Split the handling of the I2C_RDWR and I2C_SMBUS ioctls to their own
functions. This limits the stack usage, saves one level of indentation
and makes the code more readable.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
Let i2c-dev deal properly with new-style i2c clients. Instead of
considering them always busy, it needs to check wether a driver is
bound to them or not.
This is still not completely correct, as the client could become
busy later, but the same problem already existed before new-style
clients were introduced. We'll want to fix it someday.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
This adds some "how does this work" comments to the i2c-dev driver,
plus separators between the three main components:
- The parallel list of i2c_adapters ("i2c_dev_list"), each of which
gets a "struct i2c_dev" and a /dev/i2c-X character special file.
- An i2cdev_driver gets adapter add/remove notifications, which are
used to maintain that list of adapters.
- Special file operations, which let userspace talk either directly to
the adapter (for i2c_msg operations) or through cached addressing info
using an anonymous i2c_client (never registered anywhere).
Plus there's the usual module load/unload record keeping.
After making sense of this code, I think that the anonymous i2c_client
is pretty shady. But since it's never registered, using this code with
a system set up for "new style" I2C drivers is no more complicated than
always using the I2C_SLAVE_FORCE ioctl (instead of I2C_SLAVE).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
The I2C_M_RECV_LEN calling convention for i2c_mesg.flags involves
playing games with reported buffer lengths. (They start out less
than their actual size, and the length is then modified to reflect
how many bytes were delivered ... which one hopes is less than the
presumed actual size.) Refuse to play such error prone games across
the boundary between userspace and kernel.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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>
Remove includes of <linux/smp_lock.h> where it is not used/needed.
Suggested by Al Viro.
Builds cleanly on x86_64, i386, alpha, ia64, powerpc, sparc,
sparc64, and arm (all 59 defconfigs).
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many struct file_operations in the kernel can be "const". Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data. In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Refactor kfree(i2c_dev) into return_i2c_dev(). This saves some
code and makes more sense, as the memory is allocated in
get_free_i2c_dev().
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
device_create() returns error code as pointer on failures.
This patch checks the return value of device_create() by using IS_ERR().
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
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 speeds up the I2C_FUNCS ioctl by 5 to 8% in my tests.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Laughed-at-by: Mark M. Hoffman <mhoffman@lightlink.com>
i2c-dev: attach/detach_adapter cleanups
* Only print that an adapter was attached when it succeeds.
* i2c_dev == NULL on detach simply means that the attach failed
before, this isn't an error per se.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c: __must_check fixes (i2c-dev)
Check for error on sysfs file creation.
Check for error on device creation.
Delete sysfs file on device destruction.
I couldn't test this one beyond compilation, as it applies on top of
another patch in Greg's tree [1] which breaks all my systems when I
apply it (my udev isn't recent enough.) Anyone with bleeding edge udev
is welcome to test and report.
[1] http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/i2c/i2c-dev-device.patch
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c-dev: Drop the client template
Drop the i2c-dev client template. This saves about 360 bytes of
memory. I got the idea from a similar cleanup Hans-Frieder Vogt
made to i2c-nforce2 recently.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c-dev: Use a list for data storage
Use a list instead of a static array for storing the i2c-dev data.
Given that most systems have less than 10 i2c busses, most of the
space was wasted, so this saves around 1 kB of memory (2 kB on 64-bit
archs.)
The drawback is that lookup was in O(1) and is now in O(N), but given
that the values of N are always small, I don't think this is a problem.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c-dev: Cleanups
* We no more need to include platform_device.h.
* Delete the to_i2c_dev macro, which is no more used (and no more valid
either.)
* Drop i2c_dev.minor. Now that the minor number always matches the i2c
adapter number, this field is redundant with i2c_dev.adap->nr.
* Delete i2c_dev_get_by_adapter() which is now redundant with
i2c_dev_get_by_minor() for the same reason.
* Drop the local variable dev in i2cdev_attach_adapter(), we can
easily do without it.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
I2C creates some sysfs nodes in the wrong places: not as children of parent
controllers, but as their peers (!). This puts them into the right place
always, instead of just when the adapter is on the platform bus.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Given that implementing i2c_driver.command is optional, there is no
point in an empty implementation thereof.
Signed-off-by: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Cc: Michael Geng <linux@MichaelGeng.de>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
i2c-dev doesn't use the reference counting logic of struct class_device so move
it to the dynamic method. This makes the code paths simpler and the driver
smaller.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jean Delvare <khali@linux-fr.org>
Now that i2c_add_driver() doesn't need the module owner to be set by
hand, we can delete it from the drivers. This patch catches all of the
drivers that I found in the current tree (if a driver sets the .owner by
hand, it's not a problem, just not needed.)
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Jean Delvare <khali@linux-fr.org>
We should use the i2c_driver.driver's .name and .owner fields
instead of the i2c_driver's ones.
This patch updates the core of the i2c drivers: it removes .name and
.owner fields from the struct i2c_device and modify various
functions to use struct device fields instead.
Signed-off-by: Laurent Riffard <laurent.riffard@free.fr>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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>
Convert everyone who uses platform_bus_type to include
linux/platform_device.h.
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc instead of kmalloc+memset in all remaining i2c bus and
chip drivers.
Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Cleanup the ioctl debug message in i2c-dev. In particular, the minor
number is redundant now that the minor number and the adapter number
are kept in sync.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The debugging messages in i2c-core are more confusing than helpful. Some
lack their trailing newline, some lack a prefix, some are redundant,
some lack precious information. Here is my attempt to introduce some
standardization in there.
I also changed two messages in i2c-dev to make it clear they come from
i2c-dev.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes a misspelling in a comment section.
Signed-off-by: Tobias Klauser <tklauser@nuerscht.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Files that don't use CONFIG_* stuff shouldn't include config.h
Files that use CONFIG_* stuff should include config.h
It's that simple. ;-)
Signed-off-by: Alexey Dobriyan <adobriyan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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!
Jean Delvare