Re: [PATCH v2 3/4] mtd:spi-nor:fsl-quadspi:Add fast-read mode support

[Han Xu]

On Mon, Feb 01, 2016 at 07:30:07PM +0800, Yunhui Cui wrote:
> The qspi driver add generic fast-read mode for different
> flash venders. There are some different board flash work on
> different mode, such fast-read, quad-mode.
> So we have to modify the third entrace parameter of spi_nor_scan().
> 
> Signed-off-by: Yunhui Cui <B56489@xxxxxxxxxxxxx>
> ---
>  drivers/mtd/spi-nor/fsl-quadspi.c | 27 +++++++++++++++++++++------
>  1 file changed, 21 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/fsl-quadspi.c b/drivers/mtd/spi-nor/fsl-quadspi.c
> index 9861290..0a31cb1 100644
> --- a/drivers/mtd/spi-nor/fsl-quadspi.c
> +++ b/drivers/mtd/spi-nor/fsl-quadspi.c
> @@ -389,11 +389,21 @@ static void fsl_qspi_init_lut(struct fsl_qspi *q)
>  	/* Read */
>  	lut_base = SEQID_READ * 4;
>  
> -	qspi_writel(q, LUT0(CMD, PAD1, read_op) | LUT1(ADDR, PAD1, addrlen),
> -			base + QUADSPI_LUT(lut_base));
> -	qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) |
> -		    LUT1(FSL_READ, PAD4, rxfifo),
> -			base + QUADSPI_LUT(lut_base + 1));
> +	if (nor->flash_read == SPI_NOR_FAST) {
> +		qspi_writel(q, LUT0(CMD, PAD1, read_op) |
> +			    LUT1(ADDR, PAD1, addrlen),
> +				base + QUADSPI_LUT(lut_base));
> +		qspi_writel(q,  LUT0(DUMMY, PAD1, read_dm) |
> +			    LUT1(FSL_READ, PAD1, rxfifo),
> +				base + QUADSPI_LUT(lut_base + 1));
> +	} else if (nor->flash_read == SPI_NOR_QUAD) {
> +		qspi_writel(q, LUT0(CMD, PAD1, read_op) |
> +			    LUT1(ADDR, PAD1, addrlen),
> +				base + QUADSPI_LUT(lut_base));
> +		qspi_writel(q, LUT0(DUMMY, PAD1, read_dm) |
> +			    LUT1(FSL_READ, PAD4, rxfifo),
> +				base + QUADSPI_LUT(lut_base + 1));
> +	}
>  
>  	/* Write enable */
>  	lut_base = SEQID_WREN * 4;
> @@ -468,6 +478,7 @@ static int fsl_qspi_get_seqid(struct fsl_qspi *q, u8 cmd)
>  {
>  	switch (cmd) {
>  	case SPINOR_OP_READ_1_1_4:
> +	case SPINOR_OP_READ_FAST:
>  		return SEQID_READ;
>  	case SPINOR_OP_WREN:
>  		return SEQID_WREN;
> @@ -963,6 +974,7 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>  	struct spi_nor *nor;
>  	struct mtd_info *mtd;
>  	int ret, i = 0;
> +	enum read_mode mode = SPI_NOR_QUAD;
>  
>  	q = devm_kzalloc(dev, sizeof(*q), GFP_KERNEL);
>  	if (!q)
> @@ -1064,7 +1076,10 @@ static int fsl_qspi_probe(struct platform_device *pdev)
>  		/* set the chip address for READID */
>  		fsl_qspi_set_base_addr(q, nor);
>  
> -		ret = spi_nor_scan(nor, NULL, SPI_NOR_QUAD);
> +		ret = of_property_read_bool(np, "m25p,fast-read");
> +		mode = (ret) ? SPI_NOR_FAST : SPI_NOR_QUAD;
> +
> +		ret = spi_nor_scan(nor, NULL, mode);
>  		if (ret)
>  			goto mutex_failed;
>  
I understand you want to provide a more generic read mode, but this is a quad
spi driver, I prefer to provide the options, either quad read/quad IO read,
or just normal read.
> -- 
> 2.1.0.27.g96db324
> 
> 
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