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path: root/drivers/spi/spi-omap2-mcspi.c
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Diffstat (limited to 'drivers/spi/spi-omap2-mcspi.c')
-rw-r--r--drivers/spi/spi-omap2-mcspi.c181
1 files changed, 150 insertions, 31 deletions
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 0c73dd4f43a0..9fdb7a9ae03f 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -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>
@@ -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>
@@ -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;
@@ -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)
{
@@ -314,6 +344,9 @@ 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];
@@ -321,6 +354,71 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
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;
@@ -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,
@@ -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--;
@@ -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);
}
@@ -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)) {
@@ -725,32 +832,12 @@ 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)
@@ -758,17 +845,43 @@ 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)) {
@@ -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;
}
@@ -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;
@@ -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;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-17 00:31:53 +0000