linux/drivers/soc/qcom/smem_state.c
Thomas Gleixner 97fb5e8d9b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284
Based on 1 normalized pattern(s):

  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

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 294 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141900.825281744@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-05 17:36:37 +02:00

194 lines
4.5 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2015, Sony Mobile Communications Inc.
* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
*/
#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,smem-state-names",
con_id);
if (index < 0) {
dev_err(dev, "missing qcom,smem-state-names\n");
return ERR_PTR(index);
}
}
ret = of_parse_phandle_with_args(dev->of_node,
"qcom,smem-states",
"#qcom,smem-state-cells",
index,
&args);
if (ret) {
dev_err(dev, "failed to parse qcom,smem-states property\n");
return ERR_PTR(ret);
}
if (args.args_count != 1) {
dev_err(dev, "invalid #qcom,smem-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);