From patchwork Tue Jan 18 06:36:05 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Xu, Hong" X-Patchwork-Id: 79263 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from canuck.infradead.org (canuck.infradead.org [134.117.69.58]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 9A2C3B70FB for ; Tue, 18 Jan 2011 17:40:24 +1100 (EST) Received: from localhost ([127.0.0.1] helo=canuck.infradead.org) by canuck.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1Pf5Ay-0006jh-HI; Tue, 18 Jan 2011 06:36:20 +0000 Received: from newsmtp5.atmel.com ([204.2.163.5] helo=sjogate2.atmel.com) by canuck.infradead.org with esmtp (Exim 4.72 #1 (Red Hat Linux)) id 1Pf5AS-0006ff-Dh; Tue, 18 Jan 2011 06:35:50 +0000 Received: from localhost.localdomain ([10.217.2.49]) by sjogate2.atmel.com (8.13.6/8.13.6) with ESMTP id p0I6X1bg000176; Mon, 17 Jan 2011 22:33:05 -0800 (PST) From: Hong Xu To: linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, jamie@jamieiles.com, jacmet@sunsite.dk, ryan@bluewatersys.com Subject: [PATCH] MTD: atmel_nand: Add DMA support to access Nandflash Date: Tue, 18 Jan 2011 14:36:05 +0800 Message-Id: <1295332565-25610-2-git-send-email-hong.xu@atmel.com> X-Mailer: git-send-email 1.7.3.3 In-Reply-To: References: X-CRM114-Version: 20090807-BlameThorstenAndJenny ( TRE 0.7.6 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20110118_013548_797231_F66D830E X-CRM114-Status: GOOD ( 16.36 ) X-Spam-Score: -0.0 (/) X-Spam-Report: SpamAssassin version 3.3.1 on canuck.infradead.org summary: Content analysis details: (-0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain Cc: hong.xu@atmel.com, nicolas.ferre@atmel.com X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org Some SAM9 chips have the ability to perform DMA between CPU and SMC controller. This patch adds DMA support for SAM9RL, SAM9G45, SSAM9G46,AM9M10, SAM9M11. Signed-off-by: Hong Xu Tested-by: Ryan Mallon Acked-by: Ryan Mallon --- drivers/mtd/nand/atmel_nand.c | 166 ++++++++++++++++++++++++++++++++++++++-- 1 files changed, 157 insertions(+), 9 deletions(-) diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c index ccce0f0..6fae04b 100644 --- a/drivers/mtd/nand/atmel_nand.c +++ b/drivers/mtd/nand/atmel_nand.c @@ -48,6 +48,9 @@ #define no_ecc 0 #endif +static int use_dma = 1; +module_param(use_dma, int, 0); + static int on_flash_bbt = 0; module_param(on_flash_bbt, int, 0); @@ -89,11 +92,20 @@ struct atmel_nand_host { struct nand_chip nand_chip; struct mtd_info mtd; void __iomem *io_base; + dma_addr_t io_phys; struct atmel_nand_data *board; struct device *dev; void __iomem *ecc; + + struct completion comp; + struct dma_chan *dma_chan; }; +static int cpu_has_dma(void) +{ + return cpu_is_at91sam9rl() || cpu_is_at91sam9g45(); +} + /* * Enable NAND. */ @@ -150,7 +162,7 @@ static int atmel_nand_device_ready(struct mtd_info *mtd) /* * Minimal-overhead PIO for data access. */ -static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len) +static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len) { struct nand_chip *nand_chip = mtd->priv; @@ -164,7 +176,7 @@ static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len) __raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2); } -static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len) +static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len) { struct nand_chip *nand_chip = mtd->priv; @@ -178,6 +190,121 @@ static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len) __raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2); } +static void dma_complete_func(void *completion) +{ + complete(completion); +} + +static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len, + int is_read) +{ + struct dma_device *dma_dev; + enum dma_ctrl_flags flags; + dma_addr_t dma_src_addr, dma_dst_addr, phys_addr; + struct dma_async_tx_descriptor *tx = NULL; + dma_cookie_t cookie; + struct nand_chip *chip = mtd->priv; + struct atmel_nand_host *host = chip->priv; + void *p = buf; + int err = -EIO; + enum dma_data_direction dir = is_read ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + + if (buf >= high_memory) { + struct page *pg; + + if (((size_t)buf & PAGE_MASK) != + ((size_t)(buf + len - 1) & PAGE_MASK)) { + dev_warn(host->dev, "Buffer not fit in one page\n"); + goto err_buf; + } + + pg = vmalloc_to_page(buf); + if (pg == 0) { + dev_err(host->dev, "Failed to vmalloc_to_page\n"); + goto err_buf; + } + p = page_address(pg) + ((size_t)buf & ~PAGE_MASK); + } + + dma_dev = host->dma_chan->device; + + flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_SRC_UNMAP | + DMA_COMPL_SKIP_DEST_UNMAP; + + phys_addr = dma_map_single(dma_dev->dev, p, len, dir); + if (dma_mapping_error(dma_dev->dev, phys_addr)) { + dev_err(host->dev, "Failed to dma_map_single\n"); + goto err_buf; + } + + if (is_read) { + dma_src_addr = host->io_phys; + dma_dst_addr = phys_addr; + } else { + dma_src_addr = phys_addr; + dma_dst_addr = host->io_phys; + } + + tx = dma_dev->device_prep_dma_memcpy(host->dma_chan, dma_dst_addr, + dma_src_addr, len, flags); + if (!tx) { + dev_err(host->dev, "Failed to prepare DMA memcpy\n"); + goto err_dma; + } + + init_completion(&host->comp); + tx->callback = dma_complete_func; + tx->callback_param = &host->comp; + + cookie = tx->tx_submit(tx); + if (dma_submit_error(cookie)) { + dev_err(host->dev, "Failed to do DMA tx_submit\n"); + goto err_dma; + } + + dma_async_issue_pending(host->dma_chan); + wait_for_completion(&host->comp); + + err = 0; + +err_dma: + dma_unmap_single(dma_dev->dev, phys_addr, len, dir); +err_buf: + if (err != 0) + dev_warn(host->dev, "Fall back to CPU I/O\n"); + return err; +} + +static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len) +{ + struct nand_chip *chip = mtd->priv; + struct atmel_nand_host *host = chip->priv; + + if (use_dma && len >= mtd->oobsize) + if (atmel_nand_dma_op(mtd, buf, len, 1) == 0) + return; + + if (host->board->bus_width_16) + atmel_read_buf16(mtd, buf, len); + else + atmel_read_buf8(mtd, buf, len); +} + +static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len) +{ + struct nand_chip *chip = mtd->priv; + struct atmel_nand_host *host = chip->priv; + + if (use_dma && len >= mtd->oobsize) + if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0) + return; + + if (host->board->bus_width_16) + atmel_write_buf16(mtd, buf, len); + else + atmel_write_buf8(mtd, buf, len); +} + /* * Calculate HW ECC * @@ -398,6 +525,8 @@ static int __init atmel_nand_probe(struct platform_device *pdev) return -ENOMEM; } + host->io_phys = (dma_addr_t)mem->start; + host->io_base = ioremap(mem->start, mem->end - mem->start + 1); if (host->io_base == NULL) { printk(KERN_ERR "atmel_nand: ioremap failed\n"); @@ -448,14 +577,11 @@ static int __init atmel_nand_probe(struct platform_device *pdev) nand_chip->chip_delay = 20; /* 20us command delay time */ - if (host->board->bus_width_16) { /* 16-bit bus width */ + if (host->board->bus_width_16) /* 16-bit bus width */ nand_chip->options |= NAND_BUSWIDTH_16; - nand_chip->read_buf = atmel_read_buf16; - nand_chip->write_buf = atmel_write_buf16; - } else { - nand_chip->read_buf = atmel_read_buf; - nand_chip->write_buf = atmel_write_buf; - } + + nand_chip->read_buf = atmel_read_buf; + nand_chip->write_buf = atmel_write_buf; platform_set_drvdata(pdev, host); atmel_nand_enable(host); @@ -473,6 +599,22 @@ static int __init atmel_nand_probe(struct platform_device *pdev) nand_chip->options |= NAND_USE_FLASH_BBT; } + if (cpu_has_dma() && use_dma) { + dma_cap_mask_t mask; + + dma_cap_zero(mask); + dma_cap_set(DMA_MEMCPY, mask); + host->dma_chan = dma_request_channel(mask, 0, NULL); + if (!host->dma_chan) { + dev_err(host->dev, "Failed to request DMA channel\n"); + use_dma = 0; + } + } + if (use_dma) + dev_info(host->dev, "Using DMA for NAND access.\n"); + else + dev_info(host->dev, "No DMA support for NAND access.\n"); + /* first scan to find the device and get the page size */ if (nand_scan_ident(mtd, 1, NULL)) { res = -ENXIO; @@ -555,6 +697,8 @@ err_scan_ident: err_no_card: atmel_nand_disable(host); platform_set_drvdata(pdev, NULL); + if (host->dma_chan) + dma_release_channel(host->dma_chan); if (host->ecc) iounmap(host->ecc); err_ecc_ioremap: @@ -578,6 +722,10 @@ static int __exit atmel_nand_remove(struct platform_device *pdev) if (host->ecc) iounmap(host->ecc); + + if (host->dma_chan) + dma_release_channel(host->dma_chan); + iounmap(host->io_base); kfree(host);