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ASoC: core: Add signed register volume control logic

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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>
This commit is contained in:
Markus Pargmann 2014-01-16 16:02:10 +01:00 committed by Mark Brown
parent 38dbfb59d1
commit f227b88f0f
2 changed files with 62 additions and 7 deletions
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1
include/sound/soc.h
View File

@ -1067,6 +1067,7 @@ struct soc_mixer_control {
int min, max, platform_max;
int reg, rreg;
unsigned int shift, rshift;
unsigned int sign_bit;
unsigned int invert:1;
unsigned int autodisable:1;
};

68
sound/soc/soc-core.c
View File

@ -2715,6 +2715,48 @@ int snd_soc_put_value_enum_double(struct snd_kcontrol *kcontrol,
}
EXPORT_SYMBOL_GPL(snd_soc_put_value_enum_double);
/**
* snd_soc_read_signed - Read a codec register and interprete as signed value
* @codec: codec
* @reg: Register to read
* @mask: Mask to use after shifting the register value
* @shift: Right shift of register value
* @sign_bit: Bit that describes if a number is negative or not.
*
* This functions reads a codec register. The register value is shifted right
* by 'shift' bits and masked with the given 'mask'. Afterwards it translates
* the given registervalue into a signed integer if sign_bit is non-zero.
*
* Returns the register value as signed int.
*/
static int snd_soc_read_signed(struct snd_soc_codec *codec, unsigned int reg,
unsigned int mask, unsigned int shift, unsigned int sign_bit)
{
int ret;
unsigned int val;
val = (snd_soc_read(codec, reg) >> shift) & mask;
if (!sign_bit)
return val;
/* non-negative number */
if (!(val & BIT(sign_bit)))
return val;
ret = val;
/*
* The register most probably does not contain a full-sized int.
* Instead we have an arbitrary number of bits in a signed
* representation which has to be translated into a full-sized int.
* This is done by filling up all bits above the sign-bit.
*/
ret |= ~((int)(BIT(sign_bit) - 1));
return ret;
}
/**
* snd_soc_info_volsw - single mixer info callback
* @kcontrol: mixer control
@ -2743,7 +2785,7 @@ int snd_soc_info_volsw(struct snd_kcontrol *kcontrol,
uinfo->count = snd_soc_volsw_is_stereo(mc) ? 2 : 1;
uinfo->value.integer.min = 0;
uinfo->value.integer.max = platform_max;
uinfo->value.integer.max = platform_max - mc->min;
return 0;
}
EXPORT_SYMBOL_GPL(snd_soc_info_volsw);
@ -2769,11 +2811,16 @@ int snd_soc_get_volsw(struct snd_kcontrol *kcontrol,
unsigned int shift = mc->shift;
unsigned int rshift = mc->rshift;
int max = mc->max;
int min = mc->min;
int sign_bit = mc->sign_bit;
unsigned int mask = (1 << fls(max)) - 1;
unsigned int invert = mc->invert;
ucontrol->value.integer.value[0] =
(snd_soc_read(codec, reg) >> shift) & mask;
if (sign_bit)
mask = BIT(sign_bit + 1) - 1;
ucontrol->value.integer.value[0] = snd_soc_read_signed(codec, reg, mask,
shift, sign_bit) - min;
if (invert)
ucontrol->value.integer.value[0] =
max - ucontrol->value.integer.value[0];
@ -2781,10 +2828,12 @@ int snd_soc_get_volsw(struct snd_kcontrol *kcontrol,
if (snd_soc_volsw_is_stereo(mc)) {
if (reg == reg2)
ucontrol->value.integer.value[1] =
(snd_soc_read(codec, reg) >> rshift) & mask;
snd_soc_read_signed(codec, reg, mask, rshift,
sign_bit) - min;
else
ucontrol->value.integer.value[1] =
(snd_soc_read(codec, reg2) >> shift) & mask;
snd_soc_read_signed(codec, reg2, mask, shift,
sign_bit) - min;
if (invert)
ucontrol->value.integer.value[1] =
max - ucontrol->value.integer.value[1];
@ -2815,6 +2864,8 @@ int snd_soc_put_volsw(struct snd_kcontrol *kcontrol,
unsigned int shift = mc->shift;
unsigned int rshift = mc->rshift;
int max = mc->max;
int min = mc->min;
unsigned int sign_bit = mc->sign_bit;
unsigned int mask = (1 << fls(max)) - 1;
unsigned int invert = mc->invert;
int err;
@ -2822,13 +2873,16 @@ int snd_soc_put_volsw(struct snd_kcontrol *kcontrol,
unsigned int val2 = 0;
unsigned int val, val_mask;
val = (ucontrol->value.integer.value[0] & mask);
if (sign_bit)
mask = BIT(sign_bit + 1) - 1;
val = ((ucontrol->value.integer.value[0] + min) & mask);
if (invert)
val = max - val;
val_mask = mask << shift;
val = val << shift;
if (snd_soc_volsw_is_stereo(mc)) {
val2 = (ucontrol->value.integer.value[1] & mask);
val2 = ((ucontrol->value.integer.value[1] + min) & mask);
if (invert)
val2 = max - val2;
if (reg == reg2) {