[U-Boot] [PATCH v1 3/7] nand: add nand mtd concat support

[Scott Wood]

On 05/25/2016 12:07 AM, Heiko Schocher wrote:
> add for nand devices mtd concat support. Generic MTD concat
> support is already ported to mainline, and used in the cfi_mtd
> driver. This patch adds it similiar for nand devices.
> 
> Signed-off-by: Heiko Schocher <hs at denx.de>
> ---
> 
>  drivers/mtd/nand/nand.c | 29 +++++++++++++++++++++++++++++
>  1 file changed, 29 insertions(+)
> 
> diff --git a/drivers/mtd/nand/nand.c b/drivers/mtd/nand/nand.c
> index 8f0a921..5413123 100644
> --- a/drivers/mtd/nand/nand.c
> +++ b/drivers/mtd/nand/nand.c
> @@ -9,6 +9,7 @@
>  #include <common.h>
>  #include <nand.h>
>  #include <errno.h>
> +#include <linux/mtd/concat.h>
>  
>  #ifndef CONFIG_SYS_NAND_BASE_LIST
>  #define CONFIG_SYS_NAND_BASE_LIST { CONFIG_SYS_NAND_BASE }
> @@ -30,6 +31,12 @@ static char dev_name[CONFIG_SYS_MAX_NAND_DEVICE][8];
>  
>  static unsigned long total_nand_size; /* in kiB */
>  
> +#ifdef CONFIG_MTD_CONCAT
> +static int nand_devices_found;
> +static struct mtd_info *mtd_nand_list[CONFIG_SYS_MAX_NAND_DEVICE];
> +static char c_mtd_name[16];
> +#endif

Why is c_mtd_name file-scope rather than local?

> +
>  /* Register an initialized NAND mtd device with the U-Boot NAND command. */
>  int nand_register(int devnum)
>  {
> @@ -49,6 +56,9 @@ int nand_register(int devnum)
>  	 * via the mtdcore infrastructure (e.g. ubi).
>  	 */
>  	add_mtd_device(mtd);
> +#ifdef CONFIG_MTD_CONCAT
> +	mtd_nand_list[nand_devices_found++] = mtd;
> +#endif

Why do we need another list of NAND devices?  Use nand_info[].

>  #endif
>  
>  	total_nand_size += mtd->size / 1024;
> @@ -102,4 +112,23 @@ void nand_init(void)
>  	 */
>  	board_nand_select_device(nand_info[nand_curr_device].priv, nand_curr_device);
>  #endif
> +
> +#ifdef CONFIG_MTD_CONCAT
> +	if (nand_devices_found > 1) {
> +		struct mtd_info *mtd;
> +
> +		/*
> +		 * We detected multiple devices. Concatenate them together.
> +		 */
> +		sprintf(c_mtd_name, "nand%d", nand_devices_found);
> +		mtd = mtd_concat_create(mtd_nand_list, nand_devices_found,
> +					c_mtd_name);
> +
> +		if (mtd == NULL)
> +			return;
> +
> +		if (add_mtd_device(mtd))
> +			return;
> +	}
> +#endif /* CONFIG_MTD_CONCAT */
>  }

Please don't add new features that depend on the old-style NAND init.

-Scott