Re: [PATCH v4 19/19] mtd: rawnand: Add timings for Kioxia TH58NVG2S3HBAI4

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

On Mon, 25 May 2020 19:42:39 +0200
Miquel Raynal <miquel.raynal@bootlin.com> wrote:

> From: Rickard x Andersson <rickaran@axis.com>
> 
> The Kioxia/Toshiba TH58NVG2S3HBAI4 NAND memory is not ONFI compliant.
> The timings of the NAND chip memory are quite close to ONFI mode 4 but
> is breaking that spec.
> 
> By providing our own set of timings, erase block read speed is increased
> from 6910 kiB/s to 13490 kiB/s and erase block write speed is increased
> from 3350 kiB/s to 4410 kiB/s.
> 
> Tested on IMX6SX which has a NAND controller supporting EDO mode.
> 
> Signed-off-by: Rickard x Andersson <rickaran@axis.com>
> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
> ---
>  drivers/mtd/nand/raw/nand_ids.c     |  3 +++
>  drivers/mtd/nand/raw/nand_toshiba.c | 38 +++++++++++++++++++++++++++++
>  2 files changed, 41 insertions(+)
> 
> diff --git a/drivers/mtd/nand/raw/nand_ids.c b/drivers/mtd/nand/raw/nand_ids.c
> index e0dbc2e316c7..8b676e8b481b 100644
> --- a/drivers/mtd/nand/raw/nand_ids.c
> +++ b/drivers/mtd/nand/raw/nand_ids.c
> @@ -52,6 +52,9 @@ struct nand_flash_dev nand_flash_ids[] = {
>  		{ .id = {0xad, 0xde, 0x94, 0xda, 0x74, 0xc4} },
>  		  SZ_8K, SZ_8K, SZ_2M, NAND_NEED_SCRAMBLING, 6, 640,
>  		  NAND_ECC_INFO(40, SZ_1K), 4 },
> +	{"TH58NVG2S3HBAI4 4G 3.3V 8-bit",
> +		{ .id = {0x98, 0xdc, 0x91, 0x15, 0x76} },
> +		  SZ_2K, SZ_512, SZ_128K, 0, 5, 128, NAND_ECC_INFO(8, SZ_512) },
>  
>  	LEGACY_ID_NAND("NAND 4MiB 5V 8-bit",   0x6B, 4, SZ_8K, SP_OPTIONS),
>  	LEGACY_ID_NAND("NAND 4MiB 3,3V 8-bit", 0xE3, 4, SZ_8K, SP_OPTIONS),
> diff --git a/drivers/mtd/nand/raw/nand_toshiba.c b/drivers/mtd/nand/raw/nand_toshiba.c
> index b6efaf5195bb..6c79464fdf34 100644
> --- a/drivers/mtd/nand/raw/nand_toshiba.c
> +++ b/drivers/mtd/nand/raw/nand_toshiba.c
> @@ -205,6 +205,42 @@ static int tc58teg5dclta00_init(struct nand_chip *chip)
>  	return 0;
>  }
>  
> +static int th58nvg2s3hbai4_choose_data_interface(struct nand_chip *chip)
> +{
> +	struct nand_data_interface iface;
> +	struct nand_sdr_timings *sdr = &iface.timings.sdr;
> +	int ret;
> +
> +	/* Start with timings from the closest timing mode, mode 4. */
> +	ret = onfi_fill_data_interface(chip, &iface, NAND_SDR_IFACE, 4);
> +	if (ret)
> +		return ret;
> +
> +	/* Patch timings that differ from mode 4. */
> +	sdr->tALS_min = 12000;
> +	sdr->tCHZ_max = 20000;
> +	sdr->tCLS_min = 12000;
> +	sdr->tCOH_min = 0;
> +	sdr->tDS_min = 12000;
> +	sdr->tRHOH_min = 25000;
> +	sdr->tRHW_min = 30000;
> +	sdr->tRHZ_max = 60000;
> +	sdr->tWHR_min = 60000;
> +
> +	/* Patch timings not part of onfi timing mode. */
> +	sdr->tPROG_max = 700000000;
> +	sdr->tBERS_max = 5000000000;

Yay! That's much better than redefining all timings.

> +
> +	return nand_choose_best_vendor_sdr_iface(chip, &iface);
> +}
> +
> +static int th58nvg2s3hbai4_init(struct nand_chip *chip)
> +{
> +	chip->ops.choose_data_interface = th58nvg2s3hbai4_choose_data_interface;
> +
> +	return 0;
> +}
> +
>  static int toshiba_nand_init(struct nand_chip *chip)
>  {
>  	if (nand_is_slc(chip))
> @@ -217,6 +253,8 @@ static int toshiba_nand_init(struct nand_chip *chip)
>  
>  	if (!strcmp("TC58TEG5DCLTA00", chip->parameters.model))
>  		tc58teg5dclta00_init(chip);

As said previously, I'd prefer to have a patch using the same approach
for TC58TEG5DCLTA00.

> +	if (!strncmp("TH58NVG2S3HBAI4", chip->parameters.model, 15))
> +		th58nvg2s3hbai4_init(chip);
>  
>  	return 0;
>  }


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