Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[firefly-linux-kernel-4.4.55.git] / drivers / hwmon / ina2xx.c
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  * INA220:
9  * Bi-Directional Current/Power Monitor with I2C Interface
10  * Datasheet: http://www.ti.com/product/ina220
11  *
12  * INA226:
13  * Bi-Directional Current/Power Monitor with I2C Interface
14  * Datasheet: http://www.ti.com/product/ina226
15  *
16  * INA230:
17  * Bi-directional Current/Power Monitor with I2C Interface
18  * Datasheet: http://www.ti.com/product/ina230
19  *
20  * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
21  * Thanks to Jan Volkering
22  *
23  * This program is free software; you can redistribute it and/or modify
24  * it under the terms of the GNU General Public License as published by
25  * the Free Software Foundation; version 2 of the License.
26  */
27
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/err.h>
32 #include <linux/slab.h>
33 #include <linux/i2c.h>
34 #include <linux/hwmon.h>
35 #include <linux/hwmon-sysfs.h>
36 #include <linux/jiffies.h>
37
38 #include <linux/platform_data/ina2xx.h>
39
40 /* common register definitions */
41 #define INA2XX_CONFIG                   0x00
42 #define INA2XX_SHUNT_VOLTAGE            0x01 /* readonly */
43 #define INA2XX_BUS_VOLTAGE              0x02 /* readonly */
44 #define INA2XX_POWER                    0x03 /* readonly */
45 #define INA2XX_CURRENT                  0x04 /* readonly */
46 #define INA2XX_CALIBRATION              0x05
47
48 /* INA226 register definitions */
49 #define INA226_MASK_ENABLE              0x06
50 #define INA226_ALERT_LIMIT              0x07
51 #define INA226_DIE_ID                   0xFF
52
53
54 /* register count */
55 #define INA219_REGISTERS                6
56 #define INA226_REGISTERS                8
57
58 #define INA2XX_MAX_REGISTERS            8
59
60 /* settings - depend on use case */
61 #define INA219_CONFIG_DEFAULT           0x399F  /* PGA=8 */
62 #define INA226_CONFIG_DEFAULT           0x4527  /* averages=16 */
63
64 /* worst case is 68.10 ms (~14.6Hz, ina219) */
65 #define INA2XX_CONVERSION_RATE          15
66
67 enum ina2xx_ids { ina219, ina226 };
68
69 struct ina2xx_config {
70         u16 config_default;
71         int calibration_factor;
72         int registers;
73         int shunt_div;
74         int bus_voltage_shift;
75         int bus_voltage_lsb;    /* uV */
76         int power_lsb;          /* uW */
77 };
78
79 struct ina2xx_data {
80         struct device *hwmon_dev;
81         const struct ina2xx_config *config;
82
83         struct mutex update_lock;
84         bool valid;
85         unsigned long last_updated;
86
87         int kind;
88         u16 regs[INA2XX_MAX_REGISTERS];
89 };
90
91 static const struct ina2xx_config ina2xx_config[] = {
92         [ina219] = {
93                 .config_default = INA219_CONFIG_DEFAULT,
94                 .calibration_factor = 40960000,
95                 .registers = INA219_REGISTERS,
96                 .shunt_div = 100,
97                 .bus_voltage_shift = 3,
98                 .bus_voltage_lsb = 4000,
99                 .power_lsb = 20000,
100         },
101         [ina226] = {
102                 .config_default = INA226_CONFIG_DEFAULT,
103                 .calibration_factor = 5120000,
104                 .registers = INA226_REGISTERS,
105                 .shunt_div = 400,
106                 .bus_voltage_shift = 0,
107                 .bus_voltage_lsb = 1250,
108                 .power_lsb = 25000,
109         },
110 };
111
112 static struct ina2xx_data *ina2xx_update_device(struct device *dev)
113 {
114         struct i2c_client *client = to_i2c_client(dev);
115         struct ina2xx_data *data = i2c_get_clientdata(client);
116         struct ina2xx_data *ret = data;
117
118         mutex_lock(&data->update_lock);
119
120         if (time_after(jiffies, data->last_updated +
121                        HZ / INA2XX_CONVERSION_RATE) || !data->valid) {
122
123                 int i;
124
125                 dev_dbg(&client->dev, "Starting ina2xx update\n");
126
127                 /* Read all registers */
128                 for (i = 0; i < data->config->registers; i++) {
129                         int rv = i2c_smbus_read_word_swapped(client, i);
130                         if (rv < 0) {
131                                 ret = ERR_PTR(rv);
132                                 goto abort;
133                         }
134                         data->regs[i] = rv;
135                 }
136                 data->last_updated = jiffies;
137                 data->valid = 1;
138         }
139 abort:
140         mutex_unlock(&data->update_lock);
141         return ret;
142 }
143
144 static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
145 {
146         int val;
147
148         switch (reg) {
149         case INA2XX_SHUNT_VOLTAGE:
150                 val = DIV_ROUND_CLOSEST(data->regs[reg],
151                                         data->config->shunt_div);
152                 break;
153         case INA2XX_BUS_VOLTAGE:
154                 val = (data->regs[reg] >> data->config->bus_voltage_shift)
155                   * data->config->bus_voltage_lsb;
156                 val = DIV_ROUND_CLOSEST(val, 1000);
157                 break;
158         case INA2XX_POWER:
159                 val = data->regs[reg] * data->config->power_lsb;
160                 break;
161         case INA2XX_CURRENT:
162                 /* LSB=1mA (selected). Is in mA */
163                 val = data->regs[reg];
164                 break;
165         default:
166                 /* programmer goofed */
167                 WARN_ON_ONCE(1);
168                 val = 0;
169                 break;
170         }
171
172         return val;
173 }
174
175 static ssize_t ina2xx_show_value(struct device *dev,
176                                  struct device_attribute *da, char *buf)
177 {
178         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
179         struct ina2xx_data *data = ina2xx_update_device(dev);
180
181         if (IS_ERR(data))
182                 return PTR_ERR(data);
183
184         return snprintf(buf, PAGE_SIZE, "%d\n",
185                         ina2xx_get_value(data, attr->index));
186 }
187
188 /* shunt voltage */
189 static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
190                           INA2XX_SHUNT_VOLTAGE);
191
192 /* bus voltage */
193 static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
194                           INA2XX_BUS_VOLTAGE);
195
196 /* calculated current */
197 static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
198                           INA2XX_CURRENT);
199
200 /* calculated power */
201 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
202                           INA2XX_POWER);
203
204 /* pointers to created device attributes */
205 static struct attribute *ina2xx_attributes[] = {
206         &sensor_dev_attr_in0_input.dev_attr.attr,
207         &sensor_dev_attr_in1_input.dev_attr.attr,
208         &sensor_dev_attr_curr1_input.dev_attr.attr,
209         &sensor_dev_attr_power1_input.dev_attr.attr,
210         NULL,
211 };
212
213 static const struct attribute_group ina2xx_group = {
214         .attrs = ina2xx_attributes,
215 };
216
217 static int ina2xx_probe(struct i2c_client *client,
218                         const struct i2c_device_id *id)
219 {
220         struct i2c_adapter *adapter = client->adapter;
221         struct ina2xx_data *data;
222         struct ina2xx_platform_data *pdata;
223         int ret;
224         long shunt = 10000; /* default shunt value 10mOhms */
225
226         if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
227                 return -ENODEV;
228
229         data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
230         if (!data)
231                 return -ENOMEM;
232
233         if (client->dev.platform_data) {
234                 pdata =
235                   (struct ina2xx_platform_data *)client->dev.platform_data;
236                 shunt = pdata->shunt_uohms;
237         }
238
239         if (shunt <= 0)
240                 return -ENODEV;
241
242         /* set the device type */
243         data->kind = id->driver_data;
244         data->config = &ina2xx_config[data->kind];
245
246         /* device configuration */
247         i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
248                                      data->config->config_default);
249         /* set current LSB to 1mA, shunt is in uOhms */
250         /* (equation 13 in datasheet) */
251         i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
252                                      data->config->calibration_factor / shunt);
253
254         i2c_set_clientdata(client, data);
255         mutex_init(&data->update_lock);
256
257         ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
258         if (ret)
259                 return ret;
260
261         data->hwmon_dev = hwmon_device_register(&client->dev);
262         if (IS_ERR(data->hwmon_dev)) {
263                 ret = PTR_ERR(data->hwmon_dev);
264                 goto out_err_hwmon;
265         }
266
267         dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n",
268                  id->name, shunt);
269
270         return 0;
271
272 out_err_hwmon:
273         sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
274         return ret;
275 }
276
277 static int ina2xx_remove(struct i2c_client *client)
278 {
279         struct ina2xx_data *data = i2c_get_clientdata(client);
280
281         hwmon_device_unregister(data->hwmon_dev);
282         sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
283
284         return 0;
285 }
286
287 static const struct i2c_device_id ina2xx_id[] = {
288         { "ina219", ina219 },
289         { "ina220", ina219 },
290         { "ina226", ina226 },
291         { "ina230", ina226 },
292         { }
293 };
294 MODULE_DEVICE_TABLE(i2c, ina2xx_id);
295
296 static struct i2c_driver ina2xx_driver = {
297         .driver = {
298                 .name   = "ina2xx",
299         },
300         .probe          = ina2xx_probe,
301         .remove         = ina2xx_remove,
302         .id_table       = ina2xx_id,
303 };
304
305 module_i2c_driver(ina2xx_driver);
306
307 MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
308 MODULE_DESCRIPTION("ina2xx driver");
309 MODULE_LICENSE("GPL");