ASoC: core: Add signed register volume control logic
Some codecs use signed volume control representation with non standard
register sizes, e.g. 6 or 7 bit signed integers.
This patch adds generic signed register volume control logic to
soc-core. Instead of a fixed width signed register control, this
implementation uses a 'min' value and the signed bit location to translate
it to an absolute volume. Using the 'sign_bit' we can calculate a
correct mask for the register values and translate it back into signed
integers of standard size.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 9a00147..a25f3cc 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -1067,6 +1067,7 @@
int min, max, platform_max;
int reg, rreg;
unsigned int shift, rshift;
+ unsigned int sign_bit;
unsigned int invert:1;
unsigned int autodisable:1;
};