ASoC: core: Add strobe control

Added support for a control that strobes a bit in
a register to high then back to low (or the inverse).

This is typically useful for hardware that requires
strobing a singe bit to trigger some functionality
and where exposing the bit in a normal single control
would require the user to first manually set then
again unset the bit again for the strobe to trigger.

Added convenience macro.

SOC_SINGLE_STROBE

Added accessor implementations.

snd_soc_get_strobe
snd_soc_put_strobe

Signed-off-by: Kristoffer KARLSSON <kristoffer.karlsson@stericsson.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc.h

@@ -219,6 +219,10 @@
 		{.regbase = xregbase, .regcount = xregcount, .nbits = xnbits, \
 		.invert = xinvert, .min = xmin, .max = xmax} }
 
+#define SOC_SINGLE_STROBE(xname, xreg, xshift, xinvert) \
+	SOC_SINGLE_EXT(xname, xreg, xshift, 1, xinvert, \
+		snd_soc_get_strobe, snd_soc_put_strobe)
+
 /*
  * Simplified versions of above macros, declaring a struct and calculating
  * ARRAY_SIZE internally
@@ -461,6 +465,10 @@ int snd_soc_get_xr_sx(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
 int snd_soc_put_xr_sx(struct snd_kcontrol *kcontrol,
 	struct snd_ctl_elem_value *ucontrol);
+int snd_soc_get_strobe(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol);
+int snd_soc_put_strobe(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol);
 
 /**
  * struct snd_soc_reg_access - Describes whether a given register is

sound/soc/soc-core.c

@@ -3009,6 +3009,69 @@ int snd_soc_put_xr_sx(struct snd_kcontrol *kcontrol,
 }
 EXPORT_SYMBOL_GPL(snd_soc_put_xr_sx);
 
+/**
+ * snd_soc_get_strobe - strobe get callback
+ * @kcontrol: mixer control
+ * @ucontrol: control element information
+ *
+ * Callback get the value of a strobe mixer control.
+ *
+ * Returns 0 for success.
+ */
+int snd_soc_get_strobe(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *mc =
+		(struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+	unsigned int reg = mc->reg;
+	unsigned int shift = mc->shift;
+	unsigned int mask = 1 << shift;
+	unsigned int invert = mc->invert != 0;
+	unsigned int val = snd_soc_read(codec, reg) & mask;
+
+	if (shift != 0 && val != 0)
+		val = val >> shift;
+	ucontrol->value.enumerated.item[0] = val ^ invert;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(snd_soc_get_strobe);
+
+/**
+ * snd_soc_put_strobe - strobe put callback
+ * @kcontrol: mixer control
+ * @ucontrol: control element information
+ *
+ * Callback strobe a register bit to high then low (or the inverse)
+ * in one pass of a single mixer enum control.
+ *
+ * Returns 1 for success.
+ */
+int snd_soc_put_strobe(struct snd_kcontrol *kcontrol,
+	struct snd_ctl_elem_value *ucontrol)
+{
+	struct soc_mixer_control *mc =
+		(struct soc_mixer_control *)kcontrol->private_value;
+	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
+	unsigned int reg = mc->reg;
+	unsigned int shift = mc->shift;
+	unsigned int mask = 1 << shift;
+	unsigned int invert = mc->invert != 0;
+	unsigned int strobe = ucontrol->value.enumerated.item[0] != 0;
+	unsigned int val1 = (strobe ^ invert) ? mask : 0;
+	unsigned int val2 = (strobe ^ invert) ? 0 : mask;
+	int err;
+
+	err = snd_soc_update_bits_locked(codec, reg, mask, val1);
+	if (err < 0)
+		return err;
+
+	err = snd_soc_update_bits_locked(codec, reg, mask, val2);
+	return err;
+}
+EXPORT_SYMBOL_GPL(snd_soc_put_strobe);
+
 /**
  * snd_soc_dai_set_sysclk - configure DAI system or master clock.
  * @dai: DAI