Re: [PATCH v8 1/2] power: act8945a: add charger driver for ACT8945A

[Krzysztof Kozlowski <k.kozlowski@samsung.com>]

On 05.02.2016 13:26, Wenyou Yang wrote:
> This patch adds new driver for Active-semi ACT8945A ActivePath
> charger (part of ACT8945A MFD driver) providing power supply class
> information to userspace.
> 
> The driver can be configured through DT (such as, total timer,
> precondition timer and input over-voltage threshold).
> 
> Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
> ---
> 
> Changes in v8:
>  - remove the OF table.
>  - due to the mfd cell .of_compatible removal, use the platform
>    device's parent of_node to read the property and assign it
>    to the psy_cfg.of_node.
>  - fix the typo.
> 
> Changes in v7:
>  - use the helper dev_get_regmap(pdev->dev.parent, NULL) to get regmap.
>  - remove *act8945a_dev member from struct act8945a_charger.
>  - remove *psy member from struct act8945a_charger.
>  - merge _parse_dt() and _charger_config() functions, remove relevent
>    members from struct act8945a_charger.
>  - remove unused platform_set_drvdata(pdev, charger) statement.
> 
> Changes in v6:
>  - change the type value to unsigned int.
> 
> Changes in v5:
>  - remove spare spaces after #define.
>  - add OF match table.
> 
> Changes in v4:
>  - use spaces after #define, not tabs.
>  - use BIT(n) macros to substitute (0x01 << x).
>  - change dt properties with more legible name.
> 
> Changes in v3:
>  - update the file header with short version license and author line.
>  - remove unused member of struct act8945a_charger, dev.
>  - action due to removing the member of stuct act8945a_dev, dev.
>  - remove the unnecessary print out.
>  - remove the unnecessary act8945a_charger_remove().
>  - fix align of the code-style.
> 
> Changes in v2:
>  1./ Substitute of_property_read_bool() for of_get_property().
>  2./ Substitute devm_power_supply_register() for power_supply_register().
>  3./ Use module_platform_driver(), instead of subsys_initcall().
>  4./ Substitute MODULE_LICENSE("GPL") for MODULE_LICENSE("GPL v2").
> 
>  drivers/power/Kconfig            |    7 +
>  drivers/power/Makefile           |    1 +
>  drivers/power/act8945a_charger.c |  355 ++++++++++++++++++++++++++++++++++++++
>  3 files changed, 363 insertions(+)
>  create mode 100644 drivers/power/act8945a_charger.c
> 
> diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
> index 1ddd13c..ae75211 100644
> --- a/drivers/power/Kconfig
> +++ b/drivers/power/Kconfig
> @@ -75,6 +75,13 @@ config BATTERY_88PM860X
>  	help
>  	  Say Y here to enable battery monitor for Marvell 88PM860x chip.
>  
> +config BATTERY_ACT8945A
> +	tristate "Active-semi ACT8945A charger driver"
> +	depends on MFD_ACT8945A
> +	help
> +	  Say Y here to enable support for power supply provided by
> +	  Active-semi ActivePath ACT8945A charger.
> +
>  config BATTERY_DS2760
>  	tristate "DS2760 battery driver (HP iPAQ & others)"
>  	depends on W1 && W1_SLAVE_DS2760
> diff --git a/drivers/power/Makefile b/drivers/power/Makefile
> index 0e4eab5..e46b75d 100644
> --- a/drivers/power/Makefile
> +++ b/drivers/power/Makefile
> @@ -17,6 +17,7 @@ obj-$(CONFIG_WM8350_POWER)	+= wm8350_power.o
>  obj-$(CONFIG_TEST_POWER)	+= test_power.o
>  
>  obj-$(CONFIG_BATTERY_88PM860X)	+= 88pm860x_battery.o
> +obj-$(CONFIG_BATTERY_ACT8945A)	+= act8945a_charger.o
>  obj-$(CONFIG_BATTERY_DS2760)	+= ds2760_battery.o
>  obj-$(CONFIG_BATTERY_DS2780)	+= ds2780_battery.o
>  obj-$(CONFIG_BATTERY_DS2781)	+= ds2781_battery.o
> diff --git a/drivers/power/act8945a_charger.c b/drivers/power/act8945a_charger.c
> new file mode 100644
> index 0000000..0da0ea5
> --- /dev/null
> +++ b/drivers/power/act8945a_charger.c
> @@ -0,0 +1,355 @@
> +/*
> + * Power supply driver for the Active-semi ACT8945A PMIC
> + *
> + * Copyright (C) 2015 Atmel Corporation
> + *
> + * Author: Wenyou Yang <wenyou.yang@atmel.com>
> + *
> + * 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/module.h>
> +#include <linux/of.h>
> +#include <linux/of_gpio.h>
> +#include <linux/platform_device.h>
> +#include <linux/power_supply.h>
> +#include <linux/regmap.h>
> +
> +static const char *act8945a_charger_model = "ACT8945A";
> +static const char *act8945a_charger_manufacturer = "Active-semi";
> +
> +/**
> + * ACT8945A Charger Register Map
> + */
> +
> +/* 0x70: Reserved */
> +#define ACT8945A_APCH_CFG		0x71
> +#define ACT8945A_APCH_STATUS		0x78
> +#define ACT8945A_APCH_CTRL		0x79
> +#define ACT8945A_APCH_STATE		0x7A
> +
> +/* ACT8945A_APCH_CFG */
> +#define APCH_CFG_OVPSET			(0x3 << 0)
> +#define APCH_CFG_OVPSET_6V6		(0x0 << 0)
> +#define APCH_CFG_OVPSET_7V		(0x1 << 0)
> +#define APCH_CFG_OVPSET_7V5		(0x2 << 0)
> +#define APCH_CFG_OVPSET_8V		(0x3 << 0)
> +#define APCH_CFG_PRETIMO		(0x3 << 2)
> +#define APCH_CFG_PRETIMO_40_MIN		(0x0 << 2)
> +#define APCH_CFG_PRETIMO_60_MIN		(0x1 << 2)
> +#define APCH_CFG_PRETIMO_80_MIN		(0x2 << 2)
> +#define APCH_CFG_PRETIMO_DISABLED	(0x3 << 2)
> +#define APCH_CFG_TOTTIMO		(0x3 << 4)
> +#define APCH_CFG_TOTTIMO_3_HOUR		(0x0 << 4)
> +#define APCH_CFG_TOTTIMO_4_HOUR		(0x1 << 4)
> +#define APCH_CFG_TOTTIMO_5_HOUR		(0x2 << 4)
> +#define APCH_CFG_TOTTIMO_DISABLED	(0x3 << 4)
> +#define APCH_CFG_SUSCHG			(0x1 << 7)
> +
> +#define APCH_STATUS_CHGDAT		BIT(0)
> +#define APCH_STATUS_INDAT		BIT(1)
> +#define APCH_STATUS_TEMPDAT		BIT(2)
> +#define APCH_STATUS_TIMRDAT		BIT(3)
> +#define APCH_STATUS_CHGSTAT		BIT(4)
> +#define APCH_STATUS_INSTAT		BIT(5)
> +#define APCH_STATUS_TEMPSTAT		BIT(6)
> +#define APCH_STATUS_TIMRSTAT		BIT(7)
> +
> +#define APCH_CTRL_CHGEOCOUT		BIT(0)
> +#define APCH_CTRL_INDIS			BIT(1)
> +#define APCH_CTRL_TEMPOUT		BIT(2)
> +#define APCH_CTRL_TIMRPRE		BIT(3)
> +#define APCH_CTRL_CHGEOCIN		BIT(4)
> +#define APCH_CTRL_INCON			BIT(5)
> +#define APCH_CTRL_TEMPIN		BIT(6)
> +#define APCH_CTRL_TIMRTOT		BIT(7)
> +
> +#define APCH_STATE_ACINSTAT		(0x1 << 1)
> +#define APCH_STATE_CSTATE		(0x3 << 4)
> +#define APCH_STATE_CSTATE_SHIFT		4
> +#define APCH_STATE_CSTATE_DISABLED	0x00
> +#define APCH_STATE_CSTATE_EOC		0x01
> +#define APCH_STATE_CSTATE_FAST		0x02
> +#define APCH_STATE_CSTATE_PRE		0x03
> +
> +struct act8945a_charger {
> +	struct regmap *regmap;
> +	bool battery_temperature;
> +};
> +
> +static int act8945a_get_charger_state(struct regmap *regmap, int *val)
> +{
> +	int ret;
> +	unsigned int status, state;
> +
> +	ret = regmap_read(regmap, ACT8945A_APCH_STATUS, &status);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regmap_read(regmap, ACT8945A_APCH_STATE, &state);
> +	if (ret < 0)
> +		return ret;
> +
> +	state &= APCH_STATE_CSTATE;
> +	state >>= APCH_STATE_CSTATE_SHIFT;
> +
> +	if (state == APCH_STATE_CSTATE_EOC) {
> +		if (status & APCH_STATUS_CHGDAT)
> +			*val = POWER_SUPPLY_STATUS_FULL;
> +		else
> +			*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +	} else if ((state == APCH_STATE_CSTATE_FAST) ||
> +		   (state == APCH_STATE_CSTATE_PRE)) {
> +		*val = POWER_SUPPLY_STATUS_CHARGING;
> +	} else {
> +		*val = POWER_SUPPLY_STATUS_NOT_CHARGING;
> +	}
> +
> +	return 0;
> +}
> +
> +static int act8945a_get_charge_type(struct regmap *regmap, int *val)
> +{
> +	int ret;
> +	unsigned int state;
> +
> +	ret = regmap_read(regmap, ACT8945A_APCH_STATE, &state);
> +	if (ret < 0)
> +		return ret;
> +
> +	state &= APCH_STATE_CSTATE;
> +	state >>= APCH_STATE_CSTATE_SHIFT;
> +
> +	switch (state) {
> +	case APCH_STATE_CSTATE_PRE:
> +		*val = POWER_SUPPLY_CHARGE_TYPE_TRICKLE;
> +		break;
> +	case APCH_STATE_CSTATE_FAST:
> +		*val = POWER_SUPPLY_CHARGE_TYPE_FAST;
> +		break;
> +	case APCH_STATE_CSTATE_EOC:
> +	case APCH_STATE_CSTATE_DISABLED:
> +	default:
> +		*val = POWER_SUPPLY_CHARGE_TYPE_NONE;
> +	}
> +
> +	return 0;
> +}
> +
> +static int act8945a_get_battery_health(struct act8945a_charger *charger,
> +				       struct regmap *regmap, int *val)
> +{
> +	int ret;
> +	unsigned int status;
> +
> +	ret = regmap_read(regmap, ACT8945A_APCH_STATUS, &status);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (charger->battery_temperature && !(status & APCH_STATUS_TEMPDAT))
> +		*val = POWER_SUPPLY_HEALTH_OVERHEAT;
> +	else if (!(status & APCH_STATUS_INDAT))
> +		*val = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
> +	else if (status & APCH_STATUS_TIMRDAT)
> +		*val = POWER_SUPPLY_HEALTH_SAFETY_TIMER_EXPIRE;
> +	else
> +		*val = POWER_SUPPLY_HEALTH_GOOD;
> +
> +	return 0;
> +}
> +
> +static enum power_supply_property act8945a_charger_props[] = {
> +	POWER_SUPPLY_PROP_STATUS,
> +	POWER_SUPPLY_PROP_CHARGE_TYPE,
> +	POWER_SUPPLY_PROP_TECHNOLOGY,
> +	POWER_SUPPLY_PROP_HEALTH,
> +	POWER_SUPPLY_PROP_MODEL_NAME,
> +	POWER_SUPPLY_PROP_MANUFACTURER
> +};
> +
> +static int act8945a_charger_get_property(struct power_supply *psy,
> +					 enum power_supply_property prop,
> +					 union power_supply_propval *val)
> +{
> +	struct act8945a_charger *charger = power_supply_get_drvdata(psy);
> +	struct regmap *regmap = charger->regmap;
> +	int ret = 0;
> +
> +	switch (prop) {
> +	case POWER_SUPPLY_PROP_STATUS:
> +		ret = act8945a_get_charger_state(regmap, &val->intval);
> +		break;
> +	case POWER_SUPPLY_PROP_CHARGE_TYPE:
> +		ret = act8945a_get_charge_type(regmap, &val->intval);
> +		break;
> +	case POWER_SUPPLY_PROP_TECHNOLOGY:
> +		val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
> +		break;
> +	case POWER_SUPPLY_PROP_HEALTH:
> +		ret = act8945a_get_battery_health(charger,
> +						  regmap, &val->intval);
> +		break;
> +	case POWER_SUPPLY_PROP_MODEL_NAME:
> +		val->strval = act8945a_charger_model;
> +		break;
> +	case POWER_SUPPLY_PROP_MANUFACTURER:
> +		val->strval = act8945a_charger_manufacturer;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return ret;
> +}
> +
> +static const struct power_supply_desc act8945a_charger_desc = {
> +	.name		= "act8945a-charger",
> +	.type		= POWER_SUPPLY_TYPE_BATTERY,
> +	.get_property	= act8945a_charger_get_property,
> +	.properties	= act8945a_charger_props,
> +	.num_properties	= ARRAY_SIZE(act8945a_charger_props),
> +};
> +
> +#define DEFAULT_TOTAL_TIME_OUT		3
> +#define DEFAULT_PRE_TIME_OUT		40
> +#define DEFAULT_INPUT_OVP_THRESHOLD	6600
> +
> +static int act8945a_charger_config(struct device *dev,
> +				   struct act8945a_charger *charger)
> +{
> +	struct device_node *np = dev->of_node;
> +	enum of_gpio_flags flags;
> +	struct regmap *regmap = charger->regmap;
> +
> +	u32 total_time_out;
> +	u32 pre_time_out;
> +	u32 input_voltage_threshold;
> +	int chglev_pin;
> +
> +	unsigned int value = 0;
> +
> +	if (!np) {
> +		dev_err(dev, "no charger of node\n");
> +		return -EINVAL;
> +	}
> +
> +	charger->battery_temperature = of_property_read_bool(np,
> +				"active-semi,check-battery-temperature");
> +
> +	chglev_pin = of_get_named_gpio_flags(np,
> +				"active-semi,chglev-gpios", 0, &flags);
> +
> +	if (gpio_is_valid(chglev_pin)) {
> +		gpio_set_value(chglev_pin,
> +			       ((flags == OF_GPIO_ACTIVE_LOW) ? 0 : 1));
> +	}
> +
> +	if (of_property_read_u32(np,
> +				 "active-semi,input-voltage-threshold-microvolt",
> +				 &input_voltage_threshold))
> +		input_voltage_threshold = DEFAULT_INPUT_OVP_THRESHOLD;
> +
> +	if (of_property_read_u32(np,
> +				 "active-semi,precondition-timeout",
> +				 &pre_time_out))
> +		pre_time_out = DEFAULT_PRE_TIME_OUT;
> +
> +	if (of_property_read_u32(np, "active-semi,total-timeout",
> +				 &total_time_out))
> +		total_time_out = DEFAULT_TOTAL_TIME_OUT;
> +
> +	switch (input_voltage_threshold) {
> +	case 8000:
> +		value |= APCH_CFG_OVPSET_8V;
> +		break;
> +	case 7500:
> +		value |= APCH_CFG_OVPSET_7V5;
> +		break;
> +	case 7000:
> +		value |= APCH_CFG_OVPSET_7V;
> +		break;
> +	case 6600:
> +	default:
> +		value |= APCH_CFG_OVPSET_6V6;
> +		break;
> +	}
> +
> +	switch (pre_time_out) {
> +	case 60:
> +		value |= APCH_CFG_PRETIMO_60_MIN;
> +		break;
> +	case 80:
> +		value |= APCH_CFG_PRETIMO_80_MIN;
> +		break;
> +	case 0:
> +		value |= APCH_CFG_PRETIMO_DISABLED;
> +		break;
> +	case 40:
> +	default:
> +		value |= APCH_CFG_PRETIMO_40_MIN;
> +		break;
> +	}
> +
> +	switch (total_time_out) {
> +	case 4:
> +		value |= APCH_CFG_TOTTIMO_4_HOUR;
> +		break;
> +	case 5:
> +		value |= APCH_CFG_TOTTIMO_5_HOUR;
> +		break;
> +	case 0:
> +		value |= APCH_CFG_TOTTIMO_DISABLED;
> +		break;
> +	case 3:
> +	default:
> +		value |= APCH_CFG_TOTTIMO_3_HOUR;
> +		break;
> +	}
> +
> +	return regmap_write(regmap, ACT8945A_APCH_CFG, value);
> +}
> +
> +static int act8945a_charger_probe(struct platform_device *pdev)
> +{
> +	struct act8945a_charger *charger;
> +	struct power_supply *psy;
> +	struct power_supply_config psy_cfg = {};
> +	int ret;
> +
> +	charger = devm_kzalloc(&pdev->dev, sizeof(*charger), GFP_KERNEL);
> +	if (!charger)
> +		return -ENOMEM;
> +
> +	charger->regmap = dev_get_regmap(pdev->dev.parent, NULL);

I think it would be good (as a precaution) to check for non-null here:
if (!charger->regmap) {
	dev_err(... "Parent did not provide regmap\n");
	return -EINVAL;
}

Beside that:

Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

Best regards,
Krzysztof