1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Maxim MAX14656 / AL32 USB Charger Detector driver
4 *
5 * Copyright (C) 2014 LG Electronics, Inc
6 * Copyright (C) 2016 Alexander Kurz <akurz@blala.de>
7 *
8 * Components from Maxim AL32 Charger detection Driver for MX50 Yoshi Board
9 * Copyright (C) Amazon Technologies Inc. All rights reserved.
10 * Manish Lachwani (lachwani@lab126.com)
11 */
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/delay.h>
15#include <linux/i2c.h>
16#include <linux/interrupt.h>
17#include <linux/slab.h>
18#include <linux/gpio.h>
19#include <linux/of_gpio.h>
20#include <linux/of_device.h>
21#include <linux/workqueue.h>
22#include <linux/power_supply.h>
23
24#define MAX14656_MANUFACTURER	"Maxim Integrated"
25#define MAX14656_NAME		"max14656"
26
27#define MAX14656_DEVICE_ID	0x00
28#define MAX14656_INTERRUPT_1	0x01
29#define MAX14656_INTERRUPT_2	0x02
30#define MAX14656_STATUS_1	0x03
31#define MAX14656_STATUS_2	0x04
32#define MAX14656_INTMASK_1	0x05
33#define MAX14656_INTMASK_2	0x06
34#define MAX14656_CONTROL_1	0x07
35#define MAX14656_CONTROL_2	0x08
36#define MAX14656_CONTROL_3	0x09
37
38#define DEVICE_VENDOR_MASK	0xf0
39#define DEVICE_REV_MASK		0x0f
40#define INT_EN_REG_MASK		BIT(4)
41#define CHG_TYPE_INT_MASK	BIT(0)
42#define STATUS1_VB_VALID_MASK	BIT(4)
43#define STATUS1_CHG_TYPE_MASK	0xf
44#define INT1_DCD_TIMEOUT_MASK	BIT(7)
45#define CONTROL1_DEFAULT	0x0d
46#define CONTROL1_INT_EN		BIT(4)
47#define CONTROL1_INT_ACTIVE_HIGH	BIT(5)
48#define CONTROL1_EDGE		BIT(7)
49#define CONTROL2_DEFAULT	0x8e
50#define CONTROL2_ADC_EN		BIT(0)
51#define CONTROL3_DEFAULT	0x8d
52
53enum max14656_chg_type {
54	MAX14656_NO_CHARGER	= 0,
55	MAX14656_SDP_CHARGER,
56	MAX14656_CDP_CHARGER,
57	MAX14656_DCP_CHARGER,
58	MAX14656_APPLE_500MA_CHARGER,
59	MAX14656_APPLE_1A_CHARGER,
60	MAX14656_APPLE_2A_CHARGER,
61	MAX14656_SPECIAL_500MA_CHARGER,
62	MAX14656_APPLE_12W,
63	MAX14656_CHARGER_LAST
64};
65
66static const struct max14656_chg_type_props {
67	enum power_supply_type type;
68} chg_type_props[] = {
69	{ POWER_SUPPLY_TYPE_UNKNOWN },
70	{ POWER_SUPPLY_TYPE_USB },
71	{ POWER_SUPPLY_TYPE_USB_CDP },
72	{ POWER_SUPPLY_TYPE_USB_DCP },
73	{ POWER_SUPPLY_TYPE_USB_DCP },
74	{ POWER_SUPPLY_TYPE_USB_DCP },
75	{ POWER_SUPPLY_TYPE_USB_DCP },
76	{ POWER_SUPPLY_TYPE_USB_DCP },
77	{ POWER_SUPPLY_TYPE_USB },
78};
79
80struct max14656_chip {
81	struct i2c_client	*client;
82	struct power_supply	*detect_psy;
83	struct power_supply_desc psy_desc;
84	struct delayed_work	irq_work;
85
86	int irq;
87	int online;
88};
89
90static int max14656_read_reg(struct i2c_client *client, int reg, u8 *val)
91{
92	s32 ret;
93
94	ret = i2c_smbus_read_byte_data(client, reg);
95	if (ret < 0) {
96		dev_err(&client->dev,
97			"i2c read fail: can't read from %02x: %d\n",
98			reg, ret);
99		return ret;
100	}
101	*val = ret;
102	return 0;
103}
104
105static int max14656_write_reg(struct i2c_client *client, int reg, u8 val)
106{
107	s32 ret;
108
109	ret = i2c_smbus_write_byte_data(client, reg, val);
110	if (ret < 0) {
111		dev_err(&client->dev,
112			"i2c write fail: can't write %02x to %02x: %d\n",
113			val, reg, ret);
114		return ret;
115	}
116	return 0;
117}
118
119static int max14656_read_block_reg(struct i2c_client *client, u8 reg,
120				  u8 length, u8 *val)
121{
122	int ret;
123
124	ret = i2c_smbus_read_i2c_block_data(client, reg, length, val);
125	if (ret < 0) {
126		dev_err(&client->dev, "failed to block read reg 0x%x: %d\n",
127				reg, ret);
128		return ret;
129	}
130
131	return 0;
132}
133
134#define        REG_TOTAL_NUM   5
135static void max14656_irq_worker(struct work_struct *work)
136{
137	struct max14656_chip *chip =
138		container_of(work, struct max14656_chip, irq_work.work);
139
140	u8 buf[REG_TOTAL_NUM];
141	u8 chg_type;
142
143	max14656_read_block_reg(chip->client, MAX14656_DEVICE_ID,
144				REG_TOTAL_NUM, buf);
145
146	if ((buf[MAX14656_STATUS_1] & STATUS1_VB_VALID_MASK) &&
147		(buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK)) {
148		chg_type = buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK;
149		if (chg_type < MAX14656_CHARGER_LAST)
150			chip->psy_desc.type = chg_type_props[chg_type].type;
151		else
152			chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
153		chip->online = 1;
154	} else {
155		chip->online = 0;
156		chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
157	}
158
159	power_supply_changed(chip->detect_psy);
160}
161
162static irqreturn_t max14656_irq(int irq, void *dev_id)
163{
164	struct max14656_chip *chip = dev_id;
165
166	schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(100));
167
168	return IRQ_HANDLED;
169}
170
171static int max14656_hw_init(struct max14656_chip *chip)
172{
173	uint8_t val = 0;
174	uint8_t rev;
175	struct i2c_client *client = chip->client;
176
177	if (max14656_read_reg(client, MAX14656_DEVICE_ID, &val))
178		return -ENODEV;
179
180	if ((val & DEVICE_VENDOR_MASK) != 0x20) {
181		dev_err(&client->dev, "wrong vendor ID %d\n",
182			((val & DEVICE_VENDOR_MASK) >> 4));
183		return -ENODEV;
184	}
185	rev = val & DEVICE_REV_MASK;
186
187	/* Turn on ADC_EN */
188	if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
189		return -EINVAL;
190
191	/* turn on interrupts and low power mode */
192	if (max14656_write_reg(client, MAX14656_CONTROL_1,
193		CONTROL1_DEFAULT |
194		CONTROL1_INT_EN |
195		CONTROL1_INT_ACTIVE_HIGH |
196		CONTROL1_EDGE))
197		return -EINVAL;
198
199	if (max14656_write_reg(client, MAX14656_INTMASK_1, 0x3))
200		return -EINVAL;
201
202	if (max14656_write_reg(client, MAX14656_INTMASK_2, 0x1))
203		return -EINVAL;
204
205	dev_info(&client->dev, "detected revision %d\n", rev);
206	return 0;
207}
208
209static int max14656_get_property(struct power_supply *psy,
210			    enum power_supply_property psp,
211			    union power_supply_propval *val)
212{
213	struct max14656_chip *chip = power_supply_get_drvdata(psy);
214
215	switch (psp) {
216	case POWER_SUPPLY_PROP_ONLINE:
217		val->intval = chip->online;
218		break;
219	case POWER_SUPPLY_PROP_MODEL_NAME:
220		val->strval = MAX14656_NAME;
221		break;
222	case POWER_SUPPLY_PROP_MANUFACTURER:
223		val->strval = MAX14656_MANUFACTURER;
224		break;
225	default:
226		return -EINVAL;
227	}
228
229	return 0;
230}
231
232static enum power_supply_property max14656_battery_props[] = {
233	POWER_SUPPLY_PROP_ONLINE,
234	POWER_SUPPLY_PROP_MODEL_NAME,
235	POWER_SUPPLY_PROP_MANUFACTURER,
236};
237
238static void stop_irq_work(void *data)
239{
240	struct max14656_chip *chip = data;
241
242	cancel_delayed_work_sync(&chip->irq_work);
243}
244
245
246static int max14656_probe(struct i2c_client *client,
247			  const struct i2c_device_id *id)
248{
249	struct i2c_adapter *adapter = client->adapter;
250	struct device *dev = &client->dev;
251	struct power_supply_config psy_cfg = {};
252	struct max14656_chip *chip;
253	int irq = client->irq;
254	int ret = 0;
255
256	if (irq <= 0) {
257		dev_err(dev, "invalid irq number: %d\n", irq);
258		return -ENODEV;
259	}
260
261	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
262		dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
263		return -ENODEV;
264	}
265
266	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
267	if (!chip)
268		return -ENOMEM;
269
270	psy_cfg.drv_data = chip;
271	chip->client = client;
272	chip->online = 0;
273	chip->psy_desc.name = MAX14656_NAME;
274	chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
275	chip->psy_desc.properties = max14656_battery_props;
276	chip->psy_desc.num_properties = ARRAY_SIZE(max14656_battery_props);
277	chip->psy_desc.get_property = max14656_get_property;
278	chip->irq = irq;
279
280	ret = max14656_hw_init(chip);
281	if (ret)
282		return -ENODEV;
283
284	chip->detect_psy = devm_power_supply_register(dev,
285		       &chip->psy_desc, &psy_cfg);
286	if (IS_ERR(chip->detect_psy)) {
287		dev_err(dev, "power_supply_register failed\n");
288		return -EINVAL;
289	}
290
291	INIT_DELAYED_WORK(&chip->irq_work, max14656_irq_worker);
292	ret = devm_add_action(dev, stop_irq_work, chip);
293	if (ret) {
294		dev_err(dev, "devm_add_action %d failed\n", ret);
295		return ret;
296	}
297
298	ret = devm_request_irq(dev, chip->irq, max14656_irq,
299			       IRQF_TRIGGER_FALLING,
300			       MAX14656_NAME, chip);
301	if (ret) {
302		dev_err(dev, "request_irq %d failed\n", chip->irq);
303		return -EINVAL;
304	}
305	enable_irq_wake(chip->irq);
306
307	schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
308
309	return 0;
310}
311
312static const struct i2c_device_id max14656_id[] = {
313	{ "max14656", 0 },
314	{}
315};
316MODULE_DEVICE_TABLE(i2c, max14656_id);
317
318static const struct of_device_id max14656_match_table[] = {
319	{ .compatible = "maxim,max14656", },
320	{}
321};
322MODULE_DEVICE_TABLE(of, max14656_match_table);
323
324static struct i2c_driver max14656_i2c_driver = {
325	.driver = {
326		.name	= "max14656",
327		.of_match_table = max14656_match_table,
328	},
329	.probe		= max14656_probe,
330	.id_table	= max14656_id,
331};
332module_i2c_driver(max14656_i2c_driver);
333
334MODULE_DESCRIPTION("MAX14656 USB charger detector");
335MODULE_LICENSE("GPL v2");
336