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authorMoritz Fischer <moritz.fischer@ettus.com>2015-03-11 17:37:18 -0700
committerSebastian Reichel <sre@kernel.org>2015-04-06 18:49:48 +0200
commit8a577608ba4a3cab1d74025cea382e40544ab9cd (patch)
treec65b31a7883f8268eb1647b7262fe3a40954f7d4 /drivers/power/reset/syscon-poweroff.c
parentbbaeeaaf314aaf5e32e20070378bc14792ae3752 (diff)
downloadlinux-stericsson-8a577608ba4a3cab1d74025cea382e40544ab9cd.tar.gz
power: reset: Add generic SYSCON register mapped poweroff.
Add a generic SYSCON register mapped poweroff mechanism. Signed-off-by: Moritz Fischer <moritz.fischer@ettus.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
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 000000000000..5560b0dbc180
--- /dev/null
+++ b/drivers/power/reset/syscon-poweroff.c
@@ -0,0 +1,102 @@
+/*
+ * Generic Syscon Poweroff Driver
+ *
+ * Copyright (c) 2015, National Instruments Corp.
+ * Author: Moritz Fischer <moritz.fischer@ettus.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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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 mask;
+
+void syscon_poweroff(void)
+{
+ /* Issue the poweroff */
+ regmap_write(map, offset, mask);
+
+ mdelay(1000);
+
+ pr_emerg("Unable to poweroff system\n");
+}
+
+static int syscon_poweroff_probe(struct platform_device *pdev)
+{
+ char symname[KSYM_NAME_LEN];
+
+ 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;
+ }
+
+ if (of_property_read_u32(pdev->dev.of_node, "mask", &mask)) {
+ dev_err(&pdev->dev, "unable to read 'mask'");
+ return -EINVAL;
+ }
+
+ 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);