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path: root/Documentation/i2c/writing-clients
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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>
2010-03-02i2c: 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>
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>
2009-06-19i2c: 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>
2009-03-28i2c: Document the different ways to instantiate i2c devicesJean Delvare
On popular demand, here comes some documentation about how to instantiate i2c devices in the new (standard) i2c device driver binding model. I have also clarified how the class bitfield lets driver authors control which buses are probed in the auto-detect case, and warned more loudly against the abuse of this method. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Michael Lawnick <nospam_lawnick@gmx.de> Acked-by: Hans Verkuil <hverkuil@xs4all.nl>
2008-10-22i2c: Update and clean up writing-clients documentJean Delvare
* Strip trailing white space. * Remove out-of-date or irrelevant parts. * Insist on the fact that command is deprecated. * Fix spelling mistakes and typos. * Reformat code examples and function prototypes to comply with the kernel coding style. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22i2c: Delete legacy model documentationJean Delvare
The legacy i2c binding model is deprecated and will be removed soon, so we no longer need to document it. 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>
2008-10-14i2c: Restore i2c_smbus_process_call functionPrakash Mortha
Restore the i2c_smbus_process_call() as one driver (for the Micronas MAP5401) will need it soon. [JD: Update documentation accordingly.] Signed-off-by: Prakash Mortha <pmortha@escient.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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: 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>
2008-07-14i2c-core: Return -Errno, not -1David Brownell
More updates to the I2C stack's fault reporting: make the core stop returning "-1" (usually "-EPERM") for all faults. Instead, pass lower level fault code up the stack, or return some appropriate errno. This patch happens to touch almost exclusively SMBus calls. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-01i2c: Documentation: fix device matching descriptionBen Dooks
The matching process described for new style clients in Documentation/i2c/writing-clients is classed as out-of-date as it requires the presence of an .id_table entry in the driver's i2c_driver entry. Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
2008-01-27i2c: normal_i2c can be made const (remaining drivers)Jean Delvare
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-07-12i2c: Fix the i2c_smbus_read_i2c_block_data() prototypeJean Delvare
Let the drivers specify how many bytes they want to read with i2c_smbus_read_i2c_block_data(). So far, the block count was hard-coded to I2C_SMBUS_BLOCK_MAX (32), which did not make much sense. Many driver authors complained about this before, and I believe it's about time to fix it. Right now, authors have to do technically stupid things, such as individual byte reads or full-fledged I2C messaging, to work around the problem. We do not want to encourage that. I even found that some bus drivers (e.g. i2c-amd8111) already implemented I2C block read the "right" way, that is, they didn't follow the old, broken standard. The fact that it was never noticed before just shows how little i2c_smbus_read_i2c_block_data() was used, which isn't that surprising given how broken its prototype was so far. There are some obvious compatiblity considerations: * This changes the i2c_smbus_read_i2c_block_data() prototype. Users outside the kernel tree will notice at compilation time, and will have to update their code. * User-space has access to i2c_smbus_xfer() directly using i2c-dev, so the changed expectations would affect tools such as i2cdump. In order to preserve binary compatibility, we give I2C_SMBUS_I2C_BLOCK_DATA a new numeric value, and define I2C_SMBUS_I2C_BLOCK_BROKEN with the old numeric value. When i2c-dev receives a transaction with the old value, it can convert it to the new format on the fly. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Documentation updateJean Delvare
Make the documentation on how to write and port i2c drivers more in line with the current state of things: * i2c-isa is deprecated and soon gone, so stop advertising it. * Drop many sensors-specific references. Most of them were outdated anyway. * Update the example code to reflect the recent and not-so-recent API and coding style preference changes. * Simplify the example init and cleanup functions. This should make things less complex to understand for newcomers. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Make i2c_del_driver a void functionJean Delvare
Make i2c_del_driver a void function, like all other driver removal functions. It always returned 0 even when errors occured, and nobody ever actually checked the return value anyway. And we cannot fail a module removal anyway. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: Document i2c_new_device()Jean Delvare
Document the new i2c_new_device(), i2c_new_probed_device() and i2c_unregister_device() functions. Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01i2c: i2c probe() and remove() documentedDavid Brownell
Update Documentation/i2c to match previous patches updating probe() and remove() logic. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-02-13i2c: Add driver suspend/resume/shutdown supportDavid Brownell
Driver model updates for the I2C core: - Add new suspend(), resume(), and shutdown() methods. Use them in the standard driver model style; document them. - Minor doc updates to highlight zero-initialized fields in drivers, and the driver model accessors for "clientdata". If any i2c drivers were previously using the old suspend/resume calls in "struct driver", they were getting warning messages ... and will now no longer work. Other than that, this patch changes no behaviors; and it lets I2C drivers use conventional PM and shutdown support. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Jean Delvare <khali@linux-fr.org>
2006-01-06[PATCH] i2c: update i2c_driver.command documentationJean Delvare
Document i2c_driver.command as being deprecated, and don't suggest an empty implementation of this callback as it doesn't make any sense. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-06[PATCH] i2c: Documentation updateJean Delvare
Update the i2c documentation to reflect the recent change to i2c_add_driver. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-06[PATCH] i2c: Drop i2c_driver.{owner,name}, 11 of 11Jean Delvare
Document the drop of the owner and name fields of the i2c_driver structure. Signed-off-by: Jean Delvare <khali@linux-fr.org> CC: Laurent Riffard <laurent.riffard@free.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2006-01-06[PATCH] i2c: Drop i2c_driver.flags, 2 of 3Jean Delvare
Just about every i2c chip driver sets the I2C_DF_NOTIFY flag, so we can simply make it the default and drop the flag. If any driver really doesn't want to be notified when i2c adapters are added, that driver can simply omit to set .attach_adapter. This approach is also more robust as it prevents accidental NULL pointer dereferences. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-08[PATCH] i2c: writing-client doc update complementJean Delvare
My latest update to the writing-clients i2c documentation file was incomplete, here's the complement. Large parts of this file are still way out-of-date, but at least now the memory allocation and freeing instructions are consistent. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-31[PATCH] remove some more check_region stuffJeff Garzik
Removed some more references to check_region(). I checked these changes into the 'checkreg' branch of rsync://rsync.kernel.org/pub/scm/linux/kernel/git/jgarzik/misc-2.6.git The only valid references remaining are in: drivers/scsi/advansys.c drivers/scsi/BusLogic.c drivers/cdrom/sbpcd.c sound/oss/pss.c Remove last vestiges of ide_check_region() drivers/char/specialix: trim trailing whitespace drivers/char/specialix: eliminate use of check_region() Remove outdated and unused references to check_region() [sound oss] remove check_region() usage from cs4232, wavfront [netdrvr eepro] trim trailing whitespace [netdrvr eepro] remove check_region() usage Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-28[PATCH] i2c: Documentation updateJean Delvare
Update the i2c documentation: kzalloc should be used instead of kmalloc. I also fixed a couple other things nearby in writing-clients, as several past changes had never been reported there. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-10-28[PATCH] i2c: Documentation fixesJean Delvare
i2c documentation fixes. >From Hideki Iwamoto: * i2c_smbus_read_i2c_block_data is not deleted in 2.6.10. It still exists. * The name which can be set to i2c_driver is up to 31 characters. >From Jean Delvare: * Reword the paragraph about i2c_driver.name, to reflect the "new" naming policy. * Delete the out-of-date note about now gone inc_use and dec_use fields. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] I2C: Rewrite i2c_probeJean Delvare
i2c_probe was quite complex and slow, so I rewrote it in a more efficient and hopefully clearer way. Note that this slightly changes the way the module parameters are handled. This shouldn't change anything for the most common cases though. For one thing, the function now respects the order of the parameters for address probing. It used to always do lower addresses first. The new approach gives the user more control. For another, ignore addresses don't overrule probe addresses anymore. This could have been restored the way it was at the cost of a few more lines of code, but I don't think it's worth it. Both lists are given as module parameters, so a user would be quite silly to specify the same addresses in both lists. The normal addresses list is the only one that isn't controlled by a module parameter, thus is the only one the user may reasonably want to remove an address from. Another significant change is the fact that i2c_probe() will no more stop when a detection function returns -ENODEV. Just because a driver found a chip it doesn't support isn't a valid reason to stop all probings for this one driver. This closes the long standing lm_sensors ticket #1807. http://www2.lm-sensors.nu/~lm78/readticket.cgi?ticket=1807 I updated the documentation accordingly. In terms of algorithmic complexity, the new code is way better. If I is the ignore address count, P the probe address count, N the normal address count and F the force address count, the old code was doing 128 * (F + I + P + N) iterations max, while the new code does F + P + ((I+1) * N) iterations max. For the most common case where F, I and P are empty, this is down from 128 * N to N. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] hwmon: hwmon vs i2c, second round (06/11)Jean Delvare
The only thing left in i2c-sensor.h are module parameter definition macros. It's only an extension of what i2c.h offers, and this extension is not sensors-specific. As a matter of fact, a few non-sensors drivers use them. So we better merge them in i2c.h, and get rid of i2c-sensor.h altogether. Signed-off-by: Jean Delvare <khali@linux-fr> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] hwmon: hwmon vs i2c, second round (04/11)Jean Delvare
i2c_probe and i2c_detect now do the exact same thing and operate on the same data structure, so we can have everyone call i2c_probe. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] I2C: refactor message in i2c_detach_clientJean Delvare
We could refactor the error message 34 different i2c drivers print if i2c_detach_client() fails in this function itself. Saves quite a few lines of code. Documentation is updated to reflect that change. Note that this patch should be applied after Rudolf Marek's w83792d patches. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] I2C: Separate non-i2c hwmon drivers from i2c-core (8/9)Jean Delvare
Kill all uses of i2c_is_isa_adapter except for the hybrid drivers (it87, lm78, w83781d). The i2c-isa adapter not being registered with the i2c core anymore, drivers don't have to fear being erroneously attached to it. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-09-05[PATCH] I2C: Separate non-i2c hwmon drivers from i2c-core (7/9)Jean Delvare
Kill normal_isa in header files, documentation and all chip drivers, as it is no more used. normal_i2c could be renamed to normal, but I decided not to do so at the moment, so as to limit the number of changes. This might be done later as part of the i2c_probe/i2c_detect merge. Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-07-11[PATCH] I2C: minor I2C doc cleanupsdavid-b@pacbell.net
The I2C stack has long had "id" fields, of rather dubious utility, in many data structures. This removes mention of one of them from the documentation about how to write an I2C driver, so that only drivers that really need to use them (probably old/legacy code) will have any reason to use this field. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-06-22[PATCH] I2C: Kill address ranges in non-sensors i2c chip driversJean Delvare
Some months ago, you killed the address ranges mechanism from all sensors i2c chip drivers (both the module parameters and the in-code address lists). I think it was a very good move, as the ranges can easily be replaced by individual addresses, and this allowed for significant cleanups in the i2c core (let alone the impressive size shrink for all these drivers). Unfortunately you did not do the same for non-sensors i2c chip drivers. These need the address ranges even less, so we could get rid of the ranges here as well for another significant i2c core cleanup. Here comes a patch which does just that. Since the process is exactly the same as what you did for the other drivers set already, I did not split this one in parts. A documentation update is included. The change saves 308 bytes in the i2c core, and an average 1382 bytes for chip drivers which use I2C_CLIENT_INSMOD, 126 bytes for those which do not. This change is required if we want to merge the sensors and non-sensors i2c code (and we want to do this). Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Index: gregkh-2.6/Documentation/i2c/writing-clients ===================================================================
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!