外部电量计驱动代码，直接上代码了，懒，不做细节分析。。。。。

/** Fuelgauge battery driver** This package is free software; you can redistribute it and/or modify* it under the terms of the GNU General Public License version 2 as* published by the Free Software Foundation.** THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.*/#define pr_fmt(fmt)	"[hy4145] %s: " fmt, __func__
#include <linux/module.h>
#include <linux/param.h>
#include <linux/jiffies.h>
#include <linux/workqueue.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/gpio/consumer.h>#define sh_info	pr_info
#define sh_dbg	pr_debug
#define sh_err	pr_err
#define sh_log	pr_err#define	INVALID_REG_ADDR	0xFF
#define SHFS_UPDATE_KEY		0x8F91#define SH_FG_I2C_DEV_ADDR    (0x0b >> 1)
#define hy4145_ADDR 0x0b#define FG_FLAGS_FD				BIT(4)
#define	FG_FLAGS_FC				BIT(5)
#define	FG_FLAGS_DSG				BIT(6)
#define FG_FLAGS_RCA				BIT(9)#define DEBUG_INFO 0#if DEBUG_INFO#define debug(fmt,x...) printk("[hy4145]:-------------->%s(), line = %d " fmt,__FUNCTION__, __LINE__, ##x);
#else#define debug(fmt, x...)
#endifstruct sh_fg_chip* sh;	int charge_temp_value = 1000;
int charge_vlot_value = 0;
static int value_temp = 0;enum sh_fg_device {HY4145,
};static const unsigned char *device2str[] = {"hy4145",
};struct sh_fg_chip {struct device *dev;struct i2c_client *client;struct mutex update_lock;struct mutex irq_complete;bool resume_completed;u8 chip;struct power_supply *fg_psy;struct power_supply_desc fg_psy_d;};static int standard_command(struct i2c_client *client,unsigned char addr, unsigned char* buf)
{int ret = i2c_master_send(client, &addr, 1);if (ret < 0){pr_err("i2c_master_send error ret=%d\n", ret);return -1;}ret = i2c_master_recv(client, buf, 2);if (ret < 0){pr_err("i2c_master_recv error ret=%d\n", ret);return -1;}return 0;
}static int get_prop_status(struct sh_fg_chip *sh)
{unsigned char buf[2];standard_command(sh->client,0x00,buf);return buf[1]<<8|buf[0];
}st