高通电源管理qpnp-vm-bms驱动
- 2019 年 10 月 11 日
- 笔记
1. compatible节点：
qpnp-vm-bms.c使用来控制电池曲线的和BMS功能的，其compatible节点是"qcom,qpnp-vm-bms"
2. probe函数：
qpnp_vm_bms_probe函数如下：
static int qpnp_vm_bms_probe(struct spmi_device *spmi) { struct qpnp_bms_chip *chip; struct device_node *revid_dev_node; int rc, vbatt = 0; chip = devm_kzalloc(&spmi->dev, sizeof(*chip), GFP_KERNEL); if (!chip) { pr_err("kzalloc() failed.n"); return -ENOMEM; } //获取ADC的值，ADC是电流的大小，绑定vadc，并且获取温度，设备列表 rc = bms_get_adc(chip, spmi); if (rc < 0) { pr_err("Failed to get adc rc=%dn", rc); return rc; } //指向revision外围节点的phandle，vm-bus需要配置这个节点 revid_dev_node = of_parse_phandle(spmi->dev.of_node, "qcom,pmic-revid", 0); if (!revid_dev_node) { pr_err("Missing qcom,pmic-revid propertyn"); return -EINVAL; } //返回pmic的修订信息 chip->revid_data = get_revid_data(revid_dev_node); if (IS_ERR(chip->revid_data)) { pr_err("revid error rc = %ldn", PTR_ERR(chip->revid_data)); return -EINVAL; } if ((chip->revid_data->pmic_subtype == PM8916_V2P0_SUBTYPE) && chip->revid_data->rev4 == PM8916_V2P0_REV4) chip->workaround_flag |= WRKARND_PON_OCV_COMP; //查看是否是热启动的，热启动就是在不关闭设备的情况下，重启电脑 rc = qpnp_pon_is_warm_reset(); if (rc < 0) { pr_err("Error reading warm reset status rc=%dn", rc); return rc; } chip->warm_reset = !!rc; //解析spmi设备的内容，并且在其中寻找它的中断基地址 rc = parse_spmi_dt_properties(chip, spmi); if (rc) { pr_err("Error registering spmi resource rc=%dn", rc); return rc; } //解析电池的参数，如v-cutoff-uv，关机电压，它不会读qcom的内容，会直接读qcom,后面的内容会有仔细说 rc = parse_bms_dt_properties(chip); if (rc) { pr_err("Unable to read all bms properties, rc = %dn", rc); return rc; } //查询错误的原因 if (chip->dt.cfg_disable_bms) { pr_info("VMBMS disabled (disable-bms = 1)n"); rc = qpnp_masked_write_base(chip, chip->base + EN_CTL_REG, BMS_EN_BIT, 0); if (rc) pr_err("Unable to disable VMBMS rc=%dn", rc); return -ENODEV; } //读取存在pm？PM里读出来的未经修正的原始数据？ rc = qpnp_read_wrapper(chip, chip->revision, chip->base + REVISION1_REG, 2); if (rc) { pr_err("Error reading version register rc=%dn", rc); return rc; } pr_debug("BMS version: %hhu.%hhun", chip->revision[1], chip->revision[0]); dev_set_drvdata(&spmi->dev, chip); device_init_wakeup(&spmi->dev, 1); mutex_init(&chip->bms_data_mutex); mutex_init(&chip->bms_device_mutex); mutex_init(&chip->last_soc_mutex); mutex_init(&chip->state_change_mutex); init_waitqueue_head(&chip->bms_wait_q); //初始化队列 /* read battery-id and select the battery profile */ //设置电池数据，也就是电池曲线 rc = set_battery_data(chip); if (rc) { pr_err("Unable to read battery data %dn", rc); goto fail_init; } /* set the battery profile */ //设置电池的配置文件，其实也就是配置刚刚设置好的全局变量了 rc = config_battery_data(chip->batt_data); if (rc) { pr_err("Unable to config battery data %dn", rc); goto fail_init; } //初始化wakeup_source，内核睡眠机制 wakeup_source_init(&chip->vbms_lv_wake_source.source, "vbms_lv_wake"); wakeup_source_init(&chip->vbms_cv_wake_source.source, "vbms_cv_wake"); wakeup_source_init(&chip->vbms_soc_wake_source.source, "vbms_soc_wake"); //初始化工作队列 INIT_DELAYED_WORK(&chip->monitor_soc_work, monitor_soc_work); INIT_DELAYED_WORK(&chip->voltage_soc_timeout_work, voltage_soc_timeout_work); //初始化配置状态，各种状态 bms_init_defaults(chip); //这一句看不懂了，可能是电池BMS算法用来读取硬件配置的 bms_load_hw_defaults(chip); //通过判断power_supply里面的函数来确定是否是正在充电的状态 is_bat_pres_ght =(is_battery_present(chip)); pr_err("is_bat_pres_ght =%dn",is_bat_pres_ght); ///if (is_battery_present(chip)) { //如果电池正在充电 if (is_bat_pres_ght) { //设置电池的设置低电(高电，高温，低温)的阈值，也就是电池低电关机 rc = setup_vbat_monitoring(chip); if (rc) { pr_err("fail to configure vbat monitoring rc=%dn", rc); goto fail_setup; } } //请求一些相应的中断BMS rc = bms_request_irqs(chip); if (rc) { pr_err("error requesting bms irqs, rc = %dn", rc); goto fail_irq; } //电池一些常规的检测，主要从PMIC上读到的相关信息 //电池的插入状态检测，判断手段是如果当前状态和之前状态不一样就判断电池拔出，并且确定电池是否存在，否则重置 battery_insertion_check(chip); //电池状态检测 battery_status_check(chip); /* character device to pass data to the userspace */ //向上层注册字符设备 rc = register_bms_char_device(chip); if (rc) { pr_err("Unable to regiter '/dev/vm_bms' rc=%dn", rc); goto fail_bms_device; } the_chip = chip; //这个也很重要，我们从上节知道，初值last_ocv_soc是非常重要的，决定着后面的soc估值算法，计算估值电压 calculate_initial_soc(chip); if (chip->dt.cfg_battery_aging_comp) { rc = calculate_initial_aging_comp(chip); if (rc) pr_err("Unable to calculate initial aging data rc=%dn", rc); } //设置和注册电池的power supply /* setup & register the battery power supply */ chip->bms_psy.name = "bms"; chip->bms_psy.type = POWER_SUPPLY_TYPE_BMS; chip->bms_psy.properties = bms_power_props; chip->bms_psy.num_properties = ARRAY_SIZE(bms_power_props); chip->bms_psy.get_property = qpnp_vm_bms_power_get_property; chip->bms_psy.set_property = qpnp_vm_bms_power_set_property; chip->bms_psy.external_power_changed = qpnp_vm_bms_ext_power_changed; chip->bms_psy.property_is_writeable = qpnp_vm_bms_property_is_writeable; chip->bms_psy.supplied_to = qpnp_vm_bms_supplicants; chip->bms_psy.num_supplicants = ARRAY_SIZE(qpnp_vm_bms_supplicants); //power_supply注册 rc = power_supply_register(chip->dev, &chip->bms_psy); if (rc < 0) { pr_err("power_supply_register bms failed rc = %dn", rc); goto fail_psy; } chip->bms_psy_registered = true; rc = get_battery_voltage(chip, &vbatt); if (rc) { pr_err("error reading vbat_sns adc channel=%d, rc=%dn", VBAT_SNS, rc); goto fail_get_vtg; } chip->debug_root = debugfs_create_dir("qpnp_vmbms", NULL); if (!chip->debug_root) pr_err("Couldn't create debug dirn"); if (chip->debug_root) { struct dentry *ent; ent = debugfs_create_file("bms_data", S_IFREG | S_IRUGO, chip->debug_root, chip, &bms_data_debugfs_ops); if (!ent) pr_err("Couldn't create bms_data debug filen"); ent = debugfs_create_file("bms_config", S_IFREG | S_IRUGO, chip->debug_root, chip, &bms_config_debugfs_ops); if (!ent) pr_err("Couldn't create bms_config debug filen"); ent = debugfs_create_file("bms_status", S_IFREG | S_IRUGO, chip->debug_root, chip, &bms_status_debugfs_ops); if (!ent) pr_err("Couldn't create bms_status debug filen"); } //这里启动工作队列，绝大部分的工作内容都是在这里完成的 schedule_delayed_work(&chip->monitor_soc_work, 0); /* * schedule a work to check if the userspace vmbms module * has registered. Fall-back to voltage-based-soc reporting * if it has not. */ // schedule_delayed_work(&chip->voltage_soc_timeout_work, msecs_to_jiffies(chip->dt.cfg_voltage_soc_timeout_ms)); pr_info("probe success: soc=%d vbatt=%d ocv=%d warm_reset=%dn", get_prop_bms_capacity(chip), vbatt, chip->last_ocv_uv, chip->warm_reset); return rc; fail_get_vtg: power_supply_unregister(&chip->bms_psy); fail_psy: device_destroy(chip->bms_class, chip->dev_no); cdev_del(&chip->bms_cdev); unregister_chrdev_region(chip->dev_no, 1); fail_bms_device: chip->bms_psy_registered = false; fail_irq: reset_vbat_monitoring(chip); fail_setup: wakeup_source_trash(&chip->vbms_lv_wake_source.source); wakeup_source_trash(&chip->vbms_cv_wake_source.source); wakeup_source_trash(&chip->vbms_soc_wake_source.source); fail_init: mutex_destroy(&chip->bms_data_mutex); mutex_destroy(&chip->last_soc_mutex); mutex_destroy(&chip->state_change_mutex); mutex_destroy(&chip->bms_device_mutex); the_chip = NULL; return rc; }
2.1 parse_bms_dt_properties()函数
在这里我们详细分析一下各个节点的内容，这里就挑几个比较重要的看看：（详细可以参考设备树里面的内容）
- v-cutoff-uv：如修改关机电压，除了修改这里，还需要修改电池曲线数据的qcom,v-cutoff-uv，其实最好是用电池曲线数据里的
- max-voltage-uv：电池最大的电压，单位为毫伏
- qcom,r-conn-mohm ：连接器的电阻
- s1-sample-interval-ms：状态s1下累加器的采样（毫秒）。（即）累加器充满vbat样本的速率。最小值=0最大值=2550ms。
- resume-soc：当充满的电池百分比低于此值，则重新开始充电。
- volatge-soc-timeout-ms：如果没有使用VMBMS算法来计算SOC，模块在此时间后基于SOC来报告电压。
- low-temp-threshold：当温度阈值低于此值，禁用IBAT求取平均值和UUC(不可用电量)平滑功能，如没指定默认为0，我们这里没有指定。
- qcom,ignore-shutdown-soc：有些不看翻译对大家都好；
- qcom,use-voltage-soc ：BMS根据此项的值来决定是否采用基于电压的SOC来替代基于库伦电量计的方式
- qcom,use-reported-soc ：此项使能reported_soc逻辑，而且要定义qcom,resume-soc为一个合适的值，BMS也需要控制充电、停止充电和重新充电。高通给出的代码默认是定义qcom,use-reported-soc，但我们核心板厂家注释掉此项，并增加qcom,report-charger-eoc
- qcom,report-charger-eoc： 指示BMS需要通知EOC(充电结束)给充电器
- qcom,disable-bms ：此属性用于关闭VM BMS硬件模块
2.2 set_battery_data()函数
这一部分内容就是设置电池曲线内容：
下面就是电池曲线的详细内容，不仔细说了：
static int set_battery_data(struct qpnp_bms_chip *chip) { int64_t battery_id; int rc = 0; struct bms_battery_data *batt_data; struct device_node *node; //里面的内容通过读取ADC来获取ID号 battery_id = read_battery_id(chip); if (battery_id < 0) { pr_err("cannot read battery id err = %lldn", battery_id); return battery_id; } node = of_find_node_by_name(chip->spmi->dev.of_node, "qcom,battery-data"); if (!node) { pr_err("No available batterydatan"); return -EINVAL; } batt_data = devm_kzalloc(chip->dev, sizeof(struct bms_battery_data), GFP_KERNEL); if (!batt_data) { pr_err("Could not alloc battery datan"); return -EINVAL; } batt_data->fcc_temp_lut = devm_kzalloc(chip->dev, sizeof(struct single_row_lut), GFP_KERNEL); batt_data->pc_temp_ocv_lut = devm_kzalloc(chip->dev, sizeof(struct pc_temp_ocv_lut), GFP_KERNEL); batt_data->rbatt_sf_lut = devm_kzalloc(chip->dev, sizeof(struct sf_lut), GFP_KERNEL); batt_data->ibat_acc_lut = devm_kzalloc(chip->dev, sizeof(struct ibat_temp_acc_lut), GFP_KERNEL); batt_data->max_voltage_uv = -1; batt_data->cutoff_uv = -1; batt_data->iterm_ua = -1; /* * if the alloced luts are 0s, of_batterydata_read_data ignores * them. */ rc = of_batterydata_read_data(node, batt_data, battery_id); if (rc || !batt_data->pc_temp_ocv_lut || !batt_data->fcc_temp_lut || !batt_data->rbatt_sf_lut || !batt_data->ibat_acc_lut) { pr_err("battery data load failedn"); devm_kfree(chip->dev, batt_data->fcc_temp_lut); devm_kfree(chip->dev, batt_data->pc_temp_ocv_lut); devm_kfree(chip->dev, batt_data->rbatt_sf_lut); devm_kfree(chip->dev, batt_data->ibat_acc_lut); devm_kfree(chip->dev, batt_data); return rc; } if (batt_data->pc_temp_ocv_lut == NULL) { pr_err("temp ocv lut table has not been loadedn"); devm_kfree(chip->dev, batt_data->fcc_temp_lut); devm_kfree(chip->dev, batt_data->pc_temp_ocv_lut); devm_kfree(chip->dev, batt_data->rbatt_sf_lut); devm_kfree(chip->dev, batt_data->ibat_acc_lut); devm_kfree(chip->dev, batt_data); return -EINVAL; } /* check if ibat_acc_lut is valid */ if (!batt_data->ibat_acc_lut->rows) { pr_info("ibat_acc_lut not presentn"); devm_kfree(chip->dev, batt_data->ibat_acc_lut); batt_data->ibat_acc_lut = NULL; } /* Override battery properties if specified in the battery profile */ if (batt_data->max_voltage_uv >= 0) chip->dt.cfg_max_voltage_uv = batt_data->max_voltage_uv; if (batt_data->cutoff_uv >= 0) chip->dt.cfg_v_cutoff_uv = batt_data->cutoff_uv; chip->batt_data = batt_data; return 0; }
在of_batterydata_read_data函数中有一个返回值：
of_batterydata_read_data-> of_batterydata_load_battery_data
of_batterydata_load_battery_data函数中有配置电池曲线的东西；
2.3 高通电量计
|
术语 |
全称 |
注释 |
|---|---|---|
|
FCC |
Full-Charge Capacity |
满电荷电量 |
|
UC |
Remaining capacity |
RC 剩余电量 |
|
CC |
Coulumb counter |
电量计 |
|
UUC |
Unusable capacity |
不可用电量 |
|
RUC |
Remaining usable capacity // |
RUC=RC-CC-UUC RUC=RC-CC-UUC，剩余可用电量 |
|
SoC |
State of charge |
电量百分比 |
|
OCV |
Open circuit voltage |
开路电压，电池在开路状态下的端电压称为开路电压 |
SOC=(RC-CC-UUC)/(FCC-UUC)
以下是各个变量的计算方法：
2.3.1 FCC：
在校准的电池profile中有定义,会随温度有变化；
static struct single_row_lut fcc_temp = { .x = {-20, 0, 25, 40, 60}, .y = {3193, 3190, 3190, 3180, 3183}, .cols = 5 }
对应电池曲线的qcom,fcc-temp-lut；
2.3.2 pc-temp-ocv-lut:
qcom,pc-temp-ocv-lut，为温度、SOC对应得电压表，PMU8909获取的电压值，通过查该表，在温度和电压下，可得到当前的SOC。
对应电池曲线的qcom,pc-temp-ocv-lut
2.3.3 rbatt-sf-lut:
rbatt-sf-lut，为温度、soc对应的电池内阻表，这里主要考虑内阻的影响，对OCV的修正，new_ocv=ocv+rbatt(内阻)*current（当前电流）。
对应电池曲线的qcom,rbatt-sf-lut
2.3.3 ibat-acc-luit
ibat-acc-luit，为温度、电流对应的acc表，这两个是起到修正SOC的作用
对应电池曲线的qcom, ibat-acc-luit
2.3.4 计算公式
soc_uuc = ((fcc - acc) * 100) / fcc，
//fcc在qcom,fcc-temp-lut查表可知、acc在qcom, ibat-acc-luit查表可知
soc_acc = DIV_ROUND_CLOSEST(100 * (soc_ocv - soc_uuc),(100 - soc_uuc));
//最终soc_acc，为上报的SOC.soc_ocv则是在qcom,pc-temp-ocv-lut查表可知
2.3.5 BMS算法
会上报事件uevent，当HAL层，收到消息，然后调用getprop的方法，获取相关的参数，如，电阻、电流、fcc、acc等，来估算出last_ocv_uv，然后调用setprop，把该值设下去，并启动工作线程，根据last_ocv_uv，查表得到soc，并经过修正SOC，并再次上报事件，循环下去。这个估值算法，我猜可能是一套学习算法，具体的没有源码，不清楚，只知道它把算法变为.bin文件，用了binder机制，作为服务一直运行。
我们如何知道monitor_soc_work函数不断的运行呢？
原因在于：
static void monitor_soc_work(struct work_struct *work) { ...... if ((chip->last_soc != chip->calculated_soc) || chip->dt.cfg_use_voltage_soc) schedule_delayed_work(&chip->monitor_soc_work, msecs_to_jiffies(get_calculation_delay_ms(chip))); }
2.3.6 分析如何确定初始的last_ocv_uv：
static int calculate_initial_soc(struct qpnp_bms_chip *chip) { ........ ........ //读当前电池温度 rc = get_batt_therm(chip, &batt_temp); ............ //读PON OCV rc = read_and_update_ocv(chip, batt_temp, true); .......... //读关机保存的soc和last_soc_uv rc = read_shutdown_ocv_soc(chip); //这里判断是使用估计soc还是估值soc。如果chip->warm_reset 为真 if (chip->warm_reset) { if (chip->shutdown_soc_invalid) { //这个是dtsi的一个配置选项，若没有配置， //则不使用关机soc est_ocv = estimate_ocv(chip); //估值soc chip->last_ocv_uv = est_ocv; } else { chip->last_ocv_uv = chip->shutdown_ocv;//使用关机的soc和ocv pr_err("Hyan %d : set chip->last_ocv_uv = %dn", __LINE__, chip->last_ocv_uv); chip->last_soc = chip->shutdown_soc; chip->calculated_soc = lookup_soc_ocv(chip, chip->shutdown_ocv, batt_temp); } } else { if (chip->workaround_flag & WRKARND_PON_OCV_COMP) adjust_pon_ocv(chip, batt_temp); /* !warm_reset use PON OCV only if shutdown SOC is invalid */ chip->calculated_soc = lookup_soc_ocv(chip, chip->last_ocv_uv, batt_temp); if (!chip->shutdown_soc_invalid && (abs(chip->shutdown_soc - chip->calculated_soc) < chip->dt.cfg_shutdown_soc_valid_limit)) { chip->last_ocv_uv = chip->shutdown_ocv; chip->last_soc = chip->shutdown_soc; chip->calculated_soc = lookup_soc_ocv(chip, chip->shutdown_ocv, batt_temp);//使用估值soc } else { chip->shutdown_soc_invalid = true; //使用关机soc } } ............. ............ } //得到PON OCV rc = read_and_update_ocv(chip, batt_temp, true); ocv_uv = convert_vbatt_raw_to_uv(chip, ocv_data, is_pon_ocv); uv = vadc_reading_to_uv(reading, true); //读ADC值 uv = adjust_vbatt_reading(chip, uv); //转化为soc_uv rc = qpnp_vbat_sns_comp_result(chip->vadc_dev, &uv, is_pon_ocv); //根据IC的类型，进行温度补偿 //从寄存器中读到储存的soc和ocv read_shutdown_ocv_soc rc = qpnp_read_wrapper(chip, (u8 *)&stored_ocv, chip->base + BMS_OCV_REG, 2); rc = qpnp_read_wrapper(chip, &stored_soc, chip->base + BMS_SOC_REG, 1); adjust_pon_ocv(struct qpnp_bms_chip *chip, int batt_temp) rc = qpnp_vadc_read(chip->vadc_dev, DIE_TEMP, &result); pc = interpolate_pc(chip->batt_data->pc_temp_ocv_lut, batt_temp, chip->last_ocv_uv / 1000); //根据ocv和temp，查表得PC(soc)。 rbatt_mohm = get_rbatt(chip, pc, batt_temp); //根据soc和temp，得电池内阻值 /* convert die_temp to DECIDEGC */ die_temp = (int)result.physical / 100; current_ma = interpolate_current_comp(die_temp); //当前电流 delta_uv = rbatt_mohm * current_ma; chip->last_ocv_uv += delta_uv; //修正last_ocv_uv //这个函数主要根据last_ocv_uv，计算出soc的 lookup_soc_ocv(struct qpnp_bms_chip *chip, int ocv_uv, int batt_temp) //查表得到soc_ocv，soc_cutoff soc_ocv = interpolate_pc(chip->batt_data->pc_temp_ocv_lut, batt_temp, ocv_uv / 1000); soc_cutoff = interpolate_pc(chip->batt_data->pc_temp_ocv_lut, batt_temp, chip->dt.cfg_v_cutoff_uv / 1000); soc_final = DIV_ROUND_CLOSEST(100 * (soc_ocv - soc_cutoff), (100 - soc_cutoff)); if (batt_temp > chip->dt.cfg_low_temp_threshold) iavg_ma = calculate_uuc_iavg(chip); else iavg_ma = chip->current_now / 1000; //查表得到FCC，ACC fcc = interpolate_fcc(chip->batt_data->fcc_temp_lut, batt_temp); acc = interpolate_acc(chip->batt_data->ibat_acc_lut, batt_temp, iavg_ma); //计算出UUC soc_uuc = ((fcc - acc) * 100) / fcc; if (batt_temp > chip->dt.cfg_low_temp_threshold) soc_uuc = adjust_uuc(chip, soc_uuc); //得到soc_acc soc_acc = DIV_ROUND_CLOSEST(100 * (soc_ocv - soc_uuc), (100 - soc_uuc)); soc_final = soc_acc; //这个为上报的soc chip->last_acc = acc;
在这里获取last_ocv_uv，温度；
2.3.7 工作队列monitor_soc_work
static void monitor_soc_work(struct work_struct *work) { struct qpnp_bms_chip *chip = container_of(work, struct qpnp_bms_chip, monitor_soc_work.work); int rc, new_soc = 0, batt_temp; bms_stay_awake(&chip->vbms_soc_wake_source); //计算上次工作队列和这次工作队列的差值 calculate_delta_time(&chip->tm_sec, &chip->delta_time_s); pr_debug("elapsed_time=%dn", chip->delta_time_s); mutex_lock(&chip->last_soc_mutex); //电池不存在，报100%电量 if (!is_battery_present(chip)) { /* if battery is not preset report 100% SOC */ pr_debug("battery gone, reporting 100n"); chip->last_soc_invalid = true; chip->last_soc = -EINVAL; new_soc = 100; } else { //检测电池电压 battery_voltage_check(chip); //假设这个qcom,use-voltage-soc节点打开，就使用电压来计算soc if (chip->dt.cfg_use_voltage_soc) { //通过电压计算soc calculate_soc_from_voltage(chip); } else { //获取电池的温度 rc = get_batt_therm(chip, &batt_temp); if (rc < 0) { pr_err("Unable to read batt temp rc=%d, using default=%dn", rc, BMS_DEFAULT_TEMP); batt_temp = BMS_DEFAULT_TEMP; } if (chip->last_soc_invalid) { chip->last_soc_invalid = false; chip->last_soc = -EINVAL; } //这里使用last_ocv_uv算出soc的 new_soc = lookup_soc_ocv(chip, chip->last_ocv_uv, batt_temp); /* clamp soc due to BMS hw/sw immaturities */ new_soc = clamp_soc_based_on_voltage(chip, new_soc); //上次的电压不等于这次的电压 if (chip->calculated_soc != new_soc) { pr_debug("SOC changed! new_soc=%d prev_soc=%dn", new_soc, chip->calculated_soc); chip->calculated_soc = new_soc; /* * To recalculate the catch-up time, clear it * when SOC changes. */ chip->catch_up_time_sec = 0; if (chip->calculated_soc == 100) /* update last_soc immediately */ report_vm_bms_soc(chip); pr_debug("update bms_psyn"); power_supply_changed(&chip->bms_psy); } else if (chip->last_soc != chip->calculated_soc) { pr_debug("update bms_psyn"); power_supply_changed(&chip->bms_psy); } else { report_vm_bms_soc(chip); } } /* low SOC configuration */ low_soc_check(chip); } /* * schedule the work only if last_soc has not caught up with * the calculated soc or if we are using voltage based soc */ if ((chip->last_soc != chip->calculated_soc) || chip->dt.cfg_use_voltage_soc) schedule_delayed_work(&chip->monitor_soc_work, msecs_to_jiffies(get_calculation_delay_ms(chip))); //复充标志位 if (chip->reported_soc_in_use && chip->charger_removed_since_full && !chip->charger_reinserted) { /* record the elapsed time after last reported_soc change */ chip->reported_soc_change_sec += chip->delta_time_s; pr_debug("reported_soc_change_sec=%dn", chip->reported_soc_change_sec); /* above the catch up time, calculate new reported_soc */ if (chip->reported_soc_change_sec > UI_SOC_CATCHUP_TIME) { calculate_reported_soc(chip); chip->reported_soc_change_sec = 0; } } mutex_unlock(&chip->last_soc_mutex); bms_relax(&chip->vbms_soc_wake_source); }
上面注释已经写的差不多了；看一下上报函数report_vm_bms_soc：
static int report_vm_bms_soc(struct qpnp_bms_chip *chip) { int soc, soc_change, batt_temp, rc; int time_since_last_change_sec = 0, charge_time_sec = 0; unsigned long last_change_sec; bool charging; soc = chip->calculated_soc; last_change_sec = chip->last_soc_change_sec; //计算上次电量改变的情况 calculate_delta_time(&last_change_sec, &time_since_last_change_sec); //判断电量是否正在充电 charging = is_battery_charging(chip); pr_debug("charging=%d last_soc=%d last_soc_unbound=%dn", charging, chip->last_soc, chip->last_soc_unbound); /* * account for charge time - limit it to SOC_CATCHUP_SEC to * avoid overflows when charging continues for extended periods */ //正在充电,last_soc是指上一次的最开始开机的soc，与计算出来的soc不一样，这是第一次，last_soc之后就会改变了，这里是初始化时间 if (charging && chip->last_soc != -EINVAL) { if (chip->charge_start_tm_sec == 0 || (chip->catch_up_time_sec == 0 && (abs(soc - chip->last_soc) >= MIN_SOC_UUC))) { /* * calculating soc for the first time * after start of chg. Initialize catchup time */ if (abs(soc - chip->last_soc) < MAX_CATCHUP_SOC) chip->catch_up_time_sec = (soc - chip->last_soc) * SOC_CATCHUP_SEC_PER_PERCENT; else chip->catch_up_time_sec = SOC_CATCHUP_SEC_MAX; chip->chg_start_soc = chip->last_soc; if (chip->catch_up_time_sec < 0) chip->catch_up_time_sec = 0; chip->charge_start_tm_sec = last_change_sec; pr_debug("chg_start_soc=%d charge_start_tm_sec=%d catch_up_time_sec=%dn", chip->chg_start_soc, chip->charge_start_tm_sec, chip->catch_up_time_sec); } charge_time_sec = min(SOC_CATCHUP_SEC_MAX, (int)last_change_sec - chip->charge_start_tm_sec); /* end catchup if calculated soc and last soc are same */ if (chip->last_soc == soc) { chip->catch_up_time_sec = 0; chip->chg_start_soc = chip->last_soc; } } //不充电状态 if (chip->last_soc != -EINVAL) { /* * last_soc < soc ... if we have not been charging at all * since the last time this was called, report previous SoC. * Otherwise, scale and catch up. */ rc = get_batt_therm(chip, &batt_temp); if (rc) batt_temp = BMS_DEFAULT_TEMP; if (chip->last_soc < soc && !charging) soc = chip->last_soc; else if (chip->last_soc < soc && soc != 100) soc = scale_soc_while_chg(chip, charge_time_sec, chip->catch_up_time_sec, soc, chip->chg_start_soc); /* * if the battery is close to cutoff or if the batt_temp * is under the low-temp threshold allow bigger change */ if (bms_wake_active(&chip->vbms_lv_wake_source) || (batt_temp <= chip->dt.cfg_low_temp_threshold)) soc_change = min((int)abs(chip->last_soc - soc), time_since_last_change_sec); else soc_change = min((int)abs(chip->last_soc - soc), time_since_last_change_sec / SOC_CHANGE_PER_SEC); if (chip->last_soc_unbound) { chip->last_soc_unbound = false; } else { /* * if soc have not been unbound by resume, * only change reported SoC by 1. */ soc_change = min(1, soc_change); } if (soc < chip->last_soc && soc != 0) soc = chip->last_soc - soc_change; if (soc > chip->last_soc && soc != 100) soc = chip->last_soc + soc_change; } if (chip->last_soc != soc && !chip->last_soc_unbound) chip->last_soc_change_sec = last_change_sec; /* * Check/update eoc under following condition: * if there is change in soc: * soc != chip->last_soc * during bootup if soc is 100: */ soc = bound_soc(soc); //当电池改变，或者在开机过程中达到100%的电量 if ((soc != chip->last_soc) || (soc == 100)) { chip->last_soc = soc; //在这个函数里面，如果report_soc==100的话，还是算是不充电的状态 //当上一次充电还是100，报告已经充满电了，假设有这个标志的话，qcom,use-reported-soc，会设置eoc_reported为true，这个在之后复充标志的时候有用到 check_eoc_condition(chip); //不充电状态并且设置的复充电量高于0%，这是必备条件 if ((chip->dt.cfg_soc_resume_limit > 0) && !charging) //里面的复充条件是 check_recharge_condition(chip); } pr_debug("last_soc=%d calculated_soc=%d soc=%d time_since_last_change=%dn", chip->last_soc, chip->calculated_soc, soc, time_since_last_change_sec); /* * Backup the actual ocv (last_ocv_uv) and not the * last_soc-interpolated ocv. This makes sure that * the BMS algorithm always uses the correct ocv and * can catch up on the last_soc (across reboots). * We do not want the algorithm to be based of a wrong * initial OCV. */ backup_ocv_soc(chip, chip->last_ocv_uv, chip->last_soc); //设备树中的qcom,use-reported-soc if (chip->reported_soc_in_use) //设置reported_soc为100 return prepare_reported_soc(chip); pr_debug("Reported SOC=%dn", chip->last_soc); return chip->last_soc; }
2.4 复充、充电、停止充电逻辑
通过阅读设备树知道resume-soc这个节点来控制：
在probe函数中通过宏定SPMI_PROP_READ_OPTIONAL义：
SPMI_PROP_READ_OPTIONAL(cfg_soc_resume_limit, "resume-soc", rc);
cfg_soc_resume_limit分别在以下这几个函数中使用过：
- check_recharge_condition函数，最后也是在report_vm_bms_soc函数中使用的
- report_vm_bms_soc函数：为内核线程中上报的函数，主要电池控制也在这个函数里面
- reported_soc_check_status函数
reported_soc_check_status -> qpnp_vm_bms_ext_power_changed //这个是个对调函数，暂时没看到哪里的有调到；
2.4.1 复充模式
check_recharge_condition函数：
static void check_recharge_condition(struct qpnp_bms_chip *chip) { int rc; union power_supply_propval ret = {0,}; int status = get_battery_status(chip); if (chip->last_soc > chip->dt.cfg_soc_resume_limit) return; if (status == POWER_SUPPLY_STATUS_UNKNOWN) { pr_debug("Unable to read battery statusn"); return; } /* Report recharge to charger for SOC based resume of charging */ if ((status != POWER_SUPPLY_STATUS_CHARGING) && chip->eoc_reported) { ret.intval = POWER_SUPPLY_STATUS_CHARGING; rc = chip->batt_psy->set_property(chip->batt_psy, POWER_SUPPLY_PROP_STATUS, &ret); if (rc < 0) { pr_err("Unable to set battery property rc=%dn", rc); } else { pr_info("soc dropped below resume_soc soc=%d resume_soc=%d, restart chargingn", chip->last_soc, chip->dt.cfg_soc_resume_limit); chip->eoc_reported = false; } } }
如果chip->last_soc高于设置的resume-soc复冲电压的话， 那么就return出来；
如果chip->last_soc低于设置的resume-soc复冲电压的话，就设置电源的充电状态，并设置set_property给上层；
我们可以看看这个函数在哪里使用的：
在函数的report_vm_bms_soc上使用的：
if ((soc != chip->last_soc) || (soc == 100)) { chip->last_soc = soc; check_eoc_condition(chip); if ((chip->dt.cfg_soc_resume_limit > 0) && !charging) check_recharge_condition(chip); }
当电压改变的时候，判断不在充电模式且设置的复充电容在95%；
2.4.2 停止充电模式
停止充电模式在函数的calculate_reported_soc函数中：
monitor_soc_work --> calculate_reported_soc
static void calculate_reported_soc(struct qpnp_bms_chip *chip) { union power_supply_propval ret = {0,}; if (chip->last_soc < 0) { pr_debug("last_soc is not ready, returnn"); return; } //这样就是处于充电模式 if (chip->reported_soc > chip->last_soc) { /*send DISCHARGING status if the reported_soc drops from 100 */ //当充电到100%的时候，设置停止充电的状态 if (chip->reported_soc == 100) { ret.intval = POWER_SUPPLY_STATUS_DISCHARGING; chip->batt_psy->set_property(chip->batt_psy, POWER_SUPPLY_PROP_STATUS, &ret); pr_debug("Report discharging status, reported_soc=%d, last_soc=%dn", chip->reported_soc, chip->last_soc); } /* * reported_soc_delta is used to prevent * the big change in last_soc, * this is not used in high current mode */ if (chip->reported_soc_delta > 0) chip->reported_soc_delta--; if (chip->reported_soc_high_current) chip->reported_soc--; else chip->reported_soc = chip->last_soc + chip->reported_soc_delta; pr_debug("New reported_soc=%d, last_soc is=%dn", chip->reported_soc, chip->last_soc); } else { chip->reported_soc_in_use = false; chip->reported_soc_high_current = false; pr_debug("reported_soc equals last_soc,stop reported_soc processn"); } pr_debug("bms power_supply_changedn"); power_supply_changed(&chip->bms_psy); }
现在我们想一想如何保持将100%的电压一直保持到95%到复充的状态呢？有一个非常重要的标志位charger_removed_since_full：
这个标志位是什么意思呢？字面意思就是当充电器被拔掉的时候是电量满电的；也就是说电量满电的之后（是之后），并且充电器没有拔掉的时候；看一下这个标志位是会在什么时候改变的吧：
static void reported_soc_check_status(struct qpnp_bms_chip *chip) { u8 present; present = is_charger_present(chip); pr_debug("usb_present=%dn", present); //当没有充电状态，并且false的状态 if (!present && !chip->charger_removed_since_full) { chip->charger_removed_since_full = true; pr_debug("reported_soc: charger removed since fulln"); return; } if (chip->reported_soc_high_current) { pr_debug("reported_soc in high current mode, returnn"); return; } if ((chip->reported_soc - chip->last_soc) > (100 - chip->dt.cfg_soc_resume_limit + HIGH_CURRENT_TH)) { chip->reported_soc_high_current = true; chip->charger_removed_since_full = true; chip->charger_reinserted = false; pr_debug("reported_soc enters high current moden"); return; } if (present && chip->charger_removed_since_full) { chip->charger_reinserted = true; pr_debug("reported_soc: charger reinsertedn"); } if (!present && chip->charger_removed_since_full) { chip->charger_reinserted = false; pr_debug("reported_soc: charger removed againn"); } }
但这个函数也要在一定条件下才能进来，同样也需要reported_soc_in_use标志位来使用：
if (chip->reported_soc_in_use) reported_soc_check_status(chip);
最开始的时候reported_soc_in_use已经是true的状态了，只有两种情况会改变它，
- 在重新插入的情况下，充完了电；
- 在
calculate_reported_soc函数中，属于放电的状态；
3. 流程图
