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193 lines
4.5 KiB
193 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* Copyright (c) 2015, Sony Mobile Communications Inc. |
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* Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. |
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*/ |
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#include <linux/device.h> |
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#include <linux/list.h> |
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#include <linux/module.h> |
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#include <linux/of.h> |
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#include <linux/slab.h> |
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#include <linux/soc/qcom/smem_state.h> |
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static LIST_HEAD(smem_states); |
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static DEFINE_MUTEX(list_lock); |
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/** |
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* struct qcom_smem_state - state context |
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* @refcount: refcount for the state |
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* @orphan: boolean indicator that this state has been unregistered |
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* @list: entry in smem_states list |
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* @of_node: of_node to use for matching the state in DT |
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* @priv: implementation private data |
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* @ops: ops for the state |
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*/ |
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struct qcom_smem_state { |
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struct kref refcount; |
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bool orphan; |
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struct list_head list; |
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struct device_node *of_node; |
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void *priv; |
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struct qcom_smem_state_ops ops; |
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}; |
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/** |
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* qcom_smem_state_update_bits() - update the masked bits in state with value |
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* @state: state handle acquired by calling qcom_smem_state_get() |
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* @mask: bit mask for the change |
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* @value: new value for the masked bits |
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* |
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* Returns 0 on success, otherwise negative errno. |
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*/ |
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int qcom_smem_state_update_bits(struct qcom_smem_state *state, |
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u32 mask, |
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u32 value) |
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{ |
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if (state->orphan) |
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return -ENXIO; |
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if (!state->ops.update_bits) |
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return -ENOTSUPP; |
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return state->ops.update_bits(state->priv, mask, value); |
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} |
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EXPORT_SYMBOL_GPL(qcom_smem_state_update_bits); |
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static struct qcom_smem_state *of_node_to_state(struct device_node *np) |
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{ |
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struct qcom_smem_state *state; |
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mutex_lock(&list_lock); |
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list_for_each_entry(state, &smem_states, list) { |
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if (state->of_node == np) { |
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kref_get(&state->refcount); |
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goto unlock; |
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} |
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} |
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state = ERR_PTR(-EPROBE_DEFER); |
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unlock: |
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mutex_unlock(&list_lock); |
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return state; |
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} |
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/** |
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* qcom_smem_state_get() - acquire handle to a state |
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* @dev: client device pointer |
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* @con_id: name of the state to lookup |
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* @bit: flags from the state reference, indicating which bit's affected |
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* |
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* Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() must be |
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* called to release the returned state handle. |
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*/ |
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struct qcom_smem_state *qcom_smem_state_get(struct device *dev, |
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const char *con_id, |
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unsigned *bit) |
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{ |
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struct qcom_smem_state *state; |
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struct of_phandle_args args; |
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int index = 0; |
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int ret; |
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if (con_id) { |
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index = of_property_match_string(dev->of_node, |
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"qcom,smem-state-names", |
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con_id); |
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if (index < 0) { |
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dev_err(dev, "missing qcom,smem-state-names\n"); |
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return ERR_PTR(index); |
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} |
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} |
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ret = of_parse_phandle_with_args(dev->of_node, |
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"qcom,smem-states", |
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"#qcom,smem-state-cells", |
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index, |
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&args); |
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if (ret) { |
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dev_err(dev, "failed to parse qcom,smem-states property\n"); |
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return ERR_PTR(ret); |
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} |
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if (args.args_count != 1) { |
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dev_err(dev, "invalid #qcom,smem-state-cells\n"); |
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return ERR_PTR(-EINVAL); |
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} |
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state = of_node_to_state(args.np); |
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if (IS_ERR(state)) |
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goto put; |
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*bit = args.args[0]; |
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put: |
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of_node_put(args.np); |
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return state; |
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} |
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EXPORT_SYMBOL_GPL(qcom_smem_state_get); |
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static void qcom_smem_state_release(struct kref *ref) |
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{ |
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struct qcom_smem_state *state = container_of(ref, struct qcom_smem_state, refcount); |
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list_del(&state->list); |
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kfree(state); |
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} |
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/** |
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* qcom_smem_state_put() - release state handle |
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* @state: state handle to be released |
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*/ |
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void qcom_smem_state_put(struct qcom_smem_state *state) |
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{ |
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mutex_lock(&list_lock); |
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kref_put(&state->refcount, qcom_smem_state_release); |
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mutex_unlock(&list_lock); |
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} |
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EXPORT_SYMBOL_GPL(qcom_smem_state_put); |
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/** |
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* qcom_smem_state_register() - register a new state |
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* @of_node: of_node used for matching client lookups |
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* @ops: implementation ops |
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* @priv: implementation specific private data |
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*/ |
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struct qcom_smem_state *qcom_smem_state_register(struct device_node *of_node, |
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const struct qcom_smem_state_ops *ops, |
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void *priv) |
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{ |
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struct qcom_smem_state *state; |
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state = kzalloc(sizeof(*state), GFP_KERNEL); |
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if (!state) |
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return ERR_PTR(-ENOMEM); |
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kref_init(&state->refcount); |
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state->of_node = of_node; |
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state->ops = *ops; |
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state->priv = priv; |
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mutex_lock(&list_lock); |
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list_add(&state->list, &smem_states); |
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mutex_unlock(&list_lock); |
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return state; |
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} |
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EXPORT_SYMBOL_GPL(qcom_smem_state_register); |
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/** |
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* qcom_smem_state_unregister() - unregister a registered state |
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* @state: state handle to be unregistered |
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*/ |
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void qcom_smem_state_unregister(struct qcom_smem_state *state) |
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{ |
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state->orphan = true; |
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qcom_smem_state_put(state); |
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} |
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EXPORT_SYMBOL_GPL(qcom_smem_state_unregister);
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