ASoC: soc-core: add for_each_rtd_components() and replace

ALSA SoC has for_each_rtdcom() which is link list for
rtd-component which is called as rtdcom. The relationship image is like below

			       rtdcom	   rtdcom      rtdcom
			       component   component   component
	rtd->component_list -> list	-> list	    -> list ...

Here, the pointer get via normal link list is rtdcom,
Thus, current for_each loop is like below, and need to get
component via rtdcom->component

	for_each_rtdcom(rtd, rtdcom) {
		component = rtdcom->component;
		...
	}

but usually, user want to get pointer from for_each_xxx is component
directly, like below.

	for_each_rtd_component(rtd, rtdcom, component) {
		...
	}

This patch expands list_for_each_entry manually, and enable to get
component directly from for_each macro.
Because of it, the macro becoming difficult to read,
but macro itself becoming useful.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Link: https://lore.kernel.org/r/878spm64m4.wl-kuninori.morimoto.gx@renesas.com
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 6 insertions, 2 deletions

diff --git a/include/sound/soc.h b/include/sound/soc.h
index d730883626dc..320dcd440dab 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -739,8 +739,12 @@ struct snd_soc_rtdcom_list {
 struct snd_soc_component*
 snd_soc_rtdcom_lookup(struct snd_soc_pcm_runtime *rtd,
 		       const char *driver_name);
-#define for_each_rtdcom(rtd, rtdcom) \
-	list_for_each_entry(rtdcom, &(rtd)->component_list, list)
+#define for_each_rtd_components(rtd, rtdcom, _component)		\
+	for (rtdcom = list_first_entry(&(rtd)->component_list,		\
+				       typeof(*rtdcom), list);		\
+	     (&rtdcom->list != &(rtd)->component_list) &&		\
+		     (_component = rtdcom->component);			\
+	     rtdcom = list_next_entry(rtdcom, list))
 
 struct snd_soc_dai_link_component {
 	const char *name;