Commit Graph

183 Commits

Author SHA1 Message Date
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
Jean Delvare
3b5f794b8b i2c: Rename i2c_check_addr to i2c_check_addr_busy
Otherwise it's not clear what it is checking.

Also move the function to save a forward declaration.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-06-03 11:33:55 +02:00
Jean Delvare
656b8761ab i2c: Document reserved I2C addresses
Move strict I2C address validity check to a single function, and
document the reserved I2C addresses there.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Hans Verkuil <hverkuil@xs4all.nl>
2010-06-03 11:33:53 +02:00
Jean Delvare
3a89db5f30 i2c: Check for address validity on client registration
Do basic address validity checks when a client is being registered. We
already had checks in place for devices which are being detected, but
not for devices which are simply instantiated.

This is a very basic check. We don't want to do strict checking here
because some devices are known to infringe the I2C address constraints
(e.g. IR receivers at 7-bit address 0x7a while this value is
supposedly reserved for 10-bit addresses.) So we assume the caller
knows what it is doing.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
2010-06-03 11:33:52 +02:00
Jean Delvare
63e4e80218 i2c: Share the I2C device presence detection code
Use the same I2C device presence detection code for legacy and new
device detection functions. This is more consistent and makes the code
smaller.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Matthieu Castet <castet.matthieu@free.fr>
2010-06-03 11:33:51 +02:00
Grant Likely
cf9b59e9d3 Merge remote branch 'origin' into secretlab/next-devicetree
Merging in current state of Linus' tree to deal with merge conflicts and
build failures in vio.c after merge.

Conflicts:
	drivers/i2c/busses/i2c-cpm.c
	drivers/i2c/busses/i2c-mpc.c
	drivers/net/gianfar.c

Also fixed up one line in arch/powerpc/kernel/vio.c to use the
correct node pointer.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-05-22 00:36:56 -06:00
Farid Hammane
7225acf4aa i2c-core: Fix some coding style issues
Fix up coding style issues found by the checkpatch.pl tool.

Signed-off-by: Farid Hammane <farid.hammane@gmail.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-05-21 18:40:58 +02:00
Rafael J. Wysocki
2f60ba706b i2c: Fix bus-level power management callbacks
There are three issues with the i2c bus type's power management
callbacks at the moment.  First, they don't include any hibernate
callbacks, although they should at least include the .restore()
callback (there's no guarantee that the driver will be present in
memory before loading the image kernel and we must restore the
pre-hibernation state of the device).  Second, the "legacy"
callbacks are not going to be invoked by the PM core since the bus
type's pm object is not NULL.  Finally, the system sleep PM
(ie. suspend/resume) callbacks don't check if the device has been
already suspended at run time, in which case they should skip
suspending it.  Also, it looks like the i2c bus type can use the
generic subsystem-level runtime PM callbacks.

For these reasons, rework the system sleep PM callbacks provided by
the i2c bus type to handle hibernation correctly and to invoke the
"legacy" callbacks for drivers that provide them.  In addition to
that make the i2c bus type use the generic subsystem-level runtime
PM callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
2010-05-10 23:09:30 +02:00
Jean Delvare
6629dcff19 i2c-core: Use per-adapter userspace device lists
Using a single list for all userspace devices leads to a dead lock
on multiplexed buses in some circumstances (mux chip instantiated
from userspace). This is solved by using a separate list for each
bus segment.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Michael Lawnick <ml.lawnick@gmx.de>
2010-05-04 11:09:28 +02:00
Jean Delvare
b1d4b390ea i2c: Fix probing of FSC hardware monitoring chips
Some FSC hardware monitoring chips (Syleus at least) doesn't like
quick writes we typically use to probe for I2C chips. Use a regular
byte read instead for the address they live at (0x73). These are the
only known chips living at this address on PC systems.

For clarity, this fix should not be needed for kernels 2.6.30 and
later, as we started instantiating the hwmon devices explicitly based
on DMI data. Still, this fix is valuable in the following two cases:
* Support for recent FSC chips on older kernels. The DMI-based device
  instantiation is more difficult to backport than the device support
  itself.
* Case where the DMI-based device instantiation fails, whatever the
  reason. We fall back to probing in that case, so it should work.

This fixes kernel bug #15634:
https://bugzilla.kernel.org/show_bug.cgi?id=15634

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Cc: stable@kernel.org
2010-05-04 11:09:28 +02:00
Wolfram Sang
e4a7b9b04d i2c-core: Erase pointer to clientdata on removal
After discovering that a lot of i2c-drivers leave the pointer to their
clientdata dangling, it was decided to let the core handle this issue.
It is assumed that the core may access the private data after remove()
as there are no guarantees for the lifetime of such pointers anyhow (see
thread starting at http://lkml.org/lkml/2010/3/21/68)

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-05-04 11:09:27 +02:00
Grant Likely
d12d42f744 i2c/of: Allow device node to be passed via i2c_board_info
The struct device_node *of_node pointer is moving out of dev->archdata
and into the struct device proper.  of_i2c.c needs to set the of_node
pointer before the device is registered.  Since the i2c subsystem
doesn't allow 2 stage allocation and registration of i2c devices, the
of_node pointer needs to be passed via the i2c_board_info structure
so that it is set prior to registration.

This patch adds of_node to struct i2c_board_info (conditional on
CONFIG_OF), sets of_node in i2c_new_device(), and modifies of_i2c.c
to use the new parameter.  The calling of dev_archdata_set_node()
from of_i2c will be removed in a subsequent patch when of_node is
removed from archdata and all users are converted over.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-04-28 18:21:56 -06:00
Zhangfei Gao
0c43ea544c i2c: Document the message size limit
i2c_master_send & i2c_master_recv do not support more than 64 kb
transfer, since msg.len is u16.

Signed-off-by: Zhangfei Gao <zgao6@marvell.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-03-02 12:23:49 +01:00
Mark Brown
6de468ae2d i2c: Hook up runtime PM support
Allow I2C drivers to make use of the runtime PM framework by adding
bus implementations of the runtime PM operations. These simply
immediately suspend when the device is idle. The runtime PM framework
provides drivers with off the shelf refcounts for enables and sysfs
control for managing runtime suspend from userspace so is useful even
without meaningful input from the bus.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-03-02 12:23:46 +01:00
Thadeu Lima de Souza Cascardo
c556752109 i2c: Do not use device name after device_unregister
dev_dbg outputs dev_name, which is released with device_unregister. This bug
resulted in output like this:

i2c Xy2�0: adapter [SMBus I801 adapter at 1880] unregistered

The right output would be:
i2c i2c-0: adapter [SMBus I801 adapter at 1880] unregistered

Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-01-16 20:43:13 +01:00
Tobias Klauser
0b2c368844 i2c-core: Storage class should be before const qualifier
The C99 specification states in section 6.11.5:

The placement of a storage-class specifier other than at the beginning
of the declaration specifiers in a declaration is an obsolescent
feature.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2010-01-16 20:43:12 +01:00
sonic zhang
54067ee206 i2c-core: i2c bus should support PM entries in struct dev_pm_ops
Struct dev_pm_ops is not configured in current i2c bus type. i2c drivers
only depends on suspend/resume entries in struct dev_pm_ops are not
informed of PM suspend and resume events by i2c framework.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-14 21:17:30 +01:00
Jean Delvare
c3813d6af1 i2c: Get rid of struct i2c_client_address_data
Struct i2c_client_address_data only contains one field at this point,
which makes its usefulness questionable. Get rid of it and pass simple
address lists around instead.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-12-14 21:17:25 +01:00
Jean Delvare
310ec79210 i2c: Drop the kind parameter from detect callbacks
The "kind" parameter always has value -1, and nobody is using it any
longer, so we can remove it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-12-14 21:17:23 +01:00
Jean Delvare
69b0089a67 i2c: Refactor for_each callbacks
Functions i2c_do_add_adapter() and __attach_adapter() do essentially
the same thing, differing only in how the parameters are passed. Same
for i2c_do_add_adapter() and __detach_adapter(). Introduce wrappers to
normalize the parameters, so that we do not have to duplicate the
code.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-12-06 17:06:27 +01:00
Jean Delvare
ccfbbd082a i2c: Simplify i2c_detect_address
The kind parameter of i2c_detect_address() always has value -1, so we
can get rid of it.

Next step is to update all i2c detect callback functions to get rid of
this now useless parameter.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:25 +01:00
Jean Delvare
c7b25a9e96 i2c: Drop probe, ignore and force module parameters
The legacy probe and force module parameters are obsolete now, the
same can be achieved using the new_device sysfs interface, which is
both more flexible and cheaper (it is implemented by i2c-core rather
than replicated in every driver module.)

The legacy ignore module parameters can be dropped as well. Ignoring
can be done by instantiating a "dummy" device at the problematic
address.

This is the first step of a huge cleanup to i2c-core's i2c_detect
function, i2c.h's I2C_CLIENT_INSMOD* macros, and all drivers that made
use of them.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:24 +01:00
Mika Kuoppala
194684e596 i2c: Prevent priority inversion on top of bus lock
Low priority thread holding the i2c bus mutex could block higher
priority threads to access the bus resulting in unacceptable
latencies. Change the mutex type to rt_mutex preventing priority
inversion.

Tested-by: Peter Ujfalusi <peter.ujfalusi@nokia.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@nokia.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-12-06 17:06:22 +01:00
Jean Delvare
bbd2d9c919 i2c: Fix userspace_device list corruption
Fix userspace_device list corruption. The corruption was caused by
clients not being removed when adapters with such clients were
themselves removed. Something like the following would trigger it
(assuming i2c-stub gets adapter number 3):

# modprobe i2c-stub chip_addr=0x50
# echo 24c08 0x50 > /sys/bus/i2c/devices/i2c-3/new_device 
# rmmod i2c-stub
# modprobe i2c-stub chip_addr=0x50
# echo 24c08 0x50 > /sys/bus/i2c/devices/i2c-3/new_device 

For the records, the stack trace in the kernel logs look like this:

kernel: WARNING: at lib/list_debug.c:30 __list_add+0x8b/0x90()
kernel: Hardware name: (...)
kernel: list_add corruption. prev->next should be next (c137fc84), but was (null). (prev=f57111b8).
kernel: Modules linked in: (...)
kernel: Pid: 4669, comm: bash Not tainted 2.6.32-rc8 #259
kernel: Call Trace:
kernel:  [<c111eb8b>] ? __list_add+0x8b/0x90
kernel:  [<c111eb8b>] ? __list_add+0x8b/0x90
kernel:  [<c103265c>] warn_slowpath_common+0x6c/0xc0
kernel:  [<c111eb8b>] ? __list_add+0x8b/0x90
kernel:  [<c10326f6>] warn_slowpath_fmt+0x26/0x30
kernel:  [<c111eb8b>] __list_add+0x8b/0x90
kernel:  [<c11ba165>] i2c_sysfs_new_device+0x1c5/0x250
kernel:  [<c10861be>] ? might_fault+0x2e/0x80
kernel:  [<c11b9fa0>] ? i2c_sysfs_new_device+0x0/0x250
kernel:  [<c118c625>] dev_attr_store+0x25/0x30
kernel:  [<c10e305c>] sysfs_write_file+0x9c/0xf0
kernel:  [<c109d35c>] vfs_write+0x9c/0x160
kernel:  [<c10e2fc0>] ? sysfs_write_file+0x0/0xf0
kernel:  [<c109d4dd>] sys_write+0x3d/0x70
kernel:  [<c1002ed8>] sysenter_do_call+0x12/0x36

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-11-26 09:22:33 +01:00
Jean Delvare
2bb5095aff i2c: Provide compatibility links for i2c adapters
Some user-space applications may be relying on i2c adapters showing up
as class devices in sysfs. Provide compatibility links for them for
the time being. We will remove them after a long transition period.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
2009-09-18 22:45:46 +02:00
Jean Delvare
4f8cf8240a i2c: Convert i2c adapters to bus devices
Kay says i2c adapters shouldn't be class devices but bus devices.
Convert them that way, using a device type.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
2009-09-18 22:45:46 +02:00
Jean Delvare
51298d1257 i2c: Convert i2c clients to a device type
This is required for upcoming changes.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
2009-09-18 22:45:45 +02:00
Rodolfo Giometti
f18c41daea i2c: Use rwsem instead of mutex for board info
By using rwsem we can easily manage recursive calls of
i2c_scan_static_board_info() function without breaking the locking.

Signed-off-by: Rodolfo Giometti <giometti@linux.it>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-19 16:58:20 +02:00
Jean Delvare
99cd8e2587 i2c: Add a sysfs interface to instantiate devices
Add a sysfs interface to instantiate and delete I2C devices. This is
primarily a replacement of the force_* module parameters implemented
by some i2c drivers. These module parameters were implemented
internally by the I2C_CLIENT_INSMOD* macros, which don't scale well.

This can also be used when developing a driver on a self-soldered
board which doesn't yet have proper I2C device declaration at the
platform level, and presumably for various debugging situations.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19 16:58:20 +02:00