ASoC: add new simple-card-utils.c

Current ALSA SoC has simple-card driver which is supporting both
platform and DT probe.
Now, some sound cards driver are created based on simple-card.
They have similar feature or function, but implemented separately
on each drivers. This is a waste of code.
OTOH, merging these driver into same driver is highly risk,
because it will be very difficult to keep compatibility.
More over, ALSA SoC want to have graph base of DT feature in the
future. Maybe it want to use simple-card like feature / function.
Because of these background, this patch creates simple-card
helper utils, and provides common function to each drivers.
1st is asoc_simple_card_parse_daifmt()
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

include/sound/simple_card_utils.h

+/*
+ * simple_card_core.h
+ *
+ * Copyright (c) 2016 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __SIMPLE_CARD_CORE_H
+#define __SIMPLE_CARD_CORE_H
+
+#include <sound/soc.h>
+
+int asoc_simple_card_parse_daifmt(struct device *dev,
+				  struct device_node *node,
+				  struct device_node *codec,
+				  char *prefix,
+				  unsigned int *retfmt);
+
+#endif /* __SIMPLE_CARD_CORE_H */

sound/soc/generic/Kconfig

+config SND_SIMPLE_CARD_UTILS
+       tristate
+
 config SND_SIMPLE_CARD
 	tristate "ASoC Simple sound card support"
 	help

sound/soc/generic/Makefile

+obj-$(CONFIG_SND_SIMPLE_CARD_UTILS) := simple-card-utils.o
+
 snd-soc-simple-card-objs	:= simple-card.o
 
 obj-$(CONFIG_SND_SIMPLE_CARD)	+= snd-soc-simple-card.o

sound/soc/generic/simple-card-utils.c

+/*
+ * simple-card-core.c
+ *
+ * Copyright (c) 2016 Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/of.h>
+#include <sound/simple_card_utils.h>
+
+int asoc_simple_card_parse_daifmt(struct device *dev,
+				  struct device_node *node,
+				  struct device_node *codec,
+				  char *prefix,
+				  unsigned int *retfmt)
+{
+	struct device_node *bitclkmaster = NULL;
+	struct device_node *framemaster = NULL;
+	int prefix_len = prefix ? strlen(prefix) : 0;
+	unsigned int daifmt;
+
+	daifmt = snd_soc_of_parse_daifmt(node, prefix,
+					 &bitclkmaster, &framemaster);
+	daifmt &= ~SND_SOC_DAIFMT_MASTER_MASK;
+
+	if (prefix_len && !bitclkmaster && !framemaster) {
+		/*
+		 * No dai-link level and master setting was not found from
+		 * sound node level, revert back to legacy DT parsing and
+		 * take the settings from codec node.
+		 */
+		dev_dbg(dev, "Revert to legacy daifmt parsing\n");
+
+		daifmt = snd_soc_of_parse_daifmt(codec, NULL, NULL, NULL) |
+			(daifmt & ~SND_SOC_DAIFMT_CLOCK_MASK);
+	} else {
+		if (codec == bitclkmaster)
+			daifmt |= (codec == framemaster) ?
+				SND_SOC_DAIFMT_CBM_CFM : SND_SOC_DAIFMT_CBM_CFS;
+		else
+			daifmt |= (codec == framemaster) ?
+				SND_SOC_DAIFMT_CBS_CFM : SND_SOC_DAIFMT_CBS_CFS;
+	}
+
+	of_node_put(bitclkmaster);
+	of_node_put(framemaster);
+
+	*retfmt = daifmt;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(asoc_simple_card_parse_daifmt);