[alsa-devel] [PATCH 0/2] ASoC: core: volume control using signed register values
Hi,
There are a lot of codecs using negative and positive volume control ranges as values in their registers. These two patches add support for arbitrary size signed integer values in registers.
Regards,
Markus
Markus Pargmann (2): ASoC: core: Add signed register volume control logic ASoC: soc.h: Add SOC_DOUBLE_R_S_TLV
include/sound/soc.h | 15 ++++++++++++ sound/soc/soc-core.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 76 insertions(+), 7 deletions(-)
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 --- include/sound/soc.h | 1 + sound/soc/soc-core.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 62 insertions(+), 7 deletions(-)
diff --git a/include/sound/soc.h b/include/sound/soc.h index 1f741cb..5907583 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -1053,6 +1053,7 @@ 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; }; diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index a66783e..de61159 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -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 * @uinfo: control element information @@ -2742,7 +2784,7 @@ 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); @@ -2768,11 +2810,16 @@ 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]; @@ -2780,10 +2827,12 @@ 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]; @@ -2814,6 +2863,8 @@ 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; @@ -2821,13 +2872,16 @@ 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) {
Add a macro for signed mixer with two registers and tlv array.
Signed-off-by: Markus Pargmann mpa@pengutronix.de --- include/sound/soc.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/include/sound/soc.h b/include/sound/soc.h index 5907583..e9084ed 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -45,6 +45,11 @@ ((unsigned long)&(struct soc_mixer_control) \ {.reg = xlreg, .rreg = xrreg, .shift = xshift, .rshift = xshift, \ .max = xmax, .platform_max = xmax, .invert = xinvert}) +#define SOC_DOUBLE_R_S_VALUE(xlreg, xrreg, xshift, xmin, xmax, xsign_bit, xinvert) \ + ((unsigned long)&(struct soc_mixer_control) \ + {.reg = xlreg, .rreg = xrreg, .shift = xshift, .rshift = xshift, \ + .max = xmax, .min = xmin, .platform_max = xmax, .sign_bit = xsign_bit, \ + .invert = xinvert}) #define SOC_DOUBLE_R_RANGE_VALUE(xlreg, xrreg, xshift, xmin, xmax, xinvert) \ ((unsigned long)&(struct soc_mixer_control) \ {.reg = xlreg, .rreg = xrreg, .shift = xshift, .rshift = xshift, \ @@ -152,6 +157,15 @@ {.reg = xreg, .rreg = xrreg, \ .shift = xshift, .rshift = xshift, \ .max = xmax, .min = xmin} } +#define SOC_DOUBLE_R_S_TLV(xname, reg_left, reg_right, xshift, xmin, xmax, xsign_bit, xinvert, tlv_array) \ +{ .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = (xname),\ + .access = SNDRV_CTL_ELEM_ACCESS_TLV_READ |\ + SNDRV_CTL_ELEM_ACCESS_READWRITE,\ + .tlv.p = (tlv_array), \ + .info = snd_soc_info_volsw, \ + .get = snd_soc_get_volsw, .put = snd_soc_put_volsw, \ + .private_value = SOC_DOUBLE_R_S_VALUE(reg_left, reg_right, xshift, \ + xmin, xmax, xsign_bit, xinvert) } #define SOC_DOUBLE_S8_TLV(xname, xreg, xmin, xmax, tlv_array) \ { .iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = (xname), \ .access = SNDRV_CTL_ELEM_ACCESS_TLV_READ | \
On Thu, Jan 16, 2014 at 04:02:09PM +0100, Markus Pargmann wrote:
There are a lot of codecs using negative and positive volume control ranges as values in their registers. These two patches add support for arbitrary size signed integer values in registers.
Applied both, thanks.
participants (2)
-
Mark Brown -
Markus Pargmann