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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> | |
34 | #include <linux/of.h> | |
35 | ||
36 | #include <linux/i2c/ads1015.h> | |
37 | ||
38 | /* ADS1015 registers */ | |
39 | enum { | |
40 | ADS1015_CONVERSION = 0, | |
41 | ADS1015_CONFIG = 1, | |
42 | }; | |
43 | ||
44 | /* PGA fullscale voltages in mV */ | |
45 | static const unsigned int fullscale_table[8] = { | |
46 | 6144, 4096, 2048, 1024, 512, 256, 256, 256 }; | |
47 | ||
c0046867 DE |
48 | /* Data rates in samples per second */ |
49 | static const unsigned int data_rate_table[8] = { | |
50 | 128, 250, 490, 920, 1600, 2400, 3300, 3300 }; | |
51 | ||
8c22a8f5 | 52 | #define ADS1015_DEFAULT_CHANNELS 0xff |
c0046867 DE |
53 | #define ADS1015_DEFAULT_PGA 2 |
54 | #define ADS1015_DEFAULT_DATA_RATE 4 | |
8c22a8f5 DE |
55 | |
56 | struct ads1015_data { | |
57 | struct device *hwmon_dev; | |
58 | struct mutex update_lock; /* mutex protect updates */ | |
c0046867 | 59 | struct ads1015_channel_data channel_data[ADS1015_CHANNELS]; |
8c22a8f5 DE |
60 | }; |
61 | ||
62 | static s32 ads1015_read_reg(struct i2c_client *client, unsigned int reg) | |
63 | { | |
64 | s32 data = i2c_smbus_read_word_data(client, reg); | |
65 | ||
66 | return (data < 0) ? data : swab16(data); | |
67 | } | |
68 | ||
69 | static s32 ads1015_write_reg(struct i2c_client *client, unsigned int reg, | |
70 | u16 val) | |
71 | { | |
72 | return i2c_smbus_write_word_data(client, reg, swab16(val)); | |
73 | } | |
74 | ||
75 | static int ads1015_read_value(struct i2c_client *client, unsigned int channel, | |
76 | int *value) | |
77 | { | |
78 | u16 config; | |
79 | s16 conversion; | |
8c22a8f5 | 80 | struct ads1015_data *data = i2c_get_clientdata(client); |
c0046867 DE |
81 | unsigned int pga = data->channel_data[channel].pga; |
82 | int fullscale; | |
83 | unsigned int data_rate = data->channel_data[channel].data_rate; | |
84 | unsigned int conversion_time_ms; | |
8c22a8f5 DE |
85 | int res; |
86 | ||
87 | mutex_lock(&data->update_lock); | |
88 | ||
c0046867 | 89 | /* get channel parameters */ |
8c22a8f5 DE |
90 | res = ads1015_read_reg(client, ADS1015_CONFIG); |
91 | if (res < 0) | |
92 | goto err_unlock; | |
93 | config = res; | |
8c22a8f5 | 94 | fullscale = fullscale_table[pga]; |
c0046867 | 95 | conversion_time_ms = DIV_ROUND_UP(1000, data_rate_table[data_rate]); |
8c22a8f5 | 96 | |
c0046867 DE |
97 | /* setup and start single conversion */ |
98 | config &= 0x001f; | |
99 | config |= (1 << 15) | (1 << 8); | |
100 | config |= (channel & 0x0007) << 12; | |
101 | config |= (pga & 0x0007) << 9; | |
102 | config |= (data_rate & 0x0007) << 5; | |
8c22a8f5 | 103 | |
8c22a8f5 DE |
104 | res = ads1015_write_reg(client, ADS1015_CONFIG, config); |
105 | if (res < 0) | |
106 | goto err_unlock; | |
c0046867 DE |
107 | |
108 | /* wait until conversion finished */ | |
109 | msleep(conversion_time_ms); | |
110 | res = ads1015_read_reg(client, ADS1015_CONFIG); | |
111 | if (res < 0) | |
112 | goto err_unlock; | |
113 | config = res; | |
114 | if (!(config & (1 << 15))) { | |
115 | /* conversion not finished in time */ | |
8c22a8f5 DE |
116 | res = -EIO; |
117 | goto err_unlock; | |
118 | } | |
119 | ||
120 | res = ads1015_read_reg(client, ADS1015_CONVERSION); | |
121 | if (res < 0) | |
122 | goto err_unlock; | |
123 | conversion = res; | |
124 | ||
125 | mutex_unlock(&data->update_lock); | |
126 | ||
127 | *value = DIV_ROUND_CLOSEST(conversion * fullscale, 0x7ff0); | |
128 | ||
129 | return 0; | |
130 | ||
131 | err_unlock: | |
132 | mutex_unlock(&data->update_lock); | |
133 | return res; | |
134 | } | |
135 | ||
136 | /* sysfs callback function */ | |
137 | static ssize_t show_in(struct device *dev, struct device_attribute *da, | |
138 | char *buf) | |
139 | { | |
140 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
141 | struct i2c_client *client = to_i2c_client(dev); | |
142 | int in; | |
143 | int res; | |
144 | ||
145 | res = ads1015_read_value(client, attr->index, &in); | |
146 | ||
147 | return (res < 0) ? res : sprintf(buf, "%d\n", in); | |
148 | } | |
149 | ||
fdf241a8 JD |
150 | static 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), | |
8c22a8f5 DE |
159 | }; |
160 | ||
161 | /* | |
162 | * Driver interface | |
163 | */ | |
164 | ||
165 | static int ads1015_remove(struct i2c_client *client) | |
166 | { | |
167 | struct ads1015_data *data = i2c_get_clientdata(client); | |
fdf241a8 JD |
168 | int k; |
169 | ||
8c22a8f5 | 170 | hwmon_device_unregister(data->hwmon_dev); |
c0046867 | 171 | for (k = 0; k < ADS1015_CHANNELS; ++k) |
fdf241a8 | 172 | device_remove_file(&client->dev, &ads1015_in[k].dev_attr); |
8c22a8f5 DE |
173 | kfree(data); |
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) { | |
188 | const __be32 *property; | |
189 | int len; | |
190 | unsigned int channel; | |
191 | unsigned int pga = ADS1015_DEFAULT_PGA; | |
192 | unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE; | |
193 | ||
194 | property = of_get_property(node, "reg", &len); | |
195 | if (!property || len != sizeof(int)) { | |
196 | dev_err(&client->dev, "invalid reg on %s\n", | |
197 | node->full_name); | |
198 | continue; | |
199 | } | |
200 | ||
201 | channel = be32_to_cpup(property); | |
202 | if (channel > ADS1015_CHANNELS) { | |
203 | dev_err(&client->dev, | |
204 | "invalid channel index %d on %s\n", | |
205 | channel, node->full_name); | |
206 | continue; | |
207 | } | |
208 | ||
209 | property = of_get_property(node, "ti,gain", &len); | |
210 | if (property && len == sizeof(int)) { | |
211 | pga = be32_to_cpup(property); | |
212 | if (pga > 6) { | |
213 | dev_err(&client->dev, | |
214 | "invalid gain on %s\n", | |
215 | node->full_name); | |
216 | } | |
217 | } | |
218 | ||
219 | property = of_get_property(node, "ti,datarate", &len); | |
220 | if (property && len == sizeof(int)) { | |
221 | data_rate = be32_to_cpup(property); | |
222 | if (data_rate > 7) { | |
223 | dev_err(&client->dev, | |
224 | "invalid data_rate on %s\n", | |
225 | node->full_name); | |
226 | } | |
227 | } | |
228 | ||
229 | data->channel_data[channel].enabled = true; | |
230 | data->channel_data[channel].pga = pga; | |
231 | data->channel_data[channel].data_rate = data_rate; | |
232 | } | |
233 | ||
234 | return 0; | |
235 | } | |
8c22a8f5 DE |
236 | #endif |
237 | ||
c0046867 DE |
238 | static void ads1015_get_channels_config(struct i2c_client *client) |
239 | { | |
240 | unsigned int k; | |
241 | struct ads1015_data *data = i2c_get_clientdata(client); | |
242 | struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev); | |
243 | ||
8c22a8f5 | 244 | /* prefer platform data */ |
c0046867 DE |
245 | if (pdata) { |
246 | memcpy(data->channel_data, pdata->channel_data, | |
247 | sizeof(data->channel_data)); | |
248 | return; | |
249 | } | |
8c22a8f5 DE |
250 | |
251 | #ifdef CONFIG_OF | |
c0046867 DE |
252 | if (!ads1015_get_channels_config_of(client)) |
253 | return; | |
8c22a8f5 DE |
254 | #endif |
255 | ||
256 | /* fallback on default configuration */ | |
c0046867 DE |
257 | for (k = 0; k < ADS1015_CHANNELS; ++k) { |
258 | data->channel_data[k].enabled = true; | |
259 | data->channel_data[k].pga = ADS1015_DEFAULT_PGA; | |
260 | data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE; | |
261 | } | |
8c22a8f5 DE |
262 | } |
263 | ||
264 | static int ads1015_probe(struct i2c_client *client, | |
265 | const struct i2c_device_id *id) | |
266 | { | |
267 | struct ads1015_data *data; | |
268 | int err; | |
8c22a8f5 | 269 | unsigned int k; |
8c22a8f5 DE |
270 | |
271 | data = kzalloc(sizeof(struct ads1015_data), GFP_KERNEL); | |
272 | if (!data) { | |
273 | err = -ENOMEM; | |
274 | goto exit; | |
275 | } | |
276 | ||
277 | i2c_set_clientdata(client, data); | |
278 | mutex_init(&data->update_lock); | |
279 | ||
280 | /* build sysfs attribute group */ | |
c0046867 DE |
281 | ads1015_get_channels_config(client); |
282 | for (k = 0; k < ADS1015_CHANNELS; ++k) { | |
283 | if (!data->channel_data[k].enabled) | |
8c22a8f5 | 284 | continue; |
fdf241a8 JD |
285 | err = device_create_file(&client->dev, &ads1015_in[k].dev_attr); |
286 | if (err) | |
287 | goto exit_free; | |
8c22a8f5 | 288 | } |
8c22a8f5 DE |
289 | |
290 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
291 | if (IS_ERR(data->hwmon_dev)) { | |
292 | err = PTR_ERR(data->hwmon_dev); | |
293 | goto exit_remove; | |
294 | } | |
295 | ||
296 | return 0; | |
297 | ||
298 | exit_remove: | |
c0046867 | 299 | for (k = 0; k < ADS1015_CHANNELS; ++k) |
fdf241a8 | 300 | device_remove_file(&client->dev, &ads1015_in[k].dev_attr); |
8c22a8f5 DE |
301 | exit_free: |
302 | kfree(data); | |
303 | exit: | |
304 | return err; | |
305 | } | |
306 | ||
307 | static const struct i2c_device_id ads1015_id[] = { | |
308 | { "ads1015", 0 }, | |
309 | { } | |
310 | }; | |
311 | MODULE_DEVICE_TABLE(i2c, ads1015_id); | |
312 | ||
313 | static struct i2c_driver ads1015_driver = { | |
314 | .driver = { | |
315 | .name = "ads1015", | |
316 | }, | |
317 | .probe = ads1015_probe, | |
318 | .remove = ads1015_remove, | |
319 | .id_table = ads1015_id, | |
320 | }; | |
321 | ||
322 | static int __init sensors_ads1015_init(void) | |
323 | { | |
324 | return i2c_add_driver(&ads1015_driver); | |
325 | } | |
326 | ||
327 | static void __exit sensors_ads1015_exit(void) | |
328 | { | |
329 | i2c_del_driver(&ads1015_driver); | |
330 | } | |
331 | ||
332 | MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>"); | |
333 | MODULE_DESCRIPTION("ADS1015 driver"); | |
334 | MODULE_LICENSE("GPL"); | |
335 | ||
336 | module_init(sensors_ads1015_init); | |
337 | module_exit(sensors_ads1015_exit); |