summaryrefslogtreecommitdiffstats
path: root/drivers/mfd/cros_ec_dev.c
blob: 6e6dfd6c18711095a4f829f7ad1da36150a9c7d5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
 *
 * Copyright (C) 2014 Google, Inc.
 */

#include <linux/mfd/core.h>
#include <linux/mfd/cros_ec.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/platform_data/cros_ec_chardev.h>
#include <linux/platform_data/cros_ec_commands.h>
#include <linux/platform_data/cros_ec_proto.h>
#include <linux/slab.h>

#define DRV_NAME "cros-ec-dev"

static struct class cros_class = {
	.owner          = THIS_MODULE,
	.name           = "chromeos",
};

/**
 * cros_feature_to_name - CrOS feature id to name/short description.
 * @id: The feature identifier.
 * @name: Device name associated with the feature id.
 * @desc: Short name that will be displayed.
 */
struct cros_feature_to_name {
	unsigned int id;
	const char *name;
	const char *desc;
};

/**
 * cros_feature_to_cells - CrOS feature id to mfd cells association.
 * @id: The feature identifier.
 * @mfd_cells: Pointer to the array of mfd cells that needs to be added.
 * @num_cells: Number of mfd cells into the array.
 */
struct cros_feature_to_cells {
	unsigned int id;
	const struct mfd_cell *mfd_cells;
	unsigned int num_cells;
};

static const struct cros_feature_to_name cros_mcu_devices[] = {
	{
		.id	= EC_FEATURE_FINGERPRINT,
		.name	= CROS_EC_DEV_FP_NAME,
		.desc	= "Fingerprint",
	},
	{
		.id	= EC_FEATURE_ISH,
		.name	= CROS_EC_DEV_ISH_NAME,
		.desc	= "Integrated Sensor Hub",
	},
	{
		.id	= EC_FEATURE_SCP,
		.name	= CROS_EC_DEV_SCP_NAME,
		.desc	= "System Control Processor",
	},
	{
		.id	= EC_FEATURE_TOUCHPAD,
		.name	= CROS_EC_DEV_TP_NAME,
		.desc	= "Touchpad",
	},
};

static const struct mfd_cell cros_ec_cec_cells[] = {
	{ .name = "cros-ec-cec", },
};

static const struct mfd_cell cros_ec_rtc_cells[] = {
	{ .name = "cros-ec-rtc", },
};

static const struct mfd_cell cros_usbpd_charger_cells[] = {
	{ .name = "cros-usbpd-charger", },
	{ .name = "cros-usbpd-logger", },
};

static const struct cros_feature_to_cells cros_subdevices[] = {
	{
		.id		= EC_FEATURE_CEC,
		.mfd_cells	= cros_ec_cec_cells,
		.num_cells	= ARRAY_SIZE(cros_ec_cec_cells),
	},
	{
		.id		= EC_FEATURE_RTC,
		.mfd_cells	= cros_ec_rtc_cells,
		.num_cells	= ARRAY_SIZE(cros_ec_rtc_cells),
	},
	{
		.id		= EC_FEATURE_USB_PD,
		.mfd_cells	= cros_usbpd_charger_cells,
		.num_cells	= ARRAY_SIZE(cros_usbpd_charger_cells),
	},
};

static const struct mfd_cell cros_ec_platform_cells[] = {
	{ .name = "cros-ec-chardev", },
	{ .name = "cros-ec-debugfs", },
	{ .name = "cros-ec-lightbar", },
	{ .name = "cros-ec-sysfs", },
};

static const struct mfd_cell cros_ec_vbc_cells[] = {
	{ .name = "cros-ec-vbc", }
};

static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
{
	struct cros_ec_command *msg;
	int ret;

	if (ec->features[0] == -1U && ec->features[1] == -1U) {
		/* features bitmap not read yet */
		msg = kzalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL);
		if (!msg)
			return -ENOMEM;

		msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset;
		msg->insize = sizeof(ec->features);

		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
		if (ret < 0) {
			dev_warn(ec->dev, "cannot get EC features: %d/%d\n",
				 ret, msg->result);
			memset(ec->features, 0, sizeof(ec->features));
		} else {
			memcpy(ec->features, msg->data, sizeof(ec->features));
		}

		dev_dbg(ec->dev, "EC features %08x %08x\n",
			ec->features[0], ec->features[1]);

		kfree(msg);
	}

	return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
}

static void cros_ec_class_release(struct device *dev)
{
	kfree(to_cros_ec_dev(dev));
}

static void cros_ec_sensors_register(struct cros_ec_dev *ec)
{
	/*
	 * Issue a command to get the number of sensor reported.
	 * Build an array of sensors driver and register them all.
	 */
	int ret, i, id, sensor_num;
	struct mfd_cell *sensor_cells;
	struct cros_ec_sensor_platform *sensor_platforms;
	int sensor_type[MOTIONSENSE_TYPE_MAX];
	struct ec_params_motion_sense *params;
	struct ec_response_motion_sense *resp;
	struct cros_ec_command *msg;

	msg = kzalloc(sizeof(struct cros_ec_command) +
		      max(sizeof(*params), sizeof(*resp)), GFP_KERNEL);
	if (msg == NULL)
		return;

	msg->version = 2;
	msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset;
	msg->outsize = sizeof(*params);
	msg->insize = sizeof(*resp);

	params = (struct ec_params_motion_sense *)msg->data;
	params->cmd = MOTIONSENSE_CMD_DUMP;

	ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
	if (ret < 0) {
		dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n",
			 ret, msg->result);
		goto error;
	}

	resp = (struct ec_response_motion_sense *)msg->data;
	sensor_num = resp->dump.sensor_count;
	/*
	 * Allocate 2 extra sensors if lid angle sensor and/or FIFO are needed.
	 */
	sensor_cells = kcalloc(sensor_num + 2, sizeof(struct mfd_cell),
			       GFP_KERNEL);
	if (sensor_cells == NULL)
		goto error;

	sensor_platforms = kcalloc(sensor_num,
				   sizeof(struct cros_ec_sensor_platform),
				   GFP_KERNEL);
	if (sensor_platforms == NULL)
		goto error_platforms;

	memset(sensor_type, 0, sizeof(sensor_type));
	id = 0;
	for (i = 0; i < sensor_num; i++) {
		params->cmd = MOTIONSENSE_CMD_INFO;
		params->info.sensor_num = i;
		ret = cros_ec_cmd_xfer_status(ec->ec_dev, msg);
		if (ret < 0) {
			dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n",
				 i, ret, msg->result);
			continue;
		}
		switch (resp->info.type) {
		case MOTIONSENSE_TYPE_ACCEL:
			sensor_cells[id].name = "cros-ec-accel";
			break;
		case MOTIONSENSE_TYPE_BARO:
			sensor_cells[id].name = "cros-ec-baro";
			break;
		case MOTIONSENSE_TYPE_GYRO:
			sensor_cells[id].name = "cros-ec-gyro";
			break;
		case MOTIONSENSE_TYPE_MAG:
			sensor_cells[id].name = "cros-ec-mag";
			break;
		case MOTIONSENSE_TYPE_PROX:
			sensor_cells[id].name = "cros-ec-prox";
			break;
		case MOTIONSENSE_TYPE_LIGHT:
			sensor_cells[id].name = "cros-ec-light";
			break;
		case MOTIONSENSE_TYPE_ACTIVITY:
			sensor_cells[id].name = "cros-ec-activity";
			break;
		default:
			dev_warn(ec->dev, "unknown type %d\n", resp->info.type);
			continue;
		}
		sensor_platforms[id].sensor_num = i;
		sensor_cells[id].id = sensor_type[resp->info.type];
		sensor_cells[id].platform_data = &sensor_platforms[id];
		sensor_cells[id].pdata_size =
			sizeof(struct cros_ec_sensor_platform);

		sensor_type[resp->info.type]++;
		id++;
	}

	if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2)
		ec->has_kb_wake_angle = true;

	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) {
		sensor_cells[id].name = "cros-ec-ring";
		id++;
	}
	if (cros_ec_check_features(ec,
				EC_FEATURE_REFINED_TABLET_MODE_HYSTERESIS)) {
		sensor_cells[id].name = "cros-ec-lid-angle";
		id++;
	}

	ret = mfd_add_devices(ec->dev, 0, sensor_cells, id,
			      NULL, 0, NULL);
	if (ret)
		dev_err(ec->dev, "failed to add EC sensors\n");

	kfree(sensor_platforms);
error_platforms:
	kfree(sensor_cells);
error:
	kfree(msg);
}

static struct cros_ec_sensor_platform sensor_platforms[] = {
	{ .sensor_num = 0 },
	{ .sensor_num = 1 }
};

static const struct mfd_cell cros_ec_accel_legacy_cells[] = {
	{
		.name = "cros-ec-accel-legacy",
		.platform_data = &sensor_platforms[0],
		.pdata_size = sizeof(struct cros_ec_sensor_platform),
	},
	{
		.name = "cros-ec-accel-legacy",
		.platform_data = &sensor_platforms[1],
		.pdata_size = sizeof(struct cros_ec_sensor_platform),
	}
};

static void cros_ec_accel_legacy_register(struct cros_ec_dev *ec)
{
	struct cros_ec_device *ec_dev = ec->ec_dev;
	u8 status;
	int ret;

	/*
	 * ECs that need legacy support are the main EC, directly connected to
	 * the AP.
	 */
	if (ec->cmd_offset != 0)
		return;

	/*
	 * Check if EC supports direct memory reads and if EC has
	 * accelerometers.
	 */
	if (ec_dev->cmd_readmem) {
		ret = ec_dev->cmd_readmem(ec_dev, EC_MEMMAP_ACC_STATUS, 1,
					  &status);
		if (ret < 0) {
			dev_warn(ec->dev, "EC direct read error.\n");
			return;
		}

		/* Check if EC has accelerometers. */
		if (!(status & EC_MEMMAP_ACC_STATUS_PRESENCE_BIT)) {
			dev_info(ec->dev, "EC does not have accelerometers.\n");
			return;
		}
	}

	/*
	 * The device may still support accelerometers:
	 * it would be an older ARM based device that do not suppor the
	 * EC_CMD_GET_FEATURES command.
	 *
	 * Register 2 accelerometers, we will fail in the IIO driver if there
	 * are no sensors.
	 */
	ret = mfd_add_hotplug_devices(ec->dev, cros_ec_accel_legacy_cells,
				      ARRAY_SIZE(cros_ec_accel_legacy_cells));
	if (ret)
		dev_err(ec_dev->dev, "failed to add EC sensors\n");
}

static int ec_device_probe(struct platform_device *pdev)
{
	int retval = -ENOMEM;
	struct device_node *node;
	struct device *dev = &pdev->dev;
	struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
	struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
	int i;

	if (!ec)
		return retval;

	dev_set_drvdata(dev, ec);
	ec->ec_dev = dev_get_drvdata(dev->parent);
	ec->dev = dev;
	ec->cmd_offset = ec_platform->cmd_offset;
	ec->features[0] = -1U; /* Not cached yet */
	ec->features[1] = -1U; /* Not cached yet */
	device_initialize(&ec->class_dev);

	for (i = 0; i < ARRAY_SIZE(cros_mcu_devices); i++) {
		/*
		 * Check whether this is actually a dedicated MCU rather
		 * than an standard EC.
		 */
		if (cros_ec_check_features(ec, cros_mcu_devices[i].id)) {
			dev_info(dev, "CrOS %s MCU detected\n",
				 cros_mcu_devices[i].desc);
			/*
			 * Help userspace differentiating ECs from other MCU,
			 * regardless of the probing order.
			 */
			ec_platform->ec_name = cros_mcu_devices[i].name;
			break;
		}
	}

	/*
	 * Add the class device
	 */
	ec->class_dev.class = &cros_class;
	ec->class_dev.parent = dev;
	ec->class_dev.release = cros_ec_class_release;

	retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
	if (retval) {
		dev_err(dev, "dev_set_name failed => %d\n", retval);
		goto failed;
	}

	retval = device_add(&ec->class_dev);
	if (retval)
		goto failed;

	/* check whether this EC is a sensor hub. */
	if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
		cros_ec_sensors_register(ec);
	else
		/* Workaroud for older EC firmware */
		cros_ec_accel_legacy_register(ec);

	/*
	 * The following subdevices can be detected by sending the
	 * EC_FEATURE_GET_CMD Embedded Controller device.
	 */
	for (i = 0; i < ARRAY_SIZE(cros_subdevices); i++) {
		if (cros_ec_check_features(ec, cros_subdevices[i].id)) {
			retval = mfd_add_hotplug_devices(ec->dev,
						cros_subdevices[i].mfd_cells,
						cros_subdevices[i].num_cells);
			if (retval)
				dev_err(ec->dev,
					"failed to add %s subdevice: %d\n",
					cros_subdevices[i].mfd_cells->name,
					retval);
		}
	}

	/*
	 * The following subdevices cannot be detected by sending the
	 * EC_FEATURE_GET_CMD to the Embedded Controller device.
	 */
	retval = mfd_add_hotplug_devices(ec->dev, cros_ec_platform_cells,
					 ARRAY_SIZE(cros_ec_platform_cells));
	if (retval)
		dev_warn(ec->dev,
			 "failed to add cros-ec platform devices: %d\n",
			 retval);

	/* Check whether this EC instance has a VBC NVRAM */
	node = ec->ec_dev->dev->of_node;
	if (of_property_read_bool(node, "google,has-vbc-nvram")) {
		retval = mfd_add_hotplug_devices(ec->dev, cros_ec_vbc_cells,
						ARRAY_SIZE(cros_ec_vbc_cells));
		if (retval)
			dev_warn(ec->dev, "failed to add VBC devices: %d\n",
				 retval);
	}

	return 0;

failed:
	put_device(&ec->class_dev);
	return retval;
}

static int ec_device_remove(struct platform_device *pdev)
{
	struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);

	mfd_remove_devices(ec->dev);
	device_unregister(&ec->class_dev);
	return 0;
}

static const struct platform_device_id cros_ec_id[] = {
	{ DRV_NAME, 0 },
	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, cros_ec_id);

static struct platform_driver cros_ec_dev_driver = {
	.driver = {
		.name = DRV_NAME,
	},
	.id_table = cros_ec_id,
	.probe = ec_device_probe,
	.remove = ec_device_remove,
};

static int __init cros_ec_dev_init(void)
{
	int ret;

	ret  = class_register(&cros_class);
	if (ret) {
		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
		return ret;
	}

	/* Register the driver */
	ret = platform_driver_register(&cros_ec_dev_driver);
	if (ret < 0) {
		pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
		goto failed_devreg;
	}
	return 0;

failed_devreg:
	class_unregister(&cros_class);
	return ret;
}

static void __exit cros_ec_dev_exit(void)
{
	platform_driver_unregister(&cros_ec_dev_driver);
	class_unregister(&cros_class);
}

module_init(cros_ec_dev_init);
module_exit(cros_ec_dev_exit);

MODULE_ALIAS("platform:" DRV_NAME);
MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
MODULE_VERSION("1.0");
MODULE_LICENSE("GPL");