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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
188 if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
189 return -EINVAL;
190
191
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
