/* * Copyright (C) ST-Ericsson SA 2011 * * Battery temperature driver for ab5500 * * License Terms: GNU General Public License v2 * Authors: * Johan Palsson * Karl Komierowski */ #include #include #include #include #include #include #include #include #include #include #include #include #include #define BTEMP_THERMAL_LOW_LIMIT -10 #define BTEMP_THERMAL_MED_LIMIT 0 #define BTEMP_THERMAL_HIGH_LIMIT_62 62 #define BTEMP_BATCTRL_CURR_SRC_7UA 7 #define BTEMP_BATCTRL_CURR_SRC_15UA 15 #define BTEMP_BATCTRL_CURR_SRC_20UA 20 #define UART_MODE 0x0F #define BAT_CUR_SRC 0x1F #define RESIS_ID_MODE 0x03 #define RESET 0x00 #define ADOUT_10K_PULL_UP 0x07 #define to_ab5500_btemp_device_info(x) container_of((x), \ struct ab5500_btemp, btemp_psy); /** * struct ab5500_btemp_interrupts - ab5500 interrupts * @name: name of the interrupt * @isr function pointer to the isr */ struct ab5500_btemp_interrupts { char *name; irqreturn_t (*isr)(int irq, void *data); }; struct ab5500_btemp_events { bool batt_rem; bool usb_conn; }; /** * struct ab5500_btemp - ab5500 BTEMP device information * @dev: Pointer to the structure device * @chip_id: Chip-Id of the AB5500 * @curr_source: What current source we use, in uA * @bat_temp: Battery temperature in degree Celcius * @prev_bat_temp Last dispatched battery temperature * @node: struct of type list_head * @parent: Pointer to the struct ab5500 * @gpadc: Pointer to the struct gpadc * @gpadc-auto: Pointer to the struct adc_auto_input * @pdata: Pointer to the ab5500_btemp platform data * @bat: Pointer to the ab5500_bm platform data * @btemp_psy: Structure for BTEMP specific battery properties * @events: Structure for information about events triggered * @btemp_wq: Work queue for measuring the temperature periodically * @btemp_periodic_work: Work for measuring the temperature periodically */ struct ab5500_btemp { struct device *dev; u8 chip_id; int curr_source; int bat_temp; int prev_bat_temp; struct list_head node; struct ab5500 *parent; struct ab5500_gpadc *gpadc; struct adc_auto_input *gpadc_auto; struct abx500_btemp_platform_data *pdata; struct abx500_bm_data *bat; struct power_supply btemp_psy; struct ab5500_btemp_events events; struct workqueue_struct *btemp_wq; struct delayed_work btemp_periodic_work; }; /* BTEMP power supply properties */ static enum power_supply_property ab5500_btemp_props[] = { POWER_SUPPLY_PROP_PRESENT, POWER_SUPPLY_PROP_ONLINE, POWER_SUPPLY_PROP_TECHNOLOGY, POWER_SUPPLY_PROP_TEMP, }; static LIST_HEAD(ab5500_btemp_list); struct ab5500_btemp *ab5500_btemp_get(void) { struct ab5500_btemp *di; di = list_first_entry(&ab5500_btemp_list, struct ab5500_btemp, node); return di; } /** * ab5500_btemp_batctrl_volt_to_res() - convert batctrl voltage to resistance * @di: pointer to the ab5500_btemp structure * @v_batctrl: measured batctrl voltage * * This function returns the battery resistance that is * derived from the BATCTRL voltage. * Returns value in Ohms. */ static int ab5500_btemp_batctrl_volt_to_res(struct ab5500_btemp *di, int v_batctrl) { int rbs; if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL) { /* * If the battery has internal NTC, we use the current * source to calculate the resistance, 7uA or 20uA */ rbs = v_batctrl * 1000 / di->curr_source; } else { /* * BAT_CTRL is internally * connected to 1.8V through a 10k resistor */ rbs = (10000 * (v_batctrl)) / (1800 - v_batctrl); } return rbs; } /** * ab5500_btemp_read_batctrl_voltage() - measure batctrl voltage * @di: pointer to the ab5500_btemp structure * * This function returns the voltage on BATCTRL. Returns value in mV. */ static int ab5500_btemp_read_batctrl_voltage(struct ab5500_btemp *di) { int vbtemp; static int prev; vbtemp = ab5500_gpadc_convert(di->gpadc, BAT_CTRL); if (vbtemp < 0) { dev_err(di->dev, "%s gpadc conversion failed, using previous value", __func__); return prev; } prev = vbtemp; return vbtemp; } /** * ab5500_btemp_curr_source_enable() - enable/disable batctrl current source * @di: pointer to the ab5500_btemp structure * @enable: enable or disable the current source * * Enable or disable the current sources for the BatCtrl AD channel */ static int ab5500_btemp_curr_source_enable(struct ab5500_btemp *di, bool enable) { int ret = 0; /* Only do this for batteries with internal NTC */ if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && enable) { dev_dbg(di->dev, "Set BATCTRL %duA\n", di->curr_source); ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_UART, UART_MODE, RESIS_ID_MODE); if (ret) { dev_err(di->dev, "%s failed setting resistance identification mode\n", __func__); return ret; } ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_URI, BAT_CUR_SRC, BAT_CTRL_15U_ENA); if (ret) { dev_err(di->dev, "%s failed enabling current source\n", __func__); goto disable_curr_source; } } else if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && !enable) { dev_dbg(di->dev, "Disable BATCTRL curr source\n"); /* Write 0 to the curr bits */ ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_URI, BAT_CUR_SRC, RESET); if (ret) { dev_err(di->dev, "%s failed disabling current source\n", __func__); goto disable_curr_source; } ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_UART, UART_MODE, RESET); if (ret) { dev_err(di->dev, "%s failed disabling force comp\n", __func__); } } return ret; disable_curr_source: /* Write 0 to the curr bits */ ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_URI, BAT_CUR_SRC, RESET); if (ret) { dev_err(di->dev, "%s failed disabling current source\n", __func__); } return ret; } /** * ab5500_btemp_get_batctrl_res() - get battery resistance * @di: pointer to the ab5500_btemp structure * * This function returns the battery pack identification resistance. * Returns value in Ohms. */ static int ab5500_btemp_get_batctrl_res(struct ab5500_btemp *di) { int ret; int batctrl; int res; ret = ab5500_btemp_curr_source_enable(di, true); /* TODO: This delay has to be optimised */ mdelay(1000); if (ret) { dev_err(di->dev, "%s curr source enable failed\n", __func__); return ret; } batctrl = ab5500_btemp_read_batctrl_voltage(di); res = ab5500_btemp_batctrl_volt_to_res(di, batctrl); ret = ab5500_btemp_curr_source_enable(di, false); if (ret) { dev_err(di->dev, "%s curr source disable failed\n", __func__); return ret; } dev_dbg(di->dev, "%s batctrl: %d res: %d ", __func__, batctrl, res); return res; } /** * ab5500_btemp_res_to_temp() - resistance to temperature * @di: pointer to the ab5500_btemp structure * @tbl: pointer to the resiatance to temperature table * @tbl_size: size of the resistance to temperature table * @res: resistance to calculate the temperature from * * This function returns the battery temperature in degrees Celcius * based on the NTC resistance. */ static int ab5500_btemp_res_to_temp(struct ab5500_btemp *di, const struct abx500_res_to_temp *tbl, int tbl_size, int res) { int i, temp; /* * Calculate the formula for the straight line * Simple interpolation if we are within * the resistance table limits, extrapolate * if resistance is outside the limits. */ if (res > tbl[0].resist) i = 0; else if (res <= tbl[tbl_size - 1].resist) i = tbl_size - 2; else { i = 0; while (!(res <= tbl[i].resist && res > tbl[i + 1].resist)) i++; } temp = tbl[i].temp + ((tbl[i + 1].temp - tbl[i].temp) * (res - tbl[i].resist)) / (tbl[i + 1].resist - tbl[i].resist); return temp; } /** * ab5500_btemp_measure_temp() - measure battery temperature * @di: pointer to the ab5500_btemp structure * * Returns battery temperature (on success) else the previous temperature */ static int ab5500_btemp_measure_temp(struct ab5500_btemp *di) { int temp, ret; static int prev; int rbat, vntc; int rntc = 0; u8 id; id = di->bat->batt_id; if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && id != BATTERY_UNKNOWN) { rbat = ab5500_btemp_get_batctrl_res(di); if (rbat < 0) { dev_err(di->dev, "%s get batctrl res failed\n", __func__); /* * Return out-of-range temperature so that * charging is stopped */ return BTEMP_THERMAL_LOW_LIMIT; } temp = ab5500_btemp_res_to_temp(di, di->bat->bat_type[id].r_to_t_tbl, di->bat->bat_type[id].n_temp_tbl_elements, rbat); } else { ret = abx500_mask_and_set_register_interruptible(di->dev, AB5500_BANK_FG_BATTCOM_ACC, AB5500_UART, UART_MODE, ADOUT_10K_PULL_UP); if (ret) { dev_err(di->dev, "failed to enable 10k pull up to Vadout\n"); } vntc = ab5500_gpadc_convert(di->gpadc, BTEMP_BALL); if (vntc < 0) { dev_err(di->dev, "%s gpadc conversion failed," " using previous value\n", __func__); return prev; } /* * The PCB NTC is sourced from 2.75v via a 10kOhm * resistor. */ rntc = 10000 * vntc / (27500 - vntc); temp = ab5500_btemp_res_to_temp(di, di->bat->bat_type[id].r_to_t_tbl, di->bat->bat_type[id].n_temp_tbl_elements, rntc); prev = temp; } dev_dbg(di->dev, "Battery temperature is %d\n", temp); return temp; } /** * ab5500_btemp_id() - Identify the connected battery * @di: pointer to the ab5500_btemp structure * * This function will try to identify the battery by reading the ID * resistor. Some brands use a combined ID resistor with a NTC resistor to * both be able to identify and to read the temperature of it. */ static int ab5500_btemp_id(struct ab5500_btemp *di) { int res; u8 i; di->curr_source = BTEMP_BATCTRL_CURR_SRC_7UA; di->bat->batt_id = BATTERY_UNKNOWN; res = ab5500_btemp_get_batctrl_res(di); if (res < 0) { dev_err(di->dev, "%s get batctrl res failed\n", __func__); return -ENXIO; } /* BATTERY_UNKNOWN is defined on position 0, skip it! */ for (i = BATTERY_UNKNOWN + 1; i < di->bat->n_btypes; i++) { if ((res <= di->bat->bat_type[i].resis_high) && (res >= di->bat->bat_type[i].resis_low)) { dev_dbg(di->dev, "Battery detected on %s" " low %d < res %d < high: %d" " index: %d\n", di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL ? "BATCTRL" : "BATTEMP", di->bat->bat_type[i].resis_low, res, di->bat->bat_type[i].resis_high, i); di->bat->batt_id = i; break; } } if (di->bat->batt_id == BATTERY_UNKNOWN) { dev_warn(di->dev, "Battery identified as unknown" ", resistance %d Ohm\n", res); return -ENXIO; } /* * We only have to change current source if the * detected type is Type 1, else we use the 7uA source */ if (di->bat->adc_therm == ABx500_ADC_THERM_BATCTRL && di->bat->batt_id == 1) { dev_dbg(di->dev, "Set BATCTRL current source to 15uA\n"); di->curr_source = BTEMP_BATCTRL_CURR_SRC_15UA; } return di->bat->batt_id; } /** * ab5500_btemp_periodic_work() - Measuring the temperature periodically * @work: pointer to the work_struct structure * * Work function for measuring the temperature periodically */ static void ab5500_btemp_periodic_work(struct work_struct *work) { struct ab5500_btemp *di = container_of(work, struct ab5500_btemp, btemp_periodic_work.work); di->bat_temp = ab5500_btemp_measure_temp(di); if (di->bat_temp != di->prev_bat_temp) { di->prev_bat_temp = di->bat_temp; power_supply_changed(&di->btemp_psy); } di->bat->temp_now = di->bat_temp; /* Schedule a new measurement */ queue_delayed_work(di->btemp_wq, &di->btemp_periodic_work, round_jiffies(20 * HZ)); } /** * ab5500_btemp_batt_removal_handler() - battery removal detected * @irq: interrupt number * @_di: void pointer that has to address of ab5500_btemp * * Returns IRQ status(IRQ_HANDLED) */ static irqreturn_t ab5500_btemp_batt_removal_handler(int irq, void *_di) { struct ab5500_btemp *di = _di; dev_err(di->dev, "Battery removal detected!\n"); di->events.batt_rem = true; power_supply_changed(&di->btemp_psy); return IRQ_HANDLED; } /** * ab5500_btemp_batt_attach_handler() - battery insertion detected * @irq: interrupt number * @_di: void pointer that has to address of ab5500_btemp * * Returns IRQ status(IRQ_HANDLED) */ static irqreturn_t ab5500_btemp_batt_attach_handler(int irq, void *_di) { struct ab5500_btemp *di = _di; dev_err(di->dev, "Battery attached!\n"); di->events.batt_rem = false; power_supply_changed(&di->btemp_psy); return IRQ_HANDLED; } /** * ab5500_btemp_periodic() - Periodic temperature measurements * @di: pointer to the ab5500_btemp structure * @enable: enable or disable periodic temperature measurements * * Starts of stops periodic temperature measurements. Periodic measurements * should only be done when a charger is connected. */ static void ab5500_btemp_periodic(struct ab5500_btemp *di, bool enable) { dev_dbg(di->dev, "Enable periodic temperature measurements: %d\n", enable); if (enable) queue_delayed_work(di->btemp_wq, &di->btemp_periodic_work, 0); else cancel_delayed_work_sync(&di->btemp_periodic_work); } /** * ab5500_btemp_get_property() - get the btemp properties * @psy: pointer to the power_supply structure * @psp: pointer to the power_supply_property structure * @val: pointer to the power_supply_propval union * * This function gets called when an application tries to get the btemp * properties by reading the sysfs files. * online: presence of the battery * present: presence of the battery * technology: battery technology * temp: battery temperature * Returns error code in case of failure else 0(on success) */ static int ab5500_btemp_get_property(struct power_supply *psy, enum power_supply_property psp, union power_supply_propval *val) { struct ab5500_btemp *di; di = to_ab5500_btemp_device_info(psy); switch (psp) { case POWER_SUPPLY_PROP_PRESENT: case POWER_SUPPLY_PROP_ONLINE: if (di->events.batt_rem) val->intval = 0; else val->intval = 1; break; case POWER_SUPPLY_PROP_TECHNOLOGY: val->intval = di->bat->bat_type[di->bat->batt_id].name; break; case POWER_SUPPLY_PROP_TEMP: if (di->bat->batt_id == BATTERY_UNKNOWN) /* * In case the battery is not identified, its assumed that * we are using the power supply and since no monitoring is * done for the same, a nominal temp is hardocded. */ val->intval = 250; else val->intval = di->bat_temp * 10; break; default: return -EINVAL; } return 0; } static int ab5500_btemp_get_ext_psy_data(struct device *dev, void *data) { struct power_supply *psy; struct power_supply *ext; struct ab5500_btemp *di; union power_supply_propval ret; int i, j; bool psy_found = false; psy = (struct power_supply *)data; ext = dev_get_drvdata(dev); di = to_ab5500_btemp_device_info(psy); /* * For all psy where the name of your driver * appears in any supplied_to */ for (i = 0; i < ext->num_supplicants; i++) { if (!strcmp(ext->supplied_to[i], psy->name)) psy_found = true; } if (!psy_found) return 0; /* Go through all properties for the psy */ for (j = 0; j < ext->num_properties; j++) { enum power_supply_property prop; prop = ext->properties[j]; if (ext->get_property(ext, prop, &ret)) continue; switch (prop) { case POWER_SUPPLY_PROP_PRESENT: switch (ext->type) { case POWER_SUPPLY_TYPE_USB: /* USB disconnected */ if (!ret.intval && di->events.usb_conn) { di->events.usb_conn = false; ab5500_btemp_periodic(di, false); } /* USB connected */ else if (ret.intval && !di->events.usb_conn) { di->events.usb_conn = true; ab5500_btemp_periodic(di, true); } break; default: break; } break; default: break; } } return 0; } /** * ab5500_btemp_external_power_changed() - callback for power supply changes * @psy: pointer to the structure power_supply * * This function is pointing to the function pointer external_power_changed * of the structure power_supply. * This function gets executed when there is a change in the external power * supply to the btemp. */ static void ab5500_btemp_external_power_changed(struct power_supply *psy) { struct ab5500_btemp *di = to_ab5500_btemp_device_info(psy); class_for_each_device(power_supply_class, NULL, &di->btemp_psy, ab5500_btemp_get_ext_psy_data); } /* ab5500 btemp driver interrupts and their respective isr */ static struct ab5500_btemp_interrupts ab5500_btemp_irq[] = { {"BATT_REMOVAL", ab5500_btemp_batt_removal_handler}, {"BATT_ATTACH", ab5500_btemp_batt_attach_handler}, }; static int ab5500_btemp_bat_temp_trig(int mux) { struct ab5500_btemp *di = ab5500_btemp_get(); if (di->bat_temp < BTEMP_THERMAL_LOW_LIMIT) { dev_err(di->dev, "battery temp less than lower threshold (-10 deg cel)\n"); power_supply_changed(&di->btemp_psy); } else if (di->bat_temp > BTEMP_THERMAL_HIGH_LIMIT_62) { dev_err(di->dev, "battery temp greater them max threshold\n"); power_supply_changed(&di->btemp_psy); } return 0;; } static int ab5500_btemp_auto_temp(struct ab5500_btemp *di) { struct adc_auto_input *auto_ip; int ret = 0; auto_ip = kzalloc(sizeof(struct adc_auto_input), GFP_KERNEL); if (!auto_ip) { dev_err(di->dev, "failed to allocate memory\n"); return -ENOMEM; } auto_ip->mux = BTEMP_BALL; auto_ip->freq = MS500; auto_ip->min = BTEMP_THERMAL_LOW_LIMIT; auto_ip->max = BTEMP_THERMAL_HIGH_LIMIT_62; auto_ip->auto_adc_callback = ab5500_btemp_bat_temp_trig; di->gpadc_auto = auto_ip; ret = ab5500_gpadc_convert_auto(di->gpadc, di->gpadc_auto); if (ret) dev_err(di->dev, "failed to set auto trigger for battery temp\n"); return ret; } #if defined(CONFIG_PM) static int ab5500_btemp_resume(struct platform_device *pdev) { struct ab5500_btemp *di = platform_get_drvdata(pdev); if (di->events.usb_conn) ab5500_btemp_periodic(di, true); return 0; } static int ab5500_btemp_suspend(struct platform_device *pdev, pm_message_t state) { struct ab5500_btemp *di = platform_get_drvdata(pdev); if (di->events.usb_conn) ab5500_btemp_periodic(di, false); return 0; } #else #define ab5500_btemp_suspend NULL #define ab5500_btemp_resume NULL #endif static int __devexit ab5500_btemp_remove(struct platform_device *pdev) { struct ab5500_btemp *di = platform_get_drvdata(pdev); int i, irq; /* Disable interrupts */ for (i = 0; i < ARRAY_SIZE(ab5500_btemp_irq); i++) { irq = platform_get_irq_byname(pdev, ab5500_btemp_irq[i].name); free_irq(irq, di); } /* Delete the work queue */ destroy_workqueue(di->btemp_wq); flush_scheduled_work(); power_supply_unregister(&di->btemp_psy); platform_set_drvdata(pdev, NULL); kfree(di->gpadc_auto); kfree(di); return 0; } static int __devinit ab5500_btemp_probe(struct platform_device *pdev) { int irq, i, ret = 0; struct abx500_bm_plat_data *plat_data; struct ab5500_btemp *di = kzalloc(sizeof(struct ab5500_btemp), GFP_KERNEL); if (!di) return -ENOMEM; /* get parent data */ di->dev = &pdev->dev; di->parent = dev_get_drvdata(pdev->dev.parent); di->gpadc = ab5500_gpadc_get("ab5500-adc.0"); plat_data = pdev->dev.platform_data; di->pdata = plat_data->btemp; di->bat = plat_data->battery; /* get btemp specific platform data */ if (!di->pdata) { dev_err(di->dev, "no btemp platform data supplied\n"); ret = -EINVAL; goto free_device_info; } /* get battery specific platform data */ if (!di->bat) { dev_err(di->dev, "no battery platform data supplied\n"); ret = -EINVAL; goto free_device_info; } /* BTEMP supply */ di->btemp_psy.name = "ab5500_btemp"; di->btemp_psy.type = POWER_SUPPLY_TYPE_BATTERY; di->btemp_psy.properties = ab5500_btemp_props; di->btemp_psy.num_properties = ARRAY_SIZE(ab5500_btemp_props); di->btemp_psy.get_property = ab5500_btemp_get_property; di->btemp_psy.supplied_to = di->pdata->supplied_to; di->btemp_psy.num_supplicants = di->pdata->num_supplicants; di->btemp_psy.external_power_changed = ab5500_btemp_external_power_changed; /* Create a work queue for the btemp */ di->btemp_wq = create_singlethread_workqueue("ab5500_btemp_wq"); if (di->btemp_wq == NULL) { dev_err(di->dev, "failed to create work queue\n"); goto free_device_info; } /* Init work for measuring temperature periodically */ INIT_DELAYED_WORK_DEFERRABLE(&di->btemp_periodic_work, ab5500_btemp_periodic_work); /* Get Chip ID of the ABB ASIC */ ret = abx500_get_chip_id(di->dev); if (ret < 0) { dev_err(di->dev, "failed to get chip ID\n"); goto free_btemp_wq; } di->chip_id = ret; dev_dbg(di->dev, "ab5500 CID is: 0x%02x\n", di->chip_id); /* Identify the battery */ if (ab5500_btemp_id(di) < 0) dev_warn(di->dev, "failed to identify the battery\n"); /* Measure temperature once initially */ di->bat_temp = ab5500_btemp_measure_temp(di); di->bat->temp_now = di->bat_temp; /* Register BTEMP power supply class */ ret = power_supply_register(di->dev, &di->btemp_psy); if (ret) { dev_err(di->dev, "failed to register BTEMP psy\n"); goto free_btemp_wq; } /* Register interrupts */ for (i = 0; i < ARRAY_SIZE(ab5500_btemp_irq); i++) { irq = platform_get_irq_byname(pdev, ab5500_btemp_irq[i].name); ret = request_threaded_irq(irq, NULL, ab5500_btemp_irq[i].isr, IRQF_SHARED | IRQF_NO_SUSPEND, ab5500_btemp_irq[i].name, di); if (ret) { dev_err(di->dev, "failed to request %s IRQ %d: %d\n" , ab5500_btemp_irq[i].name, irq, ret); goto free_irq; } dev_dbg(di->dev, "Requested %s IRQ %d: %d\n", ab5500_btemp_irq[i].name, irq, ret); } ret = ab5500_btemp_auto_temp(di); if (ret) { dev_err(di->dev, "failed to register auto trigger for battery temp\n"); goto free_irq; } platform_set_drvdata(pdev, di); dev_info(di->dev, "probe success\n"); return ret; free_irq: power_supply_unregister(&di->btemp_psy); /* We also have to free all successfully registered irqs */ for (i = i - 1; i >= 0; i--) { irq = platform_get_irq_byname(pdev, ab5500_btemp_irq[i].name); free_irq(irq, di); } free_btemp_wq: destroy_workqueue(di->btemp_wq); free_device_info: kfree(di); return ret; } static struct platform_driver ab5500_btemp_driver = { .probe = ab5500_btemp_probe, .remove = __devexit_p(ab5500_btemp_remove), .suspend = ab5500_btemp_suspend, .resume = ab5500_btemp_resume, .driver = { .name = "ab5500-btemp", .owner = THIS_MODULE, }, }; static int __init ab5500_btemp_init(void) { return platform_driver_register(&ab5500_btemp_driver); } static void __exit ab5500_btemp_exit(void) { platform_driver_unregister(&ab5500_btemp_driver); } subsys_initcall_sync(ab5500_btemp_init); module_exit(ab5500_btemp_exit); MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Johan Palsson, Karl Komierowski"); MODULE_ALIAS("platform:ab5500-btemp"); MODULE_DESCRIPTION("AB5500 battery temperature driver");