[PATCH v3 6/7] ASoC: qcom: common: add DAI-node TDM slot helpers

[Prasad Kumpatla <prasad.kumpatla@oss.qualcomm.com>]

Add common helpers to parse standard dai-tdm-slot-* properties from the
CPU and codec child nodes of a backend DAI link and apply the result to
the active DAIs.

QCOM machine drivers already use qcom_snd_parse_of() to build links from
DT, but they lacked a shared helper to translate endpoint TDM properties
into snd_soc_dai_set_tdm_slot() calls. Boards therefore had to carry ad
hoc parsing or rely on non-standard DT properties.

The helpers parse endpoint masks, validate the shared slot count and
slot width, and program CPU and codec DAIs with the resulting slot
configuration. A cfg-based apply helper is provided for callers that
already parsed the DT data and want to avoid a second DT traversal.

Signed-off-by: Prasad Kumpatla <prasad.kumpatla@oss.qualcomm.com>
---
 sound/soc/qcom/common.c | 165 ++++++++++++++++++++++++++++++++++++++++
 sound/soc/qcom/common.h |  14 ++++
 2 files changed, 179 insertions(+)

diff --git a/sound/soc/qcom/common.c b/sound/soc/qcom/common.c
index edc461169..08949b2c4 100644
--- a/sound/soc/qcom/common.c
+++ b/sound/soc/qcom/common.c
@@ -23,6 +23,171 @@ static const struct snd_soc_dapm_widget qcom_jack_snd_widgets[] = {
 	SND_SOC_DAPM_SPK("DP7 Jack", NULL),
 };
 
+static struct device_node *qcom_snd_get_link_node(struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
+	struct snd_soc_card *card = rtd->card;
+	struct device_node *np;
+	struct device_node *cpu_np;
+	struct of_phandle_args args;
+	int ret;
+
+	if (!card->dev || !card->dev->of_node)
+		return NULL;
+
+	for_each_available_child_of_node(card->dev->of_node, np) {
+		cpu_np = of_get_child_by_name(np, "cpu");
+		if (!cpu_np)
+			continue;
+
+		ret = of_parse_phandle_with_args(cpu_np, "sound-dai", "#sound-dai-cells", 0,
+						 &args);
+		of_node_put(cpu_np);
+		if (ret)
+			continue;
+
+		if (args.np == rtd->dai_link->cpus[0].of_node &&
+		    args.args_count == 1 && args.args[0] == cpu_dai->id) {
+			of_node_put(args.np);
+			return np;
+		}
+
+		of_node_put(args.np);
+	}
+
+	return NULL;
+}
+
+static int qcom_snd_parse_tdm_slot(struct device_node *np,
+				   struct qcom_snd_tdm_slot_cfg *cfg)
+{
+	memset(cfg, 0, sizeof(*cfg));
+
+	return snd_soc_of_parse_tdm_slot(np, &cfg->tx_mask, &cfg->rx_mask,
+					 &cfg->slots, &cfg->slot_width);
+}
+
+static int qcom_snd_normalize_tdm_slots(struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+					struct qcom_snd_tdm_slot_cfg *codec_cfg)
+{
+	unsigned int slots;
+	unsigned int slot_width;
+
+	if (cpu_cfg->slots && codec_cfg->slots && cpu_cfg->slots != codec_cfg->slots)
+		return -EINVAL;
+
+	if (cpu_cfg->slot_width && codec_cfg->slot_width &&
+	    cpu_cfg->slot_width != codec_cfg->slot_width)
+		return -EINVAL;
+
+	slots = cpu_cfg->slots ?: codec_cfg->slots;
+	if (!slots)
+		return 0;
+
+	slot_width = cpu_cfg->slot_width ?: codec_cfg->slot_width;
+	if (!slot_width)
+		return -EINVAL;
+
+	cpu_cfg->slots = slots;
+	codec_cfg->slots = slots;
+	cpu_cfg->slot_width = slot_width;
+	codec_cfg->slot_width = slot_width;
+
+	return 0;
+}
+
+static int qcom_snd_parse_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd,
+					struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+					struct qcom_snd_tdm_slot_cfg *codec_cfg)
+{
+	struct device_node *link_np;
+	struct device_node *cpu_np = NULL;
+	struct device_node *codec_np = NULL;
+	int ret;
+
+	link_np = qcom_snd_get_link_node(rtd);
+	if (!link_np)
+		return -EINVAL;
+
+	cpu_np = of_get_child_by_name(link_np, "cpu");
+	codec_np = of_get_child_by_name(link_np, "codec");
+	if (!cpu_np || !codec_np) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = qcom_snd_parse_tdm_slot(cpu_np, cpu_cfg);
+	if (ret)
+		goto out;
+
+	ret = qcom_snd_parse_tdm_slot(codec_np, codec_cfg);
+out:
+	of_node_put(codec_np);
+	of_node_put(cpu_np);
+	of_node_put(link_np);
+
+	return ret;
+}
+
+int qcom_snd_get_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd,
+			       struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+			       struct qcom_snd_tdm_slot_cfg *codec_cfg)
+{
+	int ret;
+
+	ret = qcom_snd_parse_dai_tdm_slots(rtd, cpu_cfg, codec_cfg);
+	if (ret)
+		return ret;
+
+	return qcom_snd_normalize_tdm_slots(cpu_cfg, codec_cfg);
+}
+EXPORT_SYMBOL_GPL(qcom_snd_get_dai_tdm_slots);
+
+int qcom_snd_apply_dai_tdm_slots_cfg(struct snd_soc_pcm_runtime *rtd,
+				     const struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+				     const struct qcom_snd_tdm_slot_cfg *codec_cfg)
+{
+	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
+	struct snd_soc_dai *codec_dai;
+	int i;
+	int ret;
+
+	if (!cpu_cfg->slots)
+		return 0;
+
+	ret = snd_soc_dai_set_tdm_slot(cpu_dai, cpu_cfg->tx_mask, cpu_cfg->rx_mask,
+				       cpu_cfg->slots, cpu_cfg->slot_width);
+	if (ret)
+		return ret;
+
+	for_each_rtd_codec_dais(rtd, i, codec_dai) {
+		ret = snd_soc_dai_set_tdm_slot(codec_dai,
+					       codec_cfg->tx_mask,
+					       codec_cfg->rx_mask,
+					       codec_cfg->slots,
+					       codec_cfg->slot_width);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_snd_apply_dai_tdm_slots_cfg);
+
+int qcom_snd_apply_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd)
+{
+	struct qcom_snd_tdm_slot_cfg cpu_cfg;
+	struct qcom_snd_tdm_slot_cfg codec_cfg;
+	int ret;
+
+	ret = qcom_snd_get_dai_tdm_slots(rtd, &cpu_cfg, &codec_cfg);
+	if (ret)
+		return ret == -EINVAL ? 0 : ret;
+
+	return qcom_snd_apply_dai_tdm_slots_cfg(rtd, &cpu_cfg, &codec_cfg);
+}
+EXPORT_SYMBOL_GPL(qcom_snd_apply_dai_tdm_slots);
+
 int qcom_snd_parse_of(struct snd_soc_card *card)
 {
 	struct device *dev = card->dev;
diff --git a/sound/soc/qcom/common.h b/sound/soc/qcom/common.h
index ee6662885..02b24caec 100644
--- a/sound/soc/qcom/common.h
+++ b/sound/soc/qcom/common.h
@@ -9,7 +9,21 @@
 
 #define LPASS_MAX_PORT			(SENARY_MI2S_TX + 1)
 
+struct qcom_snd_tdm_slot_cfg {
+	unsigned int tx_mask;
+	unsigned int rx_mask;
+	unsigned int slots;
+	unsigned int slot_width;
+};
+
 int qcom_snd_parse_of(struct snd_soc_card *card);
+int qcom_snd_get_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd,
+			       struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+			       struct qcom_snd_tdm_slot_cfg *codec_cfg);
+int qcom_snd_apply_dai_tdm_slots_cfg(struct snd_soc_pcm_runtime *rtd,
+				     const struct qcom_snd_tdm_slot_cfg *cpu_cfg,
+				     const struct qcom_snd_tdm_slot_cfg *codec_cfg);
+int qcom_snd_apply_dai_tdm_slots(struct snd_soc_pcm_runtime *rtd);
 int qcom_snd_wcd_jack_setup(struct snd_soc_pcm_runtime *rtd,
 			    struct snd_soc_jack *jack, bool *jack_setup);
 int qcom_snd_dp_jack_setup(struct snd_soc_pcm_runtime *rtd,
-- 
2.34.1