From afd473e8582702e89aed89a4be957ffd37423009 Mon Sep 17 00:00:00 2001 From: Pratyush Yadav Date: Tue, 1 Dec 2020 15:57:10 +0530 Subject: [PATCH] mtd: spi-nor: core: Allow flashes to specify MTD writesize Some flashes like the Cypress S28 family use ECC. Under this ECC scheme, multi-pass writes to an ECC block is not allowed. In other words, once data is programmed to an ECC block, it can't be programmed again without erasing it first. Upper layers like file systems need to be given this information so they do not cause error conditions on the flash by attempting multi-pass programming. This can be done by setting 'writesize' in 'struct mtd_info'. Set the default to 1 but allow flashes to modify it in fixup hooks. If more flashes show up with this constraint in the future it might be worth it to add it to 'struct flash_info', but for now increasing its size is not worth it. Signed-off-by: Pratyush Yadav Signed-off-by: Vignesh Raghavendra Reviewed-by: Tudor Ambarus Link: https://lore.kernel.org/r/20201201102711.8727-3-p.yadav@ti.com --- drivers/mtd/spi-nor/core.c | 3 ++- drivers/mtd/spi-nor/core.h | 3 +++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 7b4850f942233..ae991ff458a09 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -2885,6 +2885,7 @@ static void spi_nor_info_init_params(struct spi_nor *nor) nor->flags |= SNOR_F_HAS_16BIT_SR; /* Set SPI NOR sizes. */ + params->writesize = 1; params->size = (u64)info->sector_size * info->n_sectors; params->page_size = info->page_size; @@ -3430,7 +3431,7 @@ int spi_nor_scan(struct spi_nor *nor, const char *name, mtd->name = dev_name(dev); mtd->priv = nor; mtd->type = MTD_NORFLASH; - mtd->writesize = 1; + mtd->writesize = nor->params->writesize; mtd->flags = MTD_CAP_NORFLASH; mtd->size = nor->params->size; mtd->_erase = spi_nor_erase; diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 0a775a7b56061..5ab3f269a23cc 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -193,6 +193,8 @@ struct spi_nor_locking_ops { * Serial Flash Discoverable Parameters (SFDP) tables. * * @size: the flash memory density in bytes. + * @writesize Minimal writable flash unit size. Defaults to 1. Set to + * ECC unit size for ECC-ed flashes. * @page_size: the page size of the SPI NOR flash memory. * @rdsr_dummy: dummy cycles needed for Read Status Register command. * @rdsr_addr_nbytes: dummy address bytes needed for Read Status Register @@ -219,6 +221,7 @@ struct spi_nor_locking_ops { */ struct spi_nor_flash_parameter { u64 size; + u32 writesize; u32 page_size; u8 rdsr_dummy; u8 rdsr_addr_nbytes; -- 2.30.2