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path: root/include/linux/i2c.h
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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: Add SMBus alert supportJean Delvare
SMBus alert support. The SMBus alert protocol allows several SMBus slave devices to share a single interrupt pin on the SMBus master, while still allowing the master to know which slave triggered the interrupt. This is based on preliminary work by David Brownell. The key difference between David's implementation and mine is that his was part of i2c-core, while mine is split into a separate, standalone module named i2c-smbus. The i2c-smbus module is meant to include support for all SMBus extensions to the I2C protocol in the future. The benefit of this approach is a zero cost for I2C bus segments which do not need SMBus alert support. Where David's implementation increased the size of struct i2c_adapter by 7% (40 bytes on i386), mine doesn't touch it. Where David's implementation added over 150 lines of code to i2c-core (+10%), mine doesn't touch it. The only change that touches all the users of the i2c subsystem is a new callback in struct i2c_driver (common to both implementations.) I seem to remember Trent was worried about the footprint of David'd implementation, hopefully mine addresses the issue. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: David Brownell <dbrownell@users.sourceforge.net> Cc: Trent Piepho <tpiepho@freescale.com>
2009-12-14i2c: Get rid of I2C_CLIENT_MODULE_PARMJean Delvare
There is no user left of I2C_CLIENT_MODULE_PARM, so we can finally get rid of this ugly macro. Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-12-14i2c: Drop I2C_CLIENT_INSMOD_2 to 8Jean Delvare
These macros simply declare an enum, so drivers might as well declare it themselves. This puts an end to the arbitrary limit of 8 chip types per i2c driver. Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Wolfram Sang <w.sang@pengutronix.de>
2009-12-14i2c: Drop I2C_CLIENT_INSMOD_1Jean Delvare
This macro simply declares an enum, so drivers might as well declare it themselves. Signed-off-by: Jean Delvare <khali@linux-fr.org> Tested-by: Wolfram Sang <w.sang@pengutronix.de>
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: 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>
2009-11-07i2c: Add an interface to lock/unlock an I2C bus segmentJean Delvare
Some drivers need to be able to prevent access to an I2C bus segment for a specific period of time. Add an interface for them to do so without twiddling with i2c-core internals. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Ben Hutchings <bhutchings@solarflare.com>
2009-09-18i2c: Drop unused i2c_driver.id fieldJean Delvare
Nobody is using i2c_driver.id any longer, so we can drop that field. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-19i2c: New macro to initialize i2c address lists on the flyHans Verkuil
For video4linux we sometimes need to probe for a single i2c address. Normally you would do it like this: static const unsigned short addrs[] = { addr, I2C_CLIENT_END }; client = i2c_new_probed_device(adapter, &info, addrs); This is a bit awkward and I came up with this macro: #define V4L2_I2C_ADDRS(addr, addrs...) \ ((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END }) This can construct a list of one or more i2c addresses on the fly. But this is something that really belongs in i2c.h, renamed to I2C_ADDRS. With this macro we can just do: client = i2c_new_probed_device(adapter, &info, I2C_ADDRS(addr)); Note that this can also be used to initialize an array: static const unsigned short addrs[] = I2C_ADDRS(0x2a, 0x2c); Whether you want to is another matter, but it works. This functionality is also available in the oldest supported gcc (3.2). Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-06-19i2c: Don't advertise i2c functions when not availableJean Delvare
Surround i2c function declarations with ifdefs, so that they aren't advertised when i2c-core isn't actually built. That way, drivers using these functions unconditionally will result in an immediate build failure, rather than a late linking failure which is harder to figure out. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Paul Mundt <lethal@linux-sh.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: 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: 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>
2009-04-13i2c: Fix sparse warnings for I2C_BOARD_INFO()Ben Hutchings
Since the first argument to I2C_BOARD_INFO() must be a string constant, there is no need to parenthesise it, and adding parentheses results in an invalid initialiser for char[]. gcc obviously accepts this syntax as an extension, but sparse complains, e.g.: drivers/net/sfc/boards.c:173:2: warning: array initialized from parenthesized string constant Therefore, remove the parentheses. Signed-off-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-04-06i2c: Deprecate client_register and client_unregister methodsJean Delvare
The new i2c binding model makes the client_register and client_unregister methods of struct i2c_adapter useless, so we can remove them with the rest of the legacy model. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-02-24i2c-dev: Clarify the unit of ioctl I2C_TIMEOUTJean Delvare
The unit in which user-space can set the bus timeout value is jiffies for historical reasons (back when HZ was always 100.) This is however not good because user-space doesn't know how long a jiffy lasts. The timeout value should instead be set in a fixed time unit. Given the original value of HZ, this unit should be 10 ms, for compatibility. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Wolfram Sang <w.sang@pengutronix.de>
2009-01-26i2c: Warn on deprecated binding model useJean Delvare
Let the kernel developers know that i2c_attach_client() and i2c_detach_client() are deprecated and should no longer be used. Drivers using these should be converted to the standard device driver binding model (probe and remove methods.) Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Ben Dooks <ben-linux@fluff.org>
2009-01-07i2c: Drop I2C_CLASS_CAM_DIGITALJean Delvare
There are a number of drivers which set their i2c bus class to I2C_CLASS_CAM_DIGITAL, however no chip driver actually checks for this flag, so we might as well drop it now. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-01-07i2c: Drop I2C_CLASS_CAM_ANALOG and I2C_CLASS_SOUNDJean Delvare
There are no users left of these two i2c probe class flags so we can drop the now. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-01-07i2c: Drop I2C_CLASS_ALLJean Delvare
I2C_CLASS_ALL is almost never what bus driver authors really want. These i2c classes are really only about which devices must be probed, not what devices can be present. As device drivers get converted to the new i2c device driver model, only a few device types will keep relying on probing. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Sonic Zhang <sonic.zhang@analog.com>
2008-10-22i2c: Add info->archdata fieldAnton Vorontsov
If present the info->archdata is copied into the dev->archdata. Some (OpenFirmware) platforms need it. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22i2c: Clean up <linux/i2c.h>Jean Delvare
Fix most checkpatch.pl errors and warnings. This includes replacing spaces with tabs in many places, adding and removing spaces, and folding long lines. Also complete a couple prototypes to make it clearer what the parameters represent. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22i2c: Drop 2-byte address block transfer definesJean Delvare
We have no users and no implementers for these transfer types so it makes little sense to define functionality bits for them. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22i2c: Constify i2c_get_clientdata's parameterJean Delvare
i2c_get_clientdata doesn't change the i2c_client it is passed as a parameter, so it can be constified. Same for i2c_get_adapdata. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22i2c: Make clear what the class field of i2c_adapter is good forWolfram Sang
Make clear what the class field of i2c_adapter is good for. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-08-28i2c: Add missing kerneldoc descriptionsJean Delvare
Add missing kernel descriptions of struct i2c_driver members. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Cc: David Brownell <david-b@pacbell.net>
2008-07-14i2c: Add detection capability to new-style driversJean Delvare
Add a mechanism to let new-style i2c drivers optionally autodetect devices they would support on selected buses and ask i2c-core to instantiate them. This is a replacement for legacy i2c drivers, much cleaner. Where drivers had to implement both a legacy i2c_driver and a new-style i2c_driver so far, this mechanism makes it possible to get rid of the legacy i2c_driver and implement both enumerated and detected device support with just one (new-style) i2c_driver. Here is a quick conversion guide for these drivers, step by step: * Delete the legacy driver definition, registration and removal. Delete the attach_adapter and detach_client methods of the legacy driver. * Change the prototype of the legacy detect function from static int foo_detect(struct i2c_adapter *adapter, int address, int kind); to static int foo_detect(struct i2c_client *client, int kind, struct i2c_board_info *info); * Set the new-style driver detect callback to this new function, and set its address_data to &addr_data (addr_data is generally provided by I2C_CLIENT_INSMOD.) * Add the appropriate class to the new-style driver. This is typically the class the legacy attach_adapter method was checking for. Class checking is now mandatory (done by i2c-core.) See <linux/i2c.h> for the list of available classes. * Remove the i2c_client allocation and freeing from the detect function. A pre-allocated client is now handed to you by i2c-core, and is freed automatically. * Make the detect function fill the type field of the i2c_board_info structure it was passed as a parameter, and return 0, on success. If the detection fails, return -ENODEV. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14i2c: Export the i2c_bus_type symbolJon Smirl
Export the root of the i2c bus so that PowerPC device tree code can iterate over devices on the i2c bus. Signed-off-by: Jon Smirl <jonsmirl@gmail.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14i2c: Let bus drivers add SPD to their classJean Delvare
Let general purpose I2C/SMBus bus drivers add SPD to their class. Once this is done, we will be able to tell the eeprom driver to only probe for SPD EEPROMs and similar on these buses. Note that I took a conservative approach here, adding I2C_CLASS_SPD to many drivers that have no idea whether they can host SPD EEPROMs or not. This is to make sure that the eeprom driver doesn't stop probing buses where SPD EEPROMs or equivalent live. So, bus driver maintainers and users should feel free to remove the SPD class from drivers those buses never have SPD EEPROMs or they don't want the eeprom driver to bind to them. Likewise, feel free to add the SPD class to any bus driver I might have missed. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14i2c: Let framebuffer drivers set their I2C bus class to DDCJean Delvare
Let framebuffer drivers set their I2C bus class to DDC. Once this is done, we will be able to tell the eeprom driver to only probe for EDID EEPROMs on these buses. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14i2c: Update stray references to smbus_accessJean Delvare
That function is actually named i2c_smbus_xfer. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14i2c: Delete unused function i2c_smbus_write_quickJean Delvare
Function i2c_smbus_write_quick has no users left, so we can delete it. Also update the list of these helper functions which are gone but could be added back if needed. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-01i2c: Fix bad hint about irqs in i2c.hWolfram Sang
i2c.h mentions -1 as a not-issued irq. This false hint was taken by of_i2c and caused crashes. Don't give any advice as 'no irq' is not consistent across all architectures yet and it is not needed internally by the i2c-core. Signed-off-by: Wolfram Sang <w.sang@pengutronix.de> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-05-18i2c: Kill the old driver matching schemeJean Delvare
Remove the old driver_name/type scheme for i2c driver matching. Only the standard aliasing model will be used from now on. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-05-11i2c: Match dummy devices by typeJean Delvare
As the old driver_name/type matching scheme is going away soon, change the dummy device mechanism to use the new matching scheme. This has the downside that dummy i2c clients can no longer choose their name, they'll all appear as "dummy" in sysfs and in log messages. I don't think it is a problem in practice though, as there is little reason to use these i2c clients to log messages. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-04-29i2c: Convert most new-style drivers to use module aliasingJean Delvare
Based on earlier work by Jon Smirl and Jochen Friedrich. Update most new-style i2c drivers to use standard module aliasing instead of the old driver_name/type driver matching scheme. I've left the video drivers apart (except for SoC camera drivers) as they're a bit more diffcult to deal with, they'll have their own patch later. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Jon Smirl <jonsmirl@gmail.com> Cc: Jochen Friedrich <jochen@scram.de>
2008-04-29i2c: Add support for device alias namesJean Delvare
Based on earlier work by Jon Smirl and Jochen Friedrich. This patch allows new-style i2c chip drivers to have alias names using the official kernel aliasing system and MODULE_DEVICE_TABLE(). At this point, the old i2c driver binding scheme (driver_name/type) is still supported. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Jochen Friedrich <jochen@scram.de> Cc: Jon Smirl <jonsmirl@gmail.com> Cc: Kay Sievers <kay.sievers@vrfy.org>
2008-02-24i2c: Make i2c_register_board_info() a NOP when CONFIG_I2C_BOARDINFO=nDavid Brownell
Don't require platform code to be #ifdeffed according to whether I2C is enabled or not ... if it's not enabled, let GCC compile out all I2C device declarations. (Issue noted on an NSLU2 build that didn't configure I2C.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-02-24i2c: 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>
2008-01-27i2c: Add i2c_new_dummy() utilityDavid Brownell
This adds a i2c_new_dummy() primitive to help work with devices that consume multiple addresses, which include many I2C eeproms and at least one RTC. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27i2c: Stop using the redundant client listDavid Brownell
The i2c_adapter.clients list of i2c_client nodes duplicates driver model state. This patch starts removing that list, letting us remove most existing users of those i2c-core lists. * The core I2C code now iterates over the driver model's list instead of the i2c-internal one in some places where it's safe: - Passing a command/ioctl to each client, a mechanims used almost exclusively by DVB adapters; - Device address checking, in both i2c-core and i2c-dev. * Provide i2c_verify_client() to use with driver model iterators. * Flag the relevant i2c_adapter and i2c_client fields as deprecated, to help prevent new users from appearing. For the moment the list needs to stick around, since some issues show up when deleting devices created by legacy I2C drivers. (They don't follow standard driver model rules. Removing those devices can cause self-deadlocks.) Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27i2c: Drop redundant i2c_driver.listJean Delvare
i2c_driver.list is superfluous, this list duplicates the one maintained by the driver core. Drop it. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net>
2008-01-27i2c: Drop redundant i2c_adapter.listJean Delvare
i2c_adapter.list is superfluous, this list duplicates the one maintained by the driver core. Drop it. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: David Brownell <dbrownell@users.sourceforge.net>
2008-01-27i2c: Change prototypes of refcounting functionsJean Delvare
Use more standard prototypes for i2c_use_client() and i2c_release_client(). The former now returns a pointer to the client, and the latter no longer returns anything. This matches what all other subsystems do. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: David Brownell <david-b@pacbell.net>