diff options
Diffstat (limited to 'drivers/mtd/devices/mtd_dataflash.c')
| -rw-r--r-- | drivers/mtd/devices/mtd_dataflash.c | 928 |
1 files changed, 928 insertions, 0 deletions
diff --git a/drivers/mtd/devices/mtd_dataflash.c b/drivers/mtd/devices/mtd_dataflash.c new file mode 100644 index 000000000..0099aba72 --- /dev/null +++ b/drivers/mtd/devices/mtd_dataflash.c @@ -0,0 +1,928 @@ +/* + * 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/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/of_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 (yet?) distinguish between MMC and DataFlash + * protocols during enumeration. + */ + +/* 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_REVC 0x9A +#define OP_WRITE_SECURITY 0x9B /* revision D */ + + +struct dataflash { + uint8_t command[4]; + char name[24]; + + unsigned short page_offset; /* offset in flash address */ + unsigned int page_size; /* of bytes per page */ + + struct mutex lock; + struct spi_device *spi; + + struct mtd_info mtd; +}; + +#ifdef CONFIG_OF +static const struct of_device_id dataflash_dt_ids[] = { + { .compatible = "atmel,at45", }, + { .compatible = "atmel,dataflash", }, + { /* sentinel */ } +}; +#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) { + pr_debug("%s: status %d?\n", + dev_name(&spi->dev), 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 = mtd->priv; + struct spi_device *spi = priv->spi; + struct spi_transfer x = { }; + struct spi_message msg; + unsigned blocksize = priv->page_size << 3; + uint8_t *command; + uint32_t rem; + + pr_debug("%s: erase addr=0x%llx len 0x%llx\n", + dev_name(&spi->dev), (long long)instr->addr, + (long long)instr->len); + + div_u64_rem(instr->len, priv->page_size, &rem); + if (rem) + return -EINVAL; + div_u64_rem(instr->addr, priv->page_size, &rem); + if (rem) + return -EINVAL; + + spi_message_init(&msg); + + x.tx_buf = command = priv->command; + x.len = 4; + spi_message_add_tail(&x, &msg); + + mutex_lock(&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 = div_u64(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] = (uint8_t)(pageaddr >> 16); + command[2] = (uint8_t)(pageaddr >> 8); + command[3] = 0; + + pr_debug("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", + dev_name(&spi->dev), 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; + } + } + mutex_unlock(&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 = mtd->priv; + struct spi_transfer x[2] = { }; + struct spi_message msg; + unsigned int addr; + uint8_t *command; + int status; + + pr_debug("%s: read 0x%x..0x%x\n", dev_name(&priv->spi->dev), + (unsigned)from, (unsigned)(from + len)); + + /* Calculate flash page/byte address */ + addr = (((unsigned)from / priv->page_size) << priv->page_offset) + + ((unsigned)from % priv->page_size); + + command = priv->command; + + pr_debug("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); + + mutex_lock(&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] = (uint8_t)(addr >> 16); + command[2] = (uint8_t)(addr >> 8); + command[3] = (uint8_t)(addr >> 0); + /* plus 4 "don't care" bytes */ + + status = spi_sync(priv->spi, &msg); + mutex_unlock(&priv->lock); + + if (status >= 0) { + *retlen = msg.actual_length - 8; + status = 0; + } else + pr_debug("%s: read %x..%x --> %d\n", + dev_name(&priv->spi->dev), + (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 = mtd->priv; + struct spi_device *spi = priv->spi; + struct spi_transfer x[2] = { }; + struct spi_message msg; + unsigned int pageaddr, addr, offset, writelen; + size_t remaining = len; + u_char *writebuf = (u_char *) buf; + int status = -EINVAL; + uint8_t *command; + + pr_debug("%s: write 0x%x..0x%x\n", + dev_name(&spi->dev), (unsigned)to, (unsigned)(to + len)); + + 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; + + mutex_lock(&priv->lock); + while (remaining > 0) { + pr_debug("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; + + pr_debug("TRANSFER: (%x) %x %x %x\n", + command[0], command[1], command[2], command[3]); + + status = spi_sync(spi, &msg); + if (status < 0) + pr_debug("%s: xfer %u -> %d\n", + dev_name(&spi->dev), 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); + + pr_debug("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) + pr_debug("%s: pgm %u/%u -> %d\n", + dev_name(&spi->dev), addr, writelen, status); + + (void) dataflash_waitready(priv->spi); + + +#ifdef CONFIG_MTD_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; + + pr_debug("COMPARE: (%x) %x %x %x\n", + command[0], command[1], command[2], command[3]); + + status = spi_sync(spi, &msg); + if (status < 0) + pr_debug("%s: compare %u -> %d\n", + dev_name(&spi->dev), addr, status); + + status = dataflash_waitready(priv->spi); + + /* Check result of the compare operation */ + if (status & (1 << 6)) { + printk(KERN_ERR "%s: compare page %u, err %d\n", + dev_name(&spi->dev), pageaddr, status); + remaining = 0; + status = -EIO; + break; + } else + status = 0; + +#endif /* CONFIG_MTD_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; + } + mutex_unlock(&priv->lock); + + return status; +} + +/* ......................................................................... */ + +#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) +{ + /* Report both blocks as identical: bytes 0..64, locked. + * Unless the user block changed from all-ones, we can't + * tell whether it's still writable; so we assume it isn't. + */ + info->start = 0; + info->length = 64; + info->locked = 1; + *retlen = sizeof(*info); + return 0; +} + +static ssize_t otp_read(struct spi_device *spi, unsigned base, + uint8_t *buf, loff_t off, size_t len) +{ + struct spi_message m; + size_t l; + uint8_t *scratch; + struct spi_transfer t; + int status; + + if (off > 64) + return -EINVAL; + + if ((off + len) > 64) + len = 64 - off; + + spi_message_init(&m); + + l = 4 + base + off + len; + scratch = kzalloc(l, GFP_KERNEL); + if (!scratch) + return -ENOMEM; + + /* OUT: OP_READ_SECURITY, 3 don't-care bytes, zeroes + * IN: ignore 4 bytes, data bytes 0..N (max 127) + */ + scratch[0] = OP_READ_SECURITY; + + memset(&t, 0, sizeof t); + t.tx_buf = scratch; + t.rx_buf = scratch; + t.len = l; + spi_message_add_tail(&t, &m); + + dataflash_waitready(spi); + + status = spi_sync(spi, &m); + if (status >= 0) { + memcpy(buf, scratch + 4 + base + off, len); + status = len; + } + + kfree(scratch); + return status; +} + +static int dataflash_read_fact_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct dataflash *priv = mtd->priv; + int status; + + /* 64 bytes, from 0..63 ... start at 64 on-chip */ + mutex_lock(&priv->lock); + status = otp_read(priv->spi, 64, buf, from, len); + mutex_unlock(&priv->lock); + + if (status < 0) + return status; + *retlen = status; + return 0; +} + +static int dataflash_read_user_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct dataflash *priv = mtd->priv; + int status; + + /* 64 bytes, from 0..63 ... start at 0 on-chip */ + mutex_lock(&priv->lock); + status = otp_read(priv->spi, 0, buf, from, len); + mutex_unlock(&priv->lock); + + if (status < 0) + return status; + *retlen = status; + return 0; +} + +static int dataflash_write_user_otp(struct mtd_info *mtd, + loff_t from, size_t len, size_t *retlen, u_char *buf) +{ + struct spi_message m; + const size_t l = 4 + 64; + uint8_t *scratch; + struct spi_transfer t; + struct dataflash *priv = mtd->priv; + int status; + + if (from >= 64) { + /* + * Attempting to write beyond the end of OTP memory, + * no data can be written. + */ + *retlen = 0; + return 0; + } + + /* Truncate the write to fit into OTP memory. */ + if ((from + len) > 64) + len = 64 - from; + + /* OUT: OP_WRITE_SECURITY, 3 zeroes, 64 data-or-zero bytes + * IN: ignore all + */ + scratch = kzalloc(l, GFP_KERNEL); + if (!scratch) + return -ENOMEM; + scratch[0] = OP_WRITE_SECURITY; + memcpy(scratch + 4 + from, buf, len); + + spi_message_init(&m); + + memset(&t, 0, sizeof t); + t.tx_buf = scratch; + t.len = l; + spi_message_add_tail(&t, &m); + + /* Write the OTP bits, if they've not yet been written. + * This modifies SRAM buffer1. + */ + mutex_lock(&priv->lock); + dataflash_waitready(priv->spi); + status = spi_sync(priv->spi, &m); + mutex_unlock(&priv->lock); + + kfree(scratch); + + if (status >= 0) { + status = 0; + *retlen = len; + } + return status; +} + +static char *otp_setup(struct mtd_info *device, char revision) +{ + device->_get_fact_prot_info = dataflash_get_otp_info; + device->_read_fact_prot_reg = dataflash_read_fact_otp; + device->_get_user_prot_info = dataflash_get_otp_info; + device->_read_user_prot_reg = dataflash_read_user_otp; + + /* rev c parts (at45db321c and at45db1281 only!) use a + * different write procedure; not (yet?) implemented. + */ + if (revision > 'c') + device->_write_user_prot_reg = dataflash_write_user_otp; + + return ", OTP"; +} + +#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) +{ + struct dataflash *priv; + struct mtd_info *device; + struct mtd_part_parser_data ppdata; + struct flash_platform_data *pdata = dev_get_platdata(&spi->dev); + char *otp_tag = ""; + int err = 0; + + priv = kzalloc(sizeof *priv, GFP_KERNEL); + if (!priv) + return -ENOMEM; + + mutex_init(&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->writesize = pagesize; + device->owner = THIS_MODULE; + device->type = MTD_DATAFLASH; + device->flags = MTD_WRITEABLE; + device->_erase = dataflash_erase; + device->_read = dataflash_read; + device->_write = dataflash_write; + device->priv = priv; + + device->dev.parent = &spi->dev; + + if (revision >= 'c') + otp_tag = otp_setup(device, revision); + + dev_info(&spi->dev, "%s (%lld KBytes) pagesize %d bytes%s\n", + name, (long long)((device->size + 1023) >> 10), + pagesize, otp_tag); + spi_set_drvdata(spi, priv); + + ppdata.of_node = spi->dev.of_node; + err = mtd_device_parse_register(device, NULL, &ppdata, + pdata ? pdata->parts : NULL, + pdata ? pdata->nr_parts : 0); + + if (!err) + return 0; + + kfree(priv); + return err; +} + +static inline int add_dataflash(struct spi_device *spi, char *name, + int nr_pages, int pagesize, int pageoffset) +{ + return add_dataflash_otp(spi, name, nr_pages, pagesize, + pageoffset, 0); +} + +struct flash_info { + char *name; + + /* JEDEC id has a high byte of zero plus three data bytes: + * the manufacturer id, then a two byte device id. + */ + uint32_t jedec_id; + + /* The size listed here is what works with OP_ERASE_PAGE. */ + unsigned nr_pages; + uint16_t pagesize; + uint16_t pageoffset; + + uint16_t flags; +#define SUP_POW2PS 0x0002 /* supports 2^N byte pages */ +#define IS_POW2PS 0x0001 /* uses 2^N byte pages */ +}; + +static struct flash_info dataflash_data[] = { + + /* + * NOTE: chips with SUP_POW2PS (rev D and up) need two entries, + * one with IS_POW2PS and the other without. The entry with the + * non-2^N byte page size can't name exact chip revisions without + * losing backwards compatibility for cmdlinepart. + * + * These newer chips also support 128-byte security registers (with + * 64 bytes one-time-programmable) and software write-protection. + */ + { "AT45DB011B", 0x1f2200, 512, 264, 9, SUP_POW2PS}, + { "at45db011d", 0x1f2200, 512, 256, 8, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB021B", 0x1f2300, 1024, 264, 9, SUP_POW2PS}, + { "at45db021d", 0x1f2300, 1024, 256, 8, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB041x", 0x1f2400, 2048, 264, 9, SUP_POW2PS}, + { "at45db041d", 0x1f2400, 2048, 256, 8, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB081B", 0x1f2500, 4096, 264, 9, SUP_POW2PS}, + { "at45db081d", 0x1f2500, 4096, 256, 8, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB161x", 0x1f2600, 4096, 528, 10, SUP_POW2PS}, + { "at45db161d", 0x1f2600, 4096, 512, 9, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB321x", 0x1f2700, 8192, 528, 10, 0}, /* rev C */ + + { "AT45DB321x", 0x1f2701, 8192, 528, 10, SUP_POW2PS}, + { "at45db321d", 0x1f2701, 8192, 512, 9, SUP_POW2PS | IS_POW2PS}, + + { "AT45DB642x", 0x1f2800, 8192, 1056, 11, SUP_POW2PS}, + { "at45db642d", 0x1f2800, 8192, 1024, 10, SUP_POW2PS | IS_POW2PS}, +}; + +static struct flash_info *jedec_probe(struct spi_device *spi) +{ + int tmp; + uint8_t code = OP_READ_ID; + uint8_t id[3]; + uint32_t jedec; + struct flash_info *info; + int status; + + /* JEDEC also defines an optional "extended device information" + * string for after vendor-specific data, after the three bytes + * we use here. Supporting some chips might require using it. + * + * If the vendor ID isn't Atmel's (0x1f), assume this call failed. + * That's not an error; only rev C and newer chips handle it, and + * only Atmel sells these chips. + */ + tmp = spi_write_then_read(spi, &code, 1, id, 3); + if (tmp < 0) { + pr_debug("%s: error %d reading JEDEC ID\n", + dev_name(&spi->dev), tmp); + return ERR_PTR(tmp); + } + if (id[0] != 0x1f) + return NULL; + + jedec = id[0]; + jedec = jedec << 8; + jedec |= id[1]; + jedec = jedec << 8; + jedec |= id[2]; + + for (tmp = 0, info = dataflash_data; + tmp < ARRAY_SIZE(dataflash_data); + tmp++, info++) { + if (info->jedec_id == jedec) { + pr_debug("%s: OTP, sector protect%s\n", + dev_name(&spi->dev), + (info->flags & SUP_POW2PS) + ? ", binary pagesize" : "" + ); + if (info->flags & SUP_POW2PS) { + status = dataflash_status(spi); + if (status < 0) { + pr_debug("%s: status error %d\n", + dev_name(&spi->dev), status); + return ERR_PTR(status); + } + if (status & 0x1) { + if (info->flags & IS_POW2PS) + return info; + } else { + if (!(info->flags & IS_POW2PS)) + return info; + } + } else + return info; + } + } + + /* + * Treat other chips as errors ... we won't know the right page + * size (it might be binary) even when we can tell which density + * class is involved (legacy chip id scheme). + */ + dev_warn(&spi->dev, "JEDEC id %06x not handled\n", jedec); + return ERR_PTR(-ENODEV); +} + +/* + * 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) +{ + int status; + struct flash_info *info; + + /* + * Try to detect dataflash by JEDEC ID. + * If it succeeds we know we have either a C or D part. + * D will support power of 2 pagesize option. + * Both support the security register, though with different + * write procedures. + */ + info = jedec_probe(spi); + if (IS_ERR(info)) + return PTR_ERR(info); + if (info != NULL) + return add_dataflash_otp(spi, info->name, info->nr_pages, + info->pagesize, info->pageoffset, + (info->flags & SUP_POW2PS) ? 'd' : 'c'); + + /* + * Older chips support only legacy commands, identifing + * capacity using bits in the status byte. + */ + status = dataflash_status(spi); + if (status <= 0 || status == 0xff) { + pr_debug("%s: status error %d\n", + dev_name(&spi->dev), status); + if (status == 0 || 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", 1024, 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: + dev_info(&spi->dev, "unsupported device (%x)\n", + status & 0x3c); + status = -ENODEV; + } + + if (status < 0) + pr_debug("%s: add_dataflash --> %d\n", dev_name(&spi->dev), + status); + + return status; +} + +static int dataflash_remove(struct spi_device *spi) +{ + struct dataflash *flash = spi_get_drvdata(spi); + int status; + + pr_debug("%s: remove\n", dev_name(&spi->dev)); + + status = mtd_device_unregister(&flash->mtd); + if (status == 0) + kfree(flash); + return status; +} + +static struct spi_driver dataflash_driver = { + .driver = { + .name = "mtd_dataflash", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(dataflash_dt_ids), + }, + + .probe = dataflash_probe, + .remove = dataflash_remove, + + /* FIXME: investigate suspend and resume... */ +}; + +module_spi_driver(dataflash_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Andrew Victor, David Brownell"); +MODULE_DESCRIPTION("MTD DataFlash driver"); +MODULE_ALIAS("spi:mtd_dataflash"); |