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 
52 enum 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 
65 static 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 
79 struct 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 
max14656_read_reg(struct i2c_client * client,int reg,u8 * val)89 static 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 
max14656_write_reg(struct i2c_client * client,int reg,u8 val)104 static 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 
max14656_read_block_reg(struct i2c_client * client,u8 reg,u8 length,u8 * val)118 static 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
max14656_irq_worker(struct work_struct * work)134 static 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 
max14656_irq(int irq,void * dev_id)161 static 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 
max14656_hw_init(struct max14656_chip * chip)170 static 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 
max14656_get_property(struct power_supply * psy,enum power_supply_property psp,union power_supply_propval * val)208 static 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 
231 static 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 
max14656_probe(struct i2c_client * client)237 static 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 
302 static const struct i2c_device_id max14656_id[] = {
303 	{ "max14656", 0 },
304 	{}
305 };
306 MODULE_DEVICE_TABLE(i2c, max14656_id);
307 
308 static const struct of_device_id max14656_match_table[] = {
309 	{ .compatible = "maxim,max14656", },
310 	{}
311 };
312 MODULE_DEVICE_TABLE(of, max14656_match_table);
313 
314 static 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 };
322 module_i2c_driver(max14656_i2c_driver);
323 
324 MODULE_DESCRIPTION("MAX14656 USB charger detector");
325 MODULE_LICENSE("GPL v2");
326