spi: dw-mid: move to use core SPI DMA mappings

SPI core has a comprehensive function set to map and unmap a message when it's
needed. This patch converts driver to use that advantage.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

3 files changed, 43 insertions, 66 deletions

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index e614190daef6..599dad40a3ec 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -69,6 +69,7 @@ static int mid_spi_dma_init(struct dw_spi *dws)
         rxs->hs_mode = LNW_DMA_HW_HS;
         rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
         dws->rxchan->private = rxs;
+        dws->master->dma_rx = dws->rxchan;
 
         /* 2. Init tx channel */
         dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
@@ -78,6 +79,7 @@ static int mid_spi_dma_init(struct dw_spi *dws)
         txs->hs_mode = LNW_DMA_HW_HS;
         txs->cfg_mode = LNW_DMA_MEM_TO_PER;
         dws->txchan->private = txs;
+        dws->master->dma_tx = dws->txchan;
 
         dws->dma_inited = 1;
         return 0;
@@ -116,6 +118,17 @@ static irqreturn_t dma_transfer(struct dw_spi *dws)
         return IRQ_HANDLED;
 }
 
+static bool mid_spi_can_dma(struct spi_master *master, struct spi_device *spi,
+                struct spi_transfer *xfer)
+{
+        struct dw_spi *dws = spi_master_get_devdata(master);
+
+        if (!dws->dma_inited)
+                return false;
+
+        return xfer->len > dws->fifo_len;
+}
+
 static enum dma_slave_buswidth convert_dma_width(u32 dma_width) {
         if (dma_width == 1)
                 return DMA_SLAVE_BUSWIDTH_1_BYTE;
@@ -139,12 +152,13 @@ static void dw_spi_dma_tx_done(void *arg)
         spi_finalize_current_transfer(dws->master);
 }
 
-static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
+static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
+                struct spi_transfer *xfer)
 {
         struct dma_slave_config txconf;
         struct dma_async_tx_descriptor *txdesc;
 
-        if (!dws->tx_dma)
+        if (!xfer->tx_buf)
                 return NULL;
 
         txconf.direction = DMA_MEM_TO_DEV;
@@ -156,13 +170,9 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
 
         dmaengine_slave_config(dws->txchan, &txconf);
 
-        memset(&dws->tx_sgl, 0, sizeof(dws->tx_sgl));
-        dws->tx_sgl.dma_address = dws->tx_dma;
-        dws->tx_sgl.length = dws->len;
-
         txdesc = dmaengine_prep_slave_sg(dws->txchan,
-                                &dws->tx_sgl,
-                                1,
+                                xfer->tx_sg.sgl,
+                                xfer->tx_sg.nents,
                                 DMA_MEM_TO_DEV,
                                 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
         if (!txdesc)
@@ -188,12 +198,13 @@ static void dw_spi_dma_rx_done(void *arg)
         spi_finalize_current_transfer(dws->master);
 }
 
-static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
+static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
+                struct spi_transfer *xfer)
 {
         struct dma_slave_config rxconf;
         struct dma_async_tx_descriptor *rxdesc;
 
-        if (!dws->rx_dma)
+        if (!xfer->rx_buf)
                 return NULL;
 
         rxconf.direction = DMA_DEV_TO_MEM;
@@ -205,13 +216,9 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
 
         dmaengine_slave_config(dws->rxchan, &rxconf);
 
-        memset(&dws->rx_sgl, 0, sizeof(dws->rx_sgl));
-        dws->rx_sgl.dma_address = dws->rx_dma;
-        dws->rx_sgl.length = dws->len;
-
         rxdesc = dmaengine_prep_slave_sg(dws->rxchan,
-                                &dws->rx_sgl,
-                                1,
+                                xfer->rx_sg.sgl,
+                                xfer->rx_sg.nents,
                                 DMA_DEV_TO_MEM,
                                 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
         if (!rxdesc)
@@ -223,16 +230,16 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
         return rxdesc;
 }
 
-static int mid_spi_dma_setup(struct dw_spi *dws)
+static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 {
         u16 dma_ctrl = 0;
 
         dw_writew(dws, DW_SPI_DMARDLR, 0xf);
         dw_writew(dws, DW_SPI_DMATDLR, 0x10);
 
-        if (dws->tx_dma)
+        if (xfer->tx_buf)
                 dma_ctrl |= SPI_DMA_TDMAE;
-        if (dws->rx_dma)
+        if (xfer->rx_buf)
                 dma_ctrl |= SPI_DMA_RDMAE;
         dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
 
@@ -244,15 +251,15 @@ static int mid_spi_dma_setup(struct dw_spi *dws)
         return 0;
 }
 
-static int mid_spi_dma_transfer(struct dw_spi *dws)
+static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
 {
         struct dma_async_tx_descriptor *txdesc, *rxdesc;
 
         /* Prepare the TX dma transfer */
-        txdesc = dw_spi_dma_prepare_tx(dws);
+        txdesc = dw_spi_dma_prepare_tx(dws, xfer);
 
         /* Prepare the RX dma transfer */
-        rxdesc = dw_spi_dma_prepare_rx(dws);
+        rxdesc = dw_spi_dma_prepare_rx(dws, xfer);
 
         /* rx must be started before tx due to spi instinct */
         if (rxdesc) {
@@ -286,6 +293,7 @@ static struct dw_spi_dma_ops mid_dma_ops = {
         .dma_init       = mid_spi_dma_init,
         .dma_exit       = mid_spi_dma_exit,
         .dma_setup      = mid_spi_dma_setup,
+        .can_dma        = mid_spi_can_dma,
         .dma_transfer   = mid_spi_dma_transfer,
         .dma_stop       = mid_spi_dma_stop,
 };
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index d53cffe7ff22..2437bfcbf2f8 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -217,32 +217,6 @@ static void dw_reader(struct dw_spi *dws)
         }
 }
 
-/*
- * Note: first step is the protocol driver prepares
- * a dma-capable memory, and this func just need translate
- * the virt addr to physical
- */
-static int map_dma_buffers(struct spi_master *master,
-                struct spi_device *spi, struct spi_transfer *transfer)
-{
-        struct dw_spi *dws = spi_master_get_devdata(master);
-        struct chip_data *chip = spi_get_ctldata(spi);
-
-        if (!master->cur_msg->is_dma_mapped
-                || !dws->dma_inited
-                || !chip->enable_dma
-                || !dws->dma_ops)
-                return 0;
-
-        if (transfer->tx_dma)
-                dws->tx_dma = transfer->tx_dma;
-
-        if (transfer->rx_dma)
-                dws->rx_dma = transfer->rx_dma;
-
-        return 1;
-}
-
 static void int_error_stop(struct dw_spi *dws, const char *msg)
 {
         spi_reset_chip(dws);
@@ -322,11 +296,10 @@ static int dw_spi_transfer_one(struct spi_master *master,
         u32 cr0 = 0;
         int ret;
 
+        dws->dma_mapped = 0;
         dws->n_bytes = chip->n_bytes;
         dws->dma_width = chip->dma_width;
 
-        dws->rx_dma = transfer->rx_dma;
-        dws->tx_dma = transfer->tx_dma;
         dws->tx = (void *)transfer->tx_buf;
         dws->tx_end = dws->tx + transfer->len;
         dws->rx = transfer->rx_buf;
@@ -386,7 +359,8 @@ static int dw_spi_transfer_one(struct spi_master *master,
         dw_writew(dws, DW_SPI_CTRL0, cr0);
 
         /* Check if current transfer is a DMA transaction */
-        dws->dma_mapped = map_dma_buffers(master, spi, transfer);
+        if (master->can_dma && master->can_dma(master, spi, transfer))
+                dws->dma_mapped = master->cur_msg_mapped;
 
         /* For poll mode just disable all interrupts */
         spi_mask_intr(dws, 0xff);
@@ -396,7 +370,7 @@ static int dw_spi_transfer_one(struct spi_master *master,
          * we only need set the TXEI IRQ, as TX/RX always happen syncronizely
          */
         if (dws->dma_mapped) {
-                ret = dws->dma_ops->dma_setup(dws);
+                ret = dws->dma_ops->dma_setup(dws, transfer);
                 if (ret < 0) {
                         spi_enable_chip(dws, 1);
                         return ret;
@@ -416,7 +390,7 @@ static int dw_spi_transfer_one(struct spi_master *master,
         spi_enable_chip(dws, 1);
 
         if (dws->dma_mapped) {
-                ret = dws->dma_ops->dma_transfer(dws);
+                ret = dws->dma_ops->dma_transfer(dws, transfer);
                 if (ret < 0)
                         return ret;
         }
@@ -470,8 +444,6 @@ static int dw_spi_setup(struct spi_device *spi)
 
                 chip->rx_threshold = 0;
                 chip->tx_threshold = 0;
-
-                chip->enable_dma = chip_info->enable_dma;
         }
 
         if (spi->bits_per_word == 8) {
@@ -584,6 +556,8 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
                 if (ret) {
                         dev_warn(dev, "DMA init failed\n");
                         dws->dma_inited = 0;
+                } else {
+                        master->can_dma = dws->dma_ops->can_dma;
                 }
         }
 
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 7f130bd8f37a..f298df59381b 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -91,8 +91,10 @@ struct dw_spi;
 struct dw_spi_dma_ops {
         int (*dma_init)(struct dw_spi *dws);
         void (*dma_exit)(struct dw_spi *dws);
-        int (*dma_setup)(struct dw_spi *dws);
-        int (*dma_transfer)(struct dw_spi *dws);
+        int (*dma_setup)(struct dw_spi *dws, struct spi_transfer *xfer);
+        bool (*can_dma)(struct spi_master *master, struct spi_device *spi,
+                        struct spi_transfer *xfer);
+        int (*dma_transfer)(struct dw_spi *dws, struct spi_transfer *xfer);
         void (*dma_stop)(struct dw_spi *dws);
 };
 
@@ -117,20 +119,14 @@ struct dw_spi {
         void                    *rx;
         void                    *rx_end;
         int                     dma_mapped;
-        dma_addr_t              rx_dma;
-        dma_addr_t              tx_dma;
-        size_t                  rx_map_len;
-        size_t                  tx_map_len;
         u8                      n_bytes;        /* current is a 1/2 bytes op */
         u32                     dma_width;
         irqreturn_t             (*transfer_handler)(struct dw_spi *dws);
 
-        /* Dma info */
+        /* DMA info */
         int                     dma_inited;
         struct dma_chan         *txchan;
-        struct scatterlist      tx_sgl;
         struct dma_chan         *rxchan;
-        struct scatterlist      rx_sgl;
         unsigned long           dma_chan_busy;
         struct device           *dma_dev;
         dma_addr_t              dma_addr; /* phy address of the Data register */
@@ -206,14 +202,13 @@ static inline void spi_reset_chip(struct dw_spi *dws)
 
 /*
  * Each SPI slave device to work with dw_api controller should
- * has such a structure claiming its working mode (PIO/DMA etc),
+ * has such a structure claiming its working mode (poll or PIO/DMA),
  * which can be save in the "controller_data" member of the
  * struct spi_device.
  */
 struct dw_spi_chip {
         u8 poll_mode;   /* 1 for controller polling mode */
         u8 type;        /* SPI/SSP/MicroWire */
-        u8 enable_dma;
         void (*cs_control)(u32 command);
 };