diff options
Diffstat (limited to 'drivers/mtd/nand/omap2.c')
| -rw-r--r-- | drivers/mtd/nand/omap2.c | 186 |
1 files changed, 184 insertions, 2 deletions
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index 6736822c475..090ab87086b 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -18,8 +18,7 @@ #include <linux/mtd/partitions.h> #include <linux/io.h> -#include <asm/dma.h> - +#include <mach/dma.h> #include <mach/gpmc.h> #include <mach/nand.h> @@ -118,8 +117,19 @@ 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 { @@ -135,6 +145,8 @@ struct omap_nand_info { void __iomem *gpmc_cs_baseaddr; void __iomem *gpmc_baseaddr; void __iomem *nand_pref_fifo_add; + struct completion comp; + int dma_ch; }; /** @@ -355,6 +367,147 @@ static void omap_write_buf_pref(struct mtd_info *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; + int ret; + + /* The fifo depth is 64 bytes. We have a sync at each frame and frame + * length is 64 bytes. + */ + int buf_len = len >> 6; + + 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_src_params(info->dma_ch, 0, OMAP_DMA_AMODE_POST_INC, + dma_addr, 0, 0); + 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_dest_params(info->dma_ch, 0, OMAP_DMA_AMODE_POST_INC, + dma_addr, 0, 0); + 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 */ + ret = gpmc_prefetch_enable(info->gpmc_cs, 0x1, len, is_write); + if (ret) + /* PFPW engine is busy, use cpu copy methode */ + goto out_copy; + + 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_reset(); + + 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_dma_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_dma_pref(struct mtd_info *mtd, u_char *buf, int len) +{ + if (len <= mtd->oobsize) + omap_read_buf_pref(mtd, buf, len); + else + /* start transfer in DMA mode */ + omap_nand_dma_transfer(mtd, buf, len, 0x0); +} + +/** + * omap_write_buf_dma_pref - write buffer to NAND controller + * @mtd: MTD device structure + * @buf: data buffer + * @len: number of bytes to write + */ +static void omap_write_buf_dma_pref(struct mtd_info *mtd, + const u_char *buf, int len) +{ + if (len <= mtd->oobsize) + omap_write_buf_pref(mtd, buf, len); + else + /* start transfer in DMA mode */ + omap_nand_dma_transfer(mtd, buf, len, 0x1); +} + /** * omap_verify_buf - Verify chip data against buffer * @mtd: MTD device structure @@ -821,6 +974,23 @@ static int __devinit omap_nand_probe(struct platform_device *pdev) info->nand.read_buf = omap_read_buf_pref; info->nand.write_buf = omap_write_buf_pref; + 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"); + } else { + omap_set_dma_dest_burst_mode(info->dma_ch, + OMAP_DMA_DATA_BURST_16); + omap_set_dma_src_burst_mode(info->dma_ch, + OMAP_DMA_DATA_BURST_16); + + info->nand.read_buf = omap_read_buf_dma_pref; + info->nand.write_buf = omap_write_buf_dma_pref; + } + } } else { if (info->nand.options & NAND_BUSWIDTH_16) { info->nand.read_buf = omap_read_buf16; @@ -887,6 +1057,9 @@ static int omap_nand_remove(struct platform_device *pdev) 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_pref_fifo_add); @@ -906,6 +1079,15 @@ static struct platform_driver omap_nand_driver = { 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); } |