Commit graph android_kernel_sony_sdm845/Documentation/i2c/chips/max6875
Message SHA1
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>

Jean Delvare   commited 2007-07-12 14:12:29 +02:00
4b2643d7d9
[PATCH] I2C: max6875 documentation cleanup
Fix a spelling error and change a sysfs name.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

bgardner@wabtec.com   authored and   Greg Kroah-Hartman   commited 2005-09-05 09:14:05 -07:00
0283fe6c3b
[PATCH] I2C: update max6875 documentation
Updates to the max6875 driver documentation.
This brings the documentation in sync with the code, which was recently
simplified.

This patch is based off 2.6.13-rc2-mm2.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

bgardner@wabtec.com   authored and   Greg Kroah-Hartman   commited 2005-09-05 09:14:03 -07:00
93ffa43514
[PATCH] I2C: max6875 documentation update
Here is a proposed documentation update for the new max6875 i2c chip
driver.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Jean Delvare   authored and   Greg Kroah-Hartman   commited 2005-07-11 14:10:36 -07:00
089bd86632
[PATCH] max6875: new i2c device driver
This patch adds support for the MAX6875/MAX6874 chips.

Signed-off-by: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

BGardner@Wabtec.com   authored and   Greg Kroah-Hartman   commited 2005-06-21 21:52:05 -07:00
c3bc4caedd