summaryrefslogtreecommitdiff
path: root/arch/arm/mach-vexpress/reset.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/mach-vexpress/reset.c')
-rw-r--r--arch/arm/mach-vexpress/reset.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/arch/arm/mach-vexpress/reset.c b/arch/arm/mach-vexpress/reset.c
new file mode 100644
index 0000000..465923a
--- /dev/null
+++ b/arch/arm/mach-vexpress/reset.c
@@ -0,0 +1,141 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#include <linux/jiffies.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/stat.h>
+#include <linux/vexpress.h>
+
+static void vexpress_reset_do(struct device *dev, const char *what)
+{
+ int err = -ENOENT;
+ struct vexpress_config_func *func =
+ vexpress_config_func_get_by_dev(dev);
+
+ if (func) {
+ unsigned long timeout;
+
+ err = vexpress_config_write(func, 0, 0);
+
+ timeout = jiffies + HZ;
+ while (time_before(jiffies, timeout))
+ cpu_relax();
+ }
+
+ dev_emerg(dev, "Unable to %s (%d)\n", what, err);
+}
+
+static struct device *vexpress_power_off_device;
+
+void vexpress_power_off(void)
+{
+ vexpress_reset_do(vexpress_power_off_device, "power off");
+}
+
+static struct device *vexpress_restart_device;
+
+void vexpress_restart(char str, const char *cmd)
+{
+ vexpress_reset_do(vexpress_restart_device, "restart");
+}
+
+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;
+}
+
+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 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_reset_probe(struct platform_device *pdev)
+{
+ enum vexpress_reset_func func;
+ const struct of_device_id *match =
+ of_match_device(vexpress_reset_of_match, &pdev->dev);
+
+ if (match)
+ func = (enum vexpress_reset_func)match->data;
+ else
+ func = pdev->id_entry->driver_data;
+
+ switch (func) {
+ case FUNC_SHUTDOWN:
+ vexpress_power_off_device = &pdev->dev;
+ break;
+ case FUNC_RESET:
+ if (!vexpress_restart_device)
+ vexpress_restart_device = &pdev->dev;
+ device_create_file(&pdev->dev, &dev_attr_active);
+ break;
+ case FUNC_REBOOT:
+ vexpress_restart_device = &pdev->dev;
+ device_create_file(&pdev->dev, &dev_attr_active);
+ break;
+ };
+
+ return 0;
+}
+
+static const struct platform_device_id vexpress_reset_id_table[] = {
+ { .name = "vexpress-reset", .driver_data = FUNC_RESET, },
+ { .name = "vexpress-shutdown", .driver_data = FUNC_SHUTDOWN, },
+ { .name = "vexpress-reboot", .driver_data = FUNC_REBOOT, },
+ {}
+};
+
+static struct platform_driver vexpress_reset_driver = {
+ .probe = vexpress_reset_probe,
+ .driver = {
+ .name = "vexpress-reset",
+ .of_match_table = vexpress_reset_of_match,
+ },
+ .id_table = vexpress_reset_id_table,
+};
+
+static int __init vexpress_reset_init(void)
+{
+ return platform_driver_register(&vexpress_reset_driver);
+}
+device_initcall(vexpress_reset_init);