From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753126Ab0DQFNJ (ORCPT ); Sat, 17 Apr 2010 01:13:09 -0400 Received: from mail.df.lth.se ([194.47.250.12]:52960 "EHLO df.lth.se" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752822Ab0DQFNE (ORCPT ); Sat, 17 Apr 2010 01:13:04 -0400 From: Linus Walleij To: Dan Williams Cc: STEricsson_nomadik_linux@list.st.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linus Walleij Subject: [PATCH 3/3] DMAENGINE: add PrimeCell generic DMA to PL022 v6 Date: Sat, 17 Apr 2010 07:12:45 +0200 Message-Id: <1271481165-9848-1-git-send-email-linus.walleij@stericsson.com> X-Mailer: git-send-email 1.6.2.rc1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This extends the PL022 SSP/SPI driver with generic DMA engine support using the PrimeCell DMA engine interface. Also fix up the test code for the U300 platform. Acked-by: Grant Likely Signed-off-by: Linus Walleij --- Changes from v5: - Rebased on async_tx tree instead --- arch/arm/mach-u300/dummyspichip.c | 1 + drivers/spi/amba-pl022.c | 518 +++++++++++++++++++++++++++++++------ include/linux/amba/pl022.h | 6 + 3 files changed, 439 insertions(+), 86 deletions(-) diff --git a/arch/arm/mach-u300/dummyspichip.c b/arch/arm/mach-u300/dummyspichip.c index 962f9de..6d80468 100644 --- a/arch/arm/mach-u300/dummyspichip.c +++ b/arch/arm/mach-u300/dummyspichip.c @@ -267,6 +267,7 @@ 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), diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c index 9aeb681..c191336 100644 --- a/drivers/spi/amba-pl022.c +++ b/drivers/spi/amba-pl022.c @@ -27,7 +27,6 @@ /* * TODO: * - add timeout on polled transfers - * - add generic DMA framework support */ #include @@ -44,6 +43,11 @@ #include #include #include +#include +#include +#include +#include +#include /* * This macro is used to define some register default values. @@ -364,6 +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 }; /** @@ -698,6 +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 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 * @@ -723,20 +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"); @@ -831,8 +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 * */ @@ -889,65 +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); @@ -958,15 +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; @@ -1036,7 +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 * */ @@ -1084,10 +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); } @@ -1392,23 +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 * @@ -1562,7 +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, @@ -1622,7 +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; @@ -1669,6 +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; @@ -1697,6 +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) { @@ -1723,6 +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); @@ -1737,7 +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); @@ -1753,6 +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); @@ -1845,7 +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, }; diff --git a/include/linux/amba/pl022.h b/include/linux/amba/pl022.h index e4836c6..95f8d17 100644 --- a/include/linux/amba/pl022.h +++ b/include/linux/amba/pl022.h @@ -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; }; /** -- 1.7.0.1