spi: rspi: Merge rspi_*_dma() into rspi_dma_transfer()

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>

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index bfa5e7e..c77cfe6 100644 (file)
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -463,30 +463,67 @@ 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);
@@ -494,9 +531,14 @@ static int rspi_send_dma(struct rspi_data *rspi, struct sg_table *tx)
                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;
 }
 
@@ -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)
 {
@@ -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)