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Commit fc0a5921 authored by Maxime Ripard's avatar Maxime Ripard Committed by Philipp Zabel
Browse files

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: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent 0c5b2b91

drivers/reset/core.c

+30 −9
Original line number Diff line number Diff line
@@ -126,15 +126,16 @@ 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;
@@ -143,13 +144,10 @@ 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);
@@ -184,12 +182,35 @@ 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);



/**

include/linux/reset.h

+4 −0
Original line number Diff line number Diff line 
#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);