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mtd: spi-nor: add spi_nor_init() function

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This patch extracts some chunks from spi_nor_init_params and spi_nor_scan()
 and moves them into a new spi_nor_init() function.

Indeed, spi_nor_init() regroups all the required SPI flash commands to be
sent to the SPI flash memory before performing any runtime operations
(Fast Read, Page Program, Sector Erase, ...). Hence spi_nor_init():
1) removes the flash protection if applicable for certain vendors.
2) sets the Quad Enable bit, if needed, before using Quad SPI protocols.
3) makes the memory enter its (stateful) 4-byte address mode, if needed,
   for SPI flash memory > 128Mbits not supporting the 4-byte address
   instruction set.

spi_nor_scan() now ends by calling spi_nor_init() once the probe phase has
completed. Further patches could also use spi_nor_init() to implement the
mtd->_resume() handler for the spi-nor framework.

Signed-off-by: Kamal Dasu <kdasu.kdev@gmail.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>
This commit is contained in:
Kamal Dasu 2017-08-22 16:45:21 -04:00 committed by Cyrille Pitchen
parent 90d4fa4540
commit 46dde01f6b
2 changed files with 48 additions and 18 deletions
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56
drivers/mtd/spi-nor/spi-nor.c
View file

@ -2629,14 +2629,44 @@ static int spi_nor_setup(struct spi_nor *nor, const struct flash_info *info,
/* Enable Quad I/O if needed. */
enable_quad_io = (spi_nor_get_protocol_width(nor->read_proto) == 4 ||
spi_nor_get_protocol_width(nor->write_proto) == 4);
if (enable_quad_io && params->quad_enable) {
err = params->quad_enable(nor);
if (enable_quad_io && params->quad_enable)
nor->quad_enable = params->quad_enable;
else
nor->quad_enable = NULL;
return 0;
}
static int spi_nor_init(struct spi_nor *nor)
{
int err;
/*
* Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
* with the software protection bits set
*/
if (JEDEC_MFR(nor->info) == SNOR_MFR_ATMEL ||
JEDEC_MFR(nor->info) == SNOR_MFR_INTEL ||
JEDEC_MFR(nor->info) == SNOR_MFR_SST ||
nor->info->flags & SPI_NOR_HAS_LOCK) {
write_enable(nor);
write_sr(nor, 0);
spi_nor_wait_till_ready(nor);
}
if (nor->quad_enable) {
err = nor->quad_enable(nor);
if (err) {
dev_err(nor->dev, "quad mode not supported\n");
return err;
}
}
if ((nor->addr_width == 4) &&
(JEDEC_MFR(nor->info) != SNOR_MFR_SPANSION) &&
!(nor->info->flags & SPI_NOR_4B_OPCODES))
set_4byte(nor, nor->info, 1);
return 0;
}
@ -2707,20 +2737,6 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
if (ret)
return ret;
/*
* Atmel, SST, Intel/Numonyx, and others serial NOR tend to power up
* with the software protection bits set
*/
if (JEDEC_MFR(info) == SNOR_MFR_ATMEL ||
JEDEC_MFR(info) == SNOR_MFR_INTEL ||
JEDEC_MFR(info) == SNOR_MFR_SST ||
info->flags & SPI_NOR_HAS_LOCK) {
write_enable(nor);
write_sr(nor, 0);
spi_nor_wait_till_ready(nor);
}
if (!mtd->name)
mtd->name = dev_name(dev);
mtd->priv = nor;
@ -2803,8 +2819,6 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
if (JEDEC_MFR(info) == SNOR_MFR_SPANSION ||
info->flags & SPI_NOR_4B_OPCODES)
spi_nor_set_4byte_opcodes(nor, info);
else
set_4byte(nor, info, 1);
} else {
nor->addr_width = 3;
}
@ -2821,6 +2835,12 @@ int spi_nor_scan(struct spi_nor *nor, const char *name,
return ret;
}
/* Send all the required SPI flash commands to initialize device */
nor->info = info;
ret = spi_nor_init(nor);
if (ret)
return ret;
dev_info(dev, "%s (%lld Kbytes)\n", info->name,
(long long)mtd->size >> 10);

10
include/linux/mtd/spi-nor.h
View file

@ -231,11 +231,18 @@ enum spi_nor_option_flags {
SNOR_F_USE_CLSR = BIT(5),
};
/**
* struct flash_info - Forward declaration of a structure used internally by
* spi_nor_scan()
*/
struct flash_info;
/**
* struct spi_nor - Structure for defining a the SPI NOR layer
* @mtd: point to a mtd_info structure
* @lock: the lock for the read/write/erase/lock/unlock operations
* @dev: point to a spi device, or a spi nor controller device.
* @info: spi-nor part JDEC MFR id and other info
* @page_size: the page size of the SPI NOR
* @addr_width: number of address bytes
* @erase_opcode: the opcode for erasing a sector
@ -262,6 +269,7 @@ enum spi_nor_option_flags {
* @flash_lock: [FLASH-SPECIFIC] lock a region of the SPI NOR
* @flash_unlock: [FLASH-SPECIFIC] unlock a region of the SPI NOR
* @flash_is_locked: [FLASH-SPECIFIC] check if a region of the SPI NOR is
* @quad_enable: [FLASH-SPECIFIC] enables SPI NOR quad mode
* completely locked
* @priv: the private data
*/
@ -269,6 +277,7 @@ struct spi_nor {
struct mtd_info mtd;
struct mutex lock;
struct device *dev;
const struct flash_info *info;
u32 page_size;
u8 addr_width;
u8 erase_opcode;
@ -296,6 +305,7 @@ struct spi_nor {
int (*flash_lock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
int (*flash_unlock)(struct spi_nor *nor, loff_t ofs, uint64_t len);
int (*flash_is_locked)(struct spi_nor *nor, loff_t ofs, uint64_t len);
int (*quad_enable)(struct spi_nor *nor);
void *priv;
};