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/of_platform.h>
25 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28 #include <linux/uaccess.h>
30 #include "cros_ec_dev.h"
32 #define DRV_NAME "cros-ec-dev"
34 /* Device variables */
35 #define CROS_MAX_DEV 128
38 static struct class cros_class = {
43 /* Basic communication */
44 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
46 struct ec_response_get_version *resp;
47 static const char * const current_image_name[] = {
48 "unknown", "read-only", "read-write", "invalid",
50 struct cros_ec_command *msg;
53 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
58 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
59 msg->insize = sizeof(*resp);
62 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
66 if (msg->result != EC_RES_SUCCESS) {
68 "%s\nUnknown EC version: EC returned %d\n",
69 CROS_EC_DEV_VERSION, msg->result);
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 */
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]);
88 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
90 struct cros_ec_command *msg;
93 if (ec->features[0] == -1U && ec->features[1] == -1U) {
94 /* features bitmap not read yet */
96 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
101 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
102 msg->insize = sizeof(ec->features);
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",
109 memset(ec->features, 0, sizeof(ec->features));
111 memcpy(ec->features, msg->data, sizeof(ec->features));
114 dev_dbg(ec->dev, "EC features %08x %08x\n",
115 ec->features[0], ec->features[1]);
120 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
123 /* Device file ops */
124 static int ec_device_open(struct inode *inode, struct file *filp)
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);
133 static int ec_device_release(struct inode *inode, struct file *filp)
138 static ssize_t ec_device_read(struct file *filp, char __user *buffer,
139 size_t length, loff_t *offset)
141 struct cros_ec_dev *ec = filp->private_data;
142 char msg[sizeof(struct ec_response_get_version) +
143 sizeof(CROS_EC_DEV_VERSION)];
150 ret = ec_get_version(ec, msg, sizeof(msg));
154 count = min(length, strlen(msg));
156 if (copy_to_user(buffer, msg, count))
164 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
167 struct cros_ec_command u_cmd;
168 struct cros_ec_command *s_cmd;
170 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
173 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
174 (u_cmd.insize > EC_MAX_MSG_BYTES))
177 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
182 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
187 if (u_cmd.outsize != s_cmd->outsize ||
188 u_cmd.insize != s_cmd->insize) {
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. */
199 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
206 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
208 struct cros_ec_device *ec_dev = ec->ec_dev;
209 struct cros_ec_readmem s_mem = { };
212 /* Not every platform supports direct reads */
213 if (!ec_dev->cmd_readmem)
216 if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
219 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
224 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
230 static long ec_device_ioctl(struct file *filp, unsigned int cmd,
233 struct cros_ec_dev *ec = filp->private_data;
235 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
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);
248 /* Module initialization */
249 static 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,
255 .compat_ioctl = ec_device_ioctl,
259 static void cros_ec_class_release(struct device *dev)
261 kfree(to_cros_ec_dev(dev));
264 static void cros_ec_sensors_register(struct cros_ec_dev *ec)
267 * Issue a command to get the number of sensor reported.
268 * Build an array of sensors driver and register them all.
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;
278 msg = kzalloc(sizeof(struct cros_ec_command) +
279 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
284 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
285 msg->outsize = sizeof(*params);
286 msg->insize = sizeof(*resp);
288 params = (struct ec_params_motion_sense *)msg->data;
289 params->cmd = MOTIONSENSE_CMD_DUMP;
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",
298 resp = (struct ec_response_motion_sense *)msg->data;
299 sensor_num = resp->dump.sensor_count;
301 * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
303 sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
305 if (sensor_cells == NULL)
308 sensor_platforms = kcalloc(sensor_num,
309 sizeof(struct cros_ec_sensor_platform),
311 if (sensor_platforms == NULL)
312 goto error_platforms;
314 memset(sensor_type, 0, sizeof(sensor_type));
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);
325 switch (resp->info.type) {
326 case MOTIONSENSE_TYPE_ACCEL:
327 sensor_cells[id].name = "cros-ec-accel";
329 case MOTIONSENSE_TYPE_BARO:
330 sensor_cells[id].name = "cros-ec-baro";
332 case MOTIONSENSE_TYPE_GYRO:
333 sensor_cells[id].name = "cros-ec-gyro";
335 case MOTIONSENSE_TYPE_MAG:
336 sensor_cells[id].name = "cros-ec-mag";
338 case MOTIONSENSE_TYPE_PROX:
339 sensor_cells[id].name = "cros-ec-prox";
341 case MOTIONSENSE_TYPE_LIGHT:
342 sensor_cells[id].name = "cros-ec-light";
344 case MOTIONSENSE_TYPE_ACTIVITY:
345 sensor_cells[id].name = "cros-ec-activity";
348 dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
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);
357 sensor_type[resp->info.type]++;
361 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
362 ec->has_kb_wake_angle = true;
364 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
365 sensor_cells[id].name = "cros-ec-ring";
368 if (cros_ec_check_features(ec,
369 EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
370 sensor_cells[id].name = "cros-ec-lid-angle";
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" },
396 { .name = "cros-usbpd-logger" },
399 static const struct mfd_cell cros_ec_platform_cells[] = {
400 { .name = "cros-ec-debugfs" },
401 { .name = "cros-ec-lightbar" },
402 { .name = "cros-ec-sysfs" },
405 static const struct mfd_cell cros_ec_vbc_cells[] = {
406 { .name = "cros-ec-vbc" }
409 static int ec_device_probe(struct platform_device *pdev)
411 int retval = -ENOMEM;
412 struct device_node *node;
413 struct device *dev = &pdev->dev;
414 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
415 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
420 dev_set_drvdata(dev, ec);
421 ec->ec_dev = dev_get_drvdata(dev->parent);
423 ec->cmd_offset = ec_platform->cmd_offset;
424 ec->features[0] = -1U; /* Not cached yet */
425 ec->features[1] = -1U; /* Not cached yet */
426 device_initialize(&ec->class_dev);
427 cdev_init(&ec->cdev, &fops);
429 /* Check whether this is actually a Fingerprint MCU rather than an EC */
430 if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) {
431 dev_info(dev, "CrOS Fingerprint MCU detected.\n");
433 * Help userspace differentiating ECs from FP MCU,
434 * regardless of the probing order.
436 ec_platform->ec_name = CROS_EC_DEV_FP_NAME;
440 * Check whether this is actually an Integrated Sensor Hub (ISH)
443 if (cros_ec_check_features(ec, EC_FEATURE_ISH)) {
444 dev_info(dev, "CrOS ISH MCU detected.\n");
446 * Help userspace differentiating ECs from ISH MCU,
447 * regardless of the probing order.
449 ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
452 /* Check whether this is actually a Touchpad MCU rather than an EC */
453 if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) {
454 dev_info(dev, "CrOS Touchpad MCU detected.\n");
456 * Help userspace differentiating ECs from TP MCU,
457 * regardless of the probing order.
459 ec_platform->ec_name = CROS_EC_DEV_TP_NAME;
462 /* Check whether this is actually a SCP rather than an EC. */
463 if (cros_ec_check_features(ec, EC_FEATURE_SCP)) {
464 dev_info(dev, "CrOS SCP MCU detected.\n");
466 * Help userspace differentiating ECs from SCP,
467 * regardless of the probing order.
469 ec_platform->ec_name = CROS_EC_DEV_SCP_NAME;
473 * Add the class device
474 * Link to the character device for creating the /dev entry
477 ec->class_dev.devt = MKDEV(ec_major, pdev->id);
478 ec->class_dev.class = &cros_class;
479 ec->class_dev.parent = dev;
480 ec->class_dev.release = cros_ec_class_release;
482 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
484 dev_err(dev, "dev_set_name failed => %d\n", retval);
488 /* check whether this EC is a sensor hub. */
489 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
490 cros_ec_sensors_register(ec);
492 /* Check whether this EC instance has CEC host command support */
493 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
494 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
496 ARRAY_SIZE(cros_ec_cec_cells),
500 "failed to add cros-ec-cec device: %d\n",
504 /* Check whether this EC instance has RTC host command support */
505 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
506 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
508 ARRAY_SIZE(cros_ec_rtc_cells),
512 "failed to add cros-ec-rtc device: %d\n",
516 /* Check whether this EC instance has the PD charge manager */
517 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
518 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
519 cros_usbpd_charger_cells,
520 ARRAY_SIZE(cros_usbpd_charger_cells),
524 "failed to add cros-usbpd-charger device: %d\n",
528 /* We can now add the sysfs class, we know which parameter to show */
529 retval = cdev_device_add(&ec->cdev, &ec->class_dev);
531 dev_err(dev, "cdev_device_add failed => %d\n", retval);
535 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
536 cros_ec_platform_cells,
537 ARRAY_SIZE(cros_ec_platform_cells),
541 "failed to add cros-ec platform devices: %d\n",
544 /* Check whether this EC instance has a VBC NVRAM */
545 node = ec->ec_dev->dev->of_node;
546 if (of_property_read_bool(node, "google,has-vbc-nvram")) {
547 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
549 ARRAY_SIZE(cros_ec_vbc_cells),
552 dev_warn(ec->dev, "failed to add VBC devices: %d\n",
559 put_device(&ec->class_dev);
563 static int ec_device_remove(struct platform_device *pdev)
565 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
567 mfd_remove_devices(ec->dev);
569 device_unregister(&ec->class_dev);
573 static const struct platform_device_id cros_ec_id[] = {
577 MODULE_DEVICE_TABLE(platform, cros_ec_id);
579 static struct platform_driver cros_ec_dev_driver = {
583 .id_table = cros_ec_id,
584 .probe = ec_device_probe,
585 .remove = ec_device_remove,
588 static int __init cros_ec_dev_init(void)
593 ret = class_register(&cros_class);
595 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
599 /* Get a range of minor numbers (starting with 0) to work with */
600 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
602 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
603 goto failed_chrdevreg;
605 ec_major = MAJOR(dev);
607 /* Register the driver */
608 ret = platform_driver_register(&cros_ec_dev_driver);
610 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
616 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
618 class_unregister(&cros_class);
622 static void __exit cros_ec_dev_exit(void)
624 platform_driver_unregister(&cros_ec_dev_driver);
625 unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
626 class_unregister(&cros_class);
629 module_init(cros_ec_dev_init);
630 module_exit(cros_ec_dev_exit);
632 MODULE_ALIAS("platform:" DRV_NAME);
633 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
634 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
635 MODULE_VERSION("1.0");
636 MODULE_LICENSE("GPL");