reset: add reset controller framework
Add stripped sown version of the reset controller framework from the Linux kernel. Signed-off-by: Lucas Stach <dev@lynxeye.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This commit is contained in:
Lucas Stach
Sascha Hauer
parent
caa31714b5
commit
45b95b50cd
|
|
@ -26,5 +26,6 @@ source "drivers/w1/Kconfig"
|
|||
source "drivers/pinctrl/Kconfig"
|
||||
source "drivers/bus/Kconfig"
|
||||
source "drivers/regulator/Kconfig"
|
||||
source "drivers/reset/Kconfig"
|
||||
|
||||
endmenu
|
||||
|
|
|
|||
|
|
@ -25,3 +25,4 @@ obj-$(CONFIG_W1) += w1/
|
|||
obj-y += pinctrl/
|
||||
obj-y += bus/
|
||||
obj-$(CONFIG_REGULATOR) += regulator/
|
||||
obj-$(CONFIG_RESET_CONTROLLER) += reset/
|
||||
|
|
|
|||
|
|
@ -0,0 +1,13 @@
|
|||
config ARCH_HAS_RESET_CONTROLLER
|
||||
bool
|
||||
|
||||
menuconfig RESET_CONTROLLER
|
||||
bool "Reset Controller Support"
|
||||
default y if ARCH_HAS_RESET_CONTROLLER
|
||||
help
|
||||
Generic Reset Controller support.
|
||||
|
||||
This framework is designed to abstract reset handling of devices
|
||||
via GPIOs or SoC-internal reset controller modules.
|
||||
|
||||
If unsure, say no.
|
||||
|
|
@ -0,0 +1 @@
|
|||
obj-$(CONFIG_RESET_CONTROLLER) += core.o
|
||||
|
|
@ -0,0 +1,236 @@
|
|||
/*
|
||||
* Reset Controller framework
|
||||
*
|
||||
* Copyright 2013 Philipp Zabel, Pengutronix
|
||||
*
|
||||
* This program is free software; you can redistribute it and/or modify
|
||||
* it under the terms of the GNU General Public License as published by
|
||||
* the Free Software Foundation; either version 2 of the License, or
|
||||
* (at your option) any later version.
|
||||
*/
|
||||
#include <common.h>
|
||||
#include <malloc.h>
|
||||
#include <linux/err.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/reset.h>
|
||||
#include <linux/reset-controller.h>
|
||||
|
||||
static LIST_HEAD(reset_controller_list);
|
||||
|
||||
/**
|
||||
* struct reset_control - a reset control
|
||||
* @rcdev: a pointer to the reset controller device
|
||||
* this reset control belongs to
|
||||
* @id: ID of the reset controller in the reset
|
||||
* controller device
|
||||
*/
|
||||
struct reset_control {
|
||||
struct reset_controller_dev *rcdev;
|
||||
struct device_d *dev;
|
||||
unsigned int id;
|
||||
};
|
||||
|
||||
/**
|
||||
* of_reset_simple_xlate - translate reset_spec to the reset line number
|
||||
* @rcdev: a pointer to the reset controller device
|
||||
* @reset_spec: reset line specifier as found in the device tree
|
||||
* @flags: a flags pointer to fill in (optional)
|
||||
*
|
||||
* This simple translation function should be used for reset controllers
|
||||
* with 1:1 mapping, where reset lines can be indexed by number without gaps.
|
||||
*/
|
||||
static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
|
||||
const struct of_phandle_args *reset_spec)
|
||||
{
|
||||
if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells))
|
||||
return -EINVAL;
|
||||
|
||||
if (reset_spec->args[0] >= rcdev->nr_resets)
|
||||
return -EINVAL;
|
||||
|
||||
return reset_spec->args[0];
|
||||
}
|
||||
|
||||
/**
|
||||
* reset_controller_register - register a reset controller device
|
||||
* @rcdev: a pointer to the initialized reset controller device
|
||||
*/
|
||||
int reset_controller_register(struct reset_controller_dev *rcdev)
|
||||
{
|
||||
if (!rcdev->of_xlate) {
|
||||
rcdev->of_reset_n_cells = 1;
|
||||
rcdev->of_xlate = of_reset_simple_xlate;
|
||||
}
|
||||
|
||||
list_add(&rcdev->list, &reset_controller_list);
|
||||
|
||||
return 0;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_controller_register);
|
||||
|
||||
/**
|
||||
* reset_controller_unregister - unregister a reset controller device
|
||||
* @rcdev: a pointer to the reset controller device
|
||||
*/
|
||||
void reset_controller_unregister(struct reset_controller_dev *rcdev)
|
||||
{
|
||||
list_del(&rcdev->list);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_controller_unregister);
|
||||
|
||||
/**
|
||||
* reset_control_reset - reset the controlled device
|
||||
* @rstc: reset controller
|
||||
*/
|
||||
int reset_control_reset(struct reset_control *rstc)
|
||||
{
|
||||
if (rstc->rcdev->ops->reset)
|
||||
return rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
|
||||
|
||||
return -ENOSYS;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_control_reset);
|
||||
|
||||
/**
|
||||
* reset_control_assert - asserts the reset line
|
||||
* @rstc: reset controller
|
||||
*/
|
||||
int reset_control_assert(struct reset_control *rstc)
|
||||
{
|
||||
if (rstc->rcdev->ops->assert)
|
||||
return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
|
||||
|
||||
return -ENOSYS;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_control_assert);
|
||||
|
||||
/**
|
||||
* reset_control_deassert - deasserts the reset line
|
||||
* @rstc: reset controller
|
||||
*/
|
||||
int reset_control_deassert(struct reset_control *rstc)
|
||||
{
|
||||
if (rstc->rcdev->ops->deassert)
|
||||
return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
|
||||
|
||||
return -ENOSYS;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_control_deassert);
|
||||
|
||||
/**
|
||||
* 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 *of_reset_control_get(struct device_node *node,
|
||||
const char *id)
|
||||
{
|
||||
struct reset_control *rstc = ERR_PTR(-ENODEV);
|
||||
struct reset_controller_dev *r, *rcdev;
|
||||
struct of_phandle_args args;
|
||||
int index = 0;
|
||||
int rstc_id;
|
||||
int ret;
|
||||
|
||||
if (id)
|
||||
index = of_property_match_string(node,
|
||||
"reset-names", id);
|
||||
ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
|
||||
index, &args);
|
||||
if (ret)
|
||||
return ERR_PTR(ret);
|
||||
|
||||
rcdev = NULL;
|
||||
list_for_each_entry(r, &reset_controller_list, list) {
|
||||
if (args.np == r->of_node) {
|
||||
rcdev = r;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
if (!rcdev) {
|
||||
return ERR_PTR(-ENODEV);
|
||||
}
|
||||
|
||||
rstc_id = rcdev->of_xlate(rcdev, &args);
|
||||
if (rstc_id < 0)
|
||||
return ERR_PTR(rstc_id);
|
||||
|
||||
rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
|
||||
if (!rstc)
|
||||
return ERR_PTR(-ENOMEM);
|
||||
|
||||
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_d *dev, const char *id)
|
||||
{
|
||||
struct reset_control *rstc;
|
||||
|
||||
if (!dev)
|
||||
return ERR_PTR(-EINVAL);
|
||||
|
||||
rstc = of_reset_control_get(dev->device_node, id);
|
||||
if (!IS_ERR(rstc))
|
||||
rstc->dev = dev;
|
||||
|
||||
return rstc;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_control_get);
|
||||
|
||||
/**
|
||||
* reset_control_put - free the reset controller
|
||||
* @rstc: reset controller
|
||||
*/
|
||||
|
||||
void reset_control_put(struct reset_control *rstc)
|
||||
{
|
||||
if (IS_ERR(rstc))
|
||||
return;
|
||||
|
||||
kfree(rstc);
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(reset_control_put);
|
||||
|
||||
/**
|
||||
* device_reset - find reset controller associated with the device
|
||||
* and perform reset
|
||||
* @dev: device to be reset by the controller
|
||||
*
|
||||
* Convenience wrapper for reset_control_get() and reset_control_reset().
|
||||
* This is useful for the common case of devices with single, dedicated reset
|
||||
* lines.
|
||||
*/
|
||||
int device_reset(struct device_d *dev)
|
||||
{
|
||||
struct reset_control *rstc;
|
||||
int ret;
|
||||
|
||||
rstc = reset_control_get(dev, NULL);
|
||||
if (IS_ERR(rstc))
|
||||
return PTR_ERR(rstc);
|
||||
|
||||
ret = reset_control_reset(rstc);
|
||||
|
||||
reset_control_put(rstc);
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(device_reset);
|
||||
|
|
@ -0,0 +1,50 @@
|
|||
#ifndef _LINUX_RESET_CONTROLLER_H_
|
||||
#define _LINUX_RESET_CONTROLLER_H_
|
||||
|
||||
#include <linux/list.h>
|
||||
|
||||
struct reset_controller_dev;
|
||||
|
||||
/**
|
||||
* struct reset_control_ops
|
||||
*
|
||||
* @reset: for self-deasserting resets, does all necessary
|
||||
* things to reset the device
|
||||
* @assert: manually assert the reset line, if supported
|
||||
* @deassert: manually deassert the reset line, if supported
|
||||
*/
|
||||
struct reset_control_ops {
|
||||
int (*reset)(struct reset_controller_dev *rcdev, unsigned long id);
|
||||
int (*assert)(struct reset_controller_dev *rcdev, unsigned long id);
|
||||
int (*deassert)(struct reset_controller_dev *rcdev, unsigned long id);
|
||||
};
|
||||
|
||||
struct device_node;
|
||||
struct of_phandle_args;
|
||||
|
||||
/**
|
||||
* struct reset_controller_dev - reset controller entity that might
|
||||
* provide multiple reset controls
|
||||
* @ops: a pointer to device specific struct reset_control_ops
|
||||
* @owner: kernel module of the reset controller driver
|
||||
* @list: internal list of reset controller devices
|
||||
* @of_node: corresponding device tree node as phandle target
|
||||
* @of_reset_n_cells: number of cells in reset line specifiers
|
||||
* @of_xlate: translation function to translate from specifier as found in the
|
||||
* device tree to id as given to the reset control ops
|
||||
* @nr_resets: number of reset controls in this reset controller device
|
||||
*/
|
||||
struct reset_controller_dev {
|
||||
struct reset_control_ops *ops;
|
||||
struct list_head list;
|
||||
struct device_node *of_node;
|
||||
int of_reset_n_cells;
|
||||
int (*of_xlate)(struct reset_controller_dev *rcdev,
|
||||
const struct of_phandle_args *reset_spec);
|
||||
unsigned int nr_resets;
|
||||
};
|
||||
|
||||
int reset_controller_register(struct reset_controller_dev *rcdev);
|
||||
void reset_controller_unregister(struct reset_controller_dev *rcdev);
|
||||
|
||||
#endif
|
||||
|
|
@ -0,0 +1,67 @@
|
|||
#ifndef _LINUX_RESET_H_
|
||||
#define _LINUX_RESET_H_
|
||||
|
||||
struct device_d;
|
||||
struct reset_control;
|
||||
|
||||
#ifdef CONFIG_RESET_CONTROLLER
|
||||
|
||||
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 *reset_control_get(struct device_d *dev, const char *id);
|
||||
void reset_control_put(struct reset_control *rstc);
|
||||
|
||||
int __must_check device_reset(struct device_d *dev);
|
||||
|
||||
static inline int device_reset_optional(struct device_d *dev)
|
||||
{
|
||||
return device_reset(dev);
|
||||
}
|
||||
|
||||
static inline struct reset_control *reset_control_get_optional(
|
||||
struct device_d *dev, const char *id)
|
||||
{
|
||||
return reset_control_get(dev, id);
|
||||
}
|
||||
|
||||
#else
|
||||
|
||||
static inline int reset_control_reset(struct reset_control *rstc)
|
||||
{
|
||||
WARN_ON(1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int reset_control_assert(struct reset_control *rstc)
|
||||
{
|
||||
WARN_ON(1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline int reset_control_deassert(struct reset_control *rstc)
|
||||
{
|
||||
WARN_ON(1);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void reset_control_put(struct reset_control *rstc)
|
||||
{
|
||||
WARN_ON(1);
|
||||
}
|
||||
|
||||
static inline int device_reset_optional(struct device_d *dev)
|
||||
{
|
||||
return -ENOSYS;
|
||||
}
|
||||
|
||||
static inline struct reset_control *reset_control_get_optional(
|
||||
struct device_d *dev, const char *id)
|
||||
{
|
||||
return ERR_PTR(-ENOSYS);
|
||||
}
|
||||
|
||||
#endif /* CONFIG_RESET_CONTROLLER */
|
||||
|
||||
#endif
|
||||
Loading…
Reference in New Issue