/* * Fuel gauge driver for Maxim 17042 / 8966 / 8997 * Note that Maxim 8966 and 8997 are mfd and this is its subdevice. * * Copyright (C) 2011 Samsung Electronics * MyungJoo Ham * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * This driver is based on max17040_battery.c */ #include #include #include #include #include #include #include #include #include #include /* Status register bits */ #define STATUS_POR_BIT (1 << 1) #define STATUS_BST_BIT (1 << 3) #define STATUS_VMN_BIT (1 << 8) #define STATUS_TMN_BIT (1 << 9) #define STATUS_SMN_BIT (1 << 10) #define STATUS_BI_BIT (1 << 11) #define STATUS_VMX_BIT (1 << 12) #define STATUS_TMX_BIT (1 << 13) #define STATUS_SMX_BIT (1 << 14) #define STATUS_BR_BIT (1 << 15) /* Interrupt mask bits */ #define CONFIG_ALRT_BIT_ENBL (1 << 2) #define STATUS_INTR_SOCMIN_BIT (1 << 10) #define STATUS_INTR_SOCMAX_BIT (1 << 14) #define VFSOC0_LOCK 0x0000 #define VFSOC0_UNLOCK 0x0080 #define MODEL_UNLOCK1 0X0059 #define MODEL_UNLOCK2 0X00C4 #define MODEL_LOCK1 0X0000 #define MODEL_LOCK2 0X0000 #define dQ_ACC_DIV 0x4 #define dP_ACC_100 0x1900 #define dP_ACC_200 0x3200 struct max17042_chip { struct i2c_client *client; struct power_supply battery; struct max17042_platform_data *pdata; struct work_struct work; int init_complete; }; static int max17042_write_reg(struct i2c_client *client, u8 reg, u16 value) { int ret = i2c_smbus_write_word_data(client, reg, value); if (ret < 0) dev_err(&client->dev, "%s: err %d\n", __func__, ret); return ret; } static int max17042_read_reg(struct i2c_client *client, u8 reg) { int ret = i2c_smbus_read_word_data(client, reg); if (ret < 0) dev_err(&client->dev, "%s: err %d\n", __func__, ret); return ret; } static void max17042_set_reg(struct i2c_client *client, struct max17042_reg_data *data, int size) { int i; for (i = 0; i < size; i++) max17042_write_reg(client, data[i].addr, data[i].data); } static enum power_supply_property max17042_battery_props[] = { POWER_SUPPLY_PROP_PRESENT, POWER_SUPPLY_PROP_CYCLE_COUNT, POWER_SUPPLY_PROP_VOLTAGE_MAX, POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN, POWER_SUPPLY_PROP_VOLTAGE_NOW, POWER_SUPPLY_PROP_VOLTAGE_AVG, POWER_SUPPLY_PROP_CAPACITY, POWER_SUPPLY_PROP_CHARGE_FULL, POWER_SUPPLY_PROP_TEMP, POWER_SUPPLY_PROP_CURRENT_NOW, POWER_SUPPLY_PROP_CURRENT_AVG, }; static int max17042_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { struct max17042_chip *chip = container_of(psy, struct max17042_chip, battery); int ret; if (!chip->init_complete) return -EAGAIN; switch (psp) { case POWER_SUPPLY_PROP_PRESENT: ret = max17042_read_reg(chip->client, MAX17042_STATUS); if (ret < 0) return ret; if (ret & MAX17042_STATUS_BattAbsent) val->intval = 0; else val->intval = 1; break; case POWER_SUPPLY_PROP_CYCLE_COUNT: ret = max17042_read_reg(chip->client, MAX17042_Cycles); if (ret < 0) return ret; val->intval = ret; break; case POWER_SUPPLY_PROP_VOLTAGE_MAX: ret = max17042_read_reg(chip->client, MAX17042_MinMaxVolt); if (ret < 0) return ret; val->intval = ret >> 8; val->intval *= 20000; /* Units of LSB = 20mV */ break; case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN: ret = max17042_read_reg(chip->client, MAX17042_V_empty); if (ret < 0) return ret; val->intval = ret >> 7; val->intval *= 10000; /* Units of LSB = 10mV */ break; case POWER_SUPPLY_PROP_VOLTAGE_NOW: ret = max17042_read_reg(chip->client, MAX17042_VCELL); if (ret < 0) return ret; val->intval = ret * 625 / 8; break; case POWER_SUPPLY_PROP_VOLTAGE_AVG: ret = max17042_read_reg(chip->client, MAX17042_AvgVCELL); if (ret < 0) return ret; val->intval = ret * 625 / 8; break; case POWER_SUPPLY_PROP_CAPACITY: ret = max17042_read_reg(chip->client, MAX17042_RepSOC); if (ret < 0) return ret; val->intval = ret >> 8; break; case POWER_SUPPLY_PROP_CHARGE_FULL: ret = max17042_read_reg(chip->client, MAX17042_FullCAP); if (ret < 0) return ret; val->intval = ret * 1000 / 2; break; case POWER_SUPPLY_PROP_TEMP: ret = max17042_read_reg(chip->client, MAX17042_TEMP); if (ret < 0) return ret; val->intval = ret; /* The value is signed. */ if (val->intval & 0x8000) { val->intval = (0x7fff & ~val->intval) + 1; val->intval *= -1; } /* The value is converted into deci-centigrade scale */ /* Units of LSB = 1 / 256 degree Celsius */ val->intval = val->intval * 10 / 256; break; case POWER_SUPPLY_PROP_CURRENT_NOW: if (chip->pdata->enable_current_sense) { ret = max17042_read_reg(chip->client, MAX17042_Current); if (ret < 0) return ret; val->intval = ret; if (val->intval & 0x8000) { /* Negative */ val->intval = ~val->intval & 0x7fff; val->intval++; val->intval *= -1; } val->intval *= 1562500 / chip->pdata->r_sns; } else { return -EINVAL; } break; case POWER_SUPPLY_PROP_CURRENT_AVG: if (chip->pdata->enable_current_sense) { ret = max17042_read_reg(chip->client, MAX17042_AvgCurrent); if (ret < 0) return ret; val->intval = ret; if (val->intval & 0x8000) { /* Negative */ val->intval = ~val->intval & 0x7fff; val->intval++; val->intval *= -1; } val->intval *= 1562500 / chip->pdata->r_sns; } else { return -EINVAL; } break; default: return -EINVAL; } return 0; } static int max17042_write_verify_reg(struct i2c_client *client, u8 reg, u16 value) { int retries = 8; int ret; u16 read_value; do { ret = i2c_smbus_write_word_data(client, reg, value); read_value = max17042_read_reg(client, reg); if (read_value != value) { ret = -EIO; retries--; } } while (retries && read_value != value); if (ret < 0) dev_err(&client->dev, "%s: err %d\n", __func__, ret); return ret; } static inline void max17042_override_por( struct i2c_client *client, u8 reg, u16 value) { if (value) max17042_write_reg(client, reg, value); } static inline void max10742_unlock_model(struct max17042_chip *chip) { struct i2c_client *client = chip->client; max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_UNLOCK1); max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_UNLOCK2); } static inline void max10742_lock_model(struct max17042_chip *chip) { struct i2c_client *client = chip->client; max17042_write_reg(client, MAX17042_MLOCKReg1, MODEL_LOCK1); max17042_write_reg(client, MAX17042_MLOCKReg2, MODEL_LOCK2); } static inline void max17042_write_model_data(struct max17042_chip *chip, u8 addr, int size) { struct i2c_client *client = chip->client; int i; for (i = 0; i < size; i++) max17042_write_reg(client, addr + i, chip->pdata->config_data->cell_char_tbl[i]); } static inline void max17042_read_model_data(struct max17042_chip *chip, u8 addr, u16 *data, int size) { struct i2c_client *client = chip->client; int i; for (i = 0; i < size; i++) data[i] = max17042_read_reg(client, addr + i); } static inline int max17042_model_data_compare(struct max17042_chip *chip, u16 *data1, u16 *data2, int size) { int i; if (memcmp(data1, data2, size)) { dev_err(&chip->client->dev, "%s compare failed\n", __func__); for (i = 0; i < size; i++) dev_info(&chip->client->dev, "0x%x, 0x%x", data1[i], data2[i]); dev_info(&chip->client->dev, "\n"); return -EINVAL; } return 0; } static int max17042_init_model(struct max17042_chip *chip) { int ret; int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl); u16 *temp_data; temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL); if (!temp_data) return -ENOMEM; max10742_unlock_model(chip); max17042_write_model_data(chip, MAX17042_MODELChrTbl, table_size); max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data, table_size); ret = max17042_model_data_compare( chip, chip->pdata->config_data->cell_char_tbl, temp_data, table_size); max10742_lock_model(chip); kfree(temp_data); return ret; } static int max17042_verify_model_lock(struct max17042_chip *chip) { int i; int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl); u16 *temp_data; int ret = 0; temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL); if (!temp_data) return -ENOMEM; max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data, table_size); for (i = 0; i < table_size; i++) if (temp_data[i]) ret = -EINVAL; kfree(temp_data); return ret; } static void max17042_write_config_regs(struct max17042_chip *chip) { struct max17042_config_data *config = chip->pdata->config_data; max17042_write_reg(chip->client, MAX17042_CONFIG, config->config); max17042_write_reg(chip->client, MAX17042_LearnCFG, config->learn_cfg); max17042_write_reg(chip->client, MAX17042_FilterCFG, config->filter_cfg); max17042_write_reg(chip->client, MAX17042_RelaxCFG, config->relax_cfg); } static void max17042_write_custom_regs(struct max17042_chip *chip) { struct max17042_config_data *config = chip->pdata->config_data; max17042_write_verify_reg(chip->client, MAX17042_RCOMP0, config->rcomp0); max17042_write_verify_reg(chip->client, MAX17042_TempCo, config->tcompc0); max17042_write_reg(chip->client, MAX17042_EmptyTempCo, config->empty_tempco); max17042_write_verify_reg(chip->client, MAX17042_K_empty0, config->kempty0); max17042_write_verify_reg(chip->client, MAX17042_ICHGTerm, config->ichgt_term); } static void max17042_update_capacity_regs(struct max17042_chip *chip) { struct max17042_config_data *config = chip->pdata->config_data; max17042_write_verify_reg(chip->client, MAX17042_FullCAP, config->fullcap); max17042_write_reg(chip->client, MAX17042_DesignCap, config->design_cap); max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom, config->fullcapnom); } static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip) { u16 vfSoc; vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC); max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK); max17042_write_verify_reg(chip->client, MAX17042_VFSOC0, vfSoc); max17042_write_reg(chip->client, MAX17042_VFSOC0Enable, VFSOC0_LOCK); } static void max17042_load_new_capacity_params(struct max17042_chip *chip) { u16 full_cap0, rep_cap, dq_acc, vfSoc; u32 rem_cap; struct max17042_config_data *config = chip->pdata->config_data; full_cap0 = max17042_read_reg(chip->client, MAX17042_FullCAP0); vfSoc = max17042_read_reg(chip->client, MAX17042_VFSOC); /* fg_vfSoc needs to shifted by 8 bits to get the * perc in 1% accuracy, to get the right rem_cap multiply * full_cap0, fg_vfSoc and devide by 100 */ rem_cap = ((vfSoc >> 8) * full_cap0) / 100; max17042_write_verify_reg(chip->client, MAX17042_RemCap, (u16)rem_cap); rep_cap = (u16)rem_cap; max17042_write_verify_reg(chip->client, MAX17042_RepCap, rep_cap); /* Write dQ_acc to 200% of Capacity and dP_acc to 200% */ dq_acc = config->fullcap / dQ_ACC_DIV; max17042_write_verify_reg(chip->client, MAX17042_dQacc, dq_acc); max17042_write_verify_reg(chip->client, MAX17042_dPacc, dP_ACC_200); max17042_write_verify_reg(chip->client, MAX17042_FullCAP, config->fullcap); max17042_write_reg(chip->client, MAX17042_DesignCap, config->design_cap); max17042_write_verify_reg(chip->client, MAX17042_FullCAPNom, config->fullcapnom); } /* * Block write all the override values coming from platform data. * This function MUST be called before the POR initialization proceedure * specified by maxim. */ static inline void max17042_override_por_values(struct max17042_chip *chip) { struct i2c_client *client = chip->client; struct max17042_config_data *config = chip->pdata->config_data; max17042_override_por(client, MAX17042_TGAIN, config->tgain); max17042_override_por(client, MAx17042_TOFF, config->toff); max17042_override_por(client, MAX17042_CGAIN, config->cgain); max17042_override_por(client, MAX17042_COFF, config->coff); max17042_override_por(client, MAX17042_VALRT_Th, config->valrt_thresh); max17042_override_por(client, MAX17042_TALRT_Th, config->talrt_thresh); max17042_override_por(client, MAX17042_SALRT_Th, config->soc_alrt_thresh); max17042_override_por(client, MAX17042_CONFIG, config->config); max17042_override_por(client, MAX17042_SHDNTIMER, config->shdntimer); max17042_override_por(client, MAX17042_DesignCap, config->design_cap); max17042_override_por(client, MAX17042_ICHGTerm, config->ichgt_term); max17042_override_por(client, MAX17042_AtRate, config->at_rate); max17042_override_por(client, MAX17042_LearnCFG, config->learn_cfg); max17042_override_por(client, MAX17042_FilterCFG, config->filter_cfg); max17042_override_por(client, MAX17042_RelaxCFG, config->relax_cfg); max17042_override_por(client, MAX17042_MiscCFG, config->misc_cfg); max17042_override_por(client, MAX17042_MaskSOC, config->masksoc); max17042_override_por(client, MAX17042_FullCAP, config->fullcap); max17042_override_por(client, MAX17042_FullCAPNom, config->fullcapnom); max17042_override_por(client, MAX17042_SOC_empty, config->socempty); max17042_override_por(client, MAX17042_LAvg_empty, config->lavg_empty); max17042_override_por(client, MAX17042_dQacc, config->dqacc); max17042_override_por(client, MAX17042_dPacc, config->dpacc); max17042_override_por(client, MAX17042_V_empty, config->vempty); max17042_override_por(client, MAX17042_TempNom, config->temp_nom); max17042_override_por(client, MAX17042_TempLim, config->temp_lim); max17042_override_por(client, MAX17042_FCTC, config->fctc); max17042_override_por(client, MAX17042_RCOMP0, config->rcomp0); max17042_override_por(client, MAX17042_TempCo, config->tcompc0); max17042_override_por(client, MAX17042_EmptyTempCo, config->empty_tempco); max17042_override_por(client, MAX17042_K_empty0, config->kempty0); } static int max17042_init_chip(struct max17042_chip *chip) { int ret; int val; max17042_override_por_values(chip); /* After Power up, the MAX17042 requires 500mS in order * to perform signal debouncing and initial SOC reporting */ msleep(500); /* Initialize configaration */ max17042_write_config_regs(chip); /* write cell characterization data */ ret = max17042_init_model(chip); if (ret) { dev_err(&chip->client->dev, "%s init failed\n", __func__); return -EIO; } max17042_verify_model_lock(chip); if (ret) { dev_err(&chip->client->dev, "%s lock verify failed\n", __func__); return -EIO; } /* write custom parameters */ max17042_write_custom_regs(chip); /* update capacity params */ max17042_update_capacity_regs(chip); /* delay must be atleast 350mS to allow VFSOC * to be calculated from the new configuration */ msleep(350); /* reset vfsoc0 reg */ max17042_reset_vfsoc0_reg(chip); /* load new capacity params */ max17042_load_new_capacity_params(chip); /* Init complete, Clear the POR bit */ val = max17042_read_reg(chip->client, MAX17042_STATUS); max17042_write_reg(chip->client, MAX17042_STATUS, val & (~STATUS_POR_BIT)); return 0; } static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off) { u16 soc, soc_tr; /* program interrupt thesholds such that we should * get interrupt for every 'off' perc change in the soc */ soc = max17042_read_reg(chip->client, MAX17042_RepSOC) >> 8; soc_tr = (soc + off) << 8; soc_tr |= (soc - off); max17042_write_reg(chip->client, MAX17042_SALRT_Th, soc_tr); } static irqreturn_t max17042_thread_handler(int id, void *dev) { struct max17042_chip *chip = dev; u16 val; val = max17042_read_reg(chip->client, MAX17042_STATUS); if ((val & STATUS_INTR_SOCMIN_BIT) || (val & STATUS_INTR_SOCMAX_BIT)) { dev_info(&chip->client->dev, "SOC threshold INTR\n"); max17042_set_soc_threshold(chip, 1); } power_supply_changed(&chip->battery); return IRQ_HANDLED; } static void max17042_init_worker(struct work_struct *work) { struct max17042_chip *chip = container_of(work, struct max17042_chip, work); int ret; /* Initialize registers according to values from the platform data */ if (chip->pdata->enable_por_init && chip->pdata->config_data) { ret = max17042_init_chip(chip); if (ret) return; } chip->init_complete = 1; } #ifdef CONFIG_OF static struct max17042_platform_data * max17042_get_pdata(struct device *dev) { struct device_node *np = dev->of_node; u32 prop; struct max17042_platform_data *pdata; if (!np) return dev->platform_data; pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); if (!pdata) return NULL; /* * Require current sense resistor value to be specified for * current-sense functionality to be enabled at all. */ if (of_property_read_u32(np, "maxim,rsns-microohm", &prop) == 0) { pdata->r_sns = prop; pdata->enable_current_sense = true; } return pdata; } #else static struct max17042_platform_data * max17042_get_pdata(struct device *dev) { return dev->platform_data; } #endif static int __devinit max17042_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent); struct max17042_chip *chip; int ret; int reg; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) return -EIO; chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; chip->client = client; chip->pdata = max17042_get_pdata(&client->dev); if (!chip->pdata) { dev_err(&client->dev, "no platform data provided\n"); return -EINVAL; } i2c_set_clientdata(client, chip); chip->battery.name = "max17042_battery"; chip->battery.type = POWER_SUPPLY_TYPE_BATTERY; chip->battery.get_property = max17042_get_property; chip->battery.properties = max17042_battery_props; chip->battery.num_properties = ARRAY_SIZE(max17042_battery_props); /* When current is not measured, * CURRENT_NOW and CURRENT_AVG properties should be invisible. */ if (!chip->pdata->enable_current_sense) chip->battery.num_properties -= 2; if (chip->pdata->r_sns == 0) chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR; if (chip->pdata->init_data) max17042_set_reg(client, chip->pdata->init_data, chip->pdata->num_init_data); if (!chip->pdata->enable_current_sense) { max17042_write_reg(client, MAX17042_CGAIN, 0x0000); max17042_write_reg(client, MAX17042_MiscCFG, 0x0003); max17042_write_reg(client, MAX17042_LearnCFG, 0x0007); } if (client->irq) { ret = request_threaded_irq(client->irq, NULL, max17042_thread_handler, IRQF_TRIGGER_FALLING, chip->battery.name, chip); if (!ret) { reg = max17042_read_reg(client, MAX17042_CONFIG); reg |= CONFIG_ALRT_BIT_ENBL; max17042_write_reg(client, MAX17042_CONFIG, reg); max17042_set_soc_threshold(chip, 1); } else dev_err(&client->dev, "%s(): cannot get IRQ\n", __func__); } reg = max17042_read_reg(chip->client, MAX17042_STATUS); if (reg & STATUS_POR_BIT) { INIT_WORK(&chip->work, max17042_init_worker); schedule_work(&chip->work); } else { chip->init_complete = 1; } ret = power_supply_register(&client->dev, &chip->battery); if (ret) dev_err(&client->dev, "failed: power supply register\n"); return ret; } static int __devexit max17042_remove(struct i2c_client *client) { struct max17042_chip *chip = i2c_get_clientdata(client); power_supply_unregister(&chip->battery); return 0; } #ifdef CONFIG_OF static const struct of_device_id max17042_dt_match[] = { { .compatible = "maxim,max17042" }, { }, }; MODULE_DEVICE_TABLE(of, max17042_dt_match); #endif static const struct i2c_device_id max17042_id[] = { { "max17042", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, max17042_id); static struct i2c_driver max17042_i2c_driver = { .driver = { .name = "max17042", .of_match_table = of_match_ptr(max17042_dt_match), }, .probe = max17042_probe, .remove = __devexit_p(max17042_remove), .id_table = max17042_id, }; module_i2c_driver(max17042_i2c_driver); MODULE_AUTHOR("MyungJoo Ham "); MODULE_DESCRIPTION("MAX17042 Fuel Gauge"); MODULE_LICENSE("GPL");