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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.c145
1 files changed, 69 insertions, 76 deletions
diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 1d237e93a289..d5157b2222ce 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -419,16 +419,13 @@ static void omap2_mcspi_tx_dma(struct spi_device *spi,
if (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);
+ tx = dmaengine_prep_slave_sg(mcspi_dma->dma_tx, xfer->tx_sg.sgl,
+ xfer->tx_sg.nents,
+ DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_tx_callback;
tx->callback_param = spi;
@@ -449,7 +446,10 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
{
struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
- unsigned int count, dma_count;
+ unsigned int count, transfer_reduction = 0;
+ struct scatterlist *sg_out[2];
+ int nb_sizes = 0, out_mapped_nents[2], ret, x;
+ size_t sizes[2];
u32 l;
int elements = 0;
int word_len, element_count;
@@ -457,10 +457,14 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
mcspi = spi_master_get_devdata(spi->master);
mcspi_dma = &mcspi->dma_channels[spi->chip_select];
count = xfer->len;
- dma_count = xfer->len;
+ /*
+ * In the "End-of-Transfer Procedure" section for DMA RX in OMAP35x TRM
+ * it mentions reducing DMA transfer length by one element in master
+ * normal mode.
+ */
if (mcspi->fifo_depth == 0)
- dma_count -= es;
+ transfer_reduction = es;
word_len = cs->word_len;
l = mcspi_cached_chconf0(spi);
@@ -474,20 +478,46 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
if (mcspi_dma->dma_rx) {
struct dma_async_tx_descriptor *tx;
- struct scatterlist sg;
dmaengine_slave_config(mcspi_dma->dma_rx, &cfg);
+ /*
+ * Reduce DMA transfer length by one more if McSPI is
+ * configured in turbo mode.
+ */
if ((l & OMAP2_MCSPI_CHCONF_TURBO) && mcspi->fifo_depth == 0)
- dma_count -= es;
+ transfer_reduction += es;
+
+ if (transfer_reduction) {
+ /* Split sgl into two. The second sgl won't be used. */
+ sizes[0] = count - transfer_reduction;
+ sizes[1] = transfer_reduction;
+ nb_sizes = 2;
+ } else {
+ /*
+ * Don't bother splitting the sgl. This essentially
+ * clones the original sgl.
+ */
+ sizes[0] = count;
+ nb_sizes = 1;
+ }
+
+ ret = sg_split(xfer->rx_sg.sgl, xfer->rx_sg.nents,
+ 0, nb_sizes,
+ sizes,
+ sg_out, out_mapped_nents,
+ GFP_KERNEL);
- sg_init_table(&sg, 1);
- sg_dma_address(&sg) = xfer->rx_dma;
- sg_dma_len(&sg) = dma_count;
+ if (ret < 0) {
+ dev_err(&spi->dev, "sg_split failed\n");
+ return 0;
+ }
- tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx, &sg, 1,
- DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT |
- DMA_CTRL_ACK);
+ tx = dmaengine_prep_slave_sg(mcspi_dma->dma_rx,
+ sg_out[0],
+ out_mapped_nents[0],
+ DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (tx) {
tx->callback = omap2_mcspi_rx_callback;
tx->callback_param = spi;
@@ -501,12 +531,17 @@ omap2_mcspi_rx_dma(struct spi_device *spi, struct spi_transfer *xfer,
omap2_mcspi_set_dma_req(spi, 1, 1);
wait_for_completion(&mcspi_dma->dma_rx_completion);
- dma_unmap_single(mcspi->dev, xfer->rx_dma, count,
- DMA_FROM_DEVICE);
+
+ for (x = 0; x < nb_sizes; x++)
+ kfree(sg_out[x]);
if (mcspi->fifo_depth > 0)
return count;
+ /*
+ * Due to the DMA transfer length reduction the missing bytes must
+ * be read manually to receive all of the expected data.
+ */
omap2_mcspi_set_enable(spi, 0);
elements = element_count - 1;
@@ -615,8 +650,6 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
if (tx != NULL) {
wait_for_completion(&mcspi_dma->dma_tx_completion);
- dma_unmap_single(mcspi->dev, xfer->tx_dma, xfer->len,
- DMA_TO_DEVICE);
if (mcspi->fifo_depth > 0) {
irqstat_reg = mcspi->base + OMAP2_MCSPI_IRQSTATUS;
@@ -1074,8 +1107,9 @@ static void omap2_mcspi_cleanup(struct spi_device *spi)
gpio_free(spi->cs_gpio);
}
-static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
- struct spi_device *spi, struct spi_transfer *t)
+static int omap2_mcspi_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *t)
{
/* We only enable one channel at a time -- the one whose message is
@@ -1085,7 +1119,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
* chipselect with the FORCE bit ... CS != channel enable.
*/
- struct spi_master *master;
+ struct omap2_mcspi *mcspi;
struct omap2_mcspi_dma *mcspi_dma;
struct omap2_mcspi_cs *cs;
struct omap2_mcspi_device_config *cd;
@@ -1093,7 +1127,7 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
int status = 0;
u32 chconf;
- master = spi->master;
+ mcspi = spi_master_get_devdata(master);
mcspi_dma = mcspi->dma_channels + spi->chip_select;
cs = spi->controller_state;
cd = spi->controller_data;
@@ -1153,7 +1187,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
unsigned count;
if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
- (t->len >= DMA_MIN_BYTES))
+ master->cur_msg_mapped &&
+ master->can_dma(master, spi, t))
omap2_mcspi_set_fifo(spi, t, 1);
omap2_mcspi_set_enable(spi, 1);
@@ -1164,7 +1199,8 @@ static int omap2_mcspi_work_one(struct omap2_mcspi *mcspi,
+ OMAP2_MCSPI_TX0);
if ((mcspi_dma->dma_rx && mcspi_dma->dma_tx) &&
- (t->len >= DMA_MIN_BYTES))
+ master->cur_msg_mapped &&
+ master->can_dma(master, spi, t))
count = omap2_mcspi_txrx_dma(spi, t);
else
count = omap2_mcspi_txrx_pio(spi, t);
@@ -1233,55 +1269,11 @@ static int omap2_mcspi_prepare_message(struct spi_master *master,
return 0;
}
-static int omap2_mcspi_transfer_one(struct spi_master *master,
- struct spi_device *spi, struct spi_transfer *t)
+static bool omap2_mcspi_can_dma(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
{
- struct omap2_mcspi *mcspi;
- struct omap2_mcspi_dma *mcspi_dma;
- const void *tx_buf = t->tx_buf;
- void *rx_buf = t->rx_buf;
- unsigned len = t->len;
-
- mcspi = spi_master_get_devdata(master);
- mcspi_dma = mcspi->dma_channels + spi->chip_select;
-
- if ((len && !(rx_buf || tx_buf))) {
- dev_dbg(mcspi->dev, "transfer: %d Hz, %d %s%s, %d bpw\n",
- t->speed_hz,
- len,
- tx_buf ? "tx" : "",
- rx_buf ? "rx" : "",
- t->bits_per_word);
- return -EINVAL;
- }
-
- if (len < DMA_MIN_BYTES)
- goto skip_dma_map;
-
- if (mcspi_dma->dma_tx && tx_buf != NULL) {
- t->tx_dma = dma_map_single(mcspi->dev, (void *) tx_buf,
- len, DMA_TO_DEVICE);
- if (dma_mapping_error(mcspi->dev, t->tx_dma)) {
- dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
- 'T', len);
- return -EINVAL;
- }
- }
- if (mcspi_dma->dma_rx && rx_buf != NULL) {
- t->rx_dma = dma_map_single(mcspi->dev, rx_buf, t->len,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(mcspi->dev, t->rx_dma)) {
- dev_dbg(mcspi->dev, "dma %cX %d bytes error\n",
- 'R', len);
- if (tx_buf != NULL)
- dma_unmap_single(mcspi->dev, t->tx_dma,
- len, DMA_TO_DEVICE);
- return -EINVAL;
- }
- }
-
-skip_dma_map:
- return omap2_mcspi_work_one(mcspi, spi, t);
+ return (xfer->len >= DMA_MIN_BYTES);
}
static int omap2_mcspi_master_setup(struct omap2_mcspi *mcspi)
@@ -1361,6 +1353,7 @@ static int omap2_mcspi_probe(struct platform_device *pdev)
master->setup = omap2_mcspi_setup;
master->auto_runtime_pm = true;
master->prepare_message = omap2_mcspi_prepare_message;
+ master->can_dma = omap2_mcspi_can_dma;
master->transfer_one = omap2_mcspi_transfer_one;
master->set_cs = omap2_mcspi_set_cs;
master->cleanup = omap2_mcspi_cleanup;
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-16 12:38:20 +0000