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yaml
---
r: 321128
b: refs/heads/master
c: 53741ed
h: refs/heads/master
v: v3
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Russell King committed Jul 31, 2012
1 parent e102f1d commit 60cb793
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Showing 2 changed files with 151 additions and 32 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 8a23fa1b95b2e3878c16dcc4e18976bc46dd970b
refs/heads/master: 53741ed8f0a3fc646576b6d7adf563f403ba6c03
181 changes: 150 additions & 31 deletions trunk/drivers/spi/spi-omap2-mcspi.c
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Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,8 @@
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#define USE_DMA_ENGINE_RX
#define USE_DMA_ENGINE_TX

#include <linux/kernel.h>
#include <linux/init.h>
Expand All @@ -28,6 +30,8 @@
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/omap-dma.h>
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
Expand Down Expand Up @@ -93,6 +97,8 @@

/* We have 2 DMA channels per CS, one for RX and one for TX */
struct omap2_mcspi_dma {
struct dma_chan *dma_tx;
struct dma_chan *dma_rx;
int dma_tx_channel;
int dma_rx_channel;

Expand Down Expand Up @@ -300,6 +306,30 @@ static int mcspi_wait_for_reg_bit(void __iomem *reg, unsigned long bit)
return 0;
}

static void omap2_mcspi_rx_callback(void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];

complete(&mcspi_dma->dma_rx_completion);

/* We must disable the DMA RX request */
omap2_mcspi_set_dma_req(spi, 1, 0);
}

static void omap2_mcspi_tx_callback(void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master);
struct omap2_mcspi_dma *mcspi_dma = &mcspi->dma_channels[spi->chip_select];

complete(&mcspi_dma->dma_tx_completion);

/* We must disable the DMA TX request */
omap2_mcspi_set_dma_req(spi, 0, 0);
}

static unsigned
omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
{
Expand All @@ -314,13 +344,81 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
u8 * rx;
const u8 * tx;
void __iomem *chstat_reg;
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);

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) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;

dmaengine_slave_config(mcspi_dma->dma_tx, &cfg);

sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->tx_dma;
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);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
dmaengine_submit(tx);
} else {
/* FIXME: fall back to PIO? */
}
}

if (xfer->rx_buf && mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
struct scatterlist sg;
size_t len = xfer->len - es;

dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);

if (l & OMAP2_MCSPI_CHCONF_TURBO)
len -= es;

sg_init_table(&sg, 1);
sg_dma_address(&sg) = xfer->rx_dma;
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);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
dmaengine_submit(tx);
} else {
/* FIXME: fall back to PIO? */
}
}

count = xfer->len;
c = count;
word_len = cs->word_len;
Expand All @@ -342,7 +440,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
element_count = count >> 2;
}

if (tx != NULL) {
if (tx != NULL && mcspi_dma->dma_tx_channel != -1) {
omap_set_dma_transfer_params(mcspi_dma->dma_tx_channel,
data_type, element_count, 1,
OMAP_DMA_SYNC_ELEMENT,
Expand All @@ -357,7 +455,7 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
xfer->tx_dma, 0, 0);
}

if (rx != NULL) {
if (rx != NULL && mcspi_dma->dma_rx_channel != -1) {
elements = element_count - 1;
if (l & OMAP2_MCSPI_CHCONF_TURBO)
elements--;
Expand All @@ -377,12 +475,18 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
}

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

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

Expand All @@ -406,7 +510,10 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
dma_unmap_single(&spi->dev, xfer->rx_dma, count, DMA_FROM_DEVICE);
omap2_mcspi_set_enable(spi, 0);

elements = element_count - 1;

if (l & OMAP2_MCSPI_CHCONF_TURBO) {
elements--;

if (likely(mcspi_read_cs_reg(spi, OMAP2_MCSPI_CHSTAT0)
& OMAP2_MCSPI_CHSTAT_RXS)) {
Expand Down Expand Up @@ -725,50 +832,56 @@ static int omap2_mcspi_setup_transfer(struct spi_device *spi,

static void omap2_mcspi_dma_rx_callback(int lch, u16 ch_status, void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;

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

complete(&mcspi_dma->dma_rx_completion);

/* We must disable the DMA RX request */
omap2_mcspi_set_dma_req(spi, 1, 0);
omap2_mcspi_rx_callback(data);
}

static void omap2_mcspi_dma_tx_callback(int lch, u16 ch_status, void *data)
{
struct spi_device *spi = data;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;

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

complete(&mcspi_dma->dma_tx_completion);

/* We must disable the DMA TX request */
omap2_mcspi_set_dma_req(spi, 0, 0);
omap2_mcspi_tx_callback(data);
}

static int omap2_mcspi_request_dma(struct spi_device *spi)
{
struct spi_master *master = spi->master;
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
dma_cap_mask_t mask;
unsigned sig;

mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;

init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);

dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
#ifdef USE_DMA_ENGINE_RX
sig = mcspi_dma->dma_rx_sync_dev;
mcspi_dma->dma_rx = dma_request_channel(mask, omap_dma_filter_fn, &sig);
if (!mcspi_dma->dma_rx) {
dev_err(&spi->dev, "no RX DMA engine channel for McSPI\n");
return -EAGAIN;
}
#else
if (omap_request_dma(mcspi_dma->dma_rx_sync_dev, "McSPI RX",
omap2_mcspi_dma_rx_callback, spi,
&mcspi_dma->dma_rx_channel)) {
dev_err(&spi->dev, "no RX DMA channel for McSPI\n");
return -EAGAIN;
}
#endif

#ifdef USE_DMA_ENGINE_TX
sig = mcspi_dma->dma_tx_sync_dev;
mcspi_dma->dma_tx = dma_request_channel(mask, omap_dma_filter_fn, &sig);
if (!mcspi_dma->dma_tx) {
dev_err(&spi->dev, "no TX DMA engine channel for McSPI\n");
dma_release_channel(mcspi_dma->dma_rx);
mcspi_dma->dma_rx = NULL;
return -EAGAIN;
}
#else
if (omap_request_dma(mcspi_dma->dma_tx_sync_dev, "McSPI TX",
omap2_mcspi_dma_tx_callback, spi,
&mcspi_dma->dma_tx_channel)) {
Expand All @@ -777,9 +890,7 @@ static int omap2_mcspi_request_dma(struct spi_device *spi)
dev_err(&spi->dev, "no TX DMA channel for McSPI\n");
return -EAGAIN;
}

init_completion(&mcspi_dma->dma_rx_completion);
init_completion(&mcspi_dma->dma_tx_completion);
#endif

return 0;
}
Expand Down Expand Up @@ -812,8 +923,8 @@ static int omap2_mcspi_setup(struct spi_device *spi)
list_add_tail(&cs->node, &ctx->cs);
}

if (mcspi_dma->dma_rx_channel == -1
|| mcspi_dma->dma_tx_channel == -1) {
if ((!mcspi_dma->dma_rx && mcspi_dma->dma_rx_channel == -1) ||
(!mcspi_dma->dma_tx && mcspi_dma->dma_tx_channel == -1)) {
ret = omap2_mcspi_request_dma(spi);
if (ret < 0)
return ret;
Expand Down Expand Up @@ -848,6 +959,14 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
if (spi->chip_select < spi->master->num_chipselect) {
mcspi_dma = &mcspi->dma_channels[spi->chip_select];

if (mcspi_dma->dma_rx) {
dma_release_channel(mcspi_dma->dma_rx);
mcspi_dma->dma_rx = NULL;
}
if (mcspi_dma->dma_tx) {
dma_release_channel(mcspi_dma->dma_tx);
mcspi_dma->dma_tx = NULL;
}
if (mcspi_dma->dma_rx_channel != -1) {
omap_free_dma(mcspi_dma->dma_rx_channel);
mcspi_dma->dma_rx_channel = -1;
Expand Down

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