1 // SPDX-License-Identifier: GPL-2.0
3 // Copyright 2018 Google LLC.
5 #include <linux/completion.h>
6 #include <linux/delay.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
10 #include <linux/platform_data/cros_ec_commands.h>
11 #include <linux/platform_data/cros_ec_proto.h>
12 #include <linux/platform_device.h>
13 #include <linux/rpmsg.h>
14 #include <linux/slab.h>
18 #define EC_MSG_TIMEOUT_MS 200
19 #define HOST_COMMAND_MARK 1
20 #define HOST_EVENT_MARK 2
23 * struct cros_ec_rpmsg_response - rpmsg message format from from EC.
25 * @type: The type of message, should be either HOST_COMMAND_MARK or
26 * HOST_EVENT_MARK, representing that the message is a response to
27 * host command, or a host event.
28 * @data: ec_host_response for host command.
30 struct cros_ec_rpmsg_response {
32 u8 data[] __aligned(4);
36 * struct cros_ec_rpmsg - information about a EC over rpmsg.
38 * @rpdev: rpmsg device we are connected to
39 * @xfer_ack: completion for host command transfer.
40 * @host_event_work: Work struct for pending host event.
42 struct cros_ec_rpmsg {
43 struct rpmsg_device *rpdev;
44 struct completion xfer_ack;
45 struct work_struct host_event_work;
46 struct rpmsg_endpoint *ept;
50 * cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply
52 * @ec_dev: ChromeOS EC device
53 * @ec_msg: Message to transfer
55 * This is only used for old EC proto version, and is not supported for this
60 static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev,
61 struct cros_ec_command *ec_msg)
67 * cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply
69 * @ec_dev: ChromeOS EC device
70 * @ec_msg: Message to transfer
72 * Return: number of bytes of the reply on success or negative error code.
74 static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev,
75 struct cros_ec_command *ec_msg)
77 struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
78 struct ec_host_response *response;
79 unsigned long timeout;
86 len = cros_ec_prepare_tx(ec_dev, ec_msg);
87 dev_dbg(ec_dev->dev, "prepared, len=%d\n", len);
89 reinit_completion(&ec_rpmsg->xfer_ack);
90 ret = rpmsg_send(ec_rpmsg->ept, ec_dev->dout, len);
92 dev_err(ec_dev->dev, "rpmsg send failed\n");
96 timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS);
97 ret = wait_for_completion_timeout(&ec_rpmsg->xfer_ack, timeout);
99 dev_err(ec_dev->dev, "rpmsg send timeout\n");
103 /* check response error code */
104 response = (struct ec_host_response *)ec_dev->din;
105 ec_msg->result = response->result;
107 ret = cros_ec_check_result(ec_dev, ec_msg);
111 if (response->data_len > ec_msg->insize) {
112 dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)",
113 response->data_len, ec_msg->insize);
118 /* copy response packet payload and compute checksum */
119 memcpy(ec_msg->data, ec_dev->din + sizeof(*response),
123 for (i = 0; i < sizeof(*response) + response->data_len; i++)
124 sum += ec_dev->din[i];
127 dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n",
133 ret = response->data_len;
135 if (ec_msg->command == EC_CMD_REBOOT_EC)
136 msleep(EC_REBOOT_DELAY_MS);
142 cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work)
144 struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work,
145 struct cros_ec_rpmsg,
147 struct cros_ec_device *ec_dev = dev_get_drvdata(&ec_rpmsg->rpdev->dev);
148 bool ec_has_more_events;
151 ec_has_more_events = cros_ec_handle_event(ec_dev);
152 } while (ec_has_more_events);
155 static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data,
156 int len, void *priv, u32 src)
158 struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
159 struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
160 struct cros_ec_rpmsg_response *resp;
163 dev_warn(ec_dev->dev, "rpmsg received empty response");
168 len -= offsetof(struct cros_ec_rpmsg_response, data);
169 if (resp->type == HOST_COMMAND_MARK) {
170 if (len > ec_dev->din_size) {
171 dev_warn(ec_dev->dev,
172 "received length %d > din_size %d, truncating",
173 len, ec_dev->din_size);
174 len = ec_dev->din_size;
177 memcpy(ec_dev->din, resp->data, len);
178 complete(&ec_rpmsg->xfer_ack);
179 } else if (resp->type == HOST_EVENT_MARK) {
180 schedule_work(&ec_rpmsg->host_event_work);
182 dev_warn(ec_dev->dev, "rpmsg received invalid type = %d",
190 static struct rpmsg_endpoint *
191 cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev)
193 struct rpmsg_channel_info chinfo = {};
195 strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE);
196 chinfo.src = rpdev->src;
197 chinfo.dst = RPMSG_ADDR_ANY;
199 return rpmsg_create_ept(rpdev, cros_ec_rpmsg_callback, NULL, chinfo);
202 static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev)
204 struct device *dev = &rpdev->dev;
205 struct cros_ec_rpmsg *ec_rpmsg;
206 struct cros_ec_device *ec_dev;
209 ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
213 ec_rpmsg = devm_kzalloc(dev, sizeof(*ec_rpmsg), GFP_KERNEL);
218 ec_dev->priv = ec_rpmsg;
219 ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg;
220 ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg;
221 ec_dev->phys_name = dev_name(&rpdev->dev);
222 ec_dev->din_size = sizeof(struct ec_host_response) +
223 sizeof(struct ec_response_get_protocol_info);
224 ec_dev->dout_size = sizeof(struct ec_host_request);
225 dev_set_drvdata(dev, ec_dev);
227 ec_rpmsg->rpdev = rpdev;
228 init_completion(&ec_rpmsg->xfer_ack);
229 INIT_WORK(&ec_rpmsg->host_event_work,
230 cros_ec_rpmsg_host_event_function);
232 ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev);
236 ret = cros_ec_register(ec_dev);
238 rpmsg_destroy_ept(ec_rpmsg->ept);
239 cancel_work_sync(&ec_rpmsg->host_event_work);
246 static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev)
248 struct cros_ec_device *ec_dev = dev_get_drvdata(&rpdev->dev);
249 struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv;
251 cros_ec_unregister(ec_dev);
252 rpmsg_destroy_ept(ec_rpmsg->ept);
253 cancel_work_sync(&ec_rpmsg->host_event_work);
256 #ifdef CONFIG_PM_SLEEP
257 static int cros_ec_rpmsg_suspend(struct device *dev)
259 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
261 return cros_ec_suspend(ec_dev);
264 static int cros_ec_rpmsg_resume(struct device *dev)
266 struct cros_ec_device *ec_dev = dev_get_drvdata(dev);
268 return cros_ec_resume(ec_dev);
272 static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend,
273 cros_ec_rpmsg_resume);
275 static const struct of_device_id cros_ec_rpmsg_of_match[] = {
276 { .compatible = "google,cros-ec-rpmsg", },
279 MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match);
281 static struct rpmsg_driver cros_ec_driver_rpmsg = {
283 .name = "cros-ec-rpmsg",
284 .of_match_table = cros_ec_rpmsg_of_match,
285 .pm = &cros_ec_rpmsg_pm_ops,
287 .probe = cros_ec_rpmsg_probe,
288 .remove = cros_ec_rpmsg_remove,
291 module_rpmsg_driver(cros_ec_driver_rpmsg);
293 MODULE_LICENSE("GPL v2");
294 MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)");