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/*
* Copyright (c) 2015, Sony Mobile Communications Inc.
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/device.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/slab.h>
#include <linux/soc/qcom/smem_state.h>
static LIST_HEAD(smem_states);
static DEFINE_MUTEX(list_lock);
/**
* struct qcom_smem_state - state context
* @refcount: refcount for the state
* @orphan: boolean indicator that this state has been unregistered
* @list: entry in smem_states list
* @of_node: of_node to use for matching the state in DT
* @priv: implementation private data
* @ops: ops for the state
*/
struct qcom_smem_state {
struct kref refcount;
bool orphan;
struct list_head list;
struct device_node *of_node;
void *priv;
struct qcom_smem_state_ops ops;
};
/**
* qcom_smem_state_update_bits() - update the masked bits in state with value
* @state: state handle acquired by calling qcom_smem_state_get()
* @mask: bit mask for the change
* @value: new value for the masked bits
*
* Returns 0 on success, otherwise negative errno.
*/
int qcom_smem_state_update_bits(struct qcom_smem_state *state,
u32 mask,
u32 value)
{
if (state->orphan)
return -ENXIO;
if (!state->ops.update_bits)
return -ENOTSUPP;
return state->ops.update_bits(state->priv, mask, value);
}
EXPORT_SYMBOL_GPL(qcom_smem_state_update_bits);
static struct qcom_smem_state *of_node_to_state(struct device_node *np)
{
struct qcom_smem_state *state;
mutex_lock(&list_lock);
list_for_each_entry(state, &smem_states, list) {
if (state->of_node == np) {
kref_get(&state->refcount);
goto unlock;
}
}
state = ERR_PTR(-EPROBE_DEFER);
unlock:
mutex_unlock(&list_lock);
return state;
}
/**
* qcom_smem_state_get() - acquire handle to a state
* @dev: client device pointer
* @con_id: name of the state to lookup
* @bit: flags from the state reference, indicating which bit's affected
*
* Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() must be
* called to release the returned state handle.
*/
struct qcom_smem_state *qcom_smem_state_get(struct device *dev,
const char *con_id,
unsigned *bit)
{
struct qcom_smem_state *state;
struct of_phandle_args args;
int index = 0;
int ret;
if (con_id) {
index = of_property_match_string(dev->of_node,
"qcom,state-names",
con_id);
if (index < 0) {
dev_err(dev, "missing qcom,state-names\n");
return ERR_PTR(index);
}
}
ret = of_parse_phandle_with_args(dev->of_node,
"qcom,state",
"#qcom,state-cells",
index,
&args);
if (ret) {
dev_err(dev, "failed to parse qcom,state property\n");
return ERR_PTR(ret);
}
if (args.args_count != 1) {
dev_err(dev, "invalid #qcom,state-cells\n");
return ERR_PTR(-EINVAL);
}
state = of_node_to_state(args.np);
if (IS_ERR(state))
goto put;
*bit = args.args[0];
put:
of_node_put(args.np);
return state;
}
EXPORT_SYMBOL_GPL(qcom_smem_state_get);
static void qcom_smem_state_release(struct kref *ref)
{
struct qcom_smem_state *state = container_of(ref, struct qcom_smem_state, refcount);
list_del(&state->list);
kfree(state);
}
/**
* qcom_smem_state_put() - release state handle
* @state: state handle to be released
*/
void qcom_smem_state_put(struct qcom_smem_state *state)
{
mutex_lock(&list_lock);
kref_put(&state->refcount, qcom_smem_state_release);
mutex_unlock(&list_lock);
}
EXPORT_SYMBOL_GPL(qcom_smem_state_put);
/**
* qcom_smem_state_register() - register a new state
* @of_node: of_node used for matching client lookups
* @ops: implementation ops
* @priv: implementation specific private data
*/
struct qcom_smem_state *qcom_smem_state_register(struct device_node *of_node,
const struct qcom_smem_state_ops *ops,
void *priv)
{
struct qcom_smem_state *state;
state = kzalloc(sizeof(*state), GFP_KERNEL);
if (!state)
return ERR_PTR(-ENOMEM);
kref_init(&state->refcount);
state->of_node = of_node;
state->ops = *ops;
state->priv = priv;
mutex_lock(&list_lock);
list_add(&state->list, &smem_states);
mutex_unlock(&list_lock);
return state;
}
EXPORT_SYMBOL_GPL(qcom_smem_state_register);
/**
* qcom_smem_state_unregister() - unregister a registered state
* @state: state handle to be unregistered
*/
void qcom_smem_state_unregister(struct qcom_smem_state *state)
{
state->orphan = true;
qcom_smem_state_put(state);
}
EXPORT_SYMBOL_GPL(qcom_smem_state_unregister);
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