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Dirk Eibach8c22a8f2011-03-21 17:59:36 +01001/*
2 * ads1015.c - lm_sensors driver for ads1015 12-bit 4-input ADC
3 * (C) Copyright 2010
4 * Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
5 *
6 * Based on the ads7828 driver by Steve Hardy.
7 *
8 * Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads1015.pdf
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */
24
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/slab.h>
28#include <linux/delay.h>
29#include <linux/i2c.h>
30#include <linux/hwmon.h>
31#include <linux/hwmon-sysfs.h>
32#include <linux/err.h>
33#include <linux/mutex.h>
34#include <linux/of.h>
35
36#include <linux/i2c/ads1015.h>
37
38/* ADS1015 registers */
39enum {
40 ADS1015_CONVERSION = 0,
41 ADS1015_CONFIG = 1,
42};
43
44/* PGA fullscale voltages in mV */
45static const unsigned int fullscale_table[8] = {
46 6144, 4096, 2048, 1024, 512, 256, 256, 256 };
47
Dirk Eibachc0046862011-03-21 17:59:37 +010048/* Data rates in samples per second */
49static const unsigned int data_rate_table[8] = {
50 128, 250, 490, 920, 1600, 2400, 3300, 3300 };
51
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010052#define ADS1015_DEFAULT_CHANNELS 0xff
Dirk Eibachc0046862011-03-21 17:59:37 +010053#define ADS1015_DEFAULT_PGA 2
54#define ADS1015_DEFAULT_DATA_RATE 4
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010055
56struct ads1015_data {
57 struct device *hwmon_dev;
58 struct mutex update_lock; /* mutex protect updates */
Dirk Eibachc0046862011-03-21 17:59:37 +010059 struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010060};
61
Guenter Roeck1196573f2012-04-09 13:53:00 -040062static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010063{
64 u16 config;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010065 struct ads1015_data *data = i2c_get_clientdata(client);
Dirk Eibachc0046862011-03-21 17:59:37 +010066 unsigned int pga = data->channel_data[channel].pga;
Dirk Eibachc0046862011-03-21 17:59:37 +010067 unsigned int data_rate = data->channel_data[channel].data_rate;
68 unsigned int conversion_time_ms;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010069 int res;
70
71 mutex_lock(&data->update_lock);
72
Dirk Eibachc0046862011-03-21 17:59:37 +010073 /* get channel parameters */
Jean Delvare90f41022011-11-04 12:00:47 +010074 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010075 if (res < 0)
76 goto err_unlock;
77 config = res;
Dirk Eibachc0046862011-03-21 17:59:37 +010078 conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010079
Dirk Eibachc0046862011-03-21 17:59:37 +010080 /* setup and start single conversion */
81 config &= 0x001f;
82 config |= (1 << 15) | (1 << 8);
83 config |= (channel & 0x0007) << 12;
84 config |= (pga & 0x0007) << 9;
85 config |= (data_rate & 0x0007) << 5;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010086
Jean Delvare90f41022011-11-04 12:00:47 +010087 res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010088 if (res < 0)
89 goto err_unlock;
Dirk Eibachc0046862011-03-21 17:59:37 +010090
91 /* wait until conversion finished */
92 msleep(conversion_time_ms);
Jean Delvare90f41022011-11-04 12:00:47 +010093 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
Dirk Eibachc0046862011-03-21 17:59:37 +010094 if (res < 0)
95 goto err_unlock;
96 config = res;
97 if (!(config & (1 << 15))) {
98 /* conversion not finished in time */
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010099 res = -EIO;
100 goto err_unlock;
101 }
102
Jean Delvare90f41022011-11-04 12:00:47 +0100103 res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100104
105err_unlock:
106 mutex_unlock(&data->update_lock);
107 return res;
108}
109
Guenter Roeck1196573f2012-04-09 13:53:00 -0400110static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
111 s16 reg)
112{
113 struct ads1015_data *data = i2c_get_clientdata(client);
114 unsigned int pga = data->channel_data[channel].pga;
115 int fullscale = fullscale_table[pga];
116
117 return DIV_ROUND_CLOSEST(reg * fullscale, 0x7ff0);
118}
119
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100120/* sysfs callback function */
121static ssize_t show_in(struct device *dev, struct device_attribute *da,
122 char *buf)
123{
124 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
125 struct i2c_client *client = to_i2c_client(dev);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100126 int res;
Guenter Roeck1196573f2012-04-09 13:53:00 -0400127 int index = attr->index;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100128
Guenter Roeck1196573f2012-04-09 13:53:00 -0400129 res = ads1015_read_adc(client, index);
130 if (res < 0)
131 return res;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100132
Guenter Roeck1196573f2012-04-09 13:53:00 -0400133 return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100134}
135
Jean Delvarefdf241a2011-03-21 17:59:37 +0100136static const struct sensor_device_attribute ads1015_in[] = {
137 SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
138 SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
139 SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
140 SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3),
141 SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4),
142 SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5),
143 SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6),
144 SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7),
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100145};
146
147/*
148 * Driver interface
149 */
150
151static int ads1015_remove(struct i2c_client *client)
152{
153 struct ads1015_data *data = i2c_get_clientdata(client);
Jean Delvarefdf241a2011-03-21 17:59:37 +0100154 int k;
155
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100156 hwmon_device_unregister(data->hwmon_dev);
Dirk Eibachc0046862011-03-21 17:59:37 +0100157 for (k = 0; k < ADS1015_CHANNELS; ++k)
Jean Delvarefdf241a2011-03-21 17:59:37 +0100158 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100159 return 0;
160}
161
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100162#ifdef CONFIG_OF
Dirk Eibachc0046862011-03-21 17:59:37 +0100163static int ads1015_get_channels_config_of(struct i2c_client *client)
164{
165 struct ads1015_data *data = i2c_get_clientdata(client);
166 struct device_node *node;
167
168 if (!client->dev.of_node
169 || !of_get_next_child(client->dev.of_node, NULL))
170 return -EINVAL;
171
172 for_each_child_of_node(client->dev.of_node, node) {
173 const __be32 *property;
174 int len;
175 unsigned int channel;
176 unsigned int pga = ADS1015_DEFAULT_PGA;
177 unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
178
179 property = of_get_property(node, "reg", &len);
180 if (!property || len != sizeof(int)) {
181 dev_err(&client->dev, "invalid reg on %s\n",
182 node->full_name);
183 continue;
184 }
185
186 channel = be32_to_cpup(property);
187 if (channel > ADS1015_CHANNELS) {
188 dev_err(&client->dev,
189 "invalid channel index %d on %s\n",
190 channel, node->full_name);
191 continue;
192 }
193
194 property = of_get_property(node, "ti,gain", &len);
195 if (property && len == sizeof(int)) {
196 pga = be32_to_cpup(property);
197 if (pga > 6) {
198 dev_err(&client->dev,
199 "invalid gain on %s\n",
200 node->full_name);
201 }
202 }
203
204 property = of_get_property(node, "ti,datarate", &len);
205 if (property && len == sizeof(int)) {
206 data_rate = be32_to_cpup(property);
207 if (data_rate > 7) {
208 dev_err(&client->dev,
209 "invalid data_rate on %s\n",
210 node->full_name);
211 }
212 }
213
214 data->channel_data[channel].enabled = true;
215 data->channel_data[channel].pga = pga;
216 data->channel_data[channel].data_rate = data_rate;
217 }
218
219 return 0;
220}
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100221#endif
222
Dirk Eibachc0046862011-03-21 17:59:37 +0100223static void ads1015_get_channels_config(struct i2c_client *client)
224{
225 unsigned int k;
226 struct ads1015_data *data = i2c_get_clientdata(client);
227 struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
228
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100229 /* prefer platform data */
Dirk Eibachc0046862011-03-21 17:59:37 +0100230 if (pdata) {
231 memcpy(data->channel_data, pdata->channel_data,
232 sizeof(data->channel_data));
233 return;
234 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100235
236#ifdef CONFIG_OF
Dirk Eibachc0046862011-03-21 17:59:37 +0100237 if (!ads1015_get_channels_config_of(client))
238 return;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100239#endif
240
241 /* fallback on default configuration */
Dirk Eibachc0046862011-03-21 17:59:37 +0100242 for (k = 0; k < ADS1015_CHANNELS; ++k) {
243 data->channel_data[k].enabled = true;
244 data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
245 data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
246 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100247}
248
249static int ads1015_probe(struct i2c_client *client,
250 const struct i2c_device_id *id)
251{
252 struct ads1015_data *data;
253 int err;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100254 unsigned int k;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100255
Guenter Roeck57457e32012-06-02 09:58:00 -0700256 data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
257 GFP_KERNEL);
258 if (!data)
259 return -ENOMEM;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100260
261 i2c_set_clientdata(client, data);
262 mutex_init(&data->update_lock);
263
264 /* build sysfs attribute group */
Dirk Eibachc0046862011-03-21 17:59:37 +0100265 ads1015_get_channels_config(client);
266 for (k = 0; k < ADS1015_CHANNELS; ++k) {
267 if (!data->channel_data[k].enabled)
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100268 continue;
Jean Delvarefdf241a2011-03-21 17:59:37 +0100269 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
270 if (err)
Guenter Roeck363434b2012-02-22 08:13:52 -0800271 goto exit_remove;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100272 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100273
274 data->hwmon_dev = hwmon_device_register(&client->dev);
275 if (IS_ERR(data->hwmon_dev)) {
276 err = PTR_ERR(data->hwmon_dev);
277 goto exit_remove;
278 }
279
280 return 0;
281
282exit_remove:
Dirk Eibachc0046862011-03-21 17:59:37 +0100283 for (k = 0; k < ADS1015_CHANNELS; ++k)
Jean Delvarefdf241a2011-03-21 17:59:37 +0100284 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100285 return err;
286}
287
288static const struct i2c_device_id ads1015_id[] = {
289 { "ads1015", 0 },
290 { }
291};
292MODULE_DEVICE_TABLE(i2c, ads1015_id);
293
294static struct i2c_driver ads1015_driver = {
295 .driver = {
296 .name = "ads1015",
297 },
298 .probe = ads1015_probe,
299 .remove = ads1015_remove,
300 .id_table = ads1015_id,
301};
302
Axel Linf0967ee2012-01-20 15:38:18 +0800303module_i2c_driver(ads1015_driver);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100304
305MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
306MODULE_DESCRIPTION("ADS1015 driver");
307MODULE_LICENSE("GPL");