#include <linux/module.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/power_supply.h>
#include <linux/devm-helpers.h>
#define MAX14656_MANUFACTURER "Maxim Integrated"
#define MAX14656_NAME "max14656"
#define MAX14656_DEVICE_ID 0x00
#define MAX14656_INTERRUPT_1 0x01
#define MAX14656_INTERRUPT_2 0x02
#define MAX14656_STATUS_1 0x03
#define MAX14656_STATUS_2 0x04
#define MAX14656_INTMASK_1 0x05
#define MAX14656_INTMASK_2 0x06
#define MAX14656_CONTROL_1 0x07
#define MAX14656_CONTROL_2 0x08
#define MAX14656_CONTROL_3 0x09
#define DEVICE_VENDOR_MASK 0xf0
#define DEVICE_REV_MASK 0x0f
#define INT_EN_REG_MASK BIT(4)
#define CHG_TYPE_INT_MASK BIT(0)
#define STATUS1_VB_VALID_MASK BIT(4)
#define STATUS1_CHG_TYPE_MASK 0xf
#define INT1_DCD_TIMEOUT_MASK BIT(7)
#define CONTROL1_DEFAULT 0x0d
#define CONTROL1_INT_EN BIT(4)
#define CONTROL1_INT_ACTIVE_HIGH BIT(5)
#define CONTROL1_EDGE BIT(7)
#define CONTROL2_DEFAULT 0x8e
#define CONTROL2_ADC_EN BIT(0)
#define CONTROL3_DEFAULT 0x8d
enum max14656_chg_type {
MAX14656_NO_CHARGER = 0,
MAX14656_SDP_CHARGER,
MAX14656_CDP_CHARGER,
MAX14656_DCP_CHARGER,
MAX14656_APPLE_500MA_CHARGER,
MAX14656_APPLE_1A_CHARGER,
MAX14656_APPLE_2A_CHARGER,
MAX14656_SPECIAL_500MA_CHARGER,
MAX14656_APPLE_12W,
MAX14656_CHARGER_LAST
};
static const struct max14656_chg_type_props {
enum power_supply_type type;
} chg_type_props[] = {
{ POWER_SUPPLY_TYPE_UNKNOWN },
{ POWER_SUPPLY_TYPE_USB },
{ POWER_SUPPLY_TYPE_USB_CDP },
{ POWER_SUPPLY_TYPE_USB_DCP },
{ POWER_SUPPLY_TYPE_USB_DCP },
{ POWER_SUPPLY_TYPE_USB_DCP },
{ POWER_SUPPLY_TYPE_USB_DCP },
{ POWER_SUPPLY_TYPE_USB_DCP },
{ POWER_SUPPLY_TYPE_USB },
};
struct max14656_chip {
struct i2c_client *client;
struct power_supply *detect_psy;
struct power_supply_desc psy_desc;
struct delayed_work irq_work;
int irq;
int online;
};
static int max14656_read_reg(struct i2c_client *client, int reg, u8 *val)
{
s32 ret;
ret = i2c_smbus_read_byte_data(client, reg);
if (ret < 0) {
dev_err(&client->dev,
"i2c read fail: can't read from %02x: %d\n",
reg, ret);
return ret;
}
*val = ret;
return 0;
}
static int max14656_write_reg(struct i2c_client *client, int reg, u8 val)
{
s32 ret;
ret = i2c_smbus_write_byte_data(client, reg, val);
if (ret < 0) {
dev_err(&client->dev,
"i2c write fail: can't write %02x to %02x: %d\n",
val, reg, ret);
return ret;
}
return 0;
}
static int max14656_read_block_reg(struct i2c_client *client, u8 reg,
u8 length, u8 *val)
{
int ret;
ret = i2c_smbus_read_i2c_block_data(client, reg, length, val);
if (ret < 0) {
dev_err(&client->dev, "failed to block read reg 0x%x: %d\n",
reg, ret);
return ret;
}
return 0;
}
#define REG_TOTAL_NUM 5
static void max14656_irq_worker(struct work_struct *work)
{
struct max14656_chip *chip =
container_of(work, struct max14656_chip, irq_work.work);
u8 buf[REG_TOTAL_NUM];
u8 chg_type;
max14656_read_block_reg(chip->client, MAX14656_DEVICE_ID,
REG_TOTAL_NUM, buf);
if ((buf[MAX14656_STATUS_1] & STATUS1_VB_VALID_MASK) &&
(buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK)) {
chg_type = buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK;
if (chg_type < MAX14656_CHARGER_LAST)
chip->psy_desc.type = chg_type_props[chg_type].type;
else
chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
chip->online = 1;
} else {
chip->online = 0;
chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
}
power_supply_changed(chip->detect_psy);
}
static irqreturn_t max14656_irq(int irq, void *dev_id)
{
struct max14656_chip *chip = dev_id;
schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(100));
return IRQ_HANDLED;
}
static int max14656_hw_init(struct max14656_chip *chip)
{
uint8_t val = 0;
uint8_t rev;
struct i2c_client *client = chip->client;
if (max14656_read_reg(client, MAX14656_DEVICE_ID, &val))
return -ENODEV;
if ((val & DEVICE_VENDOR_MASK) != 0x20) {
dev_err(&client->dev, "wrong vendor ID %d\n",
((val & DEVICE_VENDOR_MASK) >> 4));
return -ENODEV;
}
rev = val & DEVICE_REV_MASK;
if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
return -EINVAL;
if (max14656_write_reg(client, MAX14656_CONTROL_1,
CONTROL1_DEFAULT |
CONTROL1_INT_EN |
CONTROL1_INT_ACTIVE_HIGH |
CONTROL1_EDGE))
return -EINVAL;
if (max14656_write_reg(client, MAX14656_INTMASK_1, 0x3))
return -EINVAL;
if (max14656_write_reg(client, MAX14656_INTMASK_2, 0x1))
return -EINVAL;
dev_info(&client->dev, "detected revision %d\n", rev);
return 0;
}
static int max14656_get_property(struct power_supply *psy,
enum power_supply_property psp,
union power_supply_propval *val)
{
struct max14656_chip *chip = power_supply_get_drvdata(psy);
switch (psp) {
case POWER_SUPPLY_PROP_ONLINE:
val->intval = chip->online;
break;
case POWER_SUPPLY_PROP_MODEL_NAME:
val->strval = MAX14656_NAME;
break;
case POWER_SUPPLY_PROP_MANUFACTURER:
val->strval = MAX14656_MANUFACTURER;
break;
default:
return -EINVAL;
}
return 0;
}
static enum power_supply_property max14656_battery_props[] = {
POWER_SUPPLY_PROP_ONLINE,
POWER_SUPPLY_PROP_MODEL_NAME,
POWER_SUPPLY_PROP_MANUFACTURER,
};
static int max14656_probe(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
struct device *dev = &client->dev;
struct power_supply_config psy_cfg = {};
struct max14656_chip *chip;
int irq = client->irq;
int ret = 0;
if (irq <= 0) {
dev_err(dev, "invalid irq number: %d\n", irq);
return -ENODEV;
}
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
return -ENODEV;
}
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
psy_cfg.drv_data = chip;
chip->client = client;
chip->online = 0;
chip->psy_desc.name = MAX14656_NAME;
chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
chip->psy_desc.properties = max14656_battery_props;
chip->psy_desc.num_properties = ARRAY_SIZE(max14656_battery_props);
chip->psy_desc.get_property = max14656_get_property;
chip->irq = irq;
ret = max14656_hw_init(chip);
if (ret)
return -ENODEV;
chip->detect_psy = devm_power_supply_register(dev,
&chip->psy_desc, &psy_cfg);
if (IS_ERR(chip->detect_psy)) {
dev_err(dev, "power_supply_register failed\n");
return -EINVAL;
}
ret = devm_delayed_work_autocancel(dev, &chip->irq_work,
max14656_irq_worker);
if (ret) {
dev_err(dev, "devm_delayed_work_autocancel %d failed\n", ret);
return ret;
}
ret = devm_request_irq(dev, chip->irq, max14656_irq,
IRQF_TRIGGER_FALLING,
MAX14656_NAME, chip);
if (ret) {
dev_err(dev, "request_irq %d failed\n", chip->irq);
return -EINVAL;
}
enable_irq_wake(chip->irq);
schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
return 0;
}
static const struct i2c_device_id max14656_id[] = {
{ .name = "max14656" },
{ }
};
MODULE_DEVICE_TABLE(i2c, max14656_id);
static const struct of_device_id max14656_match_table[] = {
{ .compatible = "maxim,max14656", },
{}
};
MODULE_DEVICE_TABLE(of, max14656_match_table);
static struct i2c_driver max14656_i2c_driver = {
.driver = {
.name = "max14656",
.of_match_table = max14656_match_table,
},
.probe = max14656_probe,
.id_table = max14656_id,
};
module_i2c_driver(max14656_i2c_driver);
MODULE_DESCRIPTION("MAX14656 USB charger detector");
MODULE_LICENSE("GPL v2");
