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1/*
2 * ChromeOS EC communication protocol helper functions
3 *
4 * Copyright (C) 2015 Google, Inc
5 *
6 * This software is licensed under the terms of the GNU General Public
7 * License version 2, as published by the Free Software Foundation, and
8 * may be copied, distributed, and modified under those terms.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 */
16
17#include <linux/mfd/cros_ec.h>
18#include <linux/delay.h>
19#include <linux/device.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22
23#define EC_COMMAND_RETRIES 50
24
25static int prepare_packet(struct cros_ec_device *ec_dev,
26 struct cros_ec_command *msg)
27{
28 struct ec_host_request *request;
29 u8 *out;
30 int i;
31 u8 csum = 0;
32
33 BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
34 BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
35
36 out = ec_dev->dout;
37 request = (struct ec_host_request *)out;
38 request->struct_version = EC_HOST_REQUEST_VERSION;
39 request->checksum = 0;
40 request->command = msg->command;
41 request->command_version = msg->version;
42 request->reserved = 0;
43 request->data_len = msg->outsize;
44
45 for (i = 0; i < sizeof(*request); i++)
46 csum += out[i];
47
48 /* Copy data and update checksum */
49 memcpy(out + sizeof(*request), msg->data, msg->outsize);
50 for (i = 0; i < msg->outsize; i++)
51 csum += msg->data[i];
52
53 request->checksum = -csum;
54
55 return sizeof(*request) + msg->outsize;
56}
57
58static int send_command(struct cros_ec_device *ec_dev,
59 struct cros_ec_command *msg)
60{
61 int ret;
62
63 if (ec_dev->proto_version > 2)
64 ret = ec_dev->pkt_xfer(ec_dev, msg);
65 else
66 ret = ec_dev->cmd_xfer(ec_dev, msg);
67
68 if (msg->result == EC_RES_IN_PROGRESS) {
69 int i;
70 struct cros_ec_command *status_msg;
71 struct ec_response_get_comms_status *status;
72
73 status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
74 GFP_KERNEL);
75 if (!status_msg)
76 return -ENOMEM;
77
78 status_msg->version = 0;
79 status_msg->command = EC_CMD_GET_COMMS_STATUS;
80 status_msg->insize = sizeof(*status);
81 status_msg->outsize = 0;
82
83 /*
84 * Query the EC's status until it's no longer busy or
85 * we encounter an error.
86 */
87 for (i = 0; i < EC_COMMAND_RETRIES; i++) {
88 usleep_range(10000, 11000);
89
90 ret = ec_dev->cmd_xfer(ec_dev, status_msg);
91 if (ret < 0)
92 break;
93
94 msg->result = status_msg->result;
95 if (status_msg->result != EC_RES_SUCCESS)
96 break;
97
98 status = (struct ec_response_get_comms_status *)
99 status_msg->data;
100 if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
101 break;
102 }
103
104 kfree(status_msg);
105 }
106
107 return ret;
108}
109
110int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
111 struct cros_ec_command *msg)
112{
113 u8 *out;
114 u8 csum;
115 int i;
116
117 if (ec_dev->proto_version > 2)
118 return prepare_packet(ec_dev, msg);
119
120 BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
121 out = ec_dev->dout;
122 out[0] = EC_CMD_VERSION0 + msg->version;
123 out[1] = msg->command;
124 out[2] = msg->outsize;
125 csum = out[0] + out[1] + out[2];
126 for (i = 0; i < msg->outsize; i++)
127 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
128 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
129
130 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
131}
132EXPORT_SYMBOL(cros_ec_prepare_tx);
133
134int cros_ec_check_result(struct cros_ec_device *ec_dev,
135 struct cros_ec_command *msg)
136{
137 switch (msg->result) {
138 case EC_RES_SUCCESS:
139 return 0;
140 case EC_RES_IN_PROGRESS:
141 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
142 msg->command);
143 return -EAGAIN;
144 default:
145 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
146 msg->command, msg->result);
147 return 0;
148 }
149}
150EXPORT_SYMBOL(cros_ec_check_result);
151
152static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
153 int devidx,
154 struct cros_ec_command *msg)
155{
156 /*
157 * Try using v3+ to query for supported protocols. If this
158 * command fails, fall back to v2. Returns the highest protocol
159 * supported by the EC.
160 * Also sets the max request/response/passthru size.
161 */
162 int ret;
163
164 if (!ec_dev->pkt_xfer)
165 return -EPROTONOSUPPORT;
166
167 memset(msg, 0, sizeof(*msg));
168 msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
169 msg->insize = sizeof(struct ec_response_get_protocol_info);
170
171 ret = send_command(ec_dev, msg);
172
173 if (ret < 0) {
174 dev_dbg(ec_dev->dev,
175 "failed to check for EC[%d] protocol version: %d\n",
176 devidx, ret);
177 return ret;
178 }
179
180 if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
181 return -ENODEV;
182 else if (msg->result != EC_RES_SUCCESS)
183 return msg->result;
184
185 return 0;
186}
187
188static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
189{
190 struct cros_ec_command *msg;
191 struct ec_params_hello *hello_params;
192 struct ec_response_hello *hello_response;
193 int ret;
194 int len = max(sizeof(*hello_params), sizeof(*hello_response));
195
196 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
197 if (!msg)
198 return -ENOMEM;
199
200 msg->version = 0;
201 msg->command = EC_CMD_HELLO;
202 hello_params = (struct ec_params_hello *)msg->data;
203 msg->outsize = sizeof(*hello_params);
204 hello_response = (struct ec_response_hello *)msg->data;
205 msg->insize = sizeof(*hello_response);
206
207 hello_params->in_data = 0xa0b0c0d0;
208
209 ret = send_command(ec_dev, msg);
210
211 if (ret < 0) {
212 dev_dbg(ec_dev->dev,
213 "EC failed to respond to v2 hello: %d\n",
214 ret);
215 goto exit;
216 } else if (msg->result != EC_RES_SUCCESS) {
217 dev_err(ec_dev->dev,
218 "EC responded to v2 hello with error: %d\n",
219 msg->result);
220 ret = msg->result;
221 goto exit;
222 } else if (hello_response->out_data != 0xa1b2c3d4) {
223 dev_err(ec_dev->dev,
224 "EC responded to v2 hello with bad result: %u\n",
225 hello_response->out_data);
226 ret = -EBADMSG;
227 goto exit;
228 }
229
230 ret = 0;
231
232 exit:
233 kfree(msg);
234 return ret;
235}
236
237int cros_ec_query_all(struct cros_ec_device *ec_dev)
238{
239 struct device *dev = ec_dev->dev;
240 struct cros_ec_command *proto_msg;
241 struct ec_response_get_protocol_info *proto_info;
242 int ret;
243
244 proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
245 GFP_KERNEL);
246 if (!proto_msg)
247 return -ENOMEM;
248
249 /* First try sending with proto v3. */
250 ec_dev->proto_version = 3;
251 ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);
252
253 if (ret == 0) {
254 proto_info = (struct ec_response_get_protocol_info *)
255 proto_msg->data;
256 ec_dev->max_request = proto_info->max_request_packet_size -
257 sizeof(struct ec_host_request);
258 ec_dev->max_response = proto_info->max_response_packet_size -
259 sizeof(struct ec_host_response);
260 ec_dev->proto_version =
261 min(EC_HOST_REQUEST_VERSION,
262 fls(proto_info->protocol_versions) - 1);
263 dev_dbg(ec_dev->dev,
264 "using proto v%u\n",
265 ec_dev->proto_version);
266
267 ec_dev->din_size = ec_dev->max_response +
268 sizeof(struct ec_host_response) +
269 EC_MAX_RESPONSE_OVERHEAD;
270 ec_dev->dout_size = ec_dev->max_request +
271 sizeof(struct ec_host_request) +
272 EC_MAX_REQUEST_OVERHEAD;
273
274 /*
275 * Check for PD
276 */
277 ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);
278
279 if (ret) {
280 dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
281 ec_dev->max_passthru = 0;
282 } else {
283 dev_dbg(ec_dev->dev, "found PD chip\n");
284 ec_dev->max_passthru =
285 proto_info->max_request_packet_size -
286 sizeof(struct ec_host_request);
287 }
288 } else {
289 /* Try querying with a v2 hello message. */
290 ec_dev->proto_version = 2;
291 ret = cros_ec_host_command_proto_query_v2(ec_dev);
292
293 if (ret == 0) {
294 /* V2 hello succeeded. */
295 dev_dbg(ec_dev->dev, "falling back to proto v2\n");
296
297 ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
298 ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
299 ec_dev->max_passthru = 0;
300 ec_dev->pkt_xfer = NULL;
301 ec_dev->din_size = EC_MSG_BYTES;
302 ec_dev->dout_size = EC_MSG_BYTES;
303 } else {
304 /*
305 * It's possible for a test to occur too early when
306 * the EC isn't listening. If this happens, we'll
307 * test later when the first command is run.
308 */
309 ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
310 dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
311 goto exit;
312 }
313 }
314
315 devm_kfree(dev, ec_dev->din);
316 devm_kfree(dev, ec_dev->dout);
317
318 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
319 if (!ec_dev->din) {
320 ret = -ENOMEM;
321 goto exit;
322 }
323
324 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
325 if (!ec_dev->dout) {
326 devm_kfree(dev, ec_dev->din);
327 ret = -ENOMEM;
328 goto exit;
329 }
330
331exit:
332 kfree(proto_msg);
333 return ret;
334}
335EXPORT_SYMBOL(cros_ec_query_all);
336
337int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
338 struct cros_ec_command *msg)
339{
340 int ret;
341
342 mutex_lock(&ec_dev->lock);
343 if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
344 ret = cros_ec_query_all(ec_dev);
345 if (ret) {
346 dev_err(ec_dev->dev,
347 "EC version unknown and query failed; aborting command\n");
348 mutex_unlock(&ec_dev->lock);
349 return ret;
350 }
351 }
352
353 if (msg->insize > ec_dev->max_response) {
354 dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
355 msg->insize = ec_dev->max_response;
356 }
357
358 if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
359 if (msg->outsize > ec_dev->max_request) {
360 dev_err(ec_dev->dev,
361 "request of size %u is too big (max: %u)\n",
362 msg->outsize,
363 ec_dev->max_request);
364 mutex_unlock(&ec_dev->lock);
365 return -EMSGSIZE;
366 }
367 } else {
368 if (msg->outsize > ec_dev->max_passthru) {
369 dev_err(ec_dev->dev,
370 "passthru rq of size %u is too big (max: %u)\n",
371 msg->outsize,
372 ec_dev->max_passthru);
373 mutex_unlock(&ec_dev->lock);
374 return -EMSGSIZE;
375 }
376 }
377 ret = send_command(ec_dev, msg);
378 mutex_unlock(&ec_dev->lock);
379
380 return ret;
381}
382EXPORT_SYMBOL(cros_ec_cmd_xfer);
1// SPDX-License-Identifier: GPL-2.0
2// ChromeOS EC communication protocol helper functions
3//
4// Copyright (C) 2015 Google, Inc
5
6#include <linux/delay.h>
7#include <linux/device.h>
8#include <linux/module.h>
9#include <linux/platform_data/cros_ec_commands.h>
10#include <linux/platform_data/cros_ec_proto.h>
11#include <linux/slab.h>
12#include <asm/unaligned.h>
13
14#include "cros_ec_trace.h"
15
16#define EC_COMMAND_RETRIES 50
17
18static const int cros_ec_error_map[] = {
19 [EC_RES_INVALID_COMMAND] = -EOPNOTSUPP,
20 [EC_RES_ERROR] = -EIO,
21 [EC_RES_INVALID_PARAM] = -EINVAL,
22 [EC_RES_ACCESS_DENIED] = -EACCES,
23 [EC_RES_INVALID_RESPONSE] = -EPROTO,
24 [EC_RES_INVALID_VERSION] = -ENOPROTOOPT,
25 [EC_RES_INVALID_CHECKSUM] = -EBADMSG,
26 [EC_RES_IN_PROGRESS] = -EINPROGRESS,
27 [EC_RES_UNAVAILABLE] = -ENODATA,
28 [EC_RES_TIMEOUT] = -ETIMEDOUT,
29 [EC_RES_OVERFLOW] = -EOVERFLOW,
30 [EC_RES_INVALID_HEADER] = -EBADR,
31 [EC_RES_REQUEST_TRUNCATED] = -EBADR,
32 [EC_RES_RESPONSE_TOO_BIG] = -EFBIG,
33 [EC_RES_BUS_ERROR] = -EFAULT,
34 [EC_RES_BUSY] = -EBUSY,
35 [EC_RES_INVALID_HEADER_VERSION] = -EBADMSG,
36 [EC_RES_INVALID_HEADER_CRC] = -EBADMSG,
37 [EC_RES_INVALID_DATA_CRC] = -EBADMSG,
38 [EC_RES_DUP_UNAVAILABLE] = -ENODATA,
39};
40
41static int cros_ec_map_error(uint32_t result)
42{
43 int ret = 0;
44
45 if (result != EC_RES_SUCCESS) {
46 if (result < ARRAY_SIZE(cros_ec_error_map) && cros_ec_error_map[result])
47 ret = cros_ec_error_map[result];
48 else
49 ret = -EPROTO;
50 }
51
52 return ret;
53}
54
55static int prepare_packet(struct cros_ec_device *ec_dev,
56 struct cros_ec_command *msg)
57{
58 struct ec_host_request *request;
59 u8 *out;
60 int i;
61 u8 csum = 0;
62
63 BUG_ON(ec_dev->proto_version != EC_HOST_REQUEST_VERSION);
64 BUG_ON(msg->outsize + sizeof(*request) > ec_dev->dout_size);
65
66 out = ec_dev->dout;
67 request = (struct ec_host_request *)out;
68 request->struct_version = EC_HOST_REQUEST_VERSION;
69 request->checksum = 0;
70 request->command = msg->command;
71 request->command_version = msg->version;
72 request->reserved = 0;
73 request->data_len = msg->outsize;
74
75 for (i = 0; i < sizeof(*request); i++)
76 csum += out[i];
77
78 /* Copy data and update checksum */
79 memcpy(out + sizeof(*request), msg->data, msg->outsize);
80 for (i = 0; i < msg->outsize; i++)
81 csum += msg->data[i];
82
83 request->checksum = -csum;
84
85 return sizeof(*request) + msg->outsize;
86}
87
88static int send_command(struct cros_ec_device *ec_dev,
89 struct cros_ec_command *msg)
90{
91 int ret;
92 int (*xfer_fxn)(struct cros_ec_device *ec, struct cros_ec_command *msg);
93
94 if (ec_dev->proto_version > 2)
95 xfer_fxn = ec_dev->pkt_xfer;
96 else
97 xfer_fxn = ec_dev->cmd_xfer;
98
99 if (!xfer_fxn) {
100 /*
101 * This error can happen if a communication error happened and
102 * the EC is trying to use protocol v2, on an underlying
103 * communication mechanism that does not support v2.
104 */
105 dev_err_once(ec_dev->dev,
106 "missing EC transfer API, cannot send command\n");
107 return -EIO;
108 }
109
110 trace_cros_ec_request_start(msg);
111 ret = (*xfer_fxn)(ec_dev, msg);
112 trace_cros_ec_request_done(msg, ret);
113 if (msg->result == EC_RES_IN_PROGRESS) {
114 int i;
115 struct cros_ec_command *status_msg;
116 struct ec_response_get_comms_status *status;
117
118 status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
119 GFP_KERNEL);
120 if (!status_msg)
121 return -ENOMEM;
122
123 status_msg->version = 0;
124 status_msg->command = EC_CMD_GET_COMMS_STATUS;
125 status_msg->insize = sizeof(*status);
126 status_msg->outsize = 0;
127
128 /*
129 * Query the EC's status until it's no longer busy or
130 * we encounter an error.
131 */
132 for (i = 0; i < EC_COMMAND_RETRIES; i++) {
133 usleep_range(10000, 11000);
134
135 trace_cros_ec_request_start(status_msg);
136 ret = (*xfer_fxn)(ec_dev, status_msg);
137 trace_cros_ec_request_done(status_msg, ret);
138 if (ret == -EAGAIN)
139 continue;
140 if (ret < 0)
141 break;
142
143 msg->result = status_msg->result;
144 if (status_msg->result != EC_RES_SUCCESS)
145 break;
146
147 status = (struct ec_response_get_comms_status *)
148 status_msg->data;
149 if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
150 break;
151 }
152
153 kfree(status_msg);
154 }
155
156 return ret;
157}
158
159/**
160 * cros_ec_prepare_tx() - Prepare an outgoing message in the output buffer.
161 * @ec_dev: Device to register.
162 * @msg: Message to write.
163 *
164 * This is intended to be used by all ChromeOS EC drivers, but at present
165 * only SPI uses it. Once LPC uses the same protocol it can start using it.
166 * I2C could use it now, with a refactor of the existing code.
167 *
168 * Return: 0 on success or negative error code.
169 */
170int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
171 struct cros_ec_command *msg)
172{
173 u8 *out;
174 u8 csum;
175 int i;
176
177 if (ec_dev->proto_version > 2)
178 return prepare_packet(ec_dev, msg);
179
180 BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
181 out = ec_dev->dout;
182 out[0] = EC_CMD_VERSION0 + msg->version;
183 out[1] = msg->command;
184 out[2] = msg->outsize;
185 csum = out[0] + out[1] + out[2];
186 for (i = 0; i < msg->outsize; i++)
187 csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
188 out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = csum;
189
190 return EC_MSG_TX_PROTO_BYTES + msg->outsize;
191}
192EXPORT_SYMBOL(cros_ec_prepare_tx);
193
194/**
195 * cros_ec_check_result() - Check ec_msg->result.
196 * @ec_dev: EC device.
197 * @msg: Message to check.
198 *
199 * This is used by ChromeOS EC drivers to check the ec_msg->result for
200 * errors and to warn about them.
201 *
202 * Return: 0 on success or negative error code.
203 */
204int cros_ec_check_result(struct cros_ec_device *ec_dev,
205 struct cros_ec_command *msg)
206{
207 switch (msg->result) {
208 case EC_RES_SUCCESS:
209 return 0;
210 case EC_RES_IN_PROGRESS:
211 dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
212 msg->command);
213 return -EAGAIN;
214 default:
215 dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
216 msg->command, msg->result);
217 return 0;
218 }
219}
220EXPORT_SYMBOL(cros_ec_check_result);
221
222/*
223 * cros_ec_get_host_event_wake_mask
224 *
225 * Get the mask of host events that cause wake from suspend.
226 *
227 * @ec_dev: EC device to call
228 * @msg: message structure to use
229 * @mask: result when function returns >=0.
230 *
231 * LOCKING:
232 * the caller has ec_dev->lock mutex, or the caller knows there is
233 * no other command in progress.
234 */
235static int cros_ec_get_host_event_wake_mask(struct cros_ec_device *ec_dev,
236 struct cros_ec_command *msg,
237 uint32_t *mask)
238{
239 struct ec_response_host_event_mask *r;
240 int ret;
241
242 msg->command = EC_CMD_HOST_EVENT_GET_WAKE_MASK;
243 msg->version = 0;
244 msg->outsize = 0;
245 msg->insize = sizeof(*r);
246
247 ret = send_command(ec_dev, msg);
248 if (ret >= 0) {
249 if (msg->result == EC_RES_INVALID_COMMAND)
250 return -EOPNOTSUPP;
251 if (msg->result != EC_RES_SUCCESS)
252 return -EPROTO;
253 }
254 if (ret > 0) {
255 r = (struct ec_response_host_event_mask *)msg->data;
256 *mask = r->mask;
257 }
258
259 return ret;
260}
261
262static int cros_ec_host_command_proto_query(struct cros_ec_device *ec_dev,
263 int devidx,
264 struct cros_ec_command *msg)
265{
266 /*
267 * Try using v3+ to query for supported protocols. If this
268 * command fails, fall back to v2. Returns the highest protocol
269 * supported by the EC.
270 * Also sets the max request/response/passthru size.
271 */
272 int ret;
273
274 if (!ec_dev->pkt_xfer)
275 return -EPROTONOSUPPORT;
276
277 memset(msg, 0, sizeof(*msg));
278 msg->command = EC_CMD_PASSTHRU_OFFSET(devidx) | EC_CMD_GET_PROTOCOL_INFO;
279 msg->insize = sizeof(struct ec_response_get_protocol_info);
280
281 ret = send_command(ec_dev, msg);
282 /*
283 * Send command once again when timeout occurred.
284 * Fingerprint MCU (FPMCU) is restarted during system boot which
285 * introduces small window in which FPMCU won't respond for any
286 * messages sent by kernel. There is no need to wait before next
287 * attempt because we waited at least EC_MSG_DEADLINE_MS.
288 */
289 if (ret == -ETIMEDOUT)
290 ret = send_command(ec_dev, msg);
291
292 if (ret < 0) {
293 dev_dbg(ec_dev->dev,
294 "failed to check for EC[%d] protocol version: %d\n",
295 devidx, ret);
296 return ret;
297 }
298
299 if (devidx > 0 && msg->result == EC_RES_INVALID_COMMAND)
300 return -ENODEV;
301 else if (msg->result != EC_RES_SUCCESS)
302 return msg->result;
303
304 return 0;
305}
306
307static int cros_ec_host_command_proto_query_v2(struct cros_ec_device *ec_dev)
308{
309 struct cros_ec_command *msg;
310 struct ec_params_hello *hello_params;
311 struct ec_response_hello *hello_response;
312 int ret;
313 int len = max(sizeof(*hello_params), sizeof(*hello_response));
314
315 msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
316 if (!msg)
317 return -ENOMEM;
318
319 msg->version = 0;
320 msg->command = EC_CMD_HELLO;
321 hello_params = (struct ec_params_hello *)msg->data;
322 msg->outsize = sizeof(*hello_params);
323 hello_response = (struct ec_response_hello *)msg->data;
324 msg->insize = sizeof(*hello_response);
325
326 hello_params->in_data = 0xa0b0c0d0;
327
328 ret = send_command(ec_dev, msg);
329
330 if (ret < 0) {
331 dev_dbg(ec_dev->dev,
332 "EC failed to respond to v2 hello: %d\n",
333 ret);
334 goto exit;
335 } else if (msg->result != EC_RES_SUCCESS) {
336 dev_err(ec_dev->dev,
337 "EC responded to v2 hello with error: %d\n",
338 msg->result);
339 ret = msg->result;
340 goto exit;
341 } else if (hello_response->out_data != 0xa1b2c3d4) {
342 dev_err(ec_dev->dev,
343 "EC responded to v2 hello with bad result: %u\n",
344 hello_response->out_data);
345 ret = -EBADMSG;
346 goto exit;
347 }
348
349 ret = 0;
350
351 exit:
352 kfree(msg);
353 return ret;
354}
355
356/*
357 * cros_ec_get_host_command_version_mask
358 *
359 * Get the version mask of a given command.
360 *
361 * @ec_dev: EC device to call
362 * @msg: message structure to use
363 * @cmd: command to get the version of.
364 * @mask: result when function returns 0.
365 *
366 * @return 0 on success, error code otherwise
367 *
368 * LOCKING:
369 * the caller has ec_dev->lock mutex or the caller knows there is
370 * no other command in progress.
371 */
372static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev,
373 u16 cmd, u32 *mask)
374{
375 struct ec_params_get_cmd_versions *pver;
376 struct ec_response_get_cmd_versions *rver;
377 struct cros_ec_command *msg;
378 int ret;
379
380 msg = kmalloc(sizeof(*msg) + max(sizeof(*rver), sizeof(*pver)),
381 GFP_KERNEL);
382 if (!msg)
383 return -ENOMEM;
384
385 msg->version = 0;
386 msg->command = EC_CMD_GET_CMD_VERSIONS;
387 msg->insize = sizeof(*rver);
388 msg->outsize = sizeof(*pver);
389
390 pver = (struct ec_params_get_cmd_versions *)msg->data;
391 pver->cmd = cmd;
392
393 ret = send_command(ec_dev, msg);
394 if (ret > 0) {
395 rver = (struct ec_response_get_cmd_versions *)msg->data;
396 *mask = rver->version_mask;
397 }
398
399 kfree(msg);
400
401 return ret;
402}
403
404/**
405 * cros_ec_query_all() - Query the protocol version supported by the
406 * ChromeOS EC.
407 * @ec_dev: Device to register.
408 *
409 * Return: 0 on success or negative error code.
410 */
411int cros_ec_query_all(struct cros_ec_device *ec_dev)
412{
413 struct device *dev = ec_dev->dev;
414 struct cros_ec_command *proto_msg;
415 struct ec_response_get_protocol_info *proto_info;
416 u32 ver_mask = 0;
417 int ret;
418
419 proto_msg = kzalloc(sizeof(*proto_msg) + sizeof(*proto_info),
420 GFP_KERNEL);
421 if (!proto_msg)
422 return -ENOMEM;
423
424 /* First try sending with proto v3. */
425 ec_dev->proto_version = 3;
426 ret = cros_ec_host_command_proto_query(ec_dev, 0, proto_msg);
427
428 if (ret == 0) {
429 proto_info = (struct ec_response_get_protocol_info *)
430 proto_msg->data;
431 ec_dev->max_request = proto_info->max_request_packet_size -
432 sizeof(struct ec_host_request);
433 ec_dev->max_response = proto_info->max_response_packet_size -
434 sizeof(struct ec_host_response);
435 ec_dev->proto_version =
436 min(EC_HOST_REQUEST_VERSION,
437 fls(proto_info->protocol_versions) - 1);
438 dev_dbg(ec_dev->dev,
439 "using proto v%u\n",
440 ec_dev->proto_version);
441
442 ec_dev->din_size = ec_dev->max_response +
443 sizeof(struct ec_host_response) +
444 EC_MAX_RESPONSE_OVERHEAD;
445 ec_dev->dout_size = ec_dev->max_request +
446 sizeof(struct ec_host_request) +
447 EC_MAX_REQUEST_OVERHEAD;
448
449 /*
450 * Check for PD
451 */
452 ret = cros_ec_host_command_proto_query(ec_dev, 1, proto_msg);
453
454 if (ret) {
455 dev_dbg(ec_dev->dev, "no PD chip found: %d\n", ret);
456 ec_dev->max_passthru = 0;
457 } else {
458 dev_dbg(ec_dev->dev, "found PD chip\n");
459 ec_dev->max_passthru =
460 proto_info->max_request_packet_size -
461 sizeof(struct ec_host_request);
462 }
463 } else {
464 /* Try querying with a v2 hello message. */
465 ec_dev->proto_version = 2;
466 ret = cros_ec_host_command_proto_query_v2(ec_dev);
467
468 if (ret == 0) {
469 /* V2 hello succeeded. */
470 dev_dbg(ec_dev->dev, "falling back to proto v2\n");
471
472 ec_dev->max_request = EC_PROTO2_MAX_PARAM_SIZE;
473 ec_dev->max_response = EC_PROTO2_MAX_PARAM_SIZE;
474 ec_dev->max_passthru = 0;
475 ec_dev->pkt_xfer = NULL;
476 ec_dev->din_size = EC_PROTO2_MSG_BYTES;
477 ec_dev->dout_size = EC_PROTO2_MSG_BYTES;
478 } else {
479 /*
480 * It's possible for a test to occur too early when
481 * the EC isn't listening. If this happens, we'll
482 * test later when the first command is run.
483 */
484 ec_dev->proto_version = EC_PROTO_VERSION_UNKNOWN;
485 dev_dbg(ec_dev->dev, "EC query failed: %d\n", ret);
486 goto exit;
487 }
488 }
489
490 devm_kfree(dev, ec_dev->din);
491 devm_kfree(dev, ec_dev->dout);
492
493 ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
494 if (!ec_dev->din) {
495 ret = -ENOMEM;
496 goto exit;
497 }
498
499 ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
500 if (!ec_dev->dout) {
501 devm_kfree(dev, ec_dev->din);
502 ret = -ENOMEM;
503 goto exit;
504 }
505
506 /* Probe if MKBP event is supported */
507 ret = cros_ec_get_host_command_version_mask(ec_dev,
508 EC_CMD_GET_NEXT_EVENT,
509 &ver_mask);
510 if (ret < 0 || ver_mask == 0)
511 ec_dev->mkbp_event_supported = 0;
512 else
513 ec_dev->mkbp_event_supported = fls(ver_mask);
514
515 dev_dbg(ec_dev->dev, "MKBP support version %u\n",
516 ec_dev->mkbp_event_supported - 1);
517
518 /* Probe if host sleep v1 is supported for S0ix failure detection. */
519 ret = cros_ec_get_host_command_version_mask(ec_dev,
520 EC_CMD_HOST_SLEEP_EVENT,
521 &ver_mask);
522 ec_dev->host_sleep_v1 = (ret >= 0 && (ver_mask & EC_VER_MASK(1)));
523
524 /* Get host event wake mask. */
525 ret = cros_ec_get_host_event_wake_mask(ec_dev, proto_msg,
526 &ec_dev->host_event_wake_mask);
527 if (ret < 0) {
528 /*
529 * If the EC doesn't support EC_CMD_HOST_EVENT_GET_WAKE_MASK,
530 * use a reasonable default. Note that we ignore various
531 * battery, AC status, and power-state events, because (a)
532 * those can be quite common (e.g., when sitting at full
533 * charge, on AC) and (b) these are not actionable wake events;
534 * if anything, we'd like to continue suspending (to save
535 * power), not wake up.
536 */
537 ec_dev->host_event_wake_mask = U32_MAX &
538 ~(EC_HOST_EVENT_MASK(EC_HOST_EVENT_LID_CLOSED) |
539 EC_HOST_EVENT_MASK(EC_HOST_EVENT_AC_DISCONNECTED) |
540 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_LOW) |
541 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_CRITICAL) |
542 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY) |
543 EC_HOST_EVENT_MASK(EC_HOST_EVENT_PD_MCU) |
544 EC_HOST_EVENT_MASK(EC_HOST_EVENT_BATTERY_STATUS));
545 /*
546 * Old ECs may not support this command. Complain about all
547 * other errors.
548 */
549 if (ret != -EOPNOTSUPP)
550 dev_err(ec_dev->dev,
551 "failed to retrieve wake mask: %d\n", ret);
552 }
553
554 ret = 0;
555
556exit:
557 kfree(proto_msg);
558 return ret;
559}
560EXPORT_SYMBOL(cros_ec_query_all);
561
562/**
563 * cros_ec_cmd_xfer_status() - Send a command to the ChromeOS EC.
564 * @ec_dev: EC device.
565 * @msg: Message to write.
566 *
567 * Call this to send a command to the ChromeOS EC. This should be used instead of calling the EC's
568 * cmd_xfer() callback directly. It returns success status only if both the command was transmitted
569 * successfully and the EC replied with success status.
570 *
571 * Return:
572 * >=0 - The number of bytes transferred
573 * <0 - Linux error code
574 */
575int cros_ec_cmd_xfer_status(struct cros_ec_device *ec_dev,
576 struct cros_ec_command *msg)
577{
578 int ret, mapped;
579
580 mutex_lock(&ec_dev->lock);
581 if (ec_dev->proto_version == EC_PROTO_VERSION_UNKNOWN) {
582 ret = cros_ec_query_all(ec_dev);
583 if (ret) {
584 dev_err(ec_dev->dev,
585 "EC version unknown and query failed; aborting command\n");
586 mutex_unlock(&ec_dev->lock);
587 return ret;
588 }
589 }
590
591 if (msg->insize > ec_dev->max_response) {
592 dev_dbg(ec_dev->dev, "clamping message receive buffer\n");
593 msg->insize = ec_dev->max_response;
594 }
595
596 if (msg->command < EC_CMD_PASSTHRU_OFFSET(1)) {
597 if (msg->outsize > ec_dev->max_request) {
598 dev_err(ec_dev->dev,
599 "request of size %u is too big (max: %u)\n",
600 msg->outsize,
601 ec_dev->max_request);
602 mutex_unlock(&ec_dev->lock);
603 return -EMSGSIZE;
604 }
605 } else {
606 if (msg->outsize > ec_dev->max_passthru) {
607 dev_err(ec_dev->dev,
608 "passthru rq of size %u is too big (max: %u)\n",
609 msg->outsize,
610 ec_dev->max_passthru);
611 mutex_unlock(&ec_dev->lock);
612 return -EMSGSIZE;
613 }
614 }
615
616 ret = send_command(ec_dev, msg);
617 mutex_unlock(&ec_dev->lock);
618
619 mapped = cros_ec_map_error(msg->result);
620 if (mapped) {
621 dev_dbg(ec_dev->dev, "Command result (err: %d [%d])\n",
622 msg->result, mapped);
623 ret = mapped;
624 }
625
626 return ret;
627}
628EXPORT_SYMBOL(cros_ec_cmd_xfer_status);
629
630static int get_next_event_xfer(struct cros_ec_device *ec_dev,
631 struct cros_ec_command *msg,
632 struct ec_response_get_next_event_v1 *event,
633 int version, uint32_t size)
634{
635 int ret;
636
637 msg->version = version;
638 msg->command = EC_CMD_GET_NEXT_EVENT;
639 msg->insize = size;
640 msg->outsize = 0;
641
642 ret = cros_ec_cmd_xfer_status(ec_dev, msg);
643 if (ret > 0) {
644 ec_dev->event_size = ret - 1;
645 ec_dev->event_data = *event;
646 }
647
648 return ret;
649}
650
651static int get_next_event(struct cros_ec_device *ec_dev)
652{
653 struct {
654 struct cros_ec_command msg;
655 struct ec_response_get_next_event_v1 event;
656 } __packed buf;
657 struct cros_ec_command *msg = &buf.msg;
658 struct ec_response_get_next_event_v1 *event = &buf.event;
659 const int cmd_version = ec_dev->mkbp_event_supported - 1;
660
661 memset(msg, 0, sizeof(*msg));
662 if (ec_dev->suspended) {
663 dev_dbg(ec_dev->dev, "Device suspended.\n");
664 return -EHOSTDOWN;
665 }
666
667 if (cmd_version == 0)
668 return get_next_event_xfer(ec_dev, msg, event, 0,
669 sizeof(struct ec_response_get_next_event));
670
671 return get_next_event_xfer(ec_dev, msg, event, cmd_version,
672 sizeof(struct ec_response_get_next_event_v1));
673}
674
675static int get_keyboard_state_event(struct cros_ec_device *ec_dev)
676{
677 u8 buffer[sizeof(struct cros_ec_command) +
678 sizeof(ec_dev->event_data.data)];
679 struct cros_ec_command *msg = (struct cros_ec_command *)&buffer;
680
681 msg->version = 0;
682 msg->command = EC_CMD_MKBP_STATE;
683 msg->insize = sizeof(ec_dev->event_data.data);
684 msg->outsize = 0;
685
686 ec_dev->event_size = cros_ec_cmd_xfer_status(ec_dev, msg);
687 ec_dev->event_data.event_type = EC_MKBP_EVENT_KEY_MATRIX;
688 memcpy(&ec_dev->event_data.data, msg->data,
689 sizeof(ec_dev->event_data.data));
690
691 return ec_dev->event_size;
692}
693
694/**
695 * cros_ec_get_next_event() - Fetch next event from the ChromeOS EC.
696 * @ec_dev: Device to fetch event from.
697 * @wake_event: Pointer to a bool set to true upon return if the event might be
698 * treated as a wake event. Ignored if null.
699 * @has_more_events: Pointer to bool set to true if more than one event is
700 * pending.
701 * Some EC will set this flag to indicate cros_ec_get_next_event()
702 * can be called multiple times in a row.
703 * It is an optimization to prevent issuing a EC command for
704 * nothing or wait for another interrupt from the EC to process
705 * the next message.
706 * Ignored if null.
707 *
708 * Return: negative error code on errors; 0 for no data; or else number of
709 * bytes received (i.e., an event was retrieved successfully). Event types are
710 * written out to @ec_dev->event_data.event_type on success.
711 */
712int cros_ec_get_next_event(struct cros_ec_device *ec_dev,
713 bool *wake_event,
714 bool *has_more_events)
715{
716 u8 event_type;
717 u32 host_event;
718 int ret;
719
720 /*
721 * Default value for wake_event.
722 * Wake up on keyboard event, wake up for spurious interrupt or link
723 * error to the EC.
724 */
725 if (wake_event)
726 *wake_event = true;
727
728 /*
729 * Default value for has_more_events.
730 * EC will raise another interrupt if AP does not process all events
731 * anyway.
732 */
733 if (has_more_events)
734 *has_more_events = false;
735
736 if (!ec_dev->mkbp_event_supported)
737 return get_keyboard_state_event(ec_dev);
738
739 ret = get_next_event(ec_dev);
740 if (ret <= 0)
741 return ret;
742
743 if (has_more_events)
744 *has_more_events = ec_dev->event_data.event_type &
745 EC_MKBP_HAS_MORE_EVENTS;
746 ec_dev->event_data.event_type &= EC_MKBP_EVENT_TYPE_MASK;
747
748 if (wake_event) {
749 event_type = ec_dev->event_data.event_type;
750 host_event = cros_ec_get_host_event(ec_dev);
751
752 /*
753 * Sensor events need to be parsed by the sensor sub-device.
754 * Defer them, and don't report the wakeup here.
755 */
756 if (event_type == EC_MKBP_EVENT_SENSOR_FIFO) {
757 *wake_event = false;
758 } else if (host_event) {
759 /* rtc_update_irq() already handles wakeup events. */
760 if (host_event & EC_HOST_EVENT_MASK(EC_HOST_EVENT_RTC))
761 *wake_event = false;
762 /* Masked host-events should not count as wake events. */
763 if (!(host_event & ec_dev->host_event_wake_mask))
764 *wake_event = false;
765 }
766 }
767
768 return ret;
769}
770EXPORT_SYMBOL(cros_ec_get_next_event);
771
772/**
773 * cros_ec_get_host_event() - Return a mask of event set by the ChromeOS EC.
774 * @ec_dev: Device to fetch event from.
775 *
776 * When MKBP is supported, when the EC raises an interrupt, we collect the
777 * events raised and call the functions in the ec notifier. This function
778 * is a helper to know which events are raised.
779 *
780 * Return: 0 on error or non-zero bitmask of one or more EC_HOST_EVENT_*.
781 */
782u32 cros_ec_get_host_event(struct cros_ec_device *ec_dev)
783{
784 u32 host_event;
785
786 BUG_ON(!ec_dev->mkbp_event_supported);
787
788 if (ec_dev->event_data.event_type != EC_MKBP_EVENT_HOST_EVENT)
789 return 0;
790
791 if (ec_dev->event_size != sizeof(host_event)) {
792 dev_warn(ec_dev->dev, "Invalid host event size\n");
793 return 0;
794 }
795
796 host_event = get_unaligned_le32(&ec_dev->event_data.data.host_event);
797
798 return host_event;
799}
800EXPORT_SYMBOL(cros_ec_get_host_event);
801
802/**
803 * cros_ec_check_features() - Test for the presence of EC features
804 *
805 * @ec: EC device, does not have to be connected directly to the AP,
806 * can be daisy chained through another device.
807 * @feature: One of ec_feature_code bit.
808 *
809 * Call this function to test whether the ChromeOS EC supports a feature.
810 *
811 * Return: 1 if supported, 0 if not
812 */
813int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
814{
815 struct cros_ec_command *msg;
816 int ret;
817
818 if (ec->features[0] == -1U && ec->features[1] == -1U) {
819 /* features bitmap not read yet */
820 msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
821 if (!msg)
822 return -ENOMEM;
823
824 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
825 msg->insize = sizeof(ec->features);
826
827 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
828 if (ret < 0) {
829 dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
830 ret, msg->result);
831 memset(ec->features, 0, sizeof(ec->features));
832 } else {
833 memcpy(ec->features, msg->data, sizeof(ec->features));
834 }
835
836 dev_dbg(ec->dev, "EC features %08x %08x\n",
837 ec->features[0], ec->features[1]);
838
839 kfree(msg);
840 }
841
842 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
843}
844EXPORT_SYMBOL_GPL(cros_ec_check_features);
845
846/**
847 * cros_ec_get_sensor_count() - Return the number of MEMS sensors supported.
848 *
849 * @ec: EC device, does not have to be connected directly to the AP,
850 * can be daisy chained through another device.
851 * Return: < 0 in case of error.
852 */
853int cros_ec_get_sensor_count(struct cros_ec_dev *ec)
854{
855 /*
856 * Issue a command to get the number of sensor reported.
857 * If not supported, check for legacy mode.
858 */
859 int ret, sensor_count;
860 struct ec_params_motion_sense *params;
861 struct ec_response_motion_sense *resp;
862 struct cros_ec_command *msg;
863 struct cros_ec_device *ec_dev = ec->ec_dev;
864 u8 status;
865
866 msg = kzalloc(sizeof(*msg) + max(sizeof(*params), sizeof(*resp)),
867 GFP_KERNEL);
868 if (!msg)
869 return -ENOMEM;
870
871 msg->version = 1;
872 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
873 msg->outsize = sizeof(*params);
874 msg->insize = sizeof(*resp);
875
876 params = (struct ec_params_motion_sense *)msg->data;
877 params->cmd = MOTIONSENSE_CMD_DUMP;
878
879 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
880 if (ret < 0) {
881 sensor_count = ret;
882 } else {
883 resp = (struct ec_response_motion_sense *)msg->data;
884 sensor_count = resp->dump.sensor_count;
885 }
886 kfree(msg);
887
888 /*
889 * Check legacy mode: Let's find out if sensors are accessible
890 * via LPC interface.
891 */
892 if (sensor_count < 0 && ec->cmd_offset == 0 && ec_dev->cmd_readmem) {
893 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS,
894 1, &status);
895 if (ret >= 0 &&
896 (status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
897 /*
898 * We have 2 sensors, one in the lid, one in the base.
899 */
900 sensor_count = 2;
901 } else {
902 /*
903 * EC uses LPC interface and no sensors are presented.
904 */
905 sensor_count = 0;
906 }
907 }
908 return sensor_count;
909}
910EXPORT_SYMBOL_GPL(cros_ec_get_sensor_count);