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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
4 *
5 * Copyright (C) 2014 Google, Inc.
6 */
7
8#include <linux/mfd/core.h>
9#include <linux/mfd/cros_ec.h>
10#include <linux/module.h>
11#include <linux/mod_devicetable.h>
12#include <linux/of_platform.h>
13#include <linux/platform_device.h>
14#include <linux/platform_data/cros_ec_chardev.h>
15#include <linux/platform_data/cros_ec_commands.h>
16#include <linux/platform_data/cros_ec_proto.h>
17#include <linux/slab.h>
18
19#define DRV_NAME "cros-ec-dev"
20
21static struct class cros_class = {
22 .owner = THIS_MODULE,
23 .name = "chromeos",
24};
25
26/**
27 * cros_feature_to_name - CrOS feature id to name/short description.
28 * @id: The feature identifier.
29 * @name: Device name associated with the feature id.
30 * @desc: Short name that will be displayed.
31 */
32struct cros_feature_to_name {
33 unsigned int id;
34 const char *name;
35 const char *desc;
36};
37
38/**
39 * cros_feature_to_cells - CrOS feature id to mfd cells association.
40 * @id: The feature identifier.
41 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
42 * @num_cells: Number of mfd cells into the array.
43 */
44struct cros_feature_to_cells {
45 unsigned int id;
46 const struct mfd_cell *mfd_cells;
47 unsigned int num_cells;
48};
49
50static const struct cros_feature_to_name cros_mcu_devices[] = {
51 {
52 .id = EC_FEATURE_FINGERPRINT,
53 .name = CROS_EC_DEV_FP_NAME,
54 .desc = "Fingerprint",
55 },
56 {
57 .id = EC_FEATURE_ISH,
58 .name = CROS_EC_DEV_ISH_NAME,
59 .desc = "Integrated Sensor Hub",
60 },
61 {
62 .id = EC_FEATURE_SCP,
63 .name = CROS_EC_DEV_SCP_NAME,
64 .desc = "System Control Processor",
65 },
66 {
67 .id = EC_FEATURE_TOUCHPAD,
68 .name = CROS_EC_DEV_TP_NAME,
69 .desc = "Touchpad",
70 },
71};
72
73static const struct mfd_cell cros_ec_cec_cells[] = {
74 { .name = "cros-ec-cec", },
75};
76
77static const struct mfd_cell cros_ec_rtc_cells[] = {
78 { .name = "cros-ec-rtc", },
79};
80
81static const struct mfd_cell cros_usbpd_charger_cells[] = {
82 { .name = "cros-usbpd-charger", },
83 { .name = "cros-usbpd-logger", },
84};
85
86static const struct cros_feature_to_cells cros_subdevices[] = {
87 {
88 .id = EC_FEATURE_CEC,
89 .mfd_cells = cros_ec_cec_cells,
90 .num_cells = ARRAY_SIZE(cros_ec_cec_cells),
91 },
92 {
93 .id = EC_FEATURE_RTC,
94 .mfd_cells = cros_ec_rtc_cells,
95 .num_cells = ARRAY_SIZE(cros_ec_rtc_cells),
96 },
97 {
98 .id = EC_FEATURE_USB_PD,
99 .mfd_cells = cros_usbpd_charger_cells,
100 .num_cells = ARRAY_SIZE(cros_usbpd_charger_cells),
101 },
102};
103
104static const struct mfd_cell cros_ec_platform_cells[] = {
105 { .name = "cros-ec-chardev", },
106 { .name = "cros-ec-debugfs", },
107 { .name = "cros-ec-lightbar", },
108 { .name = "cros-ec-sysfs", },
109};
110
111static const struct mfd_cell cros_ec_vbc_cells[] = {
112 { .name = "cros-ec-vbc", }
113};
114
115static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
116{
117 struct cros_ec_command *msg;
118 int ret;
119
120 if (ec->features[0] == -1U && ec->features[1] == -1U) {
121 /* features bitmap not read yet */
122 msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
123 if (!msg)
124 return -ENOMEM;
125
126 msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
127 msg->insize = sizeof(ec->features);
128
129 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
130 if (ret < 0) {
131 dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
132 ret, msg->result);
133 memset(ec->features, 0, sizeof(ec->features));
134 } else {
135 memcpy(ec->features, msg->data, sizeof(ec->features));
136 }
137
138 dev_dbg(ec->dev, "EC features %08x %08x\n",
139 ec->features[0], ec->features[1]);
140
141 kfree(msg);
142 }
143
144 return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
145}
146
147static void cros_ec_class_release(struct device *dev)
148{
149 kfree(to_cros_ec_dev(dev));
150}
151
152static void cros_ec_sensors_register(struct cros_ec_dev *ec)
153{
154 /*
155 * Issue a command to get the number of sensor reported.
156 * Build an array of sensors driver and register them all.
157 */
158 int ret, i, id, sensor_num;
159 struct mfd_cell *sensor_cells;
160 struct cros_ec_sensor_platform *sensor_platforms;
161 int sensor_type[MOTIONSENSE_TYPE_MAX];
162 struct ec_params_motion_sense *params;
163 struct ec_response_motion_sense *resp;
164 struct cros_ec_command *msg;
165
166 msg = kzalloc(sizeof(struct cros_ec_command) +
167 max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
168 if (msg == NULL)
169 return;
170
171 msg->version = 2;
172 msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
173 msg->outsize = sizeof(*params);
174 msg->insize = sizeof(*resp);
175
176 params = (struct ec_params_motion_sense *)msg->data;
177 params->cmd = MOTIONSENSE_CMD_DUMP;
178
179 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
180 if (ret < 0) {
181 dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
182 ret, msg->result);
183 goto error;
184 }
185
186 resp = (struct ec_response_motion_sense *)msg->data;
187 sensor_num = resp->dump.sensor_count;
188 /*
189 * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
190 */
191 sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
192 GFP_KERNEL);
193 if (sensor_cells == NULL)
194 goto error;
195
196 sensor_platforms = kcalloc(sensor_num,
197 sizeof(struct cros_ec_sensor_platform),
198 GFP_KERNEL);
199 if (sensor_platforms == NULL)
200 goto error_platforms;
201
202 memset(sensor_type, 0, sizeof(sensor_type));
203 id = 0;
204 for (i = 0; i < sensor_num; i++) {
205 params->cmd = MOTIONSENSE_CMD_INFO;
206 params->info.sensor_num = i;
207 ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
208 if (ret < 0) {
209 dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
210 i, ret, msg->result);
211 continue;
212 }
213 switch (resp->info.type) {
214 case MOTIONSENSE_TYPE_ACCEL:
215 sensor_cells[id].name = "cros-ec-accel";
216 break;
217 case MOTIONSENSE_TYPE_BARO:
218 sensor_cells[id].name = "cros-ec-baro";
219 break;
220 case MOTIONSENSE_TYPE_GYRO:
221 sensor_cells[id].name = "cros-ec-gyro";
222 break;
223 case MOTIONSENSE_TYPE_MAG:
224 sensor_cells[id].name = "cros-ec-mag";
225 break;
226 case MOTIONSENSE_TYPE_PROX:
227 sensor_cells[id].name = "cros-ec-prox";
228 break;
229 case MOTIONSENSE_TYPE_LIGHT:
230 sensor_cells[id].name = "cros-ec-light";
231 break;
232 case MOTIONSENSE_TYPE_ACTIVITY:
233 sensor_cells[id].name = "cros-ec-activity";
234 break;
235 default:
236 dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
237 continue;
238 }
239 sensor_platforms[id].sensor_num = i;
240 sensor_cells[id].id = sensor_type[resp->info.type];
241 sensor_cells[id].platform_data = &sensor_platforms[id];
242 sensor_cells[id].pdata_size =
243 sizeof(struct cros_ec_sensor_platform);
244
245 sensor_type[resp->info.type]++;
246 id++;
247 }
248
249 if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
250 ec->has_kb_wake_angle = true;
251
252 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
253 sensor_cells[id].name = "cros-ec-ring";
254 id++;
255 }
256 if (cros_ec_check_features(ec,
257 EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
258 sensor_cells[id].name = "cros-ec-lid-angle";
259 id++;
260 }
261
262 ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
263 NULL, 0, NULL);
264 if (ret)
265 dev_err(ec->dev, "failed to add EC sensors\n");
266
267 kfree(sensor_platforms);
268error_platforms:
269 kfree(sensor_cells);
270error:
271 kfree(msg);
272}
273
274static struct cros_ec_sensor_platform sensor_platforms[] = {
275 { .sensor_num = 0 },
276 { .sensor_num = 1 }
277};
278
279static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
280 {
281 .name = "cros-ec-accel-legacy",
282 .platform_data = &sensor_platforms[0],
283 .pdata_size = sizeof(struct cros_ec_sensor_platform),
284 },
285 {
286 .name = "cros-ec-accel-legacy",
287 .platform_data = &sensor_platforms[1],
288 .pdata_size = sizeof(struct cros_ec_sensor_platform),
289 }
290};
291
292static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
293{
294 struct cros_ec_device *ec_dev = ec->ec_dev;
295 u8 status;
296 int ret;
297
298 /*
299 * ECs that need legacy support are the main EC, directly connected to
300 * the AP.
301 */
302 if (ec->cmd_offset != 0)
303 return;
304
305 /*
306 * Check if EC supports direct memory reads and if EC has
307 * accelerometers.
308 */
309 if (ec_dev->cmd_readmem) {
310 ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
311 &status);
312 if (ret < 0) {
313 dev_warn(ec->dev, "EC direct read error.\n");
314 return;
315 }
316
317 /* Check if EC has accelerometers. */
318 if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
319 dev_info(ec->dev, "EC does not have accelerometers.\n");
320 return;
321 }
322 }
323
324 /*
325 * The device may still support accelerometers:
326 * it would be an older ARM based device that do not suppor the
327 * EC_CMD_GET_FEATURES command.
328 *
329 * Register 2 accelerometers, we will fail in the IIO driver if there
330 * are no sensors.
331 */
332 ret = mfd_add_hotplug_devices(ec->dev, cros_ec_accel_legacy_cells,
333 ARRAY_SIZE(cros_ec_accel_legacy_cells));
334 if (ret)
335 dev_err(ec_dev->dev, "failed to add EC sensors\n");
336}
337
338static int ec_device_probe(struct platform_device *pdev)
339{
340 int retval = -ENOMEM;
341 struct device_node *node;
342 struct device *dev = &pdev->dev;
343 struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
344 struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
345 int i;
346
347 if (!ec)
348 return retval;
349
350 dev_set_drvdata(dev, ec);
351 ec->ec_dev = dev_get_drvdata(dev->parent);
352 ec->dev = dev;
353 ec->cmd_offset = ec_platform->cmd_offset;
354 ec->features[0] = -1U; /* Not cached yet */
355 ec->features[1] = -1U; /* Not cached yet */
356 device_initialize(&ec->class_dev);
357
358 for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
359 /*
360 * Check whether this is actually a dedicated MCU rather
361 * than an standard EC.
362 */
363 if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
364 dev_info(dev, "CrOS %s MCU detected\n",
365 cros_mcu_devices[i].desc);
366 /*
367 * Help userspace differentiating ECs from other MCU,
368 * regardless of the probing order.
369 */
370 ec_platform->ec_name = cros_mcu_devices[i].name;
371 break;
372 }
373 }
374
375 /*
376 * Add the class device
377 */
378 ec->class_dev.class = &cros_class;
379 ec->class_dev.parent = dev;
380 ec->class_dev.release = cros_ec_class_release;
381
382 retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
383 if (retval) {
384 dev_err(dev, "dev_set_name failed => %d\n", retval);
385 goto failed;
386 }
387
388 retval = device_add(&ec->class_dev);
389 if (retval)
390 goto failed;
391
392 /* check whether this EC is a sensor hub. */
393 if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
394 cros_ec_sensors_register(ec);
395 else
396 /* Workaroud for older EC firmware */
397 cros_ec_accel_legacy_register(ec);
398
399 /*
400 * The following subdevices can be detected by sending the
401 * EC_FEATURE_GET_CMD Embedded Controller device.
402 */
403 for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
404 if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
405 retval = mfd_add_hotplug_devices(ec->dev,
406 cros_subdevices[i].mfd_cells,
407 cros_subdevices[i].num_cells);
408 if (retval)
409 dev_err(ec->dev,
410 "failed to add %s subdevice: %d\n",
411 cros_subdevices[i].mfd_cells->name,
412 retval);
413 }
414 }
415
416 /*
417 * The following subdevices cannot be detected by sending the
418 * EC_FEATURE_GET_CMD to the Embedded Controller device.
419 */
420 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
421 ARRAY_SIZE(cros_ec_platform_cells));
422 if (retval)
423 dev_warn(ec->dev,
424 "failed to add cros-ec platform devices: %d\n",
425 retval);
426
427 /* Check whether this EC instance has a VBC NVRAM */
428 node = ec->ec_dev->dev->of_node;
429 if (of_property_read_bool(node, "google,has-vbc-nvram")) {
430 retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
431 ARRAY_SIZE(cros_ec_vbc_cells));
432 if (retval)
433 dev_warn(ec->dev, "failed to add VBC devices: %d\n",
434 retval);
435 }
436
437 return 0;
438
439failed:
440 put_device(&ec->class_dev);
441 return retval;
442}
443
444static int ec_device_remove(struct platform_device *pdev)
445{
446 struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
447
448 mfd_remove_devices(ec->dev);
449 device_unregister(&ec->class_dev);
450 return 0;
451}
452
453static const struct platform_device_id cros_ec_id[] = {
454 { DRV_NAME, 0 },
455 { /* sentinel */ }
456};
457MODULE_DEVICE_TABLE(platform, cros_ec_id);
458
459static struct platform_driver cros_ec_dev_driver = {
460 .driver = {
461 .name = DRV_NAME,
462 },
463 .id_table = cros_ec_id,
464 .probe = ec_device_probe,
465 .remove = ec_device_remove,
466};
467
468static int __init cros_ec_dev_init(void)
469{
470 int ret;
471
472 ret = class_register(&cros_class);
473 if (ret) {
474 pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
475 return ret;
476 }
477
478 /* Register the driver */
479 ret = platform_driver_register(&cros_ec_dev_driver);
480 if (ret < 0) {
481 pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
482 goto failed_devreg;
483 }
484 return 0;
485
486failed_devreg:
487 class_unregister(&cros_class);
488 return ret;
489}
490
491static void __exit cros_ec_dev_exit(void)
492{
493 platform_driver_unregister(&cros_ec_dev_driver);
494 class_unregister(&cros_class);
495}
496
497module_init(cros_ec_dev_init);
498module_exit(cros_ec_dev_exit);
499
500MODULE_ALIAS("platform:" DRV_NAME);
501MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
502MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
503MODULE_VERSION("1.0");
504MODULE_LICENSE("GPL");