ASoC: simple-card: Add tdm slot mask support to simple-card

Adds DT binding for explicitly choosing a tdm mask for DAI and uses it
in simple-card. The API for snd_soc_of_parse_tdm_slot() has also been
changed.

Signed-off-by: Jyri Sarha <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

Documentation/devicetree/bindings/sound/tdm-slot.txt

···
 
 TDM slot properties:
 dai-tdm-slot-num : Number of slots in use.
-dai-tdm-slot-width :  Width in bits for each slot.
+dai-tdm-slot-width : Width in bits for each slot.
+dai-tdm-slot-tx-mask : Transmit direction slot mask, optional
+dai-tdm-slot-rx-mask : Receive direction slot mask, optional
 
 For instance:
 	dai-tdm-slot-num = <2>;
 	dai-tdm-slot-width = <8>;
+	dai-tdm-slot-tx-mask = <0 1>;
+	dai-tdm-slot-rx-mask = <1 0>;
 
 And for each spcified driver, there could be one .of_xlate_tdm_slot_mask()
 to specify a explicit mapping of the channels and the slots. If it's absent
···
 For snd_soc_of_xlate_tdm_slot_mask(), the tx and rx masks will use a 1 bit
 for an active slot as default, and the default active bits are at the LSB of
 the masks.
+
+The explicit masks are given as array of integers, where the first
+number presents bit-0 (LSB), second presents bit-1, etc. Any non zero
+number is considered 1 and 0 is 0. snd_soc_of_xlate_tdm_slot_mask()
+does not do anything, if either mask is set non zero value.

include/sound/simple_card.h

···
 	unsigned int sysclk;
 	int slots;
 	int slot_width;
+	unsigned int tx_slot_mask;
+	unsigned int rx_slot_mask;
 	struct clk *clk;
 };
 

include/sound/soc.h

···
 int snd_soc_of_parse_audio_simple_widgets(struct snd_soc_card *card,
 					  const char *propname);
 int snd_soc_of_parse_tdm_slot(struct device_node *np,
+			      unsigned int *tx_mask,
+			      unsigned int *rx_mask,
 			      unsigned int *slots,
 			      unsigned int *slot_width);
 void snd_soc_of_parse_audio_prefix(struct snd_soc_card *card,

sound/soc/generic/simple-card.c

···
 	}
 
 	if (set->slots) {
-		ret = snd_soc_dai_set_tdm_slot(dai, 0, 0,
+		ret = snd_soc_dai_set_tdm_slot(dai,
+					       set->tx_slot_mask,
+					       set->rx_slot_mask,
 						set->slots,
 						set->slot_width);
 		if (ret && ret != -ENOTSUPP) {
···
 		return ret;
 
 	/* Parse TDM slot */
-	ret = snd_soc_of_parse_tdm_slot(np, &dai->slots, &dai->slot_width);
+	ret = snd_soc_of_parse_tdm_slot(np, &dai->tx_slot_mask,
+					&dai->rx_slot_mask,
+					&dai->slots, &dai->slot_width);
 	if (ret)
 		return ret;
 

sound/soc/soc-core.c

···
 }
 EXPORT_SYMBOL_GPL(snd_soc_of_parse_audio_simple_widgets);
 
+static int snd_soc_of_get_slot_mask(struct device_node *np,
+				    const char *prop_name,
+				    unsigned int *mask)
+{
+	u32 val;
+	const u32 *of_slot_mask = of_get_property(np, prop_name, &val);
+	int i;
+
+	if (!of_slot_mask)
+		return 0;
+	val /= sizeof(u32);
+	for (i = 0; i < val; i++)
+		if (be32_to_cpup(&of_slot_mask[i]))
+			*mask |= (1 << i);
+
+	return val;
+}
+
 int snd_soc_of_parse_tdm_slot(struct device_node *np,
+			      unsigned int *tx_mask,
+			      unsigned int *rx_mask,
 			      unsigned int *slots,
 			      unsigned int *slot_width)
 {
 	u32 val;
 	int ret;
+
+	if (tx_mask)
+		snd_soc_of_get_slot_mask(np, "dai-tdm-slot-tx-mask", tx_mask);
+	if (rx_mask)
+		snd_soc_of_get_slot_mask(np, "dai-tdm-slot-rx-mask", rx_mask);
 
 	if (of_property_read_bool(np, "dai-tdm-slot-num")) {
 		ret = of_property_read_u32(np, "dai-tdm-slot-num", &val);