Re: [PATCH] ad525x_dpot: new driver for AD525x digital potentiometers

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 17 Sep 2009 00:22:37 -0400
Mike Frysinger <vapier@gentoo.org> wrote:

> This driver supports the non-volatile digital potentiometers via I2C:
> AD5258, AD5259, AD5251, AD5252, AD5253, AD5254, and AD5255
> 
> It provides a sysfs interface to each device for reading/writing.

This sysfs interface is by far the most important aspect of this
driver.  For both its users and for its reviewers.

Yet you tell us nothing about it!  Not in code comments, not in the
changelog, not in supporting documentation.

So some poor idiot (ie: me) is left having to scratch his way through
the implementation trying to work out what the propoed userspace
interface is supposed to look like.

Then I come across something this:

+	if (reg & AD525X_REG_TOL)
+		return sprintf(buf, "0x%04x\n", value & 0xFFFF);
+	else
+		return sprintf(buf, "%u\n", value & data->rdac_mask);

which makes me suspect that the proposed userspace interface is quite
poor.


Patch not applied!  Not even close.