[MTD] [NAND] Support multiple chips in CAFÉ driver

The CAFÉ can handle two chip on separate chipselect lines. Hook up the
undocumented chipselect bits in the driver and probe both.

In the case of OLPC, it's not actually two separate devices -- it's a
single '1GiB' package with two 512MiB dies internally. So clear the
NAND_BBT_PERCHIP flag to treat it as a single chip for BBT purposes, and
make life easier for the firmware.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

drivers/mtd/nand/cafe_nand.c

@@ -47,6 +47,9 @@
 #define CAFE_GLOBAL_IRQ_MASK	0x300c
 #define CAFE_NAND_RESET		0x3034
 
+/* Missing from the datasheet: bit 19 of CTRL1 sets CE0 vs. CE1 */
+#define CTRL1_CHIPSELECT	(1<<19)
+
 struct cafe_priv {
 	struct nand_chip nand;
 	struct pci_dev *pdev;
@@ -194,8 +197,8 @@ static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
 
 	cafe->data_pos = cafe->datalen = 0;
 
-	/* Set command valid bit */
-	ctl1 = 0x80000000 | command;
+	/* Set command valid bit, mask in the chip select bit  */
+	ctl1 = 0x80000000 | command | (cafe->ctl1 & CTRL1_CHIPSELECT);
 
 	/* Set RD or WR bits as appropriate */
 	if (command == NAND_CMD_READID || command == NAND_CMD_STATUS) {
@@ -308,8 +311,16 @@ static void cafe_nand_cmdfunc(struct mtd_info *mtd, unsigned command,
 
 static void cafe_select_chip(struct mtd_info *mtd, int chipnr)
 {
-	//struct cafe_priv *cafe = mtd->priv;
-	//	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
+	struct cafe_priv *cafe = mtd->priv;
+
+	cafe_dev_dbg(&cafe->pdev->dev, "select_chip %d\n", chipnr);
+
+	/* Mask the appropriate bit into the stored value of ctl1
+	   which will be used by cafe_nand_cmdfunc() */
+	if (chipnr)
+		cafe->ctl1 |= CTRL1_CHIPSELECT;
+	else
+		cafe->ctl1 &= ~CTRL1_CHIPSELECT;
 }
 
 static int cafe_nand_interrupt(int irq, void *id)
@@ -453,7 +464,7 @@ static uint8_t cafe_mirror_pattern_512[] = { 0xBC };
 
 static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+		| NAND_BBT_2BIT | NAND_BBT_VERSION,
 	.offs =	14,
 	.len = 4,
 	.veroffs = 18,
@@ -463,7 +474,7 @@ static struct nand_bbt_descr cafe_bbt_main_descr_2048 = {
 
 static struct nand_bbt_descr cafe_bbt_mirror_descr_2048 = {
 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+		| NAND_BBT_2BIT | NAND_BBT_VERSION,
 	.offs =	14,
 	.len = 4,
 	.veroffs = 18,
@@ -479,7 +490,7 @@ static struct nand_ecclayout cafe_oobinfo_512 = {
 
 static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+		| NAND_BBT_2BIT | NAND_BBT_VERSION,
 	.offs =	14,
 	.len = 1,
 	.veroffs = 15,
@@ -489,7 +500,7 @@ static struct nand_bbt_descr cafe_bbt_main_descr_512 = {
 
 static struct nand_bbt_descr cafe_bbt_mirror_descr_512 = {
 	.options = NAND_BBT_LASTBLOCK | NAND_BBT_CREATE | NAND_BBT_WRITE
-		| NAND_BBT_2BIT | NAND_BBT_VERSION | NAND_BBT_PERCHIP,
+		| NAND_BBT_2BIT | NAND_BBT_VERSION,
 	.offs =	14,
 	.len = 1,
 	.veroffs = 15,
@@ -731,7 +742,7 @@ static int __devinit cafe_nand_probe(struct pci_dev *pdev,
 		cafe_readl(cafe, GLOBAL_CTRL), cafe_readl(cafe, GLOBAL_IRQ_MASK));
 
 	/* Scan to find existence of the device */
-	if (nand_scan_ident(mtd, 1)) {
+	if (nand_scan_ident(mtd, 2)) {
 		err = -ENXIO;
 		goto out_irq;
 	}