k1:hibernation: add platform driver to support hibernation

Change-Id: I163f55e5bdac6c65f38a288a6293bd0a86ae4f5e

drivers/soc/spacemit/pm/Makefile

@@ -1,2 +1,3 @@
 obj-y += platform_pm.o
 obj-y += platform_pm_ops.o
+obj-$(CONFIG_HIBERNATION) += platform_hibernation_pm.o platform_hibernation_pm_ops.o

drivers/soc/spacemit/pm/platform_hibernation_pm.c

@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ * Copyright (c) 2022 Ventana Micro Systems Inc.
+ */
+
+#define pr_fmt(fmt) "suspend: " fmt
+
+#include <linux/ftrace.h>
+#include <linux/suspend.h>
+#include <asm/csr.h>
+#include <asm/sbi.h>
+#include <asm/suspend.h>
+#include <linux/spacemit/platform_pm_ops.h>
+
+static int system_hibernate_begin(pm_message_t stage)
+{
+	return 0;
+}
+
+static void system_hibernate_end(void)
+{
+}
+
+static int system_hibernate_pre_snapshot(void)
+{
+	platform_hibernate_pm_pre_snapshot();
+
+	return 0;
+}
+
+static void system_hibernate_finish(void)
+{
+	platform_hibernate_pm_finish();
+}
+
+static int system_hibernate_prepare(void)
+{
+	return 0;
+}
+
+static int system_hibernate_enter(void)
+{
+	return 0;
+}
+
+static void system_hibernate_leave(void)
+{
+}
+
+static int system_hibernate_pre_restore(void)
+{
+	platform_hibernate_pm_pre_snapshot();
+
+	return 0;
+}
+
+static void system_hibernate_restore_cleanup(void)
+{
+}
+
+static void system_hibernate_recover(void)
+{
+}
+
+static const struct platform_hibernation_ops spacemit_system_hibernation_ops ={
+	.begin = system_hibernate_begin,
+	.end = system_hibernate_end,
+	.pre_snapshot = system_hibernate_pre_snapshot,
+	.finish = system_hibernate_finish,
+	.prepare = system_hibernate_prepare,
+	.enter = system_hibernate_enter,
+	.leave = system_hibernate_leave,
+	.pre_restore = system_hibernate_pre_restore,
+	.restore_cleanup = system_hibernate_restore_cleanup,
+	.recover = system_hibernate_recover,
+};
+
+static int __init spacemit_system_hibernation_init(void)
+{
+	hibernation_set_ops(&spacemit_system_hibernation_ops);
+
+	return 0;
+}
+
+late_initcall(spacemit_system_hibernation_init);

drivers/soc/spacemit/pm/platform_hibernation_pm_ops.c

@@ -0,0 +1,72 @@
+#include <linux/mutex.h>
+#include <linux/module.h>
+#include <linux/suspend.h>
+#include <linux/spacemit/platform_pm_ops.h>
+
+static LIST_HEAD(platform_hibernate_pm_ops_list);
+static DEFINE_MUTEX(platform_hibernate_pm_ops_lock);
+
+void register_platform_hibernate_pm_ops(struct platfrom_pm_ops *ops)
+{
+	mutex_lock(&platform_hibernate_pm_ops_lock);
+	list_add_tail(&ops->node, &platform_hibernate_pm_ops_list);
+	mutex_unlock(&platform_hibernate_pm_ops_lock);
+}
+EXPORT_SYMBOL_GPL(register_platform_hibernate_pm_ops);
+
+void unregister_platform_hibernate_pm_ops(struct platfrom_pm_ops *ops)
+{
+	mutex_lock(&platform_hibernate_pm_ops_lock);
+	list_del(&ops->node);
+	mutex_unlock(&platform_hibernate_pm_ops_lock);
+}
+EXPORT_SYMBOL_GPL(unregister_platform_hibernate_pm_ops);
+
+#ifdef CONFIG_PM_SLEEP
+int platform_hibernate_pm_pre_snapshot(void)
+{
+	int ret;
+	struct platfrom_pm_ops *ops;
+
+	mutex_lock(&platform_hibernate_pm_ops_lock);
+
+	list_for_each_entry_reverse(ops, &platform_hibernate_pm_ops_list, node)
+		if (ops->pre_snapshot) {
+			pm_pr_dbg("Calling %pS\n", ops->pre_snapshot);
+			ret = ops->pre_snapshot();
+			if (ret)
+				goto err_out;
+		}
+
+	mutex_unlock(&platform_hibernate_pm_ops_lock);
+
+	return 0;
+
+ err_out:
+	mutex_unlock(&platform_hibernate_pm_ops_lock);
+	pr_err("PM: Platform late suspend callback %pS failed.\n", ops->pre_snapshot);
+
+	/* we just stall here now !!!!! */
+	while (1);
+
+	return ret;
+
+}
+EXPORT_SYMBOL_GPL(platform_hibernate_pm_pre_snapshot);
+
+void platform_hibernate_pm_finish(void)
+{
+	struct platfrom_pm_ops *ops;
+
+	mutex_lock(&platform_hibernate_pm_ops_lock);
+
+	list_for_each_entry(ops, &platform_hibernate_pm_ops_list, node)
+		if (ops->finish) {
+			pm_pr_dbg("Calling %pS\n", ops->finish);
+			ops->finish();
+		}
+
+	mutex_unlock(&platform_hibernate_pm_ops_lock);
+}
+EXPORT_SYMBOL_GPL(platform_hibernate_pm_finish);
+#endif /* CONFIG_PM_SLEEP */

include/linux/spacemit/platform_pm_ops.h

@@ -7,6 +7,10 @@ struct platfrom_pm_ops {
 	struct list_head node;
 	int (*prepare_late)(void);
 	void (*wake)(void);
+#ifdef CONFIG_HIBERNATION
+	int (*pre_snapshot)(void);
+	void (*finish)(void);
+#endif
 };
 
 extern void register_platform_pm_ops(struct platfrom_pm_ops *ops);
@@ -16,4 +20,11 @@ extern int platform_pm_prepare_late_suspend(void);
 extern void platform_pm_resume_wake(void);
 #endif
 
+#ifdef CONFIG_HIBERNATION
+extern void register_platform_hibernate_pm_ops(struct platfrom_pm_ops *ops);
+extern void unregister_platform_hibernate_pm_ops(struct platfrom_pm_ops *ops);
+extern int platform_hibernate_pm_pre_snapshot(void);
+extern void platform_hibernate_pm_finish(void);
+#endif
+
 #endif