summaryrefslogtreecommitdiffstats
path: root/drivers/power/supply/sbs-charger.c
blob: 36a048d687e0646bc3f2a7ad3302104a7422aa5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
// 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/gpio.h>
#include <linux/regmap.h>
#include <linux/of_gpio.h>
#include <linux/bitops.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(1)
#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,
		     const struct i2c_device_id *id)
{
	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 {
		INIT_DELAYED_WORK(&chip->work, sbs_delayed_work);
		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;
}

static int sbs_remove(struct i2c_client *client)
{
	struct sbs_info *chip = i2c_get_clientdata(client);

	cancel_delayed_work_sync(&chip->work);

	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		= sbs_probe,
	.remove		= sbs_remove,
	.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");