Messages in this thread | | | From | "Yang, Wenyou" <> | Subject | RE: [v4 PATCH 06/12] spi/atmel_spi: add dmaengine support | Date | Thu, 24 Jan 2013 00:44:15 +0000 |
| |
Thanks a lot for so much comments
> -----Original Message----- > From: Richard Genoud [mailto:richard.genoud@gmail.com] > Sent: 2013年1月24日 0:25 > To: Yang, Wenyou > Cc: linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org; Ferre, > Nicolas; plagnioj@jcrosoft.com; Lin, JM; grant.likely@secretlab.ca; > spi-devel-general@lists.sourceforge.net > Subject: Re: [v4 PATCH 06/12] spi/atmel_spi: add dmaengine support > > 2013/1/14 Wenyou Yang <wenyou.yang@atmel.com>: > > From: Nicolas Ferre <nicolas.ferre@atmel.com> > > > > Add dmaengine support. > > > > For different SoC, the "has_dma_support" is used to select > > the transfer mode: dmaengine or PDC. > > > > For the dmaengine transfer mode, if it fails to config dmaengine, > > or if the message len less than 16 bytes, it will use the PIO transfer mode. > > > > Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> > > [wenyou.yang@atmel.com: using "has_dma_support" to select DMA as the > spi xfer mode] > > [wenyou.yang@atmel.com: add support NPCS1,2,3 chip select other than > NPCS0] > > [wenyou.yang@atmel.com: fix DMA: OOPS if buffer > 4096 bytes] > > Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com> > > Cc: grant.likely@secretlab.ca > > Cc: spi-devel-general@lists.sourceforge.net > > Cc: richard.genoud@gmail.com > > --- > > This patch is based on the original patch from Nicolas > > [PATCH] spi/atmel_spi: add dmaengine support > > and merge the patches from Richard Genoud <richard.genoud@gmail.com> > > [PATCH] spi-atmel: update with dmaengine interface > > [PATCH] spi-atmel: fix __init/__devinit sections mismatch > > and Wenyou Yang add the code to support selecting the spi transfer mode, > > add support NPCS1,2,3 chip select other than NPCS0. > > fix DMA: OOPS if buffer > 4096 bytes. > > > > diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c > > index 43c1f63..0d242dc 100644 > > --- a/drivers/spi/spi-atmel.c > > +++ b/drivers/spi/spi-atmel.c > > @@ -15,11 +15,13 @@ > > #include <linux/platform_device.h> > > #include <linux/delay.h> > > #include <linux/dma-mapping.h> > > +#include <linux/dmaengine.h> > > #include <linux/err.h> > > #include <linux/interrupt.h> > > #include <linux/spi/spi.h> > > #include <linux/slab.h> > > #include <linux/platform_data/atmel.h> > > +#include <linux/platform_data/dma-atmel.h> > > #include <linux/of.h> > > > > #include <asm/io.h> > > @@ -182,6 +184,19 @@ > > #define spi_writel(port,reg,value) \ > > __raw_writel((value), (port)->regs + SPI_##reg) > > > > +/* use PIO for small transfers, avoiding DMA setup/teardown overhead and > > + * cache operations; better heuristics consider wordsize and bitrate. > > + */ > > +#define DMA_MIN_BYTES 16 > > + > > +struct atmel_spi_dma { > > + struct dma_chan *chan_rx; > > + struct dma_chan *chan_tx; > > + struct scatterlist sgrx; > > + struct scatterlist sgtx; > > + struct dma_async_tx_descriptor *data_desc_rx; > > + struct dma_async_tx_descriptor *data_desc_tx; > > +}; > > > > /* > > * The core SPI transfer engine just talks to a register bank to set up > > @@ -192,6 +207,7 @@ struct atmel_spi_pdata { > > u8 version; > > bool has_dma_support; > > bool has_wdrbt; > > + struct at_dma_slave dma_slave; > > }; > > > > struct atmel_spi { > > @@ -207,6 +223,7 @@ struct atmel_spi { > > > > u8 stopping; > > struct list_head queue; > > + struct tasklet_struct tasklet; > > struct spi_transfer *current_transfer; > > unsigned long current_remaining_bytes; > > struct spi_transfer *next_transfer; > > @@ -214,8 +231,15 @@ struct atmel_spi { > > int done_status; > > struct atmel_spi_pdata *pdata; > > > > + bool use_dma; > > + bool use_pdc; > > + > > + /* scratch buffer */ > > void *buffer; > > dma_addr_t buffer_dma; > > + > > + /* dmaengine data */ > > + struct atmel_spi_dma dma; > > }; > > > > /* Controller-specific per-slave state */ > > @@ -328,9 +352,7 @@ static bool atmel_spi_is_v2(struct atmel_spi *as) > > * and (c) will trigger that first erratum in some cases. > > * > > * TODO: Test if the atmel_spi_is_v2() branch below works on > > - * AT91RM9200 if we use some other register than CSR0. However, don't > > - * do this unconditionally since AP7000 has an errata where the BITS > > - * field in CSR0 overrides all other CSRs. > > + * AT91RM9200 if we use some other register than CSR0. > > */ > > > > static void cs_activate(struct atmel_spi *as, struct spi_device *spi) > > @@ -340,18 +362,16 @@ static void cs_activate(struct atmel_spi *as, > struct spi_device *spi) > > u32 mr; > > > > if (atmel_spi_is_v2(as)) { > > - /* > > - * Always use CSR0. This ensures that the clock > > - * switches to the correct idle polarity before we > > - * toggle the CS. > > - */ > > - spi_writel(as, CSR0, asd->csr); > > + spi_writel(as, CSR0 + 4 * spi->chip_select, asd->csr); > > > > if (as->pdata->has_wdrbt) > > - spi_writel(as, MR, SPI_BF(PCS, 0x0e) | > SPI_BIT(MSTR) > > - | SPI_BIT(MODFDIS) | > SPI_BIT(WDRBT)); > > + spi_writel(as, MR, > > + SPI_BF(PCS, ~(0x01 << > spi->chip_select)) > > + | SPI_BIT(MSTR) | > SPI_BIT(MODFDIS) > > + | SPI_BIT(WDRBT)); > > else > > - spi_writel(as, MR, SPI_BF(PCS, 0x0e) > > + spi_writel(as, MR, > > + SPI_BF(PCS, ~(0x01 << > spi->chip_select)) > > | SPI_BIT(MSTR) | > SPI_BIT(MODFDIS)); > > > > mr = spi_readl(as, MR); > > @@ -414,6 +434,12 @@ static void atmel_spi_unlock(struct atmel_spi *as) > > spin_unlock_irqrestore(&as->lock, as->flags); > > } > > > > +static inline bool atmel_spi_use_dma(struct atmel_spi *as, > > + struct spi_transfer *xfer) > > +{ > > + return as->use_dma && xfer->len >= DMA_MIN_BYTES; > > +} > > + > > static inline int atmel_spi_xfer_is_last(struct spi_message *msg, > > struct spi_transfer *xfer) > > { > > @@ -425,6 +451,220 @@ static inline int > atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer) > > return xfer->delay_usecs == 0 && !xfer->cs_change; > > } > > > > +static bool filter(struct dma_chan *chan, void *slave) > > +{ > > + struct at_dma_slave *sl = slave; > > + > > + if (sl->dma_dev == chan->device->dev) { > > + chan->private = sl; > > + return true; > > + } else { > > + return false; > > + } > > +} > > + > > +static int __devinit atmel_spi_configure_dma(struct atmel_spi *as) > > +{ > > + struct at_dma_slave *sdata > > + = (struct at_dma_slave > *)&as->pdata->dma_slave; > > + > > + if (sdata && sdata->dma_dev) { > > + dma_cap_mask_t mask; > > + > > + /* setup DMA addresses */ > > + sdata->rx_reg = (dma_addr_t)as->phybase + SPI_RDR; > > + sdata->tx_reg = (dma_addr_t)as->phybase + SPI_TDR; > > + > > + /* Try to grab two DMA channels */ > > + dma_cap_zero(mask); > > + dma_cap_set(DMA_SLAVE, mask); > > + as->dma.chan_tx = dma_request_channel(mask, filter, > sdata); > > + if (as->dma.chan_tx) > > + as->dma.chan_rx = > > + dma_request_channel(mask, filter, > sdata); > > + } > > + if (!as->dma.chan_rx || !as->dma.chan_tx) { > > + if (as->dma.chan_rx) > > + dma_release_channel(as->dma.chan_rx); > > + if (as->dma.chan_tx) > > + dma_release_channel(as->dma.chan_tx); > > + dev_err(&as->pdev->dev, > > + "DMA channel not available, unable to use > SPI\n"); > > + return -EBUSY; > > + } > > + > > + dev_info(&as->pdev->dev, > > + "Using %s (tx) and %s (rx) for DMA > transfers\n", > > + dma_chan_name(as->dma.chan_tx), > > + dma_chan_name(as->dma.chan_rx)); > > + > > + return 0; > > +} > > + > > +static void atmel_spi_stop_dma(struct atmel_spi *as) > > +{ > > + if (as->dma.chan_rx) > > + > as->dma.chan_rx->device->device_control(as->dma.chan_rx, > > + > DMA_TERMINATE_ALL, 0); > > + if (as->dma.chan_tx) > > + > as->dma.chan_tx->device->device_control(as->dma.chan_tx, > > + > DMA_TERMINATE_ALL, 0); > > +} > > + > > +static void atmel_spi_release_dma(struct atmel_spi *as) > > +{ > > + if (as->dma.chan_rx) > > + dma_release_channel(as->dma.chan_rx); > > + if (as->dma.chan_tx) > > + dma_release_channel(as->dma.chan_tx); > > +} > > + > > +/* This function is called by the DMA driver from tasklet context */ > > +static void dma_callback(void *data) > > +{ > > + struct spi_master *master = data; > > + struct atmel_spi *as = spi_master_get_devdata(master); > > + > > + /* trigger SPI tasklet */ > > + tasklet_schedule(&as->tasklet); > > +} > > + > > +/* > > + * Next transfer using PIO. > > + * lock is held, spi tasklet is blocked > > + */ > > +static void atmel_spi_next_xfer_pio(struct spi_master *master, > > + struct spi_transfer *xfer) > > +{ > > + struct atmel_spi *as = spi_master_get_devdata(master); > > + > > + dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_pio\n"); > > + > > + as->current_remaining_bytes = xfer->len; > > + > > + /* Make sure data is not remaining in RDR */ > > + spi_readl(as, RDR); > > + while (spi_readl(as, SR) & SPI_BIT(RDRF)) { > > + spi_readl(as, RDR); > > + cpu_relax(); > > + } > > + > > + if (xfer->tx_buf) > > + spi_writel(as, TDR, *(u8 *)(xfer->tx_buf)); > > + else > > + spi_writel(as, TDR, 0); > > + > > + dev_dbg(master->dev.parent, > > + " start pio xfer %p: len %u tx %p rx %p\n", > > + xfer, xfer->len, xfer->tx_buf, xfer->rx_buf); > > + > > + /* Enable relevant interrupts */ > > + spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES)); > > +} > > + > > +/* > > + * Submit next transfer for DMA. > > + * lock is held, spi tasklet is blocked > > + */ > > +static int atmel_spi_next_xfer_dma_submit(struct spi_master *master, > > + struct spi_transfer *xfer, > > + u32 *plen) > > +{ > > + struct atmel_spi *as = spi_master_get_devdata(master); > > + struct dma_chan *rxchan = as->dma.chan_rx; > > + struct dma_chan *txchan = as->dma.chan_tx; > > + struct dma_async_tx_descriptor *rxdesc; > > + struct dma_async_tx_descriptor *txdesc; > > + dma_cookie_t cookie; > > + u32 len = *plen; > > + > > + dev_vdbg(master->dev.parent, > "atmel_spi_next_xfer_dma_submit\n"); > > + > > + /* Check that the channels are available */ > > + if (!rxchan || !txchan) > > + return -ENODEV; > > + > > + /* release lock for DMA operations */ > > + atmel_spi_unlock(as); > > + > > + /* prepare the RX dma transfer */ > > + sg_init_table(&as->dma.sgrx, 1); > > + if (xfer->rx_buf) > > + as->dma.sgrx.dma_address = xfer->rx_dma + xfer->len - > *plen; > > + else { > > + as->dma.sgrx.dma_address = as->buffer_dma; > > + if (len > BUFFER_SIZE) > > + len = BUFFER_SIZE; > > + } > You should use brackets before the "else" also. > cf Documentation/CodingStyle line 169 : > > This does not apply if only one branch of a conditional statement is a single > statement; in the latter case use braces in both branches: > > if (condition) { > do_this(); > do_that(); > } else { > otherwise(); > } > > > > + > > + /* prepare the TX dma transfer */ > > + sg_init_table(&as->dma.sgtx, 1); > > + if (xfer->tx_buf) { > > + as->dma.sgtx.dma_address = xfer->tx_dma + xfer->len - > *plen; > > + } else { > > + as->dma.sgtx.dma_address = as->buffer_dma; > > + if (len > BUFFER_SIZE) > > + len = BUFFER_SIZE; > > + memset(as->buffer, 0, len); > > + } > > + > > + sg_dma_len(&as->dma.sgtx) = len; > > + sg_dma_len(&as->dma.sgrx) = len; > > + > > + *plen = len; > > + > > + /* Send both scatterlists */ > > + rxdesc = rxchan->device->device_prep_slave_sg(rxchan, > > + &as->dma.sgrx, > > + 1, > > + DMA_FROM_DEVICE, > > + DMA_PREP_INTERRUPT | > DMA_CTRL_ACK, > > + NULL); > > + if (!rxdesc) > > + goto err_dma; > > + > > + txdesc = txchan->device->device_prep_slave_sg(txchan, > > + &as->dma.sgtx, > > + 1, > > + DMA_TO_DEVICE, > > + DMA_PREP_INTERRUPT | > DMA_CTRL_ACK, > > + NULL); > > + if (!txdesc) > > + goto err_dma; > > + > > + dev_dbg(master->dev.parent, > > + " start dma xfer %p: len %u tx %p/%08x rx %p/%08x\n", > > + xfer, xfer->len, xfer->tx_buf, xfer->tx_dma, > > + xfer->rx_buf, xfer->rx_dma); > > + > > + /* Enable relevant interrupts */ > > + spi_writel(as, IER, SPI_BIT(OVRES)); > > + > > + /* Put the callback on the RX transfer only, that should finish last */ > > + rxdesc->callback = dma_callback; > > + rxdesc->callback_param = master; > > + > > + /* Submit and fire RX and TX with TX last so we're ready to read! */ > > + cookie = rxdesc->tx_submit(rxdesc); > > + if (dma_submit_error(cookie)) > > + goto err_dma; > > + cookie = txdesc->tx_submit(txdesc); > > + if (dma_submit_error(cookie)) > > + goto err_dma; > > + rxchan->device->device_issue_pending(rxchan); > > + txchan->device->device_issue_pending(txchan); > > + > > + /* take back lock */ > > + atmel_spi_lock(as); > > + return 0; > > + > > +err_dma: > > + spi_writel(as, IDR, SPI_BIT(OVRES)); > > + atmel_spi_stop_dma(as); > > + atmel_spi_lock(as); > > + return -ENOMEM; > > +} > > + > > static void atmel_spi_next_xfer_data(struct spi_master *master, > > struct spi_transfer *xfer, > > dma_addr_t *tx_dma, > > @@ -457,10 +697,10 @@ static void atmel_spi_next_xfer_data(struct > spi_master *master, > > } > > > > /* > > - * Submit next transfer for DMA. > > + * Submit next transfer for PDC. > > * lock is held, spi irq is blocked > > */ > > -static void atmel_spi_next_xfer(struct spi_master *master, > > +static void atmel_spi_next_xfer_pdc(struct spi_master *master, > > struct spi_message *msg) > > { > > struct atmel_spi *as = spi_master_get_devdata(master); > > @@ -557,6 +797,49 @@ static void atmel_spi_next_xfer(struct spi_master > *master, > > spi_writel(as, PTCR, SPI_BIT(TXTEN) | SPI_BIT(RXTEN)); > > } > > > > +/* > > + * Choose way to submit next transfer and start it. > > + * lock is held, spi tasklet is blocked > > + */ > > +static void atmel_spi_next_xfer_dma(struct spi_master *master, > > + struct spi_message *msg) > > +{ > > + struct atmel_spi *as = spi_master_get_devdata(master); > > + struct spi_transfer *xfer; > > + u32 remaining, len; > > + > > + dev_vdbg(&msg->spi->dev, "atmel_spi_next_xfer\n"); > > + > > + remaining = as->current_remaining_bytes; > > + if (remaining) { > > + xfer = as->current_transfer; > > + len = remaining; > > + } else { > > + if (!as->current_transfer) > > + xfer = list_entry(msg->transfers.next, > > + struct spi_transfer, transfer_list); > > + else > > + xfer = list_entry( > > + > as->current_transfer->transfer_list.next, > > + struct spi_transfer, > transfer_list); > > + > > + as->current_transfer = xfer; > > + len = xfer->len; > > + } > > + > > + if (atmel_spi_use_dma(as, xfer)) { > > + u32 total = len; > > + if (!atmel_spi_next_xfer_dma_submit(master, xfer, &len)) > { > > + as->current_remaining_bytes = total - len; > > + return; > > + } else > > + dev_err(&msg->spi->dev, "unable to use DMA, > fallback to PIO\n"); > same here. > > + } > > + > > + /* use PIO if error appened using DMA */ > > + atmel_spi_next_xfer_pio(master, xfer); > > +} > > + > > static void atmel_spi_next_message(struct spi_master *master) > > { > > struct atmel_spi *as = spi_master_get_devdata(master); > > @@ -581,7 +864,10 @@ static void atmel_spi_next_message(struct > spi_master *master) > > } else > > cs_activate(as, spi); > > > > - atmel_spi_next_xfer(master, msg); > > + if (as->use_pdc) > > + atmel_spi_next_xfer_pdc(master, msg); > > + else > > + atmel_spi_next_xfer_dma(master, msg); > > } > > > > /* > > @@ -634,6 +920,11 @@ static void atmel_spi_dma_unmap_xfer(struct > spi_master *master, > > xfer->len, DMA_FROM_DEVICE); > > } > > > > +static void atmel_spi_disable_pdc_transfer(struct atmel_spi *as) > > +{ > > + spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); > > +} > > + > > static void > > atmel_spi_msg_done(struct spi_master *master, struct atmel_spi *as, > > struct spi_message *msg, int stay) > > @@ -659,19 +950,175 @@ atmel_spi_msg_done(struct spi_master *master, > struct atmel_spi *as, > > as->done_status = 0; > > > > /* continue if needed */ > > - if (list_empty(&as->queue) || as->stopping) > > - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); > > - else > > + if (list_empty(&as->queue) || as->stopping) { > > + if (as->use_pdc) > > + atmel_spi_disable_pdc_transfer(as); > > + } else > > atmel_spi_next_message(master); > same. > > } > > > > -static irqreturn_t > > -atmel_spi_interrupt(int irq, void *dev_id) > > +/* Called from IRQ > > + * lock is held > > + * > > + * Must update "current_remaining_bytes" to keep track of data > > + * to transfer. > > + */ > > +static void > > +atmel_spi_pump_pio_data(struct atmel_spi *as, struct spi_transfer *xfer) > > { > > - struct spi_master *master = dev_id; > > + u8 *txp; > > + u8 *rxp; > > + unsigned long xfer_pos = xfer->len - > as->current_remaining_bytes; > > + > > + if (xfer->rx_buf) { > > + rxp = ((u8 *)xfer->rx_buf) + xfer_pos; > > + *rxp = spi_readl(as, RDR); > > + } else { > > + spi_readl(as, RDR); > > + } > > + > > + as->current_remaining_bytes--; > > + > > + if (as->current_remaining_bytes) { > > + if (xfer->tx_buf) { > > + txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1; > > + spi_writel(as, TDR, *txp); > > + } else { > > + spi_writel(as, TDR, 0); > > + } > > + } > > +} > > + > > +/* Tasklet > > + * Called from DMA callback + pio transfer and overrun IRQ. > > + */ > > +static void atmel_spi_tasklet_func(unsigned long data) > > +{ > > + struct spi_master *master = (struct spi_master *)data; > > struct atmel_spi *as = spi_master_get_devdata(master); > > struct spi_message *msg; > > struct spi_transfer *xfer; > > + > > + dev_vdbg(master->dev.parent, "atmel_spi_tasklet_func\n"); > > + > > + atmel_spi_lock(as); > > + > > + xfer = as->current_transfer; > > + > > + if (xfer == NULL) > > + /* already been there */ > > + goto tasklet_out; > > + > > + msg = list_entry(as->queue.next, struct spi_message, queue); > > + > > + if (as->current_remaining_bytes == 0) { > > + if (as->done_status < 0) { > > + /* error happened (overrun) */ > > + if (atmel_spi_use_dma(as, xfer)) > > + atmel_spi_stop_dma(as); > > + } else > > + /* only update length if no error */ > > + msg->actual_length += xfer->len; > same > > + > > + if (atmel_spi_use_dma(as, xfer)) > > + if (!msg->is_dma_mapped) > > + atmel_spi_dma_unmap_xfer(master, > xfer); > > + > > + if (xfer->delay_usecs) > > + udelay(xfer->delay_usecs); > > + > > + if (atmel_spi_xfer_is_last(msg, xfer) || as->done_status < > 0) > > + /* report completed (or erroneous) message */ > > + atmel_spi_msg_done(master, as, msg, > xfer->cs_change); > > + else { > same > > + if (xfer->cs_change) { > > + cs_deactivate(as, msg->spi); > > + udelay(1); > > + cs_activate(as, msg->spi); > > + } > > + > > + /* > > + * Not done yet. Submit the next transfer. > > + * > > + * FIXME handle protocol options for xfer > > + */ > > + atmel_spi_next_xfer_dma(master, msg); > > + } > > + } else > same > > + /* > > + * Keep going, we still have data to send in > > + * the current transfer. > > + */ > > + atmel_spi_next_xfer_dma(master, msg); > > + > > +tasklet_out: > > + atmel_spi_unlock(as); > > +} > > + > > +static int atmel_spi_interrupt_dma(struct atmel_spi *as, > > + struct spi_master *master) > > +{ > > + u32 status, pending, imr; > > + struct spi_transfer *xfer; > > + int ret = IRQ_NONE; > > + > > + imr = spi_readl(as, IMR); > > + status = spi_readl(as, SR); > > + pending = status & imr; > > + > > + if (pending & SPI_BIT(OVRES)) { > > + ret = IRQ_HANDLED; > > + spi_writel(as, IDR, SPI_BIT(OVRES)); > > + dev_warn(master->dev.parent, "overrun\n"); > > + > > + /* > > + * When we get an overrun, we disregard the current > > + * transfer. Data will not be copied back from any > > + * bounce buffer and msg->actual_len will not be > > + * updated with the last xfer. > > + * > > + * We will also not process any remaning transfers in > > + * the message. > > + * > > + * All actions are done in tasklet with done_status > indication > > + */ > > + as->done_status = -EIO; > > + smp_wmb(); > > + > > + /* Clear any overrun happening while cleaning up */ > > + spi_readl(as, SR); > > + > > + tasklet_schedule(&as->tasklet); > > + > > + } else if (pending & SPI_BIT(RDRF)) { > > + atmel_spi_lock(as); > > + > > + if (as->current_remaining_bytes) { > > + ret = IRQ_HANDLED; > > + xfer = as->current_transfer; > > + atmel_spi_pump_pio_data(as, xfer); > > + if (!as->current_remaining_bytes) { > > + /* no more data to xfer, kick tasklet */ > > + spi_writel(as, IDR, pending); > > + tasklet_schedule(&as->tasklet); > > + } > > + } > > + > > + atmel_spi_unlock(as); > > + } else { > > + WARN_ONCE(pending, "IRQ not handled, pending > = %x\n", pending); > > + ret = IRQ_HANDLED; > > + spi_writel(as, IDR, pending); > > + } > > + > > + return ret; > > +} > > + > > +static int atmel_spi_interrupt_pdc(struct atmel_spi *as, > > + struct spi_master *master) > > +{ > > + struct spi_message *msg; > > + struct spi_transfer *xfer; > > u32 status, pending, imr; > > int ret = IRQ_NONE; > > > > @@ -767,14 +1214,14 @@ atmel_spi_interrupt(int irq, void *dev_id) > > * > > * FIXME handle protocol options for > xfer > > */ > > - atmel_spi_next_xfer(master, msg); > > + atmel_spi_next_xfer_pdc(master, > msg); > > } > > } else { > > /* > > * Keep going, we still have data to send in > > * the current transfer. > > */ > > - atmel_spi_next_xfer(master, msg); > > + atmel_spi_next_xfer_pdc(master, msg); > > } > > } > > > > @@ -783,6 +1230,27 @@ atmel_spi_interrupt(int irq, void *dev_id) > > return ret; > > } > > > > +/* Interrupt > > + * > > + * No need for locking in this Interrupt handler: done_status is the > > + * only information modified. What we need is the update of this field > > + * before tasklet runs. This is ensured by using barrier. > > + */ > > +static irqreturn_t > > +atmel_spi_interrupt(int irq, void *dev_id) > > +{ > > + struct spi_master *master = dev_id; > > + struct atmel_spi *as = spi_master_get_devdata(master); > > + int ret; > > + > > + if (as->use_pdc) > > + ret = atmel_spi_interrupt_pdc(as, master); > > + else > > + ret = atmel_spi_interrupt_dma(as, master); > > + > > + return ret; > > +} > > + > > static int atmel_spi_setup(struct spi_device *spi) > > { > > struct atmel_spi *as; > > @@ -945,13 +1413,10 @@ static int atmel_spi_transfer(struct spi_device > *spi, struct spi_message *msg) > > > > /* > > * DMA map early, for performance (empties dcache > ASAP) and > > - * better fault reporting. This is a DMA-only driver. > > - * > > - * NOTE that if dma_unmap_single() ever starts to do > work on > > - * platforms supported by this driver, we would need to > clean > > - * up mappings for previously-mapped transfers. > > + * better fault reporting. > > */ > > - if (!msg->is_dma_mapped) { > > + if ((!msg->is_dma_mapped) && (atmel_spi_use_dma(as, > xfer) > > + || as->use_pdc)) { > > if (atmel_spi_dma_map_xfer(as, xfer) < 0) > > return -ENOMEM; > > } > > @@ -1068,6 +1533,8 @@ static int atmel_spi_probe(struct platform_device > *pdev) > > > > spin_lock_init(&as->lock); > > INIT_LIST_HEAD(&as->queue); > > + tasklet_init(&as->tasklet, atmel_spi_tasklet_func, > > + (unsigned long)master); > > as->pdev = pdev; > > as->regs = ioremap(regs->start, resource_size(regs)); > > if (!as->regs) > > @@ -1096,7 +1563,15 @@ static int atmel_spi_probe(struct > platform_device *pdev) > > else > > spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); > > > > - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); > > + as->use_dma = false; > > + as->use_pdc = false; > > + > > + if (as->pdata->has_dma_support) { > > + if (atmel_spi_configure_dma(as) == 0) > > + as->use_dma = true; > > + } else > > + as->use_pdc = true; > same. > > Maybe you should add a little dev_info in case both use_dma and > use_pcd are null: > if (!as->use_dma && !as->use_pdc) > dev_info(&pdev->dev, "Atmel SPI Controller: Using PIO only for transferts"); > > I tested it on sam9g35. > It's working *almost* all right. > I've got a problem with the ioctl SPI_IOC_MESSAGE(). > (cf Documentation/spi/spidev_fdx.c) > I'm reading on spidev something like that : > struct spi_ioc_transfer xfer[3]; > memset(xfer, 0, sizeof(xfer)); > xfer[0].tx_buf = (unsigned long)&tx_header; > xer[0].rx_buf = (unsigned long)&rx_header; > xfer[0].len = 2; > xfer[1].rx_buf = (unsigned long)rx_buf; > xfer[1].len = 124; > xfer[2].tx_buf = (unsigned long)&tx_footer; > xfer[2].rx_buf = (unsigned long)&rx_footer; > xfer[2].len = 2; > > nb = ioctl(spi_data->fd, SPI_IOC_MESSAGE(3), xfer); > > If I force DMA all the time with > #define DMA_MIN_BYTES 1 > I haven't got any problem, all works ok. > If I for PIO all the time with > #define DMA_MIN_BYTES 1000 > I'ts woking also without any problem. > > BUT > When the DMA_MIN_BYTES are at 16 (so, xfer[0] is transfered by PIO, > xfer[1] by DMA and xfer[2] by PIO), I've got a lot of errors in my > rx_buffer. > ie, I'm not receiving what I should. > > Did you experience anything like that ? No, I didn't try it. I will do next week. > > Regards, > Richard
Best Regards, Wenyou Yang
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