u-boot-brain/include/spi_flash.h
Simon Glass b3b60f5912 sf: Support querying write-protect
This feature was dropped from U-Boot some time ago:

   f12f96cfaf (sf: Drop spl_flash_get_sw_write_prot")

However, we do need a way to see if a flash device is write-protected,
since if it is, it may not be possible to write to do (i.e. failing to
write is expected).

I am not sure of the correct layer to implement this, so this patch is a
stab at it. If spi-flash makes sense then I will add to the 'sf' also.

Re the points mentioned in the removal commit:

    1) This kind of requirement can be achieved using existing
       flash operations and flash locking API calls instead of
       making a separate flash API.

Which uclass is this?

    2) Technically there is no real hardware user for this API to
       use in the source tree.

I do want coral (at least) to support this.

    3) Having a flash operations API for simple register read bits
       also make difficult to extend the flash operations.

This new patch only mentions write-protect being on or off, rather than
the actual mechanism.

    4) Instead of touching generic code, it is possible to have
       this functionality inside spinor operations in the form of
       flash hooks or fixups for associated flash chips.

That sounds to me like what drivers are for. But we still need some sort
of API for it to be accessible.

Signed-off-by: Simon Glass <sjg@chromium.org>
2021-03-27 15:04:31 +13:00

212 lines
5.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Common SPI flash Interface
*
* Copyright (C) 2008 Atmel Corporation
* Copyright (C) 2013 Jagannadha Sutradharudu Teki, Xilinx Inc.
*/
#ifndef _SPI_FLASH_H_
#define _SPI_FLASH_H_
#include <linux/types.h>
#include <linux/mtd/spi-nor.h>
struct udevice;
/* by default ENV use the same parameters than SF command */
#ifndef CONFIG_ENV_SPI_BUS
# define CONFIG_ENV_SPI_BUS CONFIG_SF_DEFAULT_BUS
#endif
#ifndef CONFIG_ENV_SPI_CS
# define CONFIG_ENV_SPI_CS CONFIG_SF_DEFAULT_CS
#endif
#ifndef CONFIG_ENV_SPI_MAX_HZ
# define CONFIG_ENV_SPI_MAX_HZ CONFIG_SF_DEFAULT_SPEED
#endif
#ifndef CONFIG_ENV_SPI_MODE
# define CONFIG_ENV_SPI_MODE CONFIG_SF_DEFAULT_MODE
#endif
struct spi_slave;
struct dm_spi_flash_ops {
int (*read)(struct udevice *dev, u32 offset, size_t len, void *buf);
int (*write)(struct udevice *dev, u32 offset, size_t len,
const void *buf);
int (*erase)(struct udevice *dev, u32 offset, size_t len);
/**
* get_sw_write_prot() - Check state of software write-protect feature
*
* SPI flash chips can lock a region of the flash defined by a
* 'protected area'. This function checks if this protected area is
* defined.
*
* @dev: SPI flash device
* @return 0 if no region is write-protected, 1 if a region is
* write-protected, -ENOSYS if the driver does not implement this,
* other -ve value on error
*/
int (*get_sw_write_prot)(struct udevice *dev);
};
/* Access the serial operations for a device */
#define sf_get_ops(dev) ((struct dm_spi_flash_ops *)(dev)->driver->ops)
#if CONFIG_IS_ENABLED(DM_SPI_FLASH)
/**
* spi_flash_read_dm() - Read data from SPI flash
*
* @dev: SPI flash device
* @offset: Offset into device in bytes to read from
* @len: Number of bytes to read
* @buf: Buffer to put the data that is read
* @return 0 if OK, -ve on error
*/
int spi_flash_read_dm(struct udevice *dev, u32 offset, size_t len, void *buf);
/**
* spi_flash_write_dm() - Write data to SPI flash
*
* @dev: SPI flash device
* @offset: Offset into device in bytes to write to
* @len: Number of bytes to write
* @buf: Buffer containing bytes to write
* @return 0 if OK, -ve on error
*/
int spi_flash_write_dm(struct udevice *dev, u32 offset, size_t len,
const void *buf);
/**
* spi_flash_erase_dm() - Erase blocks of the SPI flash
*
* Note that @len must be a muiltiple of the flash sector size.
*
* @dev: SPI flash device
* @offset: Offset into device in bytes to start erasing
* @len: Number of bytes to erase
* @return 0 if OK, -ve on error
*/
int spi_flash_erase_dm(struct udevice *dev, u32 offset, size_t len);
/**
* spl_flash_get_sw_write_prot() - Check state of software write-protect feature
*
* SPI flash chips can lock a region of the flash defined by a
* 'protected area'. This function checks if this protected area is
* defined.
*
* @dev: SPI flash device
* @return 0 if no region is write-protected, 1 if a region is
* write-protected, -ENOSYS if the driver does not implement this,
* other -ve value on error
*/
int spl_flash_get_sw_write_prot(struct udevice *dev);
/**
* spi_flash_std_probe() - Probe a SPI flash device
*
* This is the standard internal method for probing a SPI flash device to
* determine its type. It can be used in chip-specific drivers which need to
* do this, typically with of-platdata
*
* @dev: SPI-flash device to probe
* @return 0 if OK, -ve on error
*/
int spi_flash_std_probe(struct udevice *dev);
int spi_flash_probe_bus_cs(unsigned int busnum, unsigned int cs,
unsigned int max_hz, unsigned int spi_mode,
struct udevice **devp);
/* Compatibility function - this is the old U-Boot API */
struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int spi_mode);
/* Compatibility function - this is the old U-Boot API */
static inline void spi_flash_free(struct spi_flash *flash)
{
}
static inline int spi_flash_read(struct spi_flash *flash, u32 offset,
size_t len, void *buf)
{
return spi_flash_read_dm(flash->dev, offset, len, buf);
}
static inline int spi_flash_write(struct spi_flash *flash, u32 offset,
size_t len, const void *buf)
{
return spi_flash_write_dm(flash->dev, offset, len, buf);
}
static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
size_t len)
{
return spi_flash_erase_dm(flash->dev, offset, len);
}
struct sandbox_state;
int sandbox_sf_bind_emul(struct sandbox_state *state, int busnum, int cs,
struct udevice *bus, ofnode node, const char *spec);
void sandbox_sf_unbind_emul(struct sandbox_state *state, int busnum, int cs);
#else
struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int spi_mode);
void spi_flash_free(struct spi_flash *flash);
static inline int spi_flash_read(struct spi_flash *flash, u32 offset,
size_t len, void *buf)
{
struct mtd_info *mtd = &flash->mtd;
size_t retlen;
return mtd->_read(mtd, offset, len, &retlen, buf);
}
static inline int spi_flash_write(struct spi_flash *flash, u32 offset,
size_t len, const void *buf)
{
struct mtd_info *mtd = &flash->mtd;
size_t retlen;
return mtd->_write(mtd, offset, len, &retlen, buf);
}
static inline int spi_flash_erase(struct spi_flash *flash, u32 offset,
size_t len)
{
struct mtd_info *mtd = &flash->mtd;
struct erase_info instr;
if (offset % mtd->erasesize || len % mtd->erasesize) {
printf("SF: Erase offset/length not multiple of erase size\n");
return -EINVAL;
}
memset(&instr, 0, sizeof(instr));
instr.addr = offset;
instr.len = len;
return mtd->_erase(mtd, &instr);
}
#endif
static inline int spi_flash_protect(struct spi_flash *flash, u32 ofs, u32 len,
bool prot)
{
if (!flash->flash_lock || !flash->flash_unlock)
return -EOPNOTSUPP;
if (prot)
return flash->flash_lock(flash, ofs, len);
else
return flash->flash_unlock(flash, ofs, len);
}
#endif /* _SPI_FLASH_H_ */