Commit Graph

101 Commits

Author SHA1 Message Date
Jean Delvare
cd97f39b7c i2c-dev: Clarify the unit of ioctl I2C_TIMEOUT
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>
2009-02-24 19:19:49 +01:00
Jean Delvare
5fb4523afb i2c: Warn on deprecated binding model use
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>
2009-01-26 21:19:57 +01:00
Jean Delvare
b305271861 i2c: Drop I2C_CLASS_CAM_DIGITAL
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>
2009-01-07 14:29:17 +01:00
Jean Delvare
994a075f0f i2c: Drop I2C_CLASS_CAM_ANALOG and I2C_CLASS_SOUND
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>
2009-01-07 14:29:17 +01:00
Jean Delvare
e1995f65be i2c: Drop I2C_CLASS_ALL
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>
2009-01-07 14:29:16 +01:00
Anton Vorontsov
11f1f2afd6 i2c: Add info->archdata field
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>
2008-10-22 20:21:33 +02:00
Jean Delvare
3ae70deef0 i2c: Clean up <linux/i2c.h>
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>
2008-10-22 20:21:32 +02:00
Jean Delvare
c0589d4bc1 i2c: Drop 2-byte address block transfer defines
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>
2008-10-22 20:21:31 +02:00
Jean Delvare
7d1d8999b4 i2c: Constify i2c_get_clientdata's parameter
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>
2008-10-22 20:21:31 +02:00
Wolfram Sang
14f55f7a03 i2c: Make clear what the class field of i2c_adapter is good for
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>
2008-10-22 20:21:30 +02:00
Jean Delvare
96e21e4fbc i2c: Add missing kerneldoc descriptions
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>
2008-08-28 08:33:23 +02:00
Jean Delvare
4735c98f84 i2c: Add detection capability to new-style drivers
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>
2008-07-14 22:38:36 +02:00
Jon Smirl
e9ca9eb9d7 i2c: Export the i2c_bus_type symbol
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>
2008-07-14 22:38:35 +02:00
Jean Delvare
3401b2fff3 i2c: Let bus drivers add SPD to their class
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>
2008-07-14 22:38:29 +02:00
Jean Delvare
c1b6b4f234 i2c: Let framebuffer drivers set their I2C bus class to DDC
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>
2008-07-14 22:38:28 +02:00
Jean Delvare
ae7193f7fa i2c: Update stray references to smbus_access
That function is actually named i2c_smbus_xfer.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-14 22:38:24 +02:00
Jean Delvare
67c2e66571 i2c: Delete unused function i2c_smbus_write_quick
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>
2008-07-14 22:38:23 +02:00
Wolfram Sang
8e29da9ee8 i2c: Fix bad hint about irqs in i2c.h
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>
2008-07-01 22:38:18 +02:00
Jean Delvare
eb8a790809 i2c: Kill the old driver matching scheme
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>
2008-05-18 20:49:41 +02:00
Jean Delvare
60b129d7bf i2c: Match dummy devices by type
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>
2008-05-11 20:37:06 +02:00
Jean Delvare
3760f73671 i2c: Convert most new-style drivers to use module aliasing
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>
2008-04-29 23:11:40 +02:00
Jean Delvare
d2653e9273 i2c: Add support for device alias names
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>
2008-04-29 23:11:39 +02:00
David Brownell
263867631e i2c: Make i2c_register_board_info() a NOP when CONFIG_I2C_BOARDINFO=n
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>
2008-02-24 20:03:42 +01:00
Tobias Klauser
305183fc3e i2c: 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>
2008-02-24 20:03:42 +01:00
David Brownell
e9f1373b64 i2c: Add i2c_new_dummy() utility
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>
2008-01-27 18:14:52 +01:00
David Brownell
9b766b814d i2c: Stop using the redundant client list
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>
2008-01-27 18:14:51 +01:00
Jean Delvare
026526f5af i2c: Drop redundant i2c_driver.list
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>
2008-01-27 18:14:49 +01:00
Jean Delvare
87c6c22945 i2c: Drop redundant i2c_adapter.list
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>
2008-01-27 18:14:48 +01:00
Jean Delvare
e48d33193d i2c: Change prototypes of refcounting functions
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>
2008-01-27 18:14:48 +01:00
Jean Delvare
bdc511f438 i2c: Use the driver model reference counting
Don't implement our own reference counting mechanism for i2c clients
when the driver model already has one.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
2008-01-27 18:14:48 +01:00
Mark M. Hoffman
bfb6df24fa i2c: Constify client address data
This patch allows much of the I2C client address data to move from initdata
into text.
    
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-01-27 18:14:46 +01:00
Jean Delvare
5e31c2bd3c i2c: Make i2c_check_addr static
i2c_check_addr is only used inside i2c-core now, so we can make it
static and stop exporting it. Thanks to David Brownell for noticing.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-11-15 19:24:02 +01:00
David Brownell
6662cbb989 i2c: Rename the PEC functionality bit
Rename I2C_FUNC_SMBUS_HWPEC_CALC as I2C_FUNC_SMBUS_PEC, and list that
functionality as always available through the software implementation.
Update documentation accordingly (and list similar requirements).

The way it's currently packaged doesn't present the capability in a
useful way.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:33 +02:00
David Brownell
08fb68bb4b i2c: Move i2c-dev interfaces to i2c-dev.h
Move the i2c-dev support into <linux/i2c-dev.h> where it should always
have lived.  Now <linux/i2c.h> no longer holds stuff related to the
optional userspace /dev/i2c-X interface.  Improve the descriptions
for these ioctl requests.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:32 +02:00
David Brownell
53be795934 i2c: Remove i2c_algorithm.algo_control()
This removes:

 - An effectively unused hook:  i2c_algorithm.algo_control.

 - The i2c_control() call, used only by i2c-dev to call that
   unused hook or set two barely supported adapter params.

   (That param setting moves into i2c-dev.c ... still iffy
   due to lack of locking, but no other changes.)

As shown by diffstat, this is a net code shrink.  It also reduces the
complexity of the I2C adapter and /dev interfaces.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:32 +02:00
David Brownell
a64ec07d3d i2c: Document struct i2c_msg
Clarify use of the I2C_M_* flags by highlighting the fact that
most of them depend on I2C_FUNC_PROTOCOL_MANGLING.

Also provide kerneldoc for i2c_smbus_read_block_data() and also
for "struct i2c_msg".

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:31 +02:00
Adrian Bunk
83eaaed0d0 i2c-core: Make some code static
After the i2c-isa removal some code can become static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:30 +02:00
David Brownell
3bbb835d4c i2c: New-style devices can support driver model wakeup flags
We need to be able to flag I2C devices, such as RTCs, which can issue wake
events (usually through IRQ lines).  This adds an i2c_board_info.flags bit,
and uses it to initialize the i2c device node.  (And shrinks a few lines
that were overly long.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-10-13 23:56:29 +02:00
Randy Dunlap
aa3481d5e6 i2c.h kernel-doc additions
Add kernel-doc notation in <linux/i2c.h> for:

Warning(linux-2.6.22-git12//include/linux/i2c.h:183): No description found for parameter 'driver'
Warning(linux-2.6.22-git12//include/linux/i2c.h:183): No description found for parameter 'usage_count'
Warning(linux-2.6.22-git12//include/linux/i2c.h:183): No description found for parameter 'list'
Warning(linux-2.6.22-git12//include/linux/i2c.h:183): No description found for parameter 'released'

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-31 15:39:41 -07:00
Linus Torvalds
40b42f1ebf Merge branch 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6
* 'release' of git://lm-sensors.org/kernel/mhoffman/hwmon-2.6: (44 commits)
  i2c: Delete the i2c-isa pseudo bus driver
  hwmon: refuse to load abituguru driver on non-Abit boards
  hwmon: fix Abit Uguru3 driver detection on some motherboards
  hwmon/w83627ehf: Be quiet when no chip is found
  hwmon/w83627ehf: No need to initialize fan_min
  hwmon/w83627ehf: Export the thermal sensor types
  hwmon/w83627ehf: Enable VBAT monitoring
  hwmon/w83627ehf: Add support for the VID inputs
  hwmon/w83627ehf: Fix timing issues
  hwmon/w83627ehf: Add error messages for two error cases
  hwmon/w83627ehf: Convert to a platform driver
  hwmon/w83627ehf: Update the Kconfig entry
  make coretemp_device_remove() static
  hwmon: Add LM93 support
  hwmon: Improve the pwmN_enable documentation
  hwmon/smsc47b397: Don't report missing fans as spinning at 82 RPM
  hwmon: Add support for newer uGuru's
  hwmon/f71805f: Add temperature-tracking fan control mode
  hwmon/w83627ehf: Preserve speed reading when changing fan min
  hwmon: fix detection of abituguru volt inputs
  ...

Manual fixup of trivial conflict in MAINTAINERS file
2007-07-19 14:24:57 -07:00
Jean Delvare
e24b8cb4fa i2c: Delete the i2c-isa pseudo bus driver
There are no users of i2c-isa left, so we can finally get rid of it.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-07-19 14:25:20 -04:00
Jean Delvare
4b2643d7d9 i2c: Fix the i2c_smbus_read_i2c_block_data() prototype
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>
2007-07-12 14:12:29 +02:00
Mark M. Hoffman
d75d53cd57 i2c: Fix sparse warning in i2c.h
Kill a sparse warning by un-nesting two container_of() calls.
    
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-07-12 14:12:28 +02:00
David Brownell
d64f73be1b i2c: Add kernel documentation
Generate I2C kerneldoc; fix various glitches and add "context" sections to
that documentation.  Most I2C and SMBus functions still have no kerneldoc.

Let me suggest providing kerneldoc for all the i2c_smbus_*() functions as
a small and mostly self-contained project for anyone so inclined.  :)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-07-12 14:12:28 +02:00
Jean Delvare
b86a1bc8e3 i2c: Restore i2c_smbus_read_block_data
Add back the i2c_smbus_read_block_data helper function, it is needed
by the upcoming lm93 hardware monitoring driver and possibly others.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:34 +02:00
Jean Delvare
b3e820968a i2c: Make i2c_del_driver a void function
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>
2007-05-01 23:26:32 +02:00
Jean Delvare
a97f1ed090 i2c: Move i2c-isa-only exported symbol declarations
Move the declaration of i2c-isa-only exported symbols to i2c-isa
itself, that's the best way to ensure nobody will attempt to use them.
Hopefully we'll get rid of the exports themselves soon anyway.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:32 +02:00
Jean Delvare
12b5053ac5 i2c: Add i2c_new_probed_device()
Add a new helper function to instantiate an i2c device. It is meant as a
replacement for i2c_new_device() when you don't know for sure at which
address your I2C/SMBus device lives. This happens frequently on TV
adapters for example, you know there is a tuner chip on the bus, but
depending on the exact board model and revision, it can live at different
addresses. So, the new i2c_new_probed_device() function will probe the bus
according to a list of addresses, and as soon as one of these addresses
responds, it will call i2c_new_device() on that one address.

This function will make it possible to port the old i2c drivers to the
new model quickly.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:31 +02:00
David Brownell
6e13e64184 i2c: Add i2c_add_numbered_adapter()
This adds a call, i2c_add_numbered_adapter(), registering an I2C adapter
with a specific bus number and then creating I2C device nodes for any
pre-declared devices on that bus.  It builds on previous patches adding
I2C probe() and remove() support, and that pre-declaration of devices.

This completes the core support for "new style" I2C device drivers.
Those follow the standard driver model for binding devices to drivers
(using probe and remove methods) rather than a legacy model (where the
driver tries to autoconfigure each bus, and registers devices itself).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:31 +02:00
David Brownell
9c1600eda4 i2c: Add i2c_board_info and i2c_new_device()
This provides partial support for new-style I2C driver binding.  It builds
on "struct i2c_board_info" declarations that identify I2C devices on a given
board.  This is needed on systems with I2C devices that can't be fully probed
and/or autoconfigured, such as many embedded Linux configurations where the
way a given I2C device is wired may affect how it must be used.

There are two models for declaring such devices:

 * LATE -- using a public function i2c_new_device().  This lets modules
   declare I2C devices found *AFTER* a given I2C adapter becomes available.
   
   For example, a PCI card could create adapters giving access to utility
   chips on that card, and this would be used to associate those chips with
   those adapters.

 * EARLY -- from arch_initcall() level code, using a non-exported function
   i2c_register_board_info().  This copies the declarations *BEFORE* such
   an i2c_adapter becomes available, arranging that i2c_new_device() will
   be called later when i2c-core registers the relevant i2c_adapter.

   For example, arch/.../.../board-*.c files would declare the I2C devices
   along with their platform data, and I2C devices would behave much like
   PNPACPI devices.  (That is, both enumerate from board-specific tables.)

To match the exported i2c_new_device(), the previously-private function
i2c_unregister_device() is now exported.

Pending later patches using these new APIs, this is effectively a NOP.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2007-05-01 23:26:31 +02:00