On Sun, 27 Nov 2016 03:06:07 +0900
Masahiro Yamada <yamada.masah...@socionext.com> wrote:
> The current driver only supports the DMA engine up to 32 bit
> physical address, but there also exists 64 bit capable DMA engine
> for this IP.
>
> The data DMA setup sequence is completely different, so I added the
> 64 bit DMA code as a new function denali_setup_dma64(). The 32 bit
> one has been renamed to denali_setup_dma32().
>
> Signed-off-by: Masahiro Yamada <yamada.masah...@socionext.com>
> ---
>
> drivers/mtd/nand/denali.c | 39 +++++++++++++++++++++++++++++++++++----
> drivers/mtd/nand/denali.h | 1 +
> 2 files changed, 36 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mtd/nand/denali.c b/drivers/mtd/nand/denali.c
> index ae44c01..752ad98 100644
> --- a/drivers/mtd/nand/denali.c
> +++ b/drivers/mtd/nand/denali.c
> @@ -995,8 +995,30 @@ static void denali_enable_dma(struct denali_nand_info
> *denali, bool en)
> ioread32(denali->flash_reg + DMA_ENABLE);
> }
>
> -/* setups the HW to perform the data DMA */
> -static void denali_setup_dma(struct denali_nand_info *denali, int op)
> +static void denali_setup_dma64(struct denali_nand_info *denali, int op)
> +{
> + u32 mode;
> + const int page_count = 1;
> + u64 addr = denali->buf.dma_buf;
> +
> + mode = MODE_10 | BANK(denali->flash_bank) | denali->page;
> +
> + /* DMA is a three step process */
> +
> + /*
> + * 1. setup transfer type, interrupt when complete,
> + * burst len = 64 bytes, the number of pages
> + */
> + index_addr(denali, mode, 0x01002000 | (64 << 16) | op | page_count);
> +
> + /* 2. set memory low address */
> + index_addr(denali, mode, addr);
> +
> + /* 3. set memory high address */
> + index_addr(denali, mode, addr >> 32);
> +}
> +
> +static void denali_setup_dma32(struct denali_nand_info *denali, int op)
> {
> u32 mode;
> const int page_count = 1;
> @@ -1019,6 +1041,14 @@ static void denali_setup_dma(struct denali_nand_info
> *denali, int op)
> index_addr(denali, mode | 0x14000, 0x2400);
> }
>
> +static void denali_setup_dma(struct denali_nand_info *denali, int op)
> +{
> + if (denali->caps & DENALI_CAPS_DMA_64BIT)
> + denali_setup_dma64(denali, op);
> + else
> + denali_setup_dma32(denali, op);
> +}
> +
If you follow my suggestions of definition function pointers, you'll
just have to add a function pointer to the denali_caps struct:
void (*setup_dma)(struct denali_nand_info *denali, int op);
> /*
> * writes a page. user specifies type, and this function handles the
> * configuration details.
> @@ -1495,8 +1525,9 @@ int denali_init(struct denali_nand_info *denali)
> goto failed_req_irq;
> }
>
> - /* Is 32-bit DMA supported? */
> - ret = dma_set_mask(denali->dev, DMA_BIT_MASK(32));
> + ret = dma_set_mask(denali->dev,
> + DMA_BIT_MASK(denali->caps & DENALI_CAPS_DMA_64BIT ?
> + 64 : 32));
> if (ret) {
> dev_err(denali->dev, "no usable DMA configuration\n");
> goto failed_req_irq;
> diff --git a/drivers/mtd/nand/denali.h b/drivers/mtd/nand/denali.h
> index beadc8a..9bdf037 100644
> --- a/drivers/mtd/nand/denali.h
> +++ b/drivers/mtd/nand/denali.h
> @@ -435,6 +435,7 @@ struct denali_nand_info {
> u32 max_banks;
> unsigned int caps;
> #define DENALI_CAPS_HW_ECC_FIXUP BIT(0)
> +#define DENALI_CAPS_DMA_64BIT BIT(1)
> };
>
> extern int denali_init(struct denali_nand_info *denali);
