From patchwork Mon Jul 16 12:09:55 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Vasut X-Patchwork-Id: 1200731 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 07481E0038 for ; Mon, 16 Jul 2012 12:17:10 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1SqkBp-0003JV-L7; Mon, 16 Jul 2012 12:14:13 +0000 Received: from mail-out.m-online.net ([212.18.0.10]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1Sqk80-0002qX-OL for linux-arm-kernel@lists.infradead.org; Mon, 16 Jul 2012 12:10:35 +0000 Received: from frontend4.mail.m-online.net (frontend1.mail.intern.m-online.net [192.168.8.180]) by mail-out.m-online.net (Postfix) with ESMTP id 3WbNlL1MS6z3hhdq; Mon, 16 Jul 2012 14:11:42 +0200 (CEST) Received: from mashiro.lan (unknown [195.140.253.167]) by smtp-auth.mnet-online.de (Postfix) with ESMTPA id 3WbNjg239XzbbrY; Mon, 16 Jul 2012 14:10:15 +0200 (CEST) From: Marek Vasut To: spi-devel-general@lists.sourceforge.net Subject: [PATCH 08/10] spi: Add DMA support into SPI driver Date: Mon, 16 Jul 2012 14:09:55 +0200 Message-Id: <1342440597-8395-9-git-send-email-marex@denx.de> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1342440597-8395-1-git-send-email-marex@denx.de> References: <1342440597-8395-1-git-send-email-marex@denx.de> X-Spam-Note: CRM114 invocation failed X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at http://www.dnswl.org/, no trust [212.18.0.10 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Marek Vasut , Fabio Estevam , Shawn Guo , Wolfgang Denk , Detlev Zundel , Stefano Babic , attila@kinali.ch, Grant Likely , Rob Herring , Chris Ball , Dong Aisheng , Linux ARM kernel 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: , MIME-Version: 1.0 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: Marek Vasut Cc: Chris Ball Cc: Detlev Zundel CC: Dong Aisheng Cc: Fabio Estevam Cc: Grant Likely Cc: Linux ARM kernel Cc: Rob Herring CC: Shawn Guo Cc: Stefano Babic Cc: Wolfgang Denk --- drivers/spi/spi-mxs.c | 230 +++++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 215 insertions(+), 15 deletions(-) diff --git a/drivers/spi/spi-mxs.c b/drivers/spi/spi-mxs.c index a7d2ebc..e90200f 100644 --- a/drivers/spi/spi-mxs.c +++ b/drivers/spi/spi-mxs.c @@ -55,8 +55,12 @@ #define SSP_TIMEOUT 1000 /* 1000 ms */ +#define SG_NUM 4 +#define SG_MAXLEN 0xff00 + struct mxs_spi { struct mxs_ssp ssp; + struct completion c; }; static int mxs_spi_setup_transfer(struct spi_device *dev, @@ -192,6 +196,115 @@ static int mxs_ssp_wait(struct mxs_spi *spi, int offset, int mask, bool set) return 0; } +static void mxs_ssp_dma_irq_callback(void *param) +{ + struct mxs_spi *spi = param; + complete(&spi->c); +} + +static irqreturn_t mxs_ssp_irq_handler(int irq, void *dev_id) +{ + struct mxs_ssp *ssp = dev_id; + dev_err(ssp->dev, "%s[%i] CTRL1=%08x STATUS=%08x\n", + __func__, __LINE__, + readl(ssp->base + HW_SSP_CTRL1(ssp)), + readl(ssp->base + HW_SSP_STATUS(ssp))); + return IRQ_HANDLED; +} + +static int mxs_spi_txrx_dma(struct mxs_spi *spi, int cs, + unsigned char *buf, int len, + int *first, int *last, int write) +{ + struct mxs_ssp *ssp = &spi->ssp; + struct dma_async_tx_descriptor *desc; + struct scatterlist sg[SG_NUM]; + int sg_count; + uint32_t pio = BM_SSP_CTRL0_DATA_XFER | mxs_spi_cs_to_reg(cs); + int ret; + + if (len > SG_NUM * SG_MAXLEN) { + dev_err(ssp->dev, "Data chunk too big for DMA\n"); + return -EINVAL; + } + + init_completion(&spi->c); + + if (*first) + pio |= BM_SSP_CTRL0_LOCK_CS; + if (*last) + pio |= BM_SSP_CTRL0_IGNORE_CRC; + if (!write) + pio |= BM_SSP_CTRL0_READ; + + if (ssp->devid == IMX23_SSP) + pio |= len; + else + writel(len, ssp->base + HW_SSP_XFER_SIZE); + + /* Queue the PIO register write transfer. */ + desc = dmaengine_prep_slave_sg(ssp->dmach, + (struct scatterlist *)&pio, + 1, DMA_TRANS_NONE, 0); + if (!desc) { + dev_err(ssp->dev, + "Failed to get PIO reg. write descriptor.\n"); + return -EINVAL; + } + + /* Queue the DMA data transfer. */ + sg_init_table(sg, (len / SG_MAXLEN) + 1); + sg_count = 0; + while (len) { + sg_set_buf(&sg[sg_count++], buf, min(len, SG_MAXLEN)); + len -= min(len, SG_MAXLEN); + buf += min(len, SG_MAXLEN); + } + dma_map_sg(ssp->dev, sg, sg_count, + write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); + + desc = dmaengine_prep_slave_sg(ssp->dmach, sg, sg_count, + write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + + if (!desc) { + dev_err(ssp->dev, + "Failed to get DMA data write descriptor.\n"); + ret = -EINVAL; + goto err; + } + + /* + * The last descriptor must have this callback, + * to finish the DMA transaction. + */ + desc->callback = mxs_ssp_dma_irq_callback; + desc->callback_param = spi; + + /* Start the transfer. */ + dmaengine_submit(desc); + dma_async_issue_pending(ssp->dmach); + + ret = wait_for_completion_timeout(&spi->c, + msecs_to_jiffies(SSP_TIMEOUT)); + + if (!ret) { + dev_err(ssp->dev, "DMA transfer timeout\n"); + ret = -ETIMEDOUT; + goto err; + } + + ret = 0; + +err: + for (--sg_count; sg_count >= 0; sg_count--) { + dma_unmap_sg(ssp->dev, &sg[sg_count], 1, + write ? DMA_TO_DEVICE : DMA_FROM_DEVICE); + } + + return ret; +} + static int mxs_spi_txrx_pio(struct mxs_spi *spi, int cs, unsigned char *buf, int len, int *first, int *last, int write) @@ -276,18 +389,48 @@ static int mxs_spi_transfer_one(struct spi_master *host, struct spi_message *m) first = 1; if (&t->transfer_list == m->transfers.prev) last = 1; - if (t->rx_buf && t->tx_buf) { + if ((t->rx_buf && t->tx_buf) || (t->rx_dma && t->tx_dma)) { dev_err(ssp->dev, "Cannot send and receive simultaneously\n"); return -EINVAL; } - if (t->tx_buf) - status = mxs_spi_txrx_pio(spi, cs, (void *)t->tx_buf, - t->len, &first, &last, 1); - if (t->rx_buf) - status = mxs_spi_txrx_pio(spi, cs, t->rx_buf, - t->len, &first, &last, 0); + /* + * Small blocks can be transfered via PIO. + * Measured by empiric means: + * + * dd if=/dev/mtdblock0 of=/dev/null bs=1024k count=1 + * + * DMA only: 2.164808 seconds, 473.0KB/s + * Combined: 1.676276 seconds, 610.9KB/s + */ + if (t->len <= 256) { + writel(BM_SSP_CTRL1_DMA_ENABLE, + ssp->base + HW_SSP_CTRL1(ssp) + + STMP_OFFSET_REG_CLR); + + if (t->tx_buf) + status = mxs_spi_txrx_pio(spi, cs, + (void *)t->tx_buf, + t->len, &first, &last, 1); + if (t->rx_buf) + status = mxs_spi_txrx_pio(spi, cs, + t->rx_buf, t->len, + &first, &last, 0); + } else { + writel(BM_SSP_CTRL1_DMA_ENABLE, + ssp->base + HW_SSP_CTRL1(ssp) + + STMP_OFFSET_REG_SET); + + if (t->tx_buf) + status = mxs_spi_txrx_dma(spi, cs, + (void *)t->tx_buf, t->len, + &first, &last, 1); + if (t->rx_buf) + status = mxs_spi_txrx_dma(spi, cs, + t->rx_buf, t->len, + &first, &last, 0); + } m->actual_length += t->len; if (status) @@ -302,6 +445,21 @@ static int mxs_spi_transfer_one(struct spi_master *host, struct spi_message *m) return status; } +static bool mxs_ssp_dma_filter(struct dma_chan *chan, void *param) +{ + struct mxs_ssp *ssp = param; + + if (!mxs_dma_is_apbh(chan)) + return false; + + if (chan->chan_id != ssp->dma_channel) + return false; + + chan->private = &ssp->dma_data; + + return true; +} + static const struct of_device_id mxs_spi_dt_ids[] = { { .compatible = "fsl,imx23-spi", .data = (void *) IMX23_SSP, }, { .compatible = "fsl,imx28-spi", .data = (void *) IMX28_SSP, }, @@ -317,15 +475,18 @@ static int __devinit mxs_spi_probe(struct platform_device *pdev) struct spi_master *host; struct mxs_spi *spi; struct mxs_ssp *ssp; - struct resource *iores; + struct resource *iores, *dmares; struct pinctrl *pinctrl; struct clk *clk; void __iomem *base; - int devid; - int ret = 0; + int devid, dma_channel; + int ret = 0, irq_err, irq_dma; + dma_cap_mask_t mask; iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!iores) + irq_err = platform_get_irq(pdev, 0); + irq_dma = platform_get_irq(pdev, 1); + if (!iores || irq_err < 0 || irq_dma < 0) return -EINVAL; base = devm_request_and_ioremap(&pdev->dev, iores); @@ -340,10 +501,26 @@ static int __devinit mxs_spi_probe(struct platform_device *pdev) if (IS_ERR(clk)) return PTR_ERR(clk); - if (np) + if (np) { devid = (enum mxs_ssp_id) of_id->data; - else + /* + * TODO: This is a temporary solution and should be changed + * to use generic DMA binding later when the helpers get in. + */ + ret = of_property_read_u32(np, "fsl,ssp-dma-channel", + &dma_channel); + if (ret) { + dev_err(&pdev->dev, + "Failed to get DMA channel\n"); + return -EINVAL; + } + } else { + dmares = platform_get_resource(pdev, IORESOURCE_DMA, 0); + if (!dmares) + return -EINVAL; devid = pdev->id_entry->driver_data; + dma_channel = dmares->start; + } host = spi_alloc_master(&pdev->dev, sizeof(*spi)); if (!host) @@ -363,8 +540,28 @@ static int __devinit mxs_spi_probe(struct platform_device *pdev) ssp->clk = clk; ssp->base = base; ssp->devid = devid; + ssp->dma_channel = dma_channel; + + ret = devm_request_irq(&pdev->dev, irq_err, mxs_ssp_irq_handler, 0, + DRIVER_NAME, ssp); + if (ret) + goto out_host_free; + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + ssp->dma_data.chan_irq = irq_dma; + ssp->dmach = dma_request_channel(mask, mxs_ssp_dma_filter, ssp); + if (!ssp->dmach) { + dev_err(ssp->dev, "Failed to request DMA\n"); + goto out_host_free; + } + + /* + * Crank up the clock to 120MHz, this will be further divided onto a + * proper speed. + */ clk_prepare_enable(ssp->clk); + clk_set_rate(ssp->clk, 120 * 1000 * 1000); ssp->clk_rate = clk_get_rate(ssp->clk) / 1000; stmp_reset_block(ssp->base); @@ -374,15 +571,18 @@ static int __devinit mxs_spi_probe(struct platform_device *pdev) ret = spi_register_master(host); if (ret) { dev_err(&pdev->dev, "Cannot register SPI master, %d\n", ret); - goto out_host_free; + goto out_free_dma; } return 0; -out_host_free: +out_free_dma: + dma_release_channel(ssp->dmach); clk_disable_unprepare(ssp->clk); +out_host_free: spi_master_put(host); kfree(host); + return ret; }