From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Wed, 26 Sep 2012 09:05:11 +0200 Subject: [PATCH 2/6] spi: atmel: add dmaengine and dt support In-Reply-To: <1348642261-27554-3-git-send-email-wenyou.yang@atmel.com> References: <1348642261-27554-1-git-send-email-wenyou.yang@atmel.com> <1348642261-27554-3-git-send-email-wenyou.yang@atmel.com> Message-ID: <20120926070511.GI21730@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello, On Wed, Sep 26, 2012 at 02:50:57PM +0800, Wenyou Yang wrote: > Signed-off-by: Nicolas Ferre > Signed-off-by: Uwe Kleine-K?nig I don't remember ever having touched the spi-atmel driver, so I'm pretty sure I never gave my S-o-b for anything in this patch. Please reread Documentation/SubmittingPatches and double check you understood what Signed-off-by means before resubmitting this patch with all wrong S-o-b's removed. Best regards Uwe > Signed-off-by: Richard Genoud > Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD > Signed-off-by: Wenyou Yang > --- > .../devicetree/bindings/spi/spi_atmel.txt | 29 + > drivers/spi/spi-atmel.c | 739 ++++++++++++++++++-- > 2 files changed, 696 insertions(+), 72 deletions(-) > create mode 100644 Documentation/devicetree/bindings/spi/spi_atmel.txt > > diff --git a/Documentation/devicetree/bindings/spi/spi_atmel.txt b/Documentation/devicetree/bindings/spi/spi_atmel.txt > new file mode 100644 > index 0000000..5a64825 > --- /dev/null > +++ b/Documentation/devicetree/bindings/spi/spi_atmel.txt > @@ -0,0 +1,29 @@ > +Atmel SPI device > + > +Required properties: > +- compatible : should be "atmel,at91rm9200-spi". > +- reg: Address and length of the register set for the device > +- interrupts: Should contain macb interrupt > +- cs-gpio: Should contain the GPIOs used for chipselect. > +- has_dma_support: The chip has dma engine support for spi: 1 - support, 0 - no support > +- has_pdc_support: The chip has pdc support for spi: 1 - support, 0 - no support > +- is_ver2: If is th spi IP version 2, 1 - yes, 0 - no > +- dma: handle to the dma controller that should be used > + > +spi0: spi at f0000000 { > + #address-cells = <1>; > + #size-cells = <0>; > + compatible = "atmel,at91rm9200-spi"; > + reg = <0xf0000000 0x100>; > + interrupts = <13 4>; > + cs-gpios = <&pioA 14 0 > + &pioA 7 0 /* conflicts with TXD2 */ > + &pioA 1 0 /* conflicts with RXD0 */ > + &pioB 3 0 /* conflicts with ERXDV */ > + >; > + has_dma_support = <1>; > + has_pdc_support = <0>; > + is_ver2 = <1>; > + dma = <&dma0 0x10002212>; > + status = "disabled"; > +}; > diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c > index 16d6a83..9930438 100644 > --- a/drivers/spi/spi-atmel.c > +++ b/drivers/spi/spi-atmel.c > @@ -15,15 +15,19 @@ > #include > #include > #include > +#include > #include > #include > #include > #include > +#include > +#include > > #include > #include > #include > #include > +#include > > /* SPI register offsets */ > #define SPI_CR 0x0000 > @@ -179,6 +183,38 @@ > #define spi_writel(port,reg,value) \ > __raw_writel((value), (port)->regs + SPI_##reg) > > +/* > + * Version 2 of the SPI controller has > + * - CR.LASTXFER > + * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) > + * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) > + * - SPI_CSRx.CSAAT > + * - SPI_CSRx.SBCR allows faster clocking > + * > + * We can determine the controller version by reading the VERSION > + * register, but I haven't checked that it exists on all chips, and > + * this is cheaper anyway. > + */ > +struct atmel_spi_data { > + u8 has_dma_support; > + u8 has_pdc_support; > + u8 is_ver2; /* 1-yes, 0-not */ > + struct at_dma_slave dma_slave; > +}; > + > +/* 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 > @@ -187,7 +223,9 @@ > */ > struct atmel_spi { > spinlock_t lock; > + unsigned long flags; > > + resource_size_t phybase; > void __iomem *regs; > int irq; > struct clk *clk; > @@ -196,13 +234,23 @@ 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; > unsigned long next_remaining_bytes; > + int done_status; > + struct atmel_spi_data data; > > + 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 */ > @@ -214,22 +262,7 @@ struct atmel_spi_device { > #define BUFFER_SIZE PAGE_SIZE > #define INVALID_DMA_ADDRESS 0xffffffff > > -/* > - * Version 2 of the SPI controller has > - * - CR.LASTXFER > - * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) > - * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) > - * - SPI_CSRx.CSAAT > - * - SPI_CSRx.SBCR allows faster clocking > - * > - * We can determine the controller version by reading the VERSION > - * register, but I haven't checked that it exists on all chips, and > - * this is cheaper anyway. > - */ > -static bool atmel_spi_is_v2(void) > -{ > - return !cpu_is_at91rm9200(); > -} > +static struct dma_slave_config slave_config; > > /* > * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby > @@ -250,7 +283,7 @@ static bool atmel_spi_is_v2(void) > * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, > * and (c) will trigger that first erratum in some cases. > * > - * TODO: Test if the atmel_spi_is_v2() branch below works on > + * TODO: Test if the as->data.is_ver2 == 0 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. > @@ -262,7 +295,7 @@ static void cs_activate(struct atmel_spi *as, struct spi_device *spi) > unsigned active = spi->mode & SPI_CS_HIGH; > u32 mr; > > - if (atmel_spi_is_v2()) { > + if (as->data.is_ver2 == 1) { > /* > * Always use CSR0. This ensures that the clock > * switches to the correct idle polarity before we > @@ -317,10 +350,29 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) > asd->npcs_pin, active ? " (low)" : "", > mr); > > - if (atmel_spi_is_v2() || spi->chip_select != 0) > + if ((as->data.is_ver2 == 1) || spi->chip_select != 0) > gpio_set_value(asd->npcs_pin, !active); > } > > +static void atmel_spi_lock(struct atmel_spi *as) > +{ > + spin_lock_irqsave(&as->lock, as->flags); > +} > + > +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) > +{ > + if ((as->use_dma) && (xfer->len >= DMA_MIN_BYTES)) > + return true; > + else > + return false; > +} > + > static inline int atmel_spi_xfer_is_last(struct spi_message *msg, > struct spi_transfer *xfer) > { > @@ -332,6 +384,255 @@ static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer) > return xfer->delay_usecs == 0 && !xfer->cs_change; > } > > +/* > + * 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) > + if (xfer->bits_per_word > 8) > + spi_writel(as, TDR, *(u16 *)(xfer->tx_buf)); > + else > + 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 bitpw %d\n", > + xfer, xfer->len, xfer->tx_buf, xfer->rx_buf, > + xfer->bits_per_word); > + > + /* Enable relevant interrupts */ > + spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES)); > +} > + > +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 atmel_spi_set_dma_xfer_width(struct atmel_spi *as, u8 bits_per_word) > +{ > + int err = 0; > + > + if (bits_per_word > 8) { > + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; > + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; > + } else { > + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; > + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; > + } > + > + slave_config.direction = DMA_TO_DEVICE; > + if (dmaengine_slave_config(as->dma.chan_tx, &slave_config)) { > + dev_err(&as->pdev->dev, > + "failed to configure tx dma channel\n"); > + err = -EINVAL; > + } > + > + slave_config.direction = DMA_FROM_DEVICE; > + if (dmaengine_slave_config(as->dma.chan_rx, &slave_config)) { > + dev_err(&as->pdev->dev, > + "failed to configure rx dma channel\n"); > + err = -EINVAL; > + } > + return err; > +} > + > +static int __devinit atmel_spi_configure_dma(struct atmel_spi *as) > +{ > + struct at_dma_slave *sdata = (struct at_dma_slave *)&as->data.dma_slave; > + int err; > + > + slave_config.dst_addr = (dma_addr_t)as->phybase + SPI_TDR; > + slave_config.src_addr = (dma_addr_t)as->phybase + SPI_RDR; > + slave_config.src_maxburst = 1; > + slave_config.dst_maxburst = 1; > + slave_config.device_fc = false; > + > + if (sdata && sdata->dma_dev) { > + dma_cap_mask_t mask; > + > + /* 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) { > + dev_err(&as->pdev->dev, "DMA channel not available, " \ > + "unable to use SPI\n"); > + err = -EBUSY; > + goto error; > + } > + > + err = atmel_spi_set_dma_xfer_width(as, 8); > + if (err) > + goto error; > + > + 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; > +error: > + if (as->dma.chan_rx) > + dma_release_channel(as->dma.chan_rx); > + if (as->dma.chan_tx) > + dma_release_channel(as->dma.chan_tx); > + return err; > +} > + > +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); > +} > + > +/* > + * Submit next transfer for DMA. > + * lock is held, spi tasklet is blocked > + */ > +static int atmel_spi_next_xfer_dma(struct spi_master *master, > + struct spi_transfer *xfer) > +{ > + 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; > + > + dev_vdbg(master->dev.parent, "atmel_spi_next_xfer_dma\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); > + sg_dma_len(&as->dma.sgrx) = xfer->len; > + if (xfer->rx_buf) > + as->dma.sgrx.dma_address = xfer->rx_dma; > + else > + as->dma.sgrx.dma_address = as->buffer_dma; > + > + /* prepare the TX dma transfer */ > + sg_init_table(&as->dma.sgtx, 1); > + sg_dma_len(&as->dma.sgtx) = xfer->len; > + if (xfer->tx_buf) { > + as->dma.sgtx.dma_address = xfer->tx_dma; > + } else { > + as->dma.sgtx.dma_address = as->buffer_dma; > + memset(as->buffer, 0, xfer->len); > + } > + > + if (atmel_spi_set_dma_xfer_width(as, xfer->bits_per_word)) > + goto err_dma; > + > + /* 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, > @@ -364,10 +665,10 @@ 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); > @@ -464,6 +765,44 @@ 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(struct spi_master *master, > + struct spi_message *msg) > +{ > + struct atmel_spi *as = spi_master_get_devdata(master); > + struct spi_transfer *xfer; > + > + dev_vdbg(&msg->spi->dev, "atmel_spi_next_xfer\n"); > + > + if (as->use_pdc) > + atmel_spi_next_xfer_pdc(master, msg); > + 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; > + > + /* quick (and *really* not optimal) workaround for DMA BUG */ > + if (atmel_spi_use_dma(as, xfer) && (xfer->len < BUFFER_SIZE)) { > + if (!atmel_spi_next_xfer_dma(master, xfer)) > + return; > + else > + dev_err(&msg->spi->dev, "unable to use DMA, fallback to PIO\n"); > + } > + > + /* use PIO if xfer is short or 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); > @@ -541,43 +880,218 @@ 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 status, int stay) > + struct spi_message *msg, int stay) > { > - if (!stay || status < 0) > + if (!stay || as->done_status < 0) > cs_deactivate(as, msg->spi); > else > as->stay = msg->spi; > > list_del(&msg->queue); > - msg->status = status; > + msg->status = as->done_status; > > dev_dbg(master->dev.parent, > "xfer complete: %u bytes transferred\n", > msg->actual_length); > > - spin_unlock(&as->lock); > + atmel_spi_unlock(as); > msg->complete(msg->context); > - spin_lock(&as->lock); > + atmel_spi_lock(as); > > as->current_transfer = NULL; > as->next_transfer = NULL; > + 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); > } > > -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; > + u16 *txp16; > + u16 *rxp16; > + unsigned long xfer_pos = xfer->len - as->current_remaining_bytes; > + > + if (xfer->rx_buf) { > + if (xfer->bits_per_word > 8) { > + rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos); > + *rxp16 = spi_readl(as, RDR); > + } else { > + rxp = ((u8 *)xfer->rx_buf) + xfer_pos; > + *rxp = spi_readl(as, RDR); > + } > + } else { > + spi_readl(as, RDR); > + } > + if (xfer->bits_per_word > 8) { > + as->current_remaining_bytes -= 2; > + if (as->current_remaining_bytes < 0) > + as->current_remaining_bytes = 0; > + } else { > + as->current_remaining_bytes--; > + } > + > + if (as->current_remaining_bytes) { > + if (xfer->tx_buf) { > + if (xfer->bits_per_word > 8) { > + txp16 = (u16 *)(((u8 *)xfer->tx_buf) > + + xfer_pos + 2); > + spi_writel(as, TDR, *txp16); > + } else { > + 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->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; > + } > + > + 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 { > + 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(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; > > @@ -610,8 +1124,6 @@ atmel_spi_interrupt(int irq, void *dev_id) > * First, stop the transfer and unmap the DMA buffers. > */ > spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); > - if (!msg->is_dma_mapped) > - atmel_spi_dma_unmap_xfer(master, xfer); > > /* REVISIT: udelay in irq is unfriendly */ > if (xfer->delay_usecs) > @@ -640,7 +1152,8 @@ atmel_spi_interrupt(int irq, void *dev_id) > /* Clear any overrun happening while cleaning up */ > spi_readl(as, SR); > > - atmel_spi_msg_done(master, as, msg, -EIO, 0); > + as->done_status = -EIO; > + atmel_spi_msg_done(master, as, msg, 0); > } else if (pending & (SPI_BIT(RXBUFF) | SPI_BIT(ENDRX))) { > ret = IRQ_HANDLED; > > @@ -649,16 +1162,13 @@ atmel_spi_interrupt(int irq, void *dev_id) > if (as->current_remaining_bytes == 0) { > msg->actual_length += xfer->len; > > - if (!msg->is_dma_mapped) > - atmel_spi_dma_unmap_xfer(master, xfer); > - > /* REVISIT: udelay in irq is unfriendly */ > if (xfer->delay_usecs) > udelay(xfer->delay_usecs); > > if (atmel_spi_xfer_is_last(msg, xfer)) { > /* report completed message */ > - atmel_spi_msg_done(master, as, msg, 0, > + atmel_spi_msg_done(master, as, msg, > xfer->cs_change); > } else { > if (xfer->cs_change) { > @@ -688,6 +1198,27 @@ 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; > @@ -695,7 +1226,7 @@ static int atmel_spi_setup(struct spi_device *spi) > u32 scbr, csr; > unsigned int bits = spi->bits_per_word; > unsigned long bus_hz; > - unsigned int npcs_pin; > + int npcs_pin; > int ret; > > as = spi_master_get_devdata(spi->master); > @@ -718,16 +1249,16 @@ static int atmel_spi_setup(struct spi_device *spi) > } > > /* see notes above re chipselect */ > - if (!atmel_spi_is_v2() > - && spi->chip_select == 0 > - && (spi->mode & SPI_CS_HIGH)) { > + if ((as->data.is_ver2 == 0) > + && spi->chip_select == 0 > + && (spi->mode & SPI_CS_HIGH)) { > dev_dbg(&spi->dev, "setup: can't be active-high\n"); > return -EINVAL; > } > > /* v1 chips start out at half the peripheral bus speed. */ > bus_hz = clk_get_rate(as->clk); > - if (!atmel_spi_is_v2()) > + if (as->data.is_ver2 == 0) > bus_hz /= 2; > > if (spi->max_speed_hz) { > @@ -767,7 +1298,9 @@ static int atmel_spi_setup(struct spi_device *spi) > csr |= SPI_BF(DLYBCT, 0); > > /* chipselect must have been muxed as GPIO (e.g. in board setup) */ > - npcs_pin = (unsigned int)spi->controller_data; > + if (!gpio_is_valid(spi->cs_gpio)) > + spi->cs_gpio = (int)spi->controller_data; > + npcs_pin = spi->cs_gpio; > asd = spi->controller_state; > if (!asd) { > asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); > @@ -784,13 +1317,11 @@ static int atmel_spi_setup(struct spi_device *spi) > spi->controller_state = asd; > gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH)); > } else { > - unsigned long flags; > - > - spin_lock_irqsave(&as->lock, flags); > + atmel_spi_lock(as); > if (as->stay == spi) > as->stay = NULL; > cs_deactivate(as, spi); > - spin_unlock_irqrestore(&as->lock, flags); > + atmel_spi_unlock(as); > } > > asd->csr = csr; > @@ -799,7 +1330,7 @@ static int atmel_spi_setup(struct spi_device *spi) > "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n", > bus_hz / scbr, bits, spi->mode, spi->chip_select, csr); > > - if (!atmel_spi_is_v2()) > + if (as->data.is_ver2 == 0) > spi_writel(as, CSR0 + 4 * spi->chip_select, csr); > > return 0; > @@ -809,7 +1340,6 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) > { > struct atmel_spi *as; > struct spi_transfer *xfer; > - unsigned long flags; > struct device *controller = spi->master->dev.parent; > u8 bits; > struct atmel_spi_device *asd; > @@ -840,6 +1370,12 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) > return -ENOPROTOOPT; > } > } > + if (xfer->bits_per_word > 8) { > + if (xfer->len % 2) { > + dev_dbg(&spi->dev, "buffer len should be 16 bits aligned\n"); > + return -EINVAL; > + } > + } > > /* FIXME implement these protocol options!! */ > if (xfer->speed_hz) { > @@ -849,13 +1385,9 @@ 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)) { > if (atmel_spi_dma_map_xfer(as, xfer) < 0) > return -ENOMEM; > } > @@ -874,11 +1406,11 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) > msg->status = -EINPROGRESS; > msg->actual_length = 0; > > - spin_lock_irqsave(&as->lock, flags); > + atmel_spi_lock(as); > list_add_tail(&msg->queue, &as->queue); > if (!as->current_transfer) > atmel_spi_next_message(spi->master); > - spin_unlock_irqrestore(&as->lock, flags); > + atmel_spi_unlock(as); > > return 0; > } > @@ -887,25 +1419,55 @@ static void atmel_spi_cleanup(struct spi_device *spi) > { > struct atmel_spi *as = spi_master_get_devdata(spi->master); > struct atmel_spi_device *asd = spi->controller_state; > - unsigned gpio = (unsigned) spi->controller_data; > - unsigned long flags; > + unsigned gpio = spi->cs_gpio; > > if (!asd) > return; > > - spin_lock_irqsave(&as->lock, flags); > + atmel_spi_lock(as); > if (as->stay == spi) { > as->stay = NULL; > cs_deactivate(as, spi); > } > - spin_unlock_irqrestore(&as->lock, flags); > + atmel_spi_unlock(as); > > spi->controller_state = NULL; > gpio_free(gpio); > kfree(asd); > } > > -/*-------------------------------------------------------------------------*/ > +static int of_get_atmel_spi_data(struct device_node *np, struct atmel_spi *as) > +{ > + const __be32 *val; > + > + val = of_get_property(np, "has_dma_support", NULL); > + if (!val) { > + pr_err("%s: have no 'has_dma_support' property\n", > + np->full_name); > + return -EINVAL; > + } > + > + as->data.has_dma_support = be32_to_cpup(val); > + > + val = of_get_property(np, "has_pdc_support", NULL); > + if (!val) { > + pr_err("%s: have no 'has_pdc_support' property\n", > + np->full_name); > + return -EINVAL; > + } > + > + as->data.has_pdc_support = be32_to_cpup(val); > + > + val = of_get_property(np, "is_ver2", NULL); > + if (!val) { > + pr_err("%s: have no 'is_ver2' property\n", np->full_name); > + return -EINVAL; > + } > + > + as->data.is_ver2 = be32_to_cpup(val); > + > + return 0; > +} > > static int __devinit atmel_spi_probe(struct platform_device *pdev) > { > @@ -938,7 +1500,8 @@ static int __devinit atmel_spi_probe(struct platform_device *pdev) > master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; > > master->bus_num = pdev->id; > - master->num_chipselect = 4; > + master->dev.of_node = pdev->dev.of_node; > + master->num_chipselect = master->dev.of_node ? 0 : 4; > master->setup = atmel_spi_setup; > master->transfer = atmel_spi_transfer; > master->cleanup = atmel_spi_cleanup; > @@ -957,10 +1520,13 @@ static int __devinit 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) > goto out_free_buffer; > + as->phybase = regs->start; > as->irq = irq; > as->clk = clk; > > @@ -969,12 +1535,22 @@ static int __devinit atmel_spi_probe(struct platform_device *pdev) > if (ret) > goto out_unmap_regs; > > + ret = of_get_atmel_spi_data(pdev->dev.of_node, as); > + if (ret) > + goto out_unmap_regs; > + > + if (as->data.has_dma_support) { > + if (atmel_spi_configure_dma(as) == 0) > + as->use_dma = true; > + } else if (as->data.has_pdc_support) > + as->use_pdc = true; > + > /* Initialize the hardware */ > clk_enable(clk); > spi_writel(as, CR, SPI_BIT(SWRST)); > spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ > spi_writel(as, MR, SPI_BIT(MSTR) | SPI_BIT(MODFDIS)); > - spi_writel(as, PTCR, SPI_BIT(RXTDIS) | SPI_BIT(TXTDIS)); > + > spi_writel(as, CR, SPI_BIT(SPIEN)); > > /* go! */ > @@ -983,11 +1559,14 @@ static int __devinit atmel_spi_probe(struct platform_device *pdev) > > ret = spi_register_master(master); > if (ret) > - goto out_reset_hw; > + goto out_free_dma; > > return 0; > > -out_reset_hw: > +out_free_dma: > + if (as->use_dma) > + atmel_spi_release_dma(as); > + > spi_writel(as, CR, SPI_BIT(SWRST)); > spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ > clk_disable(clk); > @@ -995,6 +1574,7 @@ out_reset_hw: > out_unmap_regs: > iounmap(as->regs); > out_free_buffer: > + tasklet_kill(&as->tasklet); > dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, > as->buffer_dma); > out_free: > @@ -1008,10 +1588,16 @@ static int __devexit atmel_spi_remove(struct platform_device *pdev) > struct spi_master *master = platform_get_drvdata(pdev); > struct atmel_spi *as = spi_master_get_devdata(master); > struct spi_message *msg; > + struct spi_transfer *xfer; > > /* reset the hardware and block queue progress */ > spin_lock_irq(&as->lock); > as->stopping = 1; > + if (as->use_dma) { > + atmel_spi_stop_dma(as); > + atmel_spi_release_dma(as); > + } > + > spi_writel(as, CR, SPI_BIT(SWRST)); > spi_writel(as, CR, SPI_BIT(SWRST)); /* AT91SAM9263 Rev B workaround */ > spi_readl(as, SR); > @@ -1019,13 +1605,15 @@ static int __devexit atmel_spi_remove(struct platform_device *pdev) > > /* Terminate remaining queued transfers */ > list_for_each_entry(msg, &as->queue, queue) { > - /* REVISIT unmapping the dma is a NOP on ARM and AVR32 > - * but we shouldn't depend on that... > - */ > + list_for_each_entry(xfer, &msg->transfers, transfer_list) { > + if (!msg->is_dma_mapped && atmel_spi_use_dma(as, xfer)) > + atmel_spi_dma_unmap_xfer(master, xfer); > + } > msg->status = -ESHUTDOWN; > msg->complete(msg->context); > } > > + tasklet_kill(&as->tasklet); > dma_free_coherent(&pdev->dev, BUFFER_SIZE, as->buffer, > as->buffer_dma); > > @@ -1040,7 +1628,6 @@ static int __devexit atmel_spi_remove(struct platform_device *pdev) > } > > #ifdef CONFIG_PM > - > static int atmel_spi_suspend(struct platform_device *pdev, pm_message_t mesg) > { > struct spi_master *master = platform_get_drvdata(pdev); > @@ -1064,11 +1651,19 @@ static int atmel_spi_resume(struct platform_device *pdev) > #define atmel_spi_resume NULL > #endif > > +#if defined(CONFIG_OF) > +static const struct of_device_id atmel_spi_dt_ids[] = { > + { .compatible = "atmel,at91rm9200-spi" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, atmel_spi_dt_ids); > +#endif > > static struct platform_driver atmel_spi_driver = { > .driver = { > .name = "atmel_spi", > .owner = THIS_MODULE, > + .of_match_table = of_match_ptr(atmel_spi_dt_ids), > }, > .suspend = atmel_spi_suspend, > .resume = atmel_spi_resume, > -- > 1.7.9.5 > > -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |