diff options
| -rw-r--r-- | drivers/spi/spi-fsl-dspi.c | 41 |
1 files changed, 30 insertions, 11 deletions
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 81d1e4470f94..6bf87ef01c13 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -331,6 +331,8 @@ struct fsl_dspi_dma { dma_addr_t rx_dma_phys; struct completion cmd_rx_complete; struct dma_async_tx_descriptor *rx_desc; + + size_t bufsize; }; struct fsl_dspi { @@ -493,6 +495,24 @@ static u32 dspi_pop_tx_pushr(struct fsl_dspi *dspi) return cmd << 16 | data; } +static size_t dspi_dma_max_datawords(struct fsl_dspi *dspi) +{ + /* + * Transfers look like one of these, so we always use a full DMA word + * regardless of SPI word size: + * + * 31 16 15 0 + * ----------------------------------------- + * | CONTROL WORD | 16-bit DATA | + * ----------------------------------------- + * or + * ----------------------------------------- + * | CONTROL WORD | UNUSED | 8-bit DATA | + * ----------------------------------------- + */ + return dspi->dma->bufsize / DMA_SLAVE_BUSWIDTH_4_BYTES; +} + static size_t dspi_dma_transfer_size(struct fsl_dspi *dspi) { return dspi->words_in_flight * DMA_SLAVE_BUSWIDTH_4_BYTES; @@ -620,9 +640,8 @@ static void dspi_dma_xfer(struct fsl_dspi *dspi) /* Figure out operational bits-per-word for this chunk */ dspi_setup_accel(dspi); - dspi->words_in_flight = dspi->len / dspi->oper_word_size; - if (dspi->words_in_flight > dspi->devtype_data->fifo_size) - dspi->words_in_flight = dspi->devtype_data->fifo_size; + dspi->words_in_flight = min(dspi->len / dspi->oper_word_size, + dspi_dma_max_datawords(dspi)); message->actual_length += dspi->words_in_flight * dspi->oper_word_size; @@ -637,7 +656,6 @@ static void dspi_dma_xfer(struct fsl_dspi *dspi) static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) { - int dma_bufsize = dspi->devtype_data->fifo_size * 2; struct device *dev = &dspi->pdev->dev; struct dma_slave_config cfg; struct fsl_dspi_dma *dma; @@ -657,8 +675,10 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) goto err_tx_channel; } + dma->bufsize = PAGE_SIZE; + dma->tx_dma_buf = dma_alloc_noncoherent(dma->chan_tx->device->dev, - dma_bufsize, &dma->tx_dma_phys, + dma->bufsize, &dma->tx_dma_phys, DMA_TO_DEVICE, GFP_KERNEL); if (!dma->tx_dma_buf) { ret = -ENOMEM; @@ -666,7 +686,7 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) } dma->rx_dma_buf = dma_alloc_noncoherent(dma->chan_rx->device->dev, - dma_bufsize, &dma->rx_dma_phys, + dma->bufsize, &dma->rx_dma_phys, DMA_FROM_DEVICE, GFP_KERNEL); if (!dma->rx_dma_buf) { ret = -ENOMEM; @@ -702,11 +722,11 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) return 0; err_slave_config: - dma_free_noncoherent(dma->chan_rx->device->dev, dma_bufsize, + dma_free_noncoherent(dma->chan_rx->device->dev, dma->bufsize, dma->rx_dma_buf, dma->rx_dma_phys, DMA_FROM_DEVICE); err_rx_dma_buf: - dma_free_noncoherent(dma->chan_tx->device->dev, dma_bufsize, + dma_free_noncoherent(dma->chan_tx->device->dev, dma->bufsize, dma->tx_dma_buf, dma->tx_dma_phys, DMA_TO_DEVICE); err_tx_dma_buf: dma_release_channel(dma->chan_tx); @@ -721,21 +741,20 @@ err_tx_channel: static void dspi_release_dma(struct fsl_dspi *dspi) { - int dma_bufsize = dspi->devtype_data->fifo_size * 2; struct fsl_dspi_dma *dma = dspi->dma; if (!dma) return; if (dma->chan_tx) { - dma_free_noncoherent(dma->chan_tx->device->dev, dma_bufsize, + dma_free_noncoherent(dma->chan_tx->device->dev, dma->bufsize, dma->tx_dma_buf, dma->tx_dma_phys, DMA_TO_DEVICE); dma_release_channel(dma->chan_tx); } if (dma->chan_rx) { - dma_free_noncoherent(dma->chan_rx->device->dev, dma_bufsize, + dma_free_noncoherent(dma->chan_rx->device->dev, dma->bufsize, dma->rx_dma_buf, dma->rx_dma_phys, DMA_FROM_DEVICE); dma_release_channel(dma->chan_rx); |