[PATCH 2/6] mtd: spi-nor: add erase die (chip) capability

[Tudor Ambarus]

On 01.11.2023 11:43, Tudor Ambarus wrote:
> JESD216 defines a chip as a die, one and the other are the same thing.
> JESD216 clarifies that the chip erase time defined in BFPT dword(11)
> applies separately to each die for multi-die devices in which the dice
> are individually accessed. Based on this, update the
> spi_nor_erase_chip() method to support multi-die devices.
> 
> For now, benefit of the die erase when addr and len are aligned with die
> size. This could be improved however for the uniform and non-uniform
> erases cases to use the die erase when possible. For example if one
> requests that an erase of a 2 die device starting from the last 64KB of
> the first die to the end of the flash size, we could use just 2
> commands, a 64KB erase and a die erase. This improvement is left as an
> exercise for the reader, as I don't have multi die flashes at hand.
> 
> Signed-off-by: Tudor Ambarus <tudor.ambarus at linaro.org>
> ---
>  drivers/mtd/spi-nor/core.c    | 22 +++++++++++++++++++---
>  drivers/mtd/spi-nor/core.h    |  6 ++++--
>  drivers/mtd/spi-nor/debugfs.c |  2 +-
>  3 files changed, 24 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c
> index 25a64c65717d..360fce7ffe82 100644
> --- a/drivers/mtd/spi-nor/core.c
> +++ b/drivers/mtd/spi-nor/core.c
> @@ -1067,17 +1067,21 @@ static int spi_nor_read_sr2(struct spi_nor *nor, u8 *sr2)
>   */
>  static int spi_nor_erase_chip(struct spi_nor *nor)
>  {
> +	u8 opcode = nor->params->chip_erase_opcode;
>  	int ret;
>  
>  	dev_dbg(nor->dev, " %lldKiB\n", (long long)(nor->mtd.size >> 10));
>  
>  	if (nor->spimem) {
> -		struct spi_mem_op op = SPI_NOR_CHIP_ERASE_OP;
> +		struct spi_mem_op op = SPI_NOR_CHIP_ERASE_OP(opcode);
>  
>  		spi_nor_spimem_setup_op(nor, &op, nor->reg_proto);
>  
>  		ret = spi_mem_exec_op(nor->spimem, &op);
>  	} else {
> +		if (opcode != SPINOR_OP_CHIP_ERASE)
> +			return -EOPNOTSUPP;
> +
>  		ret = spi_nor_controller_ops_write_reg(nor,
>  						       SPINOR_OP_CHIP_ERASE,
>  						       NULL, 0);
> @@ -1799,7 +1803,10 @@ static int spi_nor_erase_multi_sectors(struct spi_nor *nor, u64 addr, u32 len)
>  static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
>  {
>  	struct spi_nor *nor = mtd_to_spi_nor(mtd);
> +	u8 n_dice = nor->params->n_dice;
> +	bool die_erase = false;
>  	u32 addr, len, rem;
> +	size_t die_size;
>  	int ret;
>  
>  	dev_dbg(nor->dev, "at 0x%llx, len %lld\n", (long long)instr->addr,
> @@ -1814,12 +1821,18 @@ static int spi_nor_erase(struct mtd_info *mtd, struct erase_info *instr)
>  	addr = instr->addr;
>  	len = instr->len;
>  
> +	if (n_dice) {
> +		die_size = div_u64(mtd->size, n_dice);
> +		if (len == die_size && (addr & (die_size - 1)))
> +			die_erase = true;
> +	}
> +
>  	ret = spi_nor_prep_and_lock_pe(nor, instr->addr, instr->len);
>  	if (ret)
>  		return ret;
>  
> -	/* whole-chip erase? */
> -	if (len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) {
> +	/* chip (die) erase? */
> +	if ((len == mtd->size && !(nor->flags & SNOR_F_NO_OP_CHIP_ERASE)) || die_erase) {
>  		unsigned long timeout;
>  
>  		ret = spi_nor_lock_device(nor);
> @@ -2902,6 +2915,9 @@ static int spi_nor_late_init_params(struct spi_nor *nor)
>  			return ret;
>  	}
>  
> +	if (nor->params->chip_erase_opcode)

oops, here I wanted to check for null, when null, set the default.
Takahiro and Fabio, would you please update when/if testing?

	if (!nor->params->chip_erase_opcode)


Thanks!