/*
* 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);
memset(&x[0], 0, sizeof(struct spi_transfer) * 2);
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;
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;
}
/*
* 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 = { .tx_dma = 0, };
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] = { { .tx_dma = 0, }, };
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;
}
/*
* 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);
memset(&x, 0, sizeof(x));
x.tx_buf = command = priv->command;
x.len = 4;
spi_message_add_tail(&x, &msg);
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;
}
}
/* Inform MTD subsystem that erase is complete */
instr->state = MTD_ERASE_DONE;
mtd_erase_callback(instr);
return 0;
}
