MTK充电温度保护机制

问题点

发现低温箱关机状态下能充进去电。开机是正常的。

参考

kernel充电温度保护机制

drivers/power/supply/mediatek/charger/mtk_charger.c
充电保护线程：

dts：
/* Battery Temperature Protection */
#define MIN_CHARGE_TEMP  0
#define MIN_CHARGE_TEMP_PLUS_X_DEGREE	6
#define MAX_CHARGE_TEMP  50
#define MAX_CHARGE_TEMP_MINUS_X_DEGREE	47

static void charger_check_status(struct charger_manager *info)
{
	bool charging = true;
	int temperature;
	struct battery_thermal_protection_data *thermal;

	if (mt_get_charger_type() == CHARGER_UNKNOWN)
		return;

	temperature = info->battery_temp;
	thermal = &info->thermal;

	if (info->enable_sw_jeita == true) {
		do_sw_jeita_state_machine(info);
		if (info->sw_jeita.charging == false) {
			charging = false;
			goto stop_charging;
		}
	} else {

		if (thermal->enable_min_charge_temp) { //温度过低，低于0度
			if (temperature < thermal->min_charge_temp) {
				chr_err("Battery Under Temperature or NTC fail %d %d\n",
					temperature, thermal->min_charge_temp);
				thermal->sm = BAT_TEMP_LOW;
				charging = false;
				goto stop_charging; //小于0°，停止充电
			} else if (thermal->sm == BAT_TEMP_LOW) {//温度小于0度后，升上来了
				if (temperature >=
				    thermal->min_charge_temp_plus_x_degree) {//温度大于6度了
					chr_err("Battery Temperature raise from %d to %d(%d), allow charging!!\n",
					thermal->min_charge_temp,
					temperature,
					thermal->min_charge_temp_plus_x_degree);
					thermal->sm = BAT_TEMP_NORMAL;
				} else {
					charging = false;
					goto stop_charging;
				}
			}
		}

		if (temperature >= thermal->max_charge_temp) { //温度太高，高于50度
			chr_err("Battery over Temperature or NTC fail %d %d\n",
				temperature, thermal->max_charge_temp);
			thermal->sm = BAT_TEMP_HIGH;
			charging = false;
			goto stop_charging;
		} else if (thermal->sm == BAT_TEMP_HIGH) {//温度大于50度后，降下来了
			if (temperature
			    < thermal->max_charge_temp_minus_x_degree) { //现在温度小于47度了
				chr_err("Battery Temperature raise from %d to %d(%d), allow charging!!\n",
				thermal->max_charge_temp,
				temperature,
				thermal->max_charge_temp_minus_x_degree);
				thermal->sm = BAT_TEMP_NORMAL;
			} else {
				charging = false;
				goto stop_charging;
			}
		}
	}

	mtk_chg_get_tchg(info);

	if (!mtk_chg_check_vbus(info)) {
		charging = false;
		goto stop_charging;
	}

	if (info->cmd_discharging)
		charging = false;
	if (info->safety_timeout)
		charging = false;
	if (info->vbusov_stat)
		charging = false;

stop_charging:
	mtk_battery_notify_check(info);

	chr_err("tmp:%d (jeita:%d sm:%d cv:%d en:%d) (sm:%d) en:%d c:%d s:%d ov:%d %d %d\n",
		temperature, info->enable_sw_jeita, info->sw_jeita.sm,
		info->sw_jeita.cv, info->sw_jeita.charging, thermal->sm,
		charging, info->cmd_discharging, info->safety_timeout,
		info->vbusov_stat, info->can_charging, charging);

	if (charging != info->can_charging)
		_charger_manager_enable_charging(info->chg1_consumer,
						0, charging);

	info->can_charging = charging;
}

过压保护和温度保护通知，往底层节点
BatteryNotify
写异常标志,同时framework监听该节点并往上层app发送广播事件来显示充电危险。若是关机充电，重启后
kpoc_charger
程序将读取这个节点的异常值，显示危险断开充电图标。：

在这里插入图片描述

不正常状态如下:
/* charging abnormal status */
#define CHG_VBUS_OV_STATUS	(1 << 0)
#define CHG_BAT_OT_STATUS	(1 << 1)
#define CHG_OC_STATUS		(1 << 2)
#define CHG_BAT_OV_STATUS	(1 << 3)
#define CHG_ST_TMO_STATUS	(1 << 4)
#define CHG_BAT_LT_STATUS	(1 << 5)
#define CHG_TYPEC_WD_STATUS	(1 << 6)


static void mtk_battery_notify_check(struct charger_manager *info)
{
	if (info->notify_test_mode == 0x0000) {
		mtk_battery_notify_VCharger_check(info);
		mtk_battery_notify_VBatTemp_check(info);
	} else {
		mtk_battery_notify_UI_test(info);
	}
}


static void mtk_battery_notify_VCharger_check(struct charger_manager *info)
{
#if defined(BATTERY_NOTIFY_CASE_0001_VCHARGER)
	int vchr = 0;

	vchr = battery_get_vbus() * 1000; /* uV */
	if (vchr < info->data.max_charger_voltage)
		info->notify_code &= ~CHG_VBUS_OV_STATUS;
	else {
		info->notify_code |= CHG_VBUS_OV_STATUS;
		chr_err("[BATTERY] charger_vol(%d mV) > %d mV\n",
			vchr / 1000, info->data.max_charger_voltage / 1000);
		mtk_chgstat_notify(info);
	}
#endif
}
温度过高过低保护：
static void mtk_battery_notify_VBatTemp_check(struct charger_manager *info)
{
#if defined(BATTERY_NOTIFY_CASE_0002_VBATTEMP)
	if (info->battery_temp >= info->thermal.max_charge_temp) {
		info->notify_code |= CHG_BAT_OT_STATUS;
		chr_err("[BATTERY] bat_temp(%d) out of range(too high)\n",
			info->battery_temp);
		mtk_chgstat_notify(info);
	} else {
		info->notify_code &= ~CHG_BAT_OT_STATUS;  //高温标志
	}

	if (info->enable_sw_jeita == true) {
		if (info->battery_temp < info->data.temp_neg_10_thres) {
			info->notify_code |= CHG_BAT_LT_STATUS;
			chr_err("bat_temp(%d) out of range(too low)\n",
				info->battery_temp);
			mtk_chgstat_notify(info);
		} else {
			info->notify_code &= ~CHG_BAT_LT_STATUS;
		}
	} else {
#ifdef BAT_LOW_TEMP_PROTECT_ENABLE //这个宏默认没打开，需要打开
		if (info->battery_temp < info->thermal.min_charge_temp) {
			info->notify_code |= CHG_BAT_LT_STATUS;
			chr_err("bat_temp(%d) out of range(too low)\n",
				info->battery_temp);
			mtk_chgstat_notify(info);
		} else {
			info->notify_code &= ~CHG_BAT_LT_STATUS;
		}
#endif
	}
#endif
}

下面这个就是通过uevent往上层发送异常事件，貌似不知道是在干嘛：
static int mtk_chgstat_notify(struct charger_manager *info)
{
	int ret = 0;
	char *env[2] = { "CHGSTAT=1", NULL };

	chr_err("%s: 0x%x\n", __func__, info->notify_code);
	ret = kobject_uevent_env(&info->pdev->dev.kobj, KOBJ_CHANGE, env);
	if (ret)
		chr_err("%s: kobject_uevent_fail, ret=%d", __func__, ret);

	return ret;
}

改变
info->notify_code
值其实就是改变sys节点
/sys/devices/platform/charger/BatteryNotify
的值：

static ssize_t show_BatNotify(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct charger_manager *pinfo = dev->driver_data;

	pr_debug("[Battery] show_BatteryNotify: 0x%x\n", pinfo->notify_code);

	return sprintf(buf, "%u\n", pinfo->notify_code);
}

static ssize_t store_BatNotify(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t size)
{
	struct charger_manager *pinfo = dev->driver_data;
	unsigned int reg = 0;
	int ret;

	pr_debug("[Battery] store_BatteryNotify\n");
	if (buf != NULL && size != 0) {
		pr_debug("[Battery] buf is %s and size is %zu\n", buf, size);
		ret = kstrtouint(buf, 16, &reg);
		pinfo->notify_code = reg;
		pr_debug("[Battery] store code: 0x%x\n", pinfo->notify_code);
		mtk_chgstat_notify(pinfo);
	}
	return size;
}

static DEVICE_ATTR(BatteryNotify, 0664, show_BatNotify, store_BatNotify);

frameworks层发送广播

vendor/mediatek/proprietary/frameworks/opt/batterywarning/batterywarning.cpp
:

uevent事件轮询：
* batterywarn_init
    * uevent_init()
        * batterywarn_register_event(uevent_fd, uevent_event) //注册uevent_event

如下，如果 type>0，就发送广播sendBroadcastMessage(String16(ACTION), type);
上层会接受这个广播，根据type去提醒系统。

#define UEVENT_MSG_LEN 2048
static void uevent_event(uint32_t /*epevents*/) {
    char msg[UEVENT_MSG_LEN + 2];
    char *cp;
    char *status;
    int n;
    char *buffer = (char*) malloc(MAX_CHAR * sizeof(char));
    if (buffer == NULL) {
        ALOGD("malloc memory failed");
        return ;
    }
    n = uevent_kernel_multicast_recv(uevent_fd, msg, UEVENT_MSG_LEN);
    if (n <= 0) return;
    if (n >= UEVENT_MSG_LEN) /* overflow -- discard */
        return;

    msg[n] = '\0';
    msg[n + 1] = '\0';
    cp = msg;

    while (*cp) {

        if (!strncmp(cp, "CHGSTAT=", strlen("CHGSTAT="))) { // This CHGSTAT value will be provided by kernel driver
            readType(buffer);
            break;
        }

        /* advance to after the next \0 */
        while (*cp++)
            ;
    }
    free(buffer);
}

void readType(char* buffer) {
    FILE * pFile;
    int file_index;
    file_index=get_charger_file_path();
    ALOGD("Inside file_index value : %d\n", file_index);
    pFile = fopen(charger_file_path[file_index], "r");
    if (pFile == NULL) {
        ALOGE("error opening file");
        return;
    } else {
        if (fgets(buffer, MAX_CHAR, pFile) == NULL) {
            fclose(pFile);
            ALOGE("can not get the string from the file");
            return;
        }
    }
    fclose(pFile);
    int type = atoi(buffer);
    if (type==0)
    {
        ALOGD("start activity by send intent to BatteryWarningReceiver to remove notification, type = %d\n", type);
        sendBroadcastMessage(String16(NORMAL_ACTION), type);
    }
    if (type > 0) //如果 type>0，就发送广播
    {
        ALOGD("start activity by send intent to BatteryWarningReceiver, type = %d\n", type);
        sendBroadcastMessage(String16(ACTION), type);
    }
}




static int batterywarn_init() {
    epollfd = epoll_create(MAX_EPOLL_EVENTS);
    if (epollfd == -1) {
        ALOGD("epoll_create failed; errno=%d\n", errno);
        return -1;
    }
    uevent_init();
    return 0;

}


int main()
{
    char *buffer = (char*) malloc(MAX_CHAR * sizeof(char));
    if (buffer == NULL) {
        ALOGD("malloc memory failed");
        return 0;
    }
  int ret;

  /* Read the status to catch the event when batterywarning is not started */
  readType(buffer);

  ret= batterywarn_init();
  if (ret) {
      ALOGD("Initialization failed, exiting\n");
      exit(1);
  }
  batterywarn_mainloop();
  free(buffer);
  return 0;

app接收广播

有人发送广播，就有人接收广播，因此继续跟踪谁接收了这个广播。

vendor/mediatek/proprietary/packages/apps/BatteryWarning/src/com/mediatek/batterywarning/BatteryWarningReceiver.java
:

在这里插入图片描述

分析这里面时，获取发送的广播，然后启动activity（BatteryWarningActivity），并且把type的值放在inten中传递过去。

type含义类型

    private static final int CHARGER_OVER_VOLTAGE_TYPE = 0;
    private static final int BATTERY_OVER_TEMPERATURE_TYPE = 1;
    private static final int CURRENT_OVER_PROTECTION_TYPE = 2;
    private static final int BATTERY_OVER_VOLTAGE_TYPE = 3;
    private static final int SAFETY_OVER_TIMEOUT_TYPE = 4;
    private static final int BATTERY_LOW_TEMPERATURE_TYPE = 5;
    private static final int TYPEC_DETECTION_WATER_GAS_TYPE = 6;

CHARGER_OVER_VOLTAGE_TYPE = 0;//充电电压过高
BATTERY_OVER_TEMPERATURE_TYPE = 1;//电池温度过高
CURRENT_OVER_PROTECTION_TYPE = 2;//超过电流保护
BATTERY_OVER_VOLTAGE_TYPE = 3;//电池电压过高
SAFETY_OVER_TIMEOUT_TYPE = 4;//充电时间过长
BATTERY_LOW_TEMPERATURE_TYPE = 5;//电池温度过低

在onCreate()方法中，如果mType类型在0-5之间，就调用showWarningDialog()弹出提醒框。

分析到这里，整体的流程已经弄明白了，那么客制化的实现也很简单了。

原文链接：https://blog.csdn.net/u011784994/article/details/111656537

问题点

参考

kernel充电温度保护机制

frameworks层发送广播

app接收广播

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