From f469138a77ac5ab685dfe15dfed7dccb9d5c33e5 Mon Sep 17 00:00:00 2001 From: Aaron Kling Date: Mon, 25 May 2026 01:47:44 -0500 Subject: [PATCH] spi: tegra210-quad: Allocate DMA memory for DMA engine When the SPI controllers are running in DMA mode, it is the DMA engine that performs the memory accesses rather than the SPI controller. Pass the DMA engine's struct device pointer to the DMA API to make sure the correct DMA operations are used. Suggested-by: Thierry Reding Signed-off-by: Aaron Kling Link: https://patch.msgid.link/20260525-tegra194-qspi-iommu-v2-1-a11c53f804b2@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-tegra210-quad.c | 29 ++++++++++++++++++----------- 1 file changed, 18 insertions(+), 11 deletions(-) diff --git a/drivers/spi/spi-tegra210-quad.c b/drivers/spi/spi-tegra210-quad.c index db28dd556484..588a929a9785 100644 --- a/drivers/spi/spi-tegra210-quad.c +++ b/drivers/spi/spi-tegra210-quad.c @@ -226,11 +226,13 @@ struct tegra_qspi { struct completion xfer_completion; struct spi_transfer *curr_xfer; + struct device *rx_dma_dev; struct dma_chan *rx_dma_chan; u32 *rx_dma_buf; dma_addr_t rx_dma_phys; struct dma_async_tx_descriptor *rx_dma_desc; + struct device *tx_dma_dev; struct dma_chan *tx_dma_chan; u32 *tx_dma_buf; dma_addr_t tx_dma_phys; @@ -574,15 +576,15 @@ static int tegra_qspi_dma_map_xfer(struct tegra_qspi *tqspi, struct spi_transfer len = DIV_ROUND_UP(tqspi->curr_dma_words * tqspi->bytes_per_word, 4) * 4; if (t->tx_buf) { - t->tx_dma = dma_map_single(tqspi->dev, (void *)tx_buf, len, DMA_TO_DEVICE); - if (dma_mapping_error(tqspi->dev, t->tx_dma)) + t->tx_dma = dma_map_single(tqspi->tx_dma_dev, (void *)tx_buf, len, DMA_TO_DEVICE); + if (dma_mapping_error(tqspi->tx_dma_dev, t->tx_dma)) return -ENOMEM; } if (t->rx_buf) { - t->rx_dma = dma_map_single(tqspi->dev, (void *)rx_buf, len, DMA_FROM_DEVICE); - if (dma_mapping_error(tqspi->dev, t->rx_dma)) { - dma_unmap_single(tqspi->dev, t->tx_dma, len, DMA_TO_DEVICE); + t->rx_dma = dma_map_single(tqspi->rx_dma_dev, (void *)rx_buf, len, DMA_FROM_DEVICE); + if (dma_mapping_error(tqspi->rx_dma_dev, t->rx_dma)) { + dma_unmap_single(tqspi->tx_dma_dev, t->tx_dma, len, DMA_TO_DEVICE); return -ENOMEM; } } @@ -597,9 +599,9 @@ static void tegra_qspi_dma_unmap_xfer(struct tegra_qspi *tqspi, struct spi_trans len = DIV_ROUND_UP(tqspi->curr_dma_words * tqspi->bytes_per_word, 4) * 4; if (t->tx_buf) - dma_unmap_single(tqspi->dev, t->tx_dma, len, DMA_TO_DEVICE); + dma_unmap_single(tqspi->tx_dma_dev, t->tx_dma, len, DMA_TO_DEVICE); if (t->rx_buf) - dma_unmap_single(tqspi->dev, t->rx_dma, len, DMA_FROM_DEVICE); + dma_unmap_single(tqspi->rx_dma_dev, t->rx_dma, len, DMA_FROM_DEVICE); } static int tegra_qspi_start_dma_based_transfer(struct tegra_qspi *tqspi, struct spi_transfer *t) @@ -745,7 +747,7 @@ static int tegra_qspi_start_cpu_based_transfer(struct tegra_qspi *qspi, struct s static void tegra_qspi_deinit_dma(struct tegra_qspi *tqspi) { if (tqspi->tx_dma_buf) { - dma_free_coherent(tqspi->dev, tqspi->dma_buf_size, + dma_free_coherent(tqspi->tx_dma_dev, tqspi->dma_buf_size, tqspi->tx_dma_buf, tqspi->tx_dma_phys); tqspi->tx_dma_buf = NULL; } @@ -756,7 +758,7 @@ static void tegra_qspi_deinit_dma(struct tegra_qspi *tqspi) } if (tqspi->rx_dma_buf) { - dma_free_coherent(tqspi->dev, tqspi->dma_buf_size, + dma_free_coherent(tqspi->rx_dma_dev, tqspi->dma_buf_size, tqspi->rx_dma_buf, tqspi->rx_dma_phys); tqspi->rx_dma_buf = NULL; } @@ -782,6 +784,7 @@ static int tegra_qspi_init_dma(struct tegra_qspi *tqspi) } tqspi->rx_dma_chan = dma_chan; + tqspi->rx_dma_dev = dmaengine_get_dma_device(tqspi->rx_dma_chan); dma_chan = dma_request_chan(tqspi->dev, "tx"); if (IS_ERR(dma_chan)) { @@ -790,15 +793,19 @@ static int tegra_qspi_init_dma(struct tegra_qspi *tqspi) } tqspi->tx_dma_chan = dma_chan; + tqspi->tx_dma_dev = dmaengine_get_dma_device(tqspi->tx_dma_chan); } else { if (!device_iommu_mapped(tqspi->dev)) { dev_warn(tqspi->dev, "IOMMU not enabled in device-tree, falling back to PIO mode\n"); return 0; } + + tqspi->rx_dma_dev = tqspi->dev; + tqspi->tx_dma_dev = tqspi->dev; } - dma_buf = dma_alloc_coherent(tqspi->dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL); + dma_buf = dma_alloc_coherent(tqspi->rx_dma_dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL); if (!dma_buf) { err = -ENOMEM; goto err_out; @@ -807,7 +814,7 @@ static int tegra_qspi_init_dma(struct tegra_qspi *tqspi) tqspi->rx_dma_buf = dma_buf; tqspi->rx_dma_phys = dma_phys; - dma_buf = dma_alloc_coherent(tqspi->dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL); + dma_buf = dma_alloc_coherent(tqspi->tx_dma_dev, tqspi->dma_buf_size, &dma_phys, GFP_KERNEL); if (!dma_buf) { err = -ENOMEM; goto err_out;