1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/power/reset/syscon-poweroff.c b/drivers/power/reset/syscon-poweroff.c
new file mode 100644
index 000000000..4d6923b10
--- /dev/null
+++ b/drivers/power/reset/syscon-poweroff.c
@@ -0,0 +1,106 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Generic Syscon Poweroff Driver
+ *
+ * Copyright (c) 2015, National Instruments Corp.
+ * Author: Moritz Fischer <moritz.fischer@ettus.com>
+ */
+
+#include <linux/kallsyms.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/notifier.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+
+static struct regmap *map;
+static u32 offset;
+static u32 value;
+static u32 mask;
+
+static void syscon_poweroff(void)
+{
+	/* Issue the poweroff */
+	regmap_update_bits(map, offset, mask, value);
+
+	mdelay(1000);
+
+	pr_emerg("Unable to poweroff system\n");
+}
+
+static int syscon_poweroff_probe(struct platform_device *pdev)
+{
+	char symname[KSYM_NAME_LEN];
+	int mask_err, value_err;
+
+	map = syscon_regmap_lookup_by_phandle(pdev->dev.of_node, "regmap");
+	if (IS_ERR(map)) {
+		dev_err(&pdev->dev, "unable to get syscon");
+		return PTR_ERR(map);
+	}
+
+	if (of_property_read_u32(pdev->dev.of_node, "offset", &offset)) {
+		dev_err(&pdev->dev, "unable to read 'offset'");
+		return -EINVAL;
+	}
+
+	value_err = of_property_read_u32(pdev->dev.of_node, "value", &value);
+	mask_err = of_property_read_u32(pdev->dev.of_node, "mask", &mask);
+	if (value_err && mask_err) {
+		dev_err(&pdev->dev, "unable to read 'value' and 'mask'");
+		return -EINVAL;
+	}
+
+	if (value_err) {
+		/* support old binding */
+		value = mask;
+		mask = 0xFFFFFFFF;
+	} else if (mask_err) {
+		/* support value without mask*/
+		mask = 0xFFFFFFFF;
+	}
+
+	if (pm_power_off) {
+		lookup_symbol_name((ulong)pm_power_off, symname);
+		dev_err(&pdev->dev,
+		"pm_power_off already claimed %p %s",
+		pm_power_off, symname);
+		return -EBUSY;
+	}
+
+	pm_power_off = syscon_poweroff;
+
+	return 0;
+}
+
+static int syscon_poweroff_remove(struct platform_device *pdev)
+{
+	if (pm_power_off == syscon_poweroff)
+		pm_power_off = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id syscon_poweroff_of_match[] = {
+	{ .compatible = "syscon-poweroff" },
+	{}
+};
+
+static struct platform_driver syscon_poweroff_driver = {
+	.probe = syscon_poweroff_probe,
+	.remove = syscon_poweroff_remove,
+	.driver = {
+		.name = "syscon-poweroff",
+		.of_match_table = syscon_poweroff_of_match,
+	},
+};
+
+static int __init syscon_poweroff_register(void)
+{
+	return platform_driver_register(&syscon_poweroff_driver);
+}
+device_initcall(syscon_poweroff_register);