1 files changed, 56 insertions, 76 deletions

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index c47f95879833..d5157b2222ce 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -419,16 +419,13 @@ 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;
@@ -449,7 +446,10 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
 {
         struct omap2_mcspi      *mcspi;
         struct omap2_mcspi_dma  *mcspi_dma;
-        unsigned int            count, dma_count;
+        unsigned int            count, transfer_reduction = 0;
+        struct scatterlist      *sg_out[2];
+        int                     nb_sizes = 0, out_mapped_nents[2], ret, x;
+        size_t                  sizes[2];
         u32                     l;
         int                     elements = 0;
         int                     word_len, element_count;
@@ -457,7 +457,6 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
         mcspi = spi_master_get_devdata(spi->master);
         mcspi_dma = &mcspi->dma_channels[spi->chip_select];
         count = xfer->len;
-        dma_count = xfer->len;
 
         /*
          *  In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
@@ -465,7 +464,7 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
          *  normal mode.
          */
         if (mcspi->fifo_depth == 0)
-                dma_count -= es;
+                transfer_reduction = es;
 
         word_len = cs->word_len;
         l = mcspi_cached_chconf0(spi);
@@ -479,7 +478,6 @@ 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);
 
@@ -488,15 +486,38 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
                  *  configured in turbo mode.
                  */
                 if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
-                        dma_count -= es;
+                        transfer_reduction += es;
 
-                sg_init_table(&sg, 1);
-                sg_dma_address(&sg) = xfer->rx_dma;
-                sg_dma_len(&sg) = dma_count;
+                if (transfer_reduction) {
+                        /* Split sgl into two. The second sgl won't be used. */
+                        sizes[0] = count - transfer_reduction;
+                        sizes[1] = transfer_reduction;
+                        nb_sizes = 2;
+                } else {
+                        /*
+                         * Don't bother splitting the sgl. This essentially
+                         * clones the original sgl.
+                         */
+                        sizes[0] = count;
+                        nb_sizes = 1;
+                }
+
+                ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
+                               0, nb_sizes,
+                               sizes,
+                               sg_out, out_mapped_nents,
+                               GFP_KERNEL);
 
-                tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
-                                DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
-                                DMA_CTRL_ACK);
+                if (ret < 0) {
+                        dev_err(&spi->dev, "sg_split failed\n");
+                        return 0;
+                }
+
+                tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
+                                             sg_out[0],
+                                             out_mapped_nents[0],
+                                             DMA_DEV_TO_MEM,
+                                             DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
                 if (tx) {
                         tx->callback = omap2_mcspi_rx_callback;
                         tx->callback_param = spi;
@@ -510,8 +531,9 @@ 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);
+
+        for (x = 0; x < nb_sizes; x++)
+                kfree(sg_out[x]);
 
         if (mcspi->fifo_depth > 0)
                 return count;
@@ -628,8 +650,6 @@ 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;
@@ -1087,8 +1107,9 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
                 gpio_free(spi->cs_gpio);
 }
 
-static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
-                struct spi_device *spi, struct spi_transfer *t)
+static int omap2_mcspi_transfer_one(struct spi_master *master,
+                                    struct spi_device *spi,
+                                    struct spi_transfer *t)
 {
 
         /* We only enable one channel at a time -- the one whose message is
@@ -1098,7 +1119,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
          * chipselect with the FORCE bit ... CS != channel enable.
          */
 
-        struct spi_master               *master;
+        struct omap2_mcspi              *mcspi;
         struct omap2_mcspi_dma          *mcspi_dma;
         struct omap2_mcspi_cs           *cs;
         struct omap2_mcspi_device_config *cd;
@@ -1106,7 +1127,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
         int                             status = 0;
         u32                             chconf;
 
-        master = spi->master;
+        mcspi = spi_master_get_devdata(master);
         mcspi_dma = mcspi->dma_channels + spi->chip_select;
         cs = spi->controller_state;
         cd = spi->controller_data;
@@ -1166,7 +1187,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
                 unsigned        count;
 
                 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
-                    (t->len >= DMA_MIN_BYTES))
+                    master->cur_msg_mapped &&
+                    master->can_dma(master, spi, t))
                         omap2_mcspi_set_fifo(spi, t, 1);
 
                 omap2_mcspi_set_enable(spi, 1);
@@ -1177,7 +1199,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
                                         + OMAP2_MCSPI_TX0);
 
                 if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
-                    (t->len >= DMA_MIN_BYTES))
+                    master->cur_msg_mapped &&
+                    master->can_dma(master, spi, t))
                         count = omap2_mcspi_txrx_dma(spi, t);
                 else
                         count = omap2_mcspi_txrx_pio(spi, t);
@@ -1246,55 +1269,11 @@ static int omap2_mcspi_prepare_message(struct spi_master *master,
         return 0;
 }
 
-static int omap2_mcspi_transfer_one(struct spi_master *master,
-                struct spi_device *spi, struct spi_transfer *t)
+static bool omap2_mcspi_can_dma(struct spi_master *master,
+                                struct spi_device *spi,
+                                struct spi_transfer *xfer)
 {
-        struct omap2_mcspi      *mcspi;
-        struct omap2_mcspi_dma  *mcspi_dma;
-        const void      *tx_buf = t->tx_buf;
-        void            *rx_buf = t->rx_buf;
-        unsigned        len = t->len;
-
-        mcspi = spi_master_get_devdata(master);
-        mcspi_dma = mcspi->dma_channels + spi->chip_select;
-
-        if ((len && !(rx_buf || tx_buf))) {
-                dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
-                                t->speed_hz,
-                                len,
-                                tx_buf ? "tx" : "",
-                                rx_buf ? "rx" : "",
-                                t->bits_per_word);
-                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);
+        return (xfer->len >= DMA_MIN_BYTES);
 }
 
 static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
@@ -1374,6 +1353,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
         master->setup = omap2_mcspi_setup;
         master->auto_runtime_pm = true;
         master->prepare_message = omap2_mcspi_prepare_message;
+        master->can_dma = omap2_mcspi_can_dma;
         master->transfer_one = omap2_mcspi_transfer_one;
         master->set_cs = omap2_mcspi_set_cs;
         master->cleanup = omap2_mcspi_cleanup;