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spi: rspi: Merge rspi_*_dma() into rspi_dma_transfer()
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rspi_send_dma() and rspi_send_receive_dma() are very similar. Consolidate
into a single function rspi_dma_transfer(), and add missing checks for
dmaengine_submit() failures.

Both sg_table pointer parameters can be NULL, as RSPI supports TX-only
mode, and unidirectional DMA transfers will also be needed later for
Dual/Quad DMA support.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Mark Brown <broonie@linaro.org>
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Geert Uytterhoeven authored and Mark Brown committed Jun 2, 2014
1 parent e4b52dc commit c52fb6d
Showing 1 changed file with 61 additions and 78 deletions.
139 changes: 61 additions & 78 deletions drivers/spi/spi-rspi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -463,40 +463,82 @@ static void rspi_dma_complete(void *arg)
wake_up_interruptible(&rspi->wait);
}

static int rspi_send_dma(struct rspi_data *rspi, struct sg_table *tx)
static int rspi_dma_transfer(struct rspi_data *rspi, struct sg_table *tx,
struct sg_table *rx)
{
struct dma_async_tx_descriptor *desc;
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
u8 irq_mask = 0;
unsigned int other_irq = 0;
dma_cookie_t cookie;
int ret;

desc = dmaengine_prep_slave_sg(rspi->master->dma_tx, tx->sgl,
tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc)
return -EIO;
if (tx) {
desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx,
tx->sgl, tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
return -EIO;

irq_mask |= SPCR_SPTIE;
}
if (rx) {
desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx,
rx->sgl, rx->nents, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
return -EIO;

irq_mask |= SPCR_SPRIE;
}

/*
* DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
* DMAC needs SPxIE, but if SPxIE is set, the IRQ routine will be
* called. So, this driver disables the IRQ while DMA transfer.
*/
disable_irq(rspi->tx_irq);
if (tx)
disable_irq(other_irq = rspi->tx_irq);
if (rx && rspi->rx_irq != other_irq)
disable_irq(rspi->rx_irq);

rspi_enable_irq(rspi, SPCR_SPTIE);
rspi_enable_irq(rspi, irq_mask);
rspi->dma_callbacked = 0;

desc->callback = rspi_dma_complete;
desc->callback_param = rspi;
dmaengine_submit(desc);
dma_async_issue_pending(rspi->master->dma_tx);
if (rx) {
desc_rx->callback = rspi_dma_complete;
desc_rx->callback_param = rspi;
cookie = dmaengine_submit(desc_rx);
if (dma_submit_error(cookie))
return cookie;
dma_async_issue_pending(rspi->master->dma_rx);
}
if (tx) {
if (rx) {
/* No callback */
desc_tx->callback = NULL;
} else {
desc_tx->callback = rspi_dma_complete;
desc_tx->callback_param = rspi;
}
cookie = dmaengine_submit(desc_tx);
if (dma_submit_error(cookie))
return cookie;
dma_async_issue_pending(rspi->master->dma_tx);
}

ret = wait_event_interruptible_timeout(rspi->wait,
rspi->dma_callbacked, HZ);
if (ret > 0 && rspi->dma_callbacked)
ret = 0;
else if (!ret)
ret = -ETIMEDOUT;
rspi_disable_irq(rspi, SPCR_SPTIE);

enable_irq(rspi->tx_irq);
rspi_disable_irq(rspi, irq_mask);

if (tx)
enable_irq(rspi->tx_irq);
if (rx && rspi->rx_irq != other_irq)
enable_irq(rspi->rx_irq);

return ret;
}

Expand Down Expand Up @@ -530,61 +572,6 @@ static void qspi_receive_init(const struct rspi_data *rspi)
rspi_write8(rspi, 0, QSPI_SPBFCR);
}

static int rspi_send_receive_dma(struct rspi_data *rspi, struct sg_table *tx,
struct sg_table *rx)
{
struct dma_async_tx_descriptor *desc_tx, *desc_rx;
int ret;

/* prepare transmit transfer */
desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx, tx->sgl,
tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
return -EIO;

/* prepare receive transfer */
desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx, rx->sgl,
rx->nents, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
return -EIO;

/*
* DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
* called. So, this driver disables the IRQ while DMA transfer.
*/
disable_irq(rspi->tx_irq);
if (rspi->rx_irq != rspi->tx_irq)
disable_irq(rspi->rx_irq);

rspi_enable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);
rspi->dma_callbacked = 0;

desc_rx->callback = rspi_dma_complete;
desc_rx->callback_param = rspi;
dmaengine_submit(desc_rx);
dma_async_issue_pending(rspi->master->dma_rx);

desc_tx->callback = NULL; /* No callback */
dmaengine_submit(desc_tx);
dma_async_issue_pending(rspi->master->dma_tx);

ret = wait_event_interruptible_timeout(rspi->wait,
rspi->dma_callbacked, HZ);
if (ret > 0 && rspi->dma_callbacked)
ret = 0;
else if (!ret)
ret = -ETIMEDOUT;
rspi_disable_irq(rspi, SPCR_SPTIE | SPCR_SPRIE);

enable_irq(rspi->tx_irq);
if (rspi->rx_irq != rspi->tx_irq)
enable_irq(rspi->rx_irq);

return ret;
}

static bool __rspi_can_dma(const struct rspi_data *rspi,
const struct spi_transfer *xfer)
{
Expand Down Expand Up @@ -615,13 +602,9 @@ static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
}
rspi_write8(rspi, spcr, RSPI_SPCR);

if (master->can_dma && __rspi_can_dma(rspi, xfer)) {
if (xfer->rx_buf)
return rspi_send_receive_dma(rspi, &xfer->tx_sg,
&xfer->rx_sg);
else
return rspi_send_dma(rspi, &xfer->tx_sg);
}
if (master->can_dma && __rspi_can_dma(rspi, xfer))
return rspi_dma_transfer(rspi, &xfer->tx_sg,
xfer->rx_buf ? &xfer->rx_sg : NULL);

ret = rspi_pio_transfer(rspi, xfer->tx_buf, xfer->rx_buf, xfer->len);
if (ret < 0)
Expand Down

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