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/* Register address */
#define VCELL_REG 0x02
#define SOCREP_REG 0x04
#define MISCCFG_REG 0x06
#define RCOMP_REG 0x0C
#define CMD_REG 0xFE
#include <linux/jiffies.h>
#include <linux/slab.h>
int fuel_guage_init;
EXPORT_SYMBOL(fuel_guage_init);
static struct i2c_driver fg_i2c_driver;
static struct i2c_client *fg_i2c_client;
struct fg_state{
struct i2c_client *client;
};
static int fg_i2c_read(struct i2c_client *client, u8 reg, u8 *data, u8 length)
{
int value = i2c_smbus_read_word_data(client, reg);
if (value < 0) {
pr_err("%s: Failed to fg_i2c_read\n", __func__);
return -1;
}
*data = value & 0x00ff;
*(data+1) = (value & 0xff00) >> 8;
return 0;
}
static int fg_i2c_write(struct i2c_client *client, u8 reg, u8 *data, u8 length)
{
u16 value = (*(data+1) << 8) | (*(data)) ;
return i2c_smbus_write_word_data(client, reg, value);
}
int fg_read_vcell(void)
{
struct i2c_client *client = fg_i2c_client;
u8 data[2];
u32 vcell = 0;
if (!fuel_guage_init) {
pr_err("%s : fuel guage IC is not initialized!!\n", __func__);
return -1;
}
if (fg_i2c_read(client, VCELL_REG, data, 2) < 0) {
pr_err("%s: Failed to read VCELL\n", __func__);
return -1;
}
vcell = ((((data[0] << 4) & 0xFF0) | ((data[1] >> 4) & 0xF)) * 125)/100;
return vcell;
}
int fg_read_soc(void)
{
struct i2c_client *client = fg_i2c_client;
u8 data[2];
u32 soc = 0;
u32 temp = 0;
u32 temp_soc = 0;
if (!fuel_guage_init) {
pr_err("%s : fuel guage IC is not initialized!!\n", __func__);
return -1;
}
if (fg_i2c_read(client, SOCREP_REG, data, 2) < 0) {
pr_err("%s: Failed to read SOCREP\n", __func__);
return -1;
}
temp = data[0] * 100 + ((data[1] * 100) / 256);
if (temp >= 100)
temp_soc = temp;
else {
if (temp >= 70)
temp_soc = 100;
else
temp_soc = 0;
}
/* rounding off and Changing to percentage */
soc = temp_soc / 100;
if (temp_soc % 100 >= 50)
soc += 1;
if (soc >= 26)
soc += 4;
else
soc = (30 * temp_soc) / 26 / 100;
if (soc >= 100)
soc = 100;
return soc;
}
int fg_reset_soc(void)
{
struct i2c_client *client = fg_i2c_client;
u8 data[2];
s32 ret = 0;
if (!fuel_guage_init) {
pr_err("%s : fuel guage IC is not initialized!!\n", __func__);
return -1;
}
/* Quick-start */
data[0] = 0x40;
data[1] = 0x00;
if (fg_i2c_write(client, MISCCFG_REG, data, 2) < 0) {
pr_err("%s: Failed to write MiscCFG\n", __func__);
return -1;
}
msleep(500);
return ret;
}
void fuel_gauge_rcomp(void)
{
struct i2c_client *client = fg_i2c_client;
u8 rst_cmd[2];
if (!fuel_guage_init) {
pr_err("%s : fuel guage IC is not initialized!!\n", __func__);
return ;
}
rst_cmd[0] = 0xB0;
rst_cmd[1] = 0x00;
if (fg_i2c_write(client, RCOMP_REG, rst_cmd, 2) < 0)
pr_err("%s: failed fuel_gauge_rcomp\n", __func__);
}
static int fg_i2c_remove(struct i2c_client *client)
{
struct fg_state *fg = i2c_get_clientdata(client);
kfree(fg);
return 0;
}
static int fg_i2c_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct fg_state *fg;
fuel_guage_init = 0;
fg_i2c_client = NULL;
fg = kzalloc(sizeof(struct fg_state), GFP_KERNEL);
if (fg == NULL) {
pr_err("failed to allocate memory\n");
return -ENOMEM;
}
fg->client = client;
i2c_set_clientdata(client, fg);
/* rest of the initialisation goes here. */
pr_info("Fuel guage attach success!!!\n");
fg_i2c_client = client;
fuel_guage_init = 1;
return 0;
}
static const struct i2c_device_id fg_device_id[] = {
{"max1704x", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, fg_device_id);
static struct i2c_driver fg_i2c_driver = {
.driver = {
.name = "max1704x",
.owner = THIS_MODULE,
},
.probe = fg_i2c_probe,
.remove = fg_i2c_remove,
.id_table = fg_device_id,
};
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