Skip to content

Commit

Permalink
spi: omap2-mcspi: Cleanup the omap2_mcspi_txrx_dma function
Browse files Browse the repository at this point in the history 
Currently in omap2_mcspi_txrx_dma the tx and the rx support is
interleaved. Make the rx related code in omap2_mcspi_rx_dma
and the tx related code omap2_mcspi_tx_dma and call the functions.

While at it remove the braces in the if statements which has only
one line.
Also fix ["foo * bar" to "foo *bar"] warn for the rx and tx variables.

Only a cleanup no functional change.

Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com>
Tested-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
  • Loading branch information
Shubhrajyoti D authored and Mark Brown committed Sep 12, 2012
1 parent ac2cb30 commit d7b4394
Showing 1 changed file with 144 additions and 112 deletions.
256 changes: 144 additions & 112 deletions drivers/spi/spi-omap2-mcspi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -315,49 +315,27 @@ static void omap2_mcspi_tx_callback(void *data)
omap2_mcspi_set_dma_req(spi, 0, 0);
}

static unsigned
omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
static void omap2_mcspi_tx_dma(struct spi_device *spi,
struct spi_transfer *xfer,
struct dma_slave_config cfg)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
int word_len, element_count;
int elements = 0;
u32 l;
u8 * rx;
const u8 * tx;
void __iomem *chstat_reg;
struct dma_slave_config cfg;
enum dma_slave_buswidth width;
unsigned es;
struct omap2_mcspi_cs *cs = spi->controller_state;

mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
l = mcspi_cached_chconf0(spi);
count = xfer->len;

rx = xfer->rx_buf;
tx = xfer->tx_buf;
chstat_reg = cs->base + OMAP2_MCSPI_CHSTAT0;

if (cs->word_len <= 8) {
width = DMA_SLAVE_BUSWIDTH_1_BYTE;
es = 1;
} else if (cs->word_len <= 16) {
width = DMA_SLAVE_BUSWIDTH_2_BYTES;
es = 2;
} else {
width = DMA_SLAVE_BUSWIDTH_4_BYTES;
es = 4;
}

memset(&cfg, 0, sizeof(cfg));
cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
cfg.src_addr_width = width;
cfg.dst_addr_width = width;
cfg.src_maxburst = 1;
cfg.dst_maxburst = 1;

if (xfer->tx_buf && mcspi_dma->dma_tx) {
if (mcspi_dma->dma_tx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;

Expand All @@ -368,7 +346,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
sg_dma_len(&sg) = xfer->len;

tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, &sg, 1,
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
Expand All @@ -377,8 +355,50 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
/* FIXME: fall back to PIO? */
}
}
dma_async_issue_pending(mcspi_dma->dma_tx);
omap2_mcspi_set_dma_req(spi, 0, 1);

if (xfer->rx_buf && mcspi_dma->dma_rx) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
DMA_TO_DEVICE);

/* for TX_ONLY mode, be sure all words have shifted out */
if (rx == NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0)
dev_err(&spi->dev, "TXS timed out\n");
else if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_EOT) < 0)
dev_err(&spi->dev, "EOT timed out\n");
}
}

static unsigned
omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
struct dma_slave_config cfg,
unsigned es)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
u32 l;
int elements = 0;
int word_len, element_count;
struct omap2_mcspi_cs *cs = spi->controller_state;
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
count = xfer->len;
word_len = cs->word_len;
l = mcspi_cached_chconf0(spi);

if (word_len <= 8)
element_count = count;
else if (word_len <= 16)
element_count = count >> 1;
else /* word_len <= 32 */
element_count = count >> 2;

if (mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
size_t len = xfer->len - es;
Expand All @@ -393,108 +413,120 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
sg_dma_len(&sg) = len;

tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
dmaengine_submit(tx);
} else {
/* FIXME: fall back to PIO? */
}
}

count = xfer->len;
word_len = cs->word_len;

rx = xfer->rx_buf;
tx = xfer->tx_buf;

if (word_len <= 8) {
element_count = count;
} else if (word_len <= 16) {
element_count = count >> 1;
} else /* word_len <= 32 */ {
element_count = count >> 2;
}

if (tx != NULL) {
dma_async_issue_pending(mcspi_dma->dma_tx);
omap2_mcspi_set_dma_req(spi, 0, 1);
}

if (rx != NULL) {
dma_async_issue_pending(mcspi_dma->dma_rx);
omap2_mcspi_set_dma_req(spi, 1, 1);
}

if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
dma_unmap_single(mcspi->dev, xfer->tx_dma, count,
DMA_TO_DEVICE);

/* for TX_ONLY mode, be sure all words have shifted out */
if (rx == NULL) {
if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_TXS) < 0)
dev_err(&spi->dev, "TXS timed out\n");
else if (mcspi_wait_for_reg_bit(chstat_reg,
OMAP2_MCSPI_CHSTAT_EOT) < 0)
dev_err(&spi->dev, "EOT timed out\n");
/* FIXME: fall back to PIO? */
}
}

if (rx != NULL) {
wait_for_completion(&mcspi_dma->dma_rx_completion);
dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
DMA_FROM_DEVICE);
omap2_mcspi_set_enable(spi, 0);
dma_async_issue_pending(mcspi_dma->dma_rx);
omap2_mcspi_set_dma_req(spi, 1, 1);

elements = element_count - 1;
wait_for_completion(&mcspi_dma->dma_rx_completion);
dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
DMA_FROM_DEVICE);
omap2_mcspi_set_enable(spi, 0);

if (l & OMAP2_MCSPI_CHCONF_TURBO) {
elements--;
elements = element_count - 1;

if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;

w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[elements++] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements++] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements++] = w;
} else {
dev_err(&spi->dev,
"DMA RX penultimate word empty");
count -= (word_len <= 8) ? 2 :
(word_len <= 16) ? 4 :
/* word_len <= 32 */ 8;
omap2_mcspi_set_enable(spi, 1);
return count;
}
}
if (l & OMAP2_MCSPI_CHCONF_TURBO) {
elements--;

if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;

w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[elements] = w;
((u8 *)xfer->rx_buf)[elements++] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements] = w;
((u16 *)xfer->rx_buf)[elements++] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements] = w;
((u32 *)xfer->rx_buf)[elements++] = w;
} else {
dev_err(&spi->dev, "DMA RX last word empty");
count -= (word_len <= 8) ? 1 :
(word_len <= 16) ? 2 :
/* word_len <= 32 */ 4;
dev_err(&spi->dev, "DMA RX penultimate word empty");
count -= (word_len <= 8) ? 2 :
(word_len <= 16) ? 4 :
/* word_len <= 32 */ 8;
omap2_mcspi_set_enable(spi, 1);
return count;
}
omap2_mcspi_set_enable(spi, 1);
}
if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
u32 w;

w = mcspi_read_cs_reg(spi, OMAP2_MCSPI_RX0);
if (word_len <= 8)
((u8 *)xfer->rx_buf)[elements] = w;
else if (word_len <= 16)
((u16 *)xfer->rx_buf)[elements] = w;
else /* word_len <= 32 */
((u32 *)xfer->rx_buf)[elements] = w;
} else {
dev_err(&spi->dev, "DMA RX last word empty");
count -= (word_len <= 8) ? 1 :
(word_len <= 16) ? 2 :
/* word_len <= 32 */ 4;
}
omap2_mcspi_set_enable(spi, 1);
return count;
}

static unsigned
omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_cs *cs = spi->controller_state;
struct omap2_mcspi_dma *mcspi_dma;
unsigned int count;
u32 l;
u8 *rx;
const u8 *tx;
struct dma_slave_config cfg;
enum dma_slave_buswidth width;
unsigned es;

mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
l = mcspi_cached_chconf0(spi);


if (cs->word_len <= 8) {
width = DMA_SLAVE_BUSWIDTH_1_BYTE;
es = 1;
} else if (cs->word_len <= 16) {
width = DMA_SLAVE_BUSWIDTH_2_BYTES;
es = 2;
} else {
width = DMA_SLAVE_BUSWIDTH_4_BYTES;
es = 4;
}

memset(&cfg, 0, sizeof(cfg));
cfg.src_addr = cs->phys + OMAP2_MCSPI_RX0;
cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
cfg.src_addr_width = width;
cfg.dst_addr_width = width;
cfg.src_maxburst = 1;
cfg.dst_maxburst = 1;

rx = xfer->rx_buf;
tx = xfer->tx_buf;

count = xfer->len;

if (tx != NULL)
omap2_mcspi_tx_dma(spi, xfer, cfg);

if (rx != NULL)
return omap2_mcspi_rx_dma(spi, xfer, cfg, es);

return count;
}

Expand Down

0 comments on commit d7b4394

Please sign in to comment.