1 files changed, 149 insertions, 0 deletions
diff --git a/drivers/power/reset/vexpress-poweroff.c b/drivers/power/reset/vexpress-poweroff.c
new file mode 100644
index 000000000..1fdbcbd95
--- /dev/null
+++ b/drivers/power/reset/vexpress-poweroff.c
@@ -0,0 +1,149 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#include <linux/delay.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/stat.h>
+#include <linux/vexpress.h>
+
+static void vexpress_reset_do(struct device *dev, const char *what)
+{
+	int err = -ENOENT;
+	struct regmap *reg = dev_get_drvdata(dev);
+
+	if (reg) {
+		err = regmap_write(reg, 0, 0);
+		if (!err)
+			mdelay(1000);
+	}
+
+	dev_emerg(dev, "Unable to %s (%d)\n", what, err);
+}
+
+static struct device *vexpress_power_off_device;
+static atomic_t vexpress_restart_nb_refcnt = ATOMIC_INIT(0);
+
+static void vexpress_power_off(void)
+{
+	vexpress_reset_do(vexpress_power_off_device, "power off");
+}
+
+static struct device *vexpress_restart_device;
+
+static int vexpress_restart(struct notifier_block *this, unsigned long mode,
+			     void *cmd)
+{
+	vexpress_reset_do(vexpress_restart_device, "restart");
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block vexpress_restart_nb = {
+	.notifier_call = vexpress_restart,
+	.priority = 128,
+};
+
+static ssize_t vexpress_reset_active_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	return sprintf(buf, "%d\n", vexpress_restart_device == dev);
+}
+
+static ssize_t vexpress_reset_active_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	long value;
+	int err = kstrtol(buf, 0, &value);
+
+	if (!err && value)
+		vexpress_restart_device = dev;
+
+	return err ? err : count;
+}
+
+static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, vexpress_reset_active_show,
+		   vexpress_reset_active_store);
+
+
+enum vexpress_reset_func { FUNC_RESET, FUNC_SHUTDOWN, FUNC_REBOOT };
+
+static const struct of_device_id vexpress_reset_of_match[] = {
+	{
+		.compatible = "arm,vexpress-reset",
+		.data = (void *)FUNC_RESET,
+	}, {
+		.compatible = "arm,vexpress-shutdown",
+		.data = (void *)FUNC_SHUTDOWN
+	}, {
+		.compatible = "arm,vexpress-reboot",
+		.data = (void *)FUNC_REBOOT
+	},
+	{}
+};
+
+static int _vexpress_register_restart_handler(struct device *dev)
+{
+	int err;
+
+	vexpress_restart_device = dev;
+	if (atomic_inc_return(&vexpress_restart_nb_refcnt) == 1) {
+		err = register_restart_handler(&vexpress_restart_nb);
+		if (err) {
+			dev_err(dev, "cannot register restart handler (err=%d)\n", err);
+			atomic_dec(&vexpress_restart_nb_refcnt);
+			return err;
+		}
+	}
+	device_create_file(dev, &dev_attr_active);
+
+	return 0;
+}
+
+static int vexpress_reset_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *match =
+			of_match_device(vexpress_reset_of_match, &pdev->dev);
+	struct regmap *regmap;
+	int ret = 0;
+
+	if (!match)
+		return -EINVAL;
+
+	regmap = devm_regmap_init_vexpress_config(&pdev->dev);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+	dev_set_drvdata(&pdev->dev, regmap);
+
+	switch ((enum vexpress_reset_func)match->data) {
+	case FUNC_SHUTDOWN:
+		vexpress_power_off_device = &pdev->dev;
+		pm_power_off = vexpress_power_off;
+		break;
+	case FUNC_RESET:
+		if (!vexpress_restart_device)
+			ret = _vexpress_register_restart_handler(&pdev->dev);
+		break;
+	case FUNC_REBOOT:
+		ret = _vexpress_register_restart_handler(&pdev->dev);
+		break;
+	};
+
+	return ret;
+}
+
+static struct platform_driver vexpress_reset_driver = {
+	.probe = vexpress_reset_probe,
+	.driver = {
+		.name = "vexpress-reset",
+		.of_match_table = vexpress_reset_of_match,
+		.suppress_bind_attrs = true,
+	},
+};
+builtin_platform_driver(vexpress_reset_driver);