commit 3f2bc4d6eb5a4fada842462ba22bb6bbb41d00c7
author Bryan Huntsman <bryanh@codeaurora.org> Tue Aug 16 17:27:22 2011 -0700
committer Bryan Huntsman <bryanh@codeaurora.org> Mon Oct 03 09:57:10 2011 -0700
tree 088e0646c8abcbde263d13ee865ba69032ac86dd
parent f06154cc47399dfdb3950d3e6b71d67ee186f69d

Initial Contribution

msm-2.6.38: tag AU_LINUX_ANDROID_GINGERBREAD.02.03.04.00.142

Signed-off-by: Bryan Huntsman <bryanh@codeaurora.org>

arch/arm/mach-msm/subsystem_notif.c

diff --git a/arch/arm/mach-msm/subsystem_notif.c b/arch/arm/mach-msm/subsystem_notif.c
new file mode 100644
index 0000000..f7db54c
--- /dev/null
+++ b/arch/arm/mach-msm/subsystem_notif.c
@@ -0,0 +1,222 @@
+/* Copyright (c) 2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ *
+ * Subsystem Notifier -- Provides notifications
+ * of subsys events.
+ *
+ * Use subsys_notif_register_notifier to register for notifications
+ * and subsys_notif_queue_notification to send notifications.
+ *
+ */
+
+#include <linux/notifier.h>
+#include <linux/init.h>
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include <linux/workqueue.h>
+#include <linux/stringify.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+
+#include <mach/subsystem_notif.h>
+
+struct subsys_notif_info {
+	char name[50];
+	struct srcu_notifier_head subsys_notif_rcvr_list;
+	struct list_head list;
+};
+
+static LIST_HEAD(subsystem_list);
+static DEFINE_MUTEX(notif_lock);
+static DEFINE_MUTEX(notif_add_lock);
+
+#if defined(SUBSYS_RESTART_DEBUG)
+static void subsys_notif_reg_test_notifier(const char *);
+#endif
+
+static struct subsys_notif_info *_notif_find_subsys(const char *subsys_name)
+{
+	struct subsys_notif_info *subsys;
+
+	mutex_lock(&notif_lock);
+	list_for_each_entry(subsys, &subsystem_list, list)
+		if (!strncmp(subsys->name, subsys_name,
+				ARRAY_SIZE(subsys->name))) {
+			mutex_unlock(&notif_lock);
+			return subsys;
+		}
+	mutex_unlock(&notif_lock);
+
+	return NULL;
+}
+
+void *subsys_notif_register_notifier(
+			const char *subsys_name, struct notifier_block *nb)
+{
+	int ret;
+	struct subsys_notif_info *subsys = _notif_find_subsys(subsys_name);
+
+	if (!subsys) {
+
+		/* Possible first time reference to this subsystem. Add it. */
+		subsys = (struct subsys_notif_info *)
+				subsys_notif_add_subsys(subsys_name);
+
+		if (!subsys)
+			return ERR_PTR(-EINVAL);
+	}
+
+	ret = srcu_notifier_chain_register(
+		&subsys->subsys_notif_rcvr_list, nb);
+
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	return subsys;
+}
+EXPORT_SYMBOL(subsys_notif_register_notifier);
+
+int subsys_notif_unregister_notifier(void *subsys_handle,
+				struct notifier_block *nb)
+{
+	int ret;
+	struct subsys_notif_info *subsys =
+			(struct subsys_notif_info *)subsys_handle;
+
+	if (!subsys)
+		return -EINVAL;
+
+	ret = srcu_notifier_chain_unregister(
+		&subsys->subsys_notif_rcvr_list, nb);
+
+	return ret;
+}
+EXPORT_SYMBOL(subsys_notif_unregister_notifier);
+
+void *subsys_notif_add_subsys(const char *subsys_name)
+{
+	struct subsys_notif_info *subsys = NULL;
+
+	if (!subsys_name)
+		goto done;
+
+	mutex_lock(&notif_add_lock);
+
+	subsys = _notif_find_subsys(subsys_name);
+
+	if (subsys) {
+		mutex_unlock(&notif_add_lock);
+		goto done;
+	}
+
+	subsys = kmalloc(sizeof(struct subsys_notif_info), GFP_KERNEL);
+
+	if (!subsys) {
+		mutex_unlock(&notif_add_lock);
+		return ERR_PTR(-EINVAL);
+	}
+
+	strlcpy(subsys->name, subsys_name, ARRAY_SIZE(subsys->name));
+
+	srcu_init_notifier_head(&subsys->subsys_notif_rcvr_list);
+
+	INIT_LIST_HEAD(&subsys->list);
+
+	mutex_lock(&notif_lock);
+	list_add_tail(&subsys->list, &subsystem_list);
+	mutex_unlock(&notif_lock);
+
+	#if defined(SUBSYS_RESTART_DEBUG)
+	subsys_notif_reg_test_notifier(subsys->name);
+	#endif
+
+	mutex_unlock(&notif_add_lock);
+
+done:
+	return subsys;
+}
+EXPORT_SYMBOL(subsys_notif_add_subsys);
+
+int subsys_notif_queue_notification(void *subsys_handle,
+					enum subsys_notif_type notif_type)
+{
+	int ret = 0;
+	struct subsys_notif_info *subsys =
+		(struct subsys_notif_info *) subsys_handle;
+
+	if (!subsys)
+		return -EINVAL;
+
+	if (notif_type < 0 || notif_type >= SUBSYS_NOTIF_TYPE_COUNT)
+		return -EINVAL;
+
+	ret = srcu_notifier_call_chain(
+		&subsys->subsys_notif_rcvr_list, notif_type,
+		(void *)subsys);
+
+	return ret;
+}
+EXPORT_SYMBOL(subsys_notif_queue_notification);
+
+#if defined(SUBSYS_RESTART_DEBUG)
+static const char *notif_to_string(enum subsys_notif_type notif_type)
+{
+	switch (notif_type) {
+
+	case	SUBSYS_BEFORE_SHUTDOWN:
+		return __stringify(SUBSYS_BEFORE_SHUTDOWN);
+
+	case	SUBSYS_AFTER_SHUTDOWN:
+		return __stringify(SUBSYS_AFTER_SHUTDOWN);
+
+	case	SUBSYS_BEFORE_POWERUP:
+		return __stringify(SUBSYS_BEFORE_POWERUP);
+
+	case	SUBSYS_AFTER_POWERUP:
+		return __stringify(SUBSYS_AFTER_POWERUP);
+
+	default:
+		return "unknown";
+	}
+}
+
+static int subsys_notifier_test_call(struct notifier_block *this,
+				  unsigned long code,
+				  void *data)
+{
+	switch (code) {
+
+	default:
+		printk(KERN_WARNING "%s: Notification %s from subsystem %p\n",
+			__func__, notif_to_string(code), data);
+	break;
+
+	}
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block nb = {
+	.notifier_call = subsys_notifier_test_call,
+};
+
+static void subsys_notif_reg_test_notifier(const char *subsys_name)
+{
+	void *handle = subsys_notif_register_notifier(subsys_name, &nb);
+	printk(KERN_WARNING "%s: Registered test notifier, handle=%p",
+			__func__, handle);
+}
+#endif
+
+MODULE_DESCRIPTION("Subsystem Restart Notifier");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL v2");