From 04242ca4e8917999ac2bbc3d2b10409661f60272 Mon Sep 17 00:00:00 2001 From: Cyrille Pitchen Date: Thu, 24 Nov 2016 12:24:59 +0100 Subject: [PATCH] spi: atmel: Use SPI core DMA mapping framework Use the SPI core DMA mapping framework instead of our own in case of DMA support. PDC support is not converted to this framework. The driver is now able to transfer a complete sg list through DMA. This eventually fix an issue with vmalloc'ed DMA memory that is provided for example by UBI/UBIFS layers. Signed-off-by: Cyrille Pitchen [nicolas.ferre@atmel.com: restrict the use to non-PDC DMA] Signed-off-by: Nicolas Ferre Signed-off-by: Mark Brown --- drivers/spi/spi-atmel.c | 57 ++++++++++++++++++----------------------- 1 file changed, 25 insertions(+), 32 deletions(-) diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c index 8f20d4f75e4a..7e03e221d307 100644 --- a/drivers/spi/spi-atmel.c +++ b/drivers/spi/spi-atmel.c @@ -268,8 +268,6 @@ struct atmel_spi_dma { struct dma_chan *chan_rx; struct dma_chan *chan_tx; - struct scatterlist sgrx; - struct scatterlist sgtx; struct dma_async_tx_descriptor *data_desc_rx; struct dma_async_tx_descriptor *data_desc_tx; @@ -453,6 +451,15 @@ static inline bool atmel_spi_use_dma(struct atmel_spi *as, return as->use_dma && xfer->len >= DMA_MIN_BYTES; } +static bool atmel_spi_can_dma(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *xfer) +{ + struct atmel_spi *as = spi_master_get_devdata(master); + + return atmel_spi_use_dma(as, xfer); +} + static int atmel_spi_dma_slave_config(struct atmel_spi *as, struct dma_slave_config *slave_config, u8 bits_per_word) @@ -720,7 +727,6 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, struct dma_async_tx_descriptor *txdesc; struct dma_slave_config slave_config; dma_cookie_t cookie; - u32 len = *plen; dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma_submit\n"); @@ -731,34 +737,22 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, /* release lock for DMA operations */ atmel_spi_unlock(as); - /* prepare the RX dma transfer */ - sg_init_table(&as->dma.sgrx, 1); - as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - *plen; - - /* prepare the TX dma transfer */ - sg_init_table(&as->dma.sgtx, 1); - as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - *plen; - - if (len > master->max_dma_len) - len = master->max_dma_len; - - sg_dma_len(&as->dma.sgtx) = len; - sg_dma_len(&as->dma.sgrx) = len; - - *plen = len; + *plen = xfer->len; if (atmel_spi_dma_slave_config(as, &slave_config, xfer->bits_per_word)) goto err_exit; /* Send both scatterlists */ - rxdesc = dmaengine_prep_slave_sg(rxchan, &as->dma.sgrx, 1, + rxdesc = dmaengine_prep_slave_sg(rxchan, + xfer->rx_sg.sgl, xfer->rx_sg.nents, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!rxdesc) goto err_dma; - txdesc = dmaengine_prep_slave_sg(txchan, &as->dma.sgtx, 1, + txdesc = dmaengine_prep_slave_sg(txchan, + xfer->tx_sg.sgl, xfer->tx_sg.nents, DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!txdesc) @@ -804,15 +798,10 @@ static void atmel_spi_next_xfer_data(struct spi_master *master, dma_addr_t *rx_dma, u32 *plen) { - struct atmel_spi *as = spi_master_get_devdata(master); - u32 len = *plen; - *rx_dma = xfer->rx_dma + xfer->len - *plen; *tx_dma = xfer->tx_dma + xfer->len - *plen; - if (len > master->max_dma_len) - len = master->max_dma_len; - - *plen = len; + if (*plen > master->max_dma_len) + *plen = master->max_dma_len; } static int atmel_spi_set_xfer_speed(struct atmel_spi *as, @@ -1252,7 +1241,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, * better fault reporting. */ if ((!msg->is_dma_mapped) - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) { + && as->use_pdc) { if (atmel_spi_dma_map_xfer(as, xfer) < 0) return -ENOMEM; } @@ -1329,7 +1318,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, } if (!msg->is_dma_mapped - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) + && as->use_pdc) atmel_spi_dma_unmap_xfer(master, xfer); return 0; @@ -1340,7 +1329,7 @@ static int atmel_spi_one_transfer(struct spi_master *master, } if (!msg->is_dma_mapped - && (atmel_spi_use_dma(as, xfer) || as->use_pdc)) + && as->use_pdc) atmel_spi_dma_unmap_xfer(master, xfer); if (xfer->delay_usecs) @@ -1518,6 +1507,7 @@ static int atmel_spi_probe(struct platform_device *pdev) master->cleanup = atmel_spi_cleanup; master->auto_runtime_pm = true; master->max_dma_len = SPI_MAX_DMA_XFER; + master->can_dma = atmel_spi_can_dma; platform_set_drvdata(pdev, master); as = spi_master_get_devdata(master); @@ -1554,10 +1544,13 @@ static int atmel_spi_probe(struct platform_device *pdev) as->use_pdc = false; if (as->caps.has_dma_support) { ret = atmel_spi_configure_dma(as); - if (ret == 0) + if (ret == 0) { + master->dma_tx = as->dma.chan_tx; + master->dma_rx = as->dma.chan_rx; as->use_dma = true; - else if (ret == -EPROBE_DEFER) + } else if (ret == -EPROBE_DEFER) { return ret; + } } else { as->use_pdc = true; }