diff options
Diffstat (limited to 'drivers/spi/davinci_spi.c')
| -rw-r--r-- | drivers/spi/davinci_spi.c | 43 |
1 files changed, 30 insertions, 13 deletions
diff --git a/drivers/spi/davinci_spi.c b/drivers/spi/davinci_spi.c index 166a879..1f0ed80 100644 --- a/drivers/spi/davinci_spi.c +++ b/drivers/spi/davinci_spi.c @@ -571,6 +571,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) unsigned long tx_reg, rx_reg; struct edmacc_param param; void *rx_buf; + int b, c; dma = &dspi->dma; @@ -591,22 +592,38 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) if (t->tx_buf) { t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf, - dspi->wcount, DMA_TO_DEVICE); + t->len, DMA_TO_DEVICE); if (dma_mapping_error(&spi->dev, t->tx_dma)) { dev_dbg(sdev, "Unable to DMA map %d bytes" - "TX buffer\n", dspi->wcount); + "TX buffer\n", t->len); return -ENOMEM; } } + /* + * If number of words is greater than 65535, then we need + * to configure a 3 dimension transfer. Use the BCNTRLD + * feature to allow for transfers that aren't even multiples + * of 65535 (or any other possible b size) by first transferring + * the remainder amount then grabbing the next N blocks of + * 65535 words. + */ + + c = dspi->wcount / (SZ_64K - 1); /* N 65535 Blocks */ + b = dspi->wcount - c * (SZ_64K - 1); /* Remainder */ + if (b) + c++; + else + b = SZ_64K - 1; + param.opt = TCINTEN | EDMA_TCC(dma->tx_channel); param.src = t->tx_buf ? t->tx_dma : tx_reg; - param.a_b_cnt = dspi->wcount << 16 | data_type; + param.a_b_cnt = b << 16 | data_type; param.dst = tx_reg; param.src_dst_bidx = t->tx_buf ? data_type : 0; - param.link_bcntrld = 0xffff; - param.src_dst_cidx = 0; - param.ccnt = 1; + param.link_bcntrld = 0xffffffff; + param.src_dst_cidx = t->tx_buf ? data_type : 0; + param.ccnt = c; edma_write_slot(dma->tx_channel, ¶m); edma_link(dma->tx_channel, dma->dummy_param_slot); @@ -624,7 +641,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) if (t->rx_buf) { rx_buf = t->rx_buf; - rx_buf_count = dspi->rcount; + rx_buf_count = t->len; } else { rx_buf = dspi->rx_tmp_buf; rx_buf_count = sizeof(dspi->rx_tmp_buf); @@ -636,19 +653,19 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n", rx_buf_count); if (t->tx_buf) - dma_unmap_single(NULL, t->tx_dma, dspi->wcount, + dma_unmap_single(NULL, t->tx_dma, t->len, DMA_TO_DEVICE); return -ENOMEM; } param.opt = TCINTEN | EDMA_TCC(dma->rx_channel); param.src = rx_reg; - param.a_b_cnt = dspi->rcount << 16 | data_type; + param.a_b_cnt = b << 16 | data_type; param.dst = t->rx_dma; param.src_dst_bidx = (t->rx_buf ? data_type : 0) << 16; - param.link_bcntrld = 0xffff; - param.src_dst_cidx = 0; - param.ccnt = 1; + param.link_bcntrld = 0xffffffff; + param.src_dst_cidx = (t->rx_buf ? data_type : 0) << 16; + param.ccnt = c; edma_write_slot(dma->rx_channel, ¶m); if (pdata->cshold_bug) @@ -675,7 +692,7 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t) if (spicfg->io_type == SPI_IO_TYPE_DMA) { if (t->tx_buf) - dma_unmap_single(NULL, t->tx_dma, dspi->wcount, + dma_unmap_single(NULL, t->tx_dma, t->len, DMA_TO_DEVICE); dma_unmap_single(NULL, t->rx_dma, rx_buf_count, |