1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2015, Sony Mobile Communications Inc.
4 * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
6 #include <linux/device.h>
7 #include <linux/list.h>
8 #include <linux/module.h>
10 #include <linux/slab.h>
11 #include <linux/soc/qcom/smem_state.h>
13 static LIST_HEAD(smem_states);
14 static DEFINE_MUTEX(list_lock);
17 * struct qcom_smem_state - state context
18 * @refcount: refcount for the state
19 * @orphan: boolean indicator that this state has been unregistered
20 * @list: entry in smem_states list
21 * @of_node: of_node to use for matching the state in DT
22 * @priv: implementation private data
23 * @ops: ops for the state
25 struct qcom_smem_state {
29 struct list_head list;
30 struct device_node *of_node;
34 struct qcom_smem_state_ops ops;
38 * qcom_smem_state_update_bits() - update the masked bits in state with value
39 * @state: state handle acquired by calling qcom_smem_state_get()
40 * @mask: bit mask for the change
41 * @value: new value for the masked bits
43 * Returns 0 on success, otherwise negative errno.
45 int qcom_smem_state_update_bits(struct qcom_smem_state *state,
52 if (!state->ops.update_bits)
55 return state->ops.update_bits(state->priv, mask, value);
57 EXPORT_SYMBOL_GPL(qcom_smem_state_update_bits);
59 static struct qcom_smem_state *of_node_to_state(struct device_node *np)
61 struct qcom_smem_state *state;
63 mutex_lock(&list_lock);
65 list_for_each_entry(state, &smem_states, list) {
66 if (state->of_node == np) {
67 kref_get(&state->refcount);
71 state = ERR_PTR(-EPROBE_DEFER);
74 mutex_unlock(&list_lock);
80 * qcom_smem_state_get() - acquire handle to a state
81 * @dev: client device pointer
82 * @con_id: name of the state to lookup
83 * @bit: flags from the state reference, indicating which bit's affected
85 * Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() must be
86 * called to release the returned state handle.
88 struct qcom_smem_state *qcom_smem_state_get(struct device *dev,
92 struct qcom_smem_state *state;
93 struct of_phandle_args args;
98 index = of_property_match_string(dev->of_node,
99 "qcom,smem-state-names",
102 dev_err(dev, "missing qcom,smem-state-names\n");
103 return ERR_PTR(index);
107 ret = of_parse_phandle_with_args(dev->of_node,
109 "#qcom,smem-state-cells",
113 dev_err(dev, "failed to parse qcom,smem-states property\n");
117 if (args.args_count != 1) {
118 dev_err(dev, "invalid #qcom,smem-state-cells\n");
119 return ERR_PTR(-EINVAL);
122 state = of_node_to_state(args.np);
129 of_node_put(args.np);
132 EXPORT_SYMBOL_GPL(qcom_smem_state_get);
134 static void qcom_smem_state_release(struct kref *ref)
136 struct qcom_smem_state *state = container_of(ref, struct qcom_smem_state, refcount);
138 list_del(&state->list);
143 * qcom_smem_state_put() - release state handle
144 * @state: state handle to be released
146 void qcom_smem_state_put(struct qcom_smem_state *state)
148 mutex_lock(&list_lock);
149 kref_put(&state->refcount, qcom_smem_state_release);
150 mutex_unlock(&list_lock);
152 EXPORT_SYMBOL_GPL(qcom_smem_state_put);
154 static void devm_qcom_smem_state_release(struct device *dev, void *res)
156 qcom_smem_state_put(*(struct qcom_smem_state **)res);
160 * devm_qcom_smem_state_get() - acquire handle to a devres managed state
161 * @dev: client device pointer
162 * @con_id: name of the state to lookup
163 * @bit: flags from the state reference, indicating which bit's affected
165 * Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() is called
166 * automatically when @dev is removed.
168 struct qcom_smem_state *devm_qcom_smem_state_get(struct device *dev,
172 struct qcom_smem_state **ptr, *state;
174 ptr = devres_alloc(devm_qcom_smem_state_release, sizeof(*ptr), GFP_KERNEL);
176 return ERR_PTR(-ENOMEM);
178 state = qcom_smem_state_get(dev, con_id, bit);
179 if (!IS_ERR(state)) {
181 devres_add(dev, ptr);
188 EXPORT_SYMBOL_GPL(devm_qcom_smem_state_get);
191 * qcom_smem_state_register() - register a new state
192 * @of_node: of_node used for matching client lookups
193 * @ops: implementation ops
194 * @priv: implementation specific private data
196 struct qcom_smem_state *qcom_smem_state_register(struct device_node *of_node,
197 const struct qcom_smem_state_ops *ops,
200 struct qcom_smem_state *state;
202 state = kzalloc(sizeof(*state), GFP_KERNEL);
204 return ERR_PTR(-ENOMEM);
206 kref_init(&state->refcount);
208 state->of_node = of_node;
212 mutex_lock(&list_lock);
213 list_add(&state->list, &smem_states);
214 mutex_unlock(&list_lock);
218 EXPORT_SYMBOL_GPL(qcom_smem_state_register);
221 * qcom_smem_state_unregister() - unregister a registered state
222 * @state: state handle to be unregistered
224 void qcom_smem_state_unregister(struct qcom_smem_state *state)
226 state->orphan = true;
227 qcom_smem_state_put(state);
229 EXPORT_SYMBOL_GPL(qcom_smem_state_unregister);