spi: spi-davinci: convert to DMA engine API
authorMatt Porter <mporter@ti.com>
Thu, 23 Aug 2012 01:09:36 +0000 (21:09 -0400)
committerVinod Koul <vinod.koul@linux.intel.com>
Sat, 1 Sep 2012 00:44:03 +0000 (06:14 +0530)
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@ti.com>
Tested-by: Tom Rini <trini@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
drivers/spi/spi-davinci.c

index 9b2901feaf78d4bf3783c9b8b3491f57bfdc2e83..c1ec52d467147858cd2a1ff23a9670fee3335655 100644 (file)
 #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)
 
 #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, &param);
-               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, &param);
+               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);