mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-05 18:14:07 +08:00
e677774f50
The core currently doesn't check that the DT cell size matches what the driver declares, which means that every xlate function needs to duplicate that check. Make sure that of_reset_control_get checks for this to avoid duplication and errors. Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
322 lines
8.0 KiB
C
322 lines
8.0 KiB
C
/*
|
|
* 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 <linux/device.h>
|
|
#include <linux/err.h>
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/of.h>
|
|
#include <linux/reset.h>
|
|
#include <linux/reset-controller.h>
|
|
#include <linux/slab.h>
|
|
|
|
static DEFINE_MUTEX(reset_controller_list_mutex);
|
|
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;
|
|
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 (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;
|
|
}
|
|
|
|
mutex_lock(&reset_controller_list_mutex);
|
|
list_add(&rcdev->list, &reset_controller_list);
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
|
|
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)
|
|
{
|
|
mutex_lock(&reset_controller_list_mutex);
|
|
list_del(&rcdev->list);
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
}
|
|
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 -ENOTSUPP;
|
|
}
|
|
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 -ENOTSUPP;
|
|
}
|
|
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 -ENOTSUPP;
|
|
}
|
|
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.
|
|
* @rstc: reset controller
|
|
*/
|
|
int reset_control_status(struct reset_control *rstc)
|
|
{
|
|
if (rstc->rcdev->ops->status)
|
|
return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
|
|
|
|
return -ENOTSUPP;
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_status);
|
|
|
|
/**
|
|
* of_reset_control_get_by_index - Lookup and obtain a reference to a reset
|
|
* controller by index.
|
|
* @node: device to be reset by the controller
|
|
* @index: index of the reset controller
|
|
*
|
|
* This is to be used to perform a list of resets for a device or power domain
|
|
* in whatever order. Returns a struct reset_control or IS_ERR() condition
|
|
* containing errno.
|
|
*/
|
|
struct reset_control *of_reset_control_get_by_index(struct device_node *node,
|
|
int index)
|
|
{
|
|
struct reset_control *rstc;
|
|
struct reset_controller_dev *r, *rcdev;
|
|
struct of_phandle_args args;
|
|
int rstc_id;
|
|
int ret;
|
|
|
|
ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
|
|
index, &args);
|
|
if (ret)
|
|
return ERR_PTR(ret);
|
|
|
|
mutex_lock(&reset_controller_list_mutex);
|
|
rcdev = NULL;
|
|
list_for_each_entry(r, &reset_controller_list, list) {
|
|
if (args.np == r->of_node) {
|
|
rcdev = r;
|
|
break;
|
|
}
|
|
}
|
|
of_node_put(args.np);
|
|
|
|
if (!rcdev) {
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
return ERR_PTR(-EPROBE_DEFER);
|
|
}
|
|
|
|
if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
return ERR_PTR(-EINVAL);
|
|
}
|
|
|
|
rstc_id = rcdev->of_xlate(rcdev, &args);
|
|
if (rstc_id < 0) {
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
return ERR_PTR(rstc_id);
|
|
}
|
|
|
|
try_module_get(rcdev->owner);
|
|
mutex_unlock(&reset_controller_list_mutex);
|
|
|
|
rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
|
|
if (!rstc) {
|
|
module_put(rcdev->owner);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
rstc->rcdev = rcdev;
|
|
rstc->id = rstc_id;
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_reset_control_get_by_index);
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
int index = 0;
|
|
|
|
if (id) {
|
|
index = of_property_match_string(node,
|
|
"reset-names", id);
|
|
if (index < 0)
|
|
return ERR_PTR(-ENOENT);
|
|
}
|
|
return of_reset_control_get_by_index(node, index);
|
|
}
|
|
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)
|
|
{
|
|
if (!dev)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
return of_reset_control_get(dev->of_node, id);
|
|
}
|
|
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;
|
|
|
|
module_put(rstc->rcdev->owner);
|
|
kfree(rstc);
|
|
}
|
|
EXPORT_SYMBOL_GPL(reset_control_put);
|
|
|
|
static void devm_reset_control_release(struct device *dev, void *res)
|
|
{
|
|
reset_control_put(*(struct reset_control **)res);
|
|
}
|
|
|
|
/**
|
|
* devm_reset_control_get - resource managed reset_control_get()
|
|
* @dev: device to be reset by the controller
|
|
* @id: reset line name
|
|
*
|
|
* Managed reset_control_get(). For reset controllers returned from this
|
|
* function, reset_control_put() is called automatically on driver detach.
|
|
* See reset_control_get() for more information.
|
|
*/
|
|
struct reset_control *devm_reset_control_get(struct device *dev, const char *id)
|
|
{
|
|
struct reset_control **ptr, *rstc;
|
|
|
|
ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
|
|
GFP_KERNEL);
|
|
if (!ptr)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
rstc = reset_control_get(dev, id);
|
|
if (!IS_ERR(rstc)) {
|
|
*ptr = rstc;
|
|
devres_add(dev, ptr);
|
|
} else {
|
|
devres_free(ptr);
|
|
}
|
|
|
|
return rstc;
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_reset_control_get);
|
|
|
|
/**
|
|
* 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 *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);
|