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, command: 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, command: reg, value: 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, command: reg, length, values: 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(client: chip->client, MAX14656_DEVICE_ID,
143 REG_TOTAL_NUM, val: 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(psy: 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(dwork: &chip->irq_work, delay: msecs_to_jiffies(m: 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: &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, val: 0x3))
199 return -EINVAL;
200
201 if (max14656_write_reg(client, MAX14656_INTMASK_2, val: 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(adap: 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, size: 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(parent: dev,
275 desc: &chip->psy_desc, cfg: &psy_cfg);
276 if (IS_ERR(ptr: chip->detect_psy)) {
277 dev_err(dev, "power_supply_register failed\n");
278 return -EINVAL;
279 }
280
281 ret = devm_delayed_work_autocancel(dev, w: &chip->irq_work,
282 worker: 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, irq: chip->irq, handler: max14656_irq,
289 IRQF_TRIGGER_FALLING,
290 MAX14656_NAME, dev_id: chip);
291 if (ret) {
292 dev_err(dev, "request_irq %d failed\n", chip->irq);
293 return -EINVAL;
294 }
295 enable_irq_wake(irq: chip->irq);
296
297 schedule_delayed_work(dwork: &chip->irq_work, delay: msecs_to_jiffies(m: 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

source code of linux/drivers/power/supply/max14656_charger_detector.c