Merge branch 'for-linus-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/mason...
[linux-2.6-block.git] / drivers / soc / qcom / smd-rpm.c
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1/*
2 * Copyright (c) 2015, Sony Mobile Communications AB.
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
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/of_platform.h>
18#include <linux/io.h>
19#include <linux/interrupt.h>
50e1b29b 20#include <linux/slab.h>
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21
22#include <linux/soc/qcom/smd.h>
23#include <linux/soc/qcom/smd-rpm.h>
24
25#define RPM_REQUEST_TIMEOUT (5 * HZ)
26
27/**
28 * struct qcom_smd_rpm - state of the rpm device driver
29 * @rpm_channel: reference to the smd channel
30 * @ack: completion for acks
31 * @lock: mutual exclusion around the send/complete pair
32 * @ack_status: result of the rpm request
33 */
34struct qcom_smd_rpm {
35 struct qcom_smd_channel *rpm_channel;
b853cb96 36 struct device *dev;
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37
38 struct completion ack;
39 struct mutex lock;
40 int ack_status;
41};
42
43/**
44 * struct qcom_rpm_header - header for all rpm requests and responses
45 * @service_type: identifier of the service
46 * @length: length of the payload
47 */
48struct qcom_rpm_header {
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49 __le32 service_type;
50 __le32 length;
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51};
52
53/**
54 * struct qcom_rpm_request - request message to the rpm
55 * @msg_id: identifier of the outgoing message
56 * @flags: active/sleep state flags
57 * @type: resource type
58 * @id: resource id
59 * @data_len: length of the payload following this header
60 */
61struct qcom_rpm_request {
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62 __le32 msg_id;
63 __le32 flags;
64 __le32 type;
65 __le32 id;
66 __le32 data_len;
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67};
68
69/**
70 * struct qcom_rpm_message - response message from the rpm
71 * @msg_type: indicator of the type of message
72 * @length: the size of this message, including the message header
73 * @msg_id: message id
74 * @message: textual message from the rpm
75 *
76 * Multiple of these messages can be stacked in an rpm message.
77 */
78struct qcom_rpm_message {
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79 __le32 msg_type;
80 __le32 length;
936f14cf 81 union {
30b7ea5e 82 __le32 msg_id;
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83 u8 message[0];
84 };
85};
86
87#define RPM_SERVICE_TYPE_REQUEST 0x00716572 /* "req\0" */
88
89#define RPM_MSG_TYPE_ERR 0x00727265 /* "err\0" */
90#define RPM_MSG_TYPE_MSG_ID 0x2367736d /* "msg#" */
91
92/**
93 * qcom_rpm_smd_write - write @buf to @type:@id
94 * @rpm: rpm handle
95 * @type: resource type
96 * @id: resource identifier
97 * @buf: the data to be written
98 * @count: number of bytes in @buf
99 */
100int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
101 int state,
102 u32 type, u32 id,
103 void *buf,
104 size_t count)
105{
106 static unsigned msg_id = 1;
107 int left;
108 int ret;
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109 struct {
110 struct qcom_rpm_header hdr;
111 struct qcom_rpm_request req;
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112 u8 payload[];
113 } *pkt;
114 size_t size = sizeof(*pkt) + count;
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115
116 /* SMD packets to the RPM may not exceed 256 bytes */
50e1b29b 117 if (WARN_ON(size >= 256))
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118 return -EINVAL;
119
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120 pkt = kmalloc(size, GFP_KERNEL);
121 if (!pkt)
122 return -ENOMEM;
123
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124 mutex_lock(&rpm->lock);
125
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126 pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
127 pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
936f14cf 128
30b7ea5e 129 pkt->req.msg_id = cpu_to_le32(msg_id++);
a8ddd1b9 130 pkt->req.flags = cpu_to_le32(state);
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131 pkt->req.type = cpu_to_le32(type);
132 pkt->req.id = cpu_to_le32(id);
133 pkt->req.data_len = cpu_to_le32(count);
50e1b29b 134 memcpy(pkt->payload, buf, count);
936f14cf 135
d13a5c8c 136 ret = qcom_smd_send(rpm->rpm_channel, pkt, size);
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137 if (ret)
138 goto out;
139
140 left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
141 if (!left)
142 ret = -ETIMEDOUT;
143 else
144 ret = rpm->ack_status;
145
146out:
50e1b29b 147 kfree(pkt);
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148 mutex_unlock(&rpm->lock);
149 return ret;
150}
151EXPORT_SYMBOL(qcom_rpm_smd_write);
152
b853cb96 153static int qcom_smd_rpm_callback(struct qcom_smd_channel *channel,
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154 const void *data,
155 size_t count)
156{
157 const struct qcom_rpm_header *hdr = data;
30b7ea5e 158 size_t hdr_length = le32_to_cpu(hdr->length);
936f14cf 159 const struct qcom_rpm_message *msg;
b853cb96 160 struct qcom_smd_rpm *rpm = qcom_smd_get_drvdata(channel);
936f14cf 161 const u8 *buf = data + sizeof(struct qcom_rpm_header);
30b7ea5e 162 const u8 *end = buf + hdr_length;
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163 char msgbuf[32];
164 int status = 0;
30b7ea5e 165 u32 len, msg_length;
936f14cf 166
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167 if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
168 hdr_length < sizeof(struct qcom_rpm_message)) {
b853cb96 169 dev_err(rpm->dev, "invalid request\n");
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170 return 0;
171 }
172
173 while (buf < end) {
174 msg = (struct qcom_rpm_message *)buf;
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175 msg_length = le32_to_cpu(msg->length);
176 switch (le32_to_cpu(msg->msg_type)) {
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177 case RPM_MSG_TYPE_MSG_ID:
178 break;
179 case RPM_MSG_TYPE_ERR:
30b7ea5e 180 len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
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181 memcpy_fromio(msgbuf, msg->message, len);
182 msgbuf[len - 1] = 0;
183
184 if (!strcmp(msgbuf, "resource does not exist"))
185 status = -ENXIO;
186 else
187 status = -EINVAL;
188 break;
189 }
190
30b7ea5e 191 buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
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192 }
193
194 rpm->ack_status = status;
195 complete(&rpm->ack);
196 return 0;
197}
198
199static int qcom_smd_rpm_probe(struct qcom_smd_device *sdev)
200{
201 struct qcom_smd_rpm *rpm;
202
203 rpm = devm_kzalloc(&sdev->dev, sizeof(*rpm), GFP_KERNEL);
204 if (!rpm)
205 return -ENOMEM;
206
207 mutex_init(&rpm->lock);
208 init_completion(&rpm->ack);
209
b853cb96 210 rpm->dev = &sdev->dev;
936f14cf 211 rpm->rpm_channel = sdev->channel;
b853cb96 212 qcom_smd_set_drvdata(sdev->channel, rpm);
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213
214 dev_set_drvdata(&sdev->dev, rpm);
215
216 return of_platform_populate(sdev->dev.of_node, NULL, NULL, &sdev->dev);
217}
218
219static void qcom_smd_rpm_remove(struct qcom_smd_device *sdev)
220{
221 of_platform_depopulate(&sdev->dev);
222}
223
224static const struct of_device_id qcom_smd_rpm_of_match[] = {
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225 { .compatible = "qcom,rpm-apq8084" },
226 { .compatible = "qcom,rpm-msm8916" },
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227 { .compatible = "qcom,rpm-msm8974" },
228 {}
229};
230MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
231
232static struct qcom_smd_driver qcom_smd_rpm_driver = {
233 .probe = qcom_smd_rpm_probe,
234 .remove = qcom_smd_rpm_remove,
235 .callback = qcom_smd_rpm_callback,
236 .driver = {
237 .name = "qcom_smd_rpm",
238 .owner = THIS_MODULE,
239 .of_match_table = qcom_smd_rpm_of_match,
240 },
241};
242
243static int __init qcom_smd_rpm_init(void)
244{
245 return qcom_smd_driver_register(&qcom_smd_rpm_driver);
246}
247arch_initcall(qcom_smd_rpm_init);
248
249static void __exit qcom_smd_rpm_exit(void)
250{
251 qcom_smd_driver_unregister(&qcom_smd_rpm_driver);
252}
253module_exit(qcom_smd_rpm_exit);
254
255MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
256MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
257MODULE_LICENSE("GPL v2");