1 files changed, 50 insertions, 90 deletions

diff --git a/drivers/spi/spi-rspi.c b/drivers/spi/spi-rspi.c
index 7b993f75a3cf..753ac7bdfd55 100644
--- a/drivers/spi/spi-rspi.c
+++ b/drivers/spi/spi-rspi.c
@@ -195,10 +195,6 @@ struct rspi_data {
         int rx_irq, tx_irq;
         const struct spi_ops *ops;
 
-        /* for dmaengine */
-        struct dma_chan *chan_tx;
-        struct dma_chan *chan_rx;
-
         unsigned dma_callbacked:1;
         unsigned byte_access:1;
 };
@@ -251,6 +247,7 @@ struct spi_ops {
                             struct spi_transfer *xfer);
         u16 mode_bits;
         u16 flags;
+        u16 fifo_size;
 };
 
 /*
@@ -466,39 +463,16 @@ static void rspi_dma_complete(void *arg)
         wake_up_interruptible(&rspi->wait);
 }
 
-static int rspi_dma_map_sg(struct scatterlist *sg, const void *buf,
-                           unsigned len, struct dma_chan *chan,
-                           enum dma_transfer_direction dir)
-{
-        sg_init_table(sg, 1);
-        sg_set_buf(sg, buf, len);
-        sg_dma_len(sg) = len;
-        return dma_map_sg(chan->device->dev, sg, 1, dir);
-}
-
-static void rspi_dma_unmap_sg(struct scatterlist *sg, struct dma_chan *chan,
-                              enum dma_transfer_direction dir)
-{
-        dma_unmap_sg(chan->device->dev, sg, 1, dir);
-}
-
 static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
 {
-        struct scatterlist sg;
-        const void *buf = t->tx_buf;
         struct dma_async_tx_descriptor *desc;
-        unsigned int len = t->len;
-        int ret = 0;
-
-        if (!rspi_dma_map_sg(&sg, buf, len, rspi->chan_tx, DMA_TO_DEVICE))
-                return -EFAULT;
+        int ret;
 
-        desc = dmaengine_prep_slave_sg(rspi->chan_tx, &sg, 1, DMA_TO_DEVICE,
+        desc = dmaengine_prep_slave_sg(rspi->master->dma_tx, t->tx_sg.sgl,
+                                       t->tx_sg.nents, DMA_TO_DEVICE,
                                        DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-        if (!desc) {
-                ret = -EIO;
-                goto end;
-        }
+        if (!desc)
+                return -EIO;
 
         /*
          * DMAC needs SPTIE, but if SPTIE is set, this IRQ routine will be
@@ -513,7 +487,7 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
         desc->callback = rspi_dma_complete;
         desc->callback_param = rspi;
         dmaengine_submit(desc);
-        dma_async_issue_pending(rspi->chan_tx);
+        dma_async_issue_pending(rspi->master->dma_tx);
 
         ret = wait_event_interruptible_timeout(rspi->wait,
                                                rspi->dma_callbacked, HZ);
@@ -524,9 +498,6 @@ static int rspi_send_dma(struct rspi_data *rspi, struct spi_transfer *t)
         rspi_disable_irq(rspi, SPCR_SPTIE);
 
         enable_irq(rspi->tx_irq);
-
-end:
-        rspi_dma_unmap_sg(&sg, rspi->chan_tx, DMA_TO_DEVICE);
         return ret;
 }
 
@@ -562,39 +533,22 @@ static void qspi_receive_init(const struct rspi_data *rspi)
 
 static int rspi_send_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
 {
-        struct scatterlist sg_rx, sg_tx;
-        const void *tx_buf = t->tx_buf;
-        void *rx_buf = t->rx_buf;
         struct dma_async_tx_descriptor *desc_tx, *desc_rx;
-        unsigned int len = t->len;
-        int ret = 0;
+        int ret;
 
         /* prepare transmit transfer */
-        if (!rspi_dma_map_sg(&sg_tx, tx_buf, len, rspi->chan_tx,
-                             DMA_TO_DEVICE))
-                return -EFAULT;
-
-        desc_tx = dmaengine_prep_slave_sg(rspi->chan_tx, &sg_tx, 1,
-                        DMA_TO_DEVICE, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-        if (!desc_tx) {
-                ret = -EIO;
-                goto end_tx_mapped;
-        }
+        desc_tx = dmaengine_prep_slave_sg(rspi->master->dma_tx, t->tx_sg.sgl,
+                                          t->tx_sg.nents, DMA_TO_DEVICE,
+                                          DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+        if (!desc_tx)
+                return -EIO;
 
         /* prepare receive transfer */
-        if (!rspi_dma_map_sg(&sg_rx, rx_buf, len, rspi->chan_rx,
-                             DMA_FROM_DEVICE)) {
-                ret = -EFAULT;
-                goto end_tx_mapped;
-
-        }
-        desc_rx = dmaengine_prep_slave_sg(rspi->chan_rx, &sg_rx, 1,
-                                          DMA_FROM_DEVICE,
+        desc_rx = dmaengine_prep_slave_sg(rspi->master->dma_rx, t->rx_sg.sgl,
+                                          t->rx_sg.nents, DMA_FROM_DEVICE,
                                           DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
-        if (!desc_rx) {
-                ret = -EIO;
-                goto end;
-        }
+        if (!desc_rx)
+                return -EIO;
 
         rspi_receive_init(rspi);
 
@@ -613,11 +567,11 @@ static int rspi_send_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
         desc_rx->callback = rspi_dma_complete;
         desc_rx->callback_param = rspi;
         dmaengine_submit(desc_rx);
-        dma_async_issue_pending(rspi->chan_rx);
+        dma_async_issue_pending(rspi->master->dma_rx);
 
         desc_tx->callback = NULL;       /* No callback */
         dmaengine_submit(desc_tx);
-        dma_async_issue_pending(rspi->chan_tx);
+        dma_async_issue_pending(rspi->master->dma_tx);
 
         ret = wait_event_interruptible_timeout(rspi->wait,
                                                rspi->dma_callbacked, HZ);
@@ -631,19 +585,21 @@ static int rspi_send_receive_dma(struct rspi_data *rspi, struct spi_transfer *t)
         if (rspi->rx_irq != rspi->tx_irq)
                 enable_irq(rspi->rx_irq);
 
-end:
-        rspi_dma_unmap_sg(&sg_rx, rspi->chan_rx, DMA_FROM_DEVICE);
-end_tx_mapped:
-        rspi_dma_unmap_sg(&sg_tx, rspi->chan_tx, DMA_TO_DEVICE);
         return ret;
 }
 
-static int rspi_is_dma(const struct rspi_data *rspi, struct spi_transfer *t)
+static bool __rspi_can_dma(const struct rspi_data *rspi,
+                           const struct spi_transfer *xfer)
 {
-        if (rspi->chan_tx)
-                return 1;
+        return xfer->len > rspi->ops->fifo_size;
+}
 
-        return 0;
+static bool rspi_can_dma(struct spi_master *master, struct spi_device *spi,
+                         struct spi_transfer *xfer)
+{
+        struct rspi_data *rspi = spi_master_get_devdata(master);
+
+        return __rspi_can_dma(rspi, xfer);
 }
 
 static int rspi_transfer_out_in(struct rspi_data *rspi,
@@ -676,7 +632,7 @@ static int rspi_transfer_one(struct spi_master *master, struct spi_device *spi,
 {
         struct rspi_data *rspi = spi_master_get_devdata(master);
 
-        if (!rspi_is_dma(rspi, xfer))
+        if (!master->can_dma || !__rspi_can_dma(rspi, xfer))
                 return rspi_transfer_out_in(rspi, xfer);
 
         if (xfer->rx_buf)
@@ -976,7 +932,7 @@ static struct dma_chan *rspi_request_dma_chan(struct device *dev,
         return chan;
 }
 
-static int rspi_request_dma(struct device *dev, struct rspi_data *rspi,
+static int rspi_request_dma(struct device *dev, struct spi_master *master,
                             const struct resource *res)
 {
         const struct rspi_plat_data *rspi_pd = dev_get_platdata(dev);
@@ -984,31 +940,32 @@ static int rspi_request_dma(struct device *dev, struct rspi_data *rspi,
         if (!rspi_pd || !rspi_pd->dma_rx_id || !rspi_pd->dma_tx_id)
                 return 0;       /* The driver assumes no error. */
 
-        rspi->chan_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM,
-                                              rspi_pd->dma_rx_id,
-                                              res->start + RSPI_SPDR);
-        if (!rspi->chan_rx)
+        master->dma_rx = rspi_request_dma_chan(dev, DMA_DEV_TO_MEM,
+                                               rspi_pd->dma_rx_id,
+                                               res->start + RSPI_SPDR);
+        if (!master->dma_rx)
                 return -ENODEV;
 
-        rspi->chan_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV,
-                                              rspi_pd->dma_tx_id,
-                                              res->start + RSPI_SPDR);
-        if (!rspi->chan_tx) {
-                dma_release_channel(rspi->chan_rx);
-                rspi->chan_rx = NULL;
+        master->dma_tx = rspi_request_dma_chan(dev, DMA_MEM_TO_DEV,
+                                               rspi_pd->dma_tx_id,
+                                               res->start + RSPI_SPDR);
+        if (!master->dma_tx) {
+                dma_release_channel(master->dma_rx);
+                master->dma_rx = NULL;
                 return -ENODEV;
         }
 
+        master->can_dma = rspi_can_dma;
         dev_info(dev, "DMA available");
         return 0;
 }
 
 static void rspi_release_dma(struct rspi_data *rspi)
 {
-        if (rspi->chan_tx)
-                dma_release_channel(rspi->chan_tx);
-        if (rspi->chan_rx)
-                dma_release_channel(rspi->chan_rx);
+        if (rspi->master->dma_tx)
+                dma_release_channel(rspi->master->dma_tx);
+        if (rspi->master->dma_rx)
+                dma_release_channel(rspi->master->dma_rx);
 }
 
 static int rspi_remove(struct platform_device *pdev)
@@ -1026,6 +983,7 @@ static const struct spi_ops rspi_ops = {
         .transfer_one =         rspi_transfer_one,
         .mode_bits =            SPI_CPHA | SPI_CPOL | SPI_LOOP,
         .flags =                SPI_MASTER_MUST_TX,
+        .fifo_size =            8,
 };
 
 static const struct spi_ops rspi_rz_ops = {
@@ -1033,6 +991,7 @@ static const struct spi_ops rspi_rz_ops = {
         .transfer_one =         rspi_rz_transfer_one,
         .mode_bits =            SPI_CPHA | SPI_CPOL | SPI_LOOP,
         .flags =                SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
+        .fifo_size =            8,      /* 8 for TX, 32 for RX */
 };
 
 static const struct spi_ops qspi_ops = {
@@ -1042,6 +1001,7 @@ static const struct spi_ops qspi_ops = {
                                 SPI_TX_DUAL | SPI_TX_QUAD |
                                 SPI_RX_DUAL | SPI_RX_QUAD,
         .flags =                SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX,
+        .fifo_size =            32,
 };
 
 #ifdef CONFIG_OF
@@ -1199,7 +1159,7 @@ static int rspi_probe(struct platform_device *pdev)
                 goto error2;
         }
 
-        ret = rspi_request_dma(&pdev->dev, rspi, res);
+        ret = rspi_request_dma(&pdev->dev, master, res);
         if (ret < 0)
                 dev_warn(&pdev->dev, "DMA not available, using PIO\n");