File-copy from v4.4.100

This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Please refer to that tree for all history prior to this point.

Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/arch/powerpc/sysdev/fsl_pmc.c b/arch/powerpc/sysdev/fsl_pmc.c
new file mode 100644
index 0000000..1d6fd7c
--- /dev/null
+++ b/arch/powerpc/sysdev/fsl_pmc.c
@@ -0,0 +1,92 @@
+/*
+ * Suspend/resume support
+ *
+ * Copyright 2009  MontaVista Software, Inc.
+ *
+ * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
+ *
+ * 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; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/suspend.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+
+struct pmc_regs {
+	__be32 devdisr;
+	__be32 devdisr2;
+	__be32 :32;
+	__be32 :32;
+	__be32 pmcsr;
+#define PMCSR_SLP	(1 << 17)
+};
+
+static struct device *pmc_dev;
+static struct pmc_regs __iomem *pmc_regs;
+
+static int pmc_suspend_enter(suspend_state_t state)
+{
+	int ret;
+
+	setbits32(&pmc_regs->pmcsr, PMCSR_SLP);
+	/* At this point, the CPU is asleep. */
+
+	/* Upon resume, wait for SLP bit to be clear. */
+	ret = spin_event_timeout((in_be32(&pmc_regs->pmcsr) & PMCSR_SLP) == 0,
+				 10000, 10) ? 0 : -ETIMEDOUT;
+	if (ret)
+		dev_err(pmc_dev, "tired waiting for SLP bit to clear\n");
+	return ret;
+}
+
+static int pmc_suspend_valid(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_STANDBY)
+		return 0;
+	return 1;
+}
+
+static const struct platform_suspend_ops pmc_suspend_ops = {
+	.valid = pmc_suspend_valid,
+	.enter = pmc_suspend_enter,
+};
+
+static int pmc_probe(struct platform_device *ofdev)
+{
+	pmc_regs = of_iomap(ofdev->dev.of_node, 0);
+	if (!pmc_regs)
+		return -ENOMEM;
+
+	pmc_dev = &ofdev->dev;
+	suspend_set_ops(&pmc_suspend_ops);
+	return 0;
+}
+
+static const struct of_device_id pmc_ids[] = {
+	{ .compatible = "fsl,mpc8548-pmc", },
+	{ .compatible = "fsl,mpc8641d-pmc", },
+	{ },
+};
+
+static struct platform_driver pmc_driver = {
+	.driver = {
+		.name = "fsl-pmc",
+		.of_match_table = pmc_ids,
+	},
+	.probe = pmc_probe,
+};
+
+static int __init pmc_init(void)
+{
+	return platform_driver_register(&pmc_driver);
+}
+device_initcall(pmc_init);