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f7c2fe38 FL |
1 | /* |
2 | * Driver for Texas Instruments INA219, INA226 power monitor chips | |
3 | * | |
4 | * INA219: | |
5 | * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface | |
6 | * Datasheet: http://www.ti.com/product/ina219 | |
7 | * | |
8 | * INA226: | |
9 | * Bi-Directional Current/Power Monitor with I2C Interface | |
10 | * Datasheet: http://www.ti.com/product/ina226 | |
11 | * | |
12 | * Copyright (C) 2012 Lothar Felten <l-felten@ti.com> | |
13 | * Thanks to Jan Volkering | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or modify | |
16 | * it under the terms of the GNU General Public License as published by | |
17 | * the Free Software Foundation; version 2 of the License. | |
18 | */ | |
19 | ||
20 | #include <linux/kernel.h> | |
21 | #include <linux/module.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/err.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/i2c.h> | |
26 | #include <linux/hwmon.h> | |
27 | #include <linux/hwmon-sysfs.h> | |
28 | ||
29 | #include <linux/platform_data/ina2xx.h> | |
30 | ||
31 | /* common register definitions */ | |
32 | #define INA2XX_CONFIG 0x00 | |
33 | #define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */ | |
34 | #define INA2XX_BUS_VOLTAGE 0x02 /* readonly */ | |
35 | #define INA2XX_POWER 0x03 /* readonly */ | |
36 | #define INA2XX_CURRENT 0x04 /* readonly */ | |
37 | #define INA2XX_CALIBRATION 0x05 | |
38 | ||
39 | /* INA226 register definitions */ | |
40 | #define INA226_MASK_ENABLE 0x06 | |
41 | #define INA226_ALERT_LIMIT 0x07 | |
42 | #define INA226_DIE_ID 0xFF | |
43 | ||
44 | ||
45 | /* register count */ | |
46 | #define INA219_REGISTERS 6 | |
47 | #define INA226_REGISTERS 8 | |
48 | ||
49 | #define INA2XX_MAX_REGISTERS 8 | |
50 | ||
51 | /* settings - depend on use case */ | |
52 | #define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */ | |
53 | #define INA226_CONFIG_DEFAULT 0x4527 /* averages=16 */ | |
54 | ||
55 | /* worst case is 68.10 ms (~14.6Hz, ina219) */ | |
56 | #define INA2XX_CONVERSION_RATE 15 | |
57 | ||
58 | enum ina2xx_ids { ina219, ina226 }; | |
59 | ||
60 | struct ina2xx_data { | |
61 | struct device *hwmon_dev; | |
62 | ||
63 | struct mutex update_lock; | |
64 | bool valid; | |
65 | unsigned long last_updated; | |
66 | ||
67 | int kind; | |
68 | int registers; | |
69 | u16 regs[INA2XX_MAX_REGISTERS]; | |
70 | }; | |
71 | ||
f7c2fe38 FL |
72 | static struct ina2xx_data *ina2xx_update_device(struct device *dev) |
73 | { | |
74 | struct i2c_client *client = to_i2c_client(dev); | |
75 | struct ina2xx_data *data = i2c_get_clientdata(client); | |
76 | struct ina2xx_data *ret = data; | |
77 | ||
78 | mutex_lock(&data->update_lock); | |
79 | ||
80 | if (time_after(jiffies, data->last_updated + | |
81 | HZ / INA2XX_CONVERSION_RATE) || !data->valid) { | |
82 | ||
83 | int i; | |
84 | ||
85 | dev_dbg(&client->dev, "Starting ina2xx update\n"); | |
86 | ||
87 | /* Read all registers */ | |
88 | for (i = 0; i < data->registers; i++) { | |
080b98e9 | 89 | int rv = i2c_smbus_read_word_swapped(client, i); |
f7c2fe38 FL |
90 | if (rv < 0) { |
91 | ret = ERR_PTR(rv); | |
92 | goto abort; | |
93 | } | |
94 | data->regs[i] = rv; | |
95 | } | |
96 | data->last_updated = jiffies; | |
97 | data->valid = 1; | |
98 | } | |
99 | abort: | |
100 | mutex_unlock(&data->update_lock); | |
101 | return ret; | |
102 | } | |
103 | ||
104 | static int ina219_get_value(struct ina2xx_data *data, u8 reg) | |
105 | { | |
106 | /* | |
107 | * calculate exact value for the given register | |
108 | * we assume default power-on reset settings: | |
109 | * bus voltage range 32V | |
110 | * gain = /8 | |
111 | * adc 1 & 2 -> conversion time 532uS | |
112 | * mode is continuous shunt and bus | |
113 | * calibration value is INA219_CALIBRATION_VALUE | |
114 | */ | |
115 | int val = data->regs[reg]; | |
116 | ||
117 | switch (reg) { | |
118 | case INA2XX_SHUNT_VOLTAGE: | |
119 | /* LSB=10uV. Convert to mV. */ | |
120 | val = DIV_ROUND_CLOSEST(val, 100); | |
121 | break; | |
122 | case INA2XX_BUS_VOLTAGE: | |
123 | /* LSB=4mV. Register is not right aligned, convert to mV. */ | |
124 | val = (val >> 3) * 4; | |
125 | break; | |
126 | case INA2XX_POWER: | |
127 | /* LSB=20mW. Convert to uW */ | |
128 | val = val * 20 * 1000; | |
129 | break; | |
130 | case INA2XX_CURRENT: | |
131 | /* LSB=1mA (selected). Is in mA */ | |
132 | break; | |
133 | default: | |
134 | /* programmer goofed */ | |
135 | WARN_ON_ONCE(1); | |
136 | val = 0; | |
137 | break; | |
138 | } | |
139 | ||
140 | return val; | |
141 | } | |
142 | ||
143 | static int ina226_get_value(struct ina2xx_data *data, u8 reg) | |
144 | { | |
145 | /* | |
146 | * calculate exact value for the given register | |
147 | * we assume default power-on reset settings: | |
148 | * bus voltage range 32V | |
149 | * gain = /8 | |
150 | * adc 1 & 2 -> conversion time 532uS | |
151 | * mode is continuous shunt and bus | |
152 | * calibration value is INA226_CALIBRATION_VALUE | |
153 | */ | |
154 | int val = data->regs[reg]; | |
155 | ||
156 | switch (reg) { | |
157 | case INA2XX_SHUNT_VOLTAGE: | |
158 | /* LSB=2.5uV. Convert to mV. */ | |
159 | val = DIV_ROUND_CLOSEST(val, 400); | |
160 | break; | |
161 | case INA2XX_BUS_VOLTAGE: | |
162 | /* LSB=1.25mV. Convert to mV. */ | |
163 | val = val + DIV_ROUND_CLOSEST(val, 4); | |
164 | break; | |
165 | case INA2XX_POWER: | |
166 | /* LSB=25mW. Convert to uW */ | |
167 | val = val * 25 * 1000; | |
168 | break; | |
169 | case INA2XX_CURRENT: | |
170 | /* LSB=1mA (selected). Is in mA */ | |
171 | break; | |
172 | default: | |
173 | /* programmer goofed */ | |
174 | WARN_ON_ONCE(1); | |
175 | val = 0; | |
176 | break; | |
177 | } | |
178 | ||
179 | return val; | |
180 | } | |
181 | ||
182 | static ssize_t ina2xx_show_value(struct device *dev, | |
183 | struct device_attribute *da, char *buf) | |
184 | { | |
185 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
186 | struct ina2xx_data *data = ina2xx_update_device(dev); | |
187 | int value = 0; | |
188 | ||
189 | if (IS_ERR(data)) | |
190 | return PTR_ERR(data); | |
191 | ||
192 | switch (data->kind) { | |
193 | case ina219: | |
194 | value = ina219_get_value(data, attr->index); | |
195 | break; | |
196 | case ina226: | |
197 | value = ina226_get_value(data, attr->index); | |
198 | break; | |
199 | default: | |
200 | WARN_ON_ONCE(1); | |
201 | break; | |
202 | } | |
203 | return snprintf(buf, PAGE_SIZE, "%d\n", value); | |
204 | } | |
205 | ||
206 | /* shunt voltage */ | |
207 | static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, \ | |
208 | ina2xx_show_value, NULL, INA2XX_SHUNT_VOLTAGE); | |
209 | ||
210 | /* bus voltage */ | |
211 | static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, \ | |
212 | ina2xx_show_value, NULL, INA2XX_BUS_VOLTAGE); | |
213 | ||
214 | /* calculated current */ | |
215 | static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, \ | |
216 | ina2xx_show_value, NULL, INA2XX_CURRENT); | |
217 | ||
218 | /* calculated power */ | |
219 | static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, \ | |
220 | ina2xx_show_value, NULL, INA2XX_POWER); | |
221 | ||
222 | /* pointers to created device attributes */ | |
223 | static struct attribute *ina2xx_attributes[] = { | |
224 | &sensor_dev_attr_in0_input.dev_attr.attr, | |
225 | &sensor_dev_attr_in1_input.dev_attr.attr, | |
226 | &sensor_dev_attr_curr1_input.dev_attr.attr, | |
227 | &sensor_dev_attr_power1_input.dev_attr.attr, | |
228 | NULL, | |
229 | }; | |
230 | ||
231 | static const struct attribute_group ina2xx_group = { | |
232 | .attrs = ina2xx_attributes, | |
233 | }; | |
234 | ||
235 | static int ina2xx_probe(struct i2c_client *client, | |
236 | const struct i2c_device_id *id) | |
237 | { | |
238 | struct i2c_adapter *adapter = client->adapter; | |
239 | struct ina2xx_data *data; | |
240 | struct ina2xx_platform_data *pdata; | |
241 | int ret = 0; | |
242 | long shunt = 10000; /* default shunt value 10mOhms */ | |
243 | ||
244 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA)) | |
245 | return -ENODEV; | |
246 | ||
247 | data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL); | |
248 | if (!data) | |
249 | return -ENOMEM; | |
250 | ||
251 | if (client->dev.platform_data) { | |
252 | pdata = | |
253 | (struct ina2xx_platform_data *)client->dev.platform_data; | |
254 | shunt = pdata->shunt_uohms; | |
255 | } | |
256 | ||
257 | if (shunt <= 0) | |
258 | return -ENODEV; | |
259 | ||
260 | /* set the device type */ | |
261 | data->kind = id->driver_data; | |
262 | ||
263 | switch (data->kind) { | |
264 | case ina219: | |
265 | /* device configuration */ | |
080b98e9 GR |
266 | i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, |
267 | INA219_CONFIG_DEFAULT); | |
f7c2fe38 FL |
268 | |
269 | /* set current LSB to 1mA, shunt is in uOhms */ | |
270 | /* (equation 13 in datasheet) */ | |
080b98e9 GR |
271 | i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, |
272 | 40960000 / shunt); | |
f7c2fe38 FL |
273 | dev_info(&client->dev, |
274 | "power monitor INA219 (Rshunt = %li uOhm)\n", shunt); | |
275 | data->registers = INA219_REGISTERS; | |
276 | break; | |
277 | case ina226: | |
278 | /* device configuration */ | |
080b98e9 GR |
279 | i2c_smbus_write_word_swapped(client, INA2XX_CONFIG, |
280 | INA226_CONFIG_DEFAULT); | |
f7c2fe38 FL |
281 | |
282 | /* set current LSB to 1mA, shunt is in uOhms */ | |
283 | /* (equation 1 in datasheet)*/ | |
080b98e9 GR |
284 | i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION, |
285 | 5120000 / shunt); | |
f7c2fe38 FL |
286 | dev_info(&client->dev, |
287 | "power monitor INA226 (Rshunt = %li uOhm)\n", shunt); | |
288 | data->registers = INA226_REGISTERS; | |
289 | break; | |
290 | default: | |
291 | /* unknown device id */ | |
292 | return -ENODEV; | |
293 | } | |
294 | ||
295 | i2c_set_clientdata(client, data); | |
296 | mutex_init(&data->update_lock); | |
297 | ||
298 | ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group); | |
299 | if (ret) | |
300 | return ret; | |
301 | ||
302 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
303 | if (IS_ERR(data->hwmon_dev)) { | |
304 | ret = PTR_ERR(data->hwmon_dev); | |
305 | goto out_err_hwmon; | |
306 | } | |
307 | ||
308 | return 0; | |
309 | ||
310 | out_err_hwmon: | |
311 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); | |
312 | return ret; | |
313 | } | |
314 | ||
315 | static int ina2xx_remove(struct i2c_client *client) | |
316 | { | |
317 | struct ina2xx_data *data = i2c_get_clientdata(client); | |
318 | ||
319 | hwmon_device_unregister(data->hwmon_dev); | |
320 | sysfs_remove_group(&client->dev.kobj, &ina2xx_group); | |
321 | ||
322 | return 0; | |
323 | } | |
324 | ||
325 | static const struct i2c_device_id ina2xx_id[] = { | |
326 | { "ina219", ina219 }, | |
327 | { "ina226", ina226 }, | |
328 | { } | |
329 | }; | |
330 | MODULE_DEVICE_TABLE(i2c, ina2xx_id); | |
331 | ||
332 | static struct i2c_driver ina2xx_driver = { | |
333 | .driver = { | |
334 | .name = "ina2xx", | |
335 | }, | |
336 | .probe = ina2xx_probe, | |
337 | .remove = ina2xx_remove, | |
338 | .id_table = ina2xx_id, | |
339 | }; | |
340 | ||
341 | static int __init ina2xx_init(void) | |
342 | { | |
343 | return i2c_add_driver(&ina2xx_driver); | |
344 | } | |
345 | ||
346 | static void __exit ina2xx_exit(void) | |
347 | { | |
348 | i2c_del_driver(&ina2xx_driver); | |
349 | } | |
350 | ||
351 | MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>"); | |
352 | MODULE_DESCRIPTION("ina2xx driver"); | |
353 | MODULE_LICENSE("GPL"); | |
354 | ||
355 | module_init(ina2xx_init); | |
356 | module_exit(ina2xx_exit); |