ASoC: add snd_soc_of_parse_daifmt() for DeviceTree

This patch adds snd_soc_of_parse_daifmt() and supports below style on DT.

        [prefix]format = "i2c";
        [prefix]clock-gating = "continuous";
        [prefix]bitclock-inversion;
        [prefix]bitclock-master;
        [prefix]frame-master;

Each driver can use specific [prefix]
(ex simple-card,cpu,dai,format = xxx;)

This sample will be
SND_SOC_DAIFMT_I2S | SND_SOC_DAIFMT_CONT |
SND_SOC_DAIFMT_IB_NF | SND_SOC_DAIFMT_CBM_CFM

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

include/sound/soc.h

@@ -1171,6 +1171,8 @@ int snd_soc_of_parse_card_name(struct snd_soc_card *card,
 			       const char *propname);
 int snd_soc_of_parse_audio_routing(struct snd_soc_card *card,
 				   const char *propname);
+unsigned int snd_soc_of_parse_daifmt(struct device_node *np,
+				     const char *prefix);
 
 #include <sound/soc-dai.h>
 

sound/soc/soc-core.c

@@ -4208,6 +4208,121 @@ int snd_soc_of_parse_audio_routing(struct snd_soc_card *card,
 }
 EXPORT_SYMBOL_GPL(snd_soc_of_parse_audio_routing);
 
+unsigned int snd_soc_of_parse_daifmt(struct device_node *np,
+				     const char *prefix)
+{
+	int ret, i;
+	char prop[128];
+	unsigned int format = 0;
+	int bit, frame;
+	const char *str;
+	struct {
+		char *name;
+		unsigned int val;
+	} of_fmt_table[] = {
+		{ "i2s",	SND_SOC_DAIFMT_I2S },
+		{ "right_j",	SND_SOC_DAIFMT_RIGHT_J },
+		{ "left_j",	SND_SOC_DAIFMT_LEFT_J },
+		{ "dsp_a",	SND_SOC_DAIFMT_DSP_A },
+		{ "dsp_b",	SND_SOC_DAIFMT_DSP_B },
+		{ "ac97",	SND_SOC_DAIFMT_AC97 },
+		{ "pdm",	SND_SOC_DAIFMT_PDM},
+		{ "msb",	SND_SOC_DAIFMT_MSB },
+		{ "lsb",	SND_SOC_DAIFMT_LSB },
+	}, of_clock_table[] = {
+		{ "continuous",	SND_SOC_DAIFMT_CONT },
+		{ "gated",	SND_SOC_DAIFMT_GATED },
+	};
+
+	if (!prefix)
+		prefix = "";
+
+	/*
+	 * check "[prefix]format = xxx"
+	 * SND_SOC_DAIFMT_FORMAT_MASK area
+	 */
+	snprintf(prop, sizeof(prop), "%sformat", prefix);
+	ret = of_property_read_string(np, prop, &str);
+	if (ret == 0) {
+		for (i = 0; i < ARRAY_SIZE(of_fmt_table); i++) {
+			if (strcmp(str, of_fmt_table[i].name) == 0) {
+				format |= of_fmt_table[i].val;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * check "[prefix]clock-gating = xxx"
+	 * SND_SOC_DAIFMT_CLOCK_MASK area
+	 */
+	snprintf(prop, sizeof(prop), "%sclock-gating", prefix);
+	ret = of_property_read_string(np, prop, &str);
+	if (ret == 0) {
+		for (i = 0; i < ARRAY_SIZE(of_clock_table); i++) {
+			if (strcmp(str, of_clock_table[i].name) == 0) {
+				format |= of_clock_table[i].val;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * check "[prefix]bitclock-inversion"
+	 * check "[prefix]frame-inversion"
+	 * SND_SOC_DAIFMT_INV_MASK area
+	 */
+	snprintf(prop, sizeof(prop), "%sbitclock-inversion", prefix);
+	bit = !!of_get_property(np, prop, NULL);
+
+	snprintf(prop, sizeof(prop), "%sframe-inversion", prefix);
+	frame = !!of_get_property(np, prop, NULL);
+
+	switch ((bit << 4) + frame) {
+	case 0x11:
+		format |= SND_SOC_DAIFMT_IB_IF;
+		break;
+	case 0x10:
+		format |= SND_SOC_DAIFMT_IB_NF;
+		break;
+	case 0x01:
+		format |= SND_SOC_DAIFMT_NB_IF;
+		break;
+	default:
+		/* SND_SOC_DAIFMT_NB_NF is default */
+		break;
+	}
+
+	/*
+	 * check "[prefix]bitclock-master"
+	 * check "[prefix]frame-master"
+	 * SND_SOC_DAIFMT_MASTER_MASK area
+	 */
+	snprintf(prop, sizeof(prop), "%sbitclock-master", prefix);
+	bit = !!of_get_property(np, prop, NULL);
+
+	snprintf(prop, sizeof(prop), "%sframe-master", prefix);
+	frame = !!of_get_property(np, prop, NULL);
+
+	switch ((bit << 4) + frame) {
+	case 0x11:
+		format |= SND_SOC_DAIFMT_CBM_CFM;
+		break;
+	case 0x10:
+		format |= SND_SOC_DAIFMT_CBM_CFS;
+		break;
+	case 0x01:
+		format |= SND_SOC_DAIFMT_CBS_CFM;
+		break;
+	default:
+		format |= SND_SOC_DAIFMT_CBS_CFS;
+		break;
+	}
+
+	return format;
+}
+EXPORT_SYMBOL_GPL(snd_soc_of_parse_daifmt);
+
 static int __init snd_soc_init(void)
 {
 #ifdef CONFIG_DEBUG_FS