[PATCH v2 3/3] spi: spi-davinci: convert to DMA engine API
Matt Porter
mporter at ti.com
Tue Aug 21 14:43:09 EDT 2012
Removes use of the DaVinci EDMA private DMA API and replaces
it with use of the DMA engine API.
Signed-off-by: Matt Porter <mporter at ti.com>
---
drivers/spi/spi-davinci.c | 292 ++++++++++++++++++++-------------------------
1 file changed, 130 insertions(+), 162 deletions(-)
diff --git a/drivers/spi/spi-davinci.c b/drivers/spi/spi-davinci.c
index 9b2901f..c1ec52d 100644
--- a/drivers/spi/spi-davinci.c
+++ b/drivers/spi/spi-davinci.c
@@ -25,13 +25,14 @@
#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/clk.h>
+#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
+#include <linux/edma.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/slab.h>
#include <mach/spi.h>
-#include <mach/edma.h>
#define SPI_NO_RESOURCE ((resource_size_t)-1)
@@ -113,14 +114,6 @@
#define SPIDEF 0x4c
#define SPIFMT0 0x50
-/* We have 2 DMA channels per CS, one for RX and one for TX */
-struct davinci_spi_dma {
- int tx_channel;
- int rx_channel;
- int dummy_param_slot;
- enum dma_event_q eventq;
-};
-
/* SPI Controller driver's private data. */
struct davinci_spi {
struct spi_bitbang bitbang;
@@ -134,11 +127,14 @@ struct davinci_spi {
const void *tx;
void *rx;
-#define SPI_TMP_BUFSZ (SMP_CACHE_BYTES + 1)
- u8 rx_tmp_buf[SPI_TMP_BUFSZ];
int rcount;
int wcount;
- struct davinci_spi_dma dma;
+
+ struct dma_chan *dma_rx;
+ struct dma_chan *dma_tx;
+ int dma_rx_chnum;
+ int dma_tx_chnum;
+
struct davinci_spi_platform_data *pdata;
void (*get_rx)(u32 rx_data, struct davinci_spi *);
@@ -496,21 +492,23 @@ out:
return errors;
}
-static void davinci_spi_dma_callback(unsigned lch, u16 status, void *data)
+static void davinci_spi_dma_rx_callback(void *data)
{
- struct davinci_spi *dspi = data;
- struct davinci_spi_dma *dma = &dspi->dma;
+ struct davinci_spi *dspi = (struct davinci_spi *)data;
- edma_stop(lch);
+ dspi->rcount = 0;
- if (status == DMA_COMPLETE) {
- if (lch == dma->rx_channel)
- dspi->rcount = 0;
- if (lch == dma->tx_channel)
- dspi->wcount = 0;
- }
+ if (!dspi->wcount && !dspi->rcount)
+ complete(&dspi->done);
+}
- if ((!dspi->wcount && !dspi->rcount) || (status != DMA_COMPLETE))
+static void davinci_spi_dma_tx_callback(void *data)
+{
+ struct davinci_spi *dspi = (struct davinci_spi *)data;
+
+ dspi->wcount = 0;
+
+ if (!dspi->wcount && !dspi->rcount)
complete(&dspi->done);
}
@@ -526,20 +524,20 @@ static void davinci_spi_dma_callback(unsigned lch, u16 status, void *data)
static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct davinci_spi *dspi;
- int data_type, ret;
+ int data_type, ret = -ENOMEM;
u32 tx_data, spidat1;
u32 errors = 0;
struct davinci_spi_config *spicfg;
struct davinci_spi_platform_data *pdata;
unsigned uninitialized_var(rx_buf_count);
- struct device *sdev;
+ void *dummy_buf = NULL;
+ struct scatterlist sg_rx, sg_tx;
dspi = spi_master_get_devdata(spi->master);
pdata = dspi->pdata;
spicfg = (struct davinci_spi_config *)spi->controller_data;
if (!spicfg)
spicfg = &davinci_spi_default_cfg;
- sdev = dspi->bitbang.master->dev.parent;
/* convert len to words based on bits_per_word */
data_type = dspi->bytes_per_word[spi->chip_select];
@@ -567,112 +565,83 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
spidat1 |= tx_data & 0xFFFF;
iowrite32(spidat1, dspi->base + SPIDAT1);
} else {
- struct davinci_spi_dma *dma;
- unsigned long tx_reg, rx_reg;
- struct edmacc_param param;
- void *rx_buf;
- int b, c;
-
- dma = &dspi->dma;
-
- tx_reg = (unsigned long)dspi->pbase + SPIDAT1;
- rx_reg = (unsigned long)dspi->pbase + SPIBUF;
-
- /*
- * Transmit DMA setup
- *
- * If there is transmit data, map the transmit buffer, set it
- * as the source of data and set the source B index to data
- * size. If there is no transmit data, set the transmit register
- * as the source of data, and set the source B index to zero.
- *
- * The destination is always the transmit register itself. And
- * the destination never increments.
- */
-
- if (t->tx_buf) {
- t->tx_dma = dma_map_single(&spi->dev, (void *)t->tx_buf,
- t->len, DMA_TO_DEVICE);
- if (dma_mapping_error(&spi->dev, t->tx_dma)) {
- dev_dbg(sdev, "Unable to DMA map %d bytes"
- "TX buffer\n", t->len);
- return -ENOMEM;
- }
- }
-
- /*
- * If number of words is greater than 65535, then we need
- * to configure a 3 dimension transfer. Use the BCNTRLD
- * feature to allow for transfers that aren't even multiples
- * of 65535 (or any other possible b size) by first transferring
- * the remainder amount then grabbing the next N blocks of
- * 65535 words.
- */
-
- c = dspi->wcount / (SZ_64K - 1); /* N 65535 Blocks */
- b = dspi->wcount - c * (SZ_64K - 1); /* Remainder */
- if (b)
- c++;
+ struct dma_slave_config dma_rx_conf = {
+ .direction = DMA_DEV_TO_MEM,
+ .src_addr = (unsigned long)dspi->pbase + SPIBUF,
+ .src_addr_width = data_type,
+ .src_maxburst = 1,
+ };
+ struct dma_slave_config dma_tx_conf = {
+ .direction = DMA_MEM_TO_DEV,
+ .dst_addr = (unsigned long)dspi->pbase + SPIDAT1,
+ .dst_addr_width = data_type,
+ .dst_maxburst = 1,
+ };
+ struct dma_async_tx_descriptor *rxdesc;
+ struct dma_async_tx_descriptor *txdesc;
+ void *buf;
+
+ dummy_buf = kzalloc(t->len, GFP_KERNEL);
+ if (!dummy_buf)
+ goto err_alloc_dummy_buf;
+
+ dmaengine_slave_config(dspi->dma_rx, &dma_rx_conf);
+ dmaengine_slave_config(dspi->dma_tx, &dma_tx_conf);
+
+ sg_init_table(&sg_rx, 1);
+ if (!t->rx_buf)
+ buf = dummy_buf;
else
- b = SZ_64K - 1;
-
- param.opt = TCINTEN | EDMA_TCC(dma->tx_channel);
- param.src = t->tx_buf ? t->tx_dma : tx_reg;
- param.a_b_cnt = b << 16 | data_type;
- param.dst = tx_reg;
- param.src_dst_bidx = t->tx_buf ? data_type : 0;
- param.link_bcntrld = 0xffffffff;
- param.src_dst_cidx = t->tx_buf ? data_type : 0;
- param.ccnt = c;
- edma_write_slot(dma->tx_channel, ¶m);
- edma_link(dma->tx_channel, dma->dummy_param_slot);
-
- /*
- * Receive DMA setup
- *
- * If there is receive buffer, use it to receive data. If there
- * is none provided, use a temporary receive buffer. Set the
- * destination B index to 0 so effectively only one byte is used
- * in the temporary buffer (address does not increment).
- *
- * The source of receive data is the receive data register. The
- * source address never increments.
- */
-
- if (t->rx_buf) {
- rx_buf = t->rx_buf;
- rx_buf_count = t->len;
- } else {
- rx_buf = dspi->rx_tmp_buf;
- rx_buf_count = sizeof(dspi->rx_tmp_buf);
+ buf = t->rx_buf;
+ t->rx_dma = dma_map_single(&spi->dev, buf,
+ t->len, DMA_FROM_DEVICE);
+ if (!t->rx_dma) {
+ ret = -EFAULT;
+ goto err_rx_map;
}
+ sg_dma_address(&sg_rx) = t->rx_dma;
+ sg_dma_len(&sg_rx) = t->len;
- t->rx_dma = dma_map_single(&spi->dev, rx_buf, rx_buf_count,
- DMA_FROM_DEVICE);
- if (dma_mapping_error(&spi->dev, t->rx_dma)) {
- dev_dbg(sdev, "Couldn't DMA map a %d bytes RX buffer\n",
- rx_buf_count);
- if (t->tx_buf)
- dma_unmap_single(&spi->dev, t->tx_dma, t->len,
- DMA_TO_DEVICE);
- return -ENOMEM;
+ sg_init_table(&sg_tx, 1);
+ if (!t->tx_buf)
+ buf = dummy_buf;
+ else
+ buf = (void *)t->tx_buf;
+ t->tx_dma = dma_map_single(&spi->dev, buf,
+ t->len, DMA_FROM_DEVICE);
+ if (!t->tx_dma) {
+ ret = -EFAULT;
+ goto err_tx_map;
}
-
- param.opt = TCINTEN | EDMA_TCC(dma->rx_channel);
- param.src = rx_reg;
- param.a_b_cnt = b << 16 | data_type;
- param.dst = t->rx_dma;
- param.src_dst_bidx = (t->rx_buf ? data_type : 0) << 16;
- param.link_bcntrld = 0xffffffff;
- param.src_dst_cidx = (t->rx_buf ? data_type : 0) << 16;
- param.ccnt = c;
- edma_write_slot(dma->rx_channel, ¶m);
+ sg_dma_address(&sg_tx) = t->tx_dma;
+ sg_dma_len(&sg_tx) = t->len;
+
+ rxdesc = dmaengine_prep_slave_sg(dspi->dma_rx,
+ &sg_rx, 1, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!rxdesc)
+ goto err_desc;
+
+ txdesc = dmaengine_prep_slave_sg(dspi->dma_tx,
+ &sg_tx, 1, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc)
+ goto err_desc;
+
+ rxdesc->callback = davinci_spi_dma_rx_callback;
+ rxdesc->callback_param = (void *)dspi;
+ txdesc->callback = davinci_spi_dma_tx_callback;
+ txdesc->callback_param = (void *)dspi;
if (pdata->cshold_bug)
iowrite16(spidat1 >> 16, dspi->base + SPIDAT1 + 2);
- edma_start(dma->rx_channel);
- edma_start(dma->tx_channel);
+ dmaengine_submit(rxdesc);
+ dmaengine_submit(txdesc);
+
+ dma_async_issue_pending(dspi->dma_rx);
+ dma_async_issue_pending(dspi->dma_tx);
+
set_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
}
@@ -690,15 +659,13 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
clear_io_bits(dspi->base + SPIINT, SPIINT_MASKALL);
if (spicfg->io_type == SPI_IO_TYPE_DMA) {
-
- if (t->tx_buf)
- dma_unmap_single(&spi->dev, t->tx_dma, t->len,
- DMA_TO_DEVICE);
-
- dma_unmap_single(&spi->dev, t->rx_dma, rx_buf_count,
- DMA_FROM_DEVICE);
-
clear_io_bits(dspi->base + SPIINT, SPIINT_DMA_REQ_EN);
+
+ dma_unmap_single(&spi->dev, t->rx_dma,
+ t->len, DMA_FROM_DEVICE);
+ dma_unmap_single(&spi->dev, t->tx_dma,
+ t->len, DMA_TO_DEVICE);
+ kfree(dummy_buf);
}
clear_io_bits(dspi->base + SPIGCR1, SPIGCR1_SPIENA_MASK);
@@ -716,11 +683,20 @@ static int davinci_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
}
if (dspi->rcount != 0 || dspi->wcount != 0) {
- dev_err(sdev, "SPI data transfer error\n");
+ dev_err(&spi->dev, "SPI data transfer error\n");
return -EIO;
}
return t->len;
+
+err_desc:
+ dma_unmap_single(&spi->dev, t->tx_dma, t->len, DMA_TO_DEVICE);
+err_tx_map:
+ dma_unmap_single(&spi->dev, t->rx_dma, t->len, DMA_FROM_DEVICE);
+err_rx_map:
+ kfree(dummy_buf);
+err_alloc_dummy_buf:
+ return ret;
}
/**
@@ -751,39 +727,33 @@ static irqreturn_t davinci_spi_irq(s32 irq, void *data)
static int davinci_spi_request_dma(struct davinci_spi *dspi)
{
+ dma_cap_mask_t mask;
+ struct device *sdev = dspi->bitbang.master->dev.parent;
int r;
- struct davinci_spi_dma *dma = &dspi->dma;
- r = edma_alloc_channel(dma->rx_channel, davinci_spi_dma_callback, dspi,
- dma->eventq);
- if (r < 0) {
- pr_err("Unable to request DMA channel for SPI RX\n");
- r = -EAGAIN;
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ dspi->dma_rx = dma_request_channel(mask, edma_filter_fn,
+ &dspi->dma_rx_chnum);
+ if (!dspi->dma_rx) {
+ dev_err(sdev, "request RX DMA channel failed\n");
+ r = -ENODEV;
goto rx_dma_failed;
}
- r = edma_alloc_channel(dma->tx_channel, davinci_spi_dma_callback, dspi,
- dma->eventq);
- if (r < 0) {
- pr_err("Unable to request DMA channel for SPI TX\n");
- r = -EAGAIN;
+ dspi->dma_tx = dma_request_channel(mask, edma_filter_fn,
+ &dspi->dma_tx_chnum);
+ if (!dspi->dma_tx) {
+ dev_err(sdev, "request TX DMA channel failed\n");
+ r = -ENODEV;
goto tx_dma_failed;
}
- r = edma_alloc_slot(EDMA_CTLR(dma->tx_channel), EDMA_SLOT_ANY);
- if (r < 0) {
- pr_err("Unable to request SPI TX DMA param slot\n");
- r = -EAGAIN;
- goto param_failed;
- }
- dma->dummy_param_slot = r;
- edma_link(dma->dummy_param_slot, dma->dummy_param_slot);
-
return 0;
-param_failed:
- edma_free_channel(dma->tx_channel);
+
tx_dma_failed:
- edma_free_channel(dma->rx_channel);
+ dma_release_channel(dspi->dma_rx);
rx_dma_failed:
return r;
}
@@ -898,9 +868,8 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
dspi->bitbang.txrx_bufs = davinci_spi_bufs;
if (dma_rx_chan != SPI_NO_RESOURCE &&
dma_tx_chan != SPI_NO_RESOURCE) {
- dspi->dma.rx_channel = dma_rx_chan;
- dspi->dma.tx_channel = dma_tx_chan;
- dspi->dma.eventq = pdata->dma_event_q;
+ dspi->dma_rx_chnum = dma_rx_chan;
+ dspi->dma_tx_chnum = dma_tx_chan;
ret = davinci_spi_request_dma(dspi);
if (ret)
@@ -955,9 +924,8 @@ static int __devinit davinci_spi_probe(struct platform_device *pdev)
return ret;
free_dma:
- edma_free_channel(dspi->dma.tx_channel);
- edma_free_channel(dspi->dma.rx_channel);
- edma_free_slot(dspi->dma.dummy_param_slot);
+ dma_release_channel(dspi->dma_rx);
+ dma_release_channel(dspi->dma_tx);
free_clk:
clk_disable(dspi->clk);
clk_put(dspi->clk);
--
1.7.9.5
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