/* * 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); /* * 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_protection)(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_protection)(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; 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_ */