[U-Boot] [PATCH] fsl-lsch3: soc: Enable AHB support flexspi controller

[York Sun]

On 09/25/2018 01:44 AM, Ashish Kumar wrote:
> Enable AHB support for flexspi controller interface meaning
> memory can be accessed via md command using absolute addresses
> 
> Signed-off-by: Yogesh Gaur <yogeshnarayan.gaur at nxp.com>
> Signed-off-by: Rajat Srivastava <rajat.srivastava at nxp.com>
> Signed-off-by: Ashish Kumar <Ashish.Kumar at nxp.com>
> ---
>  arch/arm/cpu/armv8/fsl-layerscape/Kconfig | 10 ++++++
>  arch/arm/cpu/armv8/fsl-layerscape/soc.c   | 42 +++++++++++++++++++++++
>  2 files changed, 52 insertions(+)
> 
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> index 5280d33ec8..8d66783b7c 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
> @@ -327,6 +327,16 @@ config SYS_FSPI_AHB_INIT
>  	  performed. Default LUT programmed in AHB mode is Fast Read command
>  	  with 4-byte addressing enabled.
>  
> +config FSPI_AHB_EN_4BYTE
> +	bool "Enable 4-byte Fast Read cmd for AHB mode"

s/cmd/command

> +	depends on NXP_FSPI
> +	default n
> +	help
> +	  The default setting for FSPI AHB bus just supports 3-byte addressing.
> +	  But some FSPI flash sizes are up to 64MBytes.
> +	  This flag enables fast read cmd for AHB mode and modifies required
> +	  LUT to support full FSPI flash.
> +

It is FlexSPI, not FSPI, nor flexspi. Please use consistent term for
FlexSPI in subject, commit message, document and comment. If you have to
use FSPI in macro names, make sure it it has clear meaning.

>  config SYS_CCI400_OFFSET
>  	hex "Offset for CCI400 base"
>  	depends on SYS_FSL_HAS_CCI400
> diff --git a/arch/arm/cpu/armv8/fsl-layerscape/soc.c b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> index 3f15cb08ff..60beb0dc96 100644
> --- a/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> +++ b/arch/arm/cpu/armv8/fsl-layerscape/soc.c
> @@ -640,6 +640,45 @@ void fsl_lsch2_early_init_f(void)
>  }
>  #endif
>  
> +#ifdef CONFIG_FSPI_AHB_EN_4BYTE
> +int fspi_ahb_init(void)
> +{
> +	/* Enable 4bytes address support and fast read */
> +	u32 *fspi_lut, lut_key, *fspi_key;
> +
> +	fspi_key = (void *)SYS_FSL_FSPI_ADDR + 0x18;
> +	fspi_lut = (void *)SYS_FSL_FSPI_ADDR + 0x200;
> +
> +	lut_key = in_be32(fspi_key);
> +
> +	if (lut_key == 0x5af05af0) {
> +		/* That means the register is BE */
> +		out_be32(fspi_key, 0x5af05af0);
> +		/* Unlock the lut table */
> +		out_be32(fspi_key + 1, 0x00000002);
> +		out_be32(fspi_lut, 0x0820040c);
> +		out_be32(fspi_lut + 1, 0x24003008);
> +		out_be32(fspi_lut + 2, 0x00000000);
> +		/* Lock the lut table */
> +		out_be32(fspi_key, 0x5af05af0);
> +		out_be32(fspi_key + 1, 0x00000001);
> +	} else {
> +		/* That means the register is LE */
> +		out_le32(fspi_key, 0x5af05af0);
> +		/* Unlock the lut table */
> +		out_le32(fspi_key + 1, 0x00000002);
> +		out_le32(fspi_lut, 0x0820040c);
> +		out_le32(fspi_lut + 1, 0x24003008);
> +		out_le32(fspi_lut + 2, 0x00000000);
> +		/* Lock the lut table */
> +		out_le32(fspi_key, 0x5af05af0);
> +		out_le32(fspi_key + 1, 0x00000001);

Is there anyway you can make the magic numbers more meaningful?

York