summaryrefslogtreecommitdiff
path: root/drivers/platform/surface/surface3_power.c
blob: abac3eec565e873ef5d05b0976f16a5d6ce054cc (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
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
// SPDX-License-Identifier: GPL-2.0+
/*
 * Supports for the power IC on the Surface 3 tablet.
 *
 * (C) Copyright 2016-2018 Red Hat, Inc
 * (C) Copyright 2016-2018 Benjamin Tissoires <benjamin.tissoires@gmail.com>
 * (C) Copyright 2016 Stephen Just <stephenjust@gmail.com>
 *
 * This driver has been reverse-engineered by parsing the DSDT of the Surface 3
 * and looking at the registers of the chips.
 *
 * The DSDT allowed to find out that:
 * - the driver is required for the ACPI BAT0 device to communicate to the chip
 *   through an operation region.
 * - the various defines for the operation region functions to communicate with
 *   this driver
 * - the DSM 3f99e367-6220-4955-8b0f-06ef2ae79412 allows to trigger ACPI
 *   events to BAT0 (the code is all available in the DSDT).
 *
 * Further findings regarding the 2 chips declared in the MSHW0011 are:
 * - there are 2 chips declared:
 *   . 0x22 seems to control the ADP1 line status (and probably the charger)
 *   . 0x55 controls the battery directly
 * - the battery chip uses a SMBus protocol (using plain SMBus allows non
 *   destructive commands):
 *   . the commands/registers used are in the range 0x00..0x7F
 *   . if bit 8 (0x80) is set in the SMBus command, the returned value is the
 *     same as when it is not set. There is a high chance this bit is the
 *     read/write
 *   . the various registers semantic as been deduced by observing the register
 *     dumps.
 */

#include <linux/acpi.h>
#include <linux/bits.h>
#include <linux/freezer.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uuid.h>
#include <asm/unaligned.h>

#define SURFACE_3_POLL_INTERVAL		(2 * HZ)
#define SURFACE_3_STRLEN		10

struct mshw0011_data {
	struct i2c_client	*adp1;
	struct i2c_client	*bat0;
	unsigned short		notify_mask;
	struct task_struct	*poll_task;
	bool			kthread_running;

	bool			charging;
	bool			bat_charging;
	u8			trip_point;
	s32			full_capacity;
};

struct mshw0011_handler_data {
	struct acpi_connection_info	info;
	struct i2c_client		*client;
};

struct bix {
	u32	revision;
	u32	power_unit;
	u32	design_capacity;
	u32	last_full_charg_capacity;
	u32	battery_technology;
	u32	design_voltage;
	u32	design_capacity_of_warning;
	u32	design_capacity_of_low;
	u32	cycle_count;
	u32	measurement_accuracy;
	u32	max_sampling_time;
	u32	min_sampling_time;
	u32	max_average_interval;
	u32	min_average_interval;
	u32	battery_capacity_granularity_1;
	u32	battery_capacity_granularity_2;
	char	model[SURFACE_3_STRLEN];
	char	serial[SURFACE_3_STRLEN];
	char	type[SURFACE_3_STRLEN];
	char	OEM[SURFACE_3_STRLEN];
} __packed;

struct bst {
	u32	battery_state;
	s32	battery_present_rate;
	u32	battery_remaining_capacity;
	u32	battery_present_voltage;
} __packed;

struct gsb_command {
	u8	arg0;
	u8	arg1;
	u8	arg2;
} __packed;

struct gsb_buffer {
	u8	status;
	u8	len;
	u8	ret;
	union {
		struct gsb_command	cmd;
		struct bst		bst;
		struct bix		bix;
	} __packed;
} __packed;

#define ACPI_BATTERY_STATE_DISCHARGING	BIT(0)
#define ACPI_BATTERY_STATE_CHARGING	BIT(1)
#define ACPI_BATTERY_STATE_CRITICAL	BIT(2)

#define MSHW0011_CMD_DEST_BAT0		0x01
#define MSHW0011_CMD_DEST_ADP1		0x03

#define MSHW0011_CMD_BAT0_STA		0x01
#define MSHW0011_CMD_BAT0_BIX		0x02
#define MSHW0011_CMD_BAT0_BCT		0x03
#define MSHW0011_CMD_BAT0_BTM		0x04
#define MSHW0011_CMD_BAT0_BST		0x05
#define MSHW0011_CMD_BAT0_BTP		0x06
#define MSHW0011_CMD_ADP1_PSR		0x07
#define MSHW0011_CMD_BAT0_PSOC		0x09
#define MSHW0011_CMD_BAT0_PMAX		0x0a
#define MSHW0011_CMD_BAT0_PSRC		0x0b
#define MSHW0011_CMD_BAT0_CHGI		0x0c
#define MSHW0011_CMD_BAT0_ARTG		0x0d

#define MSHW0011_NOTIFY_GET_VERSION	0x00
#define MSHW0011_NOTIFY_ADP1		0x01
#define MSHW0011_NOTIFY_BAT0_BST	0x02
#define MSHW0011_NOTIFY_BAT0_BIX	0x05

#define MSHW0011_ADP1_REG_PSR		0x04

#define MSHW0011_BAT0_REG_CAPACITY		0x0c
#define MSHW0011_BAT0_REG_FULL_CHG_CAPACITY	0x0e
#define MSHW0011_BAT0_REG_DESIGN_CAPACITY	0x40
#define MSHW0011_BAT0_REG_VOLTAGE	0x08
#define MSHW0011_BAT0_REG_RATE		0x14
#define MSHW0011_BAT0_REG_OEM		0x45
#define MSHW0011_BAT0_REG_TYPE		0x4e
#define MSHW0011_BAT0_REG_SERIAL_NO	0x56
#define MSHW0011_BAT0_REG_CYCLE_CNT	0x6e

#define MSHW0011_EV_2_5_MASK		GENMASK(8, 0)

/* 3f99e367-6220-4955-8b0f-06ef2ae79412 */
static const guid_t mshw0011_guid =
	GUID_INIT(0x3F99E367, 0x6220, 0x4955, 0x8B, 0x0F, 0x06, 0xEF,
		  0x2A, 0xE7, 0x94, 0x12);

static int
mshw0011_notify(struct mshw0011_data *cdata, u8 arg1, u8 arg2,
		unsigned int *ret_value)
{
	union acpi_object *obj;
	acpi_handle handle;
	unsigned int i;

	handle = ACPI_HANDLE(&cdata->adp1->dev);
	if (!handle)
		return -ENODEV;

	obj = acpi_evaluate_dsm_typed(handle, &mshw0011_guid, arg1, arg2, NULL,
				      ACPI_TYPE_BUFFER);
	if (!obj) {
		dev_err(&cdata->adp1->dev, "device _DSM execution failed\n");
		return -ENODEV;
	}

	*ret_value = 0;
	for (i = 0; i < obj->buffer.length; i++)
		*ret_value |= obj->buffer.pointer[i] << (i * 8);

	ACPI_FREE(obj);
	return 0;
}

static const struct bix default_bix = {
	.revision = 0x00,
	.power_unit = 0x01,
	.design_capacity = 0x1dca,
	.last_full_charg_capacity = 0x1dca,
	.battery_technology = 0x01,
	.design_voltage = 0x10df,
	.design_capacity_of_warning = 0x8f,
	.design_capacity_of_low = 0x47,
	.cycle_count = 0xffffffff,
	.measurement_accuracy = 0x00015f90,
	.max_sampling_time = 0x03e8,
	.min_sampling_time = 0x03e8,
	.max_average_interval = 0x03e8,
	.min_average_interval = 0x03e8,
	.battery_capacity_granularity_1 = 0x45,
	.battery_capacity_granularity_2 = 0x11,
	.model = "P11G8M",
	.serial = "",
	.type = "LION",
	.OEM = "",
};

static int mshw0011_bix(struct mshw0011_data *cdata, struct bix *bix)
{
	struct i2c_client *client = cdata->bat0;
	char buf[SURFACE_3_STRLEN];
	int ret;

	*bix = default_bix;

	/* get design capacity */
	ret = i2c_smbus_read_word_data(client,
				       MSHW0011_BAT0_REG_DESIGN_CAPACITY);
	if (ret < 0) {
		dev_err(&client->dev, "Error reading design capacity: %d\n",
			ret);
		return ret;
	}
	bix->design_capacity = ret;

	/* get last full charge capacity */
	ret = i2c_smbus_read_word_data(client,
				       MSHW0011_BAT0_REG_FULL_CHG_CAPACITY);
	if (ret < 0) {
		dev_err(&client->dev,
			"Error reading last full charge capacity: %d\n", ret);
		return ret;
	}
	bix->last_full_charg_capacity = ret;

	/* get serial number */
	ret = i2c_smbus_read_i2c_block_data(client, MSHW0011_BAT0_REG_SERIAL_NO,
					    sizeof(buf), buf);
	if (ret != sizeof(buf)) {
		dev_err(&client->dev, "Error reading serial no: %d\n", ret);
		return ret;
	}
	snprintf(bix->serial, ARRAY_SIZE(bix->serial), "%3pE%6pE", buf + 7, buf);

	/* get cycle count */
	ret = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_CYCLE_CNT);
	if (ret < 0) {
		dev_err(&client->dev, "Error reading cycle count: %d\n", ret);
		return ret;
	}
	bix->cycle_count = ret;

	/* get OEM name */
	ret = i2c_smbus_read_i2c_block_data(client, MSHW0011_BAT0_REG_OEM,
					    4, buf);
	if (ret != 4) {
		dev_err(&client->dev, "Error reading cycle count: %d\n", ret);
		return ret;
	}
	snprintf(bix->OEM, ARRAY_SIZE(bix->OEM), "%3pE", buf);

	return 0;
}

static int mshw0011_bst(struct mshw0011_data *cdata, struct bst *bst)
{
	struct i2c_client *client = cdata->bat0;
	int rate, capacity, voltage, state;
	s16 tmp;

	rate = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_RATE);
	if (rate < 0)
		return rate;

	capacity = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_CAPACITY);
	if (capacity < 0)
		return capacity;

	voltage = i2c_smbus_read_word_data(client, MSHW0011_BAT0_REG_VOLTAGE);
	if (voltage < 0)
		return voltage;

	tmp = rate;
	bst->battery_present_rate = abs((s32)tmp);

	state = 0;
	if ((s32) tmp > 0)
		state |= ACPI_BATTERY_STATE_CHARGING;
	else if ((s32) tmp < 0)
		state |= ACPI_BATTERY_STATE_DISCHARGING;
	bst->battery_state = state;

	bst->battery_remaining_capacity = capacity;
	bst->battery_present_voltage = voltage;

	return 0;
}

static int mshw0011_adp_psr(struct mshw0011_data *cdata)
{
	return i2c_smbus_read_byte_data(cdata->adp1, MSHW0011_ADP1_REG_PSR);
}

static int mshw0011_isr(struct mshw0011_data *cdata)
{
	struct bst bst;
	struct bix bix;
	int ret;
	bool status, bat_status;

	ret = mshw0011_adp_psr(cdata);
	if (ret < 0)
		return ret;

	status = ret;
	if (status != cdata->charging)
		mshw0011_notify(cdata, cdata->notify_mask,
				MSHW0011_NOTIFY_ADP1, &ret);

	cdata->charging = status;

	ret = mshw0011_bst(cdata, &bst);
	if (ret < 0)
		return ret;

	bat_status = bst.battery_state;
	if (bat_status != cdata->bat_charging)
		mshw0011_notify(cdata, cdata->notify_mask,
				MSHW0011_NOTIFY_BAT0_BST, &ret);

	cdata->bat_charging = bat_status;

	ret = mshw0011_bix(cdata, &bix);
	if (ret < 0)
		return ret;

	if (bix.last_full_charg_capacity != cdata->full_capacity)
		mshw0011_notify(cdata, cdata->notify_mask,
				MSHW0011_NOTIFY_BAT0_BIX, &ret);

	cdata->full_capacity = bix.last_full_charg_capacity;

	return 0;
}

static int mshw0011_poll_task(void *data)
{
	struct mshw0011_data *cdata = data;
	int ret = 0;

	cdata->kthread_running = true;

	set_freezable();

	while (!kthread_should_stop()) {
		schedule_timeout_interruptible(SURFACE_3_POLL_INTERVAL);
		try_to_freeze();
		ret = mshw0011_isr(data);
		if (ret)
			break;
	}

	cdata->kthread_running = false;
	return ret;
}

static acpi_status
mshw0011_space_handler(u32 function, acpi_physical_address command,
			u32 bits, u64 *value64,
			void *handler_context, void *region_context)
{
	struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
	struct mshw0011_handler_data *data = handler_context;
	struct acpi_connection_info *info = &data->info;
	struct acpi_resource_i2c_serialbus *sb;
	struct i2c_client *client = data->client;
	struct mshw0011_data *cdata = i2c_get_clientdata(client);
	struct acpi_resource *ares;
	u32 accessor_type = function >> 16;
	acpi_status ret;
	int status = 1;

	ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
	if (ACPI_FAILURE(ret))
		return ret;

	if (!value64 || !i2c_acpi_get_i2c_resource(ares, &sb)) {
		ret = AE_BAD_PARAMETER;
		goto err;
	}

	if (accessor_type != ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS) {
		ret = AE_BAD_PARAMETER;
		goto err;
	}

	if (gsb->cmd.arg0 == MSHW0011_CMD_DEST_ADP1 &&
	    gsb->cmd.arg1 == MSHW0011_CMD_ADP1_PSR) {
		status = mshw0011_adp_psr(cdata);
		if (status >= 0) {
			ret = AE_OK;
			goto out;
		} else {
			ret = AE_ERROR;
			goto err;
		}
	}

	if (gsb->cmd.arg0 != MSHW0011_CMD_DEST_BAT0) {
		ret = AE_BAD_PARAMETER;
		goto err;
	}

	switch (gsb->cmd.arg1) {
	case MSHW0011_CMD_BAT0_STA:
		break;
	case MSHW0011_CMD_BAT0_BIX:
		ret = mshw0011_bix(cdata, &gsb->bix);
		break;
	case MSHW0011_CMD_BAT0_BTP:
		cdata->trip_point = gsb->cmd.arg2;
		break;
	case MSHW0011_CMD_BAT0_BST:
		ret = mshw0011_bst(cdata, &gsb->bst);
		break;
	default:
		dev_info(&cdata->bat0->dev, "command(0x%02x) is not supported.\n", gsb->cmd.arg1);
		ret = AE_BAD_PARAMETER;
		goto err;
	}

 out:
	gsb->ret = status;
	gsb->status = 0;

 err:
	ACPI_FREE(ares);
	return ret;
}

static int mshw0011_install_space_handler(struct i2c_client *client)
{
	struct acpi_device *adev;
	struct mshw0011_handler_data *data;
	acpi_status status;

	adev = ACPI_COMPANION(&client->dev);
	if (!adev)
		return -ENODEV;

	data = kzalloc(sizeof(struct mshw0011_handler_data),
			    GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->client = client;
	status = acpi_bus_attach_private_data(adev->handle, (void *)data);
	if (ACPI_FAILURE(status)) {
		kfree(data);
		return -ENOMEM;
	}

	status = acpi_install_address_space_handler(adev->handle,
						    ACPI_ADR_SPACE_GSBUS,
						    &mshw0011_space_handler,
						    NULL,
						    data);
	if (ACPI_FAILURE(status)) {
		dev_err(&client->dev, "Error installing i2c space handler\n");
		acpi_bus_detach_private_data(adev->handle);
		kfree(data);
		return -ENOMEM;
	}

	acpi_dev_clear_dependencies(adev);
	return 0;
}

static void mshw0011_remove_space_handler(struct i2c_client *client)
{
	struct mshw0011_handler_data *data;
	acpi_handle handle;
	acpi_status status;

	handle = ACPI_HANDLE(&client->dev);
	if (!handle)
		return;

	acpi_remove_address_space_handler(handle,
				ACPI_ADR_SPACE_GSBUS,
				&mshw0011_space_handler);

	status = acpi_bus_get_private_data(handle, (void **)&data);
	if (ACPI_SUCCESS(status))
		kfree(data);

	acpi_bus_detach_private_data(handle);
}

static int mshw0011_probe(struct i2c_client *client)
{
	struct i2c_board_info board_info;
	struct device *dev = &client->dev;
	struct i2c_client *bat0;
	struct mshw0011_data *data;
	int error, mask;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->adp1 = client;
	i2c_set_clientdata(client, data);

	memset(&board_info, 0, sizeof(board_info));
	strlcpy(board_info.type, "MSHW0011-bat0", I2C_NAME_SIZE);

	bat0 = i2c_acpi_new_device(dev, 1, &board_info);
	if (IS_ERR(bat0))
		return PTR_ERR(bat0);

	data->bat0 = bat0;
	i2c_set_clientdata(bat0, data);

	error = mshw0011_notify(data, 1, MSHW0011_NOTIFY_GET_VERSION, &mask);
	if (error)
		goto out_err;

	data->notify_mask = mask == MSHW0011_EV_2_5_MASK;

	data->poll_task = kthread_run(mshw0011_poll_task, data, "mshw0011_adp");
	if (IS_ERR(data->poll_task)) {
		error = PTR_ERR(data->poll_task);
		dev_err(&client->dev, "Unable to run kthread err %d\n", error);
		goto out_err;
	}

	error = mshw0011_install_space_handler(client);
	if (error)
		goto out_err;

	return 0;

out_err:
	if (data->kthread_running)
		kthread_stop(data->poll_task);
	i2c_unregister_device(data->bat0);
	return error;
}

static int mshw0011_remove(struct i2c_client *client)
{
	struct mshw0011_data *cdata = i2c_get_clientdata(client);

	mshw0011_remove_space_handler(client);

	if (cdata->kthread_running)
		kthread_stop(cdata->poll_task);

	i2c_unregister_device(cdata->bat0);

	return 0;
}

static const struct acpi_device_id mshw0011_acpi_match[] = {
	{ "MSHW0011", 0 },
	{ }
};
MODULE_DEVICE_TABLE(acpi, mshw0011_acpi_match);

static struct i2c_driver mshw0011_driver = {
	.probe_new = mshw0011_probe,
	.remove = mshw0011_remove,
	.driver = {
		.name = "mshw0011",
		.acpi_match_table = mshw0011_acpi_match,
	},
};
module_i2c_driver(mshw0011_driver);

MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@gmail.com>");
MODULE_DESCRIPTION("mshw0011 driver");
MODULE_LICENSE("GPL v2");