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>
31 #include <linux/mod_devicetable.h>
32 #include <linux/power_supply.h>
33 #include <linux/power/max17042_battery.h>
36 /* Status register bits */
37 #define STATUS_POR_BIT (1 << 1)
38 #define STATUS_BST_BIT (1 << 3)
39 #define STATUS_VMN_BIT (1 << 8)
40 #define STATUS_TMN_BIT (1 << 9)
41 #define STATUS_SMN_BIT (1 << 10)
42 #define STATUS_BI_BIT (1 << 11)
43 #define STATUS_VMX_BIT (1 << 12)
44 #define STATUS_TMX_BIT (1 << 13)
45 #define STATUS_SMX_BIT (1 << 14)
46 #define STATUS_BR_BIT (1 << 15)
48 /* Interrupt mask bits */
49 #define CONFIG_ALRT_BIT_ENBL (1 << 2)
50 #define STATUS_INTR_SOC_BIT (1 << 14)
51 #define STATUS_INTR_LOW_SOC_BIT (1 << 10)
53 #define VFSOC0_LOCK 0x0000
54 #define VFSOC0_UNLOCK 0x0080
55 #define MODEL_UNLOCK1 0X0059
56 #define MODEL_UNLOCK2 0X00C4
57 #define MODEL_LOCK1 0X0000
58 #define MODEL_LOCK2 0X0000
60 #define dQ_ACC_DIV 0x4
61 #define dP_ACC_100 0x1900
62 #define dP_ACC_200 0x3200
64 struct max17042_chip {
65 struct i2c_client *client;
66 struct power_supply battery;
67 struct max17042_platform_data *pdata;
68 struct work_struct work;
72 static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value)
74 int ret = i2c_smbus_write_word_data(client, reg, value);
77 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
82 static int max17042_read_reg(struct i2c_client *client, u8 reg)
84 int ret = i2c_smbus_read_word_data(client, reg);
87 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
92 static void max17042_set_reg(struct i2c_client *client,
93 struct max17042_reg_data *data, int size)
97 for (i = 0; i < size; i++)
98 max17042_write_reg(client, data[i].addr, data[i].data);
101 static enum power_supply_property max17042_battery_props[] = {
102 POWER_SUPPLY_PROP_PRESENT,
103 POWER_SUPPLY_PROP_CYCLE_COUNT,
104 POWER_SUPPLY_PROP_VOLTAGE_MAX,
105 POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
106 POWER_SUPPLY_PROP_VOLTAGE_NOW,
107 POWER_SUPPLY_PROP_VOLTAGE_AVG,
108 POWER_SUPPLY_PROP_CAPACITY,
109 POWER_SUPPLY_PROP_CHARGE_FULL,
110 POWER_SUPPLY_PROP_TEMP,
111 POWER_SUPPLY_PROP_CURRENT_NOW,
112 POWER_SUPPLY_PROP_CURRENT_AVG,
115 static int max17042_get_property(struct power_supply *psy,
116 enum power_supply_property psp,
117 union power_supply_propval *val)
119 struct max17042_chip *chip = container_of(psy,
120 struct max17042_chip, battery);
123 if (!chip->init_complete)
127 case POWER_SUPPLY_PROP_PRESENT:
128 ret = max17042_read_reg(chip->client, MAX17042_STATUS);
132 if (ret & MAX17042_STATUS_BattAbsent)
137 case POWER_SUPPLY_PROP_CYCLE_COUNT:
138 ret = max17042_read_reg(chip->client, MAX17042_Cycles);
144 case POWER_SUPPLY_PROP_VOLTAGE_MAX:
145 ret = max17042_read_reg(chip->client, MAX17042_MinMaxVolt);
149 val->intval = ret >> 8;
150 val->intval *= 20000; /* Units of LSB = 20mV */
152 case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
153 ret = max17042_read_reg(chip->client, MAX17042_V_empty);
157 val->intval = ret >> 7;
158 val->intval *= 10000; /* Units of LSB = 10mV */
160 case POWER_SUPPLY_PROP_VOLTAGE_NOW:
161 ret = max17042_read_reg(chip->client, MAX17042_VCELL);
165 val->intval = ret * 625 / 8;
167 case POWER_SUPPLY_PROP_VOLTAGE_AVG:
168 ret = max17042_read_reg(chip->client, MAX17042_AvgVCELL);
172 val->intval = ret * 625 / 8;
174 case POWER_SUPPLY_PROP_CAPACITY:
175 ret = max17042_read_reg(chip->client, MAX17042_RepSOC);
179 val->intval = ret >> 8;
181 case POWER_SUPPLY_PROP_CHARGE_FULL:
182 ret = max17042_read_reg(chip->client, MAX17042_RepSOC);
186 if ((ret >> 8) >= MAX17042_BATTERY_FULL)
191 case POWER_SUPPLY_PROP_TEMP:
192 ret = max17042_read_reg(chip->client, MAX17042_TEMP);
197 /* The value is signed. */
198 if (val->intval & 0x8000) {
199 val->intval = (0x7fff & ~val->intval) + 1;
202 /* The value is converted into deci-centigrade scale */
203 /* Units of LSB = 1 / 256 degree Celsius */
204 val->intval = val->intval * 10 / 256;
206 case POWER_SUPPLY_PROP_CURRENT_NOW:
207 if (chip->pdata->enable_current_sense) {
208 ret = max17042_read_reg(chip->client, MAX17042_Current);
213 if (val->intval & 0x8000) {
215 val->intval = ~val->intval & 0x7fff;
219 val->intval *= 1562500 / chip->pdata->r_sns;
224 case POWER_SUPPLY_PROP_CURRENT_AVG:
225 if (chip->pdata->enable_current_sense) {
226 ret = max17042_read_reg(chip->client,
227 MAX17042_AvgCurrent);
232 if (val->intval & 0x8000) {
234 val->intval = ~val->intval & 0x7fff;
238 val->intval *= 1562500 / chip->pdata->r_sns;
249 static int max17042_write_verify_reg(struct i2c_client *client,
257 ret = i2c_smbus_write_word_data(client, reg, value);
258 read_value = max17042_read_reg(client, reg);
259 if (read_value != value) {
263 } while (retries && read_value != value);
266 dev_err(&client->dev, "%s: err %d\n", __func__, ret);
271 static inline void max17042_override_por(
272 struct i2c_client *client, u8 reg, u16 value)
275 max17042_write_reg(client, reg, value);
278 static inline void max10742_unlock_model(struct max17042_chip *chip)
280 struct i2c_client *client = chip->client;
281 max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_UNLOCK1);
282 max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_UNLOCK2);
285 static inline void max10742_lock_model(struct max17042_chip *chip)
287 struct i2c_client *client = chip->client;
288 max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_LOCK1);
289 max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_LOCK2);
292 static inline void max17042_write_model_data(struct max17042_chip *chip,
295 struct i2c_client *client = chip->client;
297 for (i = 0; i < size; i++)
298 max17042_write_reg(client, addr + i,
299 chip->pdata->config_data->cell_char_tbl[i]);
302 static inline void max17042_read_model_data(struct max17042_chip *chip,
303 u8 addr, u16 *data, int size)
305 struct i2c_client *client = chip->client;
308 for (i = 0; i < size; i++)
309 data[i] = max17042_read_reg(client, addr + i);
312 static inline int max17042_model_data_compare(struct max17042_chip *chip,
313 u16 *data1, u16 *data2, int size)
317 if (memcmp(data1, data2, size)) {
318 dev_err(&chip->client->dev, "%s compare failed\n", __func__);
319 for (i = 0; i < size; i++)
320 dev_info(&chip->client->dev, "0x%x, 0x%x",
322 dev_info(&chip->client->dev, "\n");
328 static int max17042_init_model(struct max17042_chip *chip)
332 sizeof(chip->pdata->config_data->cell_char_tbl)/sizeof(u16);
335 temp_data = kzalloc(table_size, GFP_KERNEL);
339 max10742_unlock_model(chip);
340 max17042_write_model_data(chip, MAX17042_MODELChrTbl,
342 max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
345 ret = max17042_model_data_compare(
347 chip->pdata->config_data->cell_char_tbl,
351 max10742_lock_model(chip);
357 static int max17042_verify_model_lock(struct max17042_chip *chip)
361 sizeof(chip->pdata->config_data->cell_char_tbl);
365 temp_data = kzalloc(table_size, GFP_KERNEL);
369 max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
371 for (i = 0; i < table_size; i++)
379 static void max17042_write_config_regs(struct max17042_chip *chip)
381 struct max17042_config_data *config = chip->pdata->config_data;
383 max17042_write_reg(chip->client, MAX17042_CONFIG, config->config);
384 max17042_write_reg(chip->client, MAX17042_LearnCFG, config->learn_cfg);
385 max17042_write_reg(chip->client, MAX17042_FilterCFG,
387 max17042_write_reg(chip->client, MAX17042_RelaxCFG, config->relax_cfg);
390 static void max17042_write_custom_regs(struct max17042_chip *chip)
392 struct max17042_config_data *config = chip->pdata->config_data;
394 max17042_write_verify_reg(chip->client, MAX17042_RCOMP0,
396 max17042_write_verify_reg(chip->client, MAX17042_TempCo,
398 max17042_write_reg(chip->client, MAX17042_EmptyTempCo,
399 config->empty_tempco);
400 max17042_write_verify_reg(chip->client, MAX17042_K_empty0,
402 max17042_write_verify_reg(chip->client, MAX17042_ICHGTerm,
406 static void max17042_update_capacity_regs(struct max17042_chip *chip)
408 struct max17042_config_data *config = chip->pdata->config_data;
410 max17042_write_verify_reg(chip->client, MAX17042_FullCAP,
412 max17042_write_reg(chip->client, MAX17042_DesignCap,
414 max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom,
418 static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
422 vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC);
423 max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
424 max17042_write_verify_reg(chip->client, MAX17042_VFSOC0, vfSoc);
425 max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
428 static void max17042_load_new_capacity_params(struct max17042_chip *chip)
430 u16 full_cap0, rep_cap, dq_acc, vfSoc;
433 struct max17042_config_data *config = chip->pdata->config_data;
435 full_cap0 = max17042_read_reg(chip->client, MAX17042_FullCAP0);
436 vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC);
438 /* fg_vfSoc needs to shifted by 8 bits to get the
439 * perc in 1% accuracy, to get the right rem_cap multiply
440 * full_cap0, fg_vfSoc and devide by 100
442 rem_cap = ((vfSoc >> 8) * full_cap0) / 100;
443 max17042_write_verify_reg(chip->client, MAX17042_RemCap, (u16)rem_cap);
445 rep_cap = (u16)rem_cap;
446 max17042_write_verify_reg(chip->client, MAX17042_RepCap, rep_cap);
448 /* Write dQ_acc to 200% of Capacity and dP_acc to 200% */
449 dq_acc = config->fullcap / dQ_ACC_DIV;
450 max17042_write_verify_reg(chip->client, MAX17042_dQacc, dq_acc);
451 max17042_write_verify_reg(chip->client, MAX17042_dPacc, dP_ACC_200);
453 max17042_write_verify_reg(chip->client, MAX17042_FullCAP,
455 max17042_write_reg(chip->client, MAX17042_DesignCap,
457 max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom,
462 * Block write all the override values coming from platform data.
463 * This function MUST be called before the POR initialization proceedure
464 * specified by maxim.
466 static inline void max17042_override_por_values(struct max17042_chip *chip)
468 struct i2c_client *client = chip->client;
469 struct max17042_config_data *config = chip->pdata->config_data;
471 max17042_override_por(client, MAX17042_TGAIN, config->tgain);
472 max17042_override_por(client, MAx17042_TOFF, config->toff);
473 max17042_override_por(client, MAX17042_CGAIN, config->cgain);
474 max17042_override_por(client, MAX17042_COFF, config->coff);
476 max17042_override_por(client, MAX17042_VALRT_Th, config->valrt_thresh);
477 max17042_override_por(client, MAX17042_TALRT_Th, config->talrt_thresh);
478 max17042_override_por(client, MAX17042_SALRT_Th,
479 config->soc_alrt_thresh);
480 max17042_override_por(client, MAX17042_CONFIG, config->config);
481 max17042_override_por(client, MAX17042_SHDNTIMER, config->shdntimer);
483 max17042_override_por(client, MAX17042_DesignCap, config->design_cap);
484 max17042_override_por(client, MAX17042_ICHGTerm, config->ichgt_term);
486 max17042_override_por(client, MAX17042_AtRate, config->at_rate);
487 max17042_override_por(client, MAX17042_LearnCFG, config->learn_cfg);
488 max17042_override_por(client, MAX17042_FilterCFG, config->filter_cfg);
489 max17042_override_por(client, MAX17042_RelaxCFG, config->relax_cfg);
490 max17042_override_por(client, MAX17042_MiscCFG, config->misc_cfg);
491 max17042_override_por(client, MAX17042_MaskSOC, config->masksoc);
493 max17042_override_por(client, MAX17042_FullCAP, config->fullcap);
494 max17042_override_por(client, MAX17042_FullCAPNom, config->fullcapnom);
495 max17042_override_por(client, MAX17042_SOC_empty, config->socempty);
496 max17042_override_por(client, MAX17042_LAvg_empty, config->lavg_empty);
497 max17042_override_por(client, MAX17042_dQacc, config->dqacc);
498 max17042_override_por(client, MAX17042_dPacc, config->dpacc);
500 max17042_override_por(client, MAX17042_V_empty, config->vempty);
501 max17042_override_por(client, MAX17042_TempNom, config->temp_nom);
502 max17042_override_por(client, MAX17042_TempLim, config->temp_lim);
503 max17042_override_por(client, MAX17042_FCTC, config->fctc);
504 max17042_override_por(client, MAX17042_RCOMP0, config->rcomp0);
505 max17042_override_por(client, MAX17042_TempCo, config->tcompc0);
506 max17042_override_por(client, MAX17042_EmptyTempCo,
507 config->empty_tempco);
508 max17042_override_por(client, MAX17042_K_empty0, config->kempty0);
511 static int max17042_init_chip(struct max17042_chip *chip)
516 max17042_override_por_values(chip);
517 /* After Power up, the MAX17042 requires 500mS in order
518 * to perform signal debouncing and initial SOC reporting
522 /* Initialize configaration */
523 max17042_write_config_regs(chip);
525 /* write cell characterization data */
526 ret = max17042_init_model(chip);
528 dev_err(&chip->client->dev, "%s init failed\n",
532 max17042_verify_model_lock(chip);
534 dev_err(&chip->client->dev, "%s lock verify failed\n",
538 /* write custom parameters */
539 max17042_write_custom_regs(chip);
541 /* update capacity params */
542 max17042_update_capacity_regs(chip);
544 /* delay must be atleast 350mS to allow VFSOC
545 * to be calculated from the new configuration
549 /* reset vfsoc0 reg */
550 max17042_reset_vfsoc0_reg(chip);
552 /* load new capacity params */
553 max17042_load_new_capacity_params(chip);
555 /* Init complete, Clear the POR bit */
556 val = max17042_read_reg(chip->client, MAX17042_STATUS);
557 max17042_write_reg(chip->client, MAX17042_STATUS,
558 val & (~STATUS_POR_BIT));
562 static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off)
566 /* program interrupt thesholds such that we should
567 * get interrupt for every 'off' perc change in the soc
569 soc = max17042_read_reg(chip->client, MAX17042_RepSOC) >> 8;
570 soc_tr = (soc + off) << 8;
571 soc_tr |= (soc - off);
572 max17042_write_reg(chip->client, MAX17042_SALRT_Th, soc_tr);
575 static irqreturn_t max17042_intr_handler(int id, void *dev)
577 return IRQ_WAKE_THREAD;
580 static irqreturn_t max17042_thread_handler(int id, void *dev)
582 struct max17042_chip *chip = dev;
585 val = max17042_read_reg(chip->client, MAX17042_STATUS);
586 if ((val & STATUS_INTR_SOC_BIT) ||
587 (val & STATUS_INTR_LOW_SOC_BIT)) {
588 dev_info(&chip->client->dev, "SOC threshold INTR\n");
589 max17042_set_soc_threshold(chip, 1);
592 power_supply_changed(&chip->battery);
596 static void max17042_init_worker(struct work_struct *work)
598 struct max17042_chip *chip = container_of(work,
599 struct max17042_chip, work);
602 /* Initialize registers according to values from the platform data */
603 if (chip->pdata->enable_por_init && chip->pdata->config_data) {
604 ret = max17042_init_chip(chip);
609 chip->init_complete = 1;
613 static struct max17042_platform_data *
614 max17042_get_pdata(struct device *dev)
616 struct device_node *np = dev->of_node;
618 struct max17042_platform_data *pdata;
621 return dev->platform_data;
623 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
628 * Require current sense resistor value to be specified for
629 * current-sense functionality to be enabled at all.
631 if (of_property_read_u32(np, "maxim,rsns-microohm", &prop) == 0) {
633 pdata->enable_current_sense = true;
639 static struct max17042_platform_data *
640 max17042_get_pdata(struct device *dev)
642 return dev->platform_data;
646 static int __devinit max17042_probe(struct i2c_client *client,
647 const struct i2c_device_id *id)
649 struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
650 struct max17042_chip *chip;
654 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
657 chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
661 chip->client = client;
662 chip->pdata = max17042_get_pdata(&client->dev);
664 dev_err(&client->dev, "no platform data provided\n");
668 i2c_set_clientdata(client, chip);
670 chip->battery.name = "max17042_battery";
671 chip->battery.type = POWER_SUPPLY_TYPE_BATTERY;
672 chip->battery.get_property = max17042_get_property;
673 chip->battery.properties = max17042_battery_props;
674 chip->battery.num_properties = ARRAY_SIZE(max17042_battery_props);
676 /* When current is not measured,
677 * CURRENT_NOW and CURRENT_AVG properties should be invisible. */
678 if (!chip->pdata->enable_current_sense)
679 chip->battery.num_properties -= 2;
681 if (chip->pdata->r_sns == 0)
682 chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;
684 if (chip->pdata->init_data)
685 max17042_set_reg(client, chip->pdata->init_data,
686 chip->pdata->num_init_data);
688 if (!chip->pdata->enable_current_sense) {
689 max17042_write_reg(client, MAX17042_CGAIN, 0x0000);
690 max17042_write_reg(client, MAX17042_MiscCFG, 0x0003);
691 max17042_write_reg(client, MAX17042_LearnCFG, 0x0007);
695 ret = request_threaded_irq(client->irq, max17042_intr_handler,
696 max17042_thread_handler,
697 0, chip->battery.name, chip);
699 reg = max17042_read_reg(client, MAX17042_CONFIG);
700 reg |= CONFIG_ALRT_BIT_ENBL;
701 max17042_write_reg(client, MAX17042_CONFIG, reg);
702 max17042_set_soc_threshold(chip, 1);
704 dev_err(&client->dev, "%s(): cannot get IRQ\n",
708 reg = max17042_read_reg(chip->client, MAX17042_STATUS);
710 if (reg & STATUS_POR_BIT) {
711 INIT_WORK(&chip->work, max17042_init_worker);
712 schedule_work(&chip->work);
714 chip->init_complete = 1;
717 ret = power_supply_register(&client->dev, &chip->battery);
719 dev_err(&client->dev, "failed: power supply register\n");
723 static int __devexit max17042_remove(struct i2c_client *client)
725 struct max17042_chip *chip = i2c_get_clientdata(client);
727 power_supply_unregister(&chip->battery);
732 static const struct of_device_id max17042_dt_match[] = {
733 { .compatible = "maxim,max17042" },
736 MODULE_DEVICE_TABLE(of, max17042_dt_match);
739 static const struct i2c_device_id max17042_id[] = {
743 MODULE_DEVICE_TABLE(i2c, max17042_id);
745 static struct i2c_driver max17042_i2c_driver = {
748 .of_match_table = of_match_ptr(max17042_dt_match),
750 .probe = max17042_probe,
751 .remove = __devexit_p(max17042_remove),
752 .id_table = max17042_id,
754 module_i2c_driver(max17042_i2c_driver);
756 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
757 MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
758 MODULE_LICENSE("GPL");