ASoC: Add signal generator widget type

A signal generator behaves as an input would but is not considered for
any of the special behaviour associated with external input pins. This
is especially useful when automatically working out not connected widgets.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@ti.com>

include/sound/soc-dapm.h

@@ -43,6 +43,9 @@
 	.num_kcontrols = 0}
 
 /* platform domain */
+#define SND_SOC_DAPM_SIGGEN(wname) \
+{	.id = snd_soc_dapm_siggen, .name = wname, .kcontrol_news = NULL, \
+	.num_kcontrols = 0, .reg = SND_SOC_NOPM }
 #define SND_SOC_DAPM_INPUT(wname) \
 {	.id = snd_soc_dapm_input, .name = wname, .kcontrol_news = NULL, \
 	.num_kcontrols = 0, .reg = SND_SOC_NOPM }
@@ -410,6 +413,7 @@ enum snd_soc_dapm_type {
 	snd_soc_dapm_supply,		/* power/clock supply */
 	snd_soc_dapm_aif_in,		/* audio interface input */
 	snd_soc_dapm_aif_out,		/* audio interface output */
+	snd_soc_dapm_siggen,		/* signal generator */
 };
 
 /*

sound/soc/soc-dapm.c

@@ -339,6 +339,7 @@ static void dapm_set_path_status(struct snd_soc_dapm_widget *w,
 	case snd_soc_dapm_output:
 	case snd_soc_dapm_adc:
 	case snd_soc_dapm_input:
+	case snd_soc_dapm_siggen:
 	case snd_soc_dapm_dac:
 	case snd_soc_dapm_micbias:
 	case snd_soc_dapm_vmid:
@@ -772,6 +773,11 @@ static int is_connected_input_ep(struct snd_soc_dapm_widget *widget)
 			return widget->inputs;
 		}
 
+		/* signal generator */
+		if (widget->id == snd_soc_dapm_siggen) {
+			widget->inputs = snd_soc_dapm_suspend_check(widget);
+			return widget->inputs;
+		}
 	}
 
 	list_for_each_entry(path, &widget->sources, list_sink) {
@@ -1982,6 +1988,7 @@ static int snd_soc_dapm_add_route(struct snd_soc_dapm_context *dapm,
 	case snd_soc_dapm_out_drv:
 	case snd_soc_dapm_input:
 	case snd_soc_dapm_output:
+	case snd_soc_dapm_siggen:
 	case snd_soc_dapm_micbias:
 	case snd_soc_dapm_vmid:
 	case snd_soc_dapm_pre: