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android电池驱动(五)(自用)

2015-07-27 10:59 519 查看
关键词:android 电池 电量计 PL2301任务初始化宏 power_supply 中断线程化

平台信息:

内核:linux2.6/linux3.0

系统:android/android4.0

平台:samsung exynos 4210、exynos 4412 、exynos 5250


完整驱动代码&规格书下载:MAX17040_PL2301

android 电池(一):锂电池基本原理篇



android 电池(二):android关机充电流程、充电画面显示



android 电池(三):android电池系统

android电池(四):电池 电量计(MAX17040)驱动分析篇
android电池(五):电池 充电IC(PM2301)驱动分析篇

android充电这块,有的电源管理芯片内部包含充电管理,如s5pv210上常用的AT8937。我们这次用的max77686没有充电控制这块,所以我们加入一个充电IC来控制,选用PM2301.

一、PM2301和主控、电池的逻辑

如下图所示:



1、蓝色部分:IIC控制接口,这个说得太多了,好多外围器件都是通过IIC控制的,这个一定要熟悉、熟悉、熟烂了,然后可以完成比较多的工作。

2、黄色部分:中断、使能控制脚,CHG_STATUS(IRQ)、 DC_IN_INT(WAKE_UP) 、 PM2301_LP(LPN)、CHARGER_EN(ENN)控制引脚;

IRQ:充电IC的状态,如果有动作通知主控;

WAKE_UP:如果有DC插入,产生中断通知主控;

LPN:

ENN:充电IC使能;

3、PM2301 、电池、系统电压的大致逻辑

标号1:系统电压有PM2301提供;

标号2:PM2301给电池充电;

标号3:系统电压有电池提供;

标号:1和标号:3不同时提供电压给系统,中间有一个MOS管切换;分两种情况:

(1)、不插充电器时,有电池提供电压给系统,走通道标号:3给系统供电;

(2)、插入DC后,系统侦测到DC插入,把3的通道关闭,打开1给系统供电,同时有2给电池充电;

二、PM2301硬件电路

如下所示:



Q5这个MOS管,就是控制系统供电的,没有充电时,VBATT有VBAT+提供,充电时,VBATT有SENSE_COMM提供。

控制脚对应主控的引脚:
IIC

IIC ID 为2

CHG_STATUS(IRQ)

EXYNOS4_GPX1(3)

DC_IN_INT(WAKE_UP)

EXYNOS4_GPX0(7)

PM2301_LP(LPN)

EXYNOS4_GPX1(7)

CHARGER_EN(ENN)

EXYNOS4_GPL2(0)

下图为PM2301的参考电路解法,同样看到P1控制VSYSTEM电源部分的切换控制。



下图为整个电池充电的过程控制:

Trickle mode、Constant current mode (CC mode or fast charge mode)、Constant voltage mode (CV mode) 、End of charge feature



三、PL2301驱动部分

PL2301的硬件、工作原理做简单的解释,接下来我们分析驱动程序:

驱动用到知识点:

IIC的注册;

任务初始化宏(在上一篇我们简单提过);

中断线程化;

1、IIC的注册

这个和上一篇所说的电量计相似;

(1)、pm2301驱动部分

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static const struct i2c_device_id pm2301_id[] = {

{ "pm2301", 0 },

{ }

};

MODULE_DEVICE_TABLE(i2c, pm2301_id);

static struct i2c_driver pm2301_i2c_driver = {

.driver = {

.name = "pm2301",

},

.probe = pm2301_probe,

.remove = __devexit_p(pm2301_remove),

.suspend = pm2301_suspend,

.resume = pm2301_resume,

.id_table = pm2301_id,

};

static int __init pm2301_init(void)

{

printk(KERN_INFO "pm2301_init !!\n");

return i2c_add_driver(&pm2301_i2c_driver);

}

module_init(pm2301_init);

(2)、平台驱动部分

arch/arm/mach-exynos/mach-smdk4x12.c

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static struct i2c_board_info i2c_devs1[] __initdata = {

…………

#ifdef CONFIG_CHARGER_PM2301

{

I2C_BOARD_INFO("pm2301", 0x2c),

.platform_data = &pm2301_platform_data,

},

#endif

…………

};

下图就是我们IIC驱动注册生成的文件;

/sys/bus/i2c/drivers/pm2301



2、关于:pm2301_platform_data这个结构体

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static struct pm2301_platform_data pm2301_platform_data = {

.hw_init = pm2301_hw_init,//(1)、硬件接口初始化化;

.gpio_lpn = GPIO_PM2301_LP,//(2)、结构体初始化;

.gpio_irq = GPIO_CHARGER_STATUS,

.gpio_enn = GPIO_CHARGER_ENABLE,

.gpio_wakeup = GPIO_CHARGER_ONLINE,

};

arch/arm/mach-exynos/mach-smdk4x12.c

(1)、硬件接口初始化

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static int pm2301_hw_init(void)

{

printk("pm2301_hw_init !!\n");

if (gpio_request(GPIO_CHARGER_ONLINE, "GPIO_CHARGER_ONLINE")) {

printk(KERN_ERR "%s :GPIO_CHARGER_ONLINE request port error!\n", __func__);

goto err_gpio_failed;

} else {

s3c_gpio_setpull(GPIO_CHARGER_ONLINE, S3C_GPIO_PULL_NONE);

s3c_gpio_cfgpin(GPIO_CHARGER_ONLINE, S3C_GPIO_SFN(0));

gpio_direction_input(GPIO_CHARGER_ONLINE);

gpio_free(GPIO_CHARGER_ONLINE);

}

if (gpio_request(GPIO_CHARGER_STATUS, "GPIO_CHARGER_STATUS")) {

printk(KERN_ERR "%s :GPIO_CHARGER_STATUS request port error!\n", __func__);

goto err_gpio_failed;

} else {

s3c_gpio_setpull(GPIO_CHARGER_STATUS, S3C_GPIO_PULL_NONE);

s3c_gpio_cfgpin(GPIO_CHARGER_STATUS, S3C_GPIO_SFN(0));

gpio_direction_input(GPIO_CHARGER_STATUS);

gpio_free(GPIO_CHARGER_STATUS);

}

if (gpio_request(GPIO_CHARGER_ENABLE, "GPIO_CHARGER_ENABLE")) {

printk(KERN_ERR "%s :GPIO_CHARGER_ENABLE request port error!\n", __func__);

goto err_gpio_failed;

} else {

s3c_gpio_setpull(GPIO_CHARGER_ENABLE, S3C_GPIO_PULL_NONE);

s3c_gpio_cfgpin(GPIO_CHARGER_ENABLE, S3C_GPIO_SFN(1));

gpio_direction_output(GPIO_CHARGER_ENABLE, 0);

gpio_free(GPIO_CHARGER_ENABLE);

}

if (gpio_request(GPIO_PM2301_LP, "GPIO_PM2301_LP")) {

printk(KERN_ERR "%s :GPIO_PM2301_LP request port error!\n", __func__);

goto err_gpio_failed;

} else {

s3c_gpio_setpull(GPIO_PM2301_LP, S3C_GPIO_PULL_NONE);

s3c_gpio_cfgpin(GPIO_PM2301_LP, S3C_GPIO_SFN(1));

gpio_direction_output(GPIO_PM2301_LP, 1);

gpio_free(GPIO_PM2301_LP);

}

return 1;

err_gpio_failed:

return 0;

}

(2)、结构体初始化

Include/linux/pm2301_charger.h

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#define GPIO_CHARGER_ONLINE EXYNOS4_GPX0(7)//对应控制脚的主控接口

#define GPIO_CHARGER_STATUS EXYNOS4_GPX1(3)

#define GPIO_CHARGER_ENABLE EXYNOS4_GPL2(0)

#define GPIO_PM2301_LP EXYNOS4_GPX1(7)

struct pm2301_platform_data {

int (*hw_init)(void);

int gpio_enn;

int gpio_wakeup;

int gpio_irq;

int gpio_lpn;

};

extern int pm2301_get_online(void);

extern int pm2301_get_status(void);

3、probe函数分析

如果你是初学者,建议多看程序,你会发现,其实驱动程序的格式大多都是相同的,如这个IIC 器件的, 队列、定时器之类的东西。

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static int __devinit pm2301_probe(struct i2c_client *client,

const struct i2c_device_id *id)

{

struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);

struct pm2301_chip *chip;

int ret;

printk(KERN_INFO "PM2301 probe !!\n");

//(1)、前面这部分是对IIC的初始化;

if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))

return -EIO;

chip = kzalloc(sizeof(*chip), GFP_KERNEL);

if (!chip)

return -ENOMEM;

g_chip = chip;

chip->client = client;

chip->pdata = client->dev.platform_data;

i2c_set_clientdata(client, chip);

/* Hardware Init for PM2301 */

if (chip->pdata->hw_init && !(chip->pdata->hw_init())) {

dev_err(&client->dev, "hardware initial failed.\n");

goto err_hw_failed;

}

mutex_init(&i2c_lock);

//(2)、初始化两个队列

INIT_DELAYED_WORK_DEFERRABLE(&chip->work_online, pm2301_online_work);

INIT_DELAYED_WORK_DEFERRABLE(&chip->work_status, pm2301_ststus_work);

//(3)、中断线程化

chip->irq_online = gpio_to_irq(chip->pdata->gpio_wakeup);

chip->irq_status = gpio_to_irq(chip->pdata->gpio_irq);

/* Request IRQ for PM2301 */

ret = request_threaded_irq(chip->irq_online,

NULL, pm2301_dcin,

IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,

"PM2301 DC IN", chip);

if (ret) {

printk(KERN_ERR "Cannot request irq %d for DC (%d)\n",

chip->irq_online, ret);

goto err_hw_failed;

}

#ifdef PM2301_REPORT_STATUS_BY_IRQ

ret = request_threaded_irq(chip->irq_status,

NULL, pm2301_status,

IRQF_TRIGGER_FALLING,

"PM2301 STATUS", chip);

if (ret) {

printk(KERN_ERR "Cannot request irq %d for CHARGE STATUS (%d)\n",

chip->irq_status, ret);

goto err_hw_failed;

}

#endif

charger_initial = 1;

g_has_charged = 0;

g_has_charging_full_or_stop = 0;

#ifdef PM2301_REPORT_STATUS_BY_IRQ

/* Set wakeup source for online pin*/

irq_set_irq_wake(chip->irq_status, 1);

#endif

/* Set wakeup source for online pin*/

irq_set_irq_wake(chip->irq_online, 1);

/* Init default interrupt route for PM2301 */

pm2301_reg_init(chip->client);

/* Init online & status value */

chip->online = pm2301_charger_online(chip);

g_pm2301_online = chip->online; /* Sync to global */

pm2301_charger_enable(chip->client, chip->online);

pm2301_charger_status(chip);

printk(KERN_INFO "PM2301 probe success!!\n");

return 0;

err_hw_failed:

dev_err(&client->dev, "failed: power supply register\n");

i2c_set_clientdata(client, NULL);

kfree(chip);

return ret;

}

(1)、前面这部分是对IIC的初始化

这部分就不再多说了,搞来搞去都是这个老样子;

(2)、任务初始化宏

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INIT_DELAYED_WORK_DEFERRABLE(&chip->work_online, pm2301_online_work);

INIT_DELAYED_WORK_DEFERRABLE(&chip->work_status, pm2301_ststus_work);

把pm2301_online_work加入队列chip->work_online, pm2301_ststus_work加入chip->work_status队列。

(3)、中断线程化 request_threaded_irq

为什么要提出中断线程化?

在 Linux 中,中断具有最高的优先级。不论在任何时刻,只要产生中断事件,内核将立即执行相应的中断处理程序,等到所有挂起的中断和软中断处理完毕后才能执行正常的任务,因此有可能造成实时任务得不到及时的处理。中断线程化之后,中断将作为内核线程运行而且被赋予不同的实时优先级,实时任务可以有比中断线程更高的优先级。这样,具有最高优先级的实时任务就能得到优先处理,即使在严重负载下仍有实时性保证。但是,并不是所有的中断都可以被线程化,比如时钟中断,主要用来维护系统时间以及定时器等,其中定时器是操作系统的脉搏,一旦被线程化,就有可能被挂起,这样后果将不堪设想,所以不应当被线程化。

看下我们程序中如何把中断线程化的:

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chip->irq_online = gpio_to_irq(chip->pdata->gpio_wakeup);

chip->irq_status = gpio_to_irq(chip->pdata->gpio_irq);

看到这里是否想起:

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static struct pm2301_platform_data pm2301_platform_data = {

    ………………

.gpio_lpn = GPIO_PM2301_LP,

.gpio_irq = GPIO_CHARGER_STATUS,

.gpio_enn = GPIO_CHARGER_ENABLE,

.gpio_wakeup = GPIO_CHARGER_ONLINE,

};

#define GPIO_CHARGER_ONLINE EXYNOS4_GPX0(7)

#define GPIO_CHARGER_STATUS EXYNOS4_GPX1(3)

#define GPIO_CHARGER_ENABLE EXYNOS4_GPL2(0)

#define GPIO_PM2301_LP EXYNOS4_GPX1(7)

感觉申请个中断脚,这样有点费劲呀;

中断线程化:

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/* Request IRQ for PM2301 */

ret = request_threaded_irq(chip->irq_online,

NULL, pm2301_dcin,

IRQF_TRIGGER_FALLING | IRQF_TRIGGER_RISING,

"PM2301 DC IN", chip);

当有插入DC中断出发时调用:

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static irqreturn_t pm2301_dcin(int irq, void *_data)

{

struct pm2301_chip *chip = _data;

schedule_delayed_work(&chip->work_online, PM2301_DELAY);

return IRQ_HANDLED;

}

Pm2301_dcin调度队列:chip->work_online执行:pm2301_online_work函数

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static void pm2301_online_work(struct work_struct *work)

{

struct pm2301_chip *chip;

chip = container_of(work, struct pm2301_chip, work_online.work);

int new_online = pm2301_charger_online(chip);

if (chip->online != new_online) {

chip->online = new_online;

g_pm2301_online = chip->online; /* Sync to global */

pm2301_charger_enable(chip->client, chip->online);//①、初始化充电IC;

#ifdef PM2301_REPORT_STATUS_BY_IRQ

/*To avoid status pin keep low*/

schedule_delayed_work(&chip->work_status, 1000);

#endif

#if defined(CONFIG_BATTERY_MAX17040)

TriggerGasgaugeUpdate();//②、把DC状态更新到max17040;

#endif

}

}

①、初始化电IC

这里面主要是写一些寄存器

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static void pm2301_charger_enable(struct i2c_client *client, int online)

{

if (online) { /* Enabled Charging*/

int batt_capacity = 0;

batt_capacity = GetGasgaugeCapacity();

/* Don't start charging if battery capacity above 95% when DC plug in*/

if(0) {

//if( batt_capacity >= 95 ) {

pm2301_write_reg(client, 0x01, 0x02);

pm2301_write_reg(client, 0x26, 0x00); /* always keep the register to 0 */

} else {

pm2301_write_reg(client, 0x00, 0x01); /* force resume of charging */

pm2301_write_reg(client, 0x01, 0x06); /* ChEn=1, AutoResume=1 */

pm2301_write_reg(client, 0x05, 0x7A); /* ChEoccurrentLevel:150mA, ChPrechcurrentLevel:100mA, ChCCcurrentLevel:1000mA/2000mA */

pm2301_write_reg(client, 0x06, 0x0A); /* ChVersumeVot:3.6V ChPrechVoltLevel:2.9V */

pm2301_write_reg(client, 0x07, 0x1E); /* ChVoltLevel:4.25V */

pm2301_write_reg(client, 0x26, 0x00); /* always keep the register to 0 */

}

g_has_charged = 1;

} else { /* Disable Charging*/

pm2301_write_reg(client, 0x01, 0x02);

pm2301_write_reg(client, 0x26, 0x00); /* always keep the register to 0 */

g_has_charged = 0;

}

}

②、把DC状态更新到max17040

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TriggerGasgaugeUpdate()

插入DC这部流程如下:

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