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Commit Graph

6 Commits

Author SHA1 Message Date
Jean Delvare
bd8d421f7c i2c: Convert the max6875 driver to a new-style i2c driver
The new-style max6875 driver implements the optional detect() callback
to cover the use cases of the legacy driver. I'm curious if anyone
really needs this though, so it might be removed in the feature.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-07-16 19:30:07 +02:00
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
bgardner@wabtec.com
0283fe6c3b [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>
2005-09-05 09:14:05 -07:00
bgardner@wabtec.com
93ffa43514 [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>
2005-09-05 09:14:03 -07:00
Jean Delvare
089bd86632 [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>
2005-07-11 14:10:36 -07:00
BGardner@Wabtec.com
c3bc4caedd [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>
2005-06-21 21:52:05 -07:00