[PATCH 2/2] power: supply: Introduce the BQ27561 Fuel gauge driver

[Dan Murphy]

Introduce the BQ27561 Fuel gauge driver from Texas Instruments.  The
driver also supports the BQ27750 as it has the same register map and
bit mask.

Signed-off-by: Dan Murphy <dmurphy@xxxxxx>
---
 drivers/power/supply/Kconfig      |   9 +
 drivers/power/supply/Makefile     |   1 +
 drivers/power/supply/bq27561_fg.c | 304 ++++++++++++++++++++++++++++++
 3 files changed, 314 insertions(+)
 create mode 100644 drivers/power/supply/bq27561_fg.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index f3424fdce341..febf6bf8c4ea 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -597,6 +597,15 @@ config CHARGER_BQ25890
 	help
 	  Say Y to enable support for the TI BQ25890 battery charger.
 
+config FUEL_GAUGE_BQ27561
+	tristate "Texas Instruments bq27561 fuel gauge driver"
+	depends on I2C
+	select REGMAP_I2C
+	depends on GPIOLIB || COMPILE_TEST
+	help
+	 Say Y here to enable support for fuel gauge with TI bq27561
+	 fuel gauge chips.
+
 config CHARGER_SMB347
 	tristate "Summit Microelectronics SMB347 Battery Charger"
 	depends on I2C
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 6c7da920ea83..4e402292b276 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -81,6 +81,7 @@ obj-$(CONFIG_CHARGER_BQ24190)	+= bq24190_charger.o
 obj-$(CONFIG_CHARGER_BQ24257)	+= bq24257_charger.o
 obj-$(CONFIG_CHARGER_BQ24735)	+= bq24735-charger.o
 obj-$(CONFIG_CHARGER_BQ25890)	+= bq25890_charger.o
+obj-$(CONFIG_FUEL_GAUGE_BQ27561)	+= bq27561_fg.o
 obj-$(CONFIG_CHARGER_SMB347)	+= smb347-charger.o
 obj-$(CONFIG_CHARGER_TPS65090)	+= tps65090-charger.o
 obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
diff --git a/drivers/power/supply/bq27561_fg.c b/drivers/power/supply/bq27561_fg.c
new file mode 100644
index 000000000000..b9f7cdc00d2e
--- /dev/null
+++ b/drivers/power/supply/bq27561_fg.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0
+// BQ27561 Fuel Gauge Driver
+// Copyright (C) 2020 Texas Instruments Incorporated - http://www.ti.com/
+// Author: Dan Murphy <dmurphy@xxxxxx>
+
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/power_supply.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/moduleparam.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+
+#define BQ27561_REG_CNTL	0x00
+#define BQ27561_REG_AR		0x02
+#define BQ27561_REG_TEMP	0x06
+#define BQ27561_REG_VOLT	0x08
+#define BQ27561_REG_REMAIN_CAP	0x10
+#define BQ27561_REG_BATTSTAT	0x0a
+#define BQ27561_REG_CURRENT	0x0c
+#define BQ27561_REG_FCC		0x12
+#define BQ27561_REG_AVG_CURRENT	0x14
+#define BQ27561_REG_TTE		0x16
+#define BQ27561_REG_TTF		0x18
+#define BQ27561_REG_CYCLECNT	0x2a
+#define BQ27561_REG_RSOC	0x2c
+
+#define BQ27561_VAL_MULTIPLIER	1000
+#define BQ27561_TEMP_K_TO_C	2732
+#define BQ27561_TIME_MIN_TO_S	60
+
+#define BQ27561_BATT_DEPLETED	BIT(4)
+#define BQ27561_BATT_CHARGED	BIT(5)
+#define BQ27561_BATT_DISCHARGING	BIT(6)
+
+enum {
+	BQ27561,
+	BQ27750,
+};
+
+struct bq27561_device {
+	struct device *dev;
+	struct i2c_client *client;
+	struct power_supply *battery;
+};
+
+static enum power_supply_property bq27561_properties[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
+};
+
+static int bq27561_get_temp(struct bq27561_device *bq)
+{
+	unsigned int temp;
+
+	temp = i2c_smbus_read_word_data(bq->client, BQ27561_REG_TEMP);
+	if (temp < 0)
+		return temp;
+
+	return temp - BQ27561_TEMP_K_TO_C;
+}
+
+static int bq27561_get_voltage(struct bq27561_device *bq)
+{
+	unsigned int batt_volt;
+
+	batt_volt = i2c_smbus_read_word_data(bq->client, BQ27561_REG_VOLT);
+	if (batt_volt < 0)
+		return batt_volt;
+
+	return batt_volt * BQ27561_VAL_MULTIPLIER;
+}
+
+static int bq27561_get_current(struct bq27561_device *bq)
+{
+	unsigned int batt_curr;
+
+	batt_curr = i2c_smbus_read_word_data(bq->client, BQ27561_REG_CURRENT);
+	if (batt_curr < 0)
+		return batt_curr;
+
+	return batt_curr * BQ27561_VAL_MULTIPLIER;
+}
+
+static int bq27561_get_charge_capacity(struct bq27561_device *bq)
+{
+	unsigned int charge_cap;
+
+	charge_cap = i2c_smbus_read_word_data(bq->client, BQ27561_REG_FCC);
+	if (charge_cap < 0)
+		return charge_cap;
+
+	return charge_cap * BQ27561_VAL_MULTIPLIER;
+}
+
+static int bq27561_get_batt_status(struct bq27561_device *bq)
+{
+	unsigned int batt_stat;
+	unsigned int curr;
+	int ret;
+
+	batt_stat = i2c_smbus_read_word_data(bq->client, BQ27561_REG_BATTSTAT);
+	if (batt_stat < 0)
+		return batt_stat;
+
+	curr = i2c_smbus_read_word_data(bq->client, BQ27561_REG_CURRENT);
+	if (curr < 0)
+		return curr;
+
+	if (batt_stat & BQ27561_BATT_CHARGED)
+		ret = POWER_SUPPLY_STATUS_FULL;
+	else if (batt_stat & BQ27561_BATT_DISCHARGING || curr == 0)
+		ret = POWER_SUPPLY_STATUS_DISCHARGING;
+	else if (curr > 0)
+		ret = POWER_SUPPLY_STATUS_CHARGING;
+	else
+		ret = POWER_SUPPLY_STATUS_UNKNOWN;
+
+	return ret;
+}
+
+static int bq27561_get_empty_time(struct bq27561_device *bq)
+{
+	unsigned int empty_time;
+
+	empty_time = i2c_smbus_read_word_data(bq->client, BQ27561_REG_TTE);
+	if (empty_time < 0)
+		return empty_time;
+
+	return empty_time * BQ27561_TIME_MIN_TO_S;
+}
+
+static int bq27561_get_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				union power_supply_propval *val)
+{
+	struct bq27561_device *bq = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = bq27561_get_voltage(bq);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = bq27561_get_current(bq);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_STATUS:
+		ret = bq27561_get_batt_status(bq);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		val->intval = bq27561_get_temp(bq);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		ret = i2c_smbus_read_word_data(bq->client, BQ27561_REG_RSOC);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+		ret = bq27561_get_charge_capacity(bq);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
+		ret = bq27561_get_empty_time(bq);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		ret = i2c_smbus_read_word_data(bq->client, BQ27561_REG_AR);
+		if (ret < 0)
+			return ret;
+
+		val->intval = ret;
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	return 0;
+}
+
+static int bq27561_set_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				const union power_supply_propval *val)
+{
+	struct bq27561_device *bq = power_supply_get_drvdata(psy);
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		ret = i2c_smbus_write_word_data(bq->client, BQ27561_REG_AR,
+						val->intval);
+		break;
+	default:
+		return -EINVAL;
+	};
+
+	return ret;
+}
+
+static int bq27561_prop_is_writeable(struct power_supply *psy,
+				     enum power_supply_property prop)
+{
+	switch (prop) {
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+		return 1;
+	default:
+		return 0;
+	};
+}
+
+static struct power_supply_desc bq27561_power_supply_desc = {
+	.type = POWER_SUPPLY_TYPE_BATTERY,
+	.properties = bq27561_properties,
+	.num_properties = ARRAY_SIZE(bq27561_properties),
+	.get_property = bq27561_get_property,
+	.set_property = bq27561_set_property,
+	.property_is_writeable = bq27561_prop_is_writeable,
+};
+
+static int bq27561_probe(struct i2c_client *client,
+				 const struct i2c_device_id *id)
+{
+	struct bq27561_device *bq;
+	struct power_supply_config psy_cfg;
+
+	bq = devm_kzalloc(&client->dev, sizeof(*bq), GFP_KERNEL);
+	if (!bq)
+		return -ENOMEM;
+
+	bq->dev = &client->dev;
+	bq->client = client;
+	i2c_set_clientdata(client, bq);
+
+	psy_cfg.drv_data = bq;
+	bq27561_power_supply_desc.name = id->name;
+	bq->battery = devm_power_supply_register(bq->dev,
+						 &bq27561_power_supply_desc,
+						 &psy_cfg);
+
+	if (IS_ERR(bq->battery))
+		return -EINVAL;
+
+	return 0;
+}
+
+static const struct of_device_id bq27561_match_table[] = {
+	{.compatible = "ti,bq27561",},
+	{.compatible = "ti,bq27750",},
+	{},
+};
+MODULE_DEVICE_TABLE(of, bq_fg_match_table);
+
+static const struct i2c_device_id bq27561_id[] = {
+	{"bq27561", BQ27561},
+	{"bq27750", BQ27750},
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, bq27561_id);
+
+static struct i2c_driver bq27561_battery_driver = {
+	.driver = {
+		   .name = "bq27561-fuel-gauge",
+		   .of_match_table = bq27561_match_table,
+		   .owner = THIS_MODULE,
+		   },
+	.probe = bq27561_probe,
+	.id_table = bq27561_id,
+};
+module_i2c_driver(bq27561_battery_driver);
+
+MODULE_AUTHOR("Texas Instruments");
+MODULE_DESCRIPTION("bq27561 battery monitor driver");
+MODULE_LICENSE("GPL v2");
-- 
2.25.1