/*
* DMA read/write transfers with ECC support
*/
static int lpc32xx_dma_xfer(struct mtd_info *mtd, uint8_t *buf,
int eccsubpages, int read)
{
struct nand_chip *chip = mtd->priv;
struct lpc32xx_nand_host *host = chip->priv;
uint32_t config, tmpreg;
dma_addr_t buf_phy;
int i, timeout, dma_mapped = 0, status = 0;
/* Map DMA buffer */
if (likely((void *) buf < high_memory)) {
buf_phy = dma_map_single(mtd->dev.parent, buf, mtd->writesize,
read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
if (unlikely(dma_mapping_error(mtd->dev.parent, buf_phy))) {
dev_err(mtd->dev.parent,
"Unable to map DMA buffer\n");
dma_mapped = 0;
} else
dma_mapped = 1;
}
/* If a buffer can't be mapped, use the local buffer */
if (!dma_mapped) {
buf_phy = host->data_buf_dma;
if (!read)
memcpy(host->data_buf, buf, mtd->writesize);
}
if (read)
config = DMAC_CHAN_ITC | DMAC_CHAN_IE | DMAC_CHAN_FLOW_D_P2M |
DMAC_DEST_PERIP (0) |
DMAC_SRC_PERIP(DMA_PERID_NAND1) | DMAC_CHAN_ENABLE;
else
config = DMAC_CHAN_ITC | DMAC_CHAN_IE | DMAC_CHAN_FLOW_D_M2P |
DMAC_DEST_PERIP(DMA_PERID_NAND1) |
DMAC_SRC_PERIP (0) | DMAC_CHAN_ENABLE;
/* DMA mode with ECC enabled */
tmpreg = __raw_readl(SLC_CFG(host->io_base));
__raw_writel(SLCCFG_ECC_EN | SLCCFG_DMA_ECC | tmpreg,
SLC_CFG(host->io_base));
/* Clear initial ECC */
__raw_writel(SLCCTRL_ECC_CLEAR, SLC_CTRL(host->io_base));
/* Prepare DMA descriptors */
lpc32xx_nand_dma_configure(mtd, buf_phy, chip->ecc.steps, read);
/* Setup DMA direction and burst mode */
if (read)
__raw_writel(__raw_readl(SLC_CFG(host->io_base)) |
SLCCFG_DMA_DIR, SLC_CFG(host->io_base));
else
__raw_writel(__raw_readl(SLC_CFG(host->io_base)) &
~SLCCFG_DMA_DIR, SLC_CFG(host->io_base));
__raw_writel(__raw_readl(SLC_CFG(host->io_base)) | SLCCFG_DMA_BURST,
SLC_CFG(host->io_base));
/* Transfer size is data area only */
__raw_writel(mtd->writesize, SLC_TC(host->io_base));
/* Start transfer in the NAND controller */
__raw_writel(__raw_readl(SLC_CTRL(host->io_base)) | SLCCTRL_DMA_START,
SLC_CTRL(host->io_base));
/* Start DMA to process NAND controller DMA FIFO */
host->dmapending = 0;
lpc32xx_dma_start_xfer(host->dmach, config);
/*
* On some systems, the DMA transfer will be very fast, so there is no
* point in waiting for the transfer to complete using the interrupt
* method. It's best to just poll the transfer here to prevent several
* costly context changes. This is especially true for systems that
* use small page devices or NAND devices with very fast access.
*/
if (host->ncfg->polled_completion) {
timeout = LPC32XX_DMA_SIMPLE_TIMEOUT;
while ((timeout > 0) && lpc32xx_dma_is_active(host->dmach))
timeout--;
if (timeout == 0) {
dev_err(mtd->dev.parent,
"DMA transfer timeout error\n");
status = -EIO;
/* Switch to non-polled mode */
host->ncfg->polled_completion = false;
}
}
if (!host->ncfg->polled_completion) {
/* Wait till DMA transfer is done or timeout occurs */
wait_event_timeout(host->dma_waitq, host->dmapending,
msecs_to_jiffies(LPC32XX_DMA_WAIT_TIMEOUT_MS));
if (host->dma_xfer_status != 0) {
dev_err(mtd->dev.parent, "DMA transfer error\n");
status = -EIO;
}
}
/*
* The DMA is finished, but the NAND controller may still have
* buffered data. Wait until all the data is sent.
*/
timeout = LPC32XX_DMA_SIMPLE_TIMEOUT;
while ((__raw_readl(SLC_STAT(host->io_base)) & SLCSTAT_DMA_FIFO)
&& (timeout > 0))
timeout--;
if (timeout == 0) {
dev_err(mtd->dev.parent, "FIFO held data too long\n");
status = -EIO;
}
/* Read last calculated ECC value */
if (read)
host->ecc_buf[chip->ecc.steps - 1] =
__raw_readl(SLC_ECC(host->io_base));
else {
for (i = 0; i < LPC32XX_DMA_ECC_REP_READ; i++)
host->ecc_buf[chip->ecc.steps - 1] =
__raw_readl(SLC_ECC(host->io_base));
}
/*
* For reads, get the OOB data. For writes, the data will be written
* later
*/
if (read)
chip->read_buf(mtd, chip->oob_poi, mtd->oobsize);
/* Flush DMA link list */
lpc32xx_dma_flush_llist(host->dmach);
if (__raw_readl(SLC_STAT(host->io_base)) & SLCSTAT_DMA_FIFO ||
__raw_readl(SLC_TC(host->io_base))) {
/* Something is left in the FIFO, something is wrong */
dev_err(mtd->dev.parent, "DMA FIFO failure\n");
status = -EIO;
}
if (dma_mapped)
dma_unmap_single(mtd->dev.parent, buf_phy, mtd->writesize,
read ? DMA_FROM_DEVICE : DMA_TO_DEVICE);
else if (read)
memcpy(buf, host->data_buf, mtd->writesize);
/* Stop DMA & HW ECC */
__raw_writel(__raw_readl(SLC_CTRL(host->io_base)) &
~SLCCTRL_DMA_START, SLC_CTRL(host->io_base));
__raw_writel(tmpreg, SLC_CFG(host->io_base));
return status;
}
/*
* DMA read/write transfers with ECC support
*/
static int lpc32xx_xfer(struct mtd_info *mtd, uint8_t *buf, int eccsubpages,
int read)
{
struct nand_chip *chip = mtd->priv;
struct lpc32xx_nand_host *host = chip->priv;
int i, status = 0;
unsigned long timeout;
int res;
enum dma_transfer_direction dir =
read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
uint8_t *dma_buf;
bool dma_mapped;
if ((void *)buf <= high_memory) {
dma_buf = buf;
dma_mapped = true;
} else {
dma_buf = host->data_buf;
dma_mapped = false;
if (!read)
memcpy(host->data_buf, buf, mtd->writesize);
}
if (read) {
writel(readl(SLC_CFG(host->io_base)) |
SLCCFG_DMA_DIR | SLCCFG_ECC_EN | SLCCFG_DMA_ECC |
SLCCFG_DMA_BURST, SLC_CFG(host->io_base));
} else {
writel((readl(SLC_CFG(host->io_base)) |
SLCCFG_ECC_EN | SLCCFG_DMA_ECC | SLCCFG_DMA_BURST) &
~SLCCFG_DMA_DIR,
SLC_CFG(host->io_base));
}
/* Clear initial ECC */
writel(SLCCTRL_ECC_CLEAR, SLC_CTRL(host->io_base));
/* Transfer size is data area only */
writel(mtd->writesize, SLC_TC(host->io_base));
/* Start transfer in the NAND controller */
writel(readl(SLC_CTRL(host->io_base)) | SLCCTRL_DMA_START,
SLC_CTRL(host->io_base));
for (i = 0; i < chip->ecc.steps; i++) {
/* Data */
res = lpc32xx_xmit_dma(mtd, SLC_DMA_DATA(host->io_base_dma),
dma_buf + i * chip->ecc.size,
mtd->writesize / chip->ecc.steps, dir);
if (res)
return res;
/* Always _read_ ECC */
if (i == chip->ecc.steps - 1)
break;
if (!read) /* ECC availability delayed on write */
udelay(10);
res = lpc32xx_xmit_dma(mtd, SLC_ECC(host->io_base_dma),
&host->ecc_buf[i], 4, DMA_DEV_TO_MEM);
if (res)
return res;
}
/*
* According to NXP, the DMA can be finished here, but the NAND
* controller may still have buffered data. After porting to using the
* dmaengine DMA driver (amba-pl080), the condition (DMA_FIFO empty)
* appears to be always true, according to tests. Keeping the check for
* safety reasons for now.
*/
if (readl(SLC_STAT(host->io_base)) & SLCSTAT_DMA_FIFO) {
dev_warn(mtd->dev.parent, "FIFO not empty!\n");
timeout = jiffies + msecs_to_jiffies(LPC32XX_DMA_TIMEOUT);
while ((readl(SLC_STAT(host->io_base)) & SLCSTAT_DMA_FIFO) &&
time_before(jiffies, timeout))
cpu_relax();
if (!time_before(jiffies, timeout)) {
dev_err(mtd->dev.parent, "FIFO held data too long\n");
status = -EIO;
}
}
/* Read last calculated ECC value */
if (!read)
udelay(10);
host->ecc_buf[chip->ecc.steps - 1] =
readl(SLC_ECC(host->io_base));
/* Flush DMA */
dmaengine_terminate_all(host->dma_chan);
if (readl(SLC_STAT(host->io_base)) & SLCSTAT_DMA_FIFO ||
readl(SLC_TC(host->io_base))) {
/* Something is left in the FIFO, something is wrong */
dev_err(mtd->dev.parent, "DMA FIFO failure\n");
status = -EIO;
}
/* Stop DMA & HW ECC */
writel(readl(SLC_CTRL(host->io_base)) & ~SLCCTRL_DMA_START,
SLC_CTRL(host->io_base));
writel(readl(SLC_CFG(host->io_base)) &
~(SLCCFG_DMA_DIR | SLCCFG_ECC_EN | SLCCFG_DMA_ECC |
SLCCFG_DMA_BURST), SLC_CFG(host->io_base));
if (!dma_mapped && read)
memcpy(buf, host->data_buf, mtd->writesize);
return status;
}
