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spi: dw-mid: move to use core SPI DMA mappings
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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>
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Andy Shevchenko authored and Mark Brown committed Mar 9, 2015
1 parent 4d5ac1e commit f89a6d8
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Showing 3 changed files with 43 additions and 66 deletions.
52 changes: 30 additions & 22 deletions drivers/spi/spi-dw-mid.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand All @@ -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;
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand All @@ -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)
Expand All @@ -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;
Expand All @@ -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)
Expand All @@ -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);

Expand All @@ -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) {
Expand Down Expand Up @@ -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,
};
Expand Down
40 changes: 7 additions & 33 deletions drivers/spi/spi-dw.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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;
Expand All @@ -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;
}
Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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;
}
}

Expand Down
17 changes: 6 additions & 11 deletions drivers/spi/spi-dw.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
};

Expand All @@ -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 */
Expand Down Expand Up @@ -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);
};

Expand Down

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