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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/of_device.h>
19#include <linux/workqueue.h>
20#include <linux/power_supply.h>
21
22#define MAX14656_MANUFACTURER "Maxim Integrated"
23#define MAX14656_NAME "max14656"
24
25#define MAX14656_DEVICE_ID 0x00
26#define MAX14656_INTERRUPT_1 0x01
27#define MAX14656_INTERRUPT_2 0x02
28#define MAX14656_STATUS_1 0x03
29#define MAX14656_STATUS_2 0x04
30#define MAX14656_INTMASK_1 0x05
31#define MAX14656_INTMASK_2 0x06
32#define MAX14656_CONTROL_1 0x07
33#define MAX14656_CONTROL_2 0x08
34#define MAX14656_CONTROL_3 0x09
35
36#define DEVICE_VENDOR_MASK 0xf0
37#define DEVICE_REV_MASK 0x0f
38#define INT_EN_REG_MASK BIT(4)
39#define CHG_TYPE_INT_MASK BIT(0)
40#define STATUS1_VB_VALID_MASK BIT(4)
41#define STATUS1_CHG_TYPE_MASK 0xf
42#define INT1_DCD_TIMEOUT_MASK BIT(7)
43#define CONTROL1_DEFAULT 0x0d
44#define CONTROL1_INT_EN BIT(4)
45#define CONTROL1_INT_ACTIVE_HIGH BIT(5)
46#define CONTROL1_EDGE BIT(7)
47#define CONTROL2_DEFAULT 0x8e
48#define CONTROL2_ADC_EN BIT(0)
49#define CONTROL3_DEFAULT 0x8d
50
51enum max14656_chg_type {
52 MAX14656_NO_CHARGER = 0,
53 MAX14656_SDP_CHARGER,
54 MAX14656_CDP_CHARGER,
55 MAX14656_DCP_CHARGER,
56 MAX14656_APPLE_500MA_CHARGER,
57 MAX14656_APPLE_1A_CHARGER,
58 MAX14656_APPLE_2A_CHARGER,
59 MAX14656_SPECIAL_500MA_CHARGER,
60 MAX14656_APPLE_12W,
61 MAX14656_CHARGER_LAST
62};
63
64static const struct max14656_chg_type_props {
65 enum power_supply_type type;
66} chg_type_props[] = {
67 { POWER_SUPPLY_TYPE_UNKNOWN },
68 { POWER_SUPPLY_TYPE_USB },
69 { POWER_SUPPLY_TYPE_USB_CDP },
70 { POWER_SUPPLY_TYPE_USB_DCP },
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 },
76};
77
78struct max14656_chip {
79 struct i2c_client *client;
80 struct power_supply *detect_psy;
81 struct power_supply_desc psy_desc;
82 struct delayed_work irq_work;
83
84 int irq;
85 int online;
86};
87
88static int max14656_read_reg(struct i2c_client *client, int reg, u8 *val)
89{
90 s32 ret;
91
92 ret = i2c_smbus_read_byte_data(client, reg);
93 if (ret < 0) {
94 dev_err(&client->dev,
95 "i2c read fail: can't read from %02x: %d\n",
96 reg, ret);
97 return ret;
98 }
99 *val = ret;
100 return 0;
101}
102
103static int max14656_write_reg(struct i2c_client *client, int reg, u8 val)
104{
105 s32 ret;
106
107 ret = i2c_smbus_write_byte_data(client, reg, val);
108 if (ret < 0) {
109 dev_err(&client->dev,
110 "i2c write fail: can't write %02x to %02x: %d\n",
111 val, reg, ret);
112 return ret;
113 }
114 return 0;
115}
116
117static int max14656_read_block_reg(struct i2c_client *client, u8 reg,
118 u8 length, u8 *val)
119{
120 int ret;
121
122 ret = i2c_smbus_read_i2c_block_data(client, reg, length, val);
123 if (ret < 0) {
124 dev_err(&client->dev, "failed to block read reg 0x%x: %d\n",
125 reg, ret);
126 return ret;
127 }
128
129 return 0;
130}
131
132#define REG_TOTAL_NUM 5
133static void max14656_irq_worker(struct work_struct *work)
134{
135 struct max14656_chip *chip =
136 container_of(work, struct max14656_chip, irq_work.work);
137
138 u8 buf[REG_TOTAL_NUM];
139 u8 chg_type;
140
141 max14656_read_block_reg(chip->client, MAX14656_DEVICE_ID,
142 REG_TOTAL_NUM, buf);
143
144 if ((buf[MAX14656_STATUS_1] & STATUS1_VB_VALID_MASK) &&
145 (buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK)) {
146 chg_type = buf[MAX14656_STATUS_1] & STATUS1_CHG_TYPE_MASK;
147 if (chg_type < MAX14656_CHARGER_LAST)
148 chip->psy_desc.type = chg_type_props[chg_type].type;
149 else
150 chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
151 chip->online = 1;
152 } else {
153 chip->online = 0;
154 chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
155 }
156
157 power_supply_changed(chip->detect_psy);
158}
159
160static irqreturn_t max14656_irq(int irq, void *dev_id)
161{
162 struct max14656_chip *chip = dev_id;
163
164 schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(100));
165
166 return IRQ_HANDLED;
167}
168
169static int max14656_hw_init(struct max14656_chip *chip)
170{
171 uint8_t val = 0;
172 uint8_t rev;
173 struct i2c_client *client = chip->client;
174
175 if (max14656_read_reg(client, MAX14656_DEVICE_ID, &val))
176 return -ENODEV;
177
178 if ((val & DEVICE_VENDOR_MASK) != 0x20) {
179 dev_err(&client->dev, "wrong vendor ID %d\n",
180 ((val & DEVICE_VENDOR_MASK) >> 4));
181 return -ENODEV;
182 }
183 rev = val & DEVICE_REV_MASK;
184
185
186 if (max14656_write_reg(client, MAX14656_CONTROL_2, CONTROL2_ADC_EN))
187 return -EINVAL;
188
189
190 if (max14656_write_reg(client, MAX14656_CONTROL_1,
191 CONTROL1_DEFAULT |
192 CONTROL1_INT_EN |
193 CONTROL1_INT_ACTIVE_HIGH |
194 CONTROL1_EDGE))
195 return -EINVAL;
196
197 if (max14656_write_reg(client, MAX14656_INTMASK_1, 0x3))
198 return -EINVAL;
199
200 if (max14656_write_reg(client, MAX14656_INTMASK_2, 0x1))
201 return -EINVAL;
202
203 dev_info(&client->dev, "detected revision %d\n", rev);
204 return 0;
205}
206
207static int max14656_get_property(struct power_supply *psy,
208 enum power_supply_property psp,
209 union power_supply_propval *val)
210{
211 struct max14656_chip *chip = power_supply_get_drvdata(psy);
212
213 switch (psp) {
214 case POWER_SUPPLY_PROP_ONLINE:
215 val->intval = chip->online;
216 break;
217 case POWER_SUPPLY_PROP_MODEL_NAME:
218 val->strval = MAX14656_NAME;
219 break;
220 case POWER_SUPPLY_PROP_MANUFACTURER:
221 val->strval = MAX14656_MANUFACTURER;
222 break;
223 default:
224 return -EINVAL;
225 }
226
227 return 0;
228}
229
230static enum power_supply_property max14656_battery_props[] = {
231 POWER_SUPPLY_PROP_ONLINE,
232 POWER_SUPPLY_PROP_MODEL_NAME,
233 POWER_SUPPLY_PROP_MANUFACTURER,
234};
235
236static void stop_irq_work(void *data)
237{
238 struct max14656_chip *chip = data;
239
240 cancel_delayed_work_sync(&chip->irq_work);
241}
242
243
244static int max14656_probe(struct i2c_client *client,
245 const struct i2c_device_id *id)
246{
247 struct i2c_adapter *adapter = client->adapter;
248 struct device *dev = &client->dev;
249 struct power_supply_config psy_cfg = {};
250 struct max14656_chip *chip;
251 int irq = client->irq;
252 int ret = 0;
253
254 if (irq <= 0) {
255 dev_err(dev, "invalid irq number: %d\n", irq);
256 return -ENODEV;
257 }
258
259 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) {
260 dev_err(dev, "No support for SMBUS_BYTE_DATA\n");
261 return -ENODEV;
262 }
263
264 chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
265 if (!chip)
266 return -ENOMEM;
267
268 psy_cfg.drv_data = chip;
269 chip->client = client;
270 chip->online = 0;
271 chip->psy_desc.name = MAX14656_NAME;
272 chip->psy_desc.type = POWER_SUPPLY_TYPE_UNKNOWN;
273 chip->psy_desc.properties = max14656_battery_props;
274 chip->psy_desc.num_properties = ARRAY_SIZE(max14656_battery_props);
275 chip->psy_desc.get_property = max14656_get_property;
276 chip->irq = irq;
277
278 ret = max14656_hw_init(chip);
279 if (ret)
280 return -ENODEV;
281
282 chip->detect_psy = devm_power_supply_register(dev,
283 &chip->psy_desc, &psy_cfg);
284 if (IS_ERR(chip->detect_psy)) {
285 dev_err(dev, "power_supply_register failed\n");
286 return -EINVAL;
287 }
288
289 INIT_DELAYED_WORK(&chip->irq_work, max14656_irq_worker);
290 ret = devm_add_action(dev, stop_irq_work, chip);
291 if (ret) {
292 dev_err(dev, "devm_add_action %d failed\n", ret);
293 return ret;
294 }
295
296 ret = devm_request_irq(dev, chip->irq, max14656_irq,
297 IRQF_TRIGGER_FALLING,
298 MAX14656_NAME, chip);
299 if (ret) {
300 dev_err(dev, "request_irq %d failed\n", chip->irq);
301 return -EINVAL;
302 }
303 enable_irq_wake(chip->irq);
304
305 schedule_delayed_work(&chip->irq_work, msecs_to_jiffies(2000));
306
307 return 0;
308}
309
310static const struct i2c_device_id max14656_id[] = {
311 { "max14656", 0 },
312 {}
313};
314MODULE_DEVICE_TABLE(i2c, max14656_id);
315
316static const struct of_device_id max14656_match_table[] = {
317 { .compatible = "maxim,max14656", },
318 {}
319};
320MODULE_DEVICE_TABLE(of, max14656_match_table);
321
322static struct i2c_driver max14656_i2c_driver = {
323 .driver = {
324 .name = "max14656",
325 .of_match_table = max14656_match_table,
326 },
327 .probe = max14656_probe,
328 .id_table = max14656_id,
329};
330module_i2c_driver(max14656_i2c_driver);
331
332MODULE_DESCRIPTION("MAX14656 USB charger detector");
333MODULE_LICENSE("GPL v2");
334
