drivers/power/supply/sbs-manager.c - linux - Git at Google

 /*
  * Driver for SBS compliant Smart Battery System Managers
  *
  * The device communicates via i2c at address 0x0a and multiplexes access to up
  * to four smart batteries at address 0x0b.
  *
  * Via sysfs interface the online state and charge type are presented.
  *
  * Datasheet SBSM:    http://sbs-forum.org/specs/sbsm100b.pdf
  * Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf
  *
  * Karl-Heinz Schneider <karl-heinz@schneider-inet.de>
  *
  * This program 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.
  */

 #include <linux/gpio.h>
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/i2c-mux.h>
 #include <linux/power_supply.h>
 #include <linux/property.h>

 #define SBSM_MAX_BATS  4
 #define SBSM_RETRY_CNT 3

 /* registers addresses */
 #define SBSM_CMD_BATSYSSTATE     0x01
 #define SBSM_CMD_BATSYSSTATECONT 0x02
 #define SBSM_CMD_BATSYSINFO      0x04
 #define SBSM_CMD_LTC             0x3c

 #define SBSM_MASK_BAT_SUPPORTED  GENMASK(3, 0)
 #define SBSM_MASK_CHARGE_BAT     GENMASK(7, 4)
 #define SBSM_BIT_AC_PRESENT      BIT(0)
 #define SBSM_BIT_TURBO           BIT(7)

 #define SBSM_SMB_BAT_OFFSET      11
 struct sbsm_data {
 	struct i2c_client *client;
 	struct i2c_mux_core *muxc;

 	struct power_supply *psy;

 	u8 cur_chan;          /* currently selected channel */
 	struct gpio_chip chip;
 	bool is_ltc1760;      /* special capabilities */

 	unsigned int supported_bats;
 	unsigned int last_state;
 	unsigned int last_state_cont;
 };

 static enum power_supply_property sbsm_props[] = {
 	POWER_SUPPLY_PROP_ONLINE,
 	POWER_SUPPLY_PROP_CHARGE_TYPE,
 };

 static int sbsm_read_word(struct i2c_client *client, u8 address)
 {
 	int reg, retries;

 	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
 		reg = i2c_smbus_read_word_data(client, address);
 		if (reg >= 0)
 			break;
 	}

 	if (reg < 0) {
 		dev_err(&client->dev, "failed to read register 0x%02x\n",
 			address);
 	}

 	return reg;
 }

 static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
 {
 	int ret, retries;

 	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
 		ret = i2c_smbus_write_word_data(client, address, word);
 		if (ret >= 0)
 			break;
 	}
 	if (ret < 0)
 		dev_err(&client->dev, "failed to write to register 0x%02x\n",
 			address);

 	return ret;
 }

 static int sbsm_get_property(struct power_supply *psy,
 			     enum power_supply_property psp,
 			     union power_supply_propval *val)
 {
 	struct sbsm_data *data = power_supply_get_drvdata(psy);
 	int regval = 0;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_ONLINE:
 		regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT);
 		if (regval < 0)
 			return regval;
 		val->intval = !!(regval & SBSM_BIT_AC_PRESENT);
 		break;

 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
 		regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
 		if (regval < 0)
 			return regval;

 		if ((regval & SBSM_MASK_CHARGE_BAT) == 0) {
 			val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
 			return 0;
 		}
 		val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

 		if (data->is_ltc1760) {
 			/* charge mode fast if turbo is active */
 			regval = sbsm_read_word(data->client, SBSM_CMD_LTC);
 			if (regval < 0)
 				return regval;
 			else if (regval & SBSM_BIT_TURBO)
 				val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
 		}
 		break;

 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int sbsm_prop_is_writeable(struct power_supply *psy,
 				  enum power_supply_property psp)
 {
 	struct sbsm_data *data = power_supply_get_drvdata(psy);

 	return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760;
 }

 static int sbsm_set_property(struct power_supply *psy,
 			     enum power_supply_property psp,
 			     const union power_supply_propval *val)
 {
 	struct sbsm_data *data = power_supply_get_drvdata(psy);
 	int ret = -EINVAL;
 	u16 regval;

 	switch (psp) {
 	case POWER_SUPPLY_PROP_CHARGE_TYPE:
 		/* write 1 to TURBO if type fast is given */
 		if (!data->is_ltc1760)
 			break;
 		regval = val->intval ==
 			 POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0;
 		ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval);
 		break;

 	default:
 		break;
 	}

 	return ret;
 }

 /*
  * Switch to battery
  * Parameter chan is directly the content of SMB_BAT* nibble
  */
 static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
 {
 	struct sbsm_data *data = i2c_mux_priv(muxc);
 	struct device *dev = &data->client->dev;
 	int ret = 0;
 	u16 reg;

 	if (data->cur_chan == chan)
 		return ret;

 	/* chan goes from 1 ... 4 */
 	reg = 1 << BIT(SBSM_SMB_BAT_OFFSET + chan);
 	ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
 	if (ret)
 		dev_err(dev, "Failed to select channel %i\n", chan);
 	else
 		data->cur_chan = chan;

 	return ret;
 }

 static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off)
 {
 	struct sbsm_data *data = gpiochip_get_data(gc);
 	int ret;

 	ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
 	if (ret < 0)
 		return ret;

 	return ret & BIT(off);
 }

 /*
  * This needs to be defined or the GPIO lib fails to register the pin.
  * But the 'gpio' is always an input.
  */
 static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off)
 {
 	return 0;
 }

 static int sbsm_do_alert(struct device *dev, void *d)
 {
 	struct i2c_client *client = i2c_verify_client(dev);
 	struct i2c_driver *driver;

 	if (!client || client->addr != 0x0b)
 		return 0;

 	device_lock(dev);
 	if (client->dev.driver) {
 		driver = to_i2c_driver(client->dev.driver);
 		if (driver->alert)
 			driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0);
 		else
 			dev_warn(&client->dev, "no driver alert()!\n");
 	} else {
 		dev_dbg(&client->dev, "alert with no driver\n");
 	}
 	device_unlock(dev);

 	return -EBUSY;
 }

 static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
 		       unsigned int d)
 {
 	struct sbsm_data *sbsm = i2c_get_clientdata(client);

 	int ret, i, irq_bat = 0, state = 0;

 	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
 	if (ret >= 0) {
 		irq_bat = ret ^ sbsm->last_state;
 		sbsm->last_state = ret;
 		state = ret;
 	}

 	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT);
 	if ((ret >= 0) &&
 	    ((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) {
 		irq_bat |= sbsm->supported_bats & state;
 		power_supply_changed(sbsm->psy);
 	}
 	sbsm->last_state_cont = ret;

 	for (i = 0; i < SBSM_MAX_BATS; i++) {
 		if (irq_bat & BIT(i)) {
 			device_for_each_child(&sbsm->muxc->adapter[i]->dev,
 					      NULL, sbsm_do_alert);
 		}
 	}
 }

 static int sbsm_gpio_setup(struct sbsm_data *data)
 {
 	struct gpio_chip *gc = &data->chip;
 	struct i2c_client *client = data->client;
 	struct device *dev = &client->dev;
 	int ret;

 	if (!device_property_present(dev, "gpio-controller"))
 		return 0;

 	ret  = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE);
 	if (ret < 0)
 		return ret;
 	data->last_state = ret;

 	ret  = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT);
 	if (ret < 0)
 		return ret;
 	data->last_state_cont = ret;

 	gc->get = sbsm_gpio_get_value;
 	gc->direction_input  = sbsm_gpio_direction_input;
 	gc->can_sleep = true;
 	gc->base = -1;
 	gc->ngpio = SBSM_MAX_BATS;
 	gc->label = client->name;
 	gc->parent = dev;
 	gc->owner = THIS_MODULE;

 	ret = devm_gpiochip_add_data(dev, gc, data);
 	if (ret) {
 		dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret);
 		return ret;
 	}

 	return ret;
 }

 static const struct power_supply_desc sbsm_default_psy_desc = {
 	.type = POWER_SUPPLY_TYPE_MAINS,
 	.properties = sbsm_props,
 	.num_properties = ARRAY_SIZE(sbsm_props),
 	.get_property = &sbsm_get_property,
 	.set_property = &sbsm_set_property,
 	.property_is_writeable = &sbsm_prop_is_writeable,
 };

 static int sbsm_probe(struct i2c_client *client,
 		      const struct i2c_device_id *id)
 {
 	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
 	struct sbsm_data *data;
 	struct device *dev = &client->dev;
 	struct power_supply_desc *psy_desc;
 	struct power_supply_config psy_cfg = {};
 	int ret = 0, i;

 	/* Device listens only at address 0x0a */
 	if (client->addr != 0x0a)
 		return -EINVAL;

 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
 		return -EPFNOSUPPORT;

 	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
 	if (!data)
 		return -ENOMEM;

 	i2c_set_clientdata(client, data);

 	data->client = client;
 	data->is_ltc1760 = !!strstr(id->name, "ltc1760");

 	ret  = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
 	if (ret < 0)
 		return ret;
 	data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED;
 	data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
 				   I2C_MUX_LOCKED, &sbsm_select, NULL);
 	if (!data->muxc) {
 		dev_err(dev, "failed to alloc i2c mux\n");
 		ret = -ENOMEM;
 		goto err_mux_alloc;
 	}
 	data->muxc->priv = data;

 	/* register muxed i2c channels. One for each supported battery */
 	for (i = 0; i < SBSM_MAX_BATS; ++i) {
 		if (data->supported_bats & BIT(i)) {
 			ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
 			if (ret)
 				break;
 		}
 	}
 	if (ret) {
 		dev_err(dev, "failed to register i2c mux channel %d\n", i + 1);
 		goto err_mux_register;
 	}

 	psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc,
 				sizeof(struct power_supply_desc),
 				GFP_KERNEL);
 	if (!psy_desc) {
 		ret = -ENOMEM;
 		goto err_psy;
 	}

 	psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s",
 					dev_name(&client->dev));
 	if (!psy_desc->name) {
 		ret = -ENOMEM;
 		goto err_psy;
 	}
 	ret = sbsm_gpio_setup(data);
 	if (ret < 0)
 		goto err_psy;

 	psy_cfg.drv_data = data;
 	psy_cfg.of_node = dev->of_node;
 	data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
 	if (IS_ERR(data->psy)) {
 		ret = PTR_ERR(data->psy);
 		dev_err(dev, "failed to register power supply %s\n",
 			psy_desc->name);
 		goto err_psy;
 	}

 	return 0;

 err_psy:
 err_mux_register:
 	i2c_mux_del_adapters(data->muxc);

 err_mux_alloc:
 	return ret;
 }

 static int sbsm_remove(struct i2c_client *client)
 {
 	struct sbsm_data *data = i2c_get_clientdata(client);

 	i2c_mux_del_adapters(data->muxc);
 	return 0;
 }

 static const struct i2c_device_id sbsm_ids[] = {
 	{ "sbs-manager", 0 },
 	{ "ltc1760",     0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, sbsm_ids);

 #ifdef CONFIG_OF
 static const struct of_device_id sbsm_dt_ids[] = {
 	{ .compatible = "sbs,sbs-manager" },
 	{ .compatible = "lltc,ltc1760" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, sbsm_dt_ids);
 #endif

 static struct i2c_driver sbsm_driver = {
 	.driver = {
 		.name = "sbsm",
 		.of_match_table = of_match_ptr(sbsm_dt_ids),
 	},
 	.probe		= sbsm_probe,
 	.remove		= sbsm_remove,
 	.alert		= sbsm_alert,
 	.id_table	= sbsm_ids
 };
 module_i2c_driver(sbsm_driver);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>");
 MODULE_DESCRIPTION("SBSM Smart Battery System Manager");
	/*
	* Driver for SBS compliant Smart Battery System Managers
	*
	* The device communicates via i2c at address 0x0a and multiplexes access to up
	* to four smart batteries at address 0x0b.
	*
	* Via sysfs interface the online state and charge type are presented.
	*
	* Datasheet SBSM: http://sbs-forum.org/specs/sbsm100b.pdf
	* Datasheet LTC1760: http://cds.linear.com/docs/en/datasheet/1760fb.pdf
	*
	* Karl-Heinz Schneider <karl-heinz@schneider-inet.de>
	*
	* This program 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.
	*/

	#include <linux/gpio.h>
	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/i2c-mux.h>
	#include <linux/power_supply.h>
	#include <linux/property.h>

	#define SBSM_MAX_BATS 4
	#define SBSM_RETRY_CNT 3

	/* registers addresses */
	#define SBSM_CMD_BATSYSSTATE 0x01
	#define SBSM_CMD_BATSYSSTATECONT 0x02
	#define SBSM_CMD_BATSYSINFO 0x04
	#define SBSM_CMD_LTC 0x3c

	#define SBSM_MASK_BAT_SUPPORTED GENMASK(3, 0)
	#define SBSM_MASK_CHARGE_BAT GENMASK(7, 4)
	#define SBSM_BIT_AC_PRESENT BIT(0)
	#define SBSM_BIT_TURBO BIT(7)

	#define SBSM_SMB_BAT_OFFSET 11
	struct sbsm_data {
	struct i2c_client *client;
	struct i2c_mux_core *muxc;

	struct power_supply *psy;

	u8 cur_chan; /* currently selected channel */
	struct gpio_chip chip;
	bool is_ltc1760; /* special capabilities */

	unsigned int supported_bats;
	unsigned int last_state;
	unsigned int last_state_cont;
	};

	static enum power_supply_property sbsm_props[] = {
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_CHARGE_TYPE,
	};

	static int sbsm_read_word(struct i2c_client *client, u8 address)
	{
	int reg, retries;

	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
	reg = i2c_smbus_read_word_data(client, address);
	if (reg >= 0)
	break;
	}

	if (reg < 0) {
	dev_err(&client->dev, "failed to read register 0x%02x\n",
	address);
	}

	return reg;
	}

	static int sbsm_write_word(struct i2c_client *client, u8 address, u16 word)
	{
	int ret, retries;

	for (retries = SBSM_RETRY_CNT; retries > 0; retries--) {
	ret = i2c_smbus_write_word_data(client, address, word);
	if (ret >= 0)
	break;
	}
	if (ret < 0)
	dev_err(&client->dev, "failed to write to register 0x%02x\n",
	address);

	return ret;
	}

	static int sbsm_get_property(struct power_supply *psy,
	enum power_supply_property psp,
	union power_supply_propval *val)
	{
	struct sbsm_data *data = power_supply_get_drvdata(psy);
	int regval = 0;

	switch (psp) {
	case POWER_SUPPLY_PROP_ONLINE:
	regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATECONT);
	if (regval < 0)
	return regval;
	val->intval = !!(regval & SBSM_BIT_AC_PRESENT);
	break;

	case POWER_SUPPLY_PROP_CHARGE_TYPE:
	regval = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
	if (regval < 0)
	return regval;

	if ((regval & SBSM_MASK_CHARGE_BAT) == 0) {
	val->intval = POWER_SUPPLY_CHARGE_TYPE_NONE;
	return 0;
	}
	val->intval = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;

	if (data->is_ltc1760) {
	/* charge mode fast if turbo is active */
	regval = sbsm_read_word(data->client, SBSM_CMD_LTC);
	if (regval < 0)
	return regval;
	else if (regval & SBSM_BIT_TURBO)
	val->intval = POWER_SUPPLY_CHARGE_TYPE_FAST;
	}
	break;

	default:
	return -EINVAL;
	}

	return 0;
	}

	static int sbsm_prop_is_writeable(struct power_supply *psy,
	enum power_supply_property psp)
	{
	struct sbsm_data *data = power_supply_get_drvdata(psy);

	return (psp == POWER_SUPPLY_PROP_CHARGE_TYPE) && data->is_ltc1760;
	}

	static int sbsm_set_property(struct power_supply *psy,
	enum power_supply_property psp,
	const union power_supply_propval *val)
	{
	struct sbsm_data *data = power_supply_get_drvdata(psy);
	int ret = -EINVAL;
	u16 regval;

	switch (psp) {
	case POWER_SUPPLY_PROP_CHARGE_TYPE:
	/* write 1 to TURBO if type fast is given */
	if (!data->is_ltc1760)
	break;
	regval = val->intval ==
	POWER_SUPPLY_CHARGE_TYPE_FAST ? SBSM_BIT_TURBO : 0;
	ret = sbsm_write_word(data->client, SBSM_CMD_LTC, regval);
	break;

	default:
	break;
	}

	return ret;
	}

	/*
	* Switch to battery
	* Parameter chan is directly the content of SMB_BAT* nibble
	*/
	static int sbsm_select(struct i2c_mux_core *muxc, u32 chan)
	{
	struct sbsm_data *data = i2c_mux_priv(muxc);
	struct device *dev = &data->client->dev;
	int ret = 0;
	u16 reg;

	if (data->cur_chan == chan)
	return ret;

	/* chan goes from 1 ... 4 */
	reg = 1 << BIT(SBSM_SMB_BAT_OFFSET + chan);
	ret = sbsm_write_word(data->client, SBSM_CMD_BATSYSSTATE, reg);
	if (ret)
	dev_err(dev, "Failed to select channel %i\n", chan);
	else
	data->cur_chan = chan;

	return ret;
	}

	static int sbsm_gpio_get_value(struct gpio_chip *gc, unsigned int off)
	{
	struct sbsm_data *data = gpiochip_get_data(gc);
	int ret;

	ret = sbsm_read_word(data->client, SBSM_CMD_BATSYSSTATE);
	if (ret < 0)
	return ret;

	return ret & BIT(off);
	}

	/*
	* This needs to be defined or the GPIO lib fails to register the pin.
	* But the 'gpio' is always an input.
	*/
	static int sbsm_gpio_direction_input(struct gpio_chip *gc, unsigned int off)
	{
	return 0;
	}

	static int sbsm_do_alert(struct device dev, void d)
	{
	struct i2c_client *client = i2c_verify_client(dev);
	struct i2c_driver *driver;

	if (!client \|\| client->addr != 0x0b)
	return 0;

	device_lock(dev);
	if (client->dev.driver) {
	driver = to_i2c_driver(client->dev.driver);
	if (driver->alert)
	driver->alert(client, I2C_PROTOCOL_SMBUS_ALERT, 0);
	else
	dev_warn(&client->dev, "no driver alert()!\n");
	} else {
	dev_dbg(&client->dev, "alert with no driver\n");
	}
	device_unlock(dev);

	return -EBUSY;
	}

	static void sbsm_alert(struct i2c_client *client, enum i2c_alert_protocol prot,
	unsigned int d)
	{
	struct sbsm_data *sbsm = i2c_get_clientdata(client);

	int ret, i, irq_bat = 0, state = 0;

	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATE);
	if (ret >= 0) {
	irq_bat = ret ^ sbsm->last_state;
	sbsm->last_state = ret;
	state = ret;
	}

	ret = sbsm_read_word(sbsm->client, SBSM_CMD_BATSYSSTATECONT);
	if ((ret >= 0) &&
	((ret ^ sbsm->last_state_cont) & SBSM_BIT_AC_PRESENT)) {
	irq_bat \|= sbsm->supported_bats & state;
	power_supply_changed(sbsm->psy);
	}
	sbsm->last_state_cont = ret;

	for (i = 0; i < SBSM_MAX_BATS; i++) {
	if (irq_bat & BIT(i)) {
	device_for_each_child(&sbsm->muxc->adapter[i]->dev,
	NULL, sbsm_do_alert);
	}
	}
	}

	static int sbsm_gpio_setup(struct sbsm_data *data)
	{
	struct gpio_chip *gc = &data->chip;
	struct i2c_client *client = data->client;
	struct device *dev = &client->dev;
	int ret;

	if (!device_property_present(dev, "gpio-controller"))
	return 0;

	ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATE);
	if (ret < 0)
	return ret;
	data->last_state = ret;

	ret = sbsm_read_word(client, SBSM_CMD_BATSYSSTATECONT);
	if (ret < 0)
	return ret;
	data->last_state_cont = ret;

	gc->get = sbsm_gpio_get_value;
	gc->direction_input = sbsm_gpio_direction_input;
	gc->can_sleep = true;
	gc->base = -1;
	gc->ngpio = SBSM_MAX_BATS;
	gc->label = client->name;
	gc->parent = dev;
	gc->owner = THIS_MODULE;

	ret = devm_gpiochip_add_data(dev, gc, data);
	if (ret) {
	dev_err(dev, "devm_gpiochip_add_data failed: %d\n", ret);
	return ret;
	}

	return ret;
	}

	static const struct power_supply_desc sbsm_default_psy_desc = {
	.type = POWER_SUPPLY_TYPE_MAINS,
	.properties = sbsm_props,
	.num_properties = ARRAY_SIZE(sbsm_props),
	.get_property = &sbsm_get_property,
	.set_property = &sbsm_set_property,
	.property_is_writeable = &sbsm_prop_is_writeable,
	};

	static int sbsm_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct sbsm_data *data;
	struct device *dev = &client->dev;
	struct power_supply_desc *psy_desc;
	struct power_supply_config psy_cfg = {};
	int ret = 0, i;

	/* Device listens only at address 0x0a */
	if (client->addr != 0x0a)
	return -EINVAL;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
	return -EPFNOSUPPORT;

	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
	if (!data)
	return -ENOMEM;

	i2c_set_clientdata(client, data);

	data->client = client;
	data->is_ltc1760 = !!strstr(id->name, "ltc1760");

	ret = sbsm_read_word(client, SBSM_CMD_BATSYSINFO);
	if (ret < 0)
	return ret;
	data->supported_bats = ret & SBSM_MASK_BAT_SUPPORTED;
	data->muxc = i2c_mux_alloc(adapter, dev, SBSM_MAX_BATS, 0,
	I2C_MUX_LOCKED, &sbsm_select, NULL);
	if (!data->muxc) {
	dev_err(dev, "failed to alloc i2c mux\n");
	ret = -ENOMEM;
	goto err_mux_alloc;
	}
	data->muxc->priv = data;

	/* register muxed i2c channels. One for each supported battery */
	for (i = 0; i < SBSM_MAX_BATS; ++i) {
	if (data->supported_bats & BIT(i)) {
	ret = i2c_mux_add_adapter(data->muxc, 0, i + 1, 0);
	if (ret)
	break;
	}
	}
	if (ret) {
	dev_err(dev, "failed to register i2c mux channel %d\n", i + 1);
	goto err_mux_register;
	}

	psy_desc = devm_kmemdup(dev, &sbsm_default_psy_desc,
	sizeof(struct power_supply_desc),
	GFP_KERNEL);
	if (!psy_desc) {
	ret = -ENOMEM;
	goto err_psy;
	}

	psy_desc->name = devm_kasprintf(dev, GFP_KERNEL, "sbsm-%s",
	dev_name(&client->dev));
	if (!psy_desc->name) {
	ret = -ENOMEM;
	goto err_psy;
	}
	ret = sbsm_gpio_setup(data);
	if (ret < 0)
	goto err_psy;

	psy_cfg.drv_data = data;
	psy_cfg.of_node = dev->of_node;
	data->psy = devm_power_supply_register(dev, psy_desc, &psy_cfg);
	if (IS_ERR(data->psy)) {
	ret = PTR_ERR(data->psy);
	dev_err(dev, "failed to register power supply %s\n",
	psy_desc->name);
	goto err_psy;
	}

	return 0;

	err_psy:
	err_mux_register:
	i2c_mux_del_adapters(data->muxc);

	err_mux_alloc:
	return ret;
	}

	static int sbsm_remove(struct i2c_client *client)
	{
	struct sbsm_data *data = i2c_get_clientdata(client);

	i2c_mux_del_adapters(data->muxc);
	return 0;
	}

	static const struct i2c_device_id sbsm_ids[] = {
	{ "sbs-manager", 0 },
	{ "ltc1760", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, sbsm_ids);

	#ifdef CONFIG_OF
	static const struct of_device_id sbsm_dt_ids[] = {
	{ .compatible = "sbs,sbs-manager" },
	{ .compatible = "lltc,ltc1760" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, sbsm_dt_ids);
	#endif

	static struct i2c_driver sbsm_driver = {
	.driver = {
	.name = "sbsm",
	.of_match_table = of_match_ptr(sbsm_dt_ids),
	},
	.probe = sbsm_probe,
	.remove = sbsm_remove,
	.alert = sbsm_alert,
	.id_table = sbsm_ids
	};
	module_i2c_driver(sbsm_driver);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Karl-Heinz Schneider <karl-heinz@schneider-inet.de>");
	MODULE_DESCRIPTION("SBSM Smart Battery System Manager");