aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/ina2xx.c
blob: 4958b2f89dcefff53354e18c6c37f6f356f6eeb2 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
/*
 * Driver for Texas Instruments INA219, INA226 power monitor chips
 *
 * INA219:
 * Zero Drift Bi-Directional Current/Power Monitor with I2C Interface
 * Datasheet: http://www.ti.com/product/ina219
 *
 * INA220:
 * Bi-Directional Current/Power Monitor with I2C Interface
 * Datasheet: http://www.ti.com/product/ina220
 *
 * INA226:
 * Bi-Directional Current/Power Monitor with I2C Interface
 * Datasheet: http://www.ti.com/product/ina226
 *
 * INA230:
 * Bi-directional Current/Power Monitor with I2C Interface
 * Datasheet: http://www.ti.com/product/ina230
 *
 * Copyright (C) 2012 Lothar Felten <l-felten@ti.com>
 * Thanks to Jan Volkering
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/jiffies.h>

#include <linux/platform_data/ina2xx.h>

/* common register definitions */
#define INA2XX_CONFIG			0x00
#define INA2XX_SHUNT_VOLTAGE		0x01 /* readonly */
#define INA2XX_BUS_VOLTAGE		0x02 /* readonly */
#define INA2XX_POWER			0x03 /* readonly */
#define INA2XX_CURRENT			0x04 /* readonly */
#define INA2XX_CALIBRATION		0x05

/* INA226 register definitions */
#define INA226_MASK_ENABLE		0x06
#define INA226_ALERT_LIMIT		0x07
#define INA226_DIE_ID			0xFF


/* register count */
#define INA219_REGISTERS		6
#define INA226_REGISTERS		8

#define INA2XX_MAX_REGISTERS		8

/* settings - depend on use case */
#define INA219_CONFIG_DEFAULT		0x399F	/* PGA=8 */
#define INA226_CONFIG_DEFAULT		0x4527	/* averages=16 */

/* worst case is 68.10 ms (~14.6Hz, ina219) */
#define INA2XX_CONVERSION_RATE		15

enum ina2xx_ids { ina219, ina226 };

struct ina2xx_config {
	u16 config_default;
	int calibration_factor;
	int registers;
	int shunt_div;
	int bus_voltage_shift;
	int bus_voltage_lsb;	/* uV */
	int power_lsb;		/* uW */
};

struct ina2xx_data {
	struct device *hwmon_dev;
	const struct ina2xx_config *config;

	struct mutex update_lock;
	bool valid;
	unsigned long last_updated;

	int kind;
	u16 regs[INA2XX_MAX_REGISTERS];
};

static const struct ina2xx_config ina2xx_config[] = {
	[ina219] = {
		.config_default = INA219_CONFIG_DEFAULT,
		.calibration_factor = 40960000,
		.registers = INA219_REGISTERS,
		.shunt_div = 100,
		.bus_voltage_shift = 3,
		.bus_voltage_lsb = 4000,
		.power_lsb = 20000,
	},
	[ina226] = {
		.config_default = INA226_CONFIG_DEFAULT,
		.calibration_factor = 5120000,
		.registers = INA226_REGISTERS,
		.shunt_div = 400,
		.bus_voltage_shift = 0,
		.bus_voltage_lsb = 1250,
		.power_lsb = 25000,
	},
};

static struct ina2xx_data *ina2xx_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ina2xx_data *data = i2c_get_clientdata(client);
	struct ina2xx_data *ret = data;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated +
		       HZ / INA2XX_CONVERSION_RATE) || !data->valid) {

		int i;

		dev_dbg(&client->dev, "Starting ina2xx update\n");

		/* Read all registers */
		for (i = 0; i < data->config->registers; i++) {
			int rv = i2c_smbus_read_word_swapped(client, i);
			if (rv < 0) {
				ret = ERR_PTR(rv);
				goto abort;
			}
			data->regs[i] = rv;
		}
		data->last_updated = jiffies;
		data->valid = 1;
	}
abort:
	mutex_unlock(&data->update_lock);
	return ret;
}

static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
{
	int val;

	switch (reg) {
	case INA2XX_SHUNT_VOLTAGE:
		val = DIV_ROUND_CLOSEST(data->regs[reg],
					data->config->shunt_div);
		break;
	case INA2XX_BUS_VOLTAGE:
		val = (data->regs[reg] >> data->config->bus_voltage_shift)
		  * data->config->bus_voltage_lsb;
		val = DIV_ROUND_CLOSEST(val, 1000);
		break;
	case INA2XX_POWER:
		val = data->regs[reg] * data->config->power_lsb;
		break;
	case INA2XX_CURRENT:
		/* LSB=1mA (selected). Is in mA */
		val = data->regs[reg];
		break;
	default:
		/* programmer goofed */
		WARN_ON_ONCE(1);
		val = 0;
		break;
	}

	return val;
}

static ssize_t ina2xx_show_value(struct device *dev,
				 struct device_attribute *da, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	struct ina2xx_data *data = ina2xx_update_device(dev);

	if (IS_ERR(data))
		return PTR_ERR(data);

	return snprintf(buf, PAGE_SIZE, "%d\n",
			ina2xx_get_value(data, attr->index));
}

/* shunt voltage */
static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
			  INA2XX_SHUNT_VOLTAGE);

/* bus voltage */
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
			  INA2XX_BUS_VOLTAGE);

/* calculated current */
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
			  INA2XX_CURRENT);

/* calculated power */
static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
			  INA2XX_POWER);

/* pointers to created device attributes */
static struct attribute *ina2xx_attributes[] = {
	&sensor_dev_attr_in0_input.dev_attr.attr,
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_curr1_input.dev_attr.attr,
	&sensor_dev_attr_power1_input.dev_attr.attr,
	NULL,
};

static const struct attribute_group ina2xx_group = {
	.attrs = ina2xx_attributes,
};

static int ina2xx_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = client->adapter;
	struct ina2xx_data *data;
	struct ina2xx_platform_data *pdata;
	int ret;
	long shunt = 10000; /* default shunt value 10mOhms */

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	if (client->dev.platform_data) {
		pdata =
		  (struct ina2xx_platform_data *)client->dev.platform_data;
		shunt = pdata->shunt_uohms;
	}

	if (shunt <= 0)
		return -ENODEV;

	/* set the device type */
	data->kind = id->driver_data;
	data->config = &ina2xx_config[data->kind];

	/* device configuration */
	i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
				     data->config->config_default);
	/* set current LSB to 1mA, shunt is in uOhms */
	/* (equation 13 in datasheet) */
	i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
				     data->config->calibration_factor / shunt);

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
	if (ret)
		return ret;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		ret = PTR_ERR(data->hwmon_dev);
		goto out_err_hwmon;
	}

	dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n",
		 id->name, shunt);

	return 0;

out_err_hwmon:
	sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
	return ret;
}

static int ina2xx_remove(struct i2c_client *client)
{
	struct ina2xx_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ina2xx_group);

	return 0;
}

static const struct i2c_device_id ina2xx_id[] = {
	{ "ina219", ina219 },
	{ "ina220", ina219 },
	{ "ina226", ina226 },
	{ "ina230", ina226 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ina2xx_id);

static struct i2c_driver ina2xx_driver = {
	.driver = {
		.name	= "ina2xx",
	},
	.probe		= ina2xx_probe,
	.remove		= ina2xx_remove,
	.id_table	= ina2xx_id,
};

module_i2c_driver(ina2xx_driver);

MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
MODULE_DESCRIPTION("ina2xx driver");
MODULE_LICENSE("GPL");