diff options
| -rw-r--r-- | drivers/mtd/nand/omap2.c | 92 |
1 files changed, 91 insertions, 1 deletions
diff --git a/drivers/mtd/nand/omap2.c b/drivers/mtd/nand/omap2.c index d7f681d0c9b9..2912d6c93635 100644 --- a/drivers/mtd/nand/omap2.c +++ b/drivers/mtd/nand/omap2.c @@ -9,6 +9,7 @@ */ #include <linux/platform_device.h> +#include <linux/dmaengine.h> #include <linux/dma-mapping.h> #include <linux/delay.h> #include <linux/module.h> @@ -18,6 +19,7 @@ #include <linux/mtd/mtd.h> #include <linux/mtd/nand.h> #include <linux/mtd/partitions.h> +#include <linux/omap-dma.h> #include <linux/io.h> #include <linux/slab.h> @@ -123,6 +125,7 @@ struct omap_nand_info { int gpmc_cs; unsigned long phys_base; struct completion comp; + struct dma_chan *dma; int dma_ch; int gpmc_irq; enum { @@ -345,6 +348,10 @@ static void omap_nand_dma_cb(int lch, u16 ch_status, void *data) { complete((struct completion *) data); } +static void omap_nand_dma_callback(void *data) +{ + complete((struct completion *) data); +} /* * omap_nand_dma_transfer: configer and start dma transfer @@ -382,6 +389,56 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, addr = page_address(p1) + ((size_t)addr & ~PAGE_MASK); } + if (info->dma) { + struct dma_async_tx_descriptor *tx; + struct scatterlist sg; + unsigned n; + + sg_init_one(&sg, addr, len); + n = dma_map_sg(info->dma->device->dev, &sg, 1, dir); + if (n == 0) { + dev_err(&info->pdev->dev, + "Couldn't DMA map a %d byte buffer\n", len); + goto out_copy; + } + + tx = dmaengine_prep_slave_sg(info->dma, &sg, n, + is_write ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!tx) { + dma_unmap_sg(info->dma->device->dev, &sg, 1, dir); + goto out_copy; + } + tx->callback = omap_nand_dma_callback; + tx->callback_param = &info->comp; + dmaengine_submit(tx); + + /* configure and start prefetch transfer */ + ret = gpmc_prefetch_enable(info->gpmc_cs, + PREFETCH_FIFOTHRESHOLD_MAX, 0x1, len, is_write); + if (ret) { + /* PFPW engine is busy, use cpu copy method */ + dma_unmap_sg(info->dma->device->dev, &sg, 1, dir); + goto out_copy; + } + + init_completion(&info->comp); + dma_async_issue_pending(info->dma); + + /* setup and start DMA using dma_addr */ + wait_for_completion(&info->comp); + tim = 0; + limit = (loops_per_jiffy * msecs_to_jiffies(OMAP_NAND_TIMEOUT_MS)); + while (gpmc_read_status(GPMC_PREFETCH_COUNT) && (tim++ < limit)) + cpu_relax(); + + /* disable and stop the PFPW engine */ + gpmc_prefetch_reset(info->gpmc_cs); + + dma_unmap_sg(info->dma->device->dev, &sg, 1, dir); + return 0; + } + 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, @@ -414,7 +471,6 @@ static inline int omap_nand_dma_transfer(struct mtd_info *mtd, void *addr, goto out_copy_unmap; init_completion(&info->comp); - omap_start_dma(info->dma_ch); /* setup and start DMA using dma_addr */ @@ -1164,6 +1220,8 @@ static int __devinit omap_nand_probe(struct platform_device *pdev) struct omap_nand_platform_data *pdata; int err; int i, offset; + dma_cap_mask_t mask; + unsigned sig; pdata = pdev->dev.platform_data; if (pdata == NULL) { @@ -1244,6 +1302,33 @@ static int __devinit omap_nand_probe(struct platform_device *pdev) break; case NAND_OMAP_PREFETCH_DMA: + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + sig = OMAP24XX_DMA_GPMC; + info->dma = dma_request_channel(mask, omap_dma_filter_fn, &sig); + if (!info->dma) { + dev_warn(&pdev->dev, "DMA engine request failed\n"); + } else { + struct dma_slave_config cfg; + int rc; + + memset(&cfg, 0, sizeof(cfg)); + cfg.src_addr = info->phys_base; + cfg.dst_addr = info->phys_base; + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + cfg.src_maxburst = 16; + cfg.dst_maxburst = 16; + rc = dmaengine_slave_config(info->dma, &cfg); + if (rc) { + dev_err(&pdev->dev, "DMA engine slave config failed: %d\n", + rc); + goto out_release_mem_region; + } + info->nand.read_buf = omap_read_buf_dma_pref; + info->nand.write_buf = omap_write_buf_dma_pref; + break; + } err = omap_request_dma(OMAP24XX_DMA_GPMC, "NAND", omap_nand_dma_cb, &info->comp, &info->dma_ch); if (err < 0) { @@ -1358,6 +1443,8 @@ static int __devinit omap_nand_probe(struct platform_device *pdev) return 0; out_release_mem_region: + if (info->dma) + dma_release_channel(info->dma); release_mem_region(info->phys_base, NAND_IO_SIZE); out_free_info: kfree(info); @@ -1376,6 +1463,9 @@ static int omap_nand_remove(struct platform_device *pdev) if (info->dma_ch != -1) omap_free_dma(info->dma_ch); + if (info->dma) + dma_release_channel(info->dma); + if (info->gpmc_irq) free_irq(info->gpmc_irq, info); |