mx28evk: add NAND support

NAND support is not enabled by default because Eval Kit is not delivered
with NAND chip. To enable NAND support add CONFIG_CMD_NAND to board config.

Signed-off-by: Lauri Hintsala <lauri.hintsala@bluegiga.com>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/board/freescale/mx28evk/iomux.c b/board/freescale/mx28evk/iomux.c
index 396761b..6587c45 100644
--- a/board/freescale/mx28evk/iomux.c
+++ b/board/freescale/mx28evk/iomux.c
@@ -26,6 +26,7 @@
 #include <asm/arch/sys_proto.h>
 
 #define	MUX_CONFIG_SSP0	(MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP)
+#define	MUX_CONFIG_GPMI	(MXS_PAD_3V3 | MXS_PAD_4MA | MXS_PAD_NOPULL)
 #define	MUX_CONFIG_ENET	(MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP)
 #define	MUX_CONFIG_EMI	(MXS_PAD_3V3 | MXS_PAD_12MA | MXS_PAD_NOPULL)
 #define	MUX_CONFIG_SSP2	(MXS_PAD_3V3 | MXS_PAD_4MA | MXS_PAD_PULLUP)
@@ -55,6 +56,26 @@
 	MX28_PAD_PWM3__GPIO_3_28 |
 		(MXS_PAD_12MA | MXS_PAD_3V3 | MXS_PAD_PULLUP),
 
+#ifdef CONFIG_NAND_MXS
+	/* GPMI NAND */
+	MX28_PAD_GPMI_D00__GPMI_D0 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D01__GPMI_D1 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D02__GPMI_D2 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D03__GPMI_D3 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D04__GPMI_D4 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D05__GPMI_D5 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D06__GPMI_D6 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_D07__GPMI_D7 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_CE0N__GPMI_CE0N | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_RDY0__GPMI_READY0 | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_RDN__GPMI_RDN |
+		(MXS_PAD_3V3 | MXS_PAD_8MA | MXS_PAD_PULLUP),
+	MX28_PAD_GPMI_WRN__GPMI_WRN | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_ALE__GPMI_ALE | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_CLE__GPMI_CLE | MUX_CONFIG_GPMI,
+	MX28_PAD_GPMI_RESETN__GPMI_RESETN | MUX_CONFIG_GPMI,
+#endif
+
 	/* FEC0 */
 	MX28_PAD_ENET0_MDC__ENET0_MDC | MUX_CONFIG_ENET,
 	MX28_PAD_ENET0_MDIO__ENET0_MDIO | MUX_CONFIG_ENET,