Re: [PATCH v3 5/6] spi: spi-mtk-nor: support 36bit dma addressing

[Chuanhong Guo <gch981213@xxxxxxxxx>]

Hi!

On Fri, Sep 25, 2020 at 2:56 PM Ikjoon Jang <ikjn@xxxxxxxxxxxx> wrote:
>
> This patch enables 36bit dma address support to spi-mtk-nor.
> Currently this is enabled only for mt8192-nor.
>
> Signed-off-by: Ikjoon Jang <ikjn@xxxxxxxxxxxx>
> ---
>
> (no changes since v1)
>
>  drivers/spi/spi-mtk-nor.c | 18 +++++++++++++++++-
>  1 file changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/spi/spi-mtk-nor.c b/drivers/spi/spi-mtk-nor.c
> index 8dbafee7f431..35205635ed42 100644
> --- a/drivers/spi/spi-mtk-nor.c
> +++ b/drivers/spi/spi-mtk-nor.c
> @@ -78,6 +78,8 @@
>  #define MTK_NOR_REG_DMA_FADR           0x71c
>  #define MTK_NOR_REG_DMA_DADR           0x720
>  #define MTK_NOR_REG_DMA_END_DADR       0x724
> +#define MTK_NOR_REG_DMA_DADR_HB                0x738
> +#define MTK_NOR_REG_DMA_END_DADR_HB    0x73c
>
>  /* maximum bytes of TX in PRG mode */
>  #define MTK_NOR_PRG_MAX_SIZE           6
> @@ -106,6 +108,7 @@ struct mtk_nor {
>         unsigned int spi_freq;
>         bool wbuf_en;
>         bool has_irq;
> +       bool high_dma;
>         struct completion op_done;
>  };
>
> @@ -305,6 +308,11 @@ static int mtk_nor_dma_exec(struct mtk_nor *sp, u32 from, unsigned int length,
>         writel(dma_addr, sp->base + MTK_NOR_REG_DMA_DADR);
>         writel(dma_addr + length, sp->base + MTK_NOR_REG_DMA_END_DADR);
>
> +       if (sp->high_dma) {
> +               writel(dma_addr >> 32, sp->base + MTK_NOR_REG_DMA_DADR_HB);
> +               writel((dma_addr + length) >> 32, sp->base + MTK_NOR_REG_DMA_END_DADR_HB);
> +       }

I remembered kbuild test robot reported a warning on this on 32-bit platforms
in your v1. [0]
I don't know what's the fix for this though :(

[0] https://marc.info/?l=linux-spi&m=159982425706940&w=2
-- 
Regards,
Chuanhong Guo