diff options
| -rw-r--r-- | drivers/mtd/devices/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/mtd/devices/Makefile | 1 | ||||
| -rw-r--r-- | drivers/mtd/devices/mtd_dataflash.c | 623 | ||||
| -rw-r--r-- | include/linux/spi/flash.h | 27 |
4 files changed, 659 insertions, 0 deletions
diff --git a/drivers/mtd/devices/Kconfig b/drivers/mtd/devices/Kconfig index 9a2aa4033c6..84f2eb1fae0 100644 --- a/drivers/mtd/devices/Kconfig +++ b/drivers/mtd/devices/Kconfig @@ -47,6 +47,14 @@ config MTD_MS02NV accelerator. Say Y here if you have a DECstation 5000/2x0 or a DECsystem 5900 equipped with such a module. +config MTD_DATAFLASH + tristate "Support for AT45xxx DataFlash" + depends on MTD && SPI_MASTER && EXPERIMENTAL + help + This enables access to AT45xxx DataFlash chips, using SPI. + Sometimes DataFlash chips are packaged inside MMC-format + cards; at this writing, the MMC stack won't handle those. + config MTD_SLRAM tristate "Uncached system RAM" depends on MTD diff --git a/drivers/mtd/devices/Makefile b/drivers/mtd/devices/Makefile index e38db348057..cd8d8074b5b 100644 --- a/drivers/mtd/devices/Makefile +++ b/drivers/mtd/devices/Makefile @@ -23,3 +23,4 @@ obj-$(CONFIG_MTD_MTDRAM) += mtdram.o obj-$(CONFIG_MTD_LART) += lart.o obj-$(CONFIG_MTD_BLKMTD) += blkmtd.o obj-$(CONFIG_MTD_BLOCK2MTD) += block2mtd.o +obj-$(CONFIG_MTD_DATAFLASH) += mtd_dataflash.o diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c new file mode 100644 index 00000000000..a39b3b6b266 --- /dev/null +++ b/drivers/mtd/devices/mtd_dataflash.c @@ -0,0 +1,623 @@ +/* + * 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 <linux/config.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/delay.h> +#include <linux/device.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 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[1] = { { .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; + + x[0].tx_buf = command = priv->command; + x[0].len = 4; + msg.transfers = x; + msg.n_transfer = 1; + + 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]); + + x[0].tx_buf = command; + x[0].len = 8; + x[1].rx_buf = buf; + x[1].len = len; + msg.transfers = x; + msg.n_transfer = 2; + + 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; + + x[0].tx_buf = command = priv->command; + x[0].len = 4; + msg.transfers = x; + + 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]); + + msg.n_transfer = 1; + 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; + msg.n_transfer = 2; + status = spi_sync(spi, &msg); + 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]); + + msg.n_transfer = 1; + 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->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"); diff --git a/include/linux/spi/flash.h b/include/linux/spi/flash.h new file mode 100644 index 00000000000..2ce6558bf3f --- /dev/null +++ b/include/linux/spi/flash.h @@ -0,0 +1,27 @@ +#ifndef LINUX_SPI_FLASH_H +#define LINUX_SPI_FLASH_H + +struct mtd_partition; + +/** + * struct flash_platform_data: board-specific flash data + * @name: optional flash device name (eg, as used with mtdparts=) + * @parts: optional array of mtd_partitions for static partitioning + * @nr_parts: number of mtd_partitions for static partitoning + * + * Board init code (in arch/.../mach-xxx/board-yyy.c files) can + * provide information about SPI flash parts (such as DataFlash) to + * help set up the device and its appropriate default partitioning. + * + * Note that for DataFlash, sizes for pages, blocks, and sectors are + * rarely powers of two; and partitions should be sector-aligned. + */ +struct flash_platform_data { + char *name; + struct mtd_partition *parts; + unsigned int nr_parts; + + /* we'll likely add more ... use JEDEC IDs, etc */ +}; + +#endif |