Re: [PATCH 09/11] ARM: add PrimeCell generic DMA to PL022 v5

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On Wed, Apr 7, 2010 at 5:14 PM, Linus Walleij
<linus.walleij@xxxxxxxxxxxxxx> wrote:
> This extends the PL022 UART driver with generic DMA engine support
> using the PrimeCell DMA engine interface. Also fix up the test
> code for the U300 platform.
>
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>

I have not reviewed, compiled, or tested this.  I've only skimmed over
it.  Simply for the purpose of merging the spi portion, you can add my
"Acked-by: Grant Likely <grant.likely@xxxxxxxxxxxx>" line, but collect
other acks from people who will actually review it.

g.

> ---
>  arch/arm/mach-u300/dummyspichip.c |    1 +
>  drivers/spi/amba-pl022.c          |  517 +++++++++++++++++++++++++++++++------
>  include/linux/amba/pl022.h        |    6 +
>  3 files changed, 438 insertions(+), 86 deletions(-)
>
> diff --git a/arch/arm/mach-u300/dummyspichip.c b/arch/arm/mach-u300/dummyspichip.c
> index 5f55012..5672189 100644
> --- a/arch/arm/mach-u300/dummyspichip.c
> +++ b/arch/arm/mach-u300/dummyspichip.c
> @@ -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),
> diff --git a/drivers/spi/amba-pl022.c b/drivers/spi/amba-pl022.c
> index e9aeee1..09a701c 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 <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,
>  };
> 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;
>  };
>
>  /**
> --
> 1.6.3.3
>
>



-- 
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.
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