From a957499bd437720d082d92657b7eb5cf5a62e893 Mon Sep 17 00:00:00 2001 From: Vladimir Oltean Date: Wed, 18 Mar 2020 02:15:54 +0200 Subject: spi: spi-fsl-dspi: Fix bits-per-word acceleration in DMA mode In DMA mode, dspi_setup_accel does not get called, which results in the dspi->oper_word_size variable (which is used by dspi_dma_xfer) to not be initialized properly. Because oper_word_size is zero, a few calculations end up being incorrect, and the DMA transfer eventually times out instead of sending anything on the wire. Set up native transfers (or 8-on-16 acceleration) using dspi_setup_accel for DMA mode too. Also take the opportunity and simplify the DMA buffer handling a little bit. Fixes: 6c1c26ecd9a3 ("spi: spi-fsl-dspi: Accelerate transfers using larger word size if possible") Signed-off-by: Vladimir Oltean Tested-by: Michael Walle Link: https://lore.kernel.org/r/20200318001603.9650-4-olteanv@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 86 +++++++++++++++++----------------------------- 1 file changed, 32 insertions(+), 54 deletions(-) (limited to 'drivers/spi') diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index be717776dd98..8f2b73cc6ed7 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -119,7 +119,6 @@ struct fsl_dspi_devtype_data { enum dspi_trans_mode trans_mode; u8 max_clock_factor; int fifo_size; - int dma_bufsize; }; enum { @@ -138,7 +137,6 @@ static const struct fsl_dspi_devtype_data devtype_data[] = { [VF610] = { .trans_mode = DSPI_DMA_MODE, .max_clock_factor = 2, - .dma_bufsize = 4096, .fifo_size = 4, }, [LS1021A] = { @@ -167,19 +165,16 @@ static const struct fsl_dspi_devtype_data devtype_data[] = { }, [LS2080A] = { .trans_mode = DSPI_DMA_MODE, - .dma_bufsize = 8, .max_clock_factor = 8, .fifo_size = 4, }, [LS2085A] = { .trans_mode = DSPI_DMA_MODE, - .dma_bufsize = 8, .max_clock_factor = 8, .fifo_size = 4, }, [LX2160A] = { .trans_mode = DSPI_DMA_MODE, - .dma_bufsize = 8, .max_clock_factor = 8, .fifo_size = 4, }, @@ -191,9 +186,6 @@ static const struct fsl_dspi_devtype_data devtype_data[] = { }; struct fsl_dspi_dma { - /* Length of transfer in words of dspi->fifo_size */ - u32 curr_xfer_len; - u32 *tx_dma_buf; struct dma_chan *chan_tx; dma_addr_t tx_dma_phys; @@ -352,7 +344,7 @@ static void dspi_rx_dma_callback(void *arg) int i; if (dspi->rx) { - for (i = 0; i < dma->curr_xfer_len; i++) + for (i = 0; i < dspi->words_in_flight; i++) dspi_push_rx(dspi, dspi->dma->rx_dma_buf[i]); } @@ -366,12 +358,12 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) int time_left; int i; - for (i = 0; i < dma->curr_xfer_len; i++) + for (i = 0; i < dspi->words_in_flight; i++) dspi->dma->tx_dma_buf[i] = dspi_pop_tx_pushr(dspi); dma->tx_desc = dmaengine_prep_slave_single(dma->chan_tx, dma->tx_dma_phys, - dma->curr_xfer_len * + dspi->words_in_flight * DMA_SLAVE_BUSWIDTH_4_BYTES, DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); @@ -389,7 +381,7 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) dma->rx_desc = dmaengine_prep_slave_single(dma->chan_rx, dma->rx_dma_phys, - dma->curr_xfer_len * + dspi->words_in_flight * DMA_SLAVE_BUSWIDTH_4_BYTES, DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); @@ -437,46 +429,42 @@ static int dspi_next_xfer_dma_submit(struct fsl_dspi *dspi) return 0; } +static void dspi_setup_accel(struct fsl_dspi *dspi); + static int dspi_dma_xfer(struct fsl_dspi *dspi) { struct spi_message *message = dspi->cur_msg; struct device *dev = &dspi->pdev->dev; - struct fsl_dspi_dma *dma = dspi->dma; - int curr_remaining_bytes; - int bytes_per_buffer; int ret = 0; - curr_remaining_bytes = dspi->len; - bytes_per_buffer = dspi->devtype_data->dma_bufsize / - dspi->devtype_data->fifo_size; - while (curr_remaining_bytes) { - /* Check if current transfer fits the DMA buffer */ - dma->curr_xfer_len = curr_remaining_bytes / - dspi->oper_word_size; - if (dma->curr_xfer_len > bytes_per_buffer) - dma->curr_xfer_len = bytes_per_buffer; + /* + * dspi->len gets decremented by dspi_pop_tx_pushr in + * dspi_next_xfer_dma_submit + */ + while (dspi->len) { + /* 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; + + message->actual_length += dspi->words_in_flight * + dspi->oper_word_size; ret = dspi_next_xfer_dma_submit(dspi); if (ret) { dev_err(dev, "DMA transfer failed\n"); - goto exit; - - } else { - const int len = dma->curr_xfer_len * - dspi->oper_word_size; - curr_remaining_bytes -= len; - message->actual_length += len; - if (curr_remaining_bytes < 0) - curr_remaining_bytes = 0; + break; } } -exit: return ret; } 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; @@ -501,16 +489,16 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) } dma->tx_dma_buf = dma_alloc_coherent(dma->chan_tx->device->dev, - dspi->devtype_data->dma_bufsize, - &dma->tx_dma_phys, GFP_KERNEL); + dma_bufsize, &dma->tx_dma_phys, + GFP_KERNEL); if (!dma->tx_dma_buf) { ret = -ENOMEM; goto err_tx_dma_buf; } dma->rx_dma_buf = dma_alloc_coherent(dma->chan_rx->device->dev, - dspi->devtype_data->dma_bufsize, - &dma->rx_dma_phys, GFP_KERNEL); + dma_bufsize, &dma->rx_dma_phys, + GFP_KERNEL); if (!dma->rx_dma_buf) { ret = -ENOMEM; goto err_rx_dma_buf; @@ -547,12 +535,10 @@ static int dspi_request_dma(struct fsl_dspi *dspi, phys_addr_t phy_addr) err_slave_config: dma_free_coherent(dma->chan_rx->device->dev, - dspi->devtype_data->dma_bufsize, - dma->rx_dma_buf, dma->rx_dma_phys); + dma_bufsize, dma->rx_dma_buf, dma->rx_dma_phys); err_rx_dma_buf: dma_free_coherent(dma->chan_tx->device->dev, - dspi->devtype_data->dma_bufsize, - dma->tx_dma_buf, dma->tx_dma_phys); + dma_bufsize, dma->tx_dma_buf, dma->tx_dma_phys); err_tx_dma_buf: dma_release_channel(dma->chan_tx); err_tx_channel: @@ -566,6 +552,7 @@ 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) @@ -573,15 +560,13 @@ static void dspi_release_dma(struct fsl_dspi *dspi) if (dma->chan_tx) { dma_unmap_single(dma->chan_tx->device->dev, dma->tx_dma_phys, - dspi->devtype_data->dma_bufsize, - DMA_TO_DEVICE); + dma_bufsize, DMA_TO_DEVICE); dma_release_channel(dma->chan_tx); } if (dma->chan_rx) { dma_unmap_single(dma->chan_rx->device->dev, dma->rx_dma_phys, - dspi->devtype_data->dma_bufsize, - DMA_FROM_DEVICE); + dma_bufsize, DMA_FROM_DEVICE); dma_release_channel(dma->chan_rx); } } @@ -833,7 +818,7 @@ no_accel: dspi->oper_word_size = DIV_ROUND_UP(dspi->oper_bits_per_word, 8); /* - * Update CTAR here (code is common for both EOQ and XSPI modes). + * Update CTAR here (code is common for EOQ, XSPI and DMA modes). * We will update CTARE in the portion specific to XSPI, when we * also know the preload value (DTCP). */ @@ -960,13 +945,6 @@ static int dspi_transfer_one_message(struct spi_controller *ctlr, regmap_update_bits(dspi->regmap, SPI_MCR, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF, SPI_MCR_CLR_TXF | SPI_MCR_CLR_RXF); - /* - * Static CTAR setup for modes that don't dynamically adjust it - * via dspi_setup_accel (aka for DMA) - */ - regmap_write(dspi->regmap, SPI_CTAR(0), - dspi->cur_chip->ctar_val | - SPI_FRAME_BITS(transfer->bits_per_word)); spi_take_timestamp_pre(dspi->ctlr, dspi->cur_transfer, dspi->progress, !dspi->irq); -- cgit