mtd: vf610_nfc: enable ONFI detection

This changes enable ONFI detection. The Read ID command now allows
one address byte which is needed for ONFI detection. To read the
ONFI parameter page, the NAND_CMD_PARAM need to be supported. The
CMD code enables one command and one address byte along with reading
data from flash using R/B#, as specified by ONFI.

Signed-off-by: Stefan Agner <stefan@agner.ch>

1 files changed, 49 insertions, 18 deletions

diff --git a/drivers/mtd/nand/vf610_nfc.c b/drivers/mtd/nand/vf610_nfc.c
index 2c02ff5..5c11ac9 100644
--- a/drivers/mtd/nand/vf610_nfc.c
+++ b/drivers/mtd/nand/vf610_nfc.c
@@ -62,6 +62,7 @@
  * Briefly these are bitmasks of controller cycles.
  */
 #define READ_PAGE_CMD_CODE		0x7EE0
+#define READ_ONFI_PARAM_CMD_CODE	0x4860
 #define PROGRAM_PAGE_CMD_CODE		0x7FC0
 #define ERASE_CMD_CODE			0x4EC0
 #define READ_ID_CMD_CODE		0x4804
@@ -150,6 +151,7 @@ struct vf610_nfc {
 	int                alt_buf;
 #define ALT_BUF_ID   1
 #define ALT_BUF_STAT 2
+#define ALT_BUF_ONFI 3
 	struct clk        *clk;
 };
 
@@ -390,6 +392,16 @@ static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
 		vf610_nfc_ecc_mode(mtd, ECC_HW_MODE);
 		break;
 
+	case NAND_CMD_PARAM:
+		nfc->alt_buf = ALT_BUF_ONFI;
+		vf610_nfc_transfer_size(nfc->regs, 768);
+		vf610_nfc_send_command(nfc->regs, NAND_CMD_PARAM,
+				       READ_ONFI_PARAM_CMD_CODE);
+		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
+				    ROW_ADDR_SHIFT, column);
+		vf610_nfc_ecc_mode(mtd, ECC_BYPASS);
+		break;
+
 	case NAND_CMD_ERASE1:
 		vf610_nfc_transfer_size(nfc->regs, 0);
 		vf610_nfc_send_commands(nfc->regs, command,
@@ -399,8 +411,11 @@ static void vf610_nfc_command(struct mtd_info *mtd, unsigned command,
 
 	case NAND_CMD_READID:
 		nfc->alt_buf = ALT_BUF_ID;
+		nfc->column = 0;
 		vf610_nfc_transfer_size(nfc->regs, 0);
 		vf610_nfc_send_command(nfc->regs, command, READ_ID_CMD_CODE);
+		vf610_nfc_set_field(mtd, NFC_ROW_ADDR, ROW_ADDR_MASK,
+				    ROW_ADDR_SHIFT, column);
 		break;
 
 	case NAND_CMD_STATUS:
@@ -422,17 +437,11 @@ static void vf610_nfc_read_buf(struct mtd_info *mtd, u_char *buf, int len)
 	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
 	uint c = nfc->column;
 
-	switch (nfc->alt_buf) {
-	case ALT_BUF_ID:
-		*buf = vf610_nfc_get_id(mtd, c);
-		break;
-	case ALT_BUF_STAT:
-		*buf = vf610_nfc_get_status(mtd);
-		break;
-	default:
-		vf610_nfc_memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, len);
-		break;
-	}
+	/* Alternate buffers are only supported through read_byte */
+	if (nfc->alt_buf)
+		return;
+
+	vf610_nfc_memcpy(buf, nfc->regs + NFC_MAIN_AREA(0) + c, len);
 
 	nfc->column += len;
 }
@@ -453,8 +462,29 @@ static void vf610_nfc_write_buf(struct mtd_info *mtd, const u_char *buf,
 /* Read byte from NFC buffers */
 static u8 vf610_nfc_read_byte(struct mtd_info *mtd)
 {
+	struct vf610_nfc *nfc = mtd_to_nfc(mtd);
 	u8 tmp;
-	vf610_nfc_read_buf(mtd, &tmp, sizeof(tmp));
+	uint c = nfc->column;
+
+	switch (nfc->alt_buf) {
+	case ALT_BUF_ID:
+		tmp = vf610_nfc_get_id(mtd, c);
+		break;
+	case ALT_BUF_STAT:
+		tmp = vf610_nfc_get_status(mtd);
+		break;
+	case ALT_BUF_ONFI:
+#ifdef __LITTLE_ENDIAN
+		/* Reverse byte since the controller uses big endianness */
+		c = nfc->column ^ 0x3;
+		tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c));
+		break;
+#endif
+	default:
+		tmp = *((u8 *)(nfc->regs + NFC_MAIN_AREA(0) + c));
+		break;
+	}
+	nfc->column++;
 	return tmp;
 }
 
@@ -602,13 +632,11 @@ static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
 	mtd->priv = chip;
 	chip->priv = nfc;
 
-	if (cfg.width == 16) {
+	if (cfg.width == 16)
 		chip->options |= NAND_BUSWIDTH_16;
-		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
-	} else {
-		chip->options &= ~NAND_BUSWIDTH_16;
-		vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
-	}
+
+	/* Use 8-bit mode during initialization */
+	vf610_nfc_clear(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
 
 	/* Disable subpage writes as we do not provide ecc->hwctl */
 	chip->options |= NAND_NO_SUBPAGE_WRITE;
@@ -651,6 +679,9 @@ static int vf610_nfc_nand_init(int devnum, void __iomem *addr)
 		goto error;
 	}
 
+	if (cfg.width == 16)
+		vf610_nfc_set(mtd, NFC_FLASH_CONFIG, CONFIG_16BIT);
+
 	chip->ecc.mode = NAND_ECC_SOFT; /* default */
 
 	/* Single buffer only, max 256 OOB minus ECC status */