[PATCH 3/4] ASoC: soc-dapm.h: Add a helper to build a DAPM widget dynamically

[Herve Codina <herve.codina@bootlin.com>]

The SND_SOC_DAPM_* helpers family are used to build widgets array in a
static way.

Introduce SND_SOC_DAPM_WIDGET() in order to use the SND_SOC_DAPM_*
helpers family in a dynamic way. The different SND_SOC_DAPM_* parameters
can be computed by the code and the widget can be built based on this
parameter computation.
For instance:
  static int create_widget(char *input_name)
  {
	struct snd_soc_dapm_widget widget;
	char name*;
	...
	name = input_name;
	if (!name)
		name = "default";

	widget = SND_SOC_DAPM_WIDGET(SND_SOC_DAPM_INPUT(name));
	...
  }

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
---
 include/sound/soc-dapm.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/sound/soc-dapm.h b/include/sound/soc-dapm.h
index 64915ebd641e..d6bb97fba8c9 100644
--- a/include/sound/soc-dapm.h
+++ b/include/sound/soc-dapm.h
@@ -276,7 +276,17 @@ struct soc_enum;
 	.reg = SND_SOC_NOPM, .event = dapm_pinctrl_event, \
 	.event_flags = SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_POST_PMD }
 
-
+/*
+ * Helper to create a widget 'dynamically'
+ * This can be used with any of the SND_SOC_DAPM_* widget helper.
+ * For instance:
+ *  struct snd_soc_dapm_widget widget;
+ *  ...
+ *  widget = SND_SOC_DAPM_WIDGET(SND_SOC_DAPM_INPUT(input_name));
+ */
+#define SND_SOC_DAPM_WIDGET(_widget)({ \
+		struct snd_soc_dapm_widget _w[1] = { _widget }; \
+	_w[0]; })
 
 /* dapm kcontrol types */
 #define SOC_DAPM_DOUBLE(xname, reg, lshift, rshift, max, invert) \
-- 
2.39.2