android电池充电以及电量检测驱动分析
前段时间比较烦躁，各种不想学习不想工作，于是休息了几天。这几天又下来任务了--调试充电电路和电池电量检测电路，于是又开始工作，顺便把调试过程记录下来。
平台： cpu 飞思卡尔imx6q 4核
充电芯片 MAX8903
电量检测芯片 MAX11801
android版本 android4.0
一、电量检测
我们用的电池电量检测芯片MAX11801其实是一款电阻触摸屏的驱动芯片，它外带一个AD采集引脚，因此我们用这个引脚来检测电池电压。MAX11801电源为3.3V而电池电压范围可能是0~4.2V，因此我们需要给电池电压分压。我们所用的电路如下
知道了硬件电路下面来 添加这个芯片的驱动，这是一个i2c的芯片，因此首先在board文件中添加i2c设备
I2C_BOARD_INFO("max11801", 0x48),
.platform_data = (void *)&max11801_mode,
.irq = gpio_to_irq(SABRESD_TS_INT),
}, 然后添加这个芯片的驱动文件放在/drivers/input/touchiscreen/max11801_ts.c
对于这个驱动文件我们只要读取出AD的值就可以了，对于触摸屏部分我们并不需要，因此主要是下面几个函数
static u32 max11801_dcm_sample_aux(struct i2c_client *client)
{
u8 temp_buf;
int ret;
int aux = 0;
u32 sample_data = 0;
/* AUX_measurement*/
max11801_dcm_write_command(client, AUX_measurement);//发送AD采集命令
mdelay(5);
ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_AUX_MSB, //读取高字节数据
1, &temp_buf);
if (ret < 1)
printk(KERN_DEBUG "FIFO_RD_AUX_MSB read fails\n");
else
aux_buf[0] = temp_buf;
mdelay(5);
ret = i2c_smbus_read_i2c_block_data(client, FIFO_RD_AUX_LSB, //读取低字节数据
1, &temp_buf);
if (ret < 1)
printk(KERN_DEBUG "FIFO_RD_AUX_LSB read fails\n");
else
aux_buf[1] = temp_buf;
aux = (aux_buf[0] << 4) + //视最低4位无效并去掉
(aux_buf[1] >> 4);
/*
10k和18.7k并联后电阻
R=18.7*10/(18.7+10)=6.516
V(aux) = V(bat)*6.516/(6.516+18.7)
V(aux) = aux*3300/0xfff
V(bat) = aux*1386880/444717
*/
sample_data = (aux*1386880)/444717; //计算出电池电压
return sample_data;
}
u32 max11801_read_adc(void)
{
u32 adc_data;
adc_data = max11801_dcm_sample_aux(max11801_client);
// printk("----%s %d\n",__func__,adc_data); //lijianzhang
return adc_data;
}
EXPORT_SYMBOL_GPL(max11801_read_adc);
由于电池电量检测的驱动非常简单，而且和充电驱动关系非常密切，因此一般都卸载充电驱动里面，我们也是这么做的。下面的代码都是从充电驱动中摘出来的，因此当大家看到，一些设备文件和函数参数类型 都是充电驱动中的 时候不要太奇怪。
通过上面的max11801_read_adc函数我们已经得到了理论计算的电池的电压，但实际应用中由于分压电阻误差，焊接问题等，这个电压会有一定的误差因此需要一个校正函数
u32 calibration_voltage(struct max8903_data *data)
{
int volt[ADC_SAMPLE_COUNT];
u32 voltage_data;
int i;
for (i = 0; i < ADC_SAMPLE_COUNT; i++) { //多次采样，防止AD误差
if (data->charger_online == 0 && data->usb_charger_online == 0) {
/* ADC offset when battery is discharger*/
volt[i] = max11801_read_adc()-offset_discharger; //没有充电情况下 电压误差
} else {
if (data->charger_online == 1)
volt[i] = max11801_read_adc()-offset_charger;//DC充电式 电压误差
else if (data->usb_charger_online == 1)
volt[i] = max11801_read_adc()-offset_usb_charger;//usb充电 电压误差
else if (data->charger_online == 1 && data->usb_charger_online == 1)
volt[i] = max11801_read_adc()-offset_charger;
}
}
sort(volt, i, 4, cmp_func, NULL);//对电压排序
for (i = 0; i < ADC_SAMPLE_COUNT; i++)
pr_debug("volt_sorted[%2d]: %d\n", i, volt[i]);
/* get the average of second max/min of remained. */
voltage_data = (volt[2] + volt[ADC_SAMPLE_COUNT - 3]) / 2;//去掉最大值最小值 并对剩余数据求平均
return voltage_data;
}从上面函数我们读取到了正确的电压值。电池电压是随时变化的，我们要检测电池电量，必须随时采集，因此用一个定时器来做这件事情，代码如下：
INIT_DELAYED_WORK(&data->work, max8903_battery_work); schedule_delayed_work(&data->work, data->interval);
电压采集完成后就是将电压上报出去，上报的过程是：我们读取到电压变化->告诉android端电池电压变化了->android会通过power_supply设备文件来读取具体的电压值。
我们来看定时器回调函数
static void max8903_battery_work(struct work_struct *work)
{
struct max8903_data *data;
data = container_of(work, struct max8903_data, work.work);
data->interval = HZ * BATTERY_UPDATE_INTERVAL;
max8903_charger_update_status(data); //检测充电状态
max8903_battery_update_status(data); //检测电池状态
/* reschedule for the next time */
schedule_delayed_work(&data->work, data->interval);//定时器继续
}检测电池状态函数
static void max8903_battery_update_status(struct max8903_data *data)
{
int temp;
static int temp_last;
bool changed_flag;
changed_flag = false;
mutex_lock(&data->work_lock);
temp = calibration_voltage(data);
if (temp_last == 0) {
data->voltage_uV = temp;
temp_last = temp;
}
if (data->charger_online == 0 && temp_last != 0) {//DC充电状态
if (temp < temp_last) {
temp_last = temp;
data->voltage_uV = temp;
} else {
data->voltage_uV = temp_last;
}
}
if (data->charger_online == 1 || data->usb_charger_online == 1) {//USB充电状态和DC充电状态
data->voltage_uV = temp;
temp_last = temp;
}
data->percent = calibrate_battery_capability_percent(data);//计算电量的百分比
if (data->percent != data->old_percent) { //电池电压有变化
data->old_percent = data->percent;
changed_flag = true;
}
if (changed_flag) { //如果有变化
changed_flag = false;
power_supply_changed(&data->bat);//告诉android端 电池电量改变了
}
/*
because boot time gap between led framwork and charger
framwork,when system boots with charger attatched, charger
led framwork loses the first charger online event,add once extra
power_supply_changed can fix this issure
*/
if (data->first_delay_count < 200) {
data->first_delay_count = data->first_delay_count + 1 ;
power_supply_changed(&data->bat);
}
mutex_unlock(&data->work_lock);
}
这里我们看到了
power_supply_changed(&data->bat);告诉android端 电池电量改变了，那么下一步android来读取具体电压，就涉及到了power_supply设备文件。
来看设备文件的建立过程
data->bat.name = "max8903-charger";
data->bat.type = POWER_SUPPLY_TYPE_BATTERY;
data->bat.properties = max8903_battery_props;
data->bat.num_properties = ARRAY_SIZE(max8903_battery_props);
data->bat.get_property = max8903_battery_get_property;
data->bat.use_for_apm = 1;
retval = power_supply_register(&pdev->dev, &data->bat);//注册设备文件
if (retval) {
dev_err(data->dev, "failed to register battery\n");
goto battery_failed;
}这里注册了一个名为max8903-charger的
power_supply设备文件，这个设备文件包含了ARRAY_SIZE(max8903_battery_props)个操作分别为
static enum power_supply_property max8903_battery_props[] = {
POWER_SUPPLY_PROP_VOLTAGE_NOW,//当前电压
POWER_SUPPLY_PROP_STATUS, //当前充电状态
POWER_SUPPLY_PROP_PRESENT, //不太清除
POWER_SUPPLY_PROP_CAPACITY, //电量百分比
POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN,//电池极限电压 最大值
POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,//电池极限电压 最小值
POWER_SUPPLY_PROP_HEALTH, //电池健康状态
POWER_SUPPLY_PROP_CAPACITY_LEVEL,//电量水平，low或者normal
};这些状态是通过max8903_battery_get_property()这个函数来读取的
static int max8903_battery_get_property(struct power_supply *bat,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max8903_data *di = container_of(bat,
struct max8903_data, bat);
switch (psp) {
case POWER_SUPPLY_PROP_STATUS:
val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
if (gpio_get_value(di->pdata->chg) == 0) {
di->battery_status = POWER_SUPPLY_STATUS_CHARGING; //正在充电
} else if (di->ta_in &&
gpio_get_value(di->pdata->chg) == 1) {
if (di->percent >= 99)
di->battery_status = POWER_SUPPLY_STATUS_FULL;//电量大于99就充满了
else
di->battery_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
}
else if (di->usb_in &&
gpio_get_value(di->pdata->chg) == 1) {
if (di->percent >= 99)
di->battery_status = POWER_SUPPLY_STATUS_FULL;
else
di->battery_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
}
val->intval = di->battery_status;
return 0;
default:
break;
}
switch (psp) {
case POWER_SUPPLY_PROP_VOLTAGE_NOW:
val->intval = di->voltage_uV;
break;
case POWER_SUPPLY_PROP_CHARGE_NOW:
val->intval = 0;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MAX_DESIGN:
val->intval = HIGH_VOLT_THRESHOLD;
break;
case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
val->intval = LOW_VOLT_THRESHOLD;
break;
case POWER_SUPPLY_PROP_PRESENT:
val->intval = 1;
break;
case POWER_SUPPLY_PROP_CAPACITY:
val->intval = di->percent < 0 ? 0 :
(di->percent > 100 ? 100 : di->percent);
break;
case POWER_SUPPLY_PROP_HEALTH:
val->intval = POWER_SUPPLY_HEALTH_GOOD;
if (di->fault)
val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
break;
case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
if (di->battery_status == POWER_SUPPLY_STATUS_FULL)
val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
else if (di->percent <= 15)
val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW; //电量小于15%就报低电量
else
val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;//否则就报正常
break;
default:
return -EINVAL;
}
return 0;
}
当我们注册设备文件以后，可以在/sys/devices/platform/max8903-charger.1/power_supply/max8903-charger目录下找到其设备文件如下
我们通过cat命令就可以随时查看电池状态。
二、电池电压校正参数
上面我们知道根据硬件实际情况不同，AD采集出来的电池电压需要校正参数。也就是
static int offset_discharger;
static int offset_charger;
static int offset_usb_charger;
对于这三个参数，当然我们可以在驱动力写死，但是为了以后的兼容性我们可以通过android上层来设置，当我们设备出厂时候，通过一配置文件方便的来修改这三个参数，下面我们就来介绍一下，怎么用设备文件和脚本，来修改者三个参数：
我们用的是sys文件系统的设备文件，创建代码为
ret = device_create_file(&pdev->dev, &max8903_discharger_dev_attr); if (ret) dev_err(&pdev->dev, "create device file failed!\n"); ret = device_create_file(&pdev->dev, &max8903_charger_dev_attr); if (ret) dev_err(&pdev->dev, "create device file failed!\n"); ret = device_create_file(&pdev->dev, &max8903_usb_charger_dev_attr); if (ret) dev_err(&pdev->dev, "create device file failed!\n");设备文件的实现代码为
static ssize_t max8903_voltage_offset_discharger_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "read offset_discharger:%04d\n",
offset_discharger);
}
static ssize_t max8903_voltage_offset_discharger_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
offset_discharger = simple_strtoul(buf, NULL, 10);
pr_info("read offset_discharger:%04d\n", offset_discharger);
return count;
}
static ssize_t max8903_voltage_offset_charger_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "read offset_charger:%04d\n",
offset_charger);
}
static ssize_t max8903_voltage_offset_charger_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
offset_charger = simple_strtoul(buf, NULL, 10);
pr_info("read offset_charger:%04d\n", offset_charger);
return count;
}
static ssize_t max8903_voltage_offset_usb_charger_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
return sprintf(buf, "read offset_usb_charger:%04d\n",
offset_usb_charger);
}
static ssize_t max8903_voltage_offset_usb_charger_store(struct device *dev,
struct device_attribute *attr, const char *buf,
size_t count)
{
offset_usb_charger = simple_strtoul(buf, NULL, 10);
pr_info("read offset_charger:%04d\n", offset_usb_charger);
return count;
}
static struct device_attribute max8903_discharger_dev_attr = {
.attr = {
.name = "max8903_ctl_offset_discharger",
.mode = S_IRUSR | S_IWUSR,
},
.show = max8903_voltage_offset_discharger_show,
.store = max8903_voltage_offset_discharger_store,
};
static struct device_attribute max8903_charger_dev_attr = {
.attr = {
.name = "max8903_ctl_offset_charger",
.mode = S_IRUSR | S_IWUSR,
},
.show = max8903_voltage_offset_charger_show,
.store = max8903_voltage_offset_charger_store,
};
static struct device_attribute max8903_usb_charger_dev_attr = {
.attr = {
.name = "max8903_ctl_offset_usb_charger",
.mode = S_IRUSR | S_IWUSR,
},
.show = max8903_voltage_offset_usb_charger_show,
.store = max8903_voltage_offset_usb_charger_store,
};
这样，我们就可以在/sys/devices/platform/max8903-charger.1目录下看到这样三个设备文件
我们用cat命令可以读出当前值，用echo "500">>max8903_ctl_offset_charger 可以修改当前值
这样我们就可以在系统启动的时候，用脚本来自动修改者三个值，我用的办法是在init.rc的on boot阶段增加这么三行
#battery charge
write /sys/devices/platform/max8903-charger.1/max8903_ctl_offset_charger 150
write /sys/devices/platform/max8903-charger.1/max8903_ctl_offset_discharger 200
write /sys/devices/platform/max8903-charger.1/max8903_ctl_offset_usb_charger 250当然大家也可以把这三行命令写在另外一个脚本里，然后init.rc中调用
三、电池充电
电池充电的电路
一共有4个引脚输出到cpu中：
CHG_FLT1_B 电池检测错误
UOK_B usb插入
DOK_B DC插入
CHG_STATUS1_B 充电状态
对于充电状态的检测过程，和电量检测基本相同， 检测到状态变化->告诉android层发生变化->android层通过设备文件来读取变化值
知道了这些我们来看驱动，首先在board文件中添加max8903设备
static struct max8903_pdata charger1_data = {
.dok = SABRESD_CHARGE_DOK_B,
.uok = SABRESD_CHARGE_UOK_B,
.chg = CHARGE_STATE2,
.flt = CHARGE_STATE1,
.dcm_always_high = true,
.dc_valid = true,
.usb_valid = true,
};
static struct platform_device sabresd_max8903_charger_1 = {
.name = "max8903-charger",
.id = 1,
.dev = {
.platform_data = &charger1_data,
},
};
platform_device_register(&sabresd_max8903_charger_1);然后在/derivers/power/目录下添加驱动文件。充电状态的变化都是IO电平的变化，我们来看驱动是怎么处理这4个io的，首先在probe函数中
申请IO
if (pdata->dc_valid) {
if (pdata->dok && gpio_is_valid(pdata->dok)) {
gpio = pdata->dok; /* PULL_UPed Interrupt */
/* set DOK gpio input */
ret = gpio_request(gpio, "max8903-DOK");
if (ret) {
printk(KERN_ERR"request max8903-DOK error!!\n");
goto err;
} else {
gpio_direction_input(gpio);
}
ta_in = gpio_get_value(gpio) ? 0 : 1;
} else if (pdata->dok && gpio_is_valid(pdata->dok) && pdata->dcm_always_high) {
ta_in = pdata->dok; /* PULL_UPed Interrupt */
ta_in = gpio_get_value(gpio) ? 0 : 1;
} else {
dev_err(dev, "When DC is wired, DOK and DCM should"
" be wired as well."
" or set dcm always high\n");
ret = -EINVAL;
goto err;
}
}
if (pdata->usb_valid) {
if (pdata->uok && gpio_is_valid(pdata->uok)) {
gpio = pdata->uok;
/* set UOK gpio input */
ret = gpio_request(gpio, "max8903-UOK");
if (ret) {
printk(KERN_ERR"request max8903-UOK error!!\n");
goto err;
} else {
gpio_direction_input(gpio);
}
usb_in = gpio_get_value(gpio) ? 0 : 1;
} else {
dev_err(dev, "When USB is wired, UOK should be wired."
"as well.\n");
ret = -EINVAL;
goto err;
}
}
if (pdata->chg) {
if (!gpio_is_valid(pdata->chg)) {
dev_err(dev, "Invalid pin: chg.\n");
ret = -EINVAL;
goto err;
}
/* set CHG gpio input */
ret = gpio_request(pdata->chg, "max8903-CHG");
if (ret) {
printk(KERN_ERR"request max8903-CHG error!!\n");
goto err;
} else {
gpio_direction_input(pdata->chg);
}
}
if (pdata->flt) {
if (!gpio_is_valid(pdata->flt)) {
dev_err(dev, "Invalid pin: flt.\n");
ret = -EINVAL;
goto err;
}
/* set FLT gpio input */
ret = gpio_request(pdata->flt, "max8903-FLT");
if (ret) {
printk(KERN_ERR"request max8903-FLT error!!\n");
goto err;
} else {
gpio_direction_input(pdata->flt);
}
}
if (pdata->usus) {
if (!gpio_is_valid(pdata->usus)) {
dev_err(dev, "Invalid pin: usus.\n");
ret = -EINVAL;
goto err;
}
}注册DC充电的设备文件
mutex_init(&data->work_lock);
data->fault = false;
data->ta_in = ta_in;
data->usb_in = usb_in;
data->psy.name = "max8903-ac";
data->psy.type = POWER_SUPPLY_TYPE_MAINS;
data->psy.get_property = max8903_get_property;
data->psy.properties = max8903_charger_props;
data->psy.num_properties = ARRAY_SIZE(max8903_charger_props);
ret = power_supply_register(dev, &data->psy);
if (ret) {
dev_err(dev, "failed: power supply register.\n");
goto err_psy;
}注册USB充电的设备文件
data->usb.name = "max8903-usb";
data->usb.type = POWER_SUPPLY_TYPE_USB;
data->usb.get_property = max8903_get_usb_property;
data->usb.properties = max8903_charger_props;
data->usb.num_properties = ARRAY_SIZE(max8903_charger_props);
ret = power_supply_register(dev, &data->usb);
if (ret) {
dev_err(dev, "failed: power supply register.\n");
goto err_psy;
}这两个设备文件都只有一个操作：检测充电器是否在线
static enum power_supply_property max8903_charger_props[] = {
POWER_SUPPLY_PROP_ONLINE,
};操作函数也很简单
static int max8903_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max8903_data *data = container_of(psy,
struct max8903_data, psy);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = 0;
if (data->ta_in)
val->intval = 1;
data->charger_online = val->intval;
break;
default:
return -EINVAL;
}
return 0;
}
static int max8903_get_usb_property(struct power_supply *usb,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max8903_data *data = container_of(usb,
struct max8903_data, usb);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = 0;
if (data->usb_in)
val->intval = 1;
data->usb_charger_online = val->intval;
break;
default:
return -EINVAL;
}
return 0;
}我们可以通过/sys/devices/platform/max8903-charger.1/power_supply/max8903-ac 目录和/sys/devices/platform/max8903-charger.1/power_supply/max8903-usb目录下的设备文件来访问充电器的状态
接下来是IO中断
if (pdata->dc_valid) {
ret = request_threaded_irq(gpio_to_irq(pdata->dok),
NULL, max8903_dcin,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"MAX8903 DC IN", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for DC (%d)\n",
gpio_to_irq(pdata->dok), ret);
goto err_usb_irq;
}
}
if (pdata->usb_valid) {
ret = request_threaded_irq(gpio_to_irq(pdata->uok),
NULL, max8903_usbin,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"MAX8903 USB IN", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for USB (%d)\n",
gpio_to_irq(pdata->uok), ret);
goto err_dc_irq;
}
}
if (pdata->flt) {
ret = request_threaded_irq(gpio_to_irq(pdata->flt),
NULL, max8903_fault,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"MAX8903 Fault", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
gpio_to_irq(pdata->flt), ret);
goto err_flt_irq;
}
}
if (pdata->chg) {
ret = request_threaded_irq(gpio_to_irq(pdata->chg),
NULL, max8903_chg,
IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,
"MAX8903 Fault", data);
if (ret) {
dev_err(dev, "Cannot request irq %d for Fault (%d)\n",
gpio_to_irq(pdata->flt), ret);
goto err_chg_irq;
}
}这4个IO的中断处理函数很类似
static irqreturn_t max8903_dcin(int irq, void *_data)
{
struct max8903_data *data = _data;
struct max8903_pdata *pdata = data->pdata;
bool ta_in;
ta_in = gpio_get_value(pdata->dok) ? false : true; //保存当前dok值
if (ta_in == data->ta_in)
return IRQ_HANDLED;
data->ta_in = ta_in;
pr_info("TA(DC-IN) Charger %s.\n", ta_in ?
"Connected" : "Disconnected");
max8903_charger_update_status(data);
max8903_battery_update_status(data);
power_supply_changed(&data->psy); //报告状态改变
power_supply_changed(&data->bat);
return IRQ_HANDLED;
}
static irqreturn_t max8903_usbin(int irq, void *_data)
{
struct max8903_data *data = _data;
struct max8903_pdata *pdata = data->pdata;
bool usb_in;
usb_in = gpio_get_value(pdata->uok) ? false : true; //保存当前uok值
if (usb_in == data->usb_in)
return IRQ_HANDLED;
data->usb_in = usb_in;
max8903_charger_update_status(data);
max8903_battery_update_status(data);
pr_info("USB Charger %s.\n", usb_in ?
"Connected" : "Disconnected");
power_supply_changed(&data->bat);
power_supply_changed(&data->usb); //报告状态改变
return IRQ_HANDLED;
}
static irqreturn_t max8903_fault(int irq, void *_data)
{
struct max8903_data *data = _data;
struct max8903_pdata *pdata = data->pdata;
bool fault;
fault = gpio_get_value(pdata->flt) ? false : true; //保存当前电池错误值
if (fault == data->fault)
return IRQ_HANDLED;
data->fault = fault;
if (fault)
dev_err(data->dev, "Charger suffers a fault and stops.\n");
else
dev_err(data->dev, "Charger recovered from a fault.\n");
max8903_charger_update_status(data);
max8903_battery_update_status(data);
power_supply_changed(&data->psy);
power_supply_changed(&data->bat);
power_supply_changed(&data->usb); //报告状态改变
return IRQ_HANDLED;
}
static irqreturn_t max8903_chg(int irq, void *_data)
{
struct max8903_data *data = _data;
struct max8903_pdata *pdata = data->pdata;
int chg_state;
chg_state = gpio_get_value(pdata->chg) ? false : true;//保存电池充电状态
if (chg_state == data->chg_state)
return IRQ_HANDLED;
data->chg_state = chg_state;
max8903_charger_update_status(data);
max8903_battery_update_status(data);
power_supply_changed(&data->psy);
power_supply_changed(&data->bat);
power_supply_changed(&data->usb);//报告状态改变
return IRQ_HANDLED;
}到了这里电池充电的流程就走完了。