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