mtd: bcm47xxnflash: implement reading

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
This commit is contained in:
Rafał Miłecki 2012-11-12 13:03:24 +01:00 committed by Artem Bityutskiy
parent 0fbc599155
commit 3c01d4cb75
2 changed files with 107 additions and 0 deletions

View File

@ -11,6 +11,7 @@ struct bcm47xxnflash {
struct mtd_info mtd;
unsigned curr_command;
int curr_page_addr;
int curr_column;
u8 id_data[8];

View File

@ -20,6 +20,8 @@
* shown 164 retries as maxiumum. */
#define NFLASH_READY_RETRIES 1000
#define NFLASH_SECTOR_SIZE 512
/**************************************************
* Various helpers
**************************************************/
@ -47,6 +49,80 @@ static int bcm47xxnflash_ops_bcm4706_ctl_cmd(struct bcma_drv_cc *cc, u32 code)
return 0;
}
static int bcm47xxnflash_ops_bcm4706_poll(struct bcma_drv_cc *cc)
{
int i;
for (i = 0; i < NFLASH_READY_RETRIES; i++) {
if (bcma_cc_read32(cc, BCMA_CC_NFLASH_CTL) & 0x04000000) {
if (bcma_cc_read32(cc, BCMA_CC_NFLASH_CTL) &
BCMA_CC_NFLASH_CTL_ERR) {
pr_err("Error on polling\n");
return -EBUSY;
} else {
return 0;
}
}
}
pr_err("Polling timeout!\n");
return -EBUSY;
}
/**************************************************
* R/W
**************************************************/
static void bcm47xxnflash_ops_bcm4706_read(struct mtd_info *mtd, uint8_t *buf,
int len)
{
struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
u32 ctlcode;
u32 *dest = (u32 *)buf;
int i;
int toread;
BUG_ON(b47n->curr_page_addr & ~nand_chip->pagemask);
/* Don't validate column using nand_chip->page_shift, it may be bigger
* when accessing OOB */
while (len) {
/* We can read maximum of 0x200 bytes at once */
toread = min(len, 0x200);
/* Set page and column */
bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_COL_ADDR,
b47n->curr_column);
bcma_cc_write32(b47n->cc, BCMA_CC_NFLASH_ROW_ADDR,
b47n->curr_page_addr);
/* Prepare to read */
ctlcode = 0x40000000 | 0x00080000 | 0x00040000 | 0x00020000 |
0x00010000;
ctlcode |= NAND_CMD_READSTART << 8;
if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc, ctlcode))
return;
if (bcm47xxnflash_ops_bcm4706_poll(b47n->cc))
return;
/* Eventually read some data :) */
for (i = 0; i < toread; i += 4, dest++) {
ctlcode = 0x40000000 | 0x30000000 | 0x00100000;
if (i == toread - 4) /* Last read goes without that */
ctlcode &= ~0x40000000;
if (bcm47xxnflash_ops_bcm4706_ctl_cmd(b47n->cc,
ctlcode))
return;
*dest = bcma_cc_read32(b47n->cc, BCMA_CC_NFLASH_DATA);
}
b47n->curr_column += toread;
len -= toread;
}
}
/**************************************************
* NAND chip ops
**************************************************/
@ -76,6 +152,8 @@ static void bcm47xxnflash_ops_bcm4706_cmdfunc(struct mtd_info *mtd,
if (column != -1)
b47n->curr_column = column;
if (page_addr != -1)
b47n->curr_page_addr = page_addr;
switch (command) {
case NAND_CMD_RESET:
@ -109,6 +187,12 @@ static void bcm47xxnflash_ops_bcm4706_cmdfunc(struct mtd_info *mtd,
}
break;
case NAND_CMD_READ0:
break;
case NAND_CMD_READOOB:
if (page_addr != -1)
b47n->curr_column += mtd->writesize;
break;
default:
pr_err("Command 0x%X unsupported\n", command);
break;
@ -120,6 +204,7 @@ static u8 bcm47xxnflash_ops_bcm4706_read_byte(struct mtd_info *mtd)
{
struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
u32 tmp = 0;
switch (b47n->curr_command) {
case NAND_CMD_READID:
@ -129,12 +214,31 @@ static u8 bcm47xxnflash_ops_bcm4706_read_byte(struct mtd_info *mtd)
return 0;
}
return b47n->id_data[b47n->curr_column++];
case NAND_CMD_READOOB:
bcm47xxnflash_ops_bcm4706_read(mtd, (u8 *)&tmp, 4);
return tmp & 0xFF;
}
pr_err("Invalid command for byte read: 0x%X\n", b47n->curr_command);
return 0;
}
static void bcm47xxnflash_ops_bcm4706_read_buf(struct mtd_info *mtd,
uint8_t *buf, int len)
{
struct nand_chip *nand_chip = (struct nand_chip *)mtd->priv;
struct bcm47xxnflash *b47n = (struct bcm47xxnflash *)nand_chip->priv;
switch (b47n->curr_command) {
case NAND_CMD_READ0:
case NAND_CMD_READOOB:
bcm47xxnflash_ops_bcm4706_read(mtd, buf, len);
return;
}
pr_err("Invalid command for buf read: 0x%X\n", b47n->curr_command);
}
/**************************************************
* Init
**************************************************/
@ -153,6 +257,8 @@ int bcm47xxnflash_ops_bcm4706_init(struct bcm47xxnflash *b47n)
b47n->nand_chip.select_chip = bcm47xxnflash_ops_bcm4706_select_chip;
b47n->nand_chip.cmdfunc = bcm47xxnflash_ops_bcm4706_cmdfunc;
b47n->nand_chip.read_byte = bcm47xxnflash_ops_bcm4706_read_byte;
b47n->nand_chip.read_buf = bcm47xxnflash_ops_bcm4706_read_buf;
b47n->nand_chip.bbt_options = NAND_BBT_USE_FLASH;
b47n->nand_chip.ecc.mode = NAND_ECC_NONE; /* TODO: implement ECC */
/* Enable NAND flash access */