Unverified Commit a42e988b authored by Maxim Kochetkov's avatar Maxim Kochetkov Committed by Mark Brown
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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: default avatarMaxim Kochetkov <fido_max@inbox.ru>
Link: https://lore.kernel.org/r/20230613191910.725049-1-fido_max@inbox.ru


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 02474880

sound/soc/dwc/dwc-i2s.c

+37 −2
Original line number Diff line number Diff line
@@ -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);



	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);

sound/soc/dwc/local.h

+6 −0
Original line number Diff line number Diff line
@@ -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.