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>
Make i2c-core.c obey Documentation/CodingStyle better by snugging
the EXPORT_SYMBOL declarations next to the relevant definitions.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
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>
More update for new style driver support: add a remove() method, and
use it in the relevant code paths.
Again, nothing will use this yet since there's nothing to create devices
feeding this infrastructure.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
One of a series of I2C infrastructure updates to support enumeration using
the standard Linux driver model.
This patch updates probe() and associated hotplug/coldplug support, but
not remove(). Nothing yet _uses_ it to create I2C devices, so those
hotplug/coldplug mechanisms will be the only externally visible change.
This patch will be an overall NOP since the I2C stack doesn't yet create
clients/devices except as part of binding them to legacy drivers.
Some code is moved earlier in the source code, helping group more of the
per-device infrastructure in one place and simplifying handling per-device
attributes.
Terminology being adopted: "legacy drivers" create devices (i2c_client)
themselves, while "new style" ones follow the driver model (the i2c_client
is handed to the probe routine). It's an either/or thing; the two models
don't mix, and drivers that try mixing them won't even be registered.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Let the I2C bus drivers emulate the SMBus Block Read and Block Process
Call transactions if they wish. This requires to define a new message
flag, which i2c-core will use to let the underlying I2C bus driver
know that the first received byte will specify the length of the read
message.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Rename dev_to_i2c_adapter() as to_i2c_adapter(), since the previous
syntax was a surprising and needless difference from normal naming
conventions in Linux.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patch is a minor cleanup/code shrink, using class infrastructure
in i2c-core to manage the i2c_adapter attribute.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Kill i2c_adapter_driver as it doesn't make sense and it prevents
further i2c-core cleanups. i2c_adapter devices are virtual devices
(ex-class devices) and as such they don't need a driver.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Kill i2c_adapter.class_dev. Instead, set the class of i2c_adapter.dev
to i2c_adapter_class, so that a symlink will be created for every
i2c_adapter in /sys/class/i2c-adapter.
The same change must be mirrored to i2c-isa as it duplicates some
of the i2c-core functionalities.
User-space tools and libraries might need some adjustments. In
particular, libsensors from lm_sensors 2.10.3 or later is required for
proper discovery of i2c adapter names after this change.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Now that the i2c_adapter migration plan changed and we are going to
keep i2c_adapter.dev, it's no longer that urgent to add a proper device
to all i2c_adapter drivers. Thus is seems resonable to degrade the
warning asking authors to migrate their driver to a debug message.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
i2c-core and i2c-isa use completions without including
<linux/completion.h>. Fix it.
i2c-powermac includes <linux/completion.h> but doesn't use any
completion. Fix it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Flag i2c_adapter.dev for removal after userspace tools get upgraded, and
include a near-term code migration aid to facilitate this:
- The class device gets the name attribute it should have had. This
was previously (wrongly) associated with the i2c_adapter.dev node.
Sysfs based tools and libraries can start converting right away.
- Issue a warning for legacy adapter drivers that don't provide any
physical device node; so systems with those drivers will know to
fix this problem earlier.
This is one of a series of patches to help the I2C stack become a better
citizen of the Linux Driver Model world.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Remove extraneous whitespace from various i2c headers and core files,
like space-before-tab and whitespace at end of line.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This patch adds the 'level' field into the i2c_adapter structure, which is
used to represent the 'logical' level of nesting for the purposes of
lockdep. This field is then used in the i2c_transfer() function, to
acquire the per-adapter bus_lock with correct nesting level.
Signed-off-by: Jiri Kosina <jikos@jikos.cz>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Delay the call to adapter->client_register() until after we are
certain that the client registration is a success. At this point the
client is fully initialized and we no longer hold the adapter->clist
mutex, so this should prevent the deadlocks if the client_register()
callback needs to take that mutex too, as is the case for the bttv
driver.
This fixes bug #7234.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
i2c: Warn on i2c client creation failure
Warn when an i2c client creation fails. If we don't, the user will
never know something wrong happened, as i2c client creation is
typically called through an attach_adapter callback, those return value
we currently ignore for technical reasons.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c-core: Drop useless bitmaskings
The code generated is exactly the same.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c: __must_check fixes (core drivers)
Check for error on sysfs file creation.
Check for error on device registration.
Check for error on class device registration.
Greg, I am not familiar with completion, can you please tell me if I
need to take care of it in the error paths (as I did in this patch,
see /* Needed? */ comments), or if it isn't needed?
These patches were tested, including forced errors, so they should work
fine. But of course more testing can't hurt.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a bug in the handling of 'ignore' module parameters of I2C
client drivers.
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The attached patch marks i2c_smbus_write_block_data() and
i2c_smbus_write_i2c_block_data() buffers as const.
Signed-off-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>