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path: root/drivers/regulator
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Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/core.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 8588a2490e0a..01f7702a805d 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -28,6 +28,7 @@
static DEFINE_MUTEX(regulator_list_mutex);
static LIST_HEAD(regulator_list);
static LIST_HEAD(regulator_map_list);
+static int has_full_constraints;
/*
* struct regulator_map
@@ -2143,6 +2144,23 @@ out:
EXPORT_SYMBOL_GPL(regulator_suspend_prepare);
/**
+ * regulator_has_full_constraints - the system has fully specified constraints
+ *
+ * Calling this function will cause the regulator API to disable all
+ * regulators which have a zero use count and don't have an always_on
+ * constraint in a late_initcall.
+ *
+ * The intention is that this will become the default behaviour in a
+ * future kernel release so users are encouraged to use this facility
+ * now.
+ */
+void regulator_has_full_constraints(void)
+{
+ has_full_constraints = 1;
+}
+EXPORT_SYMBOL_GPL(regulator_has_full_constraints);
+
+/**
* rdev_get_drvdata - get rdev regulator driver data
* @rdev: regulator
*
@@ -2209,3 +2227,77 @@ static int __init regulator_init(void)
/* init early to allow our consumers to complete system booting */
core_initcall(regulator_init);
+
+static int __init regulator_init_complete(void)
+{
+ struct regulator_dev *rdev;
+ struct regulator_ops *ops;
+ struct regulation_constraints *c;
+ int enabled, ret;
+ const char *name;
+
+ mutex_lock(&regulator_list_mutex);
+
+ /* If we have a full configuration then disable any regulators
+ * which are not in use or always_on. This will become the
+ * default behaviour in the future.
+ */
+ list_for_each_entry(rdev, &regulator_list, list) {
+ ops = rdev->desc->ops;
+ c = rdev->constraints;
+
+ if (c->name)
+ name = c->name;
+ else if (rdev->desc->name)
+ name = rdev->desc->name;
+ else
+ name = "regulator";
+
+ if (!ops->disable || c->always_on)
+ continue;
+
+ mutex_lock(&rdev->mutex);
+
+ if (rdev->use_count)
+ goto unlock;
+
+ /* If we can't read the status assume it's on. */
+ if (ops->is_enabled)
+ enabled = ops->is_enabled(rdev);
+ else
+ enabled = 1;
+
+ if (!enabled)
+ goto unlock;
+
+ if (has_full_constraints) {
+ /* We log since this may kill the system if it
+ * goes wrong. */
+ printk(KERN_INFO "%s: disabling %s\n",
+ __func__, name);
+ ret = ops->disable(rdev);
+ if (ret != 0) {
+ printk(KERN_ERR
+ "%s: couldn't disable %s: %d\n",
+ __func__, name, ret);
+ }
+ } else {
+ /* The intention is that in future we will
+ * assume that full constraints are provided
+ * so warn even if we aren't going to do
+ * anything here.
+ */
+ printk(KERN_WARNING
+ "%s: incomplete constraints, leaving %s on\n",
+ __func__, name);
+ }
+
+unlock:
+ mutex_unlock(&rdev->mutex);
+ }
+
+ mutex_unlock(&regulator_list_mutex);
+
+ return 0;
+}
+late_initcall(regulator_init_complete);