Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015, Sony Mobile Communications Inc. |
| 3 | * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved. |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 and |
| 7 | * only version 2 as published by the Free Software Foundation. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU General Public License for more details. |
| 13 | */ |
| 14 | #include <linux/device.h> |
| 15 | #include <linux/list.h> |
| 16 | #include <linux/module.h> |
| 17 | #include <linux/of.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/soc/qcom/smem_state.h> |
| 20 | |
| 21 | static LIST_HEAD(smem_states); |
| 22 | static DEFINE_MUTEX(list_lock); |
| 23 | |
| 24 | /** |
| 25 | * struct qcom_smem_state - state context |
| 26 | * @refcount: refcount for the state |
| 27 | * @orphan: boolean indicator that this state has been unregistered |
| 28 | * @list: entry in smem_states list |
| 29 | * @of_node: of_node to use for matching the state in DT |
| 30 | * @priv: implementation private data |
| 31 | * @ops: ops for the state |
| 32 | */ |
| 33 | struct qcom_smem_state { |
| 34 | struct kref refcount; |
| 35 | bool orphan; |
| 36 | |
| 37 | struct list_head list; |
| 38 | struct device_node *of_node; |
| 39 | |
| 40 | void *priv; |
| 41 | |
| 42 | struct qcom_smem_state_ops ops; |
| 43 | }; |
| 44 | |
| 45 | /** |
| 46 | * qcom_smem_state_update_bits() - update the masked bits in state with value |
| 47 | * @state: state handle acquired by calling qcom_smem_state_get() |
| 48 | * @mask: bit mask for the change |
| 49 | * @value: new value for the masked bits |
| 50 | * |
| 51 | * Returns 0 on success, otherwise negative errno. |
| 52 | */ |
| 53 | int qcom_smem_state_update_bits(struct qcom_smem_state *state, |
| 54 | u32 mask, |
| 55 | u32 value) |
| 56 | { |
| 57 | if (state->orphan) |
| 58 | return -ENXIO; |
| 59 | |
| 60 | if (!state->ops.update_bits) |
| 61 | return -ENOTSUPP; |
| 62 | |
| 63 | return state->ops.update_bits(state->priv, mask, value); |
| 64 | } |
| 65 | EXPORT_SYMBOL_GPL(qcom_smem_state_update_bits); |
| 66 | |
| 67 | static struct qcom_smem_state *of_node_to_state(struct device_node *np) |
| 68 | { |
| 69 | struct qcom_smem_state *state; |
| 70 | |
| 71 | mutex_lock(&list_lock); |
| 72 | |
| 73 | list_for_each_entry(state, &smem_states, list) { |
| 74 | if (state->of_node == np) { |
| 75 | kref_get(&state->refcount); |
| 76 | goto unlock; |
| 77 | } |
| 78 | } |
| 79 | state = ERR_PTR(-EPROBE_DEFER); |
| 80 | |
| 81 | unlock: |
| 82 | mutex_unlock(&list_lock); |
| 83 | |
| 84 | return state; |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * qcom_smem_state_get() - acquire handle to a state |
| 89 | * @dev: client device pointer |
| 90 | * @con_id: name of the state to lookup |
| 91 | * @bit: flags from the state reference, indicating which bit's affected |
| 92 | * |
| 93 | * Returns handle to the state, or ERR_PTR(). qcom_smem_state_put() must be |
| 94 | * called to release the returned state handle. |
| 95 | */ |
| 96 | struct qcom_smem_state *qcom_smem_state_get(struct device *dev, |
| 97 | const char *con_id, |
| 98 | unsigned *bit) |
| 99 | { |
| 100 | struct qcom_smem_state *state; |
| 101 | struct of_phandle_args args; |
| 102 | int index = 0; |
| 103 | int ret; |
| 104 | |
| 105 | if (con_id) { |
| 106 | index = of_property_match_string(dev->of_node, |
Bjorn Andersson | 3680a4a | 2016-06-09 21:11:22 -0700 | [diff] [blame] | 107 | "qcom,smem-state-names", |
Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 108 | con_id); |
| 109 | if (index < 0) { |
Bjorn Andersson | 3680a4a | 2016-06-09 21:11:22 -0700 | [diff] [blame] | 110 | dev_err(dev, "missing qcom,smem-state-names\n"); |
Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 111 | return ERR_PTR(index); |
| 112 | } |
| 113 | } |
| 114 | |
| 115 | ret = of_parse_phandle_with_args(dev->of_node, |
Bjorn Andersson | 3680a4a | 2016-06-09 21:11:22 -0700 | [diff] [blame] | 116 | "qcom,smem-states", |
| 117 | "#qcom,smem-state-cells", |
Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 118 | index, |
| 119 | &args); |
| 120 | if (ret) { |
Bjorn Andersson | 3680a4a | 2016-06-09 21:11:22 -0700 | [diff] [blame] | 121 | dev_err(dev, "failed to parse qcom,smem-states property\n"); |
Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 122 | return ERR_PTR(ret); |
| 123 | } |
| 124 | |
| 125 | if (args.args_count != 1) { |
Bjorn Andersson | 3680a4a | 2016-06-09 21:11:22 -0700 | [diff] [blame] | 126 | dev_err(dev, "invalid #qcom,smem-state-cells\n"); |
Bjorn Andersson | 9460ae2 | 2015-09-24 18:25:01 -0700 | [diff] [blame] | 127 | return ERR_PTR(-EINVAL); |
| 128 | } |
| 129 | |
| 130 | state = of_node_to_state(args.np); |
| 131 | if (IS_ERR(state)) |
| 132 | goto put; |
| 133 | |
| 134 | *bit = args.args[0]; |
| 135 | |
| 136 | put: |
| 137 | of_node_put(args.np); |
| 138 | return state; |
| 139 | } |
| 140 | EXPORT_SYMBOL_GPL(qcom_smem_state_get); |
| 141 | |
| 142 | static void qcom_smem_state_release(struct kref *ref) |
| 143 | { |
| 144 | struct qcom_smem_state *state = container_of(ref, struct qcom_smem_state, refcount); |
| 145 | |
| 146 | list_del(&state->list); |
| 147 | kfree(state); |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * qcom_smem_state_put() - release state handle |
| 152 | * @state: state handle to be released |
| 153 | */ |
| 154 | void qcom_smem_state_put(struct qcom_smem_state *state) |
| 155 | { |
| 156 | mutex_lock(&list_lock); |
| 157 | kref_put(&state->refcount, qcom_smem_state_release); |
| 158 | mutex_unlock(&list_lock); |
| 159 | } |
| 160 | EXPORT_SYMBOL_GPL(qcom_smem_state_put); |
| 161 | |
| 162 | /** |
| 163 | * qcom_smem_state_register() - register a new state |
| 164 | * @of_node: of_node used for matching client lookups |
| 165 | * @ops: implementation ops |
| 166 | * @priv: implementation specific private data |
| 167 | */ |
| 168 | struct qcom_smem_state *qcom_smem_state_register(struct device_node *of_node, |
| 169 | const struct qcom_smem_state_ops *ops, |
| 170 | void *priv) |
| 171 | { |
| 172 | struct qcom_smem_state *state; |
| 173 | |
| 174 | state = kzalloc(sizeof(*state), GFP_KERNEL); |
| 175 | if (!state) |
| 176 | return ERR_PTR(-ENOMEM); |
| 177 | |
| 178 | kref_init(&state->refcount); |
| 179 | |
| 180 | state->of_node = of_node; |
| 181 | state->ops = *ops; |
| 182 | state->priv = priv; |
| 183 | |
| 184 | mutex_lock(&list_lock); |
| 185 | list_add(&state->list, &smem_states); |
| 186 | mutex_unlock(&list_lock); |
| 187 | |
| 188 | return state; |
| 189 | } |
| 190 | EXPORT_SYMBOL_GPL(qcom_smem_state_register); |
| 191 | |
| 192 | /** |
| 193 | * qcom_smem_state_unregister() - unregister a registered state |
| 194 | * @state: state handle to be unregistered |
| 195 | */ |
| 196 | void qcom_smem_state_unregister(struct qcom_smem_state *state) |
| 197 | { |
| 198 | state->orphan = true; |
| 199 | qcom_smem_state_put(state); |
| 200 | } |
| 201 | EXPORT_SYMBOL_GPL(qcom_smem_state_unregister); |