From patchwork Tue Jun 2 12:37:56 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Singh, Vimal" X-Patchwork-Id: 27994 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by bilbo.ozlabs.org (Postfix) with ESMTPS id 57A6EB6F56 for ; Tue, 2 Jun 2009 22:43:54 +1000 (EST) Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.69 #1 (Red Hat Linux)) id 1MBTFu-00016Y-78; Tue, 02 Jun 2009 12:38:14 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by bombadil.infradead.org with esmtps (Exim 4.69 #1 (Red Hat Linux)) id 1MBTFl-00014v-NO; Tue, 02 Jun 2009 12:38:12 +0000 Received: from dlep35.itg.ti.com ([157.170.170.118]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id n52Cbvfc003340; Tue, 2 Jun 2009 07:38:02 -0500 Received: from webmail.ti.com (localhost [127.0.0.1]) by dlep35.itg.ti.com (8.13.7/8.13.7) with ESMTP id n52CbrEe017391; Tue, 2 Jun 2009 07:37:55 -0500 (CDT) Received: from 192.168.10.89 (proxying for 10.24.255.17) (SquirrelMail authenticated user x0094262); by dbdmail.itg.ti.com with HTTP; Tue, 2 Jun 2009 18:07:56 +0530 (IST) Message-ID: <54851.192.168.10.89.1243946276.squirrel@dbdmail.itg.ti.com> Date: Tue, 2 Jun 2009 18:07:56 +0530 (IST) Subject: [PATCH] [MTD] [NAND] Add prefetch and dma support for omap2/3 NAND driver From: "vimal singh" To: linux-mtd@lists.infradead.org User-Agent: SquirrelMail/1.4.3a X-Mailer: SquirrelMail/1.4.3a MIME-Version: 1.0 X-Priority: 3 (Normal) Importance: Normal X-Spam-Score: 0.0 (/) Cc: david-b@pacbell.net, dwmw2@infradead.org, linux-kernel@vger.kernel.org X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.11 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-mtd-bounces@lists.infradead.org Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org This patch adds prefetch support to access nand flash in both mpu and dma mode. This patch also adds 8-bit nand support (omap_read/write_buf8). Prefetch can be used for both 8- and 16-bit devices. Signed-off-by: Vimal Singh --- I prepared this patch on top of "OMAP2 / OMAP3 NAND driver" patch: http://lists.infradead.org/pipermail/linux-mtd/2009-May/025562.html --- arch/arm/mach-omap2/gpmc.c | 102 ++++++++++ arch/arm/plat-omap/include/mach/gpmc.h | 4 drivers/mtd/nand/Kconfig | 17 + drivers/mtd/nand/omap2.c | 308 ++++++++++++++++++++++++++++++++- 4 files changed, 422 insertions(+), 9 deletions(-) Index: mtd-2.6/arch/arm/mach-omap2/gpmc.c =================================================================== --- mtd-2.6.orig/arch/arm/mach-omap2/gpmc.c +++ mtd-2.6/arch/arm/mach-omap2/gpmc.c @@ -54,6 +54,12 @@ #define GPMC_CHUNK_SHIFT 24 /* 16 MB */ #define GPMC_SECTION_SHIFT 28 /* 128 MB */ +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH +#define CS_NUM_SHIFT 24 +#define ENABLE_PREFETCH 7 +#define DMA_MPU_MODE 2 +#endif + static struct resource gpmc_mem_root; static struct resource gpmc_cs_mem[GPMC_CS_NUM]; static DEFINE_SPINLOCK(gpmc_mem_lock); @@ -383,6 +389,99 @@ void gpmc_cs_free(int cs) } EXPORT_SYMBOL(gpmc_cs_free); +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH +/** + * gpmc_prefetch_init - configures default configuration for prefetch engine + */ +static void gpmc_prefetch_init(void) +{ + /* Setting the default threshold to 64 */ + gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x0); + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, 0x40 << 8); + gpmc_write_reg(GPMC_PREFETCH_CONFIG2, 0x0); +} + +/** + * gpmc_prefetch_start - configures and starts prefetch transfer + * @cs: nand cs (chip select) number + * @dma_mode: dma mode enable (1) or disable (0) + * @u32_count: number of bytes to be transferred + * @is_write: prefetch read(0) or write post(1) mode + */ +void gpmc_prefetch_start(int cs, int dma_mode, + unsigned int u32_count, int is_write) +{ + uint32_t prefetch_config1; + if (is_write) { + /* Set the amount of bytes to be prefetched */ + gpmc_write_reg(GPMC_PREFETCH_CONFIG2, u32_count); + + /* Set dma/mpu mode, the post write and enable the engine + * Set which cs is using the post write + */ + prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1); + prefetch_config1 |= ((cs << CS_NUM_SHIFT) | + (dma_mode << DMA_MPU_MODE) | + (1 << ENABLE_PREFETCH) | 0x1); + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, prefetch_config1); + } else { + /* Set the amount of bytes to be prefetched */ + gpmc_write_reg(GPMC_PREFETCH_CONFIG2, u32_count); + + /* Set dma/mpu mode, the prefech read and enable the engine + * Set which cs is using the prefetch + */ + prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1); + prefetch_config1 |= (((cs << CS_NUM_SHIFT) | + (dma_mode << DMA_MPU_MODE) | + (1 << ENABLE_PREFETCH)) & ~0x1); + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, prefetch_config1); + } + /* Start the prefetch engine */ + gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x1); +} +EXPORT_SYMBOL(gpmc_prefetch_start); + +/** + * gpmc_prefetch_stop - disables and stops the prefetch engine + */ +void gpmc_prefetch_stop(void) +{ + uint32_t prefetch_config1; + /* stop the PFPW engine */ + gpmc_write_reg(GPMC_PREFETCH_CONTROL, 0x0); + + /* Disable the PFPW engine */ + prefetch_config1 = gpmc_read_reg(GPMC_PREFETCH_CONFIG1); + prefetch_config1 &= ~((0x07 << CS_NUM_SHIFT) | + (1 << ENABLE_PREFETCH) | + (1 << DMA_MPU_MODE) | 0x1); + gpmc_write_reg(GPMC_PREFETCH_CONFIG1, prefetch_config1); +} +EXPORT_SYMBOL(gpmc_prefetch_stop); + +/** + * gpmc_prefetch_status - reads prefetch status of engine + */ +int gpmc_prefetch_status(void) +{ + return gpmc_read_reg(GPMC_PREFETCH_STATUS); +} +EXPORT_SYMBOL(gpmc_prefetch_status); +#else +int gpmc_prefetch_status(void) +{ + return 0; +} +void gpmc_prefetch_stop(void) +{ +} +void gpmc_prefetch_start(int cs, int dma_mode, + unsigned int u32_count, int is_write) +{ +} +#endif + static void __init gpmc_mem_init(void) { int cs; @@ -447,5 +546,8 @@ void __init gpmc_init(void) l |= (0x02 << 3) | (1 << 0); gpmc_write_reg(GPMC_SYSCONFIG, l); +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH + gpmc_prefetch_init(); +#endif gpmc_mem_init(); } Index: mtd-2.6/arch/arm/plat-omap/include/mach/gpmc.h =================================================================== --- mtd-2.6.orig/arch/arm/plat-omap/include/mach/gpmc.h +++ mtd-2.6/arch/arm/plat-omap/include/mach/gpmc.h @@ -103,6 +103,10 @@ extern int gpmc_cs_request(int cs, unsig extern void gpmc_cs_free(int cs); extern int gpmc_cs_set_reserved(int cs, int reserved); extern int gpmc_cs_reserved(int cs); +extern void gpmc_prefetch_start(int cs, int dma_mode, + unsigned int u32_count, int is_write); +extern void gpmc_prefetch_stop(void); +extern int gpmc_prefetch_status(void); extern void __init gpmc_init(void); #endif Index: mtd-2.6/drivers/mtd/nand/Kconfig =================================================================== --- mtd-2.6.orig/drivers/mtd/nand/Kconfig +++ mtd-2.6/drivers/mtd/nand/Kconfig @@ -80,6 +80,23 @@ config MTD_NAND_OMAP2 help Support for NAND flash on Texas Instruments OMAP2 and OMAP3 platforms. +config MTD_NAND_OMAP_PREFETCH + bool "GPMC prefetch support for NAND Flash device" + depends on MTD_NAND && MTD_NAND_OMAP2 + default y + help + The NAND device can be accessed for Read/Write using GPMC PREFETCH engine + to improve the performance. + +config MTD_NAND_OMAP_PREFETCH_DMA + depends on MTD_NAND_OMAP_PREFETCH + bool "DMA mode" + default n + help + The GPMC PREFETCH engine can be configured eigther in MPU interrupt mode + or in DMA interrupt mode. + Say y for DMA mode or MPU mode will be used + config MTD_NAND_TS7250 tristate "NAND Flash device on TS-7250 board" depends on MACH_TS72XX Index: mtd-2.6/drivers/mtd/nand/omap2.c =================================================================== --- mtd-2.6.orig/drivers/mtd/nand/omap2.c +++ mtd-2.6/drivers/mtd/nand/omap2.c @@ -16,8 +16,7 @@ #include #include -#include - +#include #include #include @@ -110,6 +109,27 @@ static const char *part_probes[] = { "cmdlinepart", NULL }; #endif +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH +static int use_prefetch = 1; + +/* "modprobe ... use_prefetch=0" etc */ +module_param(use_prefetch, bool, 0); +MODULE_PARM_DESC(use_prefetch, "enable/disable use of PREFETCH"); + +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH_DMA +static int use_dma = 1; + +/* "modprobe ... use_dma=0" etc */ +module_param(use_dma, bool, 0); +MODULE_PARM_DESC(use_dma, "enable/disable use of DMA"); +#else +const int use_dma; +#endif +#else +const int use_prefetch; +const int use_dma; +#endif + struct omap_nand_info { struct nand_hw_control controller; struct omap_nand_platform_data *pdata; @@ -122,6 +142,9 @@ struct omap_nand_info { unsigned long phys_base; void __iomem *gpmc_cs_baseaddr; void __iomem *gpmc_baseaddr; + void __iomem *nand_pref_fifo_add; + struct completion comp; + int dma_ch; }; /** @@ -187,6 +210,40 @@ static void omap_hwcontrol(struct mtd_in } /** + * omap_read_buf8 - read data from NAND controller into buffer + * @mtd: MTD device structure + * @buf: buffer to store date + * @len: number of bytes to read + */ +static void omap_read_buf8(struct mtd_info *mtd, u_char *buf, int len) +{ + struct nand_chip *nand = mtd->priv; + u_char *p = (u_char *)buf; + + while (len--) + *p++ = __raw_readb(nand->IO_ADDR_R); +} + +/** + * omap_write_buf8 - write buffer to NAND controller + * @mtd: MTD device structure + * @buf: data buffer + * @len: number of bytes to write + */ +static void omap_write_buf8(struct mtd_info *mtd, const u_char *buf, int len) +{ + struct omap_nand_info *info = container_of(mtd, + struct omap_nand_info, mtd); + u_char *p = (u_char *)buf; + + while (len--) { + writeb(*p++, info->nand.IO_ADDR_W); + while (GPMC_BUF_EMPTY == (readl(info->gpmc_baseaddr + + GPMC_STATUS) & GPMC_BUF_FULL)); + } +} + +/** * omap_read_buf16 - read data from NAND controller into buffer * @mtd: MTD device structure * @buf: buffer to store date @@ -222,6 +279,205 @@ static void omap_write_buf16(struct mtd_ ; } } + +#ifdef CONFIG_MTD_NAND_OMAP_PREFETCH_DMA +/** + * omap_nand_dma_cb: callback on the completion of dma transfer + * @lch: logical channel + * @ch_satuts: channel status + * @data: pointer to completion data structure + */ +static void omap_nand_dma_cb(int lch, u16 ch_status, void *data) +{ + complete((struct completion *) data); +} + +/** + * omap_nand_dma_transfer: configer and start dma transfer + * @mtd: MTD device structure + * @addr: virtual address in RAM of source/destination + * @len: number of data bytes to be transferred + * @is_write: flag for read/write operation + */ +static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, + unsigned int len, int is_write) +{ + struct omap_nand_info *info = container_of(mtd, + struct omap_nand_info, mtd); + uint32_t prefetch_status = 0; + enum dma_data_direction dir = is_write ? DMA_TO_DEVICE : + DMA_FROM_DEVICE; + dma_addr_t dma_addr; + + /* The fifo depth is 64 bytes. We have a sync at each frame and frame + * length is 64 bytes. + */ + int buf_len = len/64; + + if (addr >= high_memory) { + struct page *p1; + + if (((size_t)addr & PAGE_MASK) != + ((size_t)(addr + len - 1) & PAGE_MASK)) + goto out_copy; + p1 = vmalloc_to_page(addr); + if (!p1) + goto out_copy; + addr = page_address(p1) + ((size_t)addr & ~PAGE_MASK); + } + + dma_addr = dma_map_single(&info->pdev->dev, addr, len, dir); + if (dma_mapping_error(&info->pdev->dev, dma_addr)) { + dev_err(&info->pdev->dev, + "Couldn't DMA map a %d byte buffer\n", len); + goto out_copy; + } + + if (is_write) { + omap_set_dma_dest_params(info->dma_ch, 0, OMAP_DMA_AMODE_CONSTANT, + info->phys_base, 0, 0); + omap_set_dma_dest_burst_mode(info->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_src_params(info->dma_ch, 0, OMAP_DMA_AMODE_POST_INC, + dma_addr, 0, 0); + omap_set_dma_src_burst_mode(info->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_transfer_params(info->dma_ch, OMAP_DMA_DATA_TYPE_S32, + 0x10, buf_len, OMAP_DMA_SYNC_FRAME, + OMAP24XX_DMA_GPMC, OMAP_DMA_DST_SYNC); + } else { + omap_set_dma_src_params(info->dma_ch, 0, OMAP_DMA_AMODE_CONSTANT, + info->phys_base, 0, 0); + omap_set_dma_src_burst_mode(info->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_dest_params(info->dma_ch, 0, OMAP_DMA_AMODE_POST_INC, + dma_addr, 0, 0); + omap_set_dma_dest_burst_mode(info->dma_ch, OMAP_DMA_DATA_BURST_16); + omap_set_dma_transfer_params(info->dma_ch, OMAP_DMA_DATA_TYPE_S32, + 0x10, buf_len, OMAP_DMA_SYNC_FRAME, + OMAP24XX_DMA_GPMC, OMAP_DMA_SRC_SYNC); + } + /* configure and start prefetch transfer */ + gpmc_prefetch_start(info->gpmc_cs, 0x1, len, is_write); + init_completion(&info->comp); + + omap_start_dma(info->dma_ch); + + /* setup and start DMA using dma_addr */ + wait_for_completion(&info->comp); + + while (0x3fff & (prefetch_status = gpmc_prefetch_status())) + ; + /* disable and stop the PFPW engine */ + gpmc_prefetch_stop(); + + dma_unmap_single(&info->pdev->dev, dma_addr, len, dir); + return 0; + +out_copy: + if (info->nand.options & NAND_BUSWIDTH_16) + is_write == 0 ? omap_read_buf16(mtd, (u_char *) addr, len) + : omap_write_buf16(mtd, (u_char *) addr, len); + else + is_write == 0 ? omap_read_buf8(mtd, (u_char *) addr, len) + : omap_write_buf8(mtd, (u_char *) addr, len); + return 0; +} +#else +static void omap_nand_dma_cb(int lch, u16 ch_status, void *data) +{ +} +static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, + unsigned int len, int is_write) +{ + return 0; +} +#endif + +/** + * omap_read_buf_pref - read data from NAND controller into buffer + * @mtd: MTD device structure + * @buf: buffer to store date + * @len: number of bytes to read + */ +static void omap_read_buf_pref(struct mtd_info *mtd, u_char *buf, int len) +{ + struct omap_nand_info *info = container_of(mtd, + struct omap_nand_info, mtd); + uint32_t prefetch_status = 0, read_count = 0; + u32 *p = (u32 *)buf; + + if ((use_dma && len <= mtd->oobsize) || (!use_dma)) { + + /* take care of subpage reads */ + for (; len % 4 != 0; ) { + *buf++ = __raw_readb(info->nand.IO_ADDR_R); + len--; + } + p = (u32 *) buf; + + /* configure and start prefetch transfer */ + gpmc_prefetch_start(info->gpmc_cs, 0x0, len, 0x0); + + do { + prefetch_status = gpmc_prefetch_status(); + read_count = ((prefetch_status >> 24) & 0x7F) >> 2; + __raw_readsl(info->nand_pref_fifo_add, p, + read_count); + p += read_count; + len -= read_count << 2; + } while (len); + + /* disable and stop the PFPW engine */ + gpmc_prefetch_stop(); + } else if (use_dma) { + if (info->dma_ch >= 0) + /* start transfer in DMA mode */ + omap_nand_dma_transfer(mtd, p, len, 0x0); + } +} + +/** + * omap_write_buf_pref - write buffer to NAND controller + * @mtd: MTD device structure + * @buf: data buffer + * @len: number of bytes to write + */ +static void omap_write_buf_pref(struct mtd_info *mtd, + const u_char *buf, int len) +{ + struct omap_nand_info *info = container_of(mtd, + struct omap_nand_info, mtd); + uint32_t prefetch_status = 0, write_count = 0; + int i = 0; + u16 *p = (u16 *) buf; + + if ((use_dma && len <= mtd->oobsize) || (!use_dma)) { + + /* take care of subpage writes */ + if (len % 2 != 0) { + writeb(*buf, info->nand.IO_ADDR_R); + p = (u16 *)(buf + 1); + len--; + } + + /* configure and start prefetch transfer */ + gpmc_prefetch_start(info->gpmc_cs, 0x0, len, 0x1); + + prefetch_status = gpmc_prefetch_status(); + while (prefetch_status & 0x3FFF) { + write_count = ((prefetch_status >> 24) & 0x7F) >> 1; + for (i = 0; (i < write_count) && len; i++, len -= 2) + __raw_writew(*p++, info->nand_pref_fifo_add); + prefetch_status = gpmc_prefetch_status(); + } + + /* disable and stop the PFPW engine */ + gpmc_prefetch_stop(); + } else if (use_dma) { + if (info->dma_ch >= 0) + /* start transfer in DMA mode */ + omap_nand_dma_transfer(mtd, p, len, 0x1); + } +} + /** * omap_verify_buf - Verify chip data against buffer * @mtd: MTD device structure @@ -655,17 +911,25 @@ static int __devinit omap_nand_probe(str err = -ENOMEM; goto out_release_mem_region; } + + if (use_prefetch) { + /* copy the virtual address of nand base for fifo access */ + info->nand_pref_fifo_add = info->nand.IO_ADDR_R; + if (use_dma) { + err = omap_request_dma(OMAP24XX_DMA_GPMC, "NAND", + omap_nand_dma_cb, &info->comp, &info->dma_ch); + if (err < 0) { + info->dma_ch = -1; + printk(KERN_WARNING "DMA request failed." + " Non-dma data transfer mode\n"); + } + } + } info->nand.controller = &info->controller; info->nand.IO_ADDR_W = info->nand.IO_ADDR_R; info->nand.cmd_ctrl = omap_hwcontrol; - /* REVISIT: only supports 16-bit NAND flash */ - - info->nand.read_buf = omap_read_buf16; - info->nand.write_buf = omap_write_buf16; - info->nand.verify_buf = omap_verify_buf; - /* * If RDY/BSY line is connected to OMAP then use the omap ready * funcrtion and the generic nand_wait function which reads the status @@ -686,6 +950,20 @@ static int __devinit omap_nand_probe(str == 0x1000) info->nand.options |= NAND_BUSWIDTH_16; + if (use_prefetch) { + info->nand.read_buf = omap_read_buf_pref; + info->nand.write_buf = omap_write_buf_pref; + } else { + if (info->nand.options & NAND_BUSWIDTH_16) { + info->nand.read_buf = omap_read_buf16; + info->nand.write_buf = omap_write_buf16; + } else { + info->nand.read_buf = omap_read_buf8; + info->nand.write_buf = omap_write_buf8; + } + } + info->nand.verify_buf = omap_verify_buf; + #ifdef CONFIG_MTD_NAND_OMAP_HWECC info->nand.ecc.bytes = 3; info->nand.ecc.size = 512; @@ -741,9 +1019,12 @@ static int omap_nand_remove(struct platf struct omap_nand_info *info = mtd->priv; platform_set_drvdata(pdev, NULL); + if (use_dma) + omap_free_dma(info->dma_ch); + /* Release NAND device, its internal structures and partitions */ nand_release(&info->mtd); - iounmap(info->nand.IO_ADDR_R); + iounmap(info->nand_pref_fifo_add); kfree(&info->mtd); return 0; } @@ -760,6 +1041,15 @@ static struct platform_driver omap_nand_ static int __init omap_nand_init(void) { printk(KERN_INFO "%s driver initializing\n", DRIVER_NAME); + + /* This check is required if driver is being + * loaded run time as a module + */ + if ((1 == use_dma) && (0 == use_prefetch)) { + printk(KERN_INFO"Wrong parameters: 'use_dma' can not be 1 " + "without use_prefetch'. Prefetch will not be" + " used in either mode (mpu or dma)\n"); + } return platform_driver_register(&omap_nand_driver); }