Re: [PATCH v2 2/2] mtd: rawnand: Add timings for Kioxia TH58NVG2S3HBAI4

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

On Wed, 20 May 2020 15:38:54 +0200
Rickard Andersson <rickaran@xxxxxxxx> wrote:

> From: Rickard x Andersson <rickaran@xxxxxxxx>
> 
> The Kioxia/Toshiba TH58NVG2S3HBAI4 NAND memory is not a
> ONFI compliant memory. The timings of the memory is quite
> close to ONFI mode 4 but is breaking that spec.
> 
> Erase block read speed is increased from 6910 KiB/s to
> 13490 KiB/s. 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@xxxxxxxx>
> ---
>  drivers/mtd/nand/raw/nand_ids.c     |  3 ++
>  drivers/mtd/nand/raw/nand_toshiba.c | 66 +++++++++++++++++++++++++++++++++++++
>  2 files changed, 69 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..60ca895b1775 100644
> --- a/drivers/mtd/nand/raw/nand_toshiba.c
> +++ b/drivers/mtd/nand/raw/nand_toshiba.c
> @@ -26,6 +26,52 @@
>  /* Max ECC Steps for BENAND */
>  #define TOSHIBA_NAND_MAX_ECC_STEPS		8
>  
> +static const struct nand_data_interface th58nvg2s3hbai4_timings = {
> +	.type = NAND_SDR_IFACE,
> +	.timings.mode = 0,
> +	.timings.sdr = {
> +		.tPROG_max = 700000000,
> +		.tBERS_max = 5000000000,
> +		.tCCS_min = 500000,
> +		.tR_max = 200000000,
> +		.tADL_min = 400000,
> +		.tALH_min = 5000,
> +		.tALS_min = 12000,
> +		.tAR_min = 10000,
> +		.tCEA_max = 25000,
> +		.tCEH_min = 20000,
> +		.tCH_min = 5000,
> +		.tCHZ_max = 20000,
> +		.tCLH_min = 5000,
> +		.tCLR_min = 10000,
> +		.tCLS_min = 12000,
> +		.tCOH_min = 0,
> +		.tCS_min = 20000,
> +		.tDH_min = 5000,
> +		.tDS_min = 12000,
> +		.tFEAT_max = 1000000,
> +		.tIR_min = 0,
> +		.tITC_max = 1000000,
> +		.tRC_min = 25000,
> +		.tREA_max = 20000,
> +		.tREH_min = 10000,
> +		.tRHOH_min = 25000,
> +		.tRHW_min = 30000,
> +		.tRHZ_max = 60000,
> +		.tRLOH_min = 5000,
> +		.tRP_min = 12000,
> +		.tRR_min = 20000,
> +		.tRST_max = 500000000,
> +		.tWB_max = 100000,
> +		.tWC_min = 25000,
> +		.tWH_min = 10000,
> +		.tWHR_min = 60000,
> +		.tWP_min = 12000,
> +		.tWW_min = 100000,
> +	}
> +};

If we don't want the RO section to grow considerably we should try to
come with a solution to express things in term of deviation from an
existing ONFI timing mode. I'd expect most parameters to match.

> +
> +
>  static int toshiba_nand_benand_read_eccstatus_op(struct nand_chip *chip,
>  						 u8 *buf)
>  {
> @@ -194,6 +240,18 @@ static void toshiba_nand_decode_id(struct nand_chip *chip)
>  	}
>  }
>  
> +static int th58nvg2s3hbai4_choose_data_interface(struct nand_chip *chip)
> +{
> +	int ret;
> +
> +	chip->data_interface = th58nvg2s3hbai4_timings;

Something like:

	/* Start from the closest timing mode. */
	onfi_fill_data_interface(chip, SDR, modeX);

	/* Patch only what you need to patch. */
	chip->data_interface.timings.tXX = YY;

	...
	

> +
> +	/* Check if the controller can handle the timings */
> +	ret = nand_test_data_interface(chip);
> +
> +	return ret;
> +}
> +
>  static int tc58teg5dclta00_init(struct nand_chip *chip)
>  {
>  	struct mtd_info *mtd = nand_to_mtd(chip);
> @@ -205,6 +263,12 @@ static int tc58teg5dclta00_init(struct nand_chip *chip)
>  	return 0;
>  }
>  
> +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 +281,8 @@ static int toshiba_nand_init(struct nand_chip *chip)
>  
>  	if (!strcmp("TC58TEG5DCLTA00", chip->parameters.model))
>  		tc58teg5dclta00_init(chip);
> +	if (!strncmp("TH58NVG2S3HBAI4", chip->parameters.model, 15))
> +		th58nvg2s3hbai4_init(chip);

I think we should add a table with all the chips needing a specific
initialization.

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