// SPDX-License-Identifier: GPL-2.0-or-later /* * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework * * Largely derived from at91_dataflash.c: * Copyright (C) 2003-2005 SAN People (Pty) Ltd */ #include <linux/module.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/mutex.h> #include <linux/err.h> #include <linux/math64.h> #include <linux/of.h> #include <linux/spi/spi.h> #include <linux/spi/flash.h> #include <linux/mtd/mtd.h> #include <linux/mtd/partitions.h> /* * DataFlash is a kind of SPI flash. Most AT45 chips have two buffers in * each chip, which may be used for double buffered I/O; but this driver * doesn't (yet) use these for any kind of i/o overlap or prefetching. * * Sometimes DataFlash is packaged in MMC-format cards, although the * MMC stack can't (yet?) distinguish between MMC and DataFlash * protocols during enumeration. */ /* reads can bypass the buffers */ #define OP_READ_CONTINUOUS … #define OP_READ_PAGE … /* group B requests can run even while status reports "busy" */ #define OP_READ_STATUS … /* move data between host and buffer */ #define OP_READ_BUFFER1 … #define OP_READ_BUFFER2 … #define OP_WRITE_BUFFER1 … #define OP_WRITE_BUFFER2 … /* erasing flash */ #define OP_ERASE_PAGE … #define OP_ERASE_BLOCK … /* move data between buffer and flash */ #define OP_TRANSFER_BUF1 … #define OP_TRANSFER_BUF2 … #define OP_MREAD_BUFFER1 … #define OP_MREAD_BUFFER2 … #define OP_MWERASE_BUFFER1 … #define OP_MWERASE_BUFFER2 … #define OP_MWRITE_BUFFER1 … #define OP_MWRITE_BUFFER2 … /* write to buffer, then write-erase to flash */ #define OP_PROGRAM_VIA_BUF1 … #define OP_PROGRAM_VIA_BUF2 … /* compare buffer to flash */ #define OP_COMPARE_BUF1 … #define OP_COMPARE_BUF2 … /* read flash to buffer, then write-erase to flash */ #define OP_REWRITE_VIA_BUF1 … #define OP_REWRITE_VIA_BUF2 … /* newer chips report JEDEC manufacturer and device IDs; chip * serial number and OTP bits; and per-sector writeprotect. */ #define OP_READ_ID … #define OP_READ_SECURITY … #define OP_WRITE_SECURITY_REVC … #define OP_WRITE_SECURITY … #define CFI_MFR_ATMEL … #define DATAFLASH_SHIFT_EXTID … #define DATAFLASH_SHIFT_ID … struct dataflash { … }; #ifdef CONFIG_OF static const struct of_device_id dataflash_dt_ids[] = …; MODULE_DEVICE_TABLE(of, dataflash_dt_ids); #endif static const struct spi_device_id dataflash_spi_ids[] = …; MODULE_DEVICE_TABLE(spi, dataflash_spi_ids); /* ......................................................................... */ /* * Return the status of the DataFlash device. */ static inline int dataflash_status(struct spi_device *spi) { … } /* * Poll the DataFlash device until it is READY. * This usually takes 5-20 msec or so; more for sector erase. */ static int dataflash_waitready(struct spi_device *spi) { … } /* ......................................................................... */ /* * Erase pages of flash. */ static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr) { … } /* * Read from the DataFlash device. * from : Start offset in flash device * len : Amount to read * retlen : About of data actually read * buf : Buffer containing the data */ static int dataflash_read(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { … } /* * Write to the DataFlash device. * to : Start offset in flash device * len : Amount to write * retlen : Amount of data actually written * buf : Buffer containing the data */ static int dataflash_write(struct mtd_info *mtd, loff_t to, size_t len, size_t * retlen, const u_char * buf) { … } /* ......................................................................... */ #ifdef CONFIG_MTD_DATAFLASH_OTP static int dataflash_get_otp_info(struct mtd_info *mtd, size_t len, size_t *retlen, struct otp_info *info) { … } static ssize_t otp_read(struct spi_device *spi, unsigned base, u8 *buf, loff_t off, size_t len) { … } static int dataflash_read_fact_otp(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { … } static int dataflash_read_user_otp(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, u_char *buf) { … } static int dataflash_write_user_otp(struct mtd_info *mtd, loff_t from, size_t len, size_t *retlen, const u_char *buf) { … } static char *otp_setup(struct mtd_info *device, char revision) { … } #else static char *otp_setup(struct mtd_info *device, char revision) { return " (OTP)"; } #endif /* ......................................................................... */ /* * Register DataFlash device with MTD subsystem. */ static int add_dataflash_otp(struct spi_device *spi, char *name, int nr_pages, int pagesize, int pageoffset, char revision) { … } static inline int add_dataflash(struct spi_device *spi, char *name, int nr_pages, int pagesize, int pageoffset) { … } struct flash_info { … }; static struct flash_info dataflash_data[] = …; static struct flash_info *jedec_lookup(struct spi_device *spi, u64 jedec, bool use_extid) { … } static struct flash_info *jedec_probe(struct spi_device *spi) { … } /* * Detect and initialize DataFlash device, using JEDEC IDs on newer chips * or else the ID code embedded in the status bits: * * Device Density ID code #Pages PageSize Offset * AT45DB011B 1Mbit (128K) xx0011xx (0x0c) 512 264 9 * AT45DB021B 2Mbit (256K) xx0101xx (0x14) 1024 264 9 * AT45DB041B 4Mbit (512K) xx0111xx (0x1c) 2048 264 9 * AT45DB081B 8Mbit (1M) xx1001xx (0x24) 4096 264 9 * AT45DB0161B 16Mbit (2M) xx1011xx (0x2c) 4096 528 10 * AT45DB0321B 32Mbit (4M) xx1101xx (0x34) 8192 528 10 * AT45DB0642 64Mbit (8M) xx111xxx (0x3c) 8192 1056 11 * AT45DB1282 128Mbit (16M) xx0100xx (0x10) 16384 1056 11 */ static int dataflash_probe(struct spi_device *spi) { … } static void dataflash_remove(struct spi_device *spi) { … } static struct spi_driver dataflash_driver = …; module_spi_driver(…) …; MODULE_LICENSE(…) …; MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_ALIAS(…) …;
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