[POWERPC] pseries: Enabling auto poweron after power is restored.

During power outages, the UPS notifies the system for a shutdown.
In the current setup, it isn't possible to poweron when power is
restored.  This patch fixes the issue by calling the right
ibm,power-off-ups token during such events.  It also adds a sysfs
interface so userspace can specify whether or not to power on when
power is restored.

Signed-off-by: Manish Ahuja <ahuja@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/platforms/pseries/Makefile

@@ -4,7 +4,7 @@ endif
 
 obj-y			:= pci.o lpar.o hvCall.o nvram.o reconfig.o \
 			   setup.o iommu.o ras.o rtasd.o pci_dlpar.o \
-			   firmware.o
+			   firmware.o power.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_XICS)	+= xics.o
 obj-$(CONFIG_SCANLOG)	+= scanlog.o

arch/powerpc/platforms/pseries/power.c

@@ -0,0 +1,87 @@
+/*
+ *  Interface for power-management for ppc64 compliant platform
+ *
+ *  Manish Ahuja <mahuja@us.ibm.com>
+ *
+ *  Feb 2007
+ *
+ *  Copyright (C) 2007 IBM Corporation.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; version 2 of the License.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kobject.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+
+unsigned long rtas_poweron_auto; /* default and normal state is 0 */
+
+static ssize_t auto_poweron_show(struct subsystem *subsys, char *buf)
+{
+        return sprintf(buf, "%lu\n", rtas_poweron_auto);
+}
+
+static ssize_t
+auto_poweron_store(struct subsystem *subsys, const char *buf, size_t n)
+{
+	int ret;
+	unsigned long ups_restart;
+	ret = sscanf(buf, "%lu", &ups_restart);
+
+	if ((ret == 1) && ((ups_restart == 1) || (ups_restart == 0))){
+		rtas_poweron_auto = ups_restart;
+		return n;
+	}
+	return -EINVAL;
+}
+
+static struct subsys_attribute auto_poweron_attr = {
+        .attr   = {
+                .name = __stringify(auto_poweron),
+                .mode = 0644,
+        },
+        .show   = auto_poweron_show,
+        .store  = auto_poweron_store,
+};
+
+#ifndef CONFIG_PM
+decl_subsys(power,NULL,NULL);
+
+static struct attribute *g[] = {
+        &auto_poweron_attr.attr,
+        NULL,
+};
+
+static struct attribute_group attr_group = {
+        .attrs = g,
+};
+
+static int __init pm_init(void)
+{
+        int error = subsystem_register(&power_subsys);
+        if (!error)
+                error = sysfs_create_group(&power_subsys.kset.kobj,&attr_group);
+        return error;
+}
+core_initcall(pm_init);
+#else
+extern struct subsystem power_subsys;
+
+static int __init apo_pm_init(void)
+{
+	return (subsys_create_file(&power_subsys, &auto_poweron_attr));
+}
+__initcall(apo_pm_init);
+#endif

arch/powerpc/platforms/pseries/pseries.h

@@ -33,4 +33,7 @@ static inline void setup_kexec_cpu_down_xics(void) { }
 static inline void setup_kexec_cpu_down_mpic(void) { }
 #endif
 
+/* Poweron flag used for enabling auto ups restart */
+extern unsigned long rtas_poweron_auto;
+
 #endif /* _PSERIES_PSERIES_H */

arch/powerpc/platforms/pseries/setup.c

@@ -486,6 +486,34 @@ static int pSeries_pci_probe_mode(struct pci_bus *bus)
 	return PCI_PROBE_NORMAL;
 }
 
+/**
+ * pSeries_power_off - tell firmware about how to power off the system.
+ *
+ * This function calls either the power-off rtas token in normal cases
+ * or the ibm,power-off-ups token (if present & requested) in case of
+ * a power failure. If power-off token is used, power on will only be
+ * possible with power button press. If ibm,power-off-ups token is used
+ * it will allow auto poweron after power is restored.
+ */
+void pSeries_power_off(void)
+{
+	int rc;
+	int rtas_poweroff_ups_token = rtas_token("ibm,power-off-ups");
+
+	if (rtas_flash_term_hook)
+		rtas_flash_term_hook(SYS_POWER_OFF);
+
+	if (rtas_poweron_auto == 0 ||
+		rtas_poweroff_ups_token == RTAS_UNKNOWN_SERVICE) {
+		rc = rtas_call(rtas_token("power-off"), 2, 1, NULL, -1, -1);
+		printk(KERN_INFO "RTAS power-off returned %d\n", rc);
+	} else {
+		rc = rtas_call(rtas_poweroff_ups_token, 0, 1, NULL);
+		printk(KERN_INFO "RTAS ibm,power-off-ups returned %d\n", rc);
+	}
+	for (;;);
+}
+
 define_machine(pseries) {
 	.name			= "pSeries",
 	.probe			= pSeries_probe,
@@ -496,7 +524,7 @@ define_machine(pseries) {
 	.pcibios_fixup		= pSeries_final_fixup,
 	.pci_probe_mode		= pSeries_pci_probe_mode,
 	.restart		= rtas_restart,
-	.power_off		= rtas_power_off,
+	.power_off		= pSeries_power_off,
 	.halt			= rtas_halt,
 	.panic			= rtas_os_term,
 	.get_boot_time		= rtas_get_boot_time,