/* * Atmel AT45xxx DataFlash MTD driver for lightweight SPI framework * * Largely derived from at91_dataflash.c: * Copyright (C) 2003-2005 SAN People (Pty) Ltd * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include #include #include #include #include #include #include #include #include #include /* * 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 use SPI (yet), or distinguish between MMC and DataFlash * protocols during enumeration. */ #define CONFIG_DATAFLASH_WRITE_VERIFY /* reads can bypass the buffers */ #define OP_READ_CONTINUOUS 0xE8 #define OP_READ_PAGE 0xD2 /* group B requests can run even while status reports "busy" */ #define OP_READ_STATUS 0xD7 /* group B */ /* move data between host and buffer */ #define OP_READ_BUFFER1 0xD4 /* group B */ #define OP_READ_BUFFER2 0xD6 /* group B */ #define OP_WRITE_BUFFER1 0x84 /* group B */ #define OP_WRITE_BUFFER2 0x87 /* group B */ /* erasing flash */ #define OP_ERASE_PAGE 0x81 #define OP_ERASE_BLOCK 0x50 /* move data between buffer and flash */ #define OP_TRANSFER_BUF1 0x53 #define OP_TRANSFER_BUF2 0x55 #define OP_MREAD_BUFFER1 0xD4 #define OP_MREAD_BUFFER2 0xD6 #define OP_MWERASE_BUFFER1 0x83 #define OP_MWERASE_BUFFER2 0x86 #define OP_MWRITE_BUFFER1 0x88 /* sector must be pre-erased */ #define OP_MWRITE_BUFFER2 0x89 /* sector must be pre-erased */ /* write to buffer, then write-erase to flash */ #define OP_PROGRAM_VIA_BUF1 0x82 #define OP_PROGRAM_VIA_BUF2 0x85 /* compare buffer to flash */ #define OP_COMPARE_BUF1 0x60 #define OP_COMPARE_BUF2 0x61 /* read flash to buffer, then write-erase to flash */ #define OP_REWRITE_VIA_BUF1 0x58 #define OP_REWRITE_VIA_BUF2 0x59 /* newer chips report JEDEC manufacturer and device IDs; chip * serial number and OTP bits; and per-sector writeprotect. */ #define OP_READ_ID 0x9F #define OP_READ_SECURITY 0x77 #define OP_WRITE_SECURITY 0x9A /* OTP bits */ struct dataflash { u8 command[4]; char name[24]; unsigned partitioned:1; unsigned short page_offset; /* offset in flash address */ unsigned int page_size; /* of bytes per page */ struct semaphore lock; struct spi_device *spi; struct mtd_info mtd; }; #ifdef CONFIG_MTD_PARTITIONS #define mtd_has_partitions() (1) #else #define mtd_has_partitions() (0) #endif /* ......................................................................... */ /* * Return the status of the DataFlash device. */ static inline int dataflash_status(struct spi_device *spi) { /* NOTE: at45db321c over 25 MHz wants to write * a dummy byte after the opcode... */ return spi_w8r8(spi, OP_READ_STATUS); } /* * 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) { int status; for (;;) { status = dataflash_status(spi); if (status < 0) { DEBUG(MTD_DEBUG_LEVEL1, "%s: status %d?\n", spi->dev.bus_id, status); status = 0; } if (status & (1 << 7)) /* RDY/nBSY */ return status; msleep(3); } } /* ......................................................................... */ /* * Erase pages of flash. */ static int dataflash_erase(struct mtd_info *mtd, struct erase_info *instr) { struct dataflash *priv = (struct dataflash *)mtd->priv; struct spi_device *spi = priv->spi; struct spi_transfer x = { .tx_dma = 0, }; struct spi_message msg; unsigned blocksize = priv->page_size << 3; u8 *command; DEBUG(MTD_DEBUG_LEVEL2, "%s: erase addr=0x%x len 0x%x\n", spi->dev.bus_id, instr->addr, instr->len); /* Sanity checks */ if ((instr->addr + instr->len) > mtd->size || (instr->len % priv->page_size) != 0 || (instr->addr % priv->page_size) != 0) return -EINVAL; spi_message_init(&msg); x.tx_buf = command = priv->command; x.len = 4; spi_message_add_tail(&x, &msg); down(&priv->lock); while (instr->len > 0) { unsigned int pageaddr; int status; int do_block; /* Calculate flash page address; use block erase (for speed) if * we're at a block boundary and need to erase the whole block. */ pageaddr = instr->addr / priv->page_size; do_block = (pageaddr & 0x7) == 0 && instr->len >= blocksize; pageaddr = pageaddr << priv->page_offset; command[0] = do_block ? OP_ERASE_BLOCK : OP_ERASE_PAGE; command[1] = (u8)(pageaddr >> 16); command[2] = (u8)(pageaddr >> 8); command[3] = 0; DEBUG(MTD_DEBUG_LEVEL3, "ERASE %s: (%x) %x %x %x [%i]\n", do_block ? "block" : "page", command[0], command[1], command[2], command[3], pageaddr); status = spi_sync(spi, &msg); (void) dataflash_waitready(spi); if (status < 0) { printk(KERN_ERR "%s: erase %x, err %d\n", spi->dev.bus_id, pageaddr, status); /* REVISIT: can retry instr->retries times; or * giveup and instr->fail_addr = instr->addr; */ continue; } if (do_block) { instr->addr += blocksize; instr->len -= blocksize; } else { instr->addr += priv->page_size; instr->len -= priv->page_size; } } up(&priv->lock); /* Inform MTD subsystem that erase is complete */ instr->state = MTD_ERASE_DONE; mtd_erase_callback(instr); return 0; } /* * 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) { struct dataflash *priv = (struct dataflash *)mtd->priv; struct spi_transfer x[2] = { { .tx_dma = 0, }, }; struct spi_message msg; unsigned int addr; u8 *command; int status; DEBUG(MTD_DEBUG_LEVEL2, "%s: read 0x%x..0x%x\n", priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len)); *retlen = 0; /* Sanity checks */ if (!len) return 0; if (from + len > mtd->size) return -EINVAL; /* Calculate flash page/byte address */ addr = (((unsigned)from / priv->page_size) << priv->page_offset) + ((unsigned)from % priv->page_size); command = priv->command; DEBUG(MTD_DEBUG_LEVEL3, "READ: (%x) %x %x %x\n", command[0], command[1], command[2], command[3]); spi_message_init(&msg); x[0].tx_buf = command; x[0].len = 8; spi_message_add_tail(&x[0], &msg); x[1].rx_buf = buf; x[1].len = len; spi_message_add_tail(&x[1], &msg); down(&priv->lock); /* Continuous read, max clock = f(car) which may be less than * the peak rate available. Some chips support commands with * fewer "don't care" bytes. Both buffers stay unchanged. */ command[0] = OP_READ_CONTINUOUS; command[1] = (u8)(addr >> 16); command[2] = (u8)(addr >> 8); command[3] = (u8)(addr >> 0); /* plus 4 "don't care" bytes */ status = spi_sync(priv->spi, &msg); up(&priv->lock); if (status >= 0) { *retlen = msg.actual_length - 8; status = 0; } else DEBUG(MTD_DEBUG_LEVEL1, "%s: read %x..%x --> %d\n", priv->spi->dev.bus_id, (unsigned)from, (unsigned)(from + len), status); return status; } /* * 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) { struct dataflash *priv = (struct dataflash *)mtd->priv; struct spi_device *spi = priv->spi; struct spi_transfer x[2] = { { .tx_dma = 0, }, }; struct spi_message msg; unsigned int pageaddr, addr, offset, writelen; size_t remaining = len; u_char *writebuf = (u_char *) buf; int status = -EINVAL; u8 *command; DEBUG(MTD_DEBUG_LEVEL2, "%s: write 0x%x..0x%x\n", spi->dev.bus_id, (unsigned)to, (unsigned)(to + len)); *retlen = 0; /* Sanity checks */ if (!len) return 0; if ((to + len) > mtd->size) return -EINVAL; spi_message_init(&msg); x[0].tx_buf = command = priv->command; x[0].len = 4; spi_message_add_tail(&x[0], &msg); pageaddr = ((unsigned)to / priv->page_size); offset = ((unsigned)to % priv->page_size); if (offset + len > priv->page_size) writelen = priv->page_size - offset; else writelen = len; down(&priv->lock); while (remaining > 0) { DEBUG(MTD_DEBUG_LEVEL3, "write @ %i:%i len=%i\n", pageaddr, offset, writelen); /* REVISIT: * (a) each page in a sector must be rewritten at least * once every 10K sibling erase/program operations. * (b) for pages that are already erased, we could * use WRITE+MWRITE not PROGRAM for ~30% speedup. * (c) WRITE to buffer could be done while waiting for * a previous MWRITE/MWERASE to complete ... * (d) error handling here seems to be mostly missing. * * Two persistent bits per page, plus a per-sector counter, * could support (a) and (b) ... we might consider using * the second half of sector zero, which is just one block, * to track that state. (On AT91, that sector should also * support boot-from-DataFlash.) */ addr = pageaddr << priv->page_offset; /* (1) Maybe transfer partial page to Buffer1 */ if (writelen != priv->page_size) { command[0] = OP_TRANSFER_BUF1; command[1] = (addr & 0x00FF0000) >> 16; command[2] = (addr & 0x0000FF00) >> 8; command[3] = 0; DEBUG(MTD_DEBUG_LEVEL3, "TRANSFER: (%x) %x %x %x\n", command[0], command[1], command[2], command[3]); status = spi_sync(spi, &msg); if (status < 0) DEBUG(MTD_DEBUG_LEVEL1, "%s: xfer %u -> %d \n", spi->dev.bus_id, addr, status); (void) dataflash_waitready(priv->spi); } /* (2) Program full page via Buffer1 */ addr += offset; command[0] = OP_PROGRAM_VIA_BUF1; command[1] = (addr & 0x00FF0000) >> 16; command[2] = (addr & 0x0000FF00) >> 8; command[3] = (addr & 0x000000FF); DEBUG(MTD_DEBUG_LEVEL3, "PROGRAM: (%x) %x %x %x\n", command[0], command[1], command[2], command[3]); x[1].tx_buf = writebuf; x[1].len = writelen; spi_message_add_tail(x + 1, &msg); status = spi_sync(spi, &msg); spi_transfer_del(x + 1); if (status < 0) DEBUG(MTD_DEBUG_LEVEL1, "%s: pgm %u/%u -> %d \n", spi->dev.bus_id, addr, writelen, status); (void) dataflash_waitready(priv->spi); #ifdef CONFIG_DATAFLASH_WRITE_VERIFY /* (3) Compare to Buffer1 */ addr = pageaddr << priv->page_offset; command[0] = OP_COMPARE_BUF1; command[1] = (addr & 0x00FF0000) >> 16; command[2] = (addr & 0x0000FF00) >> 8; command[3] = 0; DEBUG(MTD_DEBUG_LEVEL3, "COMPARE: (%x) %x %x %x\n", command[0], command[1], command[2], command[3]); status = spi_sync(spi, &msg); if (status < 0) DEBUG(MTD_DEBUG_LEVEL1, "%s: compare %u -> %d \n", spi->dev.bus_id, addr, status); status = dataflash_waitready(priv->spi); /* Check result of the compare operation */ if ((status & (1 << 6)) == 1) { printk(KERN_ERR "%s: compare page %u, err %d\n", spi->dev.bus_id, pageaddr, status); remaining = 0; status = -EIO; break; } else status = 0; #endif /* CONFIG_DATAFLASH_WRITE_VERIFY */ remaining = remaining - writelen; pageaddr++; offset = 0; writebuf += writelen; *retlen += writelen; if (remaining > priv->page_size) writelen = priv->page_size; else writelen = remaining; } up(&priv->lock); return status; } /* ......................................................................... */ /* * Register DataFlash device with MTD subsystem. */ static int __devinit add_dataflash(struct spi_device *spi, char *name, int nr_pages, int pagesize, int pageoffset) { struct dataflash *priv; struct mtd_info *device; struct flash_platform_data *pdata = spi->dev.platform_data; priv = (struct dataflash *) kzalloc(sizeof *priv, GFP_KERNEL); if (!priv) return -ENOMEM; init_MUTEX(&priv->lock); priv->spi = spi; priv->page_size = pagesize; priv->page_offset = pageoffset; /* name must be usable with cmdlinepart */ sprintf(priv->name, "spi%d.%d-%s", spi->master->bus_num, spi->chip_select, name); device = &priv->mtd; device->name = (pdata && pdata->name) ? pdata->name : priv->name; device->size = nr_pages * pagesize; device->erasesize = pagesize; device->owner = THIS_MODULE; device->type = MTD_DATAFLASH; device->flags = MTD_CAP_NORFLASH; device->erase = dataflash_erase; device->read = dataflash_read; device->write = dataflash_write; device->priv = priv; dev_info(&spi->dev, "%s (%d KBytes)\n", name, device->size/1024); dev_set_drvdata(&spi->dev, priv); if (mtd_has_partitions()) { struct mtd_partition *parts; int nr_parts = 0; #ifdef CONFIG_MTD_CMDLINE_PARTS static const char *part_probes[] = { "cmdlinepart", NULL, }; nr_parts = parse_mtd_partitions(device, part_probes, &parts, 0); #endif if (nr_parts <= 0 && pdata && pdata->parts) { parts = pdata->parts; nr_parts = pdata->nr_parts; } if (nr_parts > 0) { priv->partitioned = 1; return add_mtd_partitions(device, parts, nr_parts); } } else if (pdata && pdata->nr_parts) dev_warn(&spi->dev, "ignoring %d default partitions on %s\n", pdata->nr_parts, device->name); return add_mtd_device(device) == 1 ? -ENODEV : 0; } /* * Detect and initialize DataFlash device: * * Device Density ID code #Pages PageSize Offset * AT45DB011B 1Mbit (128K) xx0011xx (0x0c) 512 264 9 * AT45DB021B 2Mbit (256K) xx0101xx (0x14) 1025 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 __devinit dataflash_probe(struct spi_device *spi) { int status; status = dataflash_status(spi); if (status <= 0 || status == 0xff) { DEBUG(MTD_DEBUG_LEVEL1, "%s: status error %d\n", spi->dev.bus_id, status); if (status == 0xff) status = -ENODEV; return status; } /* if there's a device there, assume it's dataflash. * board setup should have set spi->max_speed_max to * match f(car) for continuous reads, mode 0 or 3. */ switch (status & 0x3c) { case 0x0c: /* 0 0 1 1 x x */ status = add_dataflash(spi, "AT45DB011B", 512, 264, 9); break; case 0x14: /* 0 1 0 1 x x */ status = add_dataflash(spi, "AT45DB021B", 1025, 264, 9); break; case 0x1c: /* 0 1 1 1 x x */ status = add_dataflash(spi, "AT45DB041x", 2048, 264, 9); break; case 0x24: /* 1 0 0 1 x x */ status = add_dataflash(spi, "AT45DB081B", 4096, 264, 9); break; case 0x2c: /* 1 0 1 1 x x */ status = add_dataflash(spi, "AT45DB161x", 4096, 528, 10); break; case 0x34: /* 1 1 0 1 x x */ status = add_dataflash(spi, "AT45DB321x", 8192, 528, 10); break; case 0x38: /* 1 1 1 x x x */ case 0x3c: status = add_dataflash(spi, "AT45DB642x", 8192, 1056, 11); break; /* obsolete AT45DB1282 not (yet?) supported */ default: DEBUG(MTD_DEBUG_LEVEL1, "%s: unsupported device (%x)\n", spi->dev.bus_id, status & 0x3c); status = -ENODEV; } if (status < 0) DEBUG(MTD_DEBUG_LEVEL1, "%s: add_dataflash --> %d\n", spi->dev.bus_id, status); return status; } static int __devexit dataflash_remove(struct spi_device *spi) { struct dataflash *flash = dev_get_drvdata(&spi->dev); int status; DEBUG(MTD_DEBUG_LEVEL1, "%s: remove\n", spi->dev.bus_id); if (mtd_has_partitions() && flash->partitioned) status = del_mtd_partitions(&flash->mtd); else status = del_mtd_device(&flash->mtd); if (status == 0) kfree(flash); return status; } static struct spi_driver dataflash_driver = { .driver = { .name = "mtd_dataflash", .bus = &spi_bus_type, .owner = THIS_MODULE, }, .probe = dataflash_probe, .remove = __devexit_p(dataflash_remove), /* FIXME: investigate suspend and resume... */ }; static int __init dataflash_init(void) { return spi_register_driver(&dataflash_driver); } module_init(dataflash_init); static void __exit dataflash_exit(void) { spi_unregister_driver(&dataflash_driver); } module_exit(dataflash_exit); MODULE_LICENSE("GPL"); MODULE_AUTHOR("Andrew Victor, David Brownell"); MODULE_DESCRIPTION("MTD DataFlash driver");