From ba9b28652c75b07383e267328f1759195d5430f7 Mon Sep 17 00:00:00 2001 From: Carlos Song Date: Wed, 3 Dec 2025 16:59:49 +0800 Subject: [PATCH] spi: imx: enable DMA mode for target operation 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 Reviewed-by: Frank Li Link: https://patch.msgid.link/20251203085949.2922166-7-carlos.song@nxp.com Signed-off-by: Mark Brown --- drivers/spi/spi-imx.c | 77 ++++++++++++++++++++++++++++++++----------- 1 file changed, 57 insertions(+), 20 deletions(-) diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index 04a492e7dbebf..69c288c8c7378 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -264,7 +264,13 @@ static bool spi_imx_can_dma(struct spi_controller *controller, struct spi_device if (!controller->dma_rx) return false; - if (spi_imx->target_mode) + /* + * Due to Freescale errata ERR003775 "eCSPI: Burst completion by Chip + * Select (SS) signal in Slave mode is not functional" burst size must + * be set exactly to the size of the transfer. This limit SPI transaction + * with maximum 2^12 bits. + */ + if (transfer->len > MX53_MAX_TRANSFER_BYTES && spi_imx->target_mode) return false; if (transfer->len < spi_imx->devtype_data->fifo_size) @@ -1763,23 +1769,51 @@ 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) || + READ_ONCE(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) || + READ_ONCE(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; @@ -1902,7 +1936,7 @@ dma_failure_no_start: 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; @@ -2108,7 +2142,7 @@ 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); /* @@ -2120,7 +2154,10 @@ 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; } -- 2.47.3