Free Electrons

Embedded Linux Experts

  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
583
584
585
586
587
588
589
590
591
592
593
594
595
596
/*
 * Battery driver for Maxim MAX8925
 *
 * Copyright (c) 2009-2010 Marvell International Ltd.
 *	Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/module.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/mfd/max8925.h>

/* registers in GPM */
#define MAX8925_OUT5VEN			0x54
#define MAX8925_OUT3VEN			0x58
#define MAX8925_CHG_CNTL1		0x7c

/* bits definition */
#define MAX8925_CHG_STAT_VSYSLOW	(1 << 0)
#define MAX8925_CHG_STAT_MODE_MASK	(3 << 2)
#define MAX8925_CHG_STAT_EN_MASK	(1 << 4)
#define MAX8925_CHG_MBDET		(1 << 1)
#define MAX8925_CHG_AC_RANGE_MASK	(3 << 6)

/* registers in ADC */
#define MAX8925_ADC_RES_CNFG1		0x06
#define MAX8925_ADC_AVG_CNFG1		0x07
#define MAX8925_ADC_ACQ_CNFG1		0x08
#define MAX8925_ADC_ACQ_CNFG2		0x09
/* 2 bytes registers in below. MSB is 1st, LSB is 2nd. */
#define MAX8925_ADC_AUX2		0x62
#define MAX8925_ADC_VCHG		0x64
#define MAX8925_ADC_VBBATT		0x66
#define MAX8925_ADC_VMBATT		0x68
#define MAX8925_ADC_ISNS		0x6a
#define MAX8925_ADC_THM			0x6c
#define MAX8925_ADC_TDIE		0x6e
#define MAX8925_CMD_AUX2		0xc8
#define MAX8925_CMD_VCHG		0xd0
#define MAX8925_CMD_VBBATT		0xd8
#define MAX8925_CMD_VMBATT		0xe0
#define MAX8925_CMD_ISNS		0xe8
#define MAX8925_CMD_THM			0xf0
#define MAX8925_CMD_TDIE		0xf8

enum {
	MEASURE_AUX2,
	MEASURE_VCHG,
	MEASURE_VBBATT,
	MEASURE_VMBATT,
	MEASURE_ISNS,
	MEASURE_THM,
	MEASURE_TDIE,
	MEASURE_MAX,
};

struct max8925_power_info {
	struct max8925_chip	*chip;
	struct i2c_client	*gpm;
	struct i2c_client	*adc;

	struct power_supply	*ac;
	struct power_supply	*usb;
	struct power_supply	*battery;
	int			irq_base;
	unsigned		ac_online:1;
	unsigned		usb_online:1;
	unsigned		bat_online:1;
	unsigned		chg_mode:2;
	unsigned		batt_detect:1;	/* detecing MB by ID pin */
	unsigned		topoff_threshold:2;
	unsigned		fast_charge:3;
	unsigned		no_temp_support:1;
	unsigned		no_insert_detect:1;

	int (*set_charger) (int);
};

static int __set_charger(struct max8925_power_info *info, int enable)
{
	struct max8925_chip *chip = info->chip;
	if (enable) {
		/* enable charger in platform */
		if (info->set_charger)
			info->set_charger(1);
		/* enable charger */
		max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 0);
	} else {
		/* disable charge */
		max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 1 << 7);
		if (info->set_charger)
			info->set_charger(0);
	}
	dev_dbg(chip->dev, "%s\n", (enable) ? "Enable charger"
		: "Disable charger");
	return 0;
}

static irqreturn_t max8925_charger_handler(int irq, void *data)
{
	struct max8925_power_info *info = (struct max8925_power_info *)data;
	struct max8925_chip *chip = info->chip;

	switch (irq - chip->irq_base) {
	case MAX8925_IRQ_VCHG_DC_R:
		info->ac_online = 1;
		__set_charger(info, 1);
		dev_dbg(chip->dev, "Adapter inserted\n");
		break;
	case MAX8925_IRQ_VCHG_DC_F:
		info->ac_online = 0;
		__set_charger(info, 0);
		dev_dbg(chip->dev, "Adapter removed\n");
		break;
	case MAX8925_IRQ_VCHG_THM_OK_F:
		/* Battery is not ready yet */
		dev_dbg(chip->dev, "Battery temperature is out of range\n");
	case MAX8925_IRQ_VCHG_DC_OVP:
		dev_dbg(chip->dev, "Error detection\n");
		__set_charger(info, 0);
		break;
	case MAX8925_IRQ_VCHG_THM_OK_R:
		/* Battery is ready now */
		dev_dbg(chip->dev, "Battery temperature is in range\n");
		break;
	case MAX8925_IRQ_VCHG_SYSLOW_R:
		/* VSYS is low */
		dev_info(chip->dev, "Sys power is too low\n");
		break;
	case MAX8925_IRQ_VCHG_SYSLOW_F:
		dev_dbg(chip->dev, "Sys power is above low threshold\n");
		break;
	case MAX8925_IRQ_VCHG_DONE:
		__set_charger(info, 0);
		dev_dbg(chip->dev, "Charging is done\n");
		break;
	case MAX8925_IRQ_VCHG_TOPOFF:
		dev_dbg(chip->dev, "Charging in top-off mode\n");
		break;
	case MAX8925_IRQ_VCHG_TMR_FAULT:
		__set_charger(info, 0);
		dev_dbg(chip->dev, "Safe timer is expired\n");
		break;
	case MAX8925_IRQ_VCHG_RST:
		__set_charger(info, 0);
		dev_dbg(chip->dev, "Charger is reset\n");
		break;
	}
	return IRQ_HANDLED;
}

static int start_measure(struct max8925_power_info *info, int type)
{
	unsigned char buf[2] = {0, 0};
	int meas_cmd;
	int meas_reg = 0, ret;

	switch (type) {
	case MEASURE_VCHG:
		meas_cmd = MAX8925_CMD_VCHG;
		meas_reg = MAX8925_ADC_VCHG;
		break;
	case MEASURE_VBBATT:
		meas_cmd = MAX8925_CMD_VBBATT;
		meas_reg = MAX8925_ADC_VBBATT;
		break;
	case MEASURE_VMBATT:
		meas_cmd = MAX8925_CMD_VMBATT;
		meas_reg = MAX8925_ADC_VMBATT;
		break;
	case MEASURE_ISNS:
		meas_cmd = MAX8925_CMD_ISNS;
		meas_reg = MAX8925_ADC_ISNS;
		break;
	default:
		return -EINVAL;
	}

	max8925_reg_write(info->adc, meas_cmd, 0);
	max8925_bulk_read(info->adc, meas_reg, 2, buf);
	ret = ((buf[0]<<8) | buf[1]) >> 4;

	return ret;
}

static int max8925_ac_get_prop(struct power_supply *psy,
			       enum power_supply_property psp,
			       union power_supply_propval *val)
{
	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = info->ac_online;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		if (info->ac_online) {
			ret = start_measure(info, MEASURE_VCHG);
			if (ret >= 0) {
				val->intval = ret * 2000;	/* unit is uV */
				goto out;
			}
		}
		ret = -ENODATA;
		break;
	default:
		ret = -ENODEV;
		break;
	}
out:
	return ret;
}

static enum power_supply_property max8925_ac_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
};

static int max8925_usb_get_prop(struct power_supply *psy,
				enum power_supply_property psp,
				union power_supply_propval *val)
{
	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = info->usb_online;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		if (info->usb_online) {
			ret = start_measure(info, MEASURE_VCHG);
			if (ret >= 0) {
				val->intval = ret * 2000;	/* unit is uV */
				goto out;
			}
		}
		ret = -ENODATA;
		break;
	default:
		ret = -ENODEV;
		break;
	}
out:
	return ret;
}

static enum power_supply_property max8925_usb_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
};

static int max8925_bat_get_prop(struct power_supply *psy,
				enum power_supply_property psp,
				union power_supply_propval *val)
{
	struct max8925_power_info *info = dev_get_drvdata(psy->dev.parent);
	int ret = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = info->bat_online;
		break;
	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
		if (info->bat_online) {
			ret = start_measure(info, MEASURE_VMBATT);
			if (ret >= 0) {
				val->intval = ret * 2000;	/* unit is uV */
				ret = 0;
				break;
			}
		}
		ret = -ENODATA;
		break;
	case POWER_SUPPLY_PROP_CURRENT_NOW:
		if (info->bat_online) {
			ret = start_measure(info, MEASURE_ISNS);
			if (ret >= 0) {
				/* assume r_sns is 0.02 */
				ret = ((ret * 6250) - 3125) /* uA */;
				val->intval = 0;
				if (ret > 0)
					val->intval = ret; /* unit is mA */
				ret = 0;
				break;
			}
		}
		ret = -ENODATA;
		break;
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
		if (!info->bat_online) {
			ret = -ENODATA;
			break;
		}
		ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
		ret = (ret & MAX8925_CHG_STAT_MODE_MASK) >> 2;
		switch (ret) {
		case 1:
			val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
			break;
		case 0:
		case 2:
			val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
			break;
		case 3:
			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
			break;
		}
		ret = 0;
		break;
	case POWER_SUPPLY_PROP_STATUS:
		if (!info->bat_online) {
			ret = -ENODATA;
			break;
		}
		ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
		if (info->usb_online || info->ac_online) {
			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
			if (ret & MAX8925_CHG_STAT_EN_MASK)
				val->intval = POWER_SUPPLY_STATUS_CHARGING;
		} else
			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
		ret = 0;
		break;
	default:
		ret = -ENODEV;
		break;
	}
	return ret;
}

static enum power_supply_property max8925_battery_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_VOLTAGE_NOW,
	POWER_SUPPLY_PROP_CURRENT_NOW,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	POWER_SUPPLY_PROP_STATUS,
};

static const struct power_supply_desc ac_desc = {
	.name		= "max8925-ac",
	.type		= POWER_SUPPLY_TYPE_MAINS,
	.properties	= max8925_ac_props,
	.num_properties	= ARRAY_SIZE(max8925_ac_props),
	.get_property	= max8925_ac_get_prop,
};

static const struct power_supply_desc usb_desc = {
	.name		= "max8925-usb",
	.type		= POWER_SUPPLY_TYPE_USB,
	.properties	= max8925_usb_props,
	.num_properties	= ARRAY_SIZE(max8925_usb_props),
	.get_property	= max8925_usb_get_prop,
};

static const struct power_supply_desc battery_desc = {
	.name		= "max8925-battery",
	.type		= POWER_SUPPLY_TYPE_BATTERY,
	.properties	= max8925_battery_props,
	.num_properties	= ARRAY_SIZE(max8925_battery_props),
	.get_property	= max8925_bat_get_prop,
};

#define REQUEST_IRQ(_irq, _name)					\
do {									\
	ret = request_threaded_irq(chip->irq_base + _irq, NULL,		\
				    max8925_charger_handler,		\
				    IRQF_ONESHOT, _name, info);		\
	if (ret)							\
		dev_err(chip->dev, "Failed to request IRQ #%d: %d\n",	\
			_irq, ret);					\
} while (0)

static int max8925_init_charger(struct max8925_chip *chip,
					  struct max8925_power_info *info)
{
	int ret;

	REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_OVP, "ac-ovp");
	if (!info->no_insert_detect) {
		REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_F, "ac-remove");
		REQUEST_IRQ(MAX8925_IRQ_VCHG_DC_R, "ac-insert");
	}
	if (!info->no_temp_support) {
		REQUEST_IRQ(MAX8925_IRQ_VCHG_THM_OK_R, "batt-temp-in-range");
		REQUEST_IRQ(MAX8925_IRQ_VCHG_THM_OK_F, "batt-temp-out-range");
	}
	REQUEST_IRQ(MAX8925_IRQ_VCHG_SYSLOW_F, "vsys-high");
	REQUEST_IRQ(MAX8925_IRQ_VCHG_SYSLOW_R, "vsys-low");
	REQUEST_IRQ(MAX8925_IRQ_VCHG_RST, "charger-reset");
	REQUEST_IRQ(MAX8925_IRQ_VCHG_DONE, "charger-done");
	REQUEST_IRQ(MAX8925_IRQ_VCHG_TOPOFF, "charger-topoff");
	REQUEST_IRQ(MAX8925_IRQ_VCHG_TMR_FAULT, "charger-timer-expire");

	info->usb_online = 0;
	info->bat_online = 0;

	/* check for power - can miss interrupt at boot time */
	if (start_measure(info, MEASURE_VCHG) * 2000 > 500000)
		info->ac_online = 1;
	else
		info->ac_online = 0;

	ret = max8925_reg_read(info->gpm, MAX8925_CHG_STATUS);
	if (ret >= 0) {
		/*
		 * If battery detection is enabled, ID pin of battery is
		 * connected to MBDET pin of MAX8925. It could be used to
		 * detect battery presence.
		 * Otherwise, we have to assume that battery is always on.
		 */
		if (info->batt_detect)
			info->bat_online = (ret & MAX8925_CHG_MBDET) ? 0 : 1;
		else
			info->bat_online = 1;
		if (ret & MAX8925_CHG_AC_RANGE_MASK)
			info->ac_online = 1;
		else
			info->ac_online = 0;
	}
	/* disable charge */
	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 1 << 7, 1 << 7);
	/* set charging current in charge topoff mode */
	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 3 << 5,
			 info->topoff_threshold << 5);
	/* set charing current in fast charge mode */
	max8925_set_bits(info->gpm, MAX8925_CHG_CNTL1, 7, info->fast_charge);

	return 0;
}

static int max8925_deinit_charger(struct max8925_power_info *info)
{
	struct max8925_chip *chip = info->chip;
	int irq;

	irq = chip->irq_base + MAX8925_IRQ_VCHG_DC_OVP;
	for (; irq <= chip->irq_base + MAX8925_IRQ_VCHG_TMR_FAULT; irq++)
		free_irq(irq, info);

	return 0;
}

#ifdef CONFIG_OF
static struct max8925_power_pdata *
max8925_power_dt_init(struct platform_device *pdev)
{
	struct device_node *nproot = pdev->dev.parent->of_node;
	struct device_node *np;
	int batt_detect;
	int topoff_threshold;
	int fast_charge;
	int no_temp_support;
	int no_insert_detect;
	struct max8925_power_pdata *pdata;

	if (!nproot)
		return pdev->dev.platform_data;

	np = of_get_child_by_name(nproot, "charger");
	if (!np) {
		dev_err(&pdev->dev, "failed to find charger node\n");
		return NULL;
	}

	pdata = devm_kzalloc(&pdev->dev,
			sizeof(struct max8925_power_pdata),
			GFP_KERNEL);
	if (!pdata)
		goto ret;

	of_property_read_u32(np, "topoff-threshold", &topoff_threshold);
	of_property_read_u32(np, "batt-detect", &batt_detect);
	of_property_read_u32(np, "fast-charge", &fast_charge);
	of_property_read_u32(np, "no-insert-detect", &no_insert_detect);
	of_property_read_u32(np, "no-temp-support", &no_temp_support);

	pdata->batt_detect = batt_detect;
	pdata->fast_charge = fast_charge;
	pdata->topoff_threshold = topoff_threshold;
	pdata->no_insert_detect = no_insert_detect;
	pdata->no_temp_support = no_temp_support;

ret:
	of_node_put(np);
	return pdata;
}
#else
static struct max8925_power_pdata *
max8925_power_dt_init(struct platform_device *pdev)
{
	return pdev->dev.platform_data;
}
#endif

static int max8925_power_probe(struct platform_device *pdev)
{
	struct max8925_chip *chip = dev_get_drvdata(pdev->dev.parent);
	struct power_supply_config psy_cfg = {}; /* Only for ac and usb */
	struct max8925_power_pdata *pdata = NULL;
	struct max8925_power_info *info;
	int ret;

	pdata = max8925_power_dt_init(pdev);
	if (!pdata) {
		dev_err(&pdev->dev, "platform data isn't assigned to "
			"power supply\n");
		return -EINVAL;
	}

	info = devm_kzalloc(&pdev->dev, sizeof(struct max8925_power_info),
				GFP_KERNEL);
	if (!info)
		return -ENOMEM;
	info->chip = chip;
	info->gpm = chip->i2c;
	info->adc = chip->adc;
	platform_set_drvdata(pdev, info);

	psy_cfg.supplied_to = pdata->supplied_to;
	psy_cfg.num_supplicants = pdata->num_supplicants;

	info->ac = power_supply_register(&pdev->dev, &ac_desc, &psy_cfg);
	if (IS_ERR(info->ac)) {
		ret = PTR_ERR(info->ac);
		goto out;
	}
	info->ac->dev.parent = &pdev->dev;

	info->usb = power_supply_register(&pdev->dev, &usb_desc, &psy_cfg);
	if (IS_ERR(info->usb)) {
		ret = PTR_ERR(info->usb);
		goto out_unregister_ac;
	}
	info->usb->dev.parent = &pdev->dev;

	info->battery = power_supply_register(&pdev->dev, &battery_desc, NULL);
	if (IS_ERR(info->battery)) {
		ret = PTR_ERR(info->battery);
		goto out_unregister_usb;
	}
	info->battery->dev.parent = &pdev->dev;

	info->batt_detect = pdata->batt_detect;
	info->topoff_threshold = pdata->topoff_threshold;
	info->fast_charge = pdata->fast_charge;
	info->set_charger = pdata->set_charger;
	info->no_temp_support = pdata->no_temp_support;
	info->no_insert_detect = pdata->no_insert_detect;

	max8925_init_charger(chip, info);
	return 0;
out_unregister_usb:
	power_supply_unregister(info->usb);
out_unregister_ac:
	power_supply_unregister(info->ac);
out:
	return ret;
}

static int max8925_power_remove(struct platform_device *pdev)
{
	struct max8925_power_info *info = platform_get_drvdata(pdev);

	if (info) {
		power_supply_unregister(info->ac);
		power_supply_unregister(info->usb);
		power_supply_unregister(info->battery);
		max8925_deinit_charger(info);
	}
	return 0;
}

static struct platform_driver max8925_power_driver = {
	.probe	= max8925_power_probe,
	.remove	= max8925_power_remove,
	.driver	= {
		.name	= "max8925-power",
	},
};

module_platform_driver(max8925_power_driver);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Power supply driver for MAX8925");
MODULE_ALIAS("platform:max8925-power");