UPSTREAM: binder: fix race that allows malicious free of live buffer
[GitHub/LineageOS/android_kernel_samsung_universal7580.git] / drivers / hwmon / ina2xx.c
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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 *
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8 * INA220:
9 * Bi-Directional Current/Power Monitor with I2C Interface
10 * Datasheet: http://www.ti.com/product/ina220
11 *
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12 * INA226:
13 * Bi-Directional Current/Power Monitor with I2C Interface
14 * Datasheet: http://www.ti.com/product/ina226
15 *
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16 * INA230:
17 * Bi-directional Current/Power Monitor with I2C Interface
18 * Datasheet: http://www.ti.com/product/ina230
19 *
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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>
dcd8f392 36#include <linux/jiffies.h>
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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
67enum ina2xx_ids { ina219, ina226 };
68
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69struct 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
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79struct ina2xx_data {
80 struct device *hwmon_dev;
6106db25 81 const struct ina2xx_config *config;
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82
83 struct mutex update_lock;
84 bool valid;
85 unsigned long last_updated;
86
87 int kind;
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88 u16 regs[INA2XX_MAX_REGISTERS];
89};
90
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91static 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
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112static 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 */
6106db25 128 for (i = 0; i < data->config->registers; i++) {
080b98e9 129 int rv = i2c_smbus_read_word_swapped(client, i);
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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 }
139abort:
140 mutex_unlock(&data->update_lock);
141 return ret;
142}
143
6106db25 144static int ina2xx_get_value(struct ina2xx_data *data, u8 reg)
f7c2fe38 145{
6106db25 146 int val;
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147
148 switch (reg) {
149 case INA2XX_SHUNT_VOLTAGE:
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150 /* signed register */
151 val = DIV_ROUND_CLOSEST((s16)data->regs[reg],
6106db25 152 data->config->shunt_div);
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153 break;
154 case INA2XX_BUS_VOLTAGE:
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155 val = (data->regs[reg] >> data->config->bus_voltage_shift)
156 * data->config->bus_voltage_lsb;
157 val = DIV_ROUND_CLOSEST(val, 1000);
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158 break;
159 case INA2XX_POWER:
6106db25 160 val = data->regs[reg] * data->config->power_lsb;
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161 break;
162 case INA2XX_CURRENT:
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163 /* signed register, LSB=1mA (selected), in mA */
164 val = (s16)data->regs[reg];
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165 break;
166 default:
167 /* programmer goofed */
168 WARN_ON_ONCE(1);
169 val = 0;
170 break;
171 }
172
173 return val;
174}
175
176static ssize_t ina2xx_show_value(struct device *dev,
177 struct device_attribute *da, char *buf)
178{
179 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
180 struct ina2xx_data *data = ina2xx_update_device(dev);
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181
182 if (IS_ERR(data))
183 return PTR_ERR(data);
184
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185 return snprintf(buf, PAGE_SIZE, "%d\n",
186 ina2xx_get_value(data, attr->index));
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187}
188
189/* shunt voltage */
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190static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, ina2xx_show_value, NULL,
191 INA2XX_SHUNT_VOLTAGE);
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192
193/* bus voltage */
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194static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ina2xx_show_value, NULL,
195 INA2XX_BUS_VOLTAGE);
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196
197/* calculated current */
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198static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ina2xx_show_value, NULL,
199 INA2XX_CURRENT);
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200
201/* calculated power */
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202static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ina2xx_show_value, NULL,
203 INA2XX_POWER);
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204
205/* pointers to created device attributes */
206static struct attribute *ina2xx_attributes[] = {
207 &sensor_dev_attr_in0_input.dev_attr.attr,
208 &sensor_dev_attr_in1_input.dev_attr.attr,
209 &sensor_dev_attr_curr1_input.dev_attr.attr,
210 &sensor_dev_attr_power1_input.dev_attr.attr,
211 NULL,
212};
213
214static const struct attribute_group ina2xx_group = {
215 .attrs = ina2xx_attributes,
216};
217
218static int ina2xx_probe(struct i2c_client *client,
219 const struct i2c_device_id *id)
220{
221 struct i2c_adapter *adapter = client->adapter;
222 struct ina2xx_data *data;
223 struct ina2xx_platform_data *pdata;
6106db25 224 int ret;
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225 long shunt = 10000; /* default shunt value 10mOhms */
226
227 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
228 return -ENODEV;
229
230 data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
231 if (!data)
232 return -ENOMEM;
233
234 if (client->dev.platform_data) {
235 pdata =
236 (struct ina2xx_platform_data *)client->dev.platform_data;
237 shunt = pdata->shunt_uohms;
238 }
239
240 if (shunt <= 0)
241 return -ENODEV;
242
243 /* set the device type */
244 data->kind = id->driver_data;
6106db25 245 data->config = &ina2xx_config[data->kind];
f7c2fe38 246
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247 /* device configuration */
248 i2c_smbus_write_word_swapped(client, INA2XX_CONFIG,
249 data->config->config_default);
250 /* set current LSB to 1mA, shunt is in uOhms */
251 /* (equation 13 in datasheet) */
252 i2c_smbus_write_word_swapped(client, INA2XX_CALIBRATION,
253 data->config->calibration_factor / shunt);
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254
255 i2c_set_clientdata(client, data);
256 mutex_init(&data->update_lock);
257
258 ret = sysfs_create_group(&client->dev.kobj, &ina2xx_group);
259 if (ret)
260 return ret;
261
262 data->hwmon_dev = hwmon_device_register(&client->dev);
263 if (IS_ERR(data->hwmon_dev)) {
264 ret = PTR_ERR(data->hwmon_dev);
265 goto out_err_hwmon;
266 }
267
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268 dev_info(&client->dev, "power monitor %s (Rshunt = %li uOhm)\n",
269 id->name, shunt);
270
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271 return 0;
272
273out_err_hwmon:
274 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
275 return ret;
276}
277
278static int ina2xx_remove(struct i2c_client *client)
279{
280 struct ina2xx_data *data = i2c_get_clientdata(client);
281
282 hwmon_device_unregister(data->hwmon_dev);
283 sysfs_remove_group(&client->dev.kobj, &ina2xx_group);
284
285 return 0;
286}
287
288static const struct i2c_device_id ina2xx_id[] = {
289 { "ina219", ina219 },
dc92cd0c 290 { "ina220", ina219 },
f7c2fe38 291 { "ina226", ina226 },
dc92cd0c 292 { "ina230", ina226 },
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293 { }
294};
295MODULE_DEVICE_TABLE(i2c, ina2xx_id);
296
297static struct i2c_driver ina2xx_driver = {
298 .driver = {
299 .name = "ina2xx",
300 },
301 .probe = ina2xx_probe,
302 .remove = ina2xx_remove,
303 .id_table = ina2xx_id,
304};
305
d835ca0f 306module_i2c_driver(ina2xx_driver);
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307
308MODULE_AUTHOR("Lothar Felten <l-felten@ti.com>");
309MODULE_DESCRIPTION("ina2xx driver");
310MODULE_LICENSE("GPL");