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authorAndy Shevchenko <andriy.shevchenko@linux.intel.com>2014-10-28 18:25:01 +0200
committerMark Brown <broonie@kernel.org>2014-10-28 22:40:38 +0000
commita5c2db964d3eb26b41bd7abc1b13486f732b3aa2 (patch)
treec1ac9e5491f7c46ca33f56fba0fed223d35aee7b /drivers/spi/spi-dw-mid.c
parentb7a40242c82cd73cfcea305f23e67d068dd8401a (diff)
downloadlinux-a5c2db964d3eb26b41bd7abc1b13486f732b3aa2.tar.bz2
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>
Diffstat (limited to 'drivers/spi/spi-dw-mid.c')
-rw-r--r--drivers/spi/spi-dw-mid.c69
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);