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