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path: root/drivers/i2c/i2c-core.c
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2010-08-11i2c: Multiplexed I2C bus core supportMichael Lawnick
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>
2010-08-11i2c: Use a separate mutex for userspace client listsJean Delvare
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>
2010-08-11i2c: Make i2c_default_probe self-sufficientJean Delvare
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>
2010-08-11i2c: Drop dummy variableJean Delvare
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>
2010-08-11i2c: Move adapter locking helpers to i2c-coreJean Delvare
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>
2010-08-11V4L/DVB: Use custom I2C probing function mechanismJean Delvare
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>
2010-08-11i2c: Add support for custom probe functionJean Delvare
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>
2010-07-24Merge commit 'v2.6.35-rc6' into devicetree/nextGrant Likely
Conflicts: arch/sparc/kernel/prom_64.c
2010-07-10i2c: Fix probability checkJean Delvare
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>
2010-07-05i2c: Add OF-style registration and bindingGrant Likely
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>
2010-06-03i2c: Rename i2c_check_addr to i2c_check_addr_busyJean Delvare
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>
2010-06-03i2c: Document reserved I2C addressesJean Delvare
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>
2010-06-03i2c: Check for address validity on client registrationJean Delvare
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>
2010-06-03i2c: Share the I2C device presence detection codeJean Delvare
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>
2010-05-22Merge remote branch 'origin' into secretlab/next-devicetreeGrant Likely
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>
2010-05-21i2c-core: Fix some coding style issuesFarid Hammane
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>
2010-05-10i2c: Fix bus-level power management callbacksRafael J. Wysocki
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>
2010-05-04i2c-core: Use per-adapter userspace device listsJean Delvare
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>
2010-05-04i2c: Fix probing of FSC hardware monitoring chipsJean Delvare
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
2010-05-04i2c-core: Erase pointer to clientdata on removalWolfram Sang
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>
2010-04-28i2c/of: Allow device node to be passed via i2c_board_infoGrant Likely
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>
2010-03-02i2c: Document the message size limitZhangfei Gao
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>
2010-03-02i2c: Hook up runtime PM supportMark Brown
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>
2010-01-16i2c: Do not use device name after device_unregisterThadeu Lima de Souza Cascardo
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>
2010-01-16i2c-core: Storage class should be before const qualifierTobias Klauser
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>
2009-12-14i2c-core: i2c bus should support PM entries in struct dev_pm_opssonic zhang
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>
2009-12-14i2c: Get rid of struct i2c_client_address_dataJean Delvare
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>
2009-12-14i2c: Drop the kind parameter from detect callbacksJean Delvare
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>
2009-12-06i2c: Refactor for_each callbacksJean Delvare
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>
2009-12-06i2c: Simplify i2c_detect_addressJean Delvare
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>
2009-12-06i2c: Drop probe, ignore and force module parametersJean Delvare
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>
2009-12-06i2c: Prevent priority inversion on top of bus lockMika Kuoppala
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>
2009-11-26i2c: Fix userspace_device list corruptionJean Delvare
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>
2009-09-18i2c: Provide compatibility links for i2c adaptersJean Delvare
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>
2009-09-18i2c: Convert i2c adapters to bus devicesJean Delvare
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>
2009-09-18i2c: Convert i2c clients to a device typeJean Delvare
This is required for upcoming changes. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Kay Sievers <kay.sievers@vrfy.org>
2009-06-19i2c: Use rwsem instead of mutex for board infoRodolfo Giometti
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>
2009-06-19i2c: Add a sysfs interface to instantiate devicesJean Delvare
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>
2009-06-19i2c: Limit core locking to the necessary sectionsJean Delvare
The i2c-core code tends to hold the core lock for longer than it should. Limit locking to the necessary sections for both performance and clarity. This is also a requirement to support I2C multiplexers in the future. Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Rodolfo Giometti <giometti@linux.it> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Kill the redundant client listJean Delvare
We used to maintain our own per-adapter list of i2c clients, but this is redundant with what the driver core does, and no longer needed. Just drop the redundant list. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Kill is_newstyle_driverJean Delvare
Legacy i2c drivers are gone, all drivers are new-style now, so there is no point to check. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Merge i2c_attach_client into i2c_new_deviceJean Delvare
Now that i2c_attach_client is no longer exported, it doesn't need to be a separate function. Merge it into its only user, i2c_new_device. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Drop i2c_probe functionJean Delvare
The legacy i2c_probe() function has no users left, get rid of it. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Get rid of the legacy binding modelJean Delvare
We converted all the legacy i2c drivers so we can finally get rid of the legacy binding model. Hooray! Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-19i2c: Kill client_register and client_unregister methodsJean Delvare
These methods were useful in the legacy binding model but no longer in the new (standard) binding model. There are no users left so we can drop them. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-06-15i2c: Do not give adapters a default parentJean Delvare
We don't need to give adapters a parent if they don't have one. The driver core will put them in the virtual device directory and all will be fine. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-15i2c: Retry automatically on arbitration lossClifford Wolf
Some small changes in i2c core to retry i2c xfers until either the maximum number of retries or the timeout is hit. Signed-off-by: Clifford Wolf <clifford@clifford.at> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-15i2c: Remove void castsJack Stone
Remove uneeded void casts. Signed-off-by: Jack Stone <jwjstone@fastmail.fm> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-04-13i2c: Let new-style drivers implement attach_adapterJean Delvare
While it isn't the way the standard device binding model works, it is OK for new-style drivers to implement attach_adapter. It may help convert the renaming legacy drivers to new style drivers faster. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <dbrownell@users.sourceforge.net>
2009-03-28i2c-core: Some style cleanupsZhenwen Xu
Some lines over 80. The printk(KERN_ERR ... ) should be dev_err. And some blankspace should be deleted. Signed-off-by: Zhenwen Xu <helight.xu@gmail.com> Signed-off-by: Jean Delvare <khlai@linux-fr.org>