2 * Fuel gauge driver for Maxim 17042 / 8966 / 8997
3 * Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
5 * Copyright (C) 2011 Samsung Electronics
6 * MyungJoo Ham <myungjoo.ham@samsung.com>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * This driver is based on max17040_battery.c
25 #include <linux/init.h>
26 #include <linux/module.h>
27 #include <linux/slab.h>
28 #include <linux/i2c.h>
29 #include <linux/delay.h>
30 #include <linux/interrupt.h>
32 #include <linux/mod_devicetable.h>
33 #include <linux/power_supply.h>
34 #include <linux/power/max17042_battery.h>
37 /* Status register bits */
38 #define STATUS_POR_BIT (1 << 1)
39 #define STATUS_BST_BIT (1 << 3)
40 #define STATUS_VMN_BIT (1 << 8)
41 #define STATUS_TMN_BIT (1 << 9)
42 #define STATUS_SMN_BIT (1 << 10)
43 #define STATUS_BI_BIT (1 << 11)
44 #define STATUS_VMX_BIT (1 << 12)
45 #define STATUS_TMX_BIT (1 << 13)
46 #define STATUS_SMX_BIT (1 << 14)
47 #define STATUS_BR_BIT (1 << 15)
49 /* Interrupt mask bits */
50 #define CONFIG_ALRT_BIT_ENBL (1 << 2)
51 #define STATUS_INTR_SOCMIN_BIT (1 << 10)
52 #define STATUS_INTR_SOCMAX_BIT (1 << 14)
54 #define VFSOC0_LOCK 0x0000
55 #define VFSOC0_UNLOCK 0x0080
56 #define MODEL_UNLOCK1 0X0059
57 #define MODEL_UNLOCK2 0X00C4
58 #define MODEL_LOCK1 0X0000
59 #define MODEL_LOCK2 0X0000
61 #define dQ_ACC_DIV 0x4
62 #define dP_ACC_100 0x1900
63 #define dP_ACC_200 0x3200
65 struct max17042_chip {
66 struct i2c_client *client;
67 struct power_supply battery;
68 struct max17042_platform_data *pdata;
69 struct work_struct work;
73 static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
75 int ret = i2c_smbus_write_word_data(client, reg, value);
78 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
83 static int max17042_read_reg(struct i2c_client *client, u8 reg)
85 int ret = i2c_smbus_read_word_data(client, reg);
88 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
93 static void max17042_set_reg(struct i2c_client *client,
94 struct max17042_reg_data *data, int size)
98 for (i = 0; i < size; i++)
99 max17042_write_reg(client, data[i].addr, data[i].data);
102 static enum power_supply_property max17042_battery_props[] = {
103 POWER_SUPPLY_PROP_PRESENT,
104 POWER_SUPPLY_PROP_CYCLE_COUNT,
105 POWER_SUPPLY_PROP_VOLTAGE_MAX,
106 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
107 POWER_SUPPLY_PROP_VOLTAGE_NOW,
108 POWER_SUPPLY_PROP_VOLTAGE_AVG,
109 POWER_SUPPLY_PROP_CAPACITY,
110 POWER_SUPPLY_PROP_CHARGE_FULL,
111 POWER_SUPPLY_PROP_TEMP,
112 POWER_SUPPLY_PROP_CURRENT_NOW,
113 POWER_SUPPLY_PROP_CURRENT_AVG,
116 static int max17042_get_property(struct power_supply *psy,
117 enum power_supply_property psp,
118 union power_supply_propval *val)
120 struct max17042_chip *chip = container_of(psy,
121 struct max17042_chip, battery);
124 if (!chip->init_complete)
128 case POWER_SUPPLY_PROP_PRESENT:
129 ret = max17042_read_reg(chip->client, MAX17042_STATUS);
133 if (ret & MAX17042_STATUS_BattAbsent)
138 case POWER_SUPPLY_PROP_CYCLE_COUNT:
139 ret = max17042_read_reg(chip->client, MAX17042_Cycles);
145 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
146 ret = max17042_read_reg(chip->client, MAX17042_MinMaxVolt);
150 val->intval = ret >> 8;
151 val->intval *= 20000; /* Units of LSB = 20mV */
153 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
154 ret = max17042_read_reg(chip->client, MAX17042_V_empty);
158 val->intval = ret >> 7;
159 val->intval *= 10000; /* Units of LSB = 10mV */
161 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
162 ret = max17042_read_reg(chip->client, MAX17042_VCELL);
166 val->intval = ret * 625 / 8;
168 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
169 ret = max17042_read_reg(chip->client, MAX17042_AvgVCELL);
173 val->intval = ret * 625 / 8;
175 case POWER_SUPPLY_PROP_CAPACITY:
176 ret = max17042_read_reg(chip->client, MAX17042_RepSOC);
180 val->intval = ret >> 8;
182 case POWER_SUPPLY_PROP_CHARGE_FULL:
183 ret = max17042_read_reg(chip->client, MAX17042_FullCAP);
187 val->intval = ret * 1000 / 2;
189 case POWER_SUPPLY_PROP_TEMP:
190 ret = max17042_read_reg(chip->client, MAX17042_TEMP);
195 /* The value is signed. */
196 if (val->intval & 0x8000) {
197 val->intval = (0x7fff & ~val->intval) + 1;
200 /* The value is converted into deci-centigrade scale */
201 /* Units of LSB = 1 / 256 degree Celsius */
202 val->intval = val->intval * 10 / 256;
204 case POWER_SUPPLY_PROP_CURRENT_NOW:
205 if (chip->pdata->enable_current_sense) {
206 ret = max17042_read_reg(chip->client, MAX17042_Current);
211 if (val->intval & 0x8000) {
213 val->intval = ~val->intval & 0x7fff;
217 val->intval *= 1562500 / chip->pdata->r_sns;
222 case POWER_SUPPLY_PROP_CURRENT_AVG:
223 if (chip->pdata->enable_current_sense) {
224 ret = max17042_read_reg(chip->client,
225 MAX17042_AvgCurrent);
230 if (val->intval & 0x8000) {
232 val->intval = ~val->intval & 0x7fff;
236 val->intval *= 1562500 / chip->pdata->r_sns;
247 static int max17042_write_verify_reg(struct i2c_client *client,
255 ret = i2c_smbus_write_word_data(client, reg, value);
256 read_value = max17042_read_reg(client, reg);
257 if (read_value != value) {
261 } while (retries && read_value != value);
264 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
269 static inline void max17042_override_por(
270 struct i2c_client *client, u8 reg, u16 value)
273 max17042_write_reg(client, reg, value);
276 static inline void max10742_unlock_model(struct max17042_chip *chip)
278 struct i2c_client *client = chip->client;
279 max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_UNLOCK1);
280 max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_UNLOCK2);
283 static inline void max10742_lock_model(struct max17042_chip *chip)
285 struct i2c_client *client = chip->client;
286 max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_LOCK1);
287 max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_LOCK2);
290 static inline void max17042_write_model_data(struct max17042_chip *chip,
293 struct i2c_client *client = chip->client;
295 for (i = 0; i < size; i++)
296 max17042_write_reg(client, addr + i,
297 chip->pdata->config_data->cell_char_tbl[i]);
300 static inline void max17042_read_model_data(struct max17042_chip *chip,
301 u8 addr, u16 *data, int size)
303 struct i2c_client *client = chip->client;
306 for (i = 0; i < size; i++)
307 data[i] = max17042_read_reg(client, addr + i);
310 static inline int max17042_model_data_compare(struct max17042_chip *chip,
311 u16 *data1, u16 *data2, int size)
315 if (memcmp(data1, data2, size)) {
316 dev_err(&chip->client->dev, "%s compare failed\n", __func__);
317 for (i = 0; i < size; i++)
318 dev_info(&chip->client->dev, "0x%x, 0x%x",
320 dev_info(&chip->client->dev, "\n");
326 static int max17042_init_model(struct max17042_chip *chip)
329 int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl);
332 temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL);
336 max10742_unlock_model(chip);
337 max17042_write_model_data(chip, MAX17042_MODELChrTbl,
339 max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
342 ret = max17042_model_data_compare(
344 chip->pdata->config_data->cell_char_tbl,
348 max10742_lock_model(chip);
354 static int max17042_verify_model_lock(struct max17042_chip *chip)
357 int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl);
361 temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL);
365 max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
367 for (i = 0; i < table_size; i++)
375 static void max17042_write_config_regs(struct max17042_chip *chip)
377 struct max17042_config_data *config = chip->pdata->config_data;
379 max17042_write_reg(chip->client, MAX17042_CONFIG, config->config);
380 max17042_write_reg(chip->client, MAX17042_LearnCFG, config->learn_cfg);
381 max17042_write_reg(chip->client, MAX17042_FilterCFG,
383 max17042_write_reg(chip->client, MAX17042_RelaxCFG, config->relax_cfg);
386 static void max17042_write_custom_regs(struct max17042_chip *chip)
388 struct max17042_config_data *config = chip->pdata->config_data;
390 max17042_write_verify_reg(chip->client, MAX17042_RCOMP0,
392 max17042_write_verify_reg(chip->client, MAX17042_TempCo,
394 max17042_write_reg(chip->client, MAX17042_EmptyTempCo,
395 config->empty_tempco);
396 max17042_write_verify_reg(chip->client, MAX17042_K_empty0,
398 max17042_write_verify_reg(chip->client, MAX17042_ICHGTerm,
402 static void max17042_update_capacity_regs(struct max17042_chip *chip)
404 struct max17042_config_data *config = chip->pdata->config_data;
406 max17042_write_verify_reg(chip->client, MAX17042_FullCAP,
408 max17042_write_reg(chip->client, MAX17042_DesignCap,
410 max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom,
414 static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
418 vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC);
419 max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
420 max17042_write_verify_reg(chip->client, MAX17042_VFSOC0, vfSoc);
421 max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
424 static void max17042_load_new_capacity_params(struct max17042_chip *chip)
426 u16 full_cap0, rep_cap, dq_acc, vfSoc;
429 struct max17042_config_data *config = chip->pdata->config_data;
431 full_cap0 = max17042_read_reg(chip->client, MAX17042_FullCAP0);
432 vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC);
434 /* fg_vfSoc needs to shifted by 8 bits to get the
435 * perc in 1% accuracy, to get the right rem_cap multiply
436 * full_cap0, fg_vfSoc and devide by 100
438 rem_cap = ((vfSoc >> 8) * full_cap0) / 100;
439 max17042_write_verify_reg(chip->client, MAX17042_RemCap, (u16)rem_cap);
441 rep_cap = (u16)rem_cap;
442 max17042_write_verify_reg(chip->client, MAX17042_RepCap, rep_cap);
444 /* Write dQ_acc to 200% of Capacity and dP_acc to 200% */
445 dq_acc = config->fullcap / dQ_ACC_DIV;
446 max17042_write_verify_reg(chip->client, MAX17042_dQacc, dq_acc);
447 max17042_write_verify_reg(chip->client, MAX17042_dPacc, dP_ACC_200);
449 max17042_write_verify_reg(chip->client, MAX17042_FullCAP,
451 max17042_write_reg(chip->client, MAX17042_DesignCap,
453 max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom,
458 * Block write all the override values coming from platform data.
459 * This function MUST be called before the POR initialization proceedure
460 * specified by maxim.
462 static inline void max17042_override_por_values(struct max17042_chip *chip)
464 struct i2c_client *client = chip->client;
465 struct max17042_config_data *config = chip->pdata->config_data;
467 max17042_override_por(client, MAX17042_TGAIN, config->tgain);
468 max17042_override_por(client, MAx17042_TOFF, config->toff);
469 max17042_override_por(client, MAX17042_CGAIN, config->cgain);
470 max17042_override_por(client, MAX17042_COFF, config->coff);
472 max17042_override_por(client, MAX17042_VALRT_Th, config->valrt_thresh);
473 max17042_override_por(client, MAX17042_TALRT_Th, config->talrt_thresh);
474 max17042_override_por(client, MAX17042_SALRT_Th,
475 config->soc_alrt_thresh);
476 max17042_override_por(client, MAX17042_CONFIG, config->config);
477 max17042_override_por(client, MAX17042_SHDNTIMER, config->shdntimer);
479 max17042_override_por(client, MAX17042_DesignCap, config->design_cap);
480 max17042_override_por(client, MAX17042_ICHGTerm, config->ichgt_term);
482 max17042_override_por(client, MAX17042_AtRate, config->at_rate);
483 max17042_override_por(client, MAX17042_LearnCFG, config->learn_cfg);
484 max17042_override_por(client, MAX17042_FilterCFG, config->filter_cfg);
485 max17042_override_por(client, MAX17042_RelaxCFG, config->relax_cfg);
486 max17042_override_por(client, MAX17042_MiscCFG, config->misc_cfg);
487 max17042_override_por(client, MAX17042_MaskSOC, config->masksoc);
489 max17042_override_por(client, MAX17042_FullCAP, config->fullcap);
490 max17042_override_por(client, MAX17042_FullCAPNom, config->fullcapnom);
491 max17042_override_por(client, MAX17042_SOC_empty, config->socempty);
492 max17042_override_por(client, MAX17042_LAvg_empty, config->lavg_empty);
493 max17042_override_por(client, MAX17042_dQacc, config->dqacc);
494 max17042_override_por(client, MAX17042_dPacc, config->dpacc);
496 max17042_override_por(client, MAX17042_V_empty, config->vempty);
497 max17042_override_por(client, MAX17042_TempNom, config->temp_nom);
498 max17042_override_por(client, MAX17042_TempLim, config->temp_lim);
499 max17042_override_por(client, MAX17042_FCTC, config->fctc);
500 max17042_override_por(client, MAX17042_RCOMP0, config->rcomp0);
501 max17042_override_por(client, MAX17042_TempCo, config->tcompc0);
502 max17042_override_por(client, MAX17042_EmptyTempCo,
503 config->empty_tempco);
504 max17042_override_por(client, MAX17042_K_empty0, config->kempty0);
507 static int max17042_init_chip(struct max17042_chip *chip)
512 max17042_override_por_values(chip);
513 /* After Power up, the MAX17042 requires 500mS in order
514 * to perform signal debouncing and initial SOC reporting
518 /* Initialize configaration */
519 max17042_write_config_regs(chip);
521 /* write cell characterization data */
522 ret = max17042_init_model(chip);
524 dev_err(&chip->client->dev, "%s init failed\n",
528 max17042_verify_model_lock(chip);
530 dev_err(&chip->client->dev, "%s lock verify failed\n",
534 /* write custom parameters */
535 max17042_write_custom_regs(chip);
537 /* update capacity params */
538 max17042_update_capacity_regs(chip);
540 /* delay must be atleast 350mS to allow VFSOC
541 * to be calculated from the new configuration
545 /* reset vfsoc0 reg */
546 max17042_reset_vfsoc0_reg(chip);
548 /* load new capacity params */
549 max17042_load_new_capacity_params(chip);
551 /* Init complete, Clear the POR bit */
552 val = max17042_read_reg(chip->client, MAX17042_STATUS);
553 max17042_write_reg(chip->client, MAX17042_STATUS,
554 val & (~STATUS_POR_BIT));
558 static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off)
562 /* program interrupt thesholds such that we should
563 * get interrupt for every 'off' perc change in the soc
565 soc = max17042_read_reg(chip->client, MAX17042_RepSOC) >> 8;
566 soc_tr = (soc + off) << 8;
567 soc_tr |= (soc - off);
568 max17042_write_reg(chip->client, MAX17042_SALRT_Th, soc_tr);
571 static irqreturn_t max17042_thread_handler(int id, void *dev)
573 struct max17042_chip *chip = dev;
576 val = max17042_read_reg(chip->client, MAX17042_STATUS);
577 if ((val & STATUS_INTR_SOCMIN_BIT) ||
578 (val & STATUS_INTR_SOCMAX_BIT)) {
579 dev_info(&chip->client->dev, "SOC threshold INTR\n");
580 max17042_set_soc_threshold(chip, 1);
583 power_supply_changed(&chip->battery);
587 static void max17042_init_worker(struct work_struct *work)
589 struct max17042_chip *chip = container_of(work,
590 struct max17042_chip, work);
593 /* Initialize registers according to values from the platform data */
594 if (chip->pdata->enable_por_init && chip->pdata->config_data) {
595 ret = max17042_init_chip(chip);
600 chip->init_complete = 1;
604 static struct max17042_platform_data *
605 max17042_get_pdata(struct device *dev)
607 struct device_node *np = dev->of_node;
609 struct max17042_platform_data *pdata;
612 return dev->platform_data;
614 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
619 * Require current sense resistor value to be specified for
620 * current-sense functionality to be enabled at all.
622 if (of_property_read_u32(np, "maxim,rsns-microohm", &prop) == 0) {
624 pdata->enable_current_sense = true;
630 static struct max17042_platform_data *
631 max17042_get_pdata(struct device *dev)
633 return dev->platform_data;
637 static int __devinit max17042_probe(struct i2c_client *client,
638 const struct i2c_device_id *id)
640 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
641 struct max17042_chip *chip;
645 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
648 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
652 chip->client = client;
653 chip->pdata = max17042_get_pdata(&client->dev);
655 dev_err(&client->dev, "no platform data provided\n");
659 i2c_set_clientdata(client, chip);
661 chip->battery.name = "max17042_battery";
662 chip->battery.type = POWER_SUPPLY_TYPE_BATTERY;
663 chip->battery.get_property = max17042_get_property;
664 chip->battery.properties = max17042_battery_props;
665 chip->battery.num_properties = ARRAY_SIZE(max17042_battery_props);
667 /* When current is not measured,
668 * CURRENT_NOW and CURRENT_AVG properties should be invisible. */
669 if (!chip->pdata->enable_current_sense)
670 chip->battery.num_properties -= 2;
672 if (chip->pdata->r_sns == 0)
673 chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
675 if (chip->pdata->init_data)
676 max17042_set_reg(client, chip->pdata->init_data,
677 chip->pdata->num_init_data);
679 if (!chip->pdata->enable_current_sense) {
680 max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
681 max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
682 max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
686 ret = request_threaded_irq(client->irq, NULL,
687 max17042_thread_handler,
688 IRQF_TRIGGER_FALLING,
689 chip->battery.name, chip);
691 reg = max17042_read_reg(client, MAX17042_CONFIG);
692 reg |= CONFIG_ALRT_BIT_ENBL;
693 max17042_write_reg(client, MAX17042_CONFIG, reg);
694 max17042_set_soc_threshold(chip, 1);
696 dev_err(&client->dev, "%s(): cannot get IRQ\n",
700 reg = max17042_read_reg(chip->client, MAX17042_STATUS);
702 if (reg & STATUS_POR_BIT) {
703 INIT_WORK(&chip->work, max17042_init_worker);
704 schedule_work(&chip->work);
706 chip->init_complete = 1;
709 ret = power_supply_register(&client->dev, &chip->battery);
711 dev_err(&client->dev, "failed: power supply register\n");
715 static int __devexit max17042_remove(struct i2c_client *client)
717 struct max17042_chip *chip = i2c_get_clientdata(client);
720 free_irq(client->irq, chip);
721 power_supply_unregister(&chip->battery);
726 static int max17042_suspend(struct device *dev)
728 struct max17042_chip *chip = dev_get_drvdata(dev);
730 /* disable the irq and enable irq_wake
731 * capability to the interrupt line.
733 if (chip->client->irq) {
734 disable_irq(chip->client->irq);
735 enable_irq_wake(chip->client->irq);
741 static int max17042_resume(struct device *dev)
743 struct max17042_chip *chip = dev_get_drvdata(dev);
745 if (chip->client->irq) {
746 disable_irq_wake(chip->client->irq);
747 enable_irq(chip->client->irq);
748 /* re-program the SOC thresholds to 1% change */
749 max17042_set_soc_threshold(chip, 1);
755 #define max17042_suspend NULL
756 #define max17042_resume NULL
760 static const struct of_device_id max17042_dt_match[] = {
761 { .compatible = "maxim,max17042" },
764 MODULE_DEVICE_TABLE(of, max17042_dt_match);
767 static const struct i2c_device_id max17042_id[] = {
771 MODULE_DEVICE_TABLE(i2c, max17042_id);
773 static const struct dev_pm_ops max17042_pm_ops = {
774 .suspend = max17042_suspend,
775 .resume = max17042_resume,
778 static struct i2c_driver max17042_i2c_driver = {
781 .of_match_table = of_match_ptr(max17042_dt_match),
782 .pm = &max17042_pm_ops,
784 .probe = max17042_probe,
785 .remove = __devexit_p(max17042_remove),
786 .id_table = max17042_id,
788 module_i2c_driver(max17042_i2c_driver);
790 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
791 MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
792 MODULE_LICENSE("GPL");