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Diffstat (limited to 'drivers/reset/core.c')
-rw-r--r--drivers/reset/core.c57
1 files changed, 43 insertions, 14 deletions
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index 10368ed8fd13..f1e5e65388bb 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -41,7 +41,7 @@ struct reset_control {
struct list_head list;
unsigned int id;
unsigned int refcnt;
- int shared;
+ bool shared;
atomic_t deassert_count;
atomic_t triggered_count;
};
@@ -143,12 +143,18 @@ EXPORT_SYMBOL_GPL(devm_reset_controller_register);
* a no-op.
* Consumers must not use reset_control_(de)assert on shared reset lines when
* reset_control_reset has been used.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
*/
int reset_control_reset(struct reset_control *rstc)
{
int ret;
- if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
return -EINVAL;
if (!rstc->rcdev->ops->reset)
@@ -163,7 +169,7 @@ int reset_control_reset(struct reset_control *rstc)
}
ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
- if (rstc->shared && !ret)
+ if (rstc->shared && ret)
atomic_dec(&rstc->triggered_count);
return ret;
@@ -182,10 +188,17 @@ EXPORT_SYMBOL_GPL(reset_control_reset);
* internal state to be reset, but must be prepared for this to happen.
* Consumers must not use reset_control_reset on shared reset lines when
* reset_control_(de)assert has been used.
+ * return 0.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
*/
int reset_control_assert(struct reset_control *rstc)
{
- if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
return -EINVAL;
if (!rstc->rcdev->ops->assert)
@@ -213,10 +226,17 @@ EXPORT_SYMBOL_GPL(reset_control_assert);
* After calling this function, the reset is guaranteed to be deasserted.
* Consumers must not use reset_control_reset on shared reset lines when
* reset_control_(de)assert has been used.
+ * return 0.
+ *
+ * If rstc is NULL it is an optional reset and the function will just
+ * return 0.
*/
int reset_control_deassert(struct reset_control *rstc)
{
- if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
return -EINVAL;
if (!rstc->rcdev->ops->deassert)
@@ -237,12 +257,15 @@ EXPORT_SYMBOL_GPL(reset_control_deassert);
/**
* reset_control_status - returns a negative errno if not supported, a
* positive value if the reset line is asserted, or zero if the reset
- * line is not asserted.
+ * line is not asserted or if the desc is NULL (optional reset).
* @rstc: reset controller
*/
int reset_control_status(struct reset_control *rstc)
{
- if (WARN_ON(IS_ERR_OR_NULL(rstc)))
+ if (!rstc)
+ return 0;
+
+ if (WARN_ON(IS_ERR(rstc)))
return -EINVAL;
if (rstc->rcdev->ops->status)
@@ -254,7 +277,7 @@ EXPORT_SYMBOL_GPL(reset_control_status);
static struct reset_control *__reset_control_get(
struct reset_controller_dev *rcdev,
- unsigned int index, int shared)
+ unsigned int index, bool shared)
{
struct reset_control *rstc;
@@ -299,7 +322,8 @@ static void __reset_control_put(struct reset_control *rstc)
}
struct reset_control *__of_reset_control_get(struct device_node *node,
- const char *id, int index, int shared)
+ const char *id, int index, bool shared,
+ bool optional)
{
struct reset_control *rstc;
struct reset_controller_dev *r, *rcdev;
@@ -313,14 +337,18 @@ struct reset_control *__of_reset_control_get(struct device_node *node,
if (id) {
index = of_property_match_string(node,
"reset-names", id);
+ if (index == -EILSEQ)
+ return ERR_PTR(index);
if (index < 0)
- return ERR_PTR(-ENOENT);
+ return optional ? NULL : ERR_PTR(-ENOENT);
}
ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
index, &args);
- if (ret)
+ if (ret == -EINVAL)
return ERR_PTR(ret);
+ if (ret)
+ return optional ? NULL : ERR_PTR(ret);
mutex_lock(&reset_list_mutex);
rcdev = NULL;
@@ -364,7 +392,7 @@ EXPORT_SYMBOL_GPL(__of_reset_control_get);
void reset_control_put(struct reset_control *rstc)
{
- if (IS_ERR(rstc))
+ if (IS_ERR_OR_NULL(rstc))
return;
mutex_lock(&reset_list_mutex);
@@ -379,7 +407,8 @@ static void devm_reset_control_release(struct device *dev, void *res)
}
struct reset_control *__devm_reset_control_get(struct device *dev,
- const char *id, int index, int shared)
+ const char *id, int index, bool shared,
+ bool optional)
{
struct reset_control **ptr, *rstc;
@@ -389,7 +418,7 @@ struct reset_control *__devm_reset_control_get(struct device *dev,
return ERR_PTR(-ENOMEM);
rstc = __of_reset_control_get(dev ? dev->of_node : NULL,
- id, index, shared);
+ id, index, shared, optional);
if (!IS_ERR(rstc)) {
*ptr = rstc;
devres_add(dev, ptr);