@@ -268,6 +268,7 @@ static struct spi_driver pl022_dummy_driver = {
.driver = {
.name = "spi-dummy",
.owner = THIS_MODULE,
+ .bus = &spi_bus_type,
},
.probe = pl022_dummy_probe,
.remove = __devexit_p(pl022_dummy_remove),
@@ -27,7 +27,6 @@
/*
* TODO:
* - add timeout on polled transfers
- * - add generic DMA framework support
*/
#include <linux/init.h>
@@ -45,6 +44,10 @@
#include <linux/amba/pl022.h>
#include <linux/io.h>
#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/amba/dma.h>
/*
* This macro is used to define some register default values.
@@ -365,6 +368,14 @@ struct pl022 {
enum ssp_reading read;
enum ssp_writing write;
u32 exp_fifo_level;
+ /* DMA settings */
+#ifdef CONFIG_DMADEVICES
+ struct dma_chan *dma_rx_channel;
+ struct dma_chan *dma_tx_channel;
+ struct sg_table sgt_rx;
+ struct sg_table sgt_tx;
+ char *dummypage;
+#endif
};
/**
@@ -699,6 +710,367 @@ static void *next_transfer(struct pl022 *pl022)
}
return STATE_DONE;
}
+
+/*
+ * This DMA functionality is only compiled in if we have
+ * access to the generic DMA devices/DMA engine.
+ */
+#ifdef CONFIG_DMADEVICES
+static void unmap_free_dma_scatter(struct pl022 *pl022)
+{
+ /* Unmap and free the SG tables */
+ dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+ dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+ sg_free_table(&pl022->sgt_rx);
+ sg_free_table(&pl022->sgt_tx);
+}
+
+static void dma_callback(void *data)
+{
+ struct pl022 *pl022 = data;
+ struct spi_message *msg = pl022->cur_msg;
+
+ /* Sync in RX buffer to CPU */
+ BUG_ON(!pl022->sgt_rx.sgl);
+ dma_sync_sg_for_cpu(&pl022->adev->dev,
+ pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents,
+ DMA_FROM_DEVICE);
+
+#ifdef VERBOSE_DEBUG
+ /*
+ * Optionally dump out buffers to inspect contents, this is
+ * good if you want to convince yourself that the loopback
+ * read/write contents are the same, when adopting to a new
+ * DMA engine.
+ */
+ {
+ struct scatterlist *sg;
+ unsigned int i;
+
+ for_each_sg(pl022->sgt_rx.sgl, sg, pl022->sgt_rx.nents, i) {
+ dev_dbg(&pl022->adev->dev, "SPI RX SG ENTRY: %d", i);
+ print_hex_dump(KERN_ERR, "SPI RX: ",
+ DUMP_PREFIX_OFFSET,
+ 16,
+ 1,
+ sg_virt(sg),
+ sg_dma_len(sg),
+ 1);
+ }
+ for_each_sg(pl022->sgt_tx.sgl, sg, pl022->sgt_tx.nents, i) {
+ dev_dbg(&pl022->adev->dev, "SPI TX SG ENTRY: %d", i);
+ print_hex_dump(KERN_ERR, "SPI TX: ",
+ DUMP_PREFIX_OFFSET,
+ 16,
+ 1,
+ sg_virt(sg),
+ sg_dma_len(sg),
+ 1);
+ }
+ }
+#endif
+
+ unmap_free_dma_scatter(pl022);
+
+ /* Update total bytes transfered */
+ msg->actual_length += pl022->cur_transfer->len;
+ if (pl022->cur_transfer->cs_change)
+ pl022->cur_chip->
+ cs_control(SSP_CHIP_DESELECT);
+
+ /* Move to next transfer */
+ msg->state = next_transfer(pl022);
+ tasklet_schedule(&pl022->pump_transfers);
+}
+
+static void setup_dma_scatter(struct pl022 *pl022,
+ void *buffer,
+ unsigned int length,
+ struct sg_table *sgtab)
+{
+ struct scatterlist *sg;
+ int bytesleft = length;
+ void *bufp = buffer;
+ int mapbytes;
+ int i;
+
+ if (buffer) {
+ for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+ /*
+ * If there are less bytes left than what fits
+ * in the current page (plus page alignment offset)
+ * we just feed in this, else we stuff in as much
+ * as we can.
+ */
+ if (bytesleft < (PAGE_SIZE - offset_in_page(bufp)))
+ mapbytes = bytesleft;
+ else
+ mapbytes = PAGE_SIZE - offset_in_page(bufp);
+ sg_set_page(sg, virt_to_page(bufp),
+ mapbytes, offset_in_page(bufp));
+ bufp += mapbytes;
+ bytesleft -= mapbytes;
+ dev_dbg(&pl022->adev->dev,
+ "set RX/TX target page @ %p, %d bytes, %d left\n",
+ bufp, mapbytes, bytesleft);
+ }
+ } else {
+ /* Map the dummy buffer on every page */
+ for_each_sg(sgtab->sgl, sg, sgtab->nents, i) {
+ if (bytesleft < PAGE_SIZE)
+ mapbytes = bytesleft;
+ else
+ mapbytes = PAGE_SIZE;
+ sg_set_page(sg, virt_to_page(pl022->dummypage),
+ mapbytes, 0);
+ bytesleft -= mapbytes;
+ dev_dbg(&pl022->adev->dev,
+ "set RX/TX to dummy page %d bytes, %d left\n",
+ mapbytes, bytesleft);
+
+ }
+ }
+ BUG_ON(bytesleft);
+}
+
+/**
+ * configure_dma - configures the channels for the next transfer
+ * @data: SSP driver's private data structure
+ *
+ */
+static int configure_dma(struct pl022 *pl022)
+{
+ struct amba_dma_channel_config rx_conf = {
+ .addr = SSP_DR(pl022->phybase),
+ .direction = DMA_FROM_DEVICE,
+ .maxburst = pl022->vendor->fifodepth >> 1,
+ };
+ struct amba_dma_channel_config tx_conf = {
+ .addr = SSP_DR(pl022->phybase),
+ .direction = DMA_TO_DEVICE,
+ .maxburst = pl022->vendor->fifodepth >> 1,
+ };
+ unsigned int pages;
+ int ret;
+ int sglen;
+ struct dma_chan *rxchan = pl022->dma_rx_channel;
+ struct dma_chan *txchan = pl022->dma_tx_channel;
+ struct dma_async_tx_descriptor *rxdesc;
+ struct dma_async_tx_descriptor *txdesc;
+
+ /* Check that the channels are available */
+ if (!rxchan || !txchan)
+ return -ENODEV;
+
+ switch (pl022->read) {
+ case READING_NULL:
+ /* Use the same as for writing */
+ rx_conf.addr_width = 0;
+ break;
+ case READING_U8:
+ rx_conf.addr_width = 1;
+ break;
+ case READING_U16:
+ rx_conf.addr_width = 2;
+ break;
+ case READING_U32:
+ rx_conf.addr_width = 4;
+ break;
+ }
+
+ switch (pl022->write) {
+ case WRITING_NULL:
+ /* Use the same as for reading */
+ tx_conf.addr_width = 0;
+ break;
+ case WRITING_U8:
+ tx_conf.addr_width = 1;
+ break;
+ case WRITING_U16:
+ tx_conf.addr_width = 2;
+ break;
+ case WRITING_U32:
+ tx_conf.addr_width = 4;
+ break;
+ }
+
+ /* SPI pecularity: we need to read and write the same width */
+ if (rx_conf.addr_width == 0)
+ rx_conf.addr_width = tx_conf.addr_width;
+ if (tx_conf.addr_width == 0)
+ tx_conf.addr_width = rx_conf.addr_width;
+ BUG_ON(rx_conf.addr_width != tx_conf.addr_width);
+
+ dma_set_ambaconfig(pl022->dma_rx_channel, &rx_conf);
+ dma_set_ambaconfig(pl022->dma_tx_channel, &tx_conf);
+
+ /* Create sglists for the transfers */
+ pages = (pl022->cur_transfer->len >> PAGE_SHIFT) + 1;
+ dev_dbg(&pl022->adev->dev, "using %d pages for transfer\n", pages);
+
+ ret = sg_alloc_table(&pl022->sgt_rx, pages, GFP_KERNEL);
+ if (ret)
+ goto err_alloc_rx_sg;
+
+ ret = sg_alloc_table(&pl022->sgt_tx, pages, GFP_KERNEL);
+ if (ret)
+ goto err_alloc_tx_sg;
+
+ /* Fill in the scatterlists for the RX+TX buffers */
+ setup_dma_scatter(pl022, pl022->rx,
+ pl022->cur_transfer->len, &pl022->sgt_rx);
+ setup_dma_scatter(pl022, pl022->tx,
+ pl022->cur_transfer->len, &pl022->sgt_tx);
+
+ /* Map DMA buffers */
+ sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents, DMA_FROM_DEVICE);
+ if (sglen != pages)
+ goto err_rx_sgmap;
+
+ sglen = dma_map_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+ if (sglen != pages)
+ goto err_tx_sgmap;
+
+ /* Synchronize the TX scatterlist, invalidate buffers, caches etc */
+ dma_sync_sg_for_device(&pl022->adev->dev,
+ pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents,
+ DMA_TO_DEVICE);
+
+ /* Send both scatterlists */
+ rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
+ pl022->sgt_rx.sgl,
+ pl022->sgt_rx.nents,
+ DMA_FROM_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!rxdesc)
+ goto err_rxdesc;
+
+ txdesc = txchan->device->device_prep_slave_sg(txchan,
+ pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents,
+ DMA_TO_DEVICE,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc)
+ goto err_txdesc;
+
+ /* Put the callback on the RX transfer only, that should finish last */
+ rxdesc->callback = dma_callback;
+ rxdesc->callback_param = pl022;
+
+ /* Submit and fire RX and TX with TX last so we're ready to read! */
+ rxdesc->tx_submit(rxdesc);
+ txdesc->tx_submit(txdesc);
+ rxchan->device->device_issue_pending(rxchan);
+ txchan->device->device_issue_pending(txchan);
+
+ return 0;
+
+err_txdesc:
+err_rxdesc:
+ dma_unmap_sg(&pl022->adev->dev, pl022->sgt_tx.sgl,
+ pl022->sgt_tx.nents, DMA_TO_DEVICE);
+err_tx_sgmap:
+ dma_unmap_sg(&pl022->adev->dev, pl022->sgt_rx.sgl,
+ pl022->sgt_tx.nents, DMA_FROM_DEVICE);
+err_rx_sgmap:
+ sg_free_table(&pl022->sgt_tx);
+err_alloc_tx_sg:
+ sg_free_table(&pl022->sgt_rx);
+err_alloc_rx_sg:
+ return -ENOMEM;
+}
+
+static int __init pl022_dma_probe(struct pl022 *pl022)
+{
+ dma_cap_mask_t mask;
+
+ /* Try to acquire a generic DMA engine slave channel */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ /*
+ * We need both RX and TX channels to do DMA, else do none
+ * of them.
+ */
+ pl022->dma_rx_channel = dma_request_channel(mask,
+ pl022->master_info->dma_filter,
+ pl022->master_info->dma_rx_param);
+ if (!pl022->dma_rx_channel) {
+ dev_err(&pl022->adev->dev, "no RX DMA channel!\n");
+ goto err_no_rxchan;
+ }
+
+ pl022->dma_tx_channel = dma_request_channel(mask,
+ pl022->master_info->dma_filter,
+ pl022->master_info->dma_tx_param);
+ if (!pl022->dma_tx_channel) {
+ dev_err(&pl022->adev->dev, "no TX DMA channel!\n");
+ goto err_no_txchan;
+ }
+
+ pl022->dummypage = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!pl022->dummypage) {
+ dev_err(&pl022->adev->dev, "no DMA dummypage!\n");
+ goto err_no_dummypage;
+ }
+
+ dev_info(&pl022->adev->dev, "setup for DMA on RX %s, TX %s\n",
+ dma_chan_name(pl022->dma_rx_channel),
+ dma_chan_name(pl022->dma_tx_channel));
+
+ return 0;
+
+err_no_dummypage:
+ dma_release_channel(pl022->dma_tx_channel);
+err_no_txchan:
+ dma_release_channel(pl022->dma_rx_channel);
+ pl022->dma_rx_channel = NULL;
+err_no_rxchan:
+ return -ENODEV;
+}
+
+static void terminate_dma(struct pl022 *pl022)
+{
+ struct dma_chan *rxchan = pl022->dma_rx_channel;
+ struct dma_chan *txchan = pl022->dma_tx_channel;
+
+ rxchan->device->device_control(rxchan, DMA_TERMINATE_ALL);
+ txchan->device->device_control(txchan, DMA_TERMINATE_ALL);
+ unmap_free_dma_scatter(pl022);
+}
+
+static void inline pl022_dma_remove(struct pl022 *pl022)
+{
+ if (pl022->busy)
+ terminate_dma(pl022);
+ if (pl022->dma_tx_channel)
+ dma_release_channel(pl022->dma_tx_channel);
+ if (pl022->dma_rx_channel)
+ dma_release_channel(pl022->dma_rx_channel);
+ kfree(pl022->dummypage);
+}
+
+#else
+static inline int configure_dma(struct pl022 *pl022)
+{
+ return -ENODEV;
+}
+
+static inline int pl022_dma_probe(struct pl022 *pl022)
+{
+ return 0;
+}
+
+static inline void pl022_dma_remove(struct pl022 *pl022)
+{
+}
+#endif
+
/**
* pl022_interrupt_handler - Interrupt handler for SSP controller
*
@@ -724,20 +1096,34 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id)
return IRQ_HANDLED;
}
+ /*
+ * In DMA mode, this interrupt handler is only
+ * used for handling error conditions.
+ */
+ if (unlikely(pl022->cur_chip->enable_dma)) {
+ dev_err(&pl022->adev->dev,
+ "stray interrupt in DMA mode (0x%08x)", irq_status);
+ writew(CLEAR_ALL_INTERRUPTS, SSP_ICR(pl022->virtbase));
+ return IRQ_HANDLED;
+ }
+
/* Read the Interrupt Status Register */
irq_status = readw(SSP_MIS(pl022->virtbase));
if (unlikely(!irq_status))
return IRQ_NONE;
- /* This handles the error code interrupts */
+ /*
+ * This handles the FIFO interrupts, the timeout
+ * interrupts are flatly ignored, they cannot be
+ * trusted.
+ */
if (unlikely(irq_status & SSP_MIS_MASK_RORMIS)) {
/*
* Overrun interrupt - bail out since our Data has been
* corrupted
*/
- dev_err(&pl022->adev->dev,
- "FIFO overrun\n");
+ dev_err(&pl022->adev->dev, "FIFO overrun\n");
if (readw(SSP_SR(pl022->virtbase)) & SSP_SR_MASK_RFF)
dev_err(&pl022->adev->dev,
"RXFIFO is full\n");
@@ -832,8 +1218,8 @@ static int set_up_next_transfer(struct pl022 *pl022,
}
/**
- * pump_transfers - Tasklet function which schedules next interrupt transfer
- * when running in interrupt transfer mode.
+ * pump_transfers - Tasklet function which schedules next transfer
+ * when running in interrupt or DMA transfer mode.
* @data: SSP driver private data structure
*
*/
@@ -890,65 +1276,23 @@ static void pump_transfers(unsigned long data)
}
/* Flush the FIFOs and let's go! */
flush(pl022);
- writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
-}
-
-/**
- * NOT IMPLEMENTED
- * configure_dma - It configures the DMA pipes for DMA transfers
- * @data: SSP driver's private data structure
- *
- */
-static int configure_dma(void *data)
-{
- struct pl022 *pl022 = data;
- dev_dbg(&pl022->adev->dev, "configure DMA\n");
- return -ENOTSUPP;
-}
-
-/**
- * do_dma_transfer - It handles transfers of the current message
- * if it is DMA xfer.
- * NOT FULLY IMPLEMENTED
- * @data: SSP driver's private data structure
- */
-static void do_dma_transfer(void *data)
-{
- struct pl022 *pl022 = data;
-
- if (configure_dma(data)) {
- dev_dbg(&pl022->adev->dev, "configuration of DMA Failed!\n");
- goto err_config_dma;
- }
-
- /* TODO: Implememt DMA setup of pipes here */
- /* Enable target chip, set up transfer */
- pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
- if (set_up_next_transfer(pl022, pl022->cur_transfer)) {
- /* Error path */
- pl022->cur_msg->state = STATE_ERROR;
- pl022->cur_msg->status = -EIO;
- giveback(pl022);
+ if (pl022->cur_chip->enable_dma) {
+ if (configure_dma(pl022)) {
+ dev_err(&pl022->adev->dev,
+ "configuration of DMA failed, fall back to interrupt mode\n");
+ goto err_config_dma;
+ }
return;
}
- /* Enable SSP */
- writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
- SSP_CR1(pl022->virtbase));
-
- /* TODO: Enable the DMA transfer here */
- return;
- err_config_dma:
- pl022->cur_msg->state = STATE_ERROR;
- pl022->cur_msg->status = -EIO;
- giveback(pl022);
- return;
+err_config_dma:
+ writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
}
-static void do_interrupt_transfer(void *data)
+static void do_interrupt_dma_transfer(struct pl022 *pl022)
{
- struct pl022 *pl022 = data;
+ u32 irqflags = ENABLE_ALL_INTERRUPTS;
/* Enable target chip */
pl022->cur_chip->cs_control(SSP_CHIP_SELECT);
@@ -959,15 +1303,26 @@ static void do_interrupt_transfer(void *data)
giveback(pl022);
return;
}
+ /* If we're using DMA, set up DMA here */
+ if (pl022->cur_chip->enable_dma) {
+ /* Configure DMA transfer */
+ if (configure_dma(pl022)) {
+ dev_err(&pl022->adev->dev,
+ "configuration of DMA failed, fall back to interrupt mode\n");
+ goto err_config_dma;
+ }
+ /* Disable interrupts in DMA mode, IRQ from DMA controller */
+ irqflags = DISABLE_ALL_INTERRUPTS;
+ }
+err_config_dma:
/* Enable SSP, turn on interrupts */
writew((readw(SSP_CR1(pl022->virtbase)) | SSP_CR1_MASK_SSE),
SSP_CR1(pl022->virtbase));
- writew(ENABLE_ALL_INTERRUPTS, SSP_IMSC(pl022->virtbase));
+ writew(irqflags, SSP_IMSC(pl022->virtbase));
}
-static void do_polling_transfer(void *data)
+static void do_polling_transfer(struct pl022 *pl022)
{
- struct pl022 *pl022 = data;
struct spi_message *message = NULL;
struct spi_transfer *transfer = NULL;
struct spi_transfer *previous = NULL;
@@ -1037,7 +1392,7 @@ static void do_polling_transfer(void *data)
*
* This function checks if there is any spi message in the queue that
* needs processing and delegate control to appropriate function
- * do_polling_transfer()/do_interrupt_transfer()/do_dma_transfer()
+ * do_polling_transfer()/do_interrupt_dma_transfer()
* based on the kind of the transfer
*
*/
@@ -1085,10 +1440,8 @@ static void pump_messages(struct work_struct *work)
if (pl022->cur_chip->xfer_type == POLLING_TRANSFER)
do_polling_transfer(pl022);
- else if (pl022->cur_chip->xfer_type == INTERRUPT_TRANSFER)
- do_interrupt_transfer(pl022);
else
- do_dma_transfer(pl022);
+ do_interrupt_dma_transfer(pl022);
}
@@ -1393,23 +1746,6 @@ static int calculate_effective_freq(struct pl022 *pl022,
}
/**
- * NOT IMPLEMENTED
- * process_dma_info - Processes the DMA info provided by client drivers
- * @chip_info: chip info provided by client device
- * @chip: Runtime state maintained by the SSP controller for each spi device
- *
- * This function processes and stores DMA config provided by client driver
- * into the runtime state maintained by the SSP controller driver
- */
-static int process_dma_info(struct pl022_config_chip *chip_info,
- struct chip_data *chip)
-{
- dev_err(chip_info->dev,
- "cannot process DMA info, DMA not implemented!\n");
- return -ENOTSUPP;
-}
-
-/**
* pl022_setup - setup function registered to SPI master framework
* @spi: spi device which is requesting setup
*
@@ -1563,7 +1899,6 @@ static int pl022_setup(struct spi_device *spi)
&& ((pl022->master_info)->enable_dma)) {
chip->enable_dma = 1;
dev_dbg(&spi->dev, "DMA mode set in controller state\n");
- status = process_dma_info(chip_info, chip);
if (status < 0)
goto err_config_params;
SSP_WRITE_BITS(chip->dmacr, SSP_DMA_ENABLED,
@@ -1623,7 +1958,7 @@ static void pl022_cleanup(struct spi_device *spi)
}
-static int __init
+static int __devinit
pl022_probe(struct amba_device *adev, struct amba_id *id)
{
struct device *dev = &adev->dev;
@@ -1670,6 +2005,7 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
if (status)
goto err_no_ioregion;
+ pl022->phybase = adev->res.start;
pl022->virtbase = ioremap(adev->res.start, resource_size(&adev->res));
if (pl022->virtbase == NULL) {
status = -ENOMEM;
@@ -1698,6 +2034,12 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
dev_err(&adev->dev, "probe - cannot get IRQ (%d)\n", status);
goto err_no_irq;
}
+
+ /* Get DMA channels */
+ status = pl022_dma_probe(pl022);
+ if (status != 0)
+ goto err_no_dma;
+
/* Initialize and start queue */
status = init_queue(pl022);
if (status != 0) {
@@ -1724,6 +2066,8 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
err_start_queue:
err_init_queue:
destroy_queue(pl022);
+ pl022_dma_remove(pl022);
+ err_no_dma:
free_irq(adev->irq[0], pl022);
err_no_irq:
clk_put(pl022->clk);
@@ -1738,7 +2082,7 @@ pl022_probe(struct amba_device *adev, struct amba_id *id)
return status;
}
-static int __exit
+static int __devexit
pl022_remove(struct amba_device *adev)
{
struct pl022 *pl022 = amba_get_drvdata(adev);
@@ -1754,6 +2098,7 @@ pl022_remove(struct amba_device *adev)
return status;
}
load_ssp_default_config(pl022);
+ pl022_dma_remove(pl022);
free_irq(adev->irq[0], pl022);
clk_disable(pl022->clk);
clk_put(pl022->clk);
@@ -1846,7 +2191,7 @@ static struct amba_driver pl022_driver = {
},
.id_table = pl022_ids,
.probe = pl022_probe,
- .remove = __exit_p(pl022_remove),
+ .remove = __devexit_p(pl022_remove),
.suspend = pl022_suspend,
.resume = pl022_resume,
};
@@ -201,6 +201,7 @@ enum ssp_chip_select {
};
+struct dma_chan;
/**
* struct pl022_ssp_master - device.platform_data for SPI controller devices.
* @num_chipselect: chipselects are used to distinguish individual
@@ -208,11 +209,16 @@ enum ssp_chip_select {
* each slave has a chipselect signal, but it's common that not
* every chipselect is connected to a slave.
* @enable_dma: if true enables DMA driven transfers.
+ * @dma_rx_param: parameter to locate an RX DMA channel.
+ * @dma_tx_param: parameter to locate a TX DMA channel.
*/
struct pl022_ssp_controller {
u16 bus_id;
u8 num_chipselect;
u8 enable_dma:1;
+ bool (*dma_filter)(struct dma_chan *chan, void *filter_param);
+ void *dma_rx_param;
+ void *dma_tx_param;
};
/**