19:03:41 -07:00
Laurent Pinchart
72fc2c7f78 i2c: Fall back to emulated SMBus if the operation isn't supported natively
Adapter drivers might support only a subset of the SMBus operations
natively. Those drivers currently have to manually emulate unsupported
operations using I2C.

Make the i2c_smbus_xfer() function fall back to
i2c_smbus_xfer_emulated() when the adapter's .smbus_xfer() operation
returns -EOPNOTSUPP, like it already does when the .smbus_xfer()
operation isn't available at all.

[JD: Minor optimization.]

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:59 +02:00
Laurent Pinchart
d47726c521 i2c: Add SCCB support
SCCB is a serial communication bus developed by Omnivision. Its 2-wire
mode is very similar to SMBus byte data transactions, but requires the
controller to ignore the ACK bit and to insert a stop condition after
each message.

Add a device SCCB flag and a message stop flag to be passed to
controller drivers.

[JD: Kill rogue definition in go7007 driver.]

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-07-24 14:13:59 +02:00
Jean Delvare
b37d2a3a75 [media] i2c: Export an unlocked flavor of i2c_transfer
Some drivers (in particular for TV cards) need exclusive access to
their I2C buses for specific operations. Export an unlocked flavor
of i2c_transfer to give them full control.

The unlocked flavor has the following limitations:
* Obviously, caller must hold the i2c adapter lock.
* No debug messages are logged. We don't want to log messages while
  holding a rt_mutex.
* No check is done on the existence of adap->algo->master_xfer. It
  is thus the caller's responsibility to ensure that the function is
  OK to call.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2012-06-29 19:03:25 -03:00
Stephen Warren
643dd09eb2 i2c: implement i2c_verify_adapter
This converts a struct device * to a struct i2c_adapter * while verifying
that the device really is an I2C adapter. Just like i2c_verify_client.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
2012-05-12 14:28:16 +02:00
Jean Delvare
5694f8a888 i2c: Update the FSF address
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-03-26 21:47:19 +02:00
Wolfram Sang
834aa6f30c i2c-core: Comment says "transmitted" but means "received"
Fix that. Also convert this and the related comment to proper commenting
style.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2012-03-15 18:11:05 +01:00
Jean Delvare
cbb4451404 i2c: Fix device name for 10-bit slave address
10-bit addresses overlap with traditional 7-bit addresses, leading in
device name collisions. Add an arbitrary offset to 10-bit addresses to
prevent this collision. The offset was chosen so that the address is
still easily recognizable.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2011-11-23 11:33:07 +01:00
Grant Likely
488bf314bf i2c: Allow i2c_add_numbered_adapter() to assign a bus id
Currently, if an i2c bus driver supports both static and dynamic bus
ids, it needs to choose between calling i2c_add_numbered_adapter() and
i2c_add_adapter().  This patch makes i2c_add_numbered_adapter()
redirect to i2c_add_adapter() if the requested bus id is -1.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-07-25 17:49:43 +02:00
Jean Delvare
a920ff41cb i2c: Improve deprecation warnings
When warning on the use of deprecated i2c_driver methods
attach_adapter and detach_adapter, mention the name of the driver
which needs to be updated.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2011-04-17 10:20:19 +02:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Jean Delvare
fe6fc25857 i2c: Deprecate i2c_driver.attach_adapter and .detach_adapter
The last legitimate user of i2c_driver.attach_adapter and
.detach_adapter is gone, so we can finally deprecate these callbacks.
The last few drivers which still use these will have to be updated to
make use of standard I2C device instantiation ways instead.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:53 +01:00
Jean Delvare
7ae31482a8 i2c: Export i2c_for_each_dev
Introduce i2c_for_each_dev(), an i2c device iterator with proper
locking for use by i2c-dev. This is needed so that we can get rid of
the attach_adapter and detach_adapter legacy callback functions.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Jean Delvare
d735b34db3 i2c: make i2c_get_adapter prototype clearer
Rename the parameter of i2c_get_adapter() to "nr", to make it clear we
are passing an adapter number and not an adapter ID (which have gone
away by now.)

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-03-20 14:50:52 +01:00
Grant Likely
c9e358dfc4 driver-core: remove conditionals around devicetree pointers
Having conditional around the of_match_table and the of_node pointers
turns out to make driver code use ugly #ifdef blocks.  Drop the
conditionals and remove the #ifdef blocks from the affected drivers.

Also tidy up minor whitespace issues within the same hunks.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-01-21 09:24:48 -07:00
Mark Brown
f4e8db31a8 i2c: Encourage move to dev_pm_ops by warning on use of legacy methods
Since the PM core wishes to transition away from the legacy suspend
and resume methods and since removing them makes using PM core features
like runtime PM much easier start warning when a driver is registered
using the legacy methods.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-14 22:03:50 +01:00
Mark Brown
d529de2994 i2c: Factor out runtime suspend checks from PM operations
When devices use dev_pm_ops the I2C API is implementing standard functionality
for integration with runtime PM and for checking for the presence of a per
device op. The PM core provides pm_generic_ functions implementing this
behaviour - use them to reduce coupling with future PM updates.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-14 22:03:49 +01:00
Jean Delvare
5219bf884b i2c: Unregister dummy devices last on adapter removal
Remove real devices first and dummy devices last. This gives device
driver which instantiated dummy devices themselves a chance to clean
them up before we do.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Hans Verkuil <hverkuil@xs4all.nl>
Cc: stable@kernel.org
2011-01-14 22:03:49 +01:00
Jean Delvare
0cc43a1806 i2c: Constify i2c_client where possible
Helper functions for I2C and SMBus transactions don't modify the
i2c_client that is passed to them, so it can be marked const.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2011-01-10 22:11:23 +01:00
Jean Delvare
2236baa75f i2c: Sanity checks on adapter registration
Make sure I2C adapters being registered have the required struct
fields set. If they don't, problems will happen later.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-11-15 22:40:38 +01:00
Jean Delvare
51b54ba9bb i2c: Optimize function i2c_detect()
Check the class flags before allocating the temporary i2c_client
structure, to avoid allocating it when we don't need it.

Also optimize the inner loop a bit.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
2010-10-24 18:16:58 +02:00
Jean Delvare
d57558d0f3 i2c: Discard warning message on device instantiation from user-space
The "new_device" sysfs interface has been there for quite some time
now, nobody complained about it so it must be good enough. Time to
remove the warning and call it stable.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Michael Lawnick <ml.lawnick@gmx.de>
2010-10-24 18:16:58 +02:00
Jean Delvare
97cc4d49cf i2c: Let i2c_parent_is_i2c_adapter return the parent adapter
This makes the calling site's code clearer IMHO.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Michael Lawnick <ml.lawnick@gmx.de>
2010-10-24 18:16:57 +02:00
Grant Likely
925bb9c649 of/i2c: Fix module load order issue caused by of_i2c.c
Commit 959e85f7, "i2c: add OF-style registration and binding" caused a
module dependency loop where of_i2c.c calls functions in i2c-core, and
i2c-core calls of_i2c_register_devices() in of_i2c.  This means that
when i2c support is built as a module when CONFIG_OF is set, then
neither i2c_core nor of_i2c are able to be loaded.

This patch fixes the problem by moving the of_i2c_register_devices()
calls back into the device drivers.  Device drivers already
specifically request the core code to parse the device tree for
devices anyway by setting the of_node pointer, so it isn't a big
deal to also call the registration function.  The drivers just become
slightly more verbose.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-09-30 14:14:23 +02:00
Rajendra Nayak
64b4782fc9 i2c: Fix checks which cause legacy suspend to never get called
For devices which are not adapted to runtime PM a call to
pm_runtime_suspended always returns true.

Hence the pm_runtime_suspended checks below prevent legacy
suspend from getting called.

So do a pm_runtime_suspended check only for devices with a
dev_pm_ops populated (which hence do not rely on the legacy
suspend.)

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-09-30 14:14:22 +02:00
Vishwanath BS
753419f59e i2c: Fix for suspend/resume issue
In current i2c core driver, call to pm_runtime_set_active from
i2c_device_pm_resume will unconditionally enable i2c module and
increment child count of the parent. Because of this, in CPU Idle
path, i2c does not idle, preventing Core to enter retention. Also i2c
module will not be suspended upon system suspend as
pm_runtime_set_suspended is not called from i2c_device_pm_suspend.

This issue is fixed by removing pm_runtime_set_active call from resume
path which is not necessary.
This fix has been tested on OMAP4430.

Signed-off-by: Partha Basak <p-basak2@ti.com>
Signed-off-by: Vishwanath BS <vishwanath.bs@ti.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-09-30 14:14:22 +02:00
Michael Lawnick
0826374bff i2c: Multiplexed I2C bus core support
Add multiplexed bus core support. I2C multiplexer and switches
like pca954x get instantiated as new adapters per port.

Signed-off-by: Michael Lawnick <ml.lawnick@gmx.de>
Acked-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-08-11 18:21:02 +02:00
Jean Delvare
dafc50d141 i2c: Use a separate mutex for userspace client lists
Moving userspace-instantiated clients to separate lists wasn't nearly
enough to avoid deadlocks in multiplexed bus cases. We also want to
have a dedicated mutex to protect each list.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
2010-08-11 18:21:01 +02:00
Jean Delvare
8031d79bae i2c: Make i2c_default_probe self-sufficient
Make i2c_default_probe self-sufficient, so that callers don't have to
do functionality checks themselves. This ensures everything is and
will stay consistent.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-08-11 18:21:00 +02:00
Jean Delvare
d6703281ff i2c: Drop dummy variable
Now that bus_for_each_drv() is no longer __must_check, we can drop the
dummy variable that was used to store the returned value.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Justin P. Mattock <justinmattock@gmail.com>
2010-08-11 18:20:59 +02:00
Jean Delvare
fe61e07e9e i2c: Move adapter locking helpers to i2c-core
Uninline i2c adapter locking helper functions, move them to i2c-core,
and use them in i2c-core itself. The functions are still exported for
external users. This makes future updates to the locking model (which
will be needed for multiplexing support) possible and transparent.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Lawnick <ml.lawnick@gmx.de>
2010-08-11 18:20:58 +02:00
Jean Delvare
d44f19d586 V4L/DVB: Use custom I2C probing function mechanism
Now that i2c-core offers the possibility to provide custom probing
function for I2C devices, let's make use of it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-08-11 18:20:57 +02:00
Jean Delvare
9a94241afc i2c: Add support for custom probe function
The probe method used by i2c_new_probed_device() may not be suitable
for all cases. Let the caller provide its own, optional probe
function.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2010-08-11 18:20:56 +02:00
Grant Likely
4e4f62bf73 Merge commit 'v2.6.35-rc6' into devicetree/next
Conflicts:
	arch/sparc/kernel/prom_64.c
2010-07-24 09:49:13 -06:00
Jean Delvare
827900c556 i2c: Fix probability check
The new unified probing function differs from the original code, and
the preliminary test whether probing is possible must be updated
accordingly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-07-10 09:42:46 +02:00
Grant Likely
959e85f775 i2c: Add OF-style registration and binding
This patch adds OF hooks to the i2c core so that devices can automatically
be registered based on device tree data.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-07-05 16:14:52 -06:00