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yaml
---
r: 242752
b: refs/heads/master
c: cbc6c5e
h: refs/heads/master
v: v3
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Hong Xu authored and David Woodhouse committed Mar 11, 2011
1 parent 6eec132 commit fcbc3fc
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Showing 2 changed files with 158 additions and 10 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 7f53f12f02b0b60af373a07fcac62b578381308e
refs/heads/master: cbc6c5e73dfa598b1fa5e67cef28096186e2a7cd
166 changes: 157 additions & 9 deletions trunk/drivers/mtd/nand/atmel_nand.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);

Expand Down Expand Up @@ -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.
*/
Expand Down Expand Up @@ -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;

Expand All @@ -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;

Expand All @@ -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
*
Expand Down Expand Up @@ -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");
Expand Down Expand Up @@ -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);
Expand All @@ -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;
Expand Down Expand Up @@ -555,6 +697,8 @@ static int __init atmel_nand_probe(struct platform_device *pdev)
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:
Expand All @@ -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);

Expand Down

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