Commit Graph

113 Commits

Author SHA1 Message Date
Jean Delvare afa08974fe i2c: Add an interface to lock/unlock an I2C bus segment
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>
2009-11-07 13:10:46 +01:00
Jean Delvare 6a891a3111 i2c: Drop unused i2c_driver.id field
Nobody is using i2c_driver.id any longer, so we can drop that field.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-09-18 22:45:43 +02:00
Hans Verkuil c70366732f i2c: New macro to initialize i2c address lists on the fly
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>
2009-06-19 16:58:21 +02:00
Jean Delvare 23af840057 i2c: Don't advertise i2c functions when not available
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>
2009-06-19 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
Jean Delvare e549c2b54d i2c: Kill the redundant client list
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>
2009-06-19 16:58:19 +02:00
Jean Delvare 1e40ac12da i2c: Kill is_newstyle_driver
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>
2009-06-19 16:58:19 +02:00
Jean Delvare 36789b5ea5 i2c: Drop i2c_probe function
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>
2009-06-19 16:58:18 +02:00
Jean Delvare 729d6dd571 i2c: Get rid of the legacy binding model
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>
2009-06-19 16:58:18 +02:00
Jean Delvare 352da9820e i2c: Kill client_register and client_unregister methods
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>
2009-06-19 16:58:17 +02:00
Ben Hutchings c758e8cffe i2c: Fix sparse warnings for I2C_BOARD_INFO()
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>
2009-04-13 17:02:14 +02:00
Jean Delvare e3ee703366 i2c: Deprecate client_register and client_unregister methods
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>
2009-04-06 18:12:24 +02:00
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