1 /*
2 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
3 *
4 * Copyright (C) 2014 Google, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include <linux/fs.h>
21 #include <linux/mfd/core.h>
22 #include <linux/module.h>
23 #include <linux/mod_devicetable.h>
24 #include <linux/platform_device.h>
25 #include <linux/pm.h>
26 #include <linux/slab.h>
27 #include <linux/uaccess.h>
28
29 #include "cros_ec_dev.h"
30
31 #define DRV_NAME "cros-ec-dev"
32
33 /* Device variables */
34 #define CROS_MAX_DEV 128
35 static int ec_major;
36
37 static const struct attribute_group *cros_ec_groups[] = {
38 &cros_ec_attr_group,
39 &cros_ec_lightbar_attr_group,
40 &cros_ec_vbc_attr_group,
41 NULL,
42 };
43
44 static struct class cros_class = {
45 .owner = THIS_MODULE,
46 .name = "chromeos",
47 .dev_groups = cros_ec_groups,
48 };
49
50 /* Basic communication */
ec_get_version(struct cros_ec_dev * ec,char * str,int maxlen)51 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
52 {
53 struct ec_response_get_version *resp;
54 static const char * const current_image_name[] = {
55 "unknown", "read-only", "read-write", "invalid",
56 };
57 struct cros_ec_command *msg;
58 int ret;
59
60 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
61 if (!msg)
62 return -ENOMEM;
63
64 msg->version = 0;
65 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
66 msg->insize = sizeof(*resp);
67 msg->outsize = 0;
68
69 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
70 if (ret < 0)
71 goto exit;
72
73 if (msg->result != EC_RES_SUCCESS) {
74 snprintf(str, maxlen,
75 "%s\nUnknown EC version: EC returned %d\n",
76 CROS_EC_DEV_VERSION, msg->result);
77 ret = -EINVAL;
78 goto exit;
79 }
80
81 resp = (struct ec_response_get_version *)msg->data;
82 if (resp->current_image >= ARRAY_SIZE(current_image_name))
83 resp->current_image = 3; /* invalid */
84
85 snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION,
86 resp->version_string_ro, resp->version_string_rw,
87 current_image_name[resp->current_image]);
88
89 ret = 0;
90 exit:
91 kfree(msg);
92 return ret;
93 }
94
cros_ec_check_features(struct cros_ec_dev * ec,int feature)95 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
96 {
97 struct cros_ec_command *msg;
98 int ret;
99
100 if (ec->features[0] == -1U && ec->features[1] == -1U) {
101 /* features bitmap not read yet */
102
103 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
104 if (!msg)
105 return -ENOMEM;
106
107 msg->version = 0;
108 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
109 msg->insize = sizeof(ec->features);
110 msg->outsize = 0;
111
112 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
113 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
114 dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
115 ret, msg->result);
116 memset(ec->features, 0, sizeof(ec->features));
117 } else {
118 memcpy(ec->features, msg->data, sizeof(ec->features));
119 }
120
121 dev_dbg(ec->dev, "EC features %08x %08x\n",
122 ec->features[0], ec->features[1]);
123
124 kfree(msg);
125 }
126
127 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
128 }
129
130 /* Device file ops */
ec_device_open(struct inode * inode,struct file * filp)131 static int ec_device_open(struct inode *inode, struct file *filp)
132 {
133 struct cros_ec_dev *ec = container_of(inode->i_cdev,
134 struct cros_ec_dev, cdev);
135 filp->private_data = ec;
136 nonseekable_open(inode, filp);
137 return 0;
138 }
139
ec_device_release(struct inode * inode,struct file * filp)140 static int ec_device_release(struct inode *inode, struct file *filp)
141 {
142 return 0;
143 }
144
ec_device_read(struct file * filp,char __user * buffer,size_t length,loff_t * offset)145 static ssize_t ec_device_read(struct file *filp, char __user *buffer,
146 size_t length, loff_t *offset)
147 {
148 struct cros_ec_dev *ec = filp->private_data;
149 char msg[sizeof(struct ec_response_get_version) +
150 sizeof(CROS_EC_DEV_VERSION)];
151 size_t count;
152 int ret;
153
154 if (*offset != 0)
155 return 0;
156
157 ret = ec_get_version(ec, msg, sizeof(msg));
158 if (ret)
159 return ret;
160
161 count = min(length, strlen(msg));
162
163 if (copy_to_user(buffer, msg, count))
164 return -EFAULT;
165
166 *offset = count;
167 return count;
168 }
169
170 /* Ioctls */
ec_device_ioctl_xcmd(struct cros_ec_dev * ec,void __user * arg)171 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
172 {
173 long ret;
174 struct cros_ec_command u_cmd;
175 struct cros_ec_command *s_cmd;
176
177 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
178 return -EFAULT;
179
180 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
181 (u_cmd.insize > EC_MAX_MSG_BYTES))
182 return -EINVAL;
183
184 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
185 GFP_KERNEL);
186 if (!s_cmd)
187 return -ENOMEM;
188
189 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
190 ret = -EFAULT;
191 goto exit;
192 }
193
194 if (u_cmd.outsize != s_cmd->outsize ||
195 u_cmd.insize != s_cmd->insize) {
196 ret = -EINVAL;
197 goto exit;
198 }
199
200 s_cmd->command += ec->cmd_offset;
201 ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
202 /* Only copy data to userland if data was received. */
203 if (ret < 0)
204 goto exit;
205
206 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
207 ret = -EFAULT;
208 exit:
209 kfree(s_cmd);
210 return ret;
211 }
212
ec_device_ioctl_readmem(struct cros_ec_dev * ec,void __user * arg)213 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
214 {
215 struct cros_ec_device *ec_dev = ec->ec_dev;
216 struct cros_ec_readmem s_mem = { };
217 long num;
218
219 /* Not every platform supports direct reads */
220 if (!ec_dev->cmd_readmem)
221 return -ENOTTY;
222
223 if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
224 return -EFAULT;
225
226 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
227 s_mem.buffer);
228 if (num <= 0)
229 return num;
230
231 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
232 return -EFAULT;
233
234 return 0;
235 }
236
ec_device_ioctl(struct file * filp,unsigned int cmd,unsigned long arg)237 static long ec_device_ioctl(struct file *filp, unsigned int cmd,
238 unsigned long arg)
239 {
240 struct cros_ec_dev *ec = filp->private_data;
241
242 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
243 return -ENOTTY;
244
245 switch (cmd) {
246 case CROS_EC_DEV_IOCXCMD:
247 return ec_device_ioctl_xcmd(ec, (void __user *)arg);
248 case CROS_EC_DEV_IOCRDMEM:
249 return ec_device_ioctl_readmem(ec, (void __user *)arg);
250 }
251
252 return -ENOTTY;
253 }
254
255 /* Module initialization */
256 static const struct file_operations fops = {
257 .open = ec_device_open,
258 .release = ec_device_release,
259 .read = ec_device_read,
260 .unlocked_ioctl = ec_device_ioctl,
261 #ifdef CONFIG_COMPAT
262 .compat_ioctl = ec_device_ioctl,
263 #endif
264 };
265
cros_ec_sensors_register(struct cros_ec_dev * ec)266 static void cros_ec_sensors_register(struct cros_ec_dev *ec)
267 {
268 /*
269 * Issue a command to get the number of sensor reported.
270 * Build an array of sensors driver and register them all.
271 */
272 int ret, i, id, sensor_num;
273 struct mfd_cell *sensor_cells;
274 struct cros_ec_sensor_platform *sensor_platforms;
275 int sensor_type[MOTIONSENSE_TYPE_MAX];
276 struct ec_params_motion_sense *params;
277 struct ec_response_motion_sense *resp;
278 struct cros_ec_command *msg;
279
280 msg = kzalloc(sizeof(struct cros_ec_command) +
281 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
282 if (msg == NULL)
283 return;
284
285 msg->version = 2;
286 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
287 msg->outsize = sizeof(*params);
288 msg->insize = sizeof(*resp);
289
290 params = (struct ec_params_motion_sense *)msg->data;
291 params->cmd = MOTIONSENSE_CMD_DUMP;
292
293 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
294 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
295 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
296 ret, msg->result);
297 goto error;
298 }
299
300 resp = (struct ec_response_motion_sense *)msg->data;
301 sensor_num = resp->dump.sensor_count;
302 /* Allocate 1 extra sensors in FIFO are needed */
303 sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
304 GFP_KERNEL);
305 if (sensor_cells == NULL)
306 goto error;
307
308 sensor_platforms = kcalloc(sensor_num + 1,
309 sizeof(struct cros_ec_sensor_platform),
310 GFP_KERNEL);
311 if (sensor_platforms == NULL)
312 goto error_platforms;
313
314 memset(sensor_type, 0, sizeof(sensor_type));
315 id = 0;
316 for (i = 0; i < sensor_num; i++) {
317 params->cmd = MOTIONSENSE_CMD_INFO;
318 params->info.sensor_num = i;
319 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
320 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
321 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
322 i, ret, msg->result);
323 continue;
324 }
325 switch (resp->info.type) {
326 case MOTIONSENSE_TYPE_ACCEL:
327 sensor_cells[id].name = "cros-ec-accel";
328 break;
329 case MOTIONSENSE_TYPE_BARO:
330 sensor_cells[id].name = "cros-ec-baro";
331 break;
332 case MOTIONSENSE_TYPE_GYRO:
333 sensor_cells[id].name = "cros-ec-gyro";
334 break;
335 case MOTIONSENSE_TYPE_MAG:
336 sensor_cells[id].name = "cros-ec-mag";
337 break;
338 case MOTIONSENSE_TYPE_PROX:
339 sensor_cells[id].name = "cros-ec-prox";
340 break;
341 case MOTIONSENSE_TYPE_LIGHT:
342 sensor_cells[id].name = "cros-ec-light";
343 break;
344 case MOTIONSENSE_TYPE_ACTIVITY:
345 sensor_cells[id].name = "cros-ec-activity";
346 break;
347 default:
348 dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
349 continue;
350 }
351 sensor_platforms[id].sensor_num = i;
352 sensor_cells[id].id = sensor_type[resp->info.type];
353 sensor_cells[id].platform_data = &sensor_platforms[id];
354 sensor_cells[id].pdata_size =
355 sizeof(struct cros_ec_sensor_platform);
356
357 sensor_type[resp->info.type]++;
358 id++;
359 }
360
361 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
362 ec->has_kb_wake_angle = true;
363
364 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
365 sensor_cells[id].name = "cros-ec-ring";
366 id++;
367 }
368
369 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
370 NULL, 0, NULL);
371 if (ret)
372 dev_err(ec->dev, "failed to add EC sensors\n");
373
374 kfree(sensor_platforms);
375 error_platforms:
376 kfree(sensor_cells);
377 error:
378 kfree(msg);
379 }
380
381 static const struct mfd_cell cros_ec_cec_cells[] = {
382 { .name = "cros-ec-cec" }
383 };
384
385 static const struct mfd_cell cros_ec_rtc_cells[] = {
386 { .name = "cros-ec-rtc" }
387 };
388
389 static const struct mfd_cell cros_usbpd_charger_cells[] = {
390 { .name = "cros-usbpd-charger" }
391 };
392
ec_device_probe(struct platform_device * pdev)393 static int ec_device_probe(struct platform_device *pdev)
394 {
395 int retval = -ENOMEM;
396 struct device *dev = &pdev->dev;
397 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
398 struct cros_ec_dev *ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL);
399
400 if (!ec)
401 return retval;
402
403 dev_set_drvdata(dev, ec);
404 ec->ec_dev = dev_get_drvdata(dev->parent);
405 ec->dev = dev;
406 ec->cmd_offset = ec_platform->cmd_offset;
407 ec->features[0] = -1U; /* Not cached yet */
408 ec->features[1] = -1U; /* Not cached yet */
409 device_initialize(&ec->class_dev);
410 cdev_init(&ec->cdev, &fops);
411
412 /*
413 * Add the class device
414 * Link to the character device for creating the /dev entry
415 * in devtmpfs.
416 */
417 ec->class_dev.devt = MKDEV(ec_major, pdev->id);
418 ec->class_dev.class = &cros_class;
419 ec->class_dev.parent = dev;
420
421 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
422 if (retval) {
423 dev_err(dev, "dev_set_name failed => %d\n", retval);
424 goto failed;
425 }
426
427 /* check whether this EC is a sensor hub. */
428 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
429 cros_ec_sensors_register(ec);
430
431 /* Check whether this EC instance has CEC host command support */
432 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
433 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
434 cros_ec_cec_cells,
435 ARRAY_SIZE(cros_ec_cec_cells),
436 NULL, 0, NULL);
437 if (retval)
438 dev_err(ec->dev,
439 "failed to add cros-ec-cec device: %d\n",
440 retval);
441 }
442
443 /* Check whether this EC instance has RTC host command support */
444 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
445 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
446 cros_ec_rtc_cells,
447 ARRAY_SIZE(cros_ec_rtc_cells),
448 NULL, 0, NULL);
449 if (retval)
450 dev_err(ec->dev,
451 "failed to add cros-ec-rtc device: %d\n",
452 retval);
453 }
454
455 /* Check whether this EC instance has the PD charge manager */
456 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
457 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
458 cros_usbpd_charger_cells,
459 ARRAY_SIZE(cros_usbpd_charger_cells),
460 NULL, 0, NULL);
461 if (retval)
462 dev_err(ec->dev,
463 "failed to add cros-usbpd-charger device: %d\n",
464 retval);
465 }
466
467 /* Take control of the lightbar from the EC. */
468 lb_manual_suspend_ctrl(ec, 1);
469
470 /* We can now add the sysfs class, we know which parameter to show */
471 retval = cdev_device_add(&ec->cdev, &ec->class_dev);
472 if (retval) {
473 dev_err(dev, "cdev_device_add failed => %d\n", retval);
474 goto failed;
475 }
476
477 if (cros_ec_debugfs_init(ec))
478 dev_warn(dev, "failed to create debugfs directory\n");
479
480 return 0;
481
482 failed:
483 put_device(&ec->class_dev);
484 return retval;
485 }
486
ec_device_remove(struct platform_device * pdev)487 static int ec_device_remove(struct platform_device *pdev)
488 {
489 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
490
491 /* Let the EC take over the lightbar again. */
492 lb_manual_suspend_ctrl(ec, 0);
493
494 cros_ec_debugfs_remove(ec);
495
496 cdev_del(&ec->cdev);
497 device_unregister(&ec->class_dev);
498 return 0;
499 }
500
ec_device_shutdown(struct platform_device * pdev)501 static void ec_device_shutdown(struct platform_device *pdev)
502 {
503 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
504
505 /* Be sure to clear up debugfs delayed works */
506 cros_ec_debugfs_remove(ec);
507 }
508
509 static const struct platform_device_id cros_ec_id[] = {
510 { DRV_NAME, 0 },
511 { /* sentinel */ }
512 };
513 MODULE_DEVICE_TABLE(platform, cros_ec_id);
514
ec_device_suspend(struct device * dev)515 static __maybe_unused int ec_device_suspend(struct device *dev)
516 {
517 struct cros_ec_dev *ec = dev_get_drvdata(dev);
518
519 cros_ec_debugfs_suspend(ec);
520
521 lb_suspend(ec);
522
523 return 0;
524 }
525
ec_device_resume(struct device * dev)526 static __maybe_unused int ec_device_resume(struct device *dev)
527 {
528 struct cros_ec_dev *ec = dev_get_drvdata(dev);
529
530 cros_ec_debugfs_resume(ec);
531
532 lb_resume(ec);
533
534 return 0;
535 }
536
537 static const struct dev_pm_ops cros_ec_dev_pm_ops = {
538 #ifdef CONFIG_PM_SLEEP
539 .suspend = ec_device_suspend,
540 .resume = ec_device_resume,
541 #endif
542 };
543
544 static struct platform_driver cros_ec_dev_driver = {
545 .driver = {
546 .name = DRV_NAME,
547 .pm = &cros_ec_dev_pm_ops,
548 },
549 .probe = ec_device_probe,
550 .remove = ec_device_remove,
551 .shutdown = ec_device_shutdown,
552 };
553
cros_ec_dev_init(void)554 static int __init cros_ec_dev_init(void)
555 {
556 int ret;
557 dev_t dev = 0;
558
559 ret = class_register(&cros_class);
560 if (ret) {
561 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
562 return ret;
563 }
564
565 /* Get a range of minor numbers (starting with 0) to work with */
566 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
567 if (ret < 0) {
568 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
569 goto failed_chrdevreg;
570 }
571 ec_major = MAJOR(dev);
572
573 /* Register the driver */
574 ret = platform_driver_register(&cros_ec_dev_driver);
575 if (ret < 0) {
576 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
577 goto failed_devreg;
578 }
579 return 0;
580
581 failed_devreg:
582 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
583 failed_chrdevreg:
584 class_unregister(&cros_class);
585 return ret;
586 }
587
cros_ec_dev_exit(void)588 static void __exit cros_ec_dev_exit(void)
589 {
590 platform_driver_unregister(&cros_ec_dev_driver);
591 unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
592 class_unregister(&cros_class);
593 }
594
595 module_init(cros_ec_dev_init);
596 module_exit(cros_ec_dev_exit);
597
598 MODULE_ALIAS("platform:" DRV_NAME);
599 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
600 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
601 MODULE_VERSION("1.0");
602 MODULE_LICENSE("GPL");
603
