Re: [PATCH v5] mtd: sunxi-nand: enable mdma support for allwinner a23

[Boris Brezillon <boris.brezillon@collabora.com>]

Hello Manuel,

The subject prefix should be "mtd: rawnand: sunxi:" not "mtd:
sunxi-nand:"

On Thu, 8 Oct 2020 16:58:47 +0200 (CEST)
Manuel Dipolt <mdipolt@robart.cc> wrote:

> This patch enables nand mdma mode for the Allwinner socs A23/A33/H3

		     ^NAND MDMA (Master DMA)

And you need a period at the of your sentence.

> 
> Signed-off-by: Manuel Dipolt <manuel.dipolt@robart.cc>
> ---
>  drivers/mtd/nand/raw/sunxi_nand.c | 156 +++++++++++++++++++-----------
>  1 file changed, 101 insertions(+), 55 deletions(-)
> 
> diff --git a/drivers/mtd/nand/raw/sunxi_nand.c b/drivers/mtd/nand/raw/sunxi_nand.c
> index 2a7ca3072f35..8403785e85e1 100644
> --- a/drivers/mtd/nand/raw/sunxi_nand.c
> +++ b/drivers/mtd/nand/raw/sunxi_nand.c
> @@ -51,6 +51,7 @@
>  #define NFC_REG_USER_DATA(x)	(0x0050 + ((x) * 4))
>  #define NFC_REG_SPARE_AREA	0x00A0
>  #define NFC_REG_PAT_ID		0x00A4
> +#define NFC_REG_MDMA_ADDR	0x00C0
>  #define NFC_REG_MDMA_CNT	0x00C4
>  #define NFC_RAM0_BASE		0x0400
>  #define NFC_RAM1_BASE		0x0800
> @@ -207,13 +208,13 @@ static inline struct sunxi_nand_chip *to_sunxi_nand(struct nand_chip *nand)
>   * NAND Controller capabilities structure: stores NAND controller capabilities
>   * for distinction between compatible strings.
>   *
> - * @extra_mbus_conf:	Contrary to A10, A10s and A13, accessing internal RAM
> + * @has_mdma:		Use mbus dma mode, otherwise general dma
>   *			through MBUS on A23/A33 needs extra configuration.
>   * @reg_io_data:	I/O data register
>   * @dma_maxburst:	DMA maxburst
>   */
>  struct sunxi_nfc_caps {
> -	bool extra_mbus_conf;
> +	bool has_mdma;
>  	unsigned int reg_io_data;
>  	unsigned int dma_maxburst;
>  };
> @@ -346,7 +347,7 @@ static int sunxi_nfc_rst(struct sunxi_nfc *nfc)
>  static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
>  				    int chunksize, int nchunks,
>  				    enum dma_data_direction ddir,
> -				    struct scatterlist *sg)
> +				    struct scatterlist *sg, dma_addr_t *mem_addr)

You don't need to pass the mem_addr, it will be extracted from the sg
list.

>  {
>  	struct dma_async_tx_descriptor *dmad;
>  	enum dma_transfer_direction tdir;
> @@ -358,29 +359,46 @@ static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
>  	else
>  		tdir = DMA_MEM_TO_DEV;
>  
> -	sg_init_one(sg, buf, nchunks * chunksize);
> -	ret = dma_map_sg(nfc->dev, sg, 1, ddir);
> -	if (!ret)
> -		return -ENOMEM;
> +	if (nfc->caps->has_mdma) {
> +		*mem_addr = dma_map_single(nfc->dev, (void *)buf, nchunks * chunksize, tdir);
> +		ret = dma_mapping_error(nfc->dev, *mem_addr);

You can use sg_init_one() here as well.

> +		if (ret) {
> +			dev_err(nfc->dev, "DMA mapping error\n");
> +			return ret;
> +		}
> +	} else {
> +		sg_init_one(sg, buf, nchunks * chunksize);
> +		ret = dma_map_sg(nfc->dev, sg, 1, ddir);
> +		if (!ret)
> +			return -ENOMEM;
>  
> -	dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
> -	if (!dmad) {
> -		ret = -EINVAL;
> -		goto err_unmap_buf;
> +		dmad = dmaengine_prep_slave_sg(nfc->dmac, sg, 1, tdir, DMA_CTRL_ACK);
> +		if (!dmad) {
> +			ret = -EINVAL;
> +			goto err_unmap_buf;
> +		}
>  	}
>  
>  	writel(readl(nfc->regs + NFC_REG_CTL) | NFC_RAM_METHOD,
>  	       nfc->regs + NFC_REG_CTL);
>  	writel(nchunks, nfc->regs + NFC_REG_SECTOR_NUM);
>  	writel(chunksize, nfc->regs + NFC_REG_CNT);
> -	if (nfc->caps->extra_mbus_conf)
> +
> +	if (nfc->caps->has_mdma) {
> +		writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_DMA_TYPE_NORMAL,
> +		       nfc->regs + NFC_REG_CTL);
>  		writel(chunksize * nchunks, nfc->regs + NFC_REG_MDMA_CNT);
> +		writel(*mem_addr, nfc->regs + NFC_REG_MDMA_ADDR);

			^ sg_dma_address(sg)

> +	} else {
> +		writel(readl(nfc->regs + NFC_REG_CTL) | NFC_DMA_TYPE_NORMAL,
> +		       nfc->regs + NFC_REG_CTL);
>  
> -	dmat = dmaengine_submit(dmad);
> +		dmat = dmaengine_submit(dmad);
>  
> -	ret = dma_submit_error(dmat);
> -	if (ret)
> -		goto err_clr_dma_flag;
> +		ret = dma_submit_error(dmat);
> +		if (ret)
> +			goto err_clr_dma_flag;
> +	}
>  
>  	return 0;
>  
> @@ -395,11 +413,24 @@ static int sunxi_nfc_dma_op_prepare(struct sunxi_nfc *nfc, const void *buf,
>  
>  static void sunxi_nfc_dma_op_cleanup(struct sunxi_nfc *nfc,
>  				     enum dma_data_direction ddir,
> -				     struct scatterlist *sg)
> +				     struct scatterlist *sg, dma_addr_t mem_addr, size_t size)
>  {
> -	dma_unmap_sg(nfc->dev, sg, 1, ddir);
> -	writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
> -	       nfc->regs + NFC_REG_CTL);
> +	enum dma_transfer_direction tdir;
> +
> +	if (ddir == DMA_FROM_DEVICE)
> +		tdir = DMA_DEV_TO_MEM;
> +	else
> +		tdir = DMA_MEM_TO_DEV;
> +
> +	if (nfc->caps->has_mdma) {
> +		dma_unmap_single(nfc->dev, mem_addr, size, tdir);
> +		writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
> +		       nfc->regs + NFC_REG_CTL);
> +	} else {
> +		dma_unmap_sg(nfc->dev, sg, 1, ddir);
> +		writel(readl(nfc->regs + NFC_REG_CTL) & ~NFC_RAM_METHOD,
> +		       nfc->regs + NFC_REG_CTL);
> +	}
>  }

As I said in my previous review, if you get rid of the mem_addr
argument, you shouldn't need any changes to this function. Have you
tried using sg_dma_address()?

Regards,

Boris

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