[U-Boot] [PATCH v3] This patch fix the usage of the "CE don't care"-type NAND chips

Michael Trimarchi trimarchi at gandalf.sssup.it
Tue Mar 15 08:16:38 CET 2011


atmel_nand: don't require CONFIG_SYS_NAND_ENABLE_PIN
If NCE is hooked up to NCS3, we don't need to (and can't)
explicitly set the state of the NCE pin. Instead, the
controller asserts it automatically as part of a
command/data access. Only "CE don't care"-type NAND chips
can be used in this manner.

Signed-off-by: Michael Trimarchi <michael at amarulasolutions.com>
Cc: Scott Wood <scottwood at freescale.com>
Cc: Reinhard Meyer <u-boot at emk-elektronik.de>

---
Change since V1
	- add a better description
Change since V2:
	- change commit message

diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index ab8bbb3..818d362 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -249,8 +249,10 @@ static void at91_nand_hwcontrol(struct mtd_info *mtd,
 		if (ctrl & NAND_ALE)
 			IO_ADDR_W |= CONFIG_SYS_NAND_MASK_ALE;
 
+#ifdef CONFIG_SYS_NAND_ENABLE_PIN
 		at91_set_gpio_value(CONFIG_SYS_NAND_ENABLE_PIN,
 				    !(ctrl & NAND_NCE));
+#endif
 		this->IO_ADDR_W = (void *) IO_ADDR_W;
 	}
 


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