powerpc/mpc8536ds: Invert SDHC_WP pin polarity

MPC8536 Rev 1.0 silicon have NMG_eSDHC118 erratum, so that the SDHC write
protected pin polarity does not follow the SD card standard in MPC8536
Rev 1.0 silicon.

The MPC8536DS board invert the SDHC_WP pin as a workaround.  However, this
silicon erratum has been fixed in Rev 1.1, So need invert the SDHC_WP
polarity again when use the MPC8536 Rev1.1 and greater on MPC8536DS board.

Signed-off-by: Xie Xiaobo <r63061@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

board/freescale/mpc8536ds/mpc8536ds.c

@@ -51,6 +51,14 @@ int board_early_init_f (void)
 	setbits_be32(&gur->pmuxcr,
 			(MPC85xx_PMUXCR_SDHC_CD |
 			 MPC85xx_PMUXCR_SDHC_WP));
+
+	/* The MPC8536DS board insert the SDHC_WP pin for erratum NMG_eSDHC118,
+	 * however, this erratum only applies to MPC8536 Rev1.0.
+	 * So set SDHC_WP to active-low when use MPC8536 Rev1.1 and greater.*/
+	if ((((SVR_MAJ(get_svr()) & 0x7) == 0x1) &&
+			(SVR_MIN(get_svr()) >= 0x1))
+			|| (SVR_MAJ(get_svr() & 0x7) > 0x1))
+		setbits_be32(&gur->gencfgr, MPC85xx_GENCFGR_SDHC_WP_INV);
 #endif
 	return 0;
 }