From: H Hartley Sweeten <hsweeten@visionengravers.com>
Date: Mon, 20 Oct 2014 18:34:11 +0000 (-0700)
Subject: staging: comedi: addi_apci_3120: remove unipolar range from analog outputs
X-Git-Tag: omap-for-v3.19/fixes-rc1~73^2~815
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12d984ed512aa20b46ba16abf3c4f64c6a893fe7;p=pandora-kernel.git

staging: comedi: addi_apci_3120: remove unipolar range from analog outputs

The analog outputs of the APCI-3120 have a 14-bit bipolar range and use straight
binary values (0x0000 = -10V to 0x3fff = +10V) to set the outputs. This driver
tries to fake a unipolar range by munging the comedi data values to only output
0V to +10V signals (0x0000 to 0x1fff values are munged to 0x2000 - 0x3fff).

This causes problems with the comedilib API functions that convert between comedi
values and physical values. It's also possible for the user to pass a data value
that would get munged and actually change the wrong channel.

Fix this by change the subdevice range_table to range_bipolar10 and remove the
munging in apci3120_ao_insn_write().

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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