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/*
* Interface to SPI flash
*
* Copyright (C) 2008 Atmel Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#ifndef _SPI_FLASH_H_
#define _SPI_FLASH_H_
#include <stdint.h>
#include <stddef.h>
#include <spi-generic.h>
#include <boot/coreboot_tables.h>
/* SPI Flash opcodes */
#define SPI_OPCODE_WREN 0x06
#define SPI_OPCODE_FAST_READ 0x0b
struct spi_flash;
/*
* SPI write protection is enforced by locking the status register.
* The following modes are known. It depends on the flash chip if the
* mode is actually supported.
*
* PRESERVE : Keep the previous status register lock-down setting (noop)
* NONE : Status register isn't locked
* PIN : Status register is locked as long as the ~WP pin is active
* REBOOT : Status register is locked until power failure
* PERMANENT: Status register is permanently locked
*/
enum spi_flash_status_reg_lockdown {
SPI_WRITE_PROTECTION_PRESERVE = -1,
SPI_WRITE_PROTECTION_NONE = 0,
SPI_WRITE_PROTECTION_PIN,
SPI_WRITE_PROTECTION_REBOOT,
SPI_WRITE_PROTECTION_PERMANENT
};
/*
* Representation of SPI flash operations:
* read: Flash read operation.
* write: Flash write operation.
* erase: Flash erase operation.
* status: Read flash status register.
*/
struct spi_flash_ops {
int (*read)(const struct spi_flash *flash, u32 offset, size_t len,
void *buf);
int (*write)(const struct spi_flash *flash, u32 offset, size_t len,
const void *buf);
int (*erase)(const struct spi_flash *flash, u32 offset, size_t len);
int (*status)(const struct spi_flash *flash, u8 *reg);
};
/* Current code assumes all callbacks are supplied in this object. */
struct spi_flash_protection_ops {
/*
* Returns 1 if the whole region is software write protected.
* Hardware write protection mechanism aren't accounted.
* If the write protection could be changed, due to unlocked status
* register for example, 0 should be returned.
* Returns 0 on success.
*/
int (*get_write)(const struct spi_flash *flash,
const struct region *region);
/*
* Enable the status register write protection, if supported on the
* requested region, and optionally enable status register lock-down.
* Returns 0 if the whole region was software write protected.
* Hardware write protection mechanism aren't accounted.
* If the status register is locked and the requested configuration
* doesn't match the selected one, return an error.
* Only a single region is supported !
*
* @return 0 on success
*/
int
(*set_write)(const struct spi_flash *flash,
const struct region *region,
const bool non_volatile,
const enum spi_flash_status_reg_lockdown mode);
};
struct spi_flash {
struct spi_slave spi;
u8 vendor;
union {
u8 raw;
struct {
u8 dual_spi : 1;
u8 _reserved : 7;
};
} flags;
u16 model;
const char *name;
u32 size;
u32 sector_size;
u32 page_size;
u8 erase_cmd;
u8 status_cmd;
u8 pp_cmd; /* Page program command. */
u8 wren_cmd; /* Write Enable command. */
const struct spi_flash_ops *ops;
/* If !NULL all protection callbacks exist. */
const struct spi_flash_protection_ops *prot_ops;
const void *driver_private;
};
void lb_spi_flash(struct lb_header *header);
/* SPI Flash Driver Public API */
/*
* Probe for SPI flash chip on given SPI bus and chip select and fill info in
* spi_flash structure.
*
* Params:
* bus = SPI Bus # for the flash chip
* cs = Chip select # for the flash chip
* flash = Pointer to spi flash structure that needs to be filled
*
* Return value:
* 0 = success
* non-zero = error
*/
int spi_flash_probe(unsigned int bus, unsigned int cs, struct spi_flash *flash);
/*
* Generic probing for SPI flash chip based on the different flashes provided.
*
* Params:
* spi = Pointer to spi_slave structure
* flash = Pointer to spi_flash structure that needs to be filled.
*
* Return value:
* 0 = success
* non-zero = error
*/
int spi_flash_generic_probe(const struct spi_slave *slave,
struct spi_flash *flash);
/* All the following functions return 0 on success and non-zero on error. */
int spi_flash_read(const struct spi_flash *flash, u32 offset, size_t len,
void *buf);
int spi_flash_write(const struct spi_flash *flash, u32 offset, size_t len,
const void *buf);
int spi_flash_erase(const struct spi_flash *flash, u32 offset, size_t len);
int spi_flash_status(const struct spi_flash *flash, u8 *reg);
/*
* Return the vendor dependent SPI flash write protection state.
* @param flash : A SPI flash device
* @param region: A subregion of the device's region
*
* Returns:
* -1 on error
* 0 if the device doesn't support block protection
* 0 if the device doesn't enable block protection
* 0 if given range isn't covered by block protection
* 1 if given range is covered by block protection
*/
int spi_flash_is_write_protected(const struct spi_flash *flash,
const struct region *region);
/*
* Enable the vendor dependent SPI flash write protection. The region not
* covered by write-protection will be set to write-able state.
* Only a single write-protected region is supported.
* Some flash ICs require the region to be aligned in the block size, sector
* size or page size.
* Some flash ICs require the region to start at TOP or BOTTOM.
*
* @param flash : A SPI flash device
* @param region: A subregion of the device's region
* @param non_volatile: Write status register non-volatile
* @param mode: Optional lock-down of status register
* @return 0 on success
*/
int
spi_flash_set_write_protected(const struct spi_flash *flash,
const struct region *region,
const bool non_volatile,
const enum spi_flash_status_reg_lockdown mode);
/*
* Some SPI controllers require exclusive access to SPI flash when volatile
* operations like erase or write are being performed. In such cases,
* volatile_group_begin will gain exclusive access to SPI flash if not already
* acquired and volatile_group_end will end exclusive access if this was the
* last request in the group. spi_flash_{write,erase} operations call
* volatile_group_begin at the start of function and volatile_group_end after
* erase/write operation is performed. These functions can also be used by any
* components that wish to club multiple volatile operations into a single
* group.
*/
int spi_flash_volatile_group_begin(const struct spi_flash *flash);
int spi_flash_volatile_group_end(const struct spi_flash *flash);
/*
* These are callbacks for marking the start and end of volatile group as
* handled by the chipset. Not every chipset requires this special handling. So,
* these functions are expected to be implemented in Kconfig option for volatile
* group is enabled (SPI_FLASH_HAS_VOLATILE_GROUP).
*/
int chipset_volatile_group_begin(const struct spi_flash *flash);
int chipset_volatile_group_end(const struct spi_flash *flash);
/* Return spi_flash object reference for the boot device. This is only valid
* if CONFIG_BOOT_DEVICE_SPI_FLASH is enabled. */
const struct spi_flash *boot_device_spi_flash(void);
/* Protect a region of spi flash using its controller, if available. Returns
* < 0 on error, else 0 on success. */
int spi_flash_ctrlr_protect_region(const struct spi_flash *flash,
const struct region *region,
const enum ctrlr_prot_type type);
/*
* This function is provided to support spi flash command-response transactions.
* Only 2 vectors are supported and the 'func' is called with appropriate
* write and read buffers together. This can be used for chipsets that
* have specific spi flash controllers that don't conform to the normal
* spi xfer API because they are specialized controllers and not generic.
*
* Returns 0 on success and non-zero on failure.
*/
int spi_flash_vector_helper(const struct spi_slave *slave,
struct spi_op vectors[], size_t count,
int (*func)(const struct spi_slave *slave, const void *dout,
size_t bytesout, void *din, size_t bytesin));
#endif /* _SPI_FLASH_H_ */