ASoC: twl6040 - add method to query HS DC offset step size in mV

Provide a method for mach drivers to query the HS DC offset step size in mV.

Signed-off-by: Liam Girdwood <lrg@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/codecs/twl6040.c b/sound/soc/codecs/twl6040.c
index 5b9c79b..284dd2e 100644
--- a/sound/soc/codecs/twl6040.c
+++ b/sound/soc/codecs/twl6040.c
@@ -1052,6 +1052,19 @@
 }
 EXPORT_SYMBOL_GPL(twl6040_get_trim_value);
 
+int twl6040_get_hs_step_size(struct snd_soc_codec *codec)
+{
+	struct twl6040 *twl6040 = codec->control_data;
+
+	if (twl6040_get_revid(twl6040) < TWL6040_REV_ES1_2)
+		/* For ES under ES_1.3 HS step is 2 mV */
+		return 2;
+	else
+		/* For ES_1.3 HS step is 1 mV */
+		return 1;
+}
+EXPORT_SYMBOL_GPL(twl6040_get_hs_step_size);
+
 static const struct snd_kcontrol_new twl6040_snd_controls[] = {
 	/* Capture gains */
 	SOC_DOUBLE_TLV("Capture Preamplifier Volume",
diff --git a/sound/soc/codecs/twl6040.h b/sound/soc/codecs/twl6040.h
index ef273f1..0611406 100644
--- a/sound/soc/codecs/twl6040.h
+++ b/sound/soc/codecs/twl6040.h
@@ -39,5 +39,6 @@
 			    struct snd_soc_jack *jack, int report);
 int twl6040_get_clk_id(struct snd_soc_codec *codec);
 int twl6040_get_trim_value(struct snd_soc_codec *codec, enum twl6040_trim trim);
+int twl6040_get_hs_step_size(struct snd_soc_codec *codec);
 
 #endif /* End of __TWL6040_H__ */