1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
5 * Copyright (C) 2014 Google, Inc.
9 #include <linux/mfd/core.h>
10 #include <linux/module.h>
11 #include <linux/mod_devicetable.h>
12 #include <linux/of_platform.h>
13 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16 #include <linux/uaccess.h>
18 #include "cros_ec_dev.h"
20 #define DRV_NAME "cros-ec-dev"
22 /* Device variables */
23 #define CROS_MAX_DEV 128
26 static struct class cros_class = {
31 /* Basic communication */
32 static int ec_get_version(struct cros_ec_dev *ec, char *str, int maxlen)
34 struct ec_response_get_version *resp;
35 static const char * const current_image_name[] = {
36 "unknown", "read-only", "read-write", "invalid",
38 struct cros_ec_command *msg;
41 msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
46 msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
47 msg->insize = sizeof(*resp);
50 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
54 if (msg->result != EC_RES_SUCCESS) {
56 "%s\nUnknown EC version: EC returned %d\n",
57 CROS_EC_DEV_VERSION, msg->result);
62 resp = (struct ec_response_get_version *)msg->data;
63 if (resp->current_image >= ARRAY_SIZE(current_image_name))
64 resp->current_image = 3; /* invalid */
66 snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION,
67 resp->version_string_ro, resp->version_string_rw,
68 current_image_name[resp->current_image]);
76 static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
78 struct cros_ec_command *msg;
81 if (ec->features[0] == -1U && ec->features[1] == -1U) {
82 /* features bitmap not read yet */
84 msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
89 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
90 msg->insize = sizeof(ec->features);
93 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
94 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
95 dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
97 memset(ec->features, 0, sizeof(ec->features));
99 memcpy(ec->features, msg->data, sizeof(ec->features));
102 dev_dbg(ec->dev, "EC features %08x %08x\n",
103 ec->features[0], ec->features[1]);
108 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
111 /* Device file ops */
112 static int ec_device_open(struct inode *inode, struct file *filp)
114 struct cros_ec_dev *ec = container_of(inode->i_cdev,
115 struct cros_ec_dev, cdev);
116 filp->private_data = ec;
117 nonseekable_open(inode, filp);
121 static int ec_device_release(struct inode *inode, struct file *filp)
126 static ssize_t ec_device_read(struct file *filp, char __user *buffer,
127 size_t length, loff_t *offset)
129 struct cros_ec_dev *ec = filp->private_data;
130 char msg[sizeof(struct ec_response_get_version) +
131 sizeof(CROS_EC_DEV_VERSION)];
138 ret = ec_get_version(ec, msg, sizeof(msg));
142 count = min(length, strlen(msg));
144 if (copy_to_user(buffer, msg, count))
152 static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
155 struct cros_ec_command u_cmd;
156 struct cros_ec_command *s_cmd;
158 if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
161 if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
162 (u_cmd.insize > EC_MAX_MSG_BYTES))
165 s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
170 if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
175 if (u_cmd.outsize != s_cmd->outsize ||
176 u_cmd.insize != s_cmd->insize) {
181 s_cmd->command += ec->cmd_offset;
182 ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
183 /* Only copy data to userland if data was received. */
187 if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
194 static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
196 struct cros_ec_device *ec_dev = ec->ec_dev;
197 struct cros_ec_readmem s_mem = { };
200 /* Not every platform supports direct reads */
201 if (!ec_dev->cmd_readmem)
204 if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
207 num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
212 if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
218 static long ec_device_ioctl(struct file *filp, unsigned int cmd,
221 struct cros_ec_dev *ec = filp->private_data;
223 if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
227 case CROS_EC_DEV_IOCXCMD:
228 return ec_device_ioctl_xcmd(ec, (void __user *)arg);
229 case CROS_EC_DEV_IOCRDMEM:
230 return ec_device_ioctl_readmem(ec, (void __user *)arg);
236 /* Module initialization */
237 static const struct file_operations fops = {
238 .open = ec_device_open,
239 .release = ec_device_release,
240 .read = ec_device_read,
241 .unlocked_ioctl = ec_device_ioctl,
243 .compat_ioctl = ec_device_ioctl,
247 static void cros_ec_class_release(struct device *dev)
249 kfree(to_cros_ec_dev(dev));
252 static void cros_ec_sensors_register(struct cros_ec_dev *ec)
255 * Issue a command to get the number of sensor reported.
256 * Build an array of sensors driver and register them all.
258 int ret, i, id, sensor_num;
259 struct mfd_cell *sensor_cells;
260 struct cros_ec_sensor_platform *sensor_platforms;
261 int sensor_type[MOTIONSENSE_TYPE_MAX];
262 struct ec_params_motion_sense *params;
263 struct ec_response_motion_sense *resp;
264 struct cros_ec_command *msg;
266 msg = kzalloc(sizeof(struct cros_ec_command) +
267 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
272 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
273 msg->outsize = sizeof(*params);
274 msg->insize = sizeof(*resp);
276 params = (struct ec_params_motion_sense *)msg->data;
277 params->cmd = MOTIONSENSE_CMD_DUMP;
279 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
280 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
281 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
286 resp = (struct ec_response_motion_sense *)msg->data;
287 sensor_num = resp->dump.sensor_count;
288 /* Allocate 1 extra sensors in FIFO are needed */
289 sensor_cells = kcalloc(sensor_num + 1, sizeof(struct mfd_cell),
291 if (sensor_cells == NULL)
294 sensor_platforms = kcalloc(sensor_num + 1,
295 sizeof(struct cros_ec_sensor_platform),
297 if (sensor_platforms == NULL)
298 goto error_platforms;
300 memset(sensor_type, 0, sizeof(sensor_type));
302 for (i = 0; i < sensor_num; i++) {
303 params->cmd = MOTIONSENSE_CMD_INFO;
304 params->info.sensor_num = i;
305 ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
306 if (ret < 0 || msg->result != EC_RES_SUCCESS) {
307 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
308 i, ret, msg->result);
311 switch (resp->info.type) {
312 case MOTIONSENSE_TYPE_ACCEL:
313 sensor_cells[id].name = "cros-ec-accel";
315 case MOTIONSENSE_TYPE_BARO:
316 sensor_cells[id].name = "cros-ec-baro";
318 case MOTIONSENSE_TYPE_GYRO:
319 sensor_cells[id].name = "cros-ec-gyro";
321 case MOTIONSENSE_TYPE_MAG:
322 sensor_cells[id].name = "cros-ec-mag";
324 case MOTIONSENSE_TYPE_PROX:
325 sensor_cells[id].name = "cros-ec-prox";
327 case MOTIONSENSE_TYPE_LIGHT:
328 sensor_cells[id].name = "cros-ec-light";
330 case MOTIONSENSE_TYPE_ACTIVITY:
331 sensor_cells[id].name = "cros-ec-activity";
334 dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
337 sensor_platforms[id].sensor_num = i;
338 sensor_cells[id].id = sensor_type[resp->info.type];
339 sensor_cells[id].platform_data = &sensor_platforms[id];
340 sensor_cells[id].pdata_size =
341 sizeof(struct cros_ec_sensor_platform);
343 sensor_type[resp->info.type]++;
347 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
348 ec->has_kb_wake_angle = true;
350 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
351 sensor_cells[id].name = "cros-ec-ring";
355 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
358 dev_err(ec->dev, "failed to add EC sensors\n");
360 kfree(sensor_platforms);
367 static const struct mfd_cell cros_ec_cec_cells[] = {
368 { .name = "cros-ec-cec" }
371 static const struct mfd_cell cros_ec_rtc_cells[] = {
372 { .name = "cros-ec-rtc" }
375 static const struct mfd_cell cros_usbpd_charger_cells[] = {
376 { .name = "cros-usbpd-charger" },
377 { .name = "cros-usbpd-logger" },
380 static const struct mfd_cell cros_ec_platform_cells[] = {
381 { .name = "cros-ec-debugfs" },
382 { .name = "cros-ec-lightbar" },
383 { .name = "cros-ec-sysfs" },
386 static const struct mfd_cell cros_ec_vbc_cells[] = {
387 { .name = "cros-ec-vbc" }
390 static int ec_device_probe(struct platform_device *pdev)
392 int retval = -ENOMEM;
393 struct device_node *node;
394 struct device *dev = &pdev->dev;
395 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
396 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
401 dev_set_drvdata(dev, ec);
402 ec->ec_dev = dev_get_drvdata(dev->parent);
404 ec->cmd_offset = ec_platform->cmd_offset;
405 ec->features[0] = -1U; /* Not cached yet */
406 ec->features[1] = -1U; /* Not cached yet */
407 device_initialize(&ec->class_dev);
408 cdev_init(&ec->cdev, &fops);
410 /* Check whether this is actually a Fingerprint MCU rather than an EC */
411 if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) {
412 dev_info(dev, "CrOS Fingerprint MCU detected.\n");
414 * Help userspace differentiating ECs from FP MCU,
415 * regardless of the probing order.
417 ec_platform->ec_name = CROS_EC_DEV_FP_NAME;
421 * Check whether this is actually an Integrated Sensor Hub (ISH)
424 if (cros_ec_check_features(ec, EC_FEATURE_ISH)) {
425 dev_info(dev, "CrOS ISH MCU detected.\n");
427 * Help userspace differentiating ECs from ISH MCU,
428 * regardless of the probing order.
430 ec_platform->ec_name = CROS_EC_DEV_ISH_NAME;
433 /* Check whether this is actually a Touchpad MCU rather than an EC */
434 if (cros_ec_check_features(ec, EC_FEATURE_TOUCHPAD)) {
435 dev_info(dev, "CrOS Touchpad MCU detected.\n");
437 * Help userspace differentiating ECs from TP MCU,
438 * regardless of the probing order.
440 ec_platform->ec_name = CROS_EC_DEV_TP_NAME;
444 * Add the class device
445 * Link to the character device for creating the /dev entry
448 ec->class_dev.devt = MKDEV(ec_major, pdev->id);
449 ec->class_dev.class = &cros_class;
450 ec->class_dev.parent = dev;
451 ec->class_dev.release = cros_ec_class_release;
453 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
455 dev_err(dev, "dev_set_name failed => %d\n", retval);
459 /* check whether this EC is a sensor hub. */
460 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
461 cros_ec_sensors_register(ec);
463 /* Check whether this EC instance has CEC host command support */
464 if (cros_ec_check_features(ec, EC_FEATURE_CEC)) {
465 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
467 ARRAY_SIZE(cros_ec_cec_cells),
471 "failed to add cros-ec-cec device: %d\n",
475 /* Check whether this EC instance has RTC host command support */
476 if (cros_ec_check_features(ec, EC_FEATURE_RTC)) {
477 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
479 ARRAY_SIZE(cros_ec_rtc_cells),
483 "failed to add cros-ec-rtc device: %d\n",
487 /* Check whether this EC instance has the PD charge manager */
488 if (cros_ec_check_features(ec, EC_FEATURE_USB_PD)) {
489 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
490 cros_usbpd_charger_cells,
491 ARRAY_SIZE(cros_usbpd_charger_cells),
495 "failed to add cros-usbpd-charger device: %d\n",
499 /* We can now add the sysfs class, we know which parameter to show */
500 retval = cdev_device_add(&ec->cdev, &ec->class_dev);
502 dev_err(dev, "cdev_device_add failed => %d\n", retval);
506 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
507 cros_ec_platform_cells,
508 ARRAY_SIZE(cros_ec_platform_cells),
512 "failed to add cros-ec platform devices: %d\n",
515 /* Check whether this EC instance has a VBC NVRAM */
516 node = ec->ec_dev->dev->of_node;
517 if (of_property_read_bool(node, "google,has-vbc-nvram")) {
518 retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
520 ARRAY_SIZE(cros_ec_vbc_cells),
523 dev_warn(ec->dev, "failed to add VBC devices: %d\n",
530 put_device(&ec->class_dev);
534 static int ec_device_remove(struct platform_device *pdev)
536 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
538 mfd_remove_devices(ec->dev);
540 device_unregister(&ec->class_dev);
544 static const struct platform_device_id cros_ec_id[] = {
548 MODULE_DEVICE_TABLE(platform, cros_ec_id);
550 static struct platform_driver cros_ec_dev_driver = {
554 .id_table = cros_ec_id,
555 .probe = ec_device_probe,
556 .remove = ec_device_remove,
559 static int __init cros_ec_dev_init(void)
564 ret = class_register(&cros_class);
566 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
570 /* Get a range of minor numbers (starting with 0) to work with */
571 ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
573 pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
574 goto failed_chrdevreg;
576 ec_major = MAJOR(dev);
578 /* Register the driver */
579 ret = platform_driver_register(&cros_ec_dev_driver);
581 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
587 unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
589 class_unregister(&cros_class);
593 static void __exit cros_ec_dev_exit(void)
595 platform_driver_unregister(&cros_ec_dev_driver);
596 unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
597 class_unregister(&cros_class);
600 module_init(cros_ec_dev_init);
601 module_exit(cros_ec_dev_exit);
603 MODULE_ALIAS("platform:" DRV_NAME);
604 MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
605 MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
606 MODULE_VERSION("1.0");
607 MODULE_LICENSE("GPL");