summaryrefslogtreecommitdiffstats
path: root/drivers/power/reset/syscon-poweroff.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/power/reset/syscon-poweroff.c')
-rw-r--r--drivers/power/reset/syscon-poweroff.c102
1 files changed, 102 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..ed58bdf41
--- /dev/null
+++ b/drivers/power/reset/syscon-poweroff.c
@@ -0,0 +1,102 @@
+// 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/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)
+{
+ 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) {
+ dev_err(&pdev->dev, "pm_power_off already claimed for %ps",
+ pm_power_off);
+ 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);