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From bfea2b9be28b20e076d5df8863c25e966f413fa3 Mon Sep 17 00:00:00 2001
From: Maxime Ripard <maxime.ripard@free-electrons.com>
Date: Fri, 20 Dec 2013 22:41:07 +0100
Subject: [PATCH] reset: Add of_reset_control_get
In some cases, you might need to deassert from reset an hardware block that
doesn't associated to a struct device (CPUs, timers, etc.).
Add a small helper to retrieve the reset controller from the device tree
without the need to pass a struct device.
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
drivers/reset/core.c | 39 ++++++++++++++++++++++++++++++---------
include/linux/reset.h | 4 ++++
2 files changed, 34 insertions(+), 9 deletions(-)
diff --git a/drivers/reset/core.c b/drivers/reset/core.c
index d1b6089..4f3dda7 100644
--- a/drivers/reset/core.c
+++ b/drivers/reset/core.c
@@ -127,15 +127,16 @@ int reset_control_deassert(struct reset_control *rstc)
EXPORT_SYMBOL_GPL(reset_control_deassert);
/**
- * reset_control_get - Lookup and obtain a reference to a reset controller.
- * @dev: device to be reset by the controller
+ * of_reset_control_get - Lookup and obtain a reference to a reset controller.
+ * @node: device to be reset by the controller
* @id: reset line name
*
* Returns a struct reset_control or IS_ERR() condition containing errno.
*
* Use of id names is optional.
*/
-struct reset_control *reset_control_get(struct device *dev, const char *id)
+struct reset_control *of_reset_control_get(struct device_node *node,
+ const char *id)
{
struct reset_control *rstc = ERR_PTR(-EPROBE_DEFER);
struct reset_controller_dev *r, *rcdev;
@@ -144,13 +145,10 @@ struct reset_control *reset_control_get(struct device *dev, const char *id)
int rstc_id;
int ret;
- if (!dev)
- return ERR_PTR(-EINVAL);
-
if (id)
- index = of_property_match_string(dev->of_node,
+ index = of_property_match_string(node,
"reset-names", id);
- ret = of_parse_phandle_with_args(dev->of_node, "resets", "#reset-cells",
+ ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
index, &args);
if (ret)
return ERR_PTR(ret);
@@ -185,12 +183,35 @@ struct reset_control *reset_control_get(struct device *dev, const char *id)
return ERR_PTR(-ENOMEM);
}
- rstc->dev = dev;
rstc->rcdev = rcdev;
rstc->id = rstc_id;
return rstc;
}
+EXPORT_SYMBOL_GPL(of_reset_control_get);
+
+/**
+ * reset_control_get - Lookup and obtain a reference to a reset controller.
+ * @dev: device to be reset by the controller
+ * @id: reset line name
+ *
+ * Returns a struct reset_control or IS_ERR() condition containing errno.
+ *
+ * Use of id names is optional.
+ */
+struct reset_control *reset_control_get(struct device *dev, const char *id)
+{
+ struct reset_control *rstc;
+
+ if (!dev)
+ return ERR_PTR(-EINVAL);
+
+ rstc = of_reset_control_get(dev->of_node, id);
+ if (!IS_ERR(rstc))
+ rstc->dev = dev;
+
+ return rstc;
+}
EXPORT_SYMBOL_GPL(reset_control_get);
/**
diff --git a/include/linux/reset.h b/include/linux/reset.h
index 6082247..a398025 100644
--- a/include/linux/reset.h
+++ b/include/linux/reset.h
@@ -1,6 +1,8 @@
#ifndef _LINUX_RESET_H_
#define _LINUX_RESET_H_
+#include <linux/of.h>
+
struct device;
struct reset_control;
@@ -8,6 +10,8 @@ int reset_control_reset(struct reset_control *rstc);
int reset_control_assert(struct reset_control *rstc);
int reset_control_deassert(struct reset_control *rstc);
+struct reset_control *of_reset_control_get(struct device_node *node,
+ const char *id);
struct reset_control *reset_control_get(struct device *dev, const char *id);
void reset_control_put(struct reset_control *rstc);
struct reset_control *devm_reset_control_get(struct device *dev, const char *id);
--
2.0.3
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