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>

1 files changed, 61 insertions, 78 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index bfa5e7e5df5a..c77cfe654b0e 100644
--- 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)