1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // |
3 | // Copyright 2018 Google LLC. |
4 | |
5 | #include <linux/completion.h> |
6 | #include <linux/delay.h> |
7 | #include <linux/kernel.h> |
8 | #include <linux/module.h> |
9 | #include <linux/of.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> |
15 | |
16 | #include "cros_ec.h" |
17 | |
18 | #define EC_MSG_TIMEOUT_MS 200 |
19 | #define HOST_COMMAND_MARK 1 |
20 | #define HOST_EVENT_MARK 2 |
21 | |
22 | /** |
23 | * struct cros_ec_rpmsg_response - rpmsg message format from from EC. |
24 | * |
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. |
29 | */ |
30 | struct cros_ec_rpmsg_response { |
31 | u8 type; |
32 | u8 data[] __aligned(4); |
33 | }; |
34 | |
35 | /** |
36 | * struct cros_ec_rpmsg - information about a EC over rpmsg. |
37 | * |
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. |
41 | * @ept: The rpmsg endpoint of this channel. |
42 | * @has_pending_host_event: Boolean used to check if there is a pending event. |
43 | * @probe_done: Flag to indicate that probe is done. |
44 | */ |
45 | struct cros_ec_rpmsg { |
46 | struct rpmsg_device *rpdev; |
47 | struct completion xfer_ack; |
48 | struct work_struct host_event_work; |
49 | struct rpmsg_endpoint *ept; |
50 | bool has_pending_host_event; |
51 | bool probe_done; |
52 | }; |
53 | |
54 | /** |
55 | * cros_ec_cmd_xfer_rpmsg - Transfer a message over rpmsg and receive the reply |
56 | * |
57 | * @ec_dev: ChromeOS EC device |
58 | * @ec_msg: Message to transfer |
59 | * |
60 | * This is only used for old EC proto version, and is not supported for this |
61 | * driver. |
62 | * |
63 | * Return: -EINVAL |
64 | */ |
65 | static int cros_ec_cmd_xfer_rpmsg(struct cros_ec_device *ec_dev, |
66 | struct cros_ec_command *ec_msg) |
67 | { |
68 | return -EINVAL; |
69 | } |
70 | |
71 | /** |
72 | * cros_ec_pkt_xfer_rpmsg - Transfer a packet over rpmsg and receive the reply |
73 | * |
74 | * @ec_dev: ChromeOS EC device |
75 | * @ec_msg: Message to transfer |
76 | * |
77 | * Return: number of bytes of the reply on success or negative error code. |
78 | */ |
79 | static int cros_ec_pkt_xfer_rpmsg(struct cros_ec_device *ec_dev, |
80 | struct cros_ec_command *ec_msg) |
81 | { |
82 | struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
83 | struct ec_host_response *response; |
84 | unsigned long timeout; |
85 | int len; |
86 | int ret; |
87 | u8 sum; |
88 | int i; |
89 | |
90 | ec_msg->result = 0; |
91 | len = cros_ec_prepare_tx(ec_dev, msg: ec_msg); |
92 | if (len < 0) |
93 | return len; |
94 | dev_dbg(ec_dev->dev, "prepared, len=%d\n" , len); |
95 | |
96 | reinit_completion(x: &ec_rpmsg->xfer_ack); |
97 | ret = rpmsg_send(ept: ec_rpmsg->ept, data: ec_dev->dout, len); |
98 | if (ret) { |
99 | dev_err(ec_dev->dev, "rpmsg send failed\n" ); |
100 | return ret; |
101 | } |
102 | |
103 | timeout = msecs_to_jiffies(EC_MSG_TIMEOUT_MS); |
104 | ret = wait_for_completion_timeout(x: &ec_rpmsg->xfer_ack, timeout); |
105 | if (!ret) { |
106 | dev_err(ec_dev->dev, "rpmsg send timeout\n" ); |
107 | return -EIO; |
108 | } |
109 | |
110 | /* check response error code */ |
111 | response = (struct ec_host_response *)ec_dev->din; |
112 | ec_msg->result = response->result; |
113 | |
114 | ret = cros_ec_check_result(ec_dev, msg: ec_msg); |
115 | if (ret) |
116 | goto exit; |
117 | |
118 | if (response->data_len > ec_msg->insize) { |
119 | dev_err(ec_dev->dev, "packet too long (%d bytes, expected %d)" , |
120 | response->data_len, ec_msg->insize); |
121 | ret = -EMSGSIZE; |
122 | goto exit; |
123 | } |
124 | |
125 | /* copy response packet payload and compute checksum */ |
126 | memcpy(ec_msg->data, ec_dev->din + sizeof(*response), |
127 | response->data_len); |
128 | |
129 | sum = 0; |
130 | for (i = 0; i < sizeof(*response) + response->data_len; i++) |
131 | sum += ec_dev->din[i]; |
132 | |
133 | if (sum) { |
134 | dev_err(ec_dev->dev, "bad packet checksum, calculated %x\n" , |
135 | sum); |
136 | ret = -EBADMSG; |
137 | goto exit; |
138 | } |
139 | |
140 | ret = response->data_len; |
141 | exit: |
142 | if (ec_msg->command == EC_CMD_REBOOT_EC) |
143 | msleep(EC_REBOOT_DELAY_MS); |
144 | |
145 | return ret; |
146 | } |
147 | |
148 | static void |
149 | cros_ec_rpmsg_host_event_function(struct work_struct *host_event_work) |
150 | { |
151 | struct cros_ec_rpmsg *ec_rpmsg = container_of(host_event_work, |
152 | struct cros_ec_rpmsg, |
153 | host_event_work); |
154 | |
155 | cros_ec_irq_thread(irq: 0, data: dev_get_drvdata(dev: &ec_rpmsg->rpdev->dev)); |
156 | } |
157 | |
158 | static int cros_ec_rpmsg_callback(struct rpmsg_device *rpdev, void *data, |
159 | int len, void *priv, u32 src) |
160 | { |
161 | struct cros_ec_device *ec_dev = dev_get_drvdata(dev: &rpdev->dev); |
162 | struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
163 | struct cros_ec_rpmsg_response *resp; |
164 | |
165 | if (!len) { |
166 | dev_warn(ec_dev->dev, "rpmsg received empty response" ); |
167 | return -EINVAL; |
168 | } |
169 | |
170 | resp = data; |
171 | len -= offsetof(struct cros_ec_rpmsg_response, data); |
172 | if (resp->type == HOST_COMMAND_MARK) { |
173 | if (len > ec_dev->din_size) { |
174 | dev_warn(ec_dev->dev, |
175 | "received length %d > din_size %d, truncating" , |
176 | len, ec_dev->din_size); |
177 | len = ec_dev->din_size; |
178 | } |
179 | |
180 | memcpy(ec_dev->din, resp->data, len); |
181 | complete(&ec_rpmsg->xfer_ack); |
182 | } else if (resp->type == HOST_EVENT_MARK) { |
183 | /* |
184 | * If the host event is sent before cros_ec_register is |
185 | * finished, queue the host event. |
186 | */ |
187 | if (ec_rpmsg->probe_done) |
188 | schedule_work(work: &ec_rpmsg->host_event_work); |
189 | else |
190 | ec_rpmsg->has_pending_host_event = true; |
191 | } else { |
192 | dev_warn(ec_dev->dev, "rpmsg received invalid type = %d" , |
193 | resp->type); |
194 | return -EINVAL; |
195 | } |
196 | |
197 | return 0; |
198 | } |
199 | |
200 | static struct rpmsg_endpoint * |
201 | cros_ec_rpmsg_create_ept(struct rpmsg_device *rpdev) |
202 | { |
203 | struct rpmsg_channel_info chinfo = {}; |
204 | |
205 | strscpy(chinfo.name, rpdev->id.name, RPMSG_NAME_SIZE); |
206 | chinfo.src = rpdev->src; |
207 | chinfo.dst = RPMSG_ADDR_ANY; |
208 | |
209 | return rpmsg_create_ept(rpdev, cb: cros_ec_rpmsg_callback, NULL, chinfo); |
210 | } |
211 | |
212 | static int cros_ec_rpmsg_probe(struct rpmsg_device *rpdev) |
213 | { |
214 | struct device *dev = &rpdev->dev; |
215 | struct cros_ec_rpmsg *ec_rpmsg; |
216 | struct cros_ec_device *ec_dev; |
217 | int ret; |
218 | |
219 | ec_dev = devm_kzalloc(dev, size: sizeof(*ec_dev), GFP_KERNEL); |
220 | if (!ec_dev) |
221 | return -ENOMEM; |
222 | |
223 | ec_rpmsg = devm_kzalloc(dev, size: sizeof(*ec_rpmsg), GFP_KERNEL); |
224 | if (!ec_rpmsg) |
225 | return -ENOMEM; |
226 | |
227 | ec_dev->dev = dev; |
228 | ec_dev->priv = ec_rpmsg; |
229 | ec_dev->cmd_xfer = cros_ec_cmd_xfer_rpmsg; |
230 | ec_dev->pkt_xfer = cros_ec_pkt_xfer_rpmsg; |
231 | ec_dev->phys_name = dev_name(dev: &rpdev->dev); |
232 | ec_dev->din_size = sizeof(struct ec_host_response) + |
233 | sizeof(struct ec_response_get_protocol_info); |
234 | ec_dev->dout_size = sizeof(struct ec_host_request); |
235 | dev_set_drvdata(dev, data: ec_dev); |
236 | |
237 | ec_rpmsg->rpdev = rpdev; |
238 | init_completion(x: &ec_rpmsg->xfer_ack); |
239 | INIT_WORK(&ec_rpmsg->host_event_work, |
240 | cros_ec_rpmsg_host_event_function); |
241 | |
242 | ec_rpmsg->ept = cros_ec_rpmsg_create_ept(rpdev); |
243 | if (!ec_rpmsg->ept) |
244 | return -ENOMEM; |
245 | |
246 | ret = cros_ec_register(ec_dev); |
247 | if (ret < 0) { |
248 | rpmsg_destroy_ept(ec_rpmsg->ept); |
249 | cancel_work_sync(work: &ec_rpmsg->host_event_work); |
250 | return ret; |
251 | } |
252 | |
253 | ec_rpmsg->probe_done = true; |
254 | |
255 | if (ec_rpmsg->has_pending_host_event) |
256 | schedule_work(work: &ec_rpmsg->host_event_work); |
257 | |
258 | return 0; |
259 | } |
260 | |
261 | static void cros_ec_rpmsg_remove(struct rpmsg_device *rpdev) |
262 | { |
263 | struct cros_ec_device *ec_dev = dev_get_drvdata(dev: &rpdev->dev); |
264 | struct cros_ec_rpmsg *ec_rpmsg = ec_dev->priv; |
265 | |
266 | cros_ec_unregister(ec_dev); |
267 | rpmsg_destroy_ept(ec_rpmsg->ept); |
268 | cancel_work_sync(work: &ec_rpmsg->host_event_work); |
269 | } |
270 | |
271 | #ifdef CONFIG_PM_SLEEP |
272 | static int cros_ec_rpmsg_suspend(struct device *dev) |
273 | { |
274 | struct cros_ec_device *ec_dev = dev_get_drvdata(dev); |
275 | |
276 | return cros_ec_suspend(ec_dev); |
277 | } |
278 | |
279 | static int cros_ec_rpmsg_resume(struct device *dev) |
280 | { |
281 | struct cros_ec_device *ec_dev = dev_get_drvdata(dev); |
282 | |
283 | return cros_ec_resume(ec_dev); |
284 | } |
285 | #endif |
286 | |
287 | static SIMPLE_DEV_PM_OPS(cros_ec_rpmsg_pm_ops, cros_ec_rpmsg_suspend, |
288 | cros_ec_rpmsg_resume); |
289 | |
290 | static const struct of_device_id cros_ec_rpmsg_of_match[] = { |
291 | { .compatible = "google,cros-ec-rpmsg" , }, |
292 | { } |
293 | }; |
294 | MODULE_DEVICE_TABLE(of, cros_ec_rpmsg_of_match); |
295 | |
296 | static struct rpmsg_driver cros_ec_driver_rpmsg = { |
297 | .drv = { |
298 | .name = "cros-ec-rpmsg" , |
299 | .of_match_table = cros_ec_rpmsg_of_match, |
300 | .pm = &cros_ec_rpmsg_pm_ops, |
301 | }, |
302 | .probe = cros_ec_rpmsg_probe, |
303 | .remove = cros_ec_rpmsg_remove, |
304 | }; |
305 | |
306 | module_rpmsg_driver(cros_ec_driver_rpmsg); |
307 | |
308 | MODULE_LICENSE("GPL v2" ); |
309 | MODULE_DESCRIPTION("ChromeOS EC multi function device (rpmsg)" ); |
310 | |