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