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" },
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