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8c22a8f5 DE |
1 | /* |
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> | |
a140986f | 34 | #include <linux/of_device.h> |
8c22a8f5 DE |
35 | #include <linux/of.h> |
36 | ||
9010624c | 37 | #include <linux/platform_data/ads1015.h> |
8c22a8f5 DE |
38 | |
39 | /* ADS1015 registers */ | |
40 | enum { | |
41 | ADS1015_CONVERSION = 0, | |
42 | ADS1015_CONFIG = 1, | |
43 | }; | |
44 | ||
45 | /* PGA fullscale voltages in mV */ | |
46 | static const unsigned int fullscale_table[8] = { | |
47 | 6144, 4096, 2048, 1024, 512, 256, 256, 256 }; | |
48 | ||
c0046867 | 49 | /* Data rates in samples per second */ |
60c1f31f ED |
50 | static const unsigned int data_rate_table_1015[8] = { |
51 | 128, 250, 490, 920, 1600, 2400, 3300, 3300 | |
52 | }; | |
53 | ||
54 | static const unsigned int data_rate_table_1115[8] = { | |
55 | 8, 16, 32, 64, 128, 250, 475, 860 | |
56 | }; | |
c0046867 | 57 | |
8c22a8f5 | 58 | #define ADS1015_DEFAULT_CHANNELS 0xff |
c0046867 DE |
59 | #define ADS1015_DEFAULT_PGA 2 |
60 | #define ADS1015_DEFAULT_DATA_RATE 4 | |
8c22a8f5 | 61 | |
60c1f31f ED |
62 | enum ads1015_chips { |
63 | ads1015, | |
64 | ads1115, | |
65 | }; | |
66 | ||
8c22a8f5 DE |
67 | struct ads1015_data { |
68 | struct device *hwmon_dev; | |
69 | struct mutex update_lock; /* mutex protect updates */ | |
c0046867 | 70 | struct ads1015_channel_data channel_data[ADS1015_CHANNELS]; |
60c1f31f | 71 | enum ads1015_chips id; |
8c22a8f5 DE |
72 | }; |
73 | ||
1196573f | 74 | static int ads1015_read_adc(struct i2c_client *client, unsigned int channel) |
8c22a8f5 DE |
75 | { |
76 | u16 config; | |
8c22a8f5 | 77 | struct ads1015_data *data = i2c_get_clientdata(client); |
c0046867 | 78 | unsigned int pga = data->channel_data[channel].pga; |
c0046867 DE |
79 | unsigned int data_rate = data->channel_data[channel].data_rate; |
80 | unsigned int conversion_time_ms; | |
60c1f31f ED |
81 | const unsigned int * const rate_table = data->id == ads1115 ? |
82 | data_rate_table_1115 : data_rate_table_1015; | |
8c22a8f5 DE |
83 | int res; |
84 | ||
85 | mutex_lock(&data->update_lock); | |
86 | ||
c0046867 | 87 | /* get channel parameters */ |
90f4102c | 88 | res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG); |
8c22a8f5 DE |
89 | if (res < 0) |
90 | goto err_unlock; | |
91 | config = res; | |
60c1f31f | 92 | conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]); |
8c22a8f5 | 93 | |
c0046867 DE |
94 | /* setup and start single conversion */ |
95 | config &= 0x001f; | |
96 | config |= (1 << 15) | (1 << 8); | |
97 | config |= (channel & 0x0007) << 12; | |
98 | config |= (pga & 0x0007) << 9; | |
99 | config |= (data_rate & 0x0007) << 5; | |
8c22a8f5 | 100 | |
90f4102c | 101 | res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config); |
8c22a8f5 DE |
102 | if (res < 0) |
103 | goto err_unlock; | |
c0046867 DE |
104 | |
105 | /* wait until conversion finished */ | |
106 | msleep(conversion_time_ms); | |
90f4102c | 107 | res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG); |
c0046867 DE |
108 | if (res < 0) |
109 | goto err_unlock; | |
110 | config = res; | |
111 | if (!(config & (1 << 15))) { | |
112 | /* conversion not finished in time */ | |
8c22a8f5 DE |
113 | res = -EIO; |
114 | goto err_unlock; | |
115 | } | |
116 | ||
90f4102c | 117 | res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION); |
8c22a8f5 DE |
118 | |
119 | err_unlock: | |
120 | mutex_unlock(&data->update_lock); | |
121 | return res; | |
122 | } | |
123 | ||
1196573f GR |
124 | static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel, |
125 | s16 reg) | |
126 | { | |
127 | struct ads1015_data *data = i2c_get_clientdata(client); | |
128 | unsigned int pga = data->channel_data[channel].pga; | |
129 | int fullscale = fullscale_table[pga]; | |
acc14694 | 130 | const int mask = data->id == ads1115 ? 0x7fff : 0x7ff0; |
1196573f | 131 | |
60c1f31f | 132 | return DIV_ROUND_CLOSEST(reg * fullscale, mask); |
1196573f GR |
133 | } |
134 | ||
8c22a8f5 DE |
135 | /* sysfs callback function */ |
136 | static ssize_t show_in(struct device *dev, struct device_attribute *da, | |
137 | char *buf) | |
138 | { | |
139 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
140 | struct i2c_client *client = to_i2c_client(dev); | |
8c22a8f5 | 141 | int res; |
1196573f | 142 | int index = attr->index; |
8c22a8f5 | 143 | |
1196573f GR |
144 | res = ads1015_read_adc(client, index); |
145 | if (res < 0) | |
146 | return res; | |
8c22a8f5 | 147 | |
1196573f | 148 | return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res)); |
8c22a8f5 DE |
149 | } |
150 | ||
fdf241a8 JD |
151 | static const struct sensor_device_attribute ads1015_in[] = { |
152 | SENSOR_ATTR(in0_input, S_IRUGO, show_in, NULL, 0), | |
153 | SENSOR_ATTR(in1_input, S_IRUGO, show_in, NULL, 1), | |
154 | SENSOR_ATTR(in2_input, S_IRUGO, show_in, NULL, 2), | |
155 | SENSOR_ATTR(in3_input, S_IRUGO, show_in, NULL, 3), | |
156 | SENSOR_ATTR(in4_input, S_IRUGO, show_in, NULL, 4), | |
157 | SENSOR_ATTR(in5_input, S_IRUGO, show_in, NULL, 5), | |
158 | SENSOR_ATTR(in6_input, S_IRUGO, show_in, NULL, 6), | |
159 | SENSOR_ATTR(in7_input, S_IRUGO, show_in, NULL, 7), | |
8c22a8f5 DE |
160 | }; |
161 | ||
162 | /* | |
163 | * Driver interface | |
164 | */ | |
165 | ||
166 | static int ads1015_remove(struct i2c_client *client) | |
167 | { | |
168 | struct ads1015_data *data = i2c_get_clientdata(client); | |
fdf241a8 JD |
169 | int k; |
170 | ||
8c22a8f5 | 171 | hwmon_device_unregister(data->hwmon_dev); |
c0046867 | 172 | for (k = 0; k < ADS1015_CHANNELS; ++k) |
fdf241a8 | 173 | device_remove_file(&client->dev, &ads1015_in[k].dev_attr); |
8c22a8f5 DE |
174 | return 0; |
175 | } | |
176 | ||
8c22a8f5 | 177 | #ifdef CONFIG_OF |
c0046867 DE |
178 | static int ads1015_get_channels_config_of(struct i2c_client *client) |
179 | { | |
180 | struct ads1015_data *data = i2c_get_clientdata(client); | |
181 | struct device_node *node; | |
182 | ||
183 | if (!client->dev.of_node | |
184 | || !of_get_next_child(client->dev.of_node, NULL)) | |
185 | return -EINVAL; | |
186 | ||
187 | for_each_child_of_node(client->dev.of_node, node) { | |
8e35762f | 188 | u32 pval; |
c0046867 DE |
189 | unsigned int channel; |
190 | unsigned int pga = ADS1015_DEFAULT_PGA; | |
191 | unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE; | |
192 | ||
8e35762f | 193 | if (of_property_read_u32(node, "reg", &pval)) { |
c0046867 DE |
194 | dev_err(&client->dev, "invalid reg on %s\n", |
195 | node->full_name); | |
196 | continue; | |
197 | } | |
198 | ||
8e35762f | 199 | channel = pval; |
56de1377 | 200 | if (channel >= ADS1015_CHANNELS) { |
c0046867 DE |
201 | dev_err(&client->dev, |
202 | "invalid channel index %d on %s\n", | |
203 | channel, node->full_name); | |
204 | continue; | |
205 | } | |
206 | ||
8e35762f AL |
207 | if (!of_property_read_u32(node, "ti,gain", &pval)) { |
208 | pga = pval; | |
c0046867 | 209 | if (pga > 6) { |
8e35762f | 210 | dev_err(&client->dev, "invalid gain on %s\n", |
c0046867 | 211 | node->full_name); |
e9814295 | 212 | return -EINVAL; |
c0046867 DE |
213 | } |
214 | } | |
215 | ||
8e35762f AL |
216 | if (!of_property_read_u32(node, "ti,datarate", &pval)) { |
217 | data_rate = pval; | |
c0046867 DE |
218 | if (data_rate > 7) { |
219 | dev_err(&client->dev, | |
220 | "invalid data_rate on %s\n", | |
221 | node->full_name); | |
e9814295 | 222 | return -EINVAL; |
c0046867 DE |
223 | } |
224 | } | |
225 | ||
226 | data->channel_data[channel].enabled = true; | |
227 | data->channel_data[channel].pga = pga; | |
228 | data->channel_data[channel].data_rate = data_rate; | |
229 | } | |
230 | ||
231 | return 0; | |
232 | } | |
8c22a8f5 DE |
233 | #endif |
234 | ||
c0046867 DE |
235 | static void ads1015_get_channels_config(struct i2c_client *client) |
236 | { | |
237 | unsigned int k; | |
238 | struct ads1015_data *data = i2c_get_clientdata(client); | |
239 | struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev); | |
240 | ||
8c22a8f5 | 241 | /* prefer platform data */ |
c0046867 DE |
242 | if (pdata) { |
243 | memcpy(data->channel_data, pdata->channel_data, | |
244 | sizeof(data->channel_data)); | |
245 | return; | |
246 | } | |
8c22a8f5 DE |
247 | |
248 | #ifdef CONFIG_OF | |
c0046867 DE |
249 | if (!ads1015_get_channels_config_of(client)) |
250 | return; | |
8c22a8f5 DE |
251 | #endif |
252 | ||
253 | /* fallback on default configuration */ | |
c0046867 DE |
254 | for (k = 0; k < ADS1015_CHANNELS; ++k) { |
255 | data->channel_data[k].enabled = true; | |
256 | data->channel_data[k].pga = ADS1015_DEFAULT_PGA; | |
257 | data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE; | |
258 | } | |
8c22a8f5 DE |
259 | } |
260 | ||
261 | static int ads1015_probe(struct i2c_client *client, | |
262 | const struct i2c_device_id *id) | |
263 | { | |
264 | struct ads1015_data *data; | |
265 | int err; | |
8c22a8f5 | 266 | unsigned int k; |
8c22a8f5 | 267 | |
57457e31 GR |
268 | data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data), |
269 | GFP_KERNEL); | |
270 | if (!data) | |
271 | return -ENOMEM; | |
a140986f JMC |
272 | |
273 | if (client->dev.of_node) | |
274 | data->id = (enum ads1015_chips) | |
275 | of_device_get_match_data(&client->dev); | |
276 | else | |
277 | data->id = id->driver_data; | |
8c22a8f5 DE |
278 | i2c_set_clientdata(client, data); |
279 | mutex_init(&data->update_lock); | |
280 | ||
281 | /* build sysfs attribute group */ | |
c0046867 DE |
282 | ads1015_get_channels_config(client); |
283 | for (k = 0; k < ADS1015_CHANNELS; ++k) { | |
284 | if (!data->channel_data[k].enabled) | |
8c22a8f5 | 285 | continue; |
fdf241a8 JD |
286 | err = device_create_file(&client->dev, &ads1015_in[k].dev_attr); |
287 | if (err) | |
363434b5 | 288 | goto exit_remove; |
8c22a8f5 | 289 | } |
8c22a8f5 DE |
290 | |
291 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
292 | if (IS_ERR(data->hwmon_dev)) { | |
293 | err = PTR_ERR(data->hwmon_dev); | |
294 | goto exit_remove; | |
295 | } | |
296 | ||
297 | return 0; | |
298 | ||
299 | exit_remove: | |
c0046867 | 300 | for (k = 0; k < ADS1015_CHANNELS; ++k) |
fdf241a8 | 301 | device_remove_file(&client->dev, &ads1015_in[k].dev_attr); |
8c22a8f5 DE |
302 | return err; |
303 | } | |
304 | ||
305 | static const struct i2c_device_id ads1015_id[] = { | |
60c1f31f ED |
306 | { "ads1015", ads1015}, |
307 | { "ads1115", ads1115}, | |
8c22a8f5 DE |
308 | { } |
309 | }; | |
310 | MODULE_DEVICE_TABLE(i2c, ads1015_id); | |
311 | ||
a140986f JMC |
312 | static const struct of_device_id ads1015_of_match[] = { |
313 | { | |
314 | .compatible = "ti,ads1015", | |
315 | .data = (void *)ads1015 | |
316 | }, | |
317 | { | |
318 | .compatible = "ti,ads1115", | |
319 | .data = (void *)ads1115 | |
320 | }, | |
321 | { }, | |
322 | }; | |
323 | MODULE_DEVICE_TABLE(of, ads1015_of_match); | |
324 | ||
8c22a8f5 DE |
325 | static struct i2c_driver ads1015_driver = { |
326 | .driver = { | |
327 | .name = "ads1015", | |
a140986f | 328 | .of_match_table = of_match_ptr(ads1015_of_match), |
8c22a8f5 DE |
329 | }, |
330 | .probe = ads1015_probe, | |
331 | .remove = ads1015_remove, | |
332 | .id_table = ads1015_id, | |
333 | }; | |
334 | ||
f0967eea | 335 | module_i2c_driver(ads1015_driver); |
8c22a8f5 DE |
336 | |
337 | MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>"); | |
338 | MODULE_DESCRIPTION("ADS1015 driver"); | |
339 | MODULE_LICENSE("GPL"); |