[PATCH] mtd: spi-nor: Add CHIP_ERASE optimization

[Jagan Teki]

On Thu, Mar 2, 2023 at 7:16 AM Marek Vasut <marex at denx.de> wrote:
>
> Add support for CHIP_ERASE opcode 0xc7 . This is useful in case the
> entire SPI NOR is supposed to be erase at once, as is it considerably
> faster than 4k sector erase and even slightly faster than 64k block
> erase. The spi_nor_erase_chip() implementation is adapted from Linux
> 6.1.y as of commit 7d54cb2c26dad ("Linux 6.1.14") . The chip erase is
> only used in case the entire MTD device is being erased, and the chip
> does support this functionality.
>
> Timing figures from W25Q128JW:
> 16 MiB erase using 4kiB sector erase opcode 0x20 ... 107.5s
> 16 MiB erase using 64kiB block erase opcode 0xd8 ... 39.1s
> 16 MiB erase using chip erase opcode 0xc7 .......... 38.7s
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---

Reviewed-by: Jagan Teki <jagan at amarulasolutions.com>

Applied to u-boot-spi/master