[mirror_ubuntu-kernels.git] / drivers / power / supply / sbs-charger.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016, Prodys S.L.
 *
 * This adds support for sbs-charger compilant chips as defined here:
 * http://sbs-forum.org/specs/sbc110.pdf
 *
 * Implemetation based on sbs-battery.c
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/power_supply.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/bitops.h>
#include <linux/devm-helpers.h>

#define SBS_CHARGER_REG_SPEC_INFO		0x11
#define SBS_CHARGER_REG_STATUS			0x13
#define SBS_CHARGER_REG_ALARM_WARNING		0x16

#define SBS_CHARGER_STATUS_CHARGE_INHIBITED	BIT(0)
#define SBS_CHARGER_STATUS_RES_COLD		BIT(9)
#define SBS_CHARGER_STATUS_RES_HOT		BIT(10)
#define SBS_CHARGER_STATUS_BATTERY_PRESENT	BIT(14)
#define SBS_CHARGER_STATUS_AC_PRESENT		BIT(15)

#define SBS_CHARGER_POLL_TIME			500

struct sbs_info {
	struct i2c_client		*client;
	struct power_supply		*power_supply;
	struct regmap			*regmap;
	struct delayed_work		work;
	unsigned int			last_state;
};

static int sbs_get_property(struct power_supply *psy,
			    enum power_supply_property psp,
			    union power_supply_propval *val)
{
	struct sbs_info *chip = power_supply_get_drvdata(psy);
	unsigned int reg;

	reg = chip->last_state;

	switch (psp) {
	case POWER_SUPPLY_PROP_PRESENT:
		val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT);
		break;

	case POWER_SUPPLY_PROP_ONLINE:
		val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT);
		break;

	case POWER_SUPPLY_PROP_STATUS:
		val->intval = POWER_SUPPLY_STATUS_UNKNOWN;

		if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT))
			val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
		else if (reg & SBS_CHARGER_STATUS_AC_PRESENT &&
			 !(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED))
			val->intval = POWER_SUPPLY_STATUS_CHARGING;
		else
			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;

		break;

	case POWER_SUPPLY_PROP_HEALTH:
		if (reg & SBS_CHARGER_STATUS_RES_COLD)
			val->intval = POWER_SUPPLY_HEALTH_COLD;
		if (reg & SBS_CHARGER_STATUS_RES_HOT)
			val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
		else
			val->intval = POWER_SUPPLY_HEALTH_GOOD;

		break;

	default:
		return -EINVAL;
	}

	return 0;
}

static int sbs_check_state(struct sbs_info *chip)
{
	unsigned int reg;
	int ret;

	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &reg);
	if (!ret && reg != chip->last_state) {
		chip->last_state = reg;
		power_supply_changed(chip->power_supply);
		return 1;
	}

	return 0;
}

static void sbs_delayed_work(struct work_struct *work)
{
	struct sbs_info *chip = container_of(work, struct sbs_info, work.work);

	sbs_check_state(chip);

	schedule_delayed_work(&chip->work,
			      msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
}

static irqreturn_t sbs_irq_thread(int irq, void *data)
{
	struct sbs_info *chip = data;
	int ret;

	ret = sbs_check_state(chip);

	return ret ? IRQ_HANDLED : IRQ_NONE;
}

static enum power_supply_property sbs_properties[] = {
	POWER_SUPPLY_PROP_STATUS,
	POWER_SUPPLY_PROP_PRESENT,
	POWER_SUPPLY_PROP_ONLINE,
	POWER_SUPPLY_PROP_HEALTH,
};

static bool sbs_readable_reg(struct device *dev, unsigned int reg)
{
	return reg >= SBS_CHARGER_REG_SPEC_INFO;
}

static bool sbs_volatile_reg(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case SBS_CHARGER_REG_STATUS:
		return true;
	}

	return false;
}

static const struct regmap_config sbs_regmap = {
	.reg_bits	= 8,
	.val_bits	= 16,
	.max_register	= SBS_CHARGER_REG_ALARM_WARNING,
	.readable_reg	= sbs_readable_reg,
	.volatile_reg	= sbs_volatile_reg,
	.val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */
};

static const struct power_supply_desc sbs_desc = {
	.name = "sbs-charger",
	.type = POWER_SUPPLY_TYPE_MAINS,
	.properties = sbs_properties,
	.num_properties = ARRAY_SIZE(sbs_properties),
	.get_property = sbs_get_property,
};

static int sbs_probe(struct i2c_client *client)
{
	struct power_supply_config psy_cfg = {};
	struct sbs_info *chip;
	int ret, val;

	chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	chip->client = client;
	psy_cfg.of_node = client->dev.of_node;
	psy_cfg.drv_data = chip;

	i2c_set_clientdata(client, chip);

	chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap);
	if (IS_ERR(chip->regmap))
		return PTR_ERR(chip->regmap);

	/*
	 * Before we register, we need to make sure we can actually talk
	 * to the battery.
	 */
	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val);
	if (ret)
		return dev_err_probe(&client->dev, ret, "Failed to get device status\n");
	chip->last_state = val;

	chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, &psy_cfg);
	if (IS_ERR(chip->power_supply))
		return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply),
				     "Failed to register power supply\n");

	/*
	 * The sbs-charger spec doesn't impose the use of an interrupt. So in
	 * the case it wasn't provided we use polling in order get the charger's
	 * status.
	 */
	if (client->irq) {
		ret = devm_request_threaded_irq(&client->dev, client->irq,
					NULL, sbs_irq_thread,
					IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
					dev_name(&client->dev), chip);
		if (ret)
			return dev_err_probe(&client->dev, ret, "Failed to request irq\n");
	} else {
		ret = devm_delayed_work_autocancel(&client->dev, &chip->work,
						   sbs_delayed_work);
		if (ret)
			return dev_err_probe(&client->dev, ret,
					     "Failed to init work for polling\n");

		schedule_delayed_work(&chip->work,
				      msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
	}

	dev_info(&client->dev,
		 "%s: smart charger device registered\n", client->name);

	return 0;
}

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

static const struct i2c_device_id sbs_id[] = {
	{ "sbs-charger", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, sbs_id);

static struct i2c_driver sbs_driver = {
	.probe_new	= sbs_probe,
	.id_table	= sbs_id,
	.driver = {
		.name	= "sbs-charger",
		.of_match_table = of_match_ptr(sbs_dt_ids),
	},
};
module_i2c_driver(sbs_driver);

MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
MODULE_DESCRIPTION("SBS smart charger driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
feb583e3 NSJ	2	/*
	3	* Copyright (c) 2016, Prodys S.L.
	4	*
feb583e3 NSJ	5	* This adds support for sbs-charger compilant chips as defined here:
	6	* http://sbs-forum.org/specs/sbc110.pdf
	7	*
	8	* Implemetation based on sbs-battery.c
	9	*/
	10
	11	#include <linux/init.h>
	12	#include <linux/module.h>
	13	#include <linux/kernel.h>
	14	#include <linux/err.h>
	15	#include <linux/power_supply.h>
	16	#include <linux/i2c.h>
	17	#include <linux/slab.h>
	18	#include <linux/interrupt.h>
feb583e3	19	#include <linux/regmap.h>
feb583e3	20	#include <linux/bitops.h>
de85193c	21	#include <linux/devm-helpers.h>
feb583e3 NSJ	22
	23	#define SBS_CHARGER_REG_SPEC_INFO 0x11
	24	#define SBS_CHARGER_REG_STATUS 0x13
	25	#define SBS_CHARGER_REG_ALARM_WARNING 0x16
	26
a0921fc2	27	#define SBS_CHARGER_STATUS_CHARGE_INHIBITED BIT(0)
feb583e3 NSJ	28	#define SBS_CHARGER_STATUS_RES_COLD BIT(9)
	29	#define SBS_CHARGER_STATUS_RES_HOT BIT(10)
	30	#define SBS_CHARGER_STATUS_BATTERY_PRESENT BIT(14)
	31	#define SBS_CHARGER_STATUS_AC_PRESENT BIT(15)
	32
	33	#define SBS_CHARGER_POLL_TIME 500
	34
	35	struct sbs_info {
	36	struct i2c_client *client;
	37	struct power_supply *power_supply;
	38	struct regmap *regmap;
	39	struct delayed_work work;
	40	unsigned int last_state;
	41	};
	42
	43	static int sbs_get_property(struct power_supply *psy,
	44	enum power_supply_property psp,
	45	union power_supply_propval *val)
	46	{
	47	struct sbs_info *chip = power_supply_get_drvdata(psy);
	48	unsigned int reg;
	49
	50	reg = chip->last_state;
	51
	52	switch (psp) {
	53	case POWER_SUPPLY_PROP_PRESENT:
	54	val->intval = !!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT);
	55	break;
	56
	57	case POWER_SUPPLY_PROP_ONLINE:
	58	val->intval = !!(reg & SBS_CHARGER_STATUS_AC_PRESENT);
	59	break;
	60
	61	case POWER_SUPPLY_PROP_STATUS:
	62	val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
	63
	64	if (!(reg & SBS_CHARGER_STATUS_BATTERY_PRESENT))
	65	val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
	66	else if (reg & SBS_CHARGER_STATUS_AC_PRESENT &&
	67	!(reg & SBS_CHARGER_STATUS_CHARGE_INHIBITED))
	68	val->intval = POWER_SUPPLY_STATUS_CHARGING;
	69	else
	70	val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
	71
	72	break;
	73
	74	case POWER_SUPPLY_PROP_HEALTH:
	75	if (reg & SBS_CHARGER_STATUS_RES_COLD)
	76	val->intval = POWER_SUPPLY_HEALTH_COLD;
	77	if (reg & SBS_CHARGER_STATUS_RES_HOT)
	78	val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
	79	else
	80	val->intval = POWER_SUPPLY_HEALTH_GOOD;
	81
	82	break;
	83
	84	default:
	85	return -EINVAL;
	86	}
	87
	88	return 0;
	89	}
	90
	91	static int sbs_check_state(struct sbs_info *chip)
92	{
93	unsigned int reg;
94	int ret;
95
96	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &reg);
97	if (!ret && reg != chip->last_state) {
98	chip->last_state = reg;
99	power_supply_changed(chip->power_supply);
100	return 1;
101	}
102
103	return 0;
104	}
105
106	static void sbs_delayed_work(struct work_struct *work)
107	{
108	struct sbs_info *chip = container_of(work, struct sbs_info, work.work);
109
110	sbs_check_state(chip);
111
112	schedule_delayed_work(&chip->work,
113	msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
114	}
115
116	static irqreturn_t sbs_irq_thread(int irq, void *data)
117	{
118	struct sbs_info *chip = data;
119	int ret;
120
121	ret = sbs_check_state(chip);
122
123	return ret ? IRQ_HANDLED : IRQ_NONE;
124	}
125
126	static enum power_supply_property sbs_properties[] = {
127	POWER_SUPPLY_PROP_STATUS,
128	POWER_SUPPLY_PROP_PRESENT,
129	POWER_SUPPLY_PROP_ONLINE,
130	POWER_SUPPLY_PROP_HEALTH,
131	};
132
133	static bool sbs_readable_reg(struct device *dev, unsigned int reg)
134	{
dba83476	135	return reg >= SBS_CHARGER_REG_SPEC_INFO;
feb583e3 NSJ	136	}
	137
	138	static bool sbs_volatile_reg(struct device *dev, unsigned int reg)
	139	{
	140	switch (reg) {
	141	case SBS_CHARGER_REG_STATUS:
	142	return true;
	143	}
	144
	145	return false;
	146	}
	147
	148	static const struct regmap_config sbs_regmap = {
	149	.reg_bits = 8,
	150	.val_bits = 16,
	151	.max_register = SBS_CHARGER_REG_ALARM_WARNING,
	152	.readable_reg = sbs_readable_reg,
	153	.volatile_reg = sbs_volatile_reg,
	154	.val_format_endian = REGMAP_ENDIAN_LITTLE, /* since based on SMBus */
	155	};
	156
	157	static const struct power_supply_desc sbs_desc = {
	158	.name = "sbs-charger",
	159	.type = POWER_SUPPLY_TYPE_MAINS,
	160	.properties = sbs_properties,
	161	.num_properties = ARRAY_SIZE(sbs_properties),
	162	.get_property = sbs_get_property,
	163	};
	164
ef3f6e07	165	static int sbs_probe(struct i2c_client *client)
feb583e3 NSJ	166	{
	167	struct power_supply_config psy_cfg = {};
	168	struct sbs_info *chip;
	169	int ret, val;
	170
	171	chip = devm_kzalloc(&client->dev, sizeof(struct sbs_info), GFP_KERNEL);
	172	if (!chip)
	173	return -ENOMEM;
	174
	175	chip->client = client;
	176	psy_cfg.of_node = client->dev.of_node;
	177	psy_cfg.drv_data = chip;
	178
	179	i2c_set_clientdata(client, chip);
	180
	181	chip->regmap = devm_regmap_init_i2c(client, &sbs_regmap);
	182	if (IS_ERR(chip->regmap))
	183	return PTR_ERR(chip->regmap);
	184
	185	/*
	186	* Before we register, we need to make sure we can actually talk
	187	* to the battery.
	188	*/
	189	ret = regmap_read(chip->regmap, SBS_CHARGER_REG_STATUS, &val);
e319f4e2 SR	190	if (ret)
e319f4e2 SR	191	return dev_err_probe(&client->dev, ret, "Failed to get device status\n");
feb583e3 NSJ	192	chip->last_state = val;
feb583e3 NSJ	193
e319f4e2 SR	194	chip->power_supply = devm_power_supply_register(&client->dev, &sbs_desc, &psy_cfg);
	195	if (IS_ERR(chip->power_supply))
	196	return dev_err_probe(&client->dev, PTR_ERR(chip->power_supply),
	197	"Failed to register power supply\n");
feb583e3 NSJ	198
	199	/*
	200	* The sbs-charger spec doesn't impose the use of an interrupt. So in
	201	* the case it wasn't provided we use polling in order get the charger's
	202	* status.
	203	*/
	204	if (client->irq) {
	205	ret = devm_request_threaded_irq(&client->dev, client->irq,
	206	NULL, sbs_irq_thread,
	207	IRQF_TRIGGER_FALLING \| IRQF_ONESHOT,
	208	dev_name(&client->dev), chip);
e319f4e2 SR	209	if (ret)
e319f4e2 SR	210	return dev_err_probe(&client->dev, ret, "Failed to request irq\n");
feb583e3	211	} else {
de85193c CJ	212	ret = devm_delayed_work_autocancel(&client->dev, &chip->work,
	213	sbs_delayed_work);
	214	if (ret)
	215	return dev_err_probe(&client->dev, ret,
	216	"Failed to init work for polling\n");
	217
feb583e3 NSJ	218	schedule_delayed_work(&chip->work,
	219	msecs_to_jiffies(SBS_CHARGER_POLL_TIME));
	220	}
	221
	222	dev_info(&client->dev,
	223	"%s: smart charger device registered\n", client->name);
	224
	225	return 0;
	226	}
	227
feb583e3 NSJ	228	#ifdef CONFIG_OF
	229	static const struct of_device_id sbs_dt_ids[] = {
	230	{ .compatible = "sbs,sbs-charger" },
	231	{ },
	232	};
	233	MODULE_DEVICE_TABLE(of, sbs_dt_ids);
	234	#endif
	235
	236	static const struct i2c_device_id sbs_id[] = {
	237	{ "sbs-charger", 0 },
	238	{ }
	239	};
	240	MODULE_DEVICE_TABLE(i2c, sbs_id);
	241
	242	static struct i2c_driver sbs_driver = {
ef3f6e07	243	.probe_new = sbs_probe,
feb583e3 NSJ	244	.id_table = sbs_id,
	245	.driver = {
	246	.name = "sbs-charger",
	247	.of_match_table = of_match_ptr(sbs_dt_ids),
	248	},
	249	};
	250	module_i2c_driver(sbs_driver);
	251
	252	MODULE_AUTHOR("Nicolas Saenz Julienne <nicolassaenzj@gmail.com>");
	253	MODULE_DESCRIPTION("SBS smart charger driver");
	254	MODULE_LICENSE("GPL v2");