[v2,2/2] power: supply: Add Spreadtrum SC2731 charger support

Commit Message

(Exiting) Baolin Wang Sept. 3, 2018, 8:55 a.m. UTC

This patch adds the SC2731 PMIC switch charger support.

Signed-off-by: Baolin Wang <[e-mail]>
---
Changes from v1:
 - Remove some redundant head files.
 - Add one mutex to make sure getting the charger status is correct.
 - Fix some coding style issues.
 - Use standard DT properties.
---
 drivers/power/supply/Kconfig          |    7 +
 drivers/power/supply/Makefile         |    1 +
 drivers/power/supply/sc2731_charger.c |  503 +++++++++++++++++++++++++++++++++
 3 files changed, 511 insertions(+)
 create mode 100644 drivers/power/supply/sc2731_charger.c

Comments

Krzysztof Kozlowski Sept. 3, 2018, 10:20 a.m. UTC | #1

On Mon, 3 Sep 2018 at 10:56, Baolin Wang <[e-mail]> wrote:
>
> This patch adds the SC2731 PMIC switch charger support.
>
> Signed-off-by: Baolin Wang <[e-mail]>
> ---
> Changes from v1:
>  - Remove some redundant head files.
>  - Add one mutex to make sure getting the charger status is correct.
>  - Fix some coding style issues.
>  - Use standard DT properties.
> ---
>  drivers/power/supply/Kconfig          |    7 +
>  drivers/power/supply/Makefile         |    1 +
>  drivers/power/supply/sc2731_charger.c |  503 +++++++++++++++++++++++++++++++++
>  3 files changed, 511 insertions(+)
>  create mode 100644 drivers/power/supply/sc2731_charger.c

Reviewed-by: Krzysztof Kozlowski <[e-mail]>

Best regards,
Krzysztof

Sebastian Reichel Sept. 16, 2018, 10:17 a.m. UTC | #2

Hi Baolin,

On Mon, Sep 03, 2018 at 04:55:46PM +0800, Baolin Wang wrote:
> This patch adds the SC2731 PMIC switch charger support.
> 
> Signed-off-by: Baolin Wang <[e-mail]>
> ---

The power-supply sysfs files uses uA instead of mA, otherwise the
driver and the binding looks fine to me.

-- Sebastian

> Changes from v1:
>  - Remove some redundant head files.
>  - Add one mutex to make sure getting the charger status is correct.
>  - Fix some coding style issues.
>  - Use standard DT properties.
> ---
>  drivers/power/supply/Kconfig          |    7 +
>  drivers/power/supply/Makefile         |    1 +
>  drivers/power/supply/sc2731_charger.c |  503 +++++++++++++++++++++++++++++++++
>  3 files changed, 511 insertions(+)
>  create mode 100644 drivers/power/supply/sc2731_charger.c
> 
> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
> index ff6dab0..f27cf07 100644
> --- a/drivers/power/supply/Kconfig
> +++ b/drivers/power/supply/Kconfig
> @@ -645,4 +645,11 @@ config CHARGER_CROS_USBPD
>  	  what is connected to USB PD ports from the EC and converts
>  	  that into power_supply properties.
>  
> +config CHARGER_SC2731
> +	tristate "Spreadtrum SC2731 charger driver"
> +	depends on MFD_SC27XX_PMIC || COMPILE_TEST
> +	help
> +	 Say Y here to enable support for battery charging with SC2731
> +	 PMIC chips.
> +
>  endif # POWER_SUPPLY
> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
> index a26b402..767105b 100644
> --- a/drivers/power/supply/Makefile
> +++ b/drivers/power/supply/Makefile
> @@ -85,3 +85,4 @@ obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
>  obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
>  obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
>  obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
> +obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
> diff --git a/drivers/power/supply/sc2731_charger.c b/drivers/power/supply/sc2731_charger.c
> new file mode 100644
> index 0000000..c92e5fc
> --- /dev/null
> +++ b/drivers/power/supply/sc2731_charger.c
> @@ -0,0 +1,503 @@
> +// SPDX-License-Identifier: GPL-2.0
> +// Copyright (C) 2018 Spreadtrum Communications Inc.
> +
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/usb/phy.h>
> +#include <linux/regmap.h>
> +#include <linux/notifier.h>
> +#include <linux/of.h>
> +
> +/* PMIC global registers definition */
> +#define SC2731_CHARGE_STATUS		0xedc
> +#define SC2731_CHARGE_FULL		BIT(4)
> +#define SC2731_MODULE_EN1		0xc0c
> +#define SC2731_CHARGE_EN		BIT(5)
> +
> +/* SC2731 switch charger registers definition */
> +#define SC2731_CHG_CFG0			0x0
> +#define SC2731_CHG_CFG1			0x4
> +#define SC2731_CHG_CFG2			0x8
> +#define SC2731_CHG_CFG3			0xc
> +#define SC2731_CHG_CFG4			0x10
> +#define SC2731_CHG_CFG5			0x28
> +
> +/* SC2731_CHG_CFG0 register definition */
> +#define SC2731_PRECHG_RNG_SHIFT		11
> +#define SC2731_PRECHG_RNG_MASK		GENMASK(12, 11)
> +
> +#define SC2731_TERMINATION_VOL_MASK	GENMASK(2, 1)
> +#define SC2731_TERMINATION_VOL_SHIFT	1
> +#define SC2731_TERMINATION_VOL_CAL_MASK	GENMASK(8, 3)
> +#define SC2731_TERMINATION_VOL_CAL_SHIFT	3
> +#define SC2731_TERMINATION_CUR_MASK	GENMASK(2, 0)
> +
> +#define SC2731_CC_EN			BIT(13)
> +#define SC2731_CHARGER_PD		BIT(0)
> +
> +/* SC2731_CHG_CFG1 register definition */
> +#define SC2731_CUR_MASK			GENMASK(5, 0)
> +
> +/* SC2731_CHG_CFG5 register definition */
> +#define SC2731_CUR_LIMIT_SHIFT		8
> +#define SC2731_CUR_LIMIT_MASK		GENMASK(9, 8)
> +
> +/* Default current definition (unit is mA) */
> +#define SC2731_CURRENT_LIMIT_100	100
> +#define SC2731_CURRENT_LIMIT_500	500
> +#define SC2731_CURRENT_LIMIT_900	900
> +#define SC2731_CURRENT_LIMIT_2000	2000
> +#define SC2731_CURRENT_PRECHG		450
> +#define SC2731_CURRENT_STEP		50
> +
> +struct sc2731_charger_info {
> +	struct device *dev;
> +	struct regmap *regmap;
> +	struct usb_phy *usb_phy;
> +	struct notifier_block usb_notify;
> +	struct power_supply *psy_usb;
> +	struct mutex lock;
> +	bool charging;
> +	u32 base;
> +};
> +
> +static void sc2731_charger_stop_charge(struct sc2731_charger_info *info)
> +{
> +	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +			   SC2731_CC_EN, 0);
> +
> +	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +			   SC2731_CHARGER_PD, SC2731_CHARGER_PD);
> +}
> +
> +static int sc2731_charger_start_charge(struct sc2731_charger_info *info)
> +{
> +	int ret;
> +
> +	/* Enable charger constant current mode */
> +	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +				 SC2731_CC_EN, SC2731_CC_EN);
> +	if (ret)
> +		return ret;
> +
> +	/* Start charging */
> +	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +				  SC2731_CHARGER_PD, 0);
> +}
> +
> +static int sc2731_charger_set_current_limit(struct sc2731_charger_info *info,
> +					    u32 limit)
> +{
> +	u32 val;
> +
> +	if (limit <= SC2731_CURRENT_LIMIT_100)
> +		val = 0;
> +	else if (limit <= SC2731_CURRENT_LIMIT_500)
> +		val = 3;
> +	else if (limit <= SC2731_CURRENT_LIMIT_900)
> +		val = 2;
> +	else
> +		val = 1;
> +
> +	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG5,
> +				  SC2731_CUR_LIMIT_MASK,
> +				  val << SC2731_CUR_LIMIT_SHIFT);
> +}
> +
> +static int sc2731_charger_set_current(struct sc2731_charger_info *info, u32 cur)
> +{
> +	u32 val;
> +	int ret;
> +
> +	if (cur > SC2731_CURRENT_LIMIT_2000)
> +		cur = SC2731_CURRENT_LIMIT_2000;
> +	else if (cur < SC2731_CURRENT_PRECHG)
> +		cur = SC2731_CURRENT_PRECHG;
> +
> +	/* Calculate the step value, each step is 50 mA */
> +	val = (cur - SC2731_CURRENT_PRECHG) / SC2731_CURRENT_STEP;
> +
> +	/* Set pre-charge current as 450 mA */
> +	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +				 SC2731_PRECHG_RNG_MASK,
> +				 0x3 << SC2731_PRECHG_RNG_SHIFT);
> +	if (ret)
> +		return ret;
> +
> +	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG1,
> +				  SC2731_CUR_MASK, val);
> +}
> +
> +static int sc2731_charger_get_status(struct sc2731_charger_info *info)
> +{
> +	u32 val;
> +	int ret;
> +
> +	ret = regmap_read(info->regmap, SC2731_CHARGE_STATUS, &val);
> +	if (ret)
> +		return ret;
> +
> +	if (val & SC2731_CHARGE_FULL)
> +		return POWER_SUPPLY_STATUS_FULL;
> +
> +	return POWER_SUPPLY_STATUS_CHARGING;
> +}
> +
> +static int sc2731_charger_get_current(struct sc2731_charger_info *info,
> +				      u32 *cur)
> +{
> +	int ret;
> +	u32 val;
> +
> +	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG1, &val);
> +	if (ret)
> +		return ret;
> +
> +	val &= SC2731_CUR_MASK;
> +	*cur = val * SC2731_CURRENT_STEP + SC2731_CURRENT_PRECHG;
> +
> +	return 0;
> +}
> +
> +static int sc2731_charger_get_current_limit(struct sc2731_charger_info *info,
> +					    u32 *cur)
> +{
> +	int ret;
> +	u32 val;
> +
> +	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG5, &val);
> +	if (ret)
> +		return ret;
> +
> +	val = (val & SC2731_CUR_LIMIT_MASK) >> SC2731_CUR_LIMIT_SHIFT;
> +
> +	switch (val) {
> +	case 0:
> +		*cur = SC2731_CURRENT_LIMIT_100;
> +		break;
> +
> +	case 1:
> +		*cur = SC2731_CURRENT_LIMIT_2000;
> +		break;
> +
> +	case 2:
> +		*cur = SC2731_CURRENT_LIMIT_900;
> +		break;
> +
> +	case 3:
> +		*cur = SC2731_CURRENT_LIMIT_500;
> +		break;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int
> +sc2731_charger_usb_set_property(struct power_supply *psy,
> +				enum power_supply_property psp,
> +				const union power_supply_propval *val)
> +{
> +	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
> +	int ret;
> +
> +	mutex_lock(&info->lock);
> +
> +	if (!info->charging) {
> +		mutex_unlock(&info->lock);
> +		return -ENODEV;
> +	}
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +		ret = sc2731_charger_set_current(info, val->intval);
> +		if (ret < 0)
> +			dev_err(info->dev, "set charge current failed\n");
> +		break;

This gets uA as input (instead of mA).

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
> +		ret = sc2731_charger_set_current_limit(info, val->intval);
> +		if (ret < 0)
> +			dev_err(info->dev, "set input current limit failed\n");
> +		break;

This gets uA as input (instead of mA).

> +
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	mutex_unlock(&info->lock);
> +	return ret;
> +}
> +
> +static int sc2731_charger_usb_get_property(struct power_supply *psy,
> +					   enum power_supply_property psp,
> +					   union power_supply_propval *val)
> +{
> +	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
> +	int ret = 0;
> +	u32 cur;
> +
> +	mutex_lock(&info->lock);
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_STATUS:
> +		if (info->charging)
> +			val->intval = sc2731_charger_get_status(info);
> +		else
> +			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +		break;
> +
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +		if (!info->charging) {
> +			val->intval = 0;
> +		} else {
> +			ret = sc2731_charger_get_current(info, &cur);
> +			if (ret)
> +				goto out;
> +
> +			val->intval = cur;
> +		}
> +		break;

This should always report uA (instead of mA).

> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
> +		if (!info->charging) {
> +			val->intval = 0;
> +		} else {
> +			ret = sc2731_charger_get_current_limit(info, &cur);
> +			if (ret)
> +				goto out;
> +
> +			val->intval = cur;
> +		}
> +		break;

This should always report uA (instead of mA).

> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +out:
> +	mutex_unlock(&info->lock);
> +	return ret;
> +}
> +
> +static int sc2731_charger_property_is_writeable(struct power_supply *psy,
> +						enum power_supply_property psp)
> +{
> +	int ret;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
> +	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
> +		ret = 1;
> +		break;
> +
> +	default:
> +		ret = 0;
> +	}
> +
> +	return ret;
> +}
> +
> +static enum power_supply_property sc2731_usb_props[] = {
> +	POWER_SUPPLY_PROP_STATUS,
> +	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
> +	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
> +};
> +
> +static const struct power_supply_desc sc2731_charger_desc = {
> +	.name			= "sc2731_charger",
> +	.type			= POWER_SUPPLY_TYPE_USB,
> +	.properties		= sc2731_usb_props,
> +	.num_properties		= ARRAY_SIZE(sc2731_usb_props),
> +	.get_property		= sc2731_charger_usb_get_property,
> +	.set_property		= sc2731_charger_usb_set_property,
> +	.property_is_writeable	= sc2731_charger_property_is_writeable,
> +};
> +
> +static int sc2731_charger_usb_change(struct notifier_block *nb,
> +				     unsigned long limit, void *data)
> +{
> +	struct sc2731_charger_info *info =
> +		container_of(nb, struct sc2731_charger_info, usb_notify);
> +	int ret = 0;
> +
> +	mutex_lock(&info->lock);
> +
> +	if (limit > 0) {
> +		/* set current limitation and start to charge */
> +		ret = sc2731_charger_set_current_limit(info, limit);
> +		if (ret)
> +			goto out;
> +
> +		ret = sc2731_charger_set_current(info, limit);
> +		if (ret)
> +			goto out;
> +
> +		ret = sc2731_charger_start_charge(info);
> +		if (ret)
> +			goto out;
> +
> +		info->charging = true;
> +	} else {
> +		/* Stop charging */
> +		info->charging = false;
> +		sc2731_charger_stop_charge(info);
> +	}
> +
> +out:
> +	mutex_unlock(&info->lock);
> +	return ret;
> +}
> +
> +static int sc2731_charger_hw_init(struct sc2731_charger_info *info)
> +{
> +	struct power_supply_battery_info bat_info = { };
> +	u32 term_currrent, term_voltage, cur_val, vol_val;
> +	int ret;
> +
> +	/* Enable charger module */
> +	ret = regmap_update_bits(info->regmap, SC2731_MODULE_EN1,
> +				 SC2731_CHARGE_EN, SC2731_CHARGE_EN);
> +	if (ret)
> +		return ret;
> +
> +	ret = power_supply_get_battery_info(info->psy_usb, &bat_info);
> +	if (ret) {
> +		dev_warn(info->dev, "no battery information is supplied\n");
> +
> +		/*
> +		 * If no battery information is supplied, we should set
> +		 * default charge termination current to 120 mA, and default
> +		 * charge termination voltage to 4.35V.
> +		 */
> +		cur_val = 0x2;
> +		vol_val = 0x1;
> +	} else {
> +		term_currrent = bat_info.charge_term_current_ua / 1000;
> +
> +		if (term_currrent <= 90)
> +			cur_val = 0;
> +		else if (term_currrent >= 265)
> +			cur_val = 0x7;
> +		else
> +			cur_val = ((term_currrent - 90) / 25) + 1;
> +
> +		term_voltage = bat_info.constant_charge_voltage_max_uv / 1000;
> +
> +		if (term_voltage > 4500)
> +			term_voltage = 4500;
> +
> +		if (term_voltage > 4200)
> +			vol_val = (term_voltage - 4200) / 100;
> +		else
> +			vol_val = 0;
> +	}
> +
> +	/* Set charge termination current */
> +	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG2,
> +				 SC2731_TERMINATION_CUR_MASK, cur_val);
> +	if (ret)
> +		goto error;
> +
> +	/* Set charge termination voltage */
> +	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
> +				 SC2731_TERMINATION_VOL_MASK |
> +				 SC2731_TERMINATION_VOL_CAL_MASK,
> +				 (vol_val << SC2731_TERMINATION_VOL_SHIFT) |
> +				 (0x6 << SC2731_TERMINATION_VOL_CAL_SHIFT));
> +	if (ret)
> +		goto error;
> +
> +	return 0;
> +
> +error:
> +	regmap_update_bits(info->regmap, SC2731_MODULE_EN1, SC2731_CHARGE_EN, 0);
> +	return ret;
> +}
> +
> +static int sc2731_charger_probe(struct platform_device *pdev)
> +{
> +	struct device_node *np = pdev->dev.of_node;
> +	struct sc2731_charger_info *info;
> +	struct power_supply_config charger_cfg = { };
> +	int ret;
> +
> +	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
> +	if (!info)
> +		return -ENOMEM;
> +
> +	mutex_init(&info->lock);
> +	info->dev = &pdev->dev;
> +
> +	info->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> +	if (!info->regmap) {
> +		dev_err(&pdev->dev, "failed to get charger regmap\n");
> +		return -ENODEV;
> +	}
> +
> +	ret = of_property_read_u32(np, "reg", &info->base);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to get register address\n");
> +		return -ENODEV;
> +	}
> +
> +	charger_cfg.drv_data = info;
> +	charger_cfg.of_node = np;
> +	info->psy_usb = devm_power_supply_register(&pdev->dev,
> +						   &sc2731_charger_desc,
> +						   &charger_cfg);
> +	if (IS_ERR(info->psy_usb)) {
> +		dev_err(&pdev->dev, "failed to register power supply\n");
> +		return PTR_ERR(info->psy_usb);
> +	}
> +
> +	ret = sc2731_charger_hw_init(info);
> +	if (ret)
> +		return ret;
> +
> +	info->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "phys", 0);
> +	if (IS_ERR(info->usb_phy)) {
> +		dev_err(&pdev->dev, "failed to find USB phy\n");
> +		return PTR_ERR(info->usb_phy);
> +	}
> +
> +	info->usb_notify.notifier_call = sc2731_charger_usb_change;
> +	ret = usb_register_notifier(info->usb_phy, &info->usb_notify);
> +	if (ret) {
> +		dev_err(&pdev->dev, "failed to register notifier: %d\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int sc2731_charger_remove(struct platform_device *pdev)
> +{
> +	struct sc2731_charger_info *info = platform_get_drvdata(pdev);
> +
> +	usb_unregister_notifier(info->usb_phy, &info->usb_notify);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id sc2731_charger_of_match[] = {
> +	{ .compatible = "sprd,sc2731-charger", },
> +	{ }
> +};
> +
> +static struct platform_driver sc2731_charger_driver = {
> +	.driver = {
> +		.name = "sc2731-charger",
> +		.of_match_table = sc2731_charger_of_match,
> +	},
> +	.probe = sc2731_charger_probe,
> +	.remove = sc2731_charger_remove,
> +};
> +
> +module_platform_driver(sc2731_charger_driver);
> +
> +MODULE_DESCRIPTION("Spreadtrum SC2731 Charger Driver");
> +MODULE_LICENSE("GPL v2");
> -- 
> 1.7.9.5
>

(Exiting) Baolin Wang Sept. 17, 2018, 3:32 a.m. UTC | #3

Hi Sebastian,

On 16 September 2018 at 18:17, Sebastian Reichel
<[e-mail]> wrote:
> Hi Baolin,
>
> On Mon, Sep 03, 2018 at 04:55:46PM +0800, Baolin Wang wrote:
>> This patch adds the SC2731 PMIC switch charger support.
>>
>> Signed-off-by: Baolin Wang <[e-mail]>
>> ---
>
> The power-supply sysfs files uses uA instead of mA, otherwise the
> driver and the binding looks fine to me.

OK. Thanks for your reviewing.

>
> -- Sebastian
>
>> Changes from v1:
>>  - Remove some redundant head files.
>>  - Add one mutex to make sure getting the charger status is correct.
>>  - Fix some coding style issues.
>>  - Use standard DT properties.
>> ---
>>  drivers/power/supply/Kconfig          |    7 +
>>  drivers/power/supply/Makefile         |    1 +
>>  drivers/power/supply/sc2731_charger.c |  503 +++++++++++++++++++++++++++++++++
>>  3 files changed, 511 insertions(+)
>>  create mode 100644 drivers/power/supply/sc2731_charger.c
>>
>> diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
>> index ff6dab0..f27cf07 100644
>> --- a/drivers/power/supply/Kconfig
>> +++ b/drivers/power/supply/Kconfig
>> @@ -645,4 +645,11 @@ config CHARGER_CROS_USBPD
>>         what is connected to USB PD ports from the EC and converts
>>         that into power_supply properties.
>>
>> +config CHARGER_SC2731
>> +     tristate "Spreadtrum SC2731 charger driver"
>> +     depends on MFD_SC27XX_PMIC || COMPILE_TEST
>> +     help
>> +      Say Y here to enable support for battery charging with SC2731
>> +      PMIC chips.
>> +
>>  endif # POWER_SUPPLY
>> diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
>> index a26b402..767105b 100644
>> --- a/drivers/power/supply/Makefile
>> +++ b/drivers/power/supply/Makefile
>> @@ -85,3 +85,4 @@ obj-$(CONFIG_CHARGER_TPS65217)      += tps65217_charger.o
>>  obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
>>  obj-$(CONFIG_AXP288_CHARGER) += axp288_charger.o
>>  obj-$(CONFIG_CHARGER_CROS_USBPD)     += cros_usbpd-charger.o
>> +obj-$(CONFIG_CHARGER_SC2731) += sc2731_charger.o
>> diff --git a/drivers/power/supply/sc2731_charger.c b/drivers/power/supply/sc2731_charger.c
>> new file mode 100644
>> index 0000000..c92e5fc
>> --- /dev/null
>> +++ b/drivers/power/supply/sc2731_charger.c
>> @@ -0,0 +1,503 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +// Copyright (C) 2018 Spreadtrum Communications Inc.
>> +
>> +#include <linux/module.h>
>> +#include <linux/platform_device.h>
>> +#include <linux/power_supply.h>
>> +#include <linux/usb/phy.h>
>> +#include <linux/regmap.h>
>> +#include <linux/notifier.h>
>> +#include <linux/of.h>
>> +
>> +/* PMIC global registers definition */
>> +#define SC2731_CHARGE_STATUS         0xedc
>> +#define SC2731_CHARGE_FULL           BIT(4)
>> +#define SC2731_MODULE_EN1            0xc0c
>> +#define SC2731_CHARGE_EN             BIT(5)
>> +
>> +/* SC2731 switch charger registers definition */
>> +#define SC2731_CHG_CFG0                      0x0
>> +#define SC2731_CHG_CFG1                      0x4
>> +#define SC2731_CHG_CFG2                      0x8
>> +#define SC2731_CHG_CFG3                      0xc
>> +#define SC2731_CHG_CFG4                      0x10
>> +#define SC2731_CHG_CFG5                      0x28
>> +
>> +/* SC2731_CHG_CFG0 register definition */
>> +#define SC2731_PRECHG_RNG_SHIFT              11
>> +#define SC2731_PRECHG_RNG_MASK               GENMASK(12, 11)
>> +
>> +#define SC2731_TERMINATION_VOL_MASK  GENMASK(2, 1)
>> +#define SC2731_TERMINATION_VOL_SHIFT 1
>> +#define SC2731_TERMINATION_VOL_CAL_MASK      GENMASK(8, 3)
>> +#define SC2731_TERMINATION_VOL_CAL_SHIFT     3
>> +#define SC2731_TERMINATION_CUR_MASK  GENMASK(2, 0)
>> +
>> +#define SC2731_CC_EN                 BIT(13)
>> +#define SC2731_CHARGER_PD            BIT(0)
>> +
>> +/* SC2731_CHG_CFG1 register definition */
>> +#define SC2731_CUR_MASK                      GENMASK(5, 0)
>> +
>> +/* SC2731_CHG_CFG5 register definition */
>> +#define SC2731_CUR_LIMIT_SHIFT               8
>> +#define SC2731_CUR_LIMIT_MASK                GENMASK(9, 8)
>> +
>> +/* Default current definition (unit is mA) */
>> +#define SC2731_CURRENT_LIMIT_100     100
>> +#define SC2731_CURRENT_LIMIT_500     500
>> +#define SC2731_CURRENT_LIMIT_900     900
>> +#define SC2731_CURRENT_LIMIT_2000    2000
>> +#define SC2731_CURRENT_PRECHG                450
>> +#define SC2731_CURRENT_STEP          50
>> +
>> +struct sc2731_charger_info {
>> +     struct device *dev;
>> +     struct regmap *regmap;
>> +     struct usb_phy *usb_phy;
>> +     struct notifier_block usb_notify;
>> +     struct power_supply *psy_usb;
>> +     struct mutex lock;
>> +     bool charging;
>> +     u32 base;
>> +};
>> +
>> +static void sc2731_charger_stop_charge(struct sc2731_charger_info *info)
>> +{
>> +     regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                        SC2731_CC_EN, 0);
>> +
>> +     regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                        SC2731_CHARGER_PD, SC2731_CHARGER_PD);
>> +}
>> +
>> +static int sc2731_charger_start_charge(struct sc2731_charger_info *info)
>> +{
>> +     int ret;
>> +
>> +     /* Enable charger constant current mode */
>> +     ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                              SC2731_CC_EN, SC2731_CC_EN);
>> +     if (ret)
>> +             return ret;
>> +
>> +     /* Start charging */
>> +     return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                               SC2731_CHARGER_PD, 0);
>> +}
>> +
>> +static int sc2731_charger_set_current_limit(struct sc2731_charger_info *info,
>> +                                         u32 limit)
>> +{
>> +     u32 val;
>> +
>> +     if (limit <= SC2731_CURRENT_LIMIT_100)
>> +             val = 0;
>> +     else if (limit <= SC2731_CURRENT_LIMIT_500)
>> +             val = 3;
>> +     else if (limit <= SC2731_CURRENT_LIMIT_900)
>> +             val = 2;
>> +     else
>> +             val = 1;
>> +
>> +     return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG5,
>> +                               SC2731_CUR_LIMIT_MASK,
>> +                               val << SC2731_CUR_LIMIT_SHIFT);
>> +}
>> +
>> +static int sc2731_charger_set_current(struct sc2731_charger_info *info, u32 cur)
>> +{
>> +     u32 val;
>> +     int ret;
>> +
>> +     if (cur > SC2731_CURRENT_LIMIT_2000)
>> +             cur = SC2731_CURRENT_LIMIT_2000;
>> +     else if (cur < SC2731_CURRENT_PRECHG)
>> +             cur = SC2731_CURRENT_PRECHG;
>> +
>> +     /* Calculate the step value, each step is 50 mA */
>> +     val = (cur - SC2731_CURRENT_PRECHG) / SC2731_CURRENT_STEP;
>> +
>> +     /* Set pre-charge current as 450 mA */
>> +     ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                              SC2731_PRECHG_RNG_MASK,
>> +                              0x3 << SC2731_PRECHG_RNG_SHIFT);
>> +     if (ret)
>> +             return ret;
>> +
>> +     return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG1,
>> +                               SC2731_CUR_MASK, val);
>> +}
>> +
>> +static int sc2731_charger_get_status(struct sc2731_charger_info *info)
>> +{
>> +     u32 val;
>> +     int ret;
>> +
>> +     ret = regmap_read(info->regmap, SC2731_CHARGE_STATUS, &val);
>> +     if (ret)
>> +             return ret;
>> +
>> +     if (val & SC2731_CHARGE_FULL)
>> +             return POWER_SUPPLY_STATUS_FULL;
>> +
>> +     return POWER_SUPPLY_STATUS_CHARGING;
>> +}
>> +
>> +static int sc2731_charger_get_current(struct sc2731_charger_info *info,
>> +                                   u32 *cur)
>> +{
>> +     int ret;
>> +     u32 val;
>> +
>> +     ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG1, &val);
>> +     if (ret)
>> +             return ret;
>> +
>> +     val &= SC2731_CUR_MASK;
>> +     *cur = val * SC2731_CURRENT_STEP + SC2731_CURRENT_PRECHG;
>> +
>> +     return 0;
>> +}
>> +
>> +static int sc2731_charger_get_current_limit(struct sc2731_charger_info *info,
>> +                                         u32 *cur)
>> +{
>> +     int ret;
>> +     u32 val;
>> +
>> +     ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG5, &val);
>> +     if (ret)
>> +             return ret;
>> +
>> +     val = (val & SC2731_CUR_LIMIT_MASK) >> SC2731_CUR_LIMIT_SHIFT;
>> +
>> +     switch (val) {
>> +     case 0:
>> +             *cur = SC2731_CURRENT_LIMIT_100;
>> +             break;
>> +
>> +     case 1:
>> +             *cur = SC2731_CURRENT_LIMIT_2000;
>> +             break;
>> +
>> +     case 2:
>> +             *cur = SC2731_CURRENT_LIMIT_900;
>> +             break;
>> +
>> +     case 3:
>> +             *cur = SC2731_CURRENT_LIMIT_500;
>> +             break;
>> +
>> +     default:
>> +             return -EINVAL;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +static int
>> +sc2731_charger_usb_set_property(struct power_supply *psy,
>> +                             enum power_supply_property psp,
>> +                             const union power_supply_propval *val)
>> +{
>> +     struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
>> +     int ret;
>> +
>> +     mutex_lock(&info->lock);
>> +
>> +     if (!info->charging) {
>> +             mutex_unlock(&info->lock);
>> +             return -ENODEV;
>> +     }
>> +
>> +     switch (psp) {
>> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> +             ret = sc2731_charger_set_current(info, val->intval);
>> +             if (ret < 0)
>> +                     dev_err(info->dev, "set charge current failed\n");
>> +             break;
>
> This gets uA as input (instead of mA).

Yes. Sorry I missed this and will fix in next version.

>
>> +     case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> +             ret = sc2731_charger_set_current_limit(info, val->intval);
>> +             if (ret < 0)
>> +                     dev_err(info->dev, "set input current limit failed\n");
>> +             break;
>
> This gets uA as input (instead of mA).

OK.

>
>> +
>> +     default:
>> +             ret = -EINVAL;
>> +     }
>> +
>> +     mutex_unlock(&info->lock);
>> +     return ret;
>> +}
>> +
>> +static int sc2731_charger_usb_get_property(struct power_supply *psy,
>> +                                        enum power_supply_property psp,
>> +                                        union power_supply_propval *val)
>> +{
>> +     struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
>> +     int ret = 0;
>> +     u32 cur;
>> +
>> +     mutex_lock(&info->lock);
>> +
>> +     switch (psp) {
>> +     case POWER_SUPPLY_PROP_STATUS:
>> +             if (info->charging)
>> +                     val->intval = sc2731_charger_get_status(info);
>> +             else
>> +                     val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
>> +             break;
>> +
>> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> +             if (!info->charging) {
>> +                     val->intval = 0;
>> +             } else {
>> +                     ret = sc2731_charger_get_current(info, &cur);
>> +                     if (ret)
>> +                             goto out;
>> +
>> +                     val->intval = cur;
>> +             }
>> +             break;
>
> This should always report uA (instead of mA).

OK.

>
>> +     case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> +             if (!info->charging) {
>> +                     val->intval = 0;
>> +             } else {
>> +                     ret = sc2731_charger_get_current_limit(info, &cur);
>> +                     if (ret)
>> +                             goto out;
>> +
>> +                     val->intval = cur;
>> +             }
>> +             break;
>
> This should always report uA (instead of mA).

OK. Thanks.

>
>> +     default:
>> +             ret = -EINVAL;
>> +     }
>> +
>> +out:
>> +     mutex_unlock(&info->lock);
>> +     return ret;
>> +}
>> +
>> +static int sc2731_charger_property_is_writeable(struct power_supply *psy,
>> +                                             enum power_supply_property psp)
>> +{
>> +     int ret;
>> +
>> +     switch (psp) {
>> +     case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
>> +     case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
>> +             ret = 1;
>> +             break;
>> +
>> +     default:
>> +             ret = 0;
>> +     }
>> +
>> +     return ret;
>> +}
>> +
>> +static enum power_supply_property sc2731_usb_props[] = {
>> +     POWER_SUPPLY_PROP_STATUS,
>> +     POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
>> +     POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
>> +};
>> +
>> +static const struct power_supply_desc sc2731_charger_desc = {
>> +     .name                   = "sc2731_charger",
>> +     .type                   = POWER_SUPPLY_TYPE_USB,
>> +     .properties             = sc2731_usb_props,
>> +     .num_properties         = ARRAY_SIZE(sc2731_usb_props),
>> +     .get_property           = sc2731_charger_usb_get_property,
>> +     .set_property           = sc2731_charger_usb_set_property,
>> +     .property_is_writeable  = sc2731_charger_property_is_writeable,
>> +};
>> +
>> +static int sc2731_charger_usb_change(struct notifier_block *nb,
>> +                                  unsigned long limit, void *data)
>> +{
>> +     struct sc2731_charger_info *info =
>> +             container_of(nb, struct sc2731_charger_info, usb_notify);
>> +     int ret = 0;
>> +
>> +     mutex_lock(&info->lock);
>> +
>> +     if (limit > 0) {
>> +             /* set current limitation and start to charge */
>> +             ret = sc2731_charger_set_current_limit(info, limit);
>> +             if (ret)
>> +                     goto out;
>> +
>> +             ret = sc2731_charger_set_current(info, limit);
>> +             if (ret)
>> +                     goto out;
>> +
>> +             ret = sc2731_charger_start_charge(info);
>> +             if (ret)
>> +                     goto out;
>> +
>> +             info->charging = true;
>> +     } else {
>> +             /* Stop charging */
>> +             info->charging = false;
>> +             sc2731_charger_stop_charge(info);
>> +     }
>> +
>> +out:
>> +     mutex_unlock(&info->lock);
>> +     return ret;
>> +}
>> +
>> +static int sc2731_charger_hw_init(struct sc2731_charger_info *info)
>> +{
>> +     struct power_supply_battery_info bat_info = { };
>> +     u32 term_currrent, term_voltage, cur_val, vol_val;
>> +     int ret;
>> +
>> +     /* Enable charger module */
>> +     ret = regmap_update_bits(info->regmap, SC2731_MODULE_EN1,
>> +                              SC2731_CHARGE_EN, SC2731_CHARGE_EN);
>> +     if (ret)
>> +             return ret;
>> +
>> +     ret = power_supply_get_battery_info(info->psy_usb, &bat_info);
>> +     if (ret) {
>> +             dev_warn(info->dev, "no battery information is supplied\n");
>> +
>> +             /*
>> +              * If no battery information is supplied, we should set
>> +              * default charge termination current to 120 mA, and default
>> +              * charge termination voltage to 4.35V.
>> +              */
>> +             cur_val = 0x2;
>> +             vol_val = 0x1;
>> +     } else {
>> +             term_currrent = bat_info.charge_term_current_ua / 1000;
>> +
>> +             if (term_currrent <= 90)
>> +                     cur_val = 0;
>> +             else if (term_currrent >= 265)
>> +                     cur_val = 0x7;
>> +             else
>> +                     cur_val = ((term_currrent - 90) / 25) + 1;
>> +
>> +             term_voltage = bat_info.constant_charge_voltage_max_uv / 1000;
>> +
>> +             if (term_voltage > 4500)
>> +                     term_voltage = 4500;
>> +
>> +             if (term_voltage > 4200)
>> +                     vol_val = (term_voltage - 4200) / 100;
>> +             else
>> +                     vol_val = 0;
>> +     }
>> +
>> +     /* Set charge termination current */
>> +     ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG2,
>> +                              SC2731_TERMINATION_CUR_MASK, cur_val);
>> +     if (ret)
>> +             goto error;
>> +
>> +     /* Set charge termination voltage */
>> +     ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
>> +                              SC2731_TERMINATION_VOL_MASK |
>> +                              SC2731_TERMINATION_VOL_CAL_MASK,
>> +                              (vol_val << SC2731_TERMINATION_VOL_SHIFT) |
>> +                              (0x6 << SC2731_TERMINATION_VOL_CAL_SHIFT));
>> +     if (ret)
>> +             goto error;
>> +
>> +     return 0;
>> +
>> +error:
>> +     regmap_update_bits(info->regmap, SC2731_MODULE_EN1, SC2731_CHARGE_EN, 0);
>> +     return ret;
>> +}
>> +
>> +static int sc2731_charger_probe(struct platform_device *pdev)
>> +{
>> +     struct device_node *np = pdev->dev.of_node;
>> +     struct sc2731_charger_info *info;
>> +     struct power_supply_config charger_cfg = { };
>> +     int ret;
>> +
>> +     info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
>> +     if (!info)
>> +             return -ENOMEM;
>> +
>> +     mutex_init(&info->lock);
>> +     info->dev = &pdev->dev;
>> +
>> +     info->regmap = dev_get_regmap(pdev->dev.parent, NULL);
>> +     if (!info->regmap) {
>> +             dev_err(&pdev->dev, "failed to get charger regmap\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     ret = of_property_read_u32(np, "reg", &info->base);
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "failed to get register address\n");
>> +             return -ENODEV;
>> +     }
>> +
>> +     charger_cfg.drv_data = info;
>> +     charger_cfg.of_node = np;
>> +     info->psy_usb = devm_power_supply_register(&pdev->dev,
>> +                                                &sc2731_charger_desc,
>> +                                                &charger_cfg);
>> +     if (IS_ERR(info->psy_usb)) {
>> +             dev_err(&pdev->dev, "failed to register power supply\n");
>> +             return PTR_ERR(info->psy_usb);
>> +     }
>> +
>> +     ret = sc2731_charger_hw_init(info);
>> +     if (ret)
>> +             return ret;
>> +
>> +     info->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "phys", 0);
>> +     if (IS_ERR(info->usb_phy)) {
>> +             dev_err(&pdev->dev, "failed to find USB phy\n");
>> +             return PTR_ERR(info->usb_phy);
>> +     }
>> +
>> +     info->usb_notify.notifier_call = sc2731_charger_usb_change;
>> +     ret = usb_register_notifier(info->usb_phy, &info->usb_notify);
>> +     if (ret) {
>> +             dev_err(&pdev->dev, "failed to register notifier: %d\n", ret);
>> +             return ret;
>> +     }
>> +
>> +     return 0;
>> +}
>> +
>> +static int sc2731_charger_remove(struct platform_device *pdev)
>> +{
>> +     struct sc2731_charger_info *info = platform_get_drvdata(pdev);
>> +
>> +     usb_unregister_notifier(info->usb_phy, &info->usb_notify);
>> +
>> +     return 0;
>> +}
>> +
>> +static const struct of_device_id sc2731_charger_of_match[] = {
>> +     { .compatible = "sprd,sc2731-charger", },
>> +     { }
>> +};
>> +
>> +static struct platform_driver sc2731_charger_driver = {
>> +     .driver = {
>> +             .name = "sc2731-charger",
>> +             .of_match_table = sc2731_charger_of_match,
>> +     },
>> +     .probe = sc2731_charger_probe,
>> +     .remove = sc2731_charger_remove,
>> +};
>> +
>> +module_platform_driver(sc2731_charger_driver);
>> +
>> +MODULE_DESCRIPTION("Spreadtrum SC2731 Charger Driver");
>> +MODULE_LICENSE("GPL v2");
>> --
>> 1.7.9.5
>>

Patch

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index ff6dab0..f27cf07 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -645,4 +645,11 @@  config CHARGER_CROS_USBPD
 	  what is connected to USB PD ports from the EC and converts
 	  that into power_supply properties.
 
+config CHARGER_SC2731
+	tristate "Spreadtrum SC2731 charger driver"
+	depends on MFD_SC27XX_PMIC || COMPILE_TEST
+	help
+	 Say Y here to enable support for battery charging with SC2731
+	 PMIC chips.
+
 endif # POWER_SUPPLY
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index a26b402..767105b 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -85,3 +85,4 @@  obj-$(CONFIG_CHARGER_TPS65217)	+= tps65217_charger.o
 obj-$(CONFIG_AXP288_FUEL_GAUGE) += axp288_fuel_gauge.o
 obj-$(CONFIG_AXP288_CHARGER)	+= axp288_charger.o
 obj-$(CONFIG_CHARGER_CROS_USBPD)	+= cros_usbpd-charger.o
+obj-$(CONFIG_CHARGER_SC2731)	+= sc2731_charger.o
diff --git a/drivers/power/supply/sc2731_charger.c b/drivers/power/supply/sc2731_charger.c
new file mode 100644
index 0000000..c92e5fc
--- /dev/null
+++ b/drivers/power/supply/sc2731_charger.c
@@ -0,0 +1,503 @@ 
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Spreadtrum Communications Inc.
+
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/usb/phy.h>
+#include <linux/regmap.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+
+/* PMIC global registers definition */
+#define SC2731_CHARGE_STATUS		0xedc
+#define SC2731_CHARGE_FULL		BIT(4)
+#define SC2731_MODULE_EN1		0xc0c
+#define SC2731_CHARGE_EN		BIT(5)
+
+/* SC2731 switch charger registers definition */
+#define SC2731_CHG_CFG0			0x0
+#define SC2731_CHG_CFG1			0x4
+#define SC2731_CHG_CFG2			0x8
+#define SC2731_CHG_CFG3			0xc
+#define SC2731_CHG_CFG4			0x10
+#define SC2731_CHG_CFG5			0x28
+
+/* SC2731_CHG_CFG0 register definition */
+#define SC2731_PRECHG_RNG_SHIFT		11
+#define SC2731_PRECHG_RNG_MASK		GENMASK(12, 11)
+
+#define SC2731_TERMINATION_VOL_MASK	GENMASK(2, 1)
+#define SC2731_TERMINATION_VOL_SHIFT	1
+#define SC2731_TERMINATION_VOL_CAL_MASK	GENMASK(8, 3)
+#define SC2731_TERMINATION_VOL_CAL_SHIFT	3
+#define SC2731_TERMINATION_CUR_MASK	GENMASK(2, 0)
+
+#define SC2731_CC_EN			BIT(13)
+#define SC2731_CHARGER_PD		BIT(0)
+
+/* SC2731_CHG_CFG1 register definition */
+#define SC2731_CUR_MASK			GENMASK(5, 0)
+
+/* SC2731_CHG_CFG5 register definition */
+#define SC2731_CUR_LIMIT_SHIFT		8
+#define SC2731_CUR_LIMIT_MASK		GENMASK(9, 8)
+
+/* Default current definition (unit is mA) */
+#define SC2731_CURRENT_LIMIT_100	100
+#define SC2731_CURRENT_LIMIT_500	500
+#define SC2731_CURRENT_LIMIT_900	900
+#define SC2731_CURRENT_LIMIT_2000	2000
+#define SC2731_CURRENT_PRECHG		450
+#define SC2731_CURRENT_STEP		50
+
+struct sc2731_charger_info {
+	struct device *dev;
+	struct regmap *regmap;
+	struct usb_phy *usb_phy;
+	struct notifier_block usb_notify;
+	struct power_supply *psy_usb;
+	struct mutex lock;
+	bool charging;
+	u32 base;
+};
+
+static void sc2731_charger_stop_charge(struct sc2731_charger_info *info)
+{
+	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+			   SC2731_CC_EN, 0);
+
+	regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+			   SC2731_CHARGER_PD, SC2731_CHARGER_PD);
+}
+
+static int sc2731_charger_start_charge(struct sc2731_charger_info *info)
+{
+	int ret;
+
+	/* Enable charger constant current mode */
+	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+				 SC2731_CC_EN, SC2731_CC_EN);
+	if (ret)
+		return ret;
+
+	/* Start charging */
+	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+				  SC2731_CHARGER_PD, 0);
+}
+
+static int sc2731_charger_set_current_limit(struct sc2731_charger_info *info,
+					    u32 limit)
+{
+	u32 val;
+
+	if (limit <= SC2731_CURRENT_LIMIT_100)
+		val = 0;
+	else if (limit <= SC2731_CURRENT_LIMIT_500)
+		val = 3;
+	else if (limit <= SC2731_CURRENT_LIMIT_900)
+		val = 2;
+	else
+		val = 1;
+
+	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG5,
+				  SC2731_CUR_LIMIT_MASK,
+				  val << SC2731_CUR_LIMIT_SHIFT);
+}
+
+static int sc2731_charger_set_current(struct sc2731_charger_info *info, u32 cur)
+{
+	u32 val;
+	int ret;
+
+	if (cur > SC2731_CURRENT_LIMIT_2000)
+		cur = SC2731_CURRENT_LIMIT_2000;
+	else if (cur < SC2731_CURRENT_PRECHG)
+		cur = SC2731_CURRENT_PRECHG;
+
+	/* Calculate the step value, each step is 50 mA */
+	val = (cur - SC2731_CURRENT_PRECHG) / SC2731_CURRENT_STEP;
+
+	/* Set pre-charge current as 450 mA */
+	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+				 SC2731_PRECHG_RNG_MASK,
+				 0x3 << SC2731_PRECHG_RNG_SHIFT);
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG1,
+				  SC2731_CUR_MASK, val);
+}
+
+static int sc2731_charger_get_status(struct sc2731_charger_info *info)
+{
+	u32 val;
+	int ret;
+
+	ret = regmap_read(info->regmap, SC2731_CHARGE_STATUS, &val);
+	if (ret)
+		return ret;
+
+	if (val & SC2731_CHARGE_FULL)
+		return POWER_SUPPLY_STATUS_FULL;
+
+	return POWER_SUPPLY_STATUS_CHARGING;
+}
+
+static int sc2731_charger_get_current(struct sc2731_charger_info *info,
+				      u32 *cur)
+{
+	int ret;
+	u32 val;
+
+	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG1, &val);
+	if (ret)
+		return ret;
+
+	val &= SC2731_CUR_MASK;
+	*cur = val * SC2731_CURRENT_STEP + SC2731_CURRENT_PRECHG;
+
+	return 0;
+}
+
+static int sc2731_charger_get_current_limit(struct sc2731_charger_info *info,
+					    u32 *cur)
+{
+	int ret;
+	u32 val;
+
+	ret = regmap_read(info->regmap, info->base + SC2731_CHG_CFG5, &val);
+	if (ret)
+		return ret;
+
+	val = (val & SC2731_CUR_LIMIT_MASK) >> SC2731_CUR_LIMIT_SHIFT;
+
+	switch (val) {
+	case 0:
+		*cur = SC2731_CURRENT_LIMIT_100;
+		break;
+
+	case 1:
+		*cur = SC2731_CURRENT_LIMIT_2000;
+		break;
+
+	case 2:
+		*cur = SC2731_CURRENT_LIMIT_900;
+		break;
+
+	case 3:
+		*cur = SC2731_CURRENT_LIMIT_500;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int
+sc2731_charger_usb_set_property(struct power_supply *psy,
+				enum power_supply_property psp,
+				const union power_supply_propval *val)
+{
+	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
+	int ret;
+
+	mutex_lock(&info->lock);
+
+	if (!info->charging) {
+		mutex_unlock(&info->lock);
+		return -ENODEV;
+	}
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		ret = sc2731_charger_set_current(info, val->intval);
+		if (ret < 0)
+			dev_err(info->dev, "set charge current failed\n");
+		break;
+
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		ret = sc2731_charger_set_current_limit(info, val->intval);
+		if (ret < 0)
+			dev_err(info->dev, "set input current limit failed\n");
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+
+	mutex_unlock(&info->lock);
+	return ret;
+}
+
+static int sc2731_charger_usb_get_property(struct power_supply *psy,
+					   enum power_supply_property psp,
+					   union power_supply_propval *val)
+{
+	struct sc2731_charger_info *info = power_supply_get_drvdata(psy);
+	int ret = 0;
+	u32 cur;
+
+	mutex_lock(&info->lock);
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (info->charging)
+			val->intval = sc2731_charger_get_status(info);
+		else
+			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
+		break;
+
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+		if (!info->charging) {
+			val->intval = 0;
+		} else {
+			ret = sc2731_charger_get_current(info, &cur);
+			if (ret)
+				goto out;
+
+			val->intval = cur;
+		}
+		break;
+
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		if (!info->charging) {
+			val->intval = 0;
+		} else {
+			ret = sc2731_charger_get_current_limit(info, &cur);
+			if (ret)
+				goto out;
+
+			val->intval = cur;
+		}
+		break;
+
+	default:
+		ret = -EINVAL;
+	}
+
+out:
+	mutex_unlock(&info->lock);
+	return ret;
+}
+
+static int sc2731_charger_property_is_writeable(struct power_supply *psy,
+						enum power_supply_property psp)
+{
+	int ret;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT:
+	case POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT:
+		ret = 1;
+		break;
+
+	default:
+		ret = 0;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property sc2731_usb_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_CONSTANT_CHARGE_CURRENT,
+	POWER_SUPPLY_PROP_INPUT_CURRENT_LIMIT,
+};
+
+static const struct power_supply_desc sc2731_charger_desc = {
+	.name			= "sc2731_charger",
+	.type			= POWER_SUPPLY_TYPE_USB,
+	.properties		= sc2731_usb_props,
+	.num_properties		= ARRAY_SIZE(sc2731_usb_props),
+	.get_property		= sc2731_charger_usb_get_property,
+	.set_property		= sc2731_charger_usb_set_property,
+	.property_is_writeable	= sc2731_charger_property_is_writeable,
+};
+
+static int sc2731_charger_usb_change(struct notifier_block *nb,
+				     unsigned long limit, void *data)
+{
+	struct sc2731_charger_info *info =
+		container_of(nb, struct sc2731_charger_info, usb_notify);
+	int ret = 0;
+
+	mutex_lock(&info->lock);
+
+	if (limit > 0) {
+		/* set current limitation and start to charge */
+		ret = sc2731_charger_set_current_limit(info, limit);
+		if (ret)
+			goto out;
+
+		ret = sc2731_charger_set_current(info, limit);
+		if (ret)
+			goto out;
+
+		ret = sc2731_charger_start_charge(info);
+		if (ret)
+			goto out;
+
+		info->charging = true;
+	} else {
+		/* Stop charging */
+		info->charging = false;
+		sc2731_charger_stop_charge(info);
+	}
+
+out:
+	mutex_unlock(&info->lock);
+	return ret;
+}
+
+static int sc2731_charger_hw_init(struct sc2731_charger_info *info)
+{
+	struct power_supply_battery_info bat_info = { };
+	u32 term_currrent, term_voltage, cur_val, vol_val;
+	int ret;
+
+	/* Enable charger module */
+	ret = regmap_update_bits(info->regmap, SC2731_MODULE_EN1,
+				 SC2731_CHARGE_EN, SC2731_CHARGE_EN);
+	if (ret)
+		return ret;
+
+	ret = power_supply_get_battery_info(info->psy_usb, &bat_info);
+	if (ret) {
+		dev_warn(info->dev, "no battery information is supplied\n");
+
+		/*
+		 * If no battery information is supplied, we should set
+		 * default charge termination current to 120 mA, and default
+		 * charge termination voltage to 4.35V.
+		 */
+		cur_val = 0x2;
+		vol_val = 0x1;
+	} else {
+		term_currrent = bat_info.charge_term_current_ua / 1000;
+
+		if (term_currrent <= 90)
+			cur_val = 0;
+		else if (term_currrent >= 265)
+			cur_val = 0x7;
+		else
+			cur_val = ((term_currrent - 90) / 25) + 1;
+
+		term_voltage = bat_info.constant_charge_voltage_max_uv / 1000;
+
+		if (term_voltage > 4500)
+			term_voltage = 4500;
+
+		if (term_voltage > 4200)
+			vol_val = (term_voltage - 4200) / 100;
+		else
+			vol_val = 0;
+	}
+
+	/* Set charge termination current */
+	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG2,
+				 SC2731_TERMINATION_CUR_MASK, cur_val);
+	if (ret)
+		goto error;
+
+	/* Set charge termination voltage */
+	ret = regmap_update_bits(info->regmap, info->base + SC2731_CHG_CFG0,
+				 SC2731_TERMINATION_VOL_MASK |
+				 SC2731_TERMINATION_VOL_CAL_MASK,
+				 (vol_val << SC2731_TERMINATION_VOL_SHIFT) |
+				 (0x6 << SC2731_TERMINATION_VOL_CAL_SHIFT));
+	if (ret)
+		goto error;
+
+	return 0;
+
+error:
+	regmap_update_bits(info->regmap, SC2731_MODULE_EN1, SC2731_CHARGE_EN, 0);
+	return ret;
+}
+
+static int sc2731_charger_probe(struct platform_device *pdev)
+{
+	struct device_node *np = pdev->dev.of_node;
+	struct sc2731_charger_info *info;
+	struct power_supply_config charger_cfg = { };
+	int ret;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	mutex_init(&info->lock);
+	info->dev = &pdev->dev;
+
+	info->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+	if (!info->regmap) {
+		dev_err(&pdev->dev, "failed to get charger regmap\n");
+		return -ENODEV;
+	}
+
+	ret = of_property_read_u32(np, "reg", &info->base);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get register address\n");
+		return -ENODEV;
+	}
+
+	charger_cfg.drv_data = info;
+	charger_cfg.of_node = np;
+	info->psy_usb = devm_power_supply_register(&pdev->dev,
+						   &sc2731_charger_desc,
+						   &charger_cfg);
+	if (IS_ERR(info->psy_usb)) {
+		dev_err(&pdev->dev, "failed to register power supply\n");
+		return PTR_ERR(info->psy_usb);
+	}
+
+	ret = sc2731_charger_hw_init(info);
+	if (ret)
+		return ret;
+
+	info->usb_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "phys", 0);
+	if (IS_ERR(info->usb_phy)) {
+		dev_err(&pdev->dev, "failed to find USB phy\n");
+		return PTR_ERR(info->usb_phy);
+	}
+
+	info->usb_notify.notifier_call = sc2731_charger_usb_change;
+	ret = usb_register_notifier(info->usb_phy, &info->usb_notify);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register notifier: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int sc2731_charger_remove(struct platform_device *pdev)
+{
+	struct sc2731_charger_info *info = platform_get_drvdata(pdev);
+
+	usb_unregister_notifier(info->usb_phy, &info->usb_notify);
+
+	return 0;
+}
+
+static const struct of_device_id sc2731_charger_of_match[] = {
+	{ .compatible = "sprd,sc2731-charger", },
+	{ }
+};
+
+static struct platform_driver sc2731_charger_driver = {
+	.driver = {
+		.name = "sc2731-charger",
+		.of_match_table = sc2731_charger_of_match,
+	},
+	.probe = sc2731_charger_probe,
+	.remove = sc2731_charger_remove,
+};
+
+module_platform_driver(sc2731_charger_driver);
+
+MODULE_DESCRIPTION("Spreadtrum SC2731 Charger Driver");
+MODULE_LICENSE("GPL v2");