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[PATCH 6/6] spi: imx: enable DMA mode for target operation

Carlos Song posted 6 patches 6 days, 13 hours ago
[PATCH 6/6] spi: imx: enable DMA mode for target operation
Posted by Carlos Song 6 days, 13 hours ago 
Enable DMA mode for SPI IMX in target mode.
Disable the word delay feature for target mode, because target mode should
always keep high performance to make sure it can follow the master. Target
mode continues to operate in dynamic burst mode.

Signed-off-by: Carlos Song <carlos.song@nxp.com>
---
 drivers/spi/spi-imx.c | 78 +++++++++++++++++++++++++++++++------------
 1 file changed, 56 insertions(+), 22 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index f02a47fbba8a..16b7d2f45012 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -264,9 +264,6 @@ static bool spi_imx_can_dma(struct spi_controller *controller, struct spi_device
 	if (!controller->dma_rx)
 		return false;
 
-	if (spi_imx->target_mode)
-		return false;
-
 	if (transfer->len < spi_imx->devtype_data->fifo_size)
 		return false;
 
@@ -1756,23 +1753,51 @@ static int spi_imx_dma_submit(struct spi_imx_data *spi_imx,
 
 	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
 
-	/* Wait SDMA to finish the data transfer.*/
-	time_left = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
-						transfer_timeout);
-	if (!time_left) {
-		dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
-		dmaengine_terminate_all(controller->dma_tx);
-		dmaengine_terminate_all(controller->dma_rx);
-		return -ETIMEDOUT;
-	}
+	if (!spi_imx->target_mode) {
+		/* Wait SDMA to finish the data transfer.*/
+		time_left = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
+							transfer_timeout);
+		if (!time_left) {
+			dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
+			dmaengine_terminate_all(controller->dma_tx);
+			dmaengine_terminate_all(controller->dma_rx);
+			return -ETIMEDOUT;
+		}
 
-	time_left = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
-						transfer_timeout);
-	if (!time_left) {
-		dev_err(&controller->dev, "I/O Error in DMA RX\n");
-		spi_imx->devtype_data->reset(spi_imx);
-		dmaengine_terminate_all(controller->dma_rx);
-		return -ETIMEDOUT;
+		time_left = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
+							transfer_timeout);
+		if (!time_left) {
+			dev_err(&controller->dev, "I/O Error in DMA RX\n");
+			spi_imx->devtype_data->reset(spi_imx);
+			dmaengine_terminate_all(controller->dma_rx);
+			return -ETIMEDOUT;
+		}
+	} else {
+		spi_imx->target_aborted = false;
+
+		if (wait_for_completion_interruptible(&spi_imx->dma_tx_completion) ||
+		    spi_imx->target_aborted) {
+			dev_dbg(spi_imx->dev, "I/O Error in DMA TX interrupted\n");
+			dmaengine_terminate_all(controller->dma_tx);
+			dmaengine_terminate_all(controller->dma_rx);
+			return -EINTR;
+		}
+
+		if (wait_for_completion_interruptible(&spi_imx->dma_rx_completion) ||
+		    spi_imx->target_aborted) {
+			dev_dbg(spi_imx->dev, "I/O Error in DMA RX interrupted\n");
+			dmaengine_terminate_all(controller->dma_rx);
+			return -EINTR;
+		}
+
+		/*
+		 * ECSPI has a HW issue when works in Target mode, after 64 words
+		 * writtern to TXFIFO, even TXFIFO becomes empty, ECSPI_TXDATA keeps
+		 * shift out the last word data, so we have to disable ECSPI when in
+		 * target mode after the transfer completes.
+		 */
+		if (spi_imx->devtype_data->disable)
+			spi_imx->devtype_data->disable(spi_imx);
 	}
 
 	return 0;
@@ -1895,10 +1920,16 @@ static int spi_imx_dma_package_transfer(struct spi_imx_data *spi_imx,
 static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 				struct spi_transfer *transfer)
 {
-	bool word_delay = transfer->word_delay.value != 0;
+	bool word_delay = transfer->word_delay.value != 0 && !spi_imx->target_mode;
 	int ret;
 	int i;
 
+	if (transfer->len > MX53_MAX_TRANSFER_BYTES && spi_imx->target_mode) {
+		dev_err(spi_imx->dev, "Transaction too big, max size is %d bytes\n",
+			MX53_MAX_TRANSFER_BYTES);
+		return -EMSGSIZE;
+	}
+
 	ret = spi_imx_dma_data_prepare(spi_imx, transfer, word_delay);
 	if (ret < 0) {
 		transfer->error |= SPI_TRANS_FAIL_NO_START;
@@ -2104,7 +2135,7 @@ static int spi_imx_transfer_one(struct spi_controller *controller,
 	while (spi_imx->devtype_data->rx_available(spi_imx))
 		readl(spi_imx->base + MXC_CSPIRXDATA);
 
-	if (spi_imx->target_mode)
+	if (spi_imx->target_mode && !spi_imx->usedma)
 		return spi_imx_pio_transfer_target(spi, transfer);
 
 	/*
@@ -2116,7 +2147,10 @@ static int spi_imx_transfer_one(struct spi_controller *controller,
 		ret = spi_imx_dma_transfer(spi_imx, transfer);
 		if (transfer->error & SPI_TRANS_FAIL_NO_START) {
 			spi_imx->usedma = false;
-			return spi_imx_pio_transfer(spi, transfer);
+			if (spi_imx->target_mode)
+				return spi_imx_pio_transfer_target(spi, transfer);
+			else
+				return spi_imx_pio_transfer(spi, transfer);
 		}
 		return ret;
 	}
-- 
2.34.1
Re: [PATCH 6/6] spi: imx: enable DMA mode for target operation
Posted by Marc Kleine-Budde 5 days, 11 hours ago 
On 25.11.2025 18:06:18, Carlos Song wrote:
> @@ -1895,10 +1920,16 @@ static int spi_imx_dma_package_transfer(struct spi_imx_data *spi_imx,
>  static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
>  				struct spi_transfer *transfer)
>  {
> -	bool word_delay = transfer->word_delay.value != 0;
> +	bool word_delay = transfer->word_delay.value != 0 && !spi_imx->target_mode;
>  	int ret;
>  	int i;
>
> +	if (transfer->len > MX53_MAX_TRANSFER_BYTES && spi_imx->target_mode) {
> +		dev_err(spi_imx->dev, "Transaction too big, max size is %d bytes\n",
> +			MX53_MAX_TRANSFER_BYTES);
> +		return -EMSGSIZE;
> +	}

If there is this limitation, this check should go into
spi_imx_can_dma().

Marc

-- 
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Re: [PATCH 6/6] spi: imx: enable DMA mode for target operation
Posted by Frank Li 6 days, 7 hours ago 
On Tue, Nov 25, 2025 at 06:06:18PM +0800, Carlos Song wrote:
> Enable DMA mode for SPI IMX in target mode.
> Disable the word delay feature for target mode, because target mode should
> always keep high performance to make sure it can follow the master. Target
> mode continues to operate in dynamic burst mode.

If two paragraph, need extra empty line. If one parapraph, move to previous
line.

>
> Signed-off-by: Carlos Song <carlos.song@nxp.com>
> ---
>  drivers/spi/spi-imx.c | 78 +++++++++++++++++++++++++++++++------------
>  1 file changed, 56 insertions(+), 22 deletions(-)
>
...
>
> @@ -1756,23 +1753,51 @@ static int spi_imx_dma_submit(struct spi_imx_data *spi_imx,
>
>  	transfer_timeout = spi_imx_calculate_timeout(spi_imx, transfer->len);
>
> -	/* Wait SDMA to finish the data transfer.*/
> -	time_left = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
> -						transfer_timeout);
> -	if (!time_left) {
> -		dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
> -		dmaengine_terminate_all(controller->dma_tx);
> -		dmaengine_terminate_all(controller->dma_rx);
> -		return -ETIMEDOUT;
> -	}
> +	if (!spi_imx->target_mode) {
> +		/* Wait SDMA to finish the data transfer.*/
> +		time_left = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
> +							transfer_timeout);
> +		if (!time_left) {
> +			dev_err(spi_imx->dev, "I/O Error in DMA TX\n");
> +			dmaengine_terminate_all(controller->dma_tx);
> +			dmaengine_terminate_all(controller->dma_rx);
> +			return -ETIMEDOUT;
> +		}
>
> -	time_left = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
> -						transfer_timeout);
> -	if (!time_left) {
> -		dev_err(&controller->dev, "I/O Error in DMA RX\n");
> -		spi_imx->devtype_data->reset(spi_imx);
> -		dmaengine_terminate_all(controller->dma_rx);
> -		return -ETIMEDOUT;
> +		time_left = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
> +							transfer_timeout);
> +		if (!time_left) {
> +			dev_err(&controller->dev, "I/O Error in DMA RX\n");
> +			spi_imx->devtype_data->reset(spi_imx);
> +			dmaengine_terminate_all(controller->dma_rx);
> +			return -ETIMEDOUT;
> +		}
> +	} else {
> +		spi_imx->target_aborted = false;
> +
> +		if (wait_for_completion_interruptible(&spi_imx->dma_tx_completion) ||
> +		    spi_imx->target_aborted) {

Suppose somewhere set target_aborted to true. I think here should use
READ_ONCE() to make sure read from memory.

Not sure why here use wait_for_completion_interruptible() but at master
mode use wait_for_completion_timeout().

> +			dev_dbg(spi_imx->dev, "I/O Error in DMA TX interrupted\n");
> +			dmaengine_terminate_all(controller->dma_tx);
> +			dmaengine_terminate_all(controller->dma_rx);
> +			return -EINTR;
> +		}
> +
> +		if (wait_for_completion_interruptible(&spi_imx->dma_rx_completion) ||
> +		    spi_imx->target_aborted) {
> +			dev_dbg(spi_imx->dev, "I/O Error in DMA RX interrupted\n");
> +			dmaengine_terminate_all(controller->dma_rx);
> +			return -EINTR;
> +		}
> +
> +		/*
> +		 * ECSPI has a HW issue when works in Target mode, after 64 words
> +		 * writtern to TXFIFO, even TXFIFO becomes empty, ECSPI_TXDATA keeps
> +		 * shift out the last word data, so we have to disable ECSPI when in
> +		 * target mode after the transfer completes.
> +		 */
> +		if (spi_imx->devtype_data->disable)
> +			spi_imx->devtype_data->disable(spi_imx);
>  	}
>
>  	return 0;
> @@ -1895,10 +1920,16 @@ static int spi_imx_dma_package_transfer(struct spi_imx_data *spi_imx,
>  static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
>  				struct spi_transfer *transfer)
>  {
> -	bool word_delay = transfer->word_delay.value != 0;
> +	bool word_delay = transfer->word_delay.value != 0 && !spi_imx->target_mode;
>  	int ret;
>  	int i;
>
> +	if (transfer->len > MX53_MAX_TRANSFER_BYTES && spi_imx->target_mode) {

why only target have len limiation?

Frank
> +		dev_err(spi_imx->dev, "Transaction too big, max size is %d bytes\n",
> +			MX53_MAX_TRANSFER_BYTES);
> +		return -EMSGSIZE;
> +	}
> +
>  	ret = spi_imx_dma_data_prepare(spi_imx, transfer, word_delay);
>  	if (ret < 0) {
>  		transfer->error |= SPI_TRANS_FAIL_NO_START;
> @@ -2104,7 +2135,7 @@ static int spi_imx_transfer_one(struct spi_controller *controller,
>  	while (spi_imx->devtype_data->rx_available(spi_imx))
>  		readl(spi_imx->base + MXC_CSPIRXDATA);
>
> -	if (spi_imx->target_mode)
> +	if (spi_imx->target_mode && !spi_imx->usedma)
>  		return spi_imx_pio_transfer_target(spi, transfer);
>
>  	/*
> @@ -2116,7 +2147,10 @@ static int spi_imx_transfer_one(struct spi_controller *controller,
>  		ret = spi_imx_dma_transfer(spi_imx, transfer);
>  		if (transfer->error & SPI_TRANS_FAIL_NO_START) {
>  			spi_imx->usedma = false;
> -			return spi_imx_pio_transfer(spi, transfer);
> +			if (spi_imx->target_mode)
> +				return spi_imx_pio_transfer_target(spi, transfer);
> +			else
> +				return spi_imx_pio_transfer(spi, transfer);
>  		}
>  		return ret;
>  	}
> --
> 2.34.1
>

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