I.MX6 bq27441 GPOUT interrupt

/********************************************************************
*                  I.MX6 bq27441 GPOUT interrupt
* 说明：
*     由于目前的bq27441驱动中没有GPOUT中断驱动，所以需要另外加上，其
* 中有参考TI的驱动，但是内核版本不一致，所以处理方式也不一致。
*
*                                  2016-7-15 深圳 南山平山村 曾剑锋
*******************************************************************/

一、参考文档：
a reasonable example of a work queue? http://www.spinics.net/lists/newbies/msg27303.html 
二、修改drivers/power/bq27x00_battery.c
......
#include <linux/interrupt.h>
#include <linux/gpio.h>

#define SABRESD_UAUGE_PIN        IMX_GPIO_NR(1, 29)

......

static void battery_irq(struct work_struct *unused);
static DECLARE_DELAYED_WORK(battery_irq_work, battery_irq);
struct bq27x00_device_info *battery_irq_work_di = NULL;

static void battery_irq(struct work_struct *unused)
{
if (battery_irq_work_di != NULL)
bq27x00_update(battery_irq_work_di);
}

static irqreturn_t bq27xxx_battery_irq_handler_thread(int irq, void *data)
{
struct bq27x00_device_info *di = data;
battery_irq_work_di = di;

schedule_delayed_work(&battery_irq_work, 0);

return IRQ_HANDLED;
}

......

static int __init bq27x00_battery_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
......
gpio_request(SABRESD_UAUGE_PIN, "sabresd_uauge_pin");
gpio_direction_input(SABRESD_UAUGE_PIN);
unsigned int irq = gpio_to_irq(SABRESD_UAUGE_PIN);
int ret = request_irq(irq, bq27xxx_battery_irq_handler_thread,
IRQF_TRIGGER_RISING,
"sabresd_uauge_pin", di);
enable_irq_wake(irq);
......
}