xref: /openbmc/linux/drivers/soc/qcom/smd-rpm.c (revision 2bad466c)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015, Sony Mobile Communications AB.
4  * Copyright (c) 2012-2013, The Linux Foundation. All rights reserved.
5  */
6 
7 #include <linux/module.h>
8 #include <linux/platform_device.h>
9 #include <linux/of_platform.h>
10 #include <linux/io.h>
11 #include <linux/interrupt.h>
12 #include <linux/slab.h>
13 
14 #include <linux/rpmsg.h>
15 #include <linux/soc/qcom/smd-rpm.h>
16 
17 #define RPM_REQUEST_TIMEOUT     (5 * HZ)
18 
19 /**
20  * struct qcom_smd_rpm - state of the rpm device driver
21  * @rpm_channel:	reference to the smd channel
22  * @icc:		interconnect proxy device
23  * @dev:		rpm device
24  * @ack:		completion for acks
25  * @lock:		mutual exclusion around the send/complete pair
26  * @ack_status:		result of the rpm request
27  */
28 struct qcom_smd_rpm {
29 	struct rpmsg_endpoint *rpm_channel;
30 	struct platform_device *icc;
31 	struct device *dev;
32 
33 	struct completion ack;
34 	struct mutex lock;
35 	int ack_status;
36 };
37 
38 /**
39  * struct qcom_rpm_header - header for all rpm requests and responses
40  * @service_type:	identifier of the service
41  * @length:		length of the payload
42  */
43 struct qcom_rpm_header {
44 	__le32 service_type;
45 	__le32 length;
46 };
47 
48 /**
49  * struct qcom_rpm_request - request message to the rpm
50  * @msg_id:	identifier of the outgoing message
51  * @flags:	active/sleep state flags
52  * @type:	resource type
53  * @id:		resource id
54  * @data_len:	length of the payload following this header
55  */
56 struct qcom_rpm_request {
57 	__le32 msg_id;
58 	__le32 flags;
59 	__le32 type;
60 	__le32 id;
61 	__le32 data_len;
62 };
63 
64 /**
65  * struct qcom_rpm_message - response message from the rpm
66  * @msg_type:	indicator of the type of message
67  * @length:	the size of this message, including the message header
68  * @msg_id:	message id
69  * @message:	textual message from the rpm
70  *
71  * Multiple of these messages can be stacked in an rpm message.
72  */
73 struct qcom_rpm_message {
74 	__le32 msg_type;
75 	__le32 length;
76 	union {
77 		__le32 msg_id;
78 		DECLARE_FLEX_ARRAY(u8, message);
79 	};
80 };
81 
82 #define RPM_SERVICE_TYPE_REQUEST	0x00716572 /* "req\0" */
83 
84 #define RPM_MSG_TYPE_ERR		0x00727265 /* "err\0" */
85 #define RPM_MSG_TYPE_MSG_ID		0x2367736d /* "msg#" */
86 
87 /**
88  * qcom_rpm_smd_write - write @buf to @type:@id
89  * @rpm:	rpm handle
90  * @state:	active/sleep state flags
91  * @type:	resource type
92  * @id:		resource identifier
93  * @buf:	the data to be written
94  * @count:	number of bytes in @buf
95  */
96 int qcom_rpm_smd_write(struct qcom_smd_rpm *rpm,
97 		       int state,
98 		       u32 type, u32 id,
99 		       void *buf,
100 		       size_t count)
101 {
102 	static unsigned msg_id = 1;
103 	int left;
104 	int ret;
105 	struct {
106 		struct qcom_rpm_header hdr;
107 		struct qcom_rpm_request req;
108 		u8 payload[];
109 	} *pkt;
110 	size_t size = sizeof(*pkt) + count;
111 
112 	/* SMD packets to the RPM may not exceed 256 bytes */
113 	if (WARN_ON(size >= 256))
114 		return -EINVAL;
115 
116 	pkt = kmalloc(size, GFP_KERNEL);
117 	if (!pkt)
118 		return -ENOMEM;
119 
120 	mutex_lock(&rpm->lock);
121 
122 	pkt->hdr.service_type = cpu_to_le32(RPM_SERVICE_TYPE_REQUEST);
123 	pkt->hdr.length = cpu_to_le32(sizeof(struct qcom_rpm_request) + count);
124 
125 	pkt->req.msg_id = cpu_to_le32(msg_id++);
126 	pkt->req.flags = cpu_to_le32(state);
127 	pkt->req.type = cpu_to_le32(type);
128 	pkt->req.id = cpu_to_le32(id);
129 	pkt->req.data_len = cpu_to_le32(count);
130 	memcpy(pkt->payload, buf, count);
131 
132 	ret = rpmsg_send(rpm->rpm_channel, pkt, size);
133 	if (ret)
134 		goto out;
135 
136 	left = wait_for_completion_timeout(&rpm->ack, RPM_REQUEST_TIMEOUT);
137 	if (!left)
138 		ret = -ETIMEDOUT;
139 	else
140 		ret = rpm->ack_status;
141 
142 out:
143 	kfree(pkt);
144 	mutex_unlock(&rpm->lock);
145 	return ret;
146 }
147 EXPORT_SYMBOL(qcom_rpm_smd_write);
148 
149 static int qcom_smd_rpm_callback(struct rpmsg_device *rpdev,
150 				 void *data,
151 				 int count,
152 				 void *priv,
153 				 u32 addr)
154 {
155 	const struct qcom_rpm_header *hdr = data;
156 	size_t hdr_length = le32_to_cpu(hdr->length);
157 	const struct qcom_rpm_message *msg;
158 	struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
159 	const u8 *buf = data + sizeof(struct qcom_rpm_header);
160 	const u8 *end = buf + hdr_length;
161 	char msgbuf[32];
162 	int status = 0;
163 	u32 len, msg_length;
164 
165 	if (le32_to_cpu(hdr->service_type) != RPM_SERVICE_TYPE_REQUEST ||
166 	    hdr_length < sizeof(struct qcom_rpm_message)) {
167 		dev_err(rpm->dev, "invalid request\n");
168 		return 0;
169 	}
170 
171 	while (buf < end) {
172 		msg = (struct qcom_rpm_message *)buf;
173 		msg_length = le32_to_cpu(msg->length);
174 		switch (le32_to_cpu(msg->msg_type)) {
175 		case RPM_MSG_TYPE_MSG_ID:
176 			break;
177 		case RPM_MSG_TYPE_ERR:
178 			len = min_t(u32, ALIGN(msg_length, 4), sizeof(msgbuf));
179 			memcpy_fromio(msgbuf, msg->message, len);
180 			msgbuf[len - 1] = 0;
181 
182 			if (!strcmp(msgbuf, "resource does not exist"))
183 				status = -ENXIO;
184 			else
185 				status = -EINVAL;
186 			break;
187 		}
188 
189 		buf = PTR_ALIGN(buf + 2 * sizeof(u32) + msg_length, 4);
190 	}
191 
192 	rpm->ack_status = status;
193 	complete(&rpm->ack);
194 	return 0;
195 }
196 
197 static int qcom_smd_rpm_probe(struct rpmsg_device *rpdev)
198 {
199 	struct qcom_smd_rpm *rpm;
200 	int ret;
201 
202 	rpm = devm_kzalloc(&rpdev->dev, sizeof(*rpm), GFP_KERNEL);
203 	if (!rpm)
204 		return -ENOMEM;
205 
206 	mutex_init(&rpm->lock);
207 	init_completion(&rpm->ack);
208 
209 	rpm->dev = &rpdev->dev;
210 	rpm->rpm_channel = rpdev->ept;
211 	dev_set_drvdata(&rpdev->dev, rpm);
212 
213 	rpm->icc = platform_device_register_data(&rpdev->dev, "icc_smd_rpm", -1,
214 						 NULL, 0);
215 	if (IS_ERR(rpm->icc))
216 		return PTR_ERR(rpm->icc);
217 
218 	ret = of_platform_populate(rpdev->dev.of_node, NULL, NULL, &rpdev->dev);
219 	if (ret)
220 		platform_device_unregister(rpm->icc);
221 
222 	return ret;
223 }
224 
225 static void qcom_smd_rpm_remove(struct rpmsg_device *rpdev)
226 {
227 	struct qcom_smd_rpm *rpm = dev_get_drvdata(&rpdev->dev);
228 
229 	platform_device_unregister(rpm->icc);
230 	of_platform_depopulate(&rpdev->dev);
231 }
232 
233 static const struct of_device_id qcom_smd_rpm_of_match[] = {
234 	{ .compatible = "qcom,rpm-apq8084" },
235 	{ .compatible = "qcom,rpm-ipq6018" },
236 	{ .compatible = "qcom,rpm-ipq9574" },
237 	{ .compatible = "qcom,rpm-msm8226" },
238 	{ .compatible = "qcom,rpm-msm8909" },
239 	{ .compatible = "qcom,rpm-msm8916" },
240 	{ .compatible = "qcom,rpm-msm8936" },
241 	{ .compatible = "qcom,rpm-msm8953" },
242 	{ .compatible = "qcom,rpm-msm8974" },
243 	{ .compatible = "qcom,rpm-msm8976" },
244 	{ .compatible = "qcom,rpm-msm8994" },
245 	{ .compatible = "qcom,rpm-msm8996" },
246 	{ .compatible = "qcom,rpm-msm8998" },
247 	{ .compatible = "qcom,rpm-sdm660" },
248 	{ .compatible = "qcom,rpm-sm6115" },
249 	{ .compatible = "qcom,rpm-sm6125" },
250 	{ .compatible = "qcom,rpm-sm6375" },
251 	{ .compatible = "qcom,rpm-qcm2290" },
252 	{ .compatible = "qcom,rpm-qcs404" },
253 	{}
254 };
255 MODULE_DEVICE_TABLE(of, qcom_smd_rpm_of_match);
256 
257 static struct rpmsg_driver qcom_smd_rpm_driver = {
258 	.probe = qcom_smd_rpm_probe,
259 	.remove = qcom_smd_rpm_remove,
260 	.callback = qcom_smd_rpm_callback,
261 	.drv  = {
262 		.name  = "qcom_smd_rpm",
263 		.of_match_table = qcom_smd_rpm_of_match,
264 	},
265 };
266 
267 static int __init qcom_smd_rpm_init(void)
268 {
269 	return register_rpmsg_driver(&qcom_smd_rpm_driver);
270 }
271 arch_initcall(qcom_smd_rpm_init);
272 
273 static void __exit qcom_smd_rpm_exit(void)
274 {
275 	unregister_rpmsg_driver(&qcom_smd_rpm_driver);
276 }
277 module_exit(qcom_smd_rpm_exit);
278 
279 MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>");
280 MODULE_DESCRIPTION("Qualcomm SMD backed RPM driver");
281 MODULE_LICENSE("GPL v2");
282