2 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
4 * Copyright (C) 2014 Google, Inc.
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.
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.
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/>.
21 #include <linux/mfd/core.h>
22 #include <linux/module.h>
23 #include <linux/mod_devicetable.h>
24 #include <linux/platform_device.h>
26 #include <linux/slab.h>
27 #include <linux/uaccess.h>
29 #include "cros_ec_dev.h"
31 #define DRV_NAME "cros-ec-dev"
33 /* Device variables */
34 #define CROS_MAX_DEV 128
37 static const struct attribute_group *cros_ec_groups[] = {
39 &cros_ec_lightbar_attr_group,
40 &cros_ec_vbc_attr_group,
44 static struct class cros_class = {
47 .dev_groups = cros_ec_groups,
50 /* Basic communication */
51 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
53 struct ec_response_get_version *resp;
54 static const char * const current_image_name[] = {
55 "unknown", "read-only", "read-write", "invalid",
57 struct cros_ec_command *msg;
60 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
65 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
66 msg->insize = sizeof(*resp);
69 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
73 if (msg->result != EC_RES_SUCCESS) {
75 "%s\nUnknown EC version: EC returned %d\n",
76 CROS_EC_DEV_VERSION, msg->result);
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 */
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]);
95 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
97 struct cros_ec_command *msg;
100 if (ec->features[0] == -1U && ec->features[1] == -1U) {
101 /* features bitmap not read yet */
103 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
108 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
109 msg->insize = sizeof(ec->features);
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",
116 memset(ec->features, 0, sizeof(ec->features));
118 memcpy(ec->features, msg->data, sizeof(ec->features));
121 dev_dbg(ec->dev, "EC features %08x %08x\n",
122 ec->features[0], ec->features[1]);
127 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
130 /* Device file ops */
131 static int ec_device_open(struct inode *inode, struct file *filp)
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);
140 static int ec_device_release(struct inode *inode, struct file *filp)
145 static ssize_t ec_device_read(struct file *filp, char __user *buffer,
146 size_t length, loff_t *offset)
148 struct cros_ec_dev *ec = filp->private_data;
149 char msg[sizeof(struct ec_response_get_version) +
150 sizeof(CROS_EC_DEV_VERSION)];
157 ret = ec_get_version(ec, msg, sizeof(msg));
161 count = min(length, strlen(msg));
163 if (copy_to_user(buffer, msg, count))
171 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
174 struct cros_ec_command u_cmd;
175 struct cros_ec_command *s_cmd;
177 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
180 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
181 (u_cmd.insize > EC_MAX_MSG_BYTES))
184 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
189 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
194 if (u_cmd.outsize != s_cmd->outsize ||
195 u_cmd.insize != s_cmd->insize) {
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. */
206 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
213 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
215 struct cros_ec_device *ec_dev = ec->ec_dev;
216 struct cros_ec_readmem s_mem = { };
219 /* Not every platform supports direct reads */
220 if (!ec_dev->cmd_readmem)
223 if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
226 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
231 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
237 static long ec_device_ioctl(struct file *filp, unsigned int cmd,
240 struct cros_ec_dev *ec = filp->private_data;
242 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
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);
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,
262 .compat_ioctl = ec_device_ioctl,
266 static void cros_ec_class_release(struct device *dev)
268 kfree(to_cros_ec_dev(dev));
271 static void cros_ec_sensors_register(struct cros_ec_dev *ec)
274 * Issue a command to get the number of sensor reported.
275 * Build an array of sensors driver and register them all.
277 int ret, i, id, sensor_num;
278 struct mfd_cell *sensor_cells;
279 struct cros_ec_sensor_platform *sensor_platforms;
280 int sensor_type[MOTIONSENSE_TYPE_MAX];
281 struct ec_params_motion_sense *params;
282 struct ec_response_motion_sense *resp;
283 struct cros_ec_command *msg;
285 msg = kzalloc(sizeof(struct cros_ec_command) +
286 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
291 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
292 msg->outsize = sizeof(*params);
293 msg->insize = sizeof(*resp);
295 params = (struct ec_params_motion_sense *)msg->data;
296 params->cmd = MOTIONSENSE_CMD_DUMP;
298 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
299 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
300 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
305 resp = (struct ec_response_motion_sense *)msg->data;
306 sensor_num = resp->dump.sensor_count;
307 /* Allocate 1 extra sensors in FIFO are needed */
308 sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
310 if (sensor_cells == NULL)
313 sensor_platforms = kcalloc(sensor_num + 1,
314 sizeof(struct cros_ec_sensor_platform),
316 if (sensor_platforms == NULL)
317 goto error_platforms;
319 memset(sensor_type, 0, sizeof(sensor_type));
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);
330 switch (resp->info.type) {
331 case MOTIONSENSE_TYPE_ACCEL:
332 sensor_cells[id].name = "cros-ec-accel";
334 case MOTIONSENSE_TYPE_BARO:
335 sensor_cells[id].name = "cros-ec-baro";
337 case MOTIONSENSE_TYPE_GYRO:
338 sensor_cells[id].name = "cros-ec-gyro";
340 case MOTIONSENSE_TYPE_MAG:
341 sensor_cells[id].name = "cros-ec-mag";
343 case MOTIONSENSE_TYPE_PROX:
344 sensor_cells[id].name = "cros-ec-prox";
346 case MOTIONSENSE_TYPE_LIGHT:
347 sensor_cells[id].name = "cros-ec-light";
349 case MOTIONSENSE_TYPE_ACTIVITY:
350 sensor_cells[id].name = "cros-ec-activity";
353 dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
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);
362 sensor_type[resp->info.type]++;
366 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
367 ec->has_kb_wake_angle = true;
369 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
370 sensor_cells[id].name = "cros-ec-ring";
374 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
377 dev_err(ec->dev, "failed to add EC sensors\n");
379 kfree(sensor_platforms);
386 static const struct mfd_cell cros_ec_cec_cells[] = {
387 { .name = "cros-ec-cec" }
390 static const struct mfd_cell cros_ec_rtc_cells[] = {
391 { .name = "cros-ec-rtc" }
394 static const struct mfd_cell cros_usbpd_charger_cells[] = {
395 { .name = "cros-usbpd-charger" }
398 static int ec_device_probe(struct platform_device *pdev)
400 int retval = -ENOMEM;
401 struct device *dev = &pdev->dev;
402 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
403 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
408 dev_set_drvdata(dev, ec);
409 ec->ec_dev = dev_get_drvdata(dev->parent);
411 ec->cmd_offset = ec_platform->cmd_offset;
412 ec->features[0] = -1U; /* Not cached yet */
413 ec->features[1] = -1U; /* Not cached yet */
414 device_initialize(&ec->class_dev);
415 cdev_init(&ec->cdev, &fops);
418 * Add the class device
419 * Link to the character device for creating the /dev entry
422 ec->class_dev.devt = MKDEV(ec_major, pdev->id);
423 ec->class_dev.class = &cros_class;
424 ec->class_dev.parent = dev;
425 ec->class_dev.release = cros_ec_class_release;
427 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
429 dev_err(dev, "dev_set_name failed => %d\n", retval);
433 /* check whether this EC is a sensor hub. */
434 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
435 cros_ec_sensors_register(ec);
437 /* Check whether this EC instance has CEC host command support */
438 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
439 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
441 ARRAY_SIZE(cros_ec_cec_cells),
445 "failed to add cros-ec-cec device: %d\n",
449 /* Check whether this EC instance has RTC host command support */
450 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
451 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
453 ARRAY_SIZE(cros_ec_rtc_cells),
457 "failed to add cros-ec-rtc device: %d\n",
461 /* Check whether this EC instance has the PD charge manager */
462 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
463 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
464 cros_usbpd_charger_cells,
465 ARRAY_SIZE(cros_usbpd_charger_cells),
469 "failed to add cros-usbpd-charger device: %d\n",
473 /* Take control of the lightbar from the EC. */
474 lb_manual_suspend_ctrl(ec, 1);
476 /* We can now add the sysfs class, we know which parameter to show */
477 retval = cdev_device_add(&ec->cdev, &ec->class_dev);
479 dev_err(dev, "cdev_device_add failed => %d\n", retval);
483 if (cros_ec_debugfs_init(ec))
484 dev_warn(dev, "failed to create debugfs directory\n");
489 put_device(&ec->class_dev);
493 static int ec_device_remove(struct platform_device *pdev)
495 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
497 /* Let the EC take over the lightbar again. */
498 lb_manual_suspend_ctrl(ec, 0);
500 cros_ec_debugfs_remove(ec);
503 device_unregister(&ec->class_dev);
507 static void ec_device_shutdown(struct platform_device *pdev)
509 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
511 /* Be sure to clear up debugfs delayed works */
512 cros_ec_debugfs_remove(ec);
515 static const struct platform_device_id cros_ec_id[] = {
519 MODULE_DEVICE_TABLE(platform, cros_ec_id);
521 static __maybe_unused int ec_device_suspend(struct device *dev)
523 struct cros_ec_dev *ec = dev_get_drvdata(dev);
525 cros_ec_debugfs_suspend(ec);
532 static __maybe_unused int ec_device_resume(struct device *dev)
534 struct cros_ec_dev *ec = dev_get_drvdata(dev);
536 cros_ec_debugfs_resume(ec);
543 static const struct dev_pm_ops cros_ec_dev_pm_ops = {
544 #ifdef CONFIG_PM_SLEEP
545 .suspend = ec_device_suspend,
546 .resume = ec_device_resume,
550 static struct platform_driver cros_ec_dev_driver = {
553 .pm = &cros_ec_dev_pm_ops,
555 .id_table = cros_ec_id,
556 .probe = ec_device_probe,
557 .remove = ec_device_remove,
558 .shutdown = ec_device_shutdown,
561 static int __init cros_ec_dev_init(void)
566 ret = class_register(&cros_class);
568 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
572 /* Get a range of minor numbers (starting with 0) to work with */
573 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
575 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
576 goto failed_chrdevreg;
578 ec_major = MAJOR(dev);
580 /* Register the driver */
581 ret = platform_driver_register(&cros_ec_dev_driver);
583 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
589 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
591 class_unregister(&cros_class);
595 static void __exit cros_ec_dev_exit(void)
597 platform_driver_unregister(&cros_ec_dev_driver);
598 unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
599 class_unregister(&cros_class);
602 module_init(cros_ec_dev_init);
603 module_exit(cros_ec_dev_exit);
605 MODULE_ALIAS("platform:" DRV_NAME);
606 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
607 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
608 MODULE_VERSION("1.0");
609 MODULE_LICENSE("GPL");