From patchwork Wed Sep 26 06:50:57 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Wenyou Yang X-Patchwork-Id: 1507881 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 36FEE3FDAE for ; Wed, 26 Sep 2012 06:56:44 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TGlW3-0000IG-Vp; Wed, 26 Sep 2012 06:54:40 +0000 Received: from bombadil.infradead.org ([2001:4830:2446:ff00:4687:fcff:fea6:5117]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TGlVM-0008Ua-00 for linux-arm-kernel@merlin.infradead.org; Wed, 26 Sep 2012 06:53:56 +0000 Received: from newsmtp5.atmel.com ([204.2.163.5] helo=sjogate2.atmel.com) by bombadil.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TGlVI-0007QP-S9 for linux-arm-kernel@lists.infradead.org; Wed, 26 Sep 2012 06:53:55 +0000 Received: from penbh01.corp.atmel.com ([10.168.5.31]) by sjogate2.atmel.com (8.13.6/8.13.6) with ESMTP id q8Q6meNa011239; Tue, 25 Sep 2012 23:48:41 -0700 (PDT) Received: from penmb01.corp.atmel.com ([10.168.5.33]) by penbh01.corp.atmel.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 26 Sep 2012 14:52:09 +0800 Received: from shaarm01.corp.atmel.com ([10.217.6.34]) by penmb01.corp.atmel.com with Microsoft SMTPSVC(6.0.3790.3959); Wed, 26 Sep 2012 14:52:07 +0800 From: Wenyou Yang To: nicolas.ferre@atmel.com Subject: [PATCH 2/6] spi: atmel: add dmaengine and dt support Date: Wed, 26 Sep 2012 14:50:57 +0800 Message-Id: <1348642261-27554-3-git-send-email-wenyou.yang@atmel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1348642261-27554-1-git-send-email-wenyou.yang@atmel.com> References: <1348642261-27554-1-git-send-email-wenyou.yang@atmel.com> MIME-Version: 1.0 X-OriginalArrivalTime: 26 Sep 2012 06:52:08.0590 (UTC) FILETIME=[727DA2E0:01CD9BB3] X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20120926_025353_364300_96C62373 X-CRM114-Status: GOOD ( 29.17 ) X-Spam-Score: -2.7 (--) X-Spam-Report: SpamAssassin version 3.3.2 on bombadil.infradead.org summary: Content analysis details: (-2.7 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.8 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Richard Genoud , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Jean-Christophe PLAGNIOL-VILLARD , linux-arm-kernel@lists.infradead.org, Wenyou Yang X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Signed-off-by: Nicolas Ferre Signed-off-by: Uwe Kleine-König 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@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,