Currently omap2-mcspi cannot handle dma transfer for vmalloced buffer.
I hit this problem when using mtdblock on spi-nor.
This lets the SPI core handle the page mapping for dma transfer buffer.
Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
---
drivers/spi/spi-omap2-mcspi.c | 62 ++++++++++++-------------------------------
1 file changed, 17 insertions(+), 45 deletions(-)
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 0caa3c8..43a02e3 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -423,16 +423,12 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
if (mcspi_dma->dma_tx) {
struct dma_async_tx_descriptor *tx;
- struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);
- sg_init_table(&sg, 1);
- sg_dma_address(&sg) = xfer->tx_dma;
- sg_dma_len(&sg) = xfer->len;
-
- tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
- DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
+ xfer->tx_sg.nents, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
@@ -478,20 +474,15 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
if (mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
- struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
dma_count -= es;
- sg_init_table(&sg, 1);
- sg_dma_address(&sg) = xfer->rx_dma;
- sg_dma_len(&sg) = dma_count;
-
- tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
- DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
- DMA_CTRL_ACK);
+ tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, xfer->rx_sg.sgl,
+ xfer->rx_sg.nents, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
@@ -505,8 +496,6 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
omap2_mcspi_set_dma_req(spi, 1, 1);
wait_for_completion(&mcspi_dma->dma_rx_completion);
- dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
- DMA_FROM_DEVICE);
if (mcspi->fifo_depth > 0)
return count;
@@ -619,8 +608,6 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
- dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
- DMA_TO_DEVICE);
if (mcspi->fifo_depth > 0) {
irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
@@ -1087,6 +1074,16 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
gpio_free(spi->cs_gpio);
}
+static bool omap2_mcspi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ if (xfer->len < DMA_MIN_BYTES)
+ return false;
+
+ return true;
+}
+
static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
struct spi_device *spi, struct spi_transfer *t)
{
@@ -1268,32 +1265,6 @@ static int omap2_mcspi_transfer_one(struct spi_master *master,
return -EINVAL;
}
- if (len < DMA_MIN_BYTES)
- goto skip_dma_map;
-
- if (mcspi_dma->dma_tx && tx_buf != NULL) {
- t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
- len, DMA_TO_DEVICE);
- if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
- dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
- 'T', len);
- return -EINVAL;
- }
- }
- if (mcspi_dma->dma_rx && rx_buf != NULL) {
- t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
- dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
- 'R', len);
- if (tx_buf != NULL)
- dma_unmap_single(mcspi->dev, t->tx_dma,
- len, DMA_TO_DEVICE);
- return -EINVAL;
- }
- }
-
-skip_dma_map:
return omap2_mcspi_work_one(mcspi, spi, t);
}
@@ -1377,6 +1348,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
master->transfer_one = omap2_mcspi_transfer_one;
master->set_cs = omap2_mcspi_set_cs;
master->cleanup = omap2_mcspi_cleanup;
+ master->can_dma = omap2_mcspi_can_dma;
master->dev.of_node = node;
master->max_speed_hz = OMAP2_MCSPI_MAX_FREQ;
master->min_speed_hz = OMAP2_MCSPI_MAX_FREQ >> 15;
--
2.5.0
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