From:   Prabhakar <prabhakar.csengg@gmail.com>
To:     Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Geert Uytterhoeven <geert+renesas@glider.be>,
        Magnus Damm <magnus.damm@gmail.com>,
        Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>
Cc:     alsa-devel@alsa-project.org, linux-renesas-soc@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Prabhakar <prabhakar.csengg@gmail.com>,
        Biju Das <biju.das.jz@bp.renesas.com>,
        Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Subject: [PATCH 2/4] ASoC: sh: rz-ssi: Update interrupt handling for half duplex channels
Date:   Fri, 17 Feb 2023 18:52:23 +0000
Message-Id: <20230217185225.43310-3-prabhakar.mahadev-lad.rj@bp.renesas.com>
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References: <20230217185225.43310-1-prabhakar.mahadev-lad.rj@bp.renesas.com>
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From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

For half duplex channels we dont have separate interrupts for Tx and Rx
instead we have single interrupt Rt (where the signal for Rx and Tx is
muxed). To handle such a case install a handler in case we have a dma_rt
interrupt specified in the DT for the PIO mode.

Note, for backward compatibility we check if the Rx and Tx interrupts
are present first instead of checking Rt interrupt.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Biju Das <biju.das.jz@bp.renesas.com>
---
 sound/soc/sh/rz-ssi.c | 63 ++++++++++++++++++++++++++++++-------------
 1 file changed, 44 insertions(+), 19 deletions(-)

diff --git a/sound/soc/sh/rz-ssi.c b/sound/soc/sh/rz-ssi.c
index 5d6bae33ae34..d502aa55c5a8 100644
--- a/sound/soc/sh/rz-ssi.c
+++ b/sound/soc/sh/rz-ssi.c
@@ -109,6 +109,7 @@ struct rz_ssi_priv {
 	int irq_int;
 	int irq_tx;
 	int irq_rx;
+	int irq_rt;
 
 	spinlock_t lock;
 
@@ -565,6 +566,17 @@ static irqreturn_t rz_ssi_interrupt(int irq, void *data)
 		rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
 	}
 
+	if (irq == ssi->irq_rt) {
+		struct snd_pcm_substream *substream = strm->substream;
+
+		if (rz_ssi_stream_is_play(ssi, substream)) {
+			strm->transfer(ssi, &ssi->playback);
+		} else {
+			strm->transfer(ssi, &ssi->capture);
+			rz_ssi_reg_mask_setl(ssi, SSIFSR, SSIFSR_RDF, 0);
+		}
+	}
+
 	return IRQ_HANDLED;
 }
 
@@ -993,26 +1005,39 @@ static int rz_ssi_probe(struct platform_device *pdev)
 	if (!rz_ssi_is_dma_enabled(ssi)) {
 		/* Tx and Rx interrupts (pio only) */
 		ssi->irq_tx = platform_get_irq_byname(pdev, "dma_tx");
-		if (ssi->irq_tx < 0)
-			return ssi->irq_tx;
-
-		ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
-				       &rz_ssi_interrupt, 0,
-				       dev_name(&pdev->dev), ssi);
-		if (ret < 0)
-			return dev_err_probe(&pdev->dev, ret,
-					     "irq request error (dma_tx)\n");
-
 		ssi->irq_rx = platform_get_irq_byname(pdev, "dma_rx");
-		if (ssi->irq_rx < 0)
-			return ssi->irq_rx;
-
-		ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
-				       &rz_ssi_interrupt, 0,
-				       dev_name(&pdev->dev), ssi);
-		if (ret < 0)
-			return dev_err_probe(&pdev->dev, ret,
-					     "irq request error (dma_rx)\n");
+		if (ssi->irq_tx == -ENXIO && ssi->irq_rx == -ENXIO) {
+			ssi->irq_rt = platform_get_irq_byname(pdev, "dma_rt");
+			if (ssi->irq_rt < 0)
+				return ssi->irq_rt;
+
+			ret = devm_request_irq(&pdev->dev, ssi->irq_rt,
+					       &rz_ssi_interrupt, 0,
+					       dev_name(&pdev->dev), ssi);
+			if (ret < 0)
+				return dev_err_probe(&pdev->dev, ret,
+						"irq request error (dma_tx)\n");
+		} else {
+			if (ssi->irq_tx < 0)
+				return ssi->irq_tx;
+
+			if (ssi->irq_rx < 0)
+				return ssi->irq_rx;
+
+			ret = devm_request_irq(&pdev->dev, ssi->irq_tx,
+					       &rz_ssi_interrupt, 0,
+					       dev_name(&pdev->dev), ssi);
+			if (ret < 0)
+				return dev_err_probe(&pdev->dev, ret,
+						"irq request error (dma_tx)\n");
+
+			ret = devm_request_irq(&pdev->dev, ssi->irq_rx,
+					       &rz_ssi_interrupt, 0,
+					       dev_name(&pdev->dev), ssi);
+			if (ret < 0)
+				return dev_err_probe(&pdev->dev, ret,
+						"irq request error (dma_rx)\n");
+		}
 	}
 
 	ssi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
-- 
2.25.1