[POWERPC] mpc52xx suspend to deep-sleep

Implement deep-sleep on MPC52xx.
SDRAM is put into self-refresh with help of SRAM code
(alternatives would be code in FLASH, I-cache).
Interrupt code must also not be in SDRAM, so put it
in I-cache.
MPC52xx core is static, so contents will remain intact even
with clocks turned off.

Signed-off-by: Domen Puncer <domen.puncer@telargo.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/52xx/efika.c

@@ -184,6 +184,16 @@ static void efika_show_cpuinfo(struct seq_file *m)
 	of_node_put(root);
 }
 
+#ifdef CONFIG_PM
+static void efika_suspend_prepare(void __iomem *mbar)
+{
+	u8 pin = 4;	/* GPIO_WKUP_4 (GPIO_PSC6_0 - IRDA_RX) */
+	u8 level = 1;	/* wakeup on high level */
+	/* IOW. to wake it up, short pins 1 and 3 on IRDA connector */
+	mpc52xx_set_wakeup_gpio(pin, level);
+}
+#endif
+
 static void __init efika_setup_arch(void)
 {
 	rtas_initialize();
@@ -199,6 +209,11 @@ static void __init efika_setup_arch(void)
 
 	efika_pcisetup();
 
+#ifdef CONFIG_PM
+	mpc52xx_suspend.board_suspend_prepare = efika_suspend_prepare;
+	mpc52xx_pm_init();
+#endif
+
 	if (ppc_md.progress)
 		ppc_md.progress("Linux/PPC " UTS_RELEASE " running on Efika ;-)\n", 0x0);
 }