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Message-Id: <20230613191910.725049-1-fido_max@inbox.ru>
Date: Tue, 13 Jun 2023 22:19:08 +0300
From: Maxim Kochetkov <fido_max@...ox.ru>
To: alsa-devel@...a-project.org
Cc: Maxim Kochetkov <fido_max@...ox.ru>,
Liam Girdwood <lgirdwood@...il.com>,
Mark Brown <broonie@...nel.org>,
Jaroslav Kysela <perex@...ex.cz>,
Takashi Iwai <tiwai@...e.com>,
Charles Keepax <ckeepax@...nsource.cirrus.com>,
Uwe Kleine-König
<u.kleine-koenig@...gutronix.de>, linux-kernel@...r.kernel.org
Subject: [PATCH 1/1] ASoC: dwc: add DMA handshake control
DMA mode uses hardware handshake signals. DMACR register is used to enable
the DMA Controller interface operation. So add DMA enable/disable to
i2s_start()/i2s_stop() functions if using DMA mode.
Signed-off-by: Maxim Kochetkov <fido_max@...ox.ru>
---
sound/soc/dwc/dwc-i2s.c | 39 +++++++++++++++++++++++++++++++++++++--
sound/soc/dwc/local.h | 6 ++++++
2 files changed, 43 insertions(+), 2 deletions(-)
diff --git a/sound/soc/dwc/dwc-i2s.c b/sound/soc/dwc/dwc-i2s.c
index 9e7065dd854c..02b9894e99a7 100644
--- a/sound/soc/dwc/dwc-i2s.c
+++ b/sound/soc/dwc/dwc-i2s.c
@@ -150,19 +150,51 @@ static irqreturn_t i2s_irq_handler(int irq, void *dev_id)
return IRQ_NONE;
}
+static void i2s_enable_dma(struct dw_i2s_dev *dev, u32 stream)
+{
+ u32 dma_reg = i2s_read_reg(dev->i2s_base, I2S_DMACR);
+
+ /* Enable DMA handshake for stream */
+ if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+ dma_reg |= I2S_DMAEN_TXBLOCK;
+ else
+ dma_reg |= I2S_DMAEN_RXBLOCK;
+
+ i2s_write_reg(dev->i2s_base, I2S_DMACR, dma_reg);
+}
+
+static void i2s_disable_dma(struct dw_i2s_dev *dev, u32 stream)
+{
+ u32 dma_reg = i2s_read_reg(dev->i2s_base, I2S_DMACR);
+
+ /* Disable DMA handshake for stream */
+ if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ dma_reg &= ~I2S_DMAEN_TXBLOCK;
+ i2s_write_reg(dev->i2s_base, I2S_RTXDMA, 1);
+ } else {
+ dma_reg &= ~I2S_DMAEN_RXBLOCK;
+ i2s_write_reg(dev->i2s_base, I2S_RRXDMA, 1);
+ }
+ i2s_write_reg(dev->i2s_base, I2S_DMACR, dma_reg);
+}
+
static void i2s_start(struct dw_i2s_dev *dev,
struct snd_pcm_substream *substream)
{
struct i2s_clk_config_data *config = &dev->config;
i2s_write_reg(dev->i2s_base, IER, 1);
- i2s_enable_irqs(dev, substream->stream, config->chan_nr);
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
i2s_write_reg(dev->i2s_base, ITER, 1);
else
i2s_write_reg(dev->i2s_base, IRER, 1);
+ if (dev->use_pio)
+ i2s_enable_irqs(dev, substream->stream, config->chan_nr);
+ else
+ i2s_enable_dma(dev, substream->stream);
+
i2s_write_reg(dev->i2s_base, CER, 1);
}
@@ -176,7 +208,10 @@ static void i2s_stop(struct dw_i2s_dev *dev,
else
i2s_write_reg(dev->i2s_base, IRER, 0);
- i2s_disable_irqs(dev, substream->stream, 8);
+ if (dev->use_pio)
+ i2s_disable_irqs(dev, substream->stream, 8);
+ else
+ i2s_disable_dma(dev, substream->stream);
if (!dev->active) {
i2s_write_reg(dev->i2s_base, CER, 0);
diff --git a/sound/soc/dwc/local.h b/sound/soc/dwc/local.h
index d64bd4f8fd34..ba4e397099be 100644
--- a/sound/soc/dwc/local.h
+++ b/sound/soc/dwc/local.h
@@ -53,6 +53,12 @@
#define I2S_COMP_VERSION 0x01F8
#define I2S_COMP_TYPE 0x01FC
+#define I2S_RRXDMA 0x01C4
+#define I2S_RTXDMA 0x01CC
+#define I2S_DMACR 0x0200
+#define I2S_DMAEN_RXBLOCK (1 << 16)
+#define I2S_DMAEN_TXBLOCK (1 << 17)
+
/*
* Component parameter register fields - define the I2S block's
* configuration.
--
2.40.1
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