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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>
This commit is contained in:
Andy Shevchenko 2014-10-28 18:25:01 +02:00 committed by Mark Brown
parent b7a40242c8
commit a5c2db964d
1 changed files with 48 additions and 21 deletions
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69
drivers/spi/spi-dw-mid.c
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@ -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;
struct dma_slave_config txconf;
struct dma_async_tx_descriptor *txdesc;
/* 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);
}
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);