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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 */
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +040049static const unsigned int data_rate_table_1015[8] = {
50 128, 250, 490, 920, 1600, 2400, 3300, 3300
51};
52
53static const unsigned int data_rate_table_1115[8] = {
54 8, 16, 32, 64, 128, 250, 475, 860
55};
Dirk Eibachc0046862011-03-21 17:59:37 +010056
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010057#define ADS1015_DEFAULT_CHANNELS 0xff
Dirk Eibachc0046862011-03-21 17:59:37 +010058#define ADS1015_DEFAULT_PGA 2
59#define ADS1015_DEFAULT_DATA_RATE 4
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010060
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +040061enum ads1015_chips {
62 ads1015,
63 ads1115,
64};
65
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010066struct ads1015_data {
67 struct device *hwmon_dev;
68 struct mutex update_lock; /* mutex protect updates */
Dirk Eibachc0046862011-03-21 17:59:37 +010069 struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +040070 enum ads1015_chips id;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010071};
72
Guenter Roeck1196573f2012-04-09 13:53:00 -040073static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010074{
75 u16 config;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010076 struct ads1015_data *data = i2c_get_clientdata(client);
Dirk Eibachc0046862011-03-21 17:59:37 +010077 unsigned int pga = data->channel_data[channel].pga;
Dirk Eibachc0046862011-03-21 17:59:37 +010078 unsigned int data_rate = data->channel_data[channel].data_rate;
79 unsigned int conversion_time_ms;
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +040080 const unsigned int * const rate_table = data->id == ads1115 ?
81 data_rate_table_1115 : data_rate_table_1015;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010082 int res;
83
84 mutex_lock(&data->update_lock);
85
Dirk Eibachc0046862011-03-21 17:59:37 +010086 /* get channel parameters */
Jean Delvare90f41022011-11-04 12:00:47 +010087 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010088 if (res < 0)
89 goto err_unlock;
90 config = res;
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +040091 conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010092
Dirk Eibachc0046862011-03-21 17:59:37 +010093 /* setup and start single conversion */
94 config &= 0x001f;
95 config |= (1 << 15) | (1 << 8);
96 config |= (channel & 0x0007) << 12;
97 config |= (pga & 0x0007) << 9;
98 config |= (data_rate & 0x0007) << 5;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +010099
Jean Delvare90f41022011-11-04 12:00:47 +0100100 res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100101 if (res < 0)
102 goto err_unlock;
Dirk Eibachc0046862011-03-21 17:59:37 +0100103
104 /* wait until conversion finished */
105 msleep(conversion_time_ms);
Jean Delvare90f41022011-11-04 12:00:47 +0100106 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
Dirk Eibachc0046862011-03-21 17:59:37 +0100107 if (res < 0)
108 goto err_unlock;
109 config = res;
110 if (!(config & (1 << 15))) {
111 /* conversion not finished in time */
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100112 res = -EIO;
113 goto err_unlock;
114 }
115
Jean Delvare90f41022011-11-04 12:00:47 +0100116 res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100117
118err_unlock:
119 mutex_unlock(&data->update_lock);
120 return res;
121}
122
Guenter Roeck1196573f2012-04-09 13:53:00 -0400123static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
124 s16 reg)
125{
126 struct ads1015_data *data = i2c_get_clientdata(client);
127 unsigned int pga = data->channel_data[channel].pga;
128 int fullscale = fullscale_table[pga];
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +0400129 const unsigned mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
Guenter Roeck1196573f2012-04-09 13:53:00 -0400130
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +0400131 return DIV_ROUND_CLOSEST(reg * fullscale, mask);
Guenter Roeck1196573f2012-04-09 13:53:00 -0400132}
133
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100134/* sysfs callback function */
135static ssize_t show_in(struct device *dev, struct device_attribute *da,
136 char *buf)
137{
138 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
139 struct i2c_client *client = to_i2c_client(dev);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100140 int res;
Guenter Roeck1196573f2012-04-09 13:53:00 -0400141 int index = attr->index;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100142
Guenter Roeck1196573f2012-04-09 13:53:00 -0400143 res = ads1015_read_adc(client, index);
144 if (res < 0)
145 return res;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100146
Guenter Roeck1196573f2012-04-09 13:53:00 -0400147 return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100148}
149
Jean Delvarefdf241a2011-03-21 17:59:37 +0100150static const struct sensor_device_attribute ads1015_in[] = {
151 SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0),
152 SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1),
153 SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2),
154 SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3),
155 SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4),
156 SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5),
157 SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6),
158 SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7),
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100159};
160
161/*
162 * Driver interface
163 */
164
165static int ads1015_remove(struct i2c_client *client)
166{
167 struct ads1015_data *data = i2c_get_clientdata(client);
Jean Delvarefdf241a2011-03-21 17:59:37 +0100168 int k;
169
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100170 hwmon_device_unregister(data->hwmon_dev);
Dirk Eibachc0046862011-03-21 17:59:37 +0100171 for (k = 0; k < ADS1015_CHANNELS; ++k)
Jean Delvarefdf241a2011-03-21 17:59:37 +0100172 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100173 return 0;
174}
175
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100176#ifdef CONFIG_OF
Dirk Eibachc0046862011-03-21 17:59:37 +0100177static int ads1015_get_channels_config_of(struct i2c_client *client)
178{
179 struct ads1015_data *data = i2c_get_clientdata(client);
180 struct device_node *node;
181
182 if (!client->dev.of_node
183 || !of_get_next_child(client->dev.of_node, NULL))
184 return -EINVAL;
185
186 for_each_child_of_node(client->dev.of_node, node) {
Axel Lin8e357622014-08-05 10:56:47 +0800187 u32 pval;
Dirk Eibachc0046862011-03-21 17:59:37 +0100188 unsigned int channel;
189 unsigned int pga = ADS1015_DEFAULT_PGA;
190 unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
191
Axel Lin8e357622014-08-05 10:56:47 +0800192 if (of_property_read_u32(node, "reg", &pval)) {
Dirk Eibachc0046862011-03-21 17:59:37 +0100193 dev_err(&client->dev, "invalid reg on %s\n",
194 node->full_name);
195 continue;
196 }
197
Axel Lin8e357622014-08-05 10:56:47 +0800198 channel = pval;
Axel Lin56de1372014-07-30 11:13:52 +0800199 if (channel >= ADS1015_CHANNELS) {
Dirk Eibachc0046862011-03-21 17:59:37 +0100200 dev_err(&client->dev,
201 "invalid channel index %d on %s\n",
202 channel, node->full_name);
203 continue;
204 }
205
Axel Lin8e357622014-08-05 10:56:47 +0800206 if (!of_property_read_u32(node, "ti,gain", &pval)) {
207 pga = pval;
Dirk Eibachc0046862011-03-21 17:59:37 +0100208 if (pga > 6) {
Axel Lin8e357622014-08-05 10:56:47 +0800209 dev_err(&client->dev, "invalid gain on %s\n",
Dirk Eibachc0046862011-03-21 17:59:37 +0100210 node->full_name);
Axel Line9814292014-08-05 09:59:49 +0800211 return -EINVAL;
Dirk Eibachc0046862011-03-21 17:59:37 +0100212 }
213 }
214
Axel Lin8e357622014-08-05 10:56:47 +0800215 if (!of_property_read_u32(node, "ti,datarate", &pval)) {
216 data_rate = pval;
Dirk Eibachc0046862011-03-21 17:59:37 +0100217 if (data_rate > 7) {
218 dev_err(&client->dev,
219 "invalid data_rate on %s\n",
220 node->full_name);
Axel Line9814292014-08-05 09:59:49 +0800221 return -EINVAL;
Dirk Eibachc0046862011-03-21 17:59:37 +0100222 }
223 }
224
225 data->channel_data[channel].enabled = true;
226 data->channel_data[channel].pga = pga;
227 data->channel_data[channel].data_rate = data_rate;
228 }
229
230 return 0;
231}
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100232#endif
233
Dirk Eibachc0046862011-03-21 17:59:37 +0100234static void ads1015_get_channels_config(struct i2c_client *client)
235{
236 unsigned int k;
237 struct ads1015_data *data = i2c_get_clientdata(client);
238 struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
239
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100240 /* prefer platform data */
Dirk Eibachc0046862011-03-21 17:59:37 +0100241 if (pdata) {
242 memcpy(data->channel_data, pdata->channel_data,
243 sizeof(data->channel_data));
244 return;
245 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100246
247#ifdef CONFIG_OF
Dirk Eibachc0046862011-03-21 17:59:37 +0100248 if (!ads1015_get_channels_config_of(client))
249 return;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100250#endif
251
252 /* fallback on default configuration */
Dirk Eibachc0046862011-03-21 17:59:37 +0100253 for (k = 0; k < ADS1015_CHANNELS; ++k) {
254 data->channel_data[k].enabled = true;
255 data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
256 data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
257 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100258}
259
260static int ads1015_probe(struct i2c_client *client,
261 const struct i2c_device_id *id)
262{
263 struct ads1015_data *data;
264 int err;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100265 unsigned int k;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100266
Guenter Roeck57457e32012-06-02 09:58:00 -0700267 data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
268 GFP_KERNEL);
269 if (!data)
270 return -ENOMEM;
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +0400271 data->id = id->driver_data;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100272 i2c_set_clientdata(client, data);
273 mutex_init(&data->update_lock);
274
275 /* build sysfs attribute group */
Dirk Eibachc0046862011-03-21 17:59:37 +0100276 ads1015_get_channels_config(client);
277 for (k = 0; k < ADS1015_CHANNELS; ++k) {
278 if (!data->channel_data[k].enabled)
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100279 continue;
Jean Delvarefdf241a2011-03-21 17:59:37 +0100280 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
281 if (err)
Guenter Roeck363434b2012-02-22 08:13:52 -0800282 goto exit_remove;
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100283 }
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100284
285 data->hwmon_dev = hwmon_device_register(&client->dev);
286 if (IS_ERR(data->hwmon_dev)) {
287 err = PTR_ERR(data->hwmon_dev);
288 goto exit_remove;
289 }
290
291 return 0;
292
293exit_remove:
Dirk Eibachc0046862011-03-21 17:59:37 +0100294 for (k = 0; k < ADS1015_CHANNELS; ++k)
Jean Delvarefdf241a2011-03-21 17:59:37 +0100295 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100296 return err;
297}
298
299static const struct i2c_device_id ads1015_id[] = {
Evgeniy Dushistov60c1f312013-08-01 23:23:48 +0400300 { "ads1015", ads1015},
301 { "ads1115", ads1115},
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100302 { }
303};
304MODULE_DEVICE_TABLE(i2c, ads1015_id);
305
306static struct i2c_driver ads1015_driver = {
307 .driver = {
308 .name = "ads1015",
309 },
310 .probe = ads1015_probe,
311 .remove = ads1015_remove,
312 .id_table = ads1015_id,
313};
314
Axel Linf0967ee2012-01-20 15:38:18 +0800315module_i2c_driver(ads1015_driver);
Dirk Eibach8c22a8f2011-03-21 17:59:36 +0100316
317MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
318MODULE_DESCRIPTION("ADS1015 driver");
319MODULE_LICENSE("GPL");