[PATCH V2 5/6] mtd: bcm47xxnflash: implement reading

Rafał Miłecki
2012-11-12T12:03:44Z

drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h | 1 +
drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c | 106 ++++++++++++++++++++++++
2 files changed, 107 insertions(+), 0 deletions(-)

diff --git a/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h b/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
index cc71400..264aec4 100644
--- a/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
+++ b/drivers/mtd/nand/bcm47xxnflash/bcm47xxnflash.h
@@ -11,6 +11,7 @@ struct bcm47xxnflash {
struct mtd_info mtd;

unsigned curr_command;
+ int curr_page_addr;
int curr_column;

u8 id_data[8];
diff --git a/drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c b/drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c
index 7de190e..e42e182 100644
--- a/drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c
+++ b/drivers/mtd/nand/bcm47xxnflash/ops_bcm4706.c
@@ -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 */
--
1.7.7