spi: dw-mid: refactor to use helpers

This patch splits few helpers, namely dw_spi_dma_prepare_rx(),
dw_spi_dma_prepare_tx(), and dw_spi_dma_setup() which will be useful for the
consequent improvements.

There is no functional change.

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

1 files changed, 48 insertions, 21 deletions

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index 46c6d58e1fda..c8319ab0bbdf 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -111,28 +111,11 @@ static void dw_spi_dma_done(void *arg)
         dw_spi_xfer_done(dws);
 }
 
-static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
+static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
 {
-        struct dma_async_tx_descriptor *txdesc, *rxdesc;
-        struct dma_slave_config txconf, rxconf;
-        u16 dma_ctrl = 0;
-
-        /* 1. setup DMA related registers */
-        if (cs_change) {
-                spi_enable_chip(dws, 0);
-                dw_writew(dws, DW_SPI_DMARDLR, 0xf);
-                dw_writew(dws, DW_SPI_DMATDLR, 0x10);
-                if (dws->tx_dma)
-                        dma_ctrl |= SPI_DMA_TDMAE;
-                if (dws->rx_dma)
-                        dma_ctrl |= SPI_DMA_RDMAE;
-                dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
-                spi_enable_chip(dws, 1);
-        }
+        struct dma_slave_config txconf;
+        struct dma_async_tx_descriptor *txdesc;
 
-        dws->dma_chan_done = 0;
-
-        /* 2. Prepare the TX dma transfer */
         txconf.direction = DMA_MEM_TO_DEV;
         txconf.dst_addr = dws->dma_addr;
         txconf.dst_maxburst = LNW_DMA_MSIZE_16;
@@ -154,7 +137,14 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
         txdesc->callback = dw_spi_dma_done;
         txdesc->callback_param = dws;
 
-        /* 3. Prepare the RX dma transfer */
+        return txdesc;
+}
+
+static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
+{
+        struct dma_slave_config rxconf;
+        struct dma_async_tx_descriptor *rxdesc;
+
         rxconf.direction = DMA_DEV_TO_MEM;
         rxconf.src_addr = dws->dma_addr;
         rxconf.src_maxburst = LNW_DMA_MSIZE_16;
@@ -176,6 +166,43 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
         rxdesc->callback = dw_spi_dma_done;
         rxdesc->callback_param = dws;
 
+        return rxdesc;
+}
+
+static void dw_spi_dma_setup(struct dw_spi *dws)
+{
+        u16 dma_ctrl = 0;
+
+        spi_enable_chip(dws, 0);
+
+        dw_writew(dws, DW_SPI_DMARDLR, 0xf);
+        dw_writew(dws, DW_SPI_DMATDLR, 0x10);
+
+        if (dws->tx_dma)
+                dma_ctrl |= SPI_DMA_TDMAE;
+        if (dws->rx_dma)
+                dma_ctrl |= SPI_DMA_RDMAE;
+        dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
+
+        spi_enable_chip(dws, 1);
+}
+
+static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
+{
+        struct dma_async_tx_descriptor *txdesc, *rxdesc;
+
+        /* 1. setup DMA related registers */
+        if (cs_change)
+                dw_spi_dma_setup(dws);
+
+        dws->dma_chan_done = 0;
+
+        /* 2. Prepare the TX dma transfer */
+        txdesc = dw_spi_dma_prepare_tx(dws);
+
+        /* 3. Prepare the RX dma transfer */
+        rxdesc = dw_spi_dma_prepare_rx(dws);
+
         /* rx must be started before tx due to spi instinct */
         dmaengine_submit(rxdesc);
         dma_async_issue_pending(dws->rxchan);