ASoC: mchp-i2s-mcc: Add FIFOs support

I2S-MCC found on SAMA7G5 includes 2 FIFOs (capture and playback). When
FIFOs are enabled, bits I2SMCC_ISRA.TXLRDYx and I2SMCC_ISRA.TXRRDYx must
not be used. Bits I2SMCC_ISRB.TXFFRDY and I2SMCC_ISRB.RXFFRDY must be used
instead.
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20210301170905.835091-7-codrin.ciubotariu@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/mchp-i2s-mcc.c

@@ -176,7 +176,7 @@
  */
 #define MCHP_I2SMCC_MRB_CRAMODE_REGULAR		(1 << 0)
 
-#define MCHP_I2SMCC_MRB_FIFOEN			BIT(1)
+#define MCHP_I2SMCC_MRB_FIFOEN			BIT(4)
 
 #define MCHP_I2SMCC_MRB_DMACHUNK_MASK		GENMASK(9, 8)
 #define MCHP_I2SMCC_MRB_DMACHUNK(no_words) \
@@ -230,6 +230,7 @@ static const struct regmap_config mchp_i2s_mcc_regmap_config = {
 
 struct mchp_i2s_mcc_soc_data {
 	unsigned int	data_pin_pair_num;
+	bool		has_fifo;
 };
 
 struct mchp_i2s_mcc_dev {
@@ -257,7 +258,7 @@ struct mchp_i2s_mcc_dev {
 static irqreturn_t mchp_i2s_mcc_interrupt(int irq, void *dev_id)
 {
 	struct mchp_i2s_mcc_dev *dev = dev_id;
-	u32 sra, imra, srb, imrb, pendinga, pendingb, idra = 0;
+	u32 sra, imra, srb, imrb, pendinga, pendingb, idra = 0, idrb = 0;
 	irqreturn_t ret = IRQ_NONE;
 
 	regmap_read(dev->regmap, MCHP_I2SMCC_IMRA, &imra);
@@ -275,23 +276,35 @@ static irqreturn_t mchp_i2s_mcc_interrupt(int irq, void *dev_id)
 	 * Tx/Rx ready interrupts are enabled when stopping only, to assure
 	 * availability and to disable clocks if necessary
 	 */
+	if (dev->soc->has_fifo) {
+		idrb |= pendingb & (MCHP_I2SMCC_INT_TXFFRDY |
+				    MCHP_I2SMCC_INT_RXFFRDY);
+	} else {
 		idra |= pendinga & (MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels) |
 				    MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels));
-	if (idra)
+	}
+	if (idra || idrb)
 		ret = IRQ_HANDLED;
 
-	if ((imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) &&
+	if ((!dev->soc->has_fifo &&
+	     (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) &&
 	     (imra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels)) ==
-	    (idra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels))) {
+	     (idra & MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels))) ||
+	    (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_TXFFRDY)) {
 		dev->tx_rdy = 1;
 		wake_up_interruptible(&dev->wq_txrdy);
 	}
-	if ((imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) &&
+	if ((!dev->soc->has_fifo &&
+	     (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) &&
 	     (imra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels)) ==
-	    (idra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels))) {
+	     (idra & MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels))) ||
+	    (dev->soc->has_fifo && imrb & MCHP_I2SMCC_INT_RXFFRDY)) {
 		dev->rx_rdy = 1;
 		wake_up_interruptible(&dev->wq_rxrdy);
 	}
+	if (dev->soc->has_fifo)
+		regmap_write(dev->regmap, MCHP_I2SMCC_IDRB, idrb);
+	else
 		regmap_write(dev->regmap, MCHP_I2SMCC_IDRA, idra);
 
 	return ret;
@@ -664,6 +677,10 @@ static int mchp_i2s_mcc_hw_params(struct snd_pcm_substream *substream,
 		}
 	}
 
+	/* enable FIFO if available */
+	if (dev->soc->has_fifo)
+		mrb |= MCHP_I2SMCC_MRB_FIFOEN;
+
 	/*
 	 * If we are already running, the wanted setup must be
 	 * the same with the one that's currently ongoing
@@ -726,8 +743,13 @@ static int mchp_i2s_mcc_hw_free(struct snd_pcm_substream *substream,
 		if (err == 0) {
 			dev_warn_once(dev->dev,
 				      "Timeout waiting for Tx ready\n");
+			if (dev->soc->has_fifo)
+				regmap_write(dev->regmap, MCHP_I2SMCC_IDRB,
+					     MCHP_I2SMCC_INT_TXFFRDY);
+			else
 				regmap_write(dev->regmap, MCHP_I2SMCC_IDRA,
 					     MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels));
+
 			dev->tx_rdy = 1;
 		}
 	} else {
@@ -737,6 +759,10 @@ static int mchp_i2s_mcc_hw_free(struct snd_pcm_substream *substream,
 		if (err == 0) {
 			dev_warn_once(dev->dev,
 				      "Timeout waiting for Rx ready\n");
+			if (dev->soc->has_fifo)
+				regmap_write(dev->regmap, MCHP_I2SMCC_IDRB,
+					     MCHP_I2SMCC_INT_RXFFRDY);
+			else
 				regmap_write(dev->regmap, MCHP_I2SMCC_IDRA,
 					     MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels));
 			dev->rx_rdy = 1;
@@ -765,7 +791,7 @@ static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
 	struct mchp_i2s_mcc_dev *dev = snd_soc_dai_get_drvdata(dai);
 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
 	u32 cr = 0;
-	u32 iera = 0;
+	u32 iera = 0, ierb = 0;
 	u32 sr;
 	int err;
 
@@ -789,6 +815,9 @@ static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
 			 * Enable Tx Ready interrupts on all channels
 			 * to assure all data is sent
 			 */
+			if (dev->soc->has_fifo)
+				ierb = MCHP_I2SMCC_INT_TXFFRDY;
+			else
 				iera = MCHP_I2SMCC_INT_TXRDY_MASK(dev->channels);
 		} else if (!is_playback && (sr & MCHP_I2SMCC_SR_RXEN)) {
 			cr = MCHP_I2SMCC_CR_RXDIS;
@@ -797,6 +826,9 @@ static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
 			 * Enable Rx Ready interrupts on all channels
 			 * to assure all data is received
 			 */
+			if (dev->soc->has_fifo)
+				ierb = MCHP_I2SMCC_INT_RXFFRDY;
+			else
 				iera = MCHP_I2SMCC_INT_RXRDY_MASK(dev->channels);
 		}
 		break;
@@ -815,6 +847,9 @@ static int mchp_i2s_mcc_trigger(struct snd_pcm_substream *substream, int cmd,
 		}
 	}
 
+	if (dev->soc->has_fifo)
+		regmap_write(dev->regmap, MCHP_I2SMCC_IERB, ierb);
+	else
 		regmap_write(dev->regmap, MCHP_I2SMCC_IERA, iera);
 	regmap_write(dev->regmap, MCHP_I2SMCC_CR, cr);
 
@@ -903,6 +938,7 @@ static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sam9x60 = {
 
 static struct mchp_i2s_mcc_soc_data mchp_i2s_mcc_sama7g5 = {
 	.data_pin_pair_num = 4,
+	.has_fifo = true,
 };
 
 static const struct of_device_id mchp_i2s_mcc_dt_ids[] = {