1/*
2 *  max17040_battery.c
3 *  fuel-gauge systems for lithium-ion (Li+) batteries
4 *
5 *  Copyright (C) 2009 Samsung Electronics
6 *  Minkyu Kang <mk7.kang@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/platform_device.h>
16#include <linux/mutex.h>
17#include <linux/err.h>
18#include <linux/i2c.h>
19#include <linux/delay.h>
20#include <linux/power_supply.h>
21#include <linux/max17040_battery.h>
22#include <linux/slab.h>
23
24#define MAX17040_VCELL_MSB	0x02
25#define MAX17040_VCELL_LSB	0x03
26#define MAX17040_SOC_MSB	0x04
27#define MAX17040_SOC_LSB	0x05
28#define MAX17040_MODE_MSB	0x06
29#define MAX17040_MODE_LSB	0x07
30#define MAX17040_VER_MSB	0x08
31#define MAX17040_VER_LSB	0x09
32#define MAX17040_RCOMP_MSB	0x0C
33#define MAX17040_RCOMP_LSB	0x0D
34#define MAX17040_CMD_MSB	0xFE
35#define MAX17040_CMD_LSB	0xFF
36
37#define MAX17040_DELAY		1000
38#define MAX17040_BATTERY_FULL	95
39
40struct max17040_chip {
41	struct i2c_client		*client;
42	struct delayed_work		work;
43	struct power_supply		*battery;
44	struct max17040_platform_data	*pdata;
45
46	/* State Of Connect */
47	int online;
48	/* battery voltage */
49	int vcell;
50	/* battery capacity */
51	int soc;
52	/* State Of Charge */
53	int status;
54};
55
56static int max17040_get_property(struct power_supply *psy,
57			    enum power_supply_property psp,
58			    union power_supply_propval *val)
59{
60	struct max17040_chip *chip = power_supply_get_drvdata(psy);
61
62	switch (psp) {
63	case POWER_SUPPLY_PROP_STATUS:
64		val->intval = chip->status;
65		break;
66	case POWER_SUPPLY_PROP_ONLINE:
67		val->intval = chip->online;
68		break;
69	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
70		val->intval = chip->vcell;
71		break;
72	case POWER_SUPPLY_PROP_CAPACITY:
73		val->intval = chip->soc;
74		break;
75	default:
76		return -EINVAL;
77	}
78	return 0;
79}
80
81static int max17040_write_reg(struct i2c_client *client, int reg, u8 value)
82{
83	int ret;
84
85	ret = i2c_smbus_write_byte_data(client, reg, value);
86
87	if (ret < 0)
88		dev_err(&client->dev, "%s: err %d\n", __func__, ret);
89
90	return ret;
91}
92
93static int max17040_read_reg(struct i2c_client *client, int reg)
94{
95	int ret;
96
97	ret = i2c_smbus_read_byte_data(client, reg);
98
99	if (ret < 0)
100		dev_err(&client->dev, "%s: err %d\n", __func__, ret);
101
102	return ret;
103}
104
105static void max17040_reset(struct i2c_client *client)
106{
107	max17040_write_reg(client, MAX17040_CMD_MSB, 0x54);
108	max17040_write_reg(client, MAX17040_CMD_LSB, 0x00);
109}
110
111static void max17040_get_vcell(struct i2c_client *client)
112{
113	struct max17040_chip *chip = i2c_get_clientdata(client);
114	u8 msb;
115	u8 lsb;
116
117	msb = max17040_read_reg(client, MAX17040_VCELL_MSB);
118	lsb = max17040_read_reg(client, MAX17040_VCELL_LSB);
119
120	chip->vcell = (msb << 4) + (lsb >> 4);
121}
122
123static void max17040_get_soc(struct i2c_client *client)
124{
125	struct max17040_chip *chip = i2c_get_clientdata(client);
126	u8 msb;
127	u8 lsb;
128
129	msb = max17040_read_reg(client, MAX17040_SOC_MSB);
130	lsb = max17040_read_reg(client, MAX17040_SOC_LSB);
131
132	chip->soc = msb;
133}
134
135static void max17040_get_version(struct i2c_client *client)
136{
137	u8 msb;
138	u8 lsb;
139
140	msb = max17040_read_reg(client, MAX17040_VER_MSB);
141	lsb = max17040_read_reg(client, MAX17040_VER_LSB);
142
143	dev_info(&client->dev, "MAX17040 Fuel-Gauge Ver %d%d\n", msb, lsb);
144}
145
146static void max17040_get_online(struct i2c_client *client)
147{
148	struct max17040_chip *chip = i2c_get_clientdata(client);
149
150	if (chip->pdata && chip->pdata->battery_online)
151		chip->online = chip->pdata->battery_online();
152	else
153		chip->online = 1;
154}
155
156static void max17040_get_status(struct i2c_client *client)
157{
158	struct max17040_chip *chip = i2c_get_clientdata(client);
159
160	if (!chip->pdata || !chip->pdata->charger_online
161			|| !chip->pdata->charger_enable) {
162		chip->status = POWER_SUPPLY_STATUS_UNKNOWN;
163		return;
164	}
165
166	if (chip->pdata->charger_online()) {
167		if (chip->pdata->charger_enable())
168			chip->status = POWER_SUPPLY_STATUS_CHARGING;
169		else
170			chip->status = POWER_SUPPLY_STATUS_NOT_CHARGING;
171	} else {
172		chip->status = POWER_SUPPLY_STATUS_DISCHARGING;
173	}
174
175	if (chip->soc > MAX17040_BATTERY_FULL)
176		chip->status = POWER_SUPPLY_STATUS_FULL;
177}
178
179static void max17040_work(struct work_struct *work)
180{
181	struct max17040_chip *chip;
182
183	chip = container_of(work, struct max17040_chip, work.work);
184
185	max17040_get_vcell(chip->client);
186	max17040_get_soc(chip->client);
187	max17040_get_online(chip->client);
188	max17040_get_status(chip->client);
189
190	queue_delayed_work(system_power_efficient_wq, &chip->work,
191			   MAX17040_DELAY);
192}
193
194static enum power_supply_property max17040_battery_props[] = {
195	POWER_SUPPLY_PROP_STATUS,
196	POWER_SUPPLY_PROP_ONLINE,
197	POWER_SUPPLY_PROP_VOLTAGE_NOW,
198	POWER_SUPPLY_PROP_CAPACITY,
199};
200
201static const struct power_supply_desc max17040_battery_desc = {
202	.name		= "battery",
203	.type		= POWER_SUPPLY_TYPE_BATTERY,
204	.get_property	= max17040_get_property,
205	.properties	= max17040_battery_props,
206	.num_properties	= ARRAY_SIZE(max17040_battery_props),
207};
208
209static int max17040_probe(struct i2c_client *client,
210			const struct i2c_device_id *id)
211{
212	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
213	struct power_supply_config psy_cfg = {};
214	struct max17040_chip *chip;
215
216	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE))
217		return -EIO;
218
219	chip = devm_kzalloc(&client->dev, sizeof(*chip), GFP_KERNEL);
220	if (!chip)
221		return -ENOMEM;
222
223	chip->client = client;
224	chip->pdata = client->dev.platform_data;
225
226	i2c_set_clientdata(client, chip);
227	psy_cfg.drv_data = chip;
228
229	chip->battery = power_supply_register(&client->dev,
230				&max17040_battery_desc, &psy_cfg);
231	if (IS_ERR(chip->battery)) {
232		dev_err(&client->dev, "failed: power supply register\n");
233		return PTR_ERR(chip->battery);
234	}
235
236	max17040_reset(client);
237	max17040_get_version(client);
238
239	INIT_DEFERRABLE_WORK(&chip->work, max17040_work);
240	queue_delayed_work(system_power_efficient_wq, &chip->work,
241			   MAX17040_DELAY);
242
243	return 0;
244}
245
246static int max17040_remove(struct i2c_client *client)
247{
248	struct max17040_chip *chip = i2c_get_clientdata(client);
249
250	power_supply_unregister(chip->battery);
251	cancel_delayed_work(&chip->work);
252	return 0;
253}
254
255#ifdef CONFIG_PM_SLEEP
256
257static int max17040_suspend(struct device *dev)
258{
259	struct i2c_client *client = to_i2c_client(dev);
260	struct max17040_chip *chip = i2c_get_clientdata(client);
261
262	cancel_delayed_work(&chip->work);
263	return 0;
264}
265
266static int max17040_resume(struct device *dev)
267{
268	struct i2c_client *client = to_i2c_client(dev);
269	struct max17040_chip *chip = i2c_get_clientdata(client);
270
271	queue_delayed_work(system_power_efficient_wq, &chip->work,
272			   MAX17040_DELAY);
273	return 0;
274}
275
276static SIMPLE_DEV_PM_OPS(max17040_pm_ops, max17040_suspend, max17040_resume);
277#define MAX17040_PM_OPS (&max17040_pm_ops)
278
279#else
280
281#define MAX17040_PM_OPS NULL
282
283#endif /* CONFIG_PM_SLEEP */
284
285static const struct i2c_device_id max17040_id[] = {
286	{ "max17040" },
287	{ "max77836-battery" },
288	{ }
289};
290MODULE_DEVICE_TABLE(i2c, max17040_id);
291
292static struct i2c_driver max17040_i2c_driver = {
293	.driver	= {
294		.name	= "max17040",
295		.pm	= MAX17040_PM_OPS,
296	},
297	.probe		= max17040_probe,
298	.remove		= max17040_remove,
299	.id_table	= max17040_id,
300};
301module_i2c_driver(max17040_i2c_driver);
302
303MODULE_AUTHOR("Minkyu Kang <mk7.kang@samsung.com>");
304MODULE_DESCRIPTION("MAX17040 Fuel Gauge");
305MODULE_LICENSE("GPL");
306