1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * ads1015.c - lm_sensors driver for ads1015 12-bit 4-input ADC
5 * Dirk Eibach, Guntermann & Drunck GmbH <eibach@gdsys.de>
7 * Based on the ads7828 driver by Steve Hardy.
9 * Datasheet available at: http://focus.ti.com/lit/ds/symlink/ads1015.pdf
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/slab.h>
15 #include <linux/delay.h>
16 #include <linux/i2c.h>
17 #include <linux/hwmon.h>
18 #include <linux/hwmon-sysfs.h>
19 #include <linux/err.h>
20 #include <linux/mutex.h>
21 #include <linux/of_device.h>
24 #include <linux/platform_data/ads1015.h>
26 /* ADS1015 registers */
28 ADS1015_CONVERSION = 0,
32 /* PGA fullscale voltages in mV */
33 static const unsigned int fullscale_table[8] = {
34 6144, 4096, 2048, 1024, 512, 256, 256, 256 };
36 /* Data rates in samples per second */
37 static const unsigned int data_rate_table_1015[8] = {
38 128, 250, 490, 920, 1600, 2400, 3300, 3300
41 static const unsigned int data_rate_table_1115[8] = {
42 8, 16, 32, 64, 128, 250, 475, 860
45 #define ADS1015_DEFAULT_CHANNELS 0xff
46 #define ADS1015_DEFAULT_PGA 2
47 #define ADS1015_DEFAULT_DATA_RATE 4
55 struct device *hwmon_dev;
56 struct mutex update_lock; /* mutex protect updates */
57 struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
58 enum ads1015_chips id;
61 static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
64 struct ads1015_data *data = i2c_get_clientdata(client);
65 unsigned int pga = data->channel_data[channel].pga;
66 unsigned int data_rate = data->channel_data[channel].data_rate;
67 unsigned int conversion_time_ms;
68 const unsigned int * const rate_table = data->id == ads1115 ?
69 data_rate_table_1115 : data_rate_table_1015;
72 mutex_lock(&data->update_lock);
74 /* get channel parameters */
75 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
79 conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
81 /* setup and start single conversion */
83 config |= (1 << 15) | (1 << 8);
84 config |= (channel & 0x0007) << 12;
85 config |= (pga & 0x0007) << 9;
86 config |= (data_rate & 0x0007) << 5;
88 res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
92 /* wait until conversion finished */
93 msleep(conversion_time_ms);
94 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
98 if (!(config & (1 << 15))) {
99 /* conversion not finished in time */
104 res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
107 mutex_unlock(&data->update_lock);
111 static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
114 struct ads1015_data *data = i2c_get_clientdata(client);
115 unsigned int pga = data->channel_data[channel].pga;
116 int fullscale = fullscale_table[pga];
117 const int mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
119 return DIV_ROUND_CLOSEST(reg * fullscale, mask);
122 /* sysfs callback function */
123 static ssize_t in_show(struct device *dev, struct device_attribute *da,
126 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
127 struct i2c_client *client = to_i2c_client(dev);
129 int index = attr->index;
131 res = ads1015_read_adc(client, index);
135 return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
138 static const struct sensor_device_attribute ads1015_in[] = {
139 SENSOR_ATTR_RO(in0_input, in, 0),
140 SENSOR_ATTR_RO(in1_input, in, 1),
141 SENSOR_ATTR_RO(in2_input, in, 2),
142 SENSOR_ATTR_RO(in3_input, in, 3),
143 SENSOR_ATTR_RO(in4_input, in, 4),
144 SENSOR_ATTR_RO(in5_input, in, 5),
145 SENSOR_ATTR_RO(in6_input, in, 6),
146 SENSOR_ATTR_RO(in7_input, in, 7),
153 static int ads1015_remove(struct i2c_client *client)
155 struct ads1015_data *data = i2c_get_clientdata(client);
158 hwmon_device_unregister(data->hwmon_dev);
159 for (k = 0; k < ADS1015_CHANNELS; ++k)
160 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
165 static int ads1015_get_channels_config_of(struct i2c_client *client)
167 struct ads1015_data *data = i2c_get_clientdata(client);
168 struct device_node *node;
170 if (!client->dev.of_node
171 || !of_get_next_child(client->dev.of_node, NULL))
174 for_each_child_of_node(client->dev.of_node, node) {
176 unsigned int channel;
177 unsigned int pga = ADS1015_DEFAULT_PGA;
178 unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
180 if (of_property_read_u32(node, "reg", &pval)) {
181 dev_err(&client->dev, "invalid reg on %pOF\n", node);
186 if (channel >= ADS1015_CHANNELS) {
187 dev_err(&client->dev,
188 "invalid channel index %d on %pOF\n",
193 if (!of_property_read_u32(node, "ti,gain", &pval)) {
196 dev_err(&client->dev, "invalid gain on %pOF\n",
202 if (!of_property_read_u32(node, "ti,datarate", &pval)) {
205 dev_err(&client->dev,
206 "invalid data_rate on %pOF\n", node);
211 data->channel_data[channel].enabled = true;
212 data->channel_data[channel].pga = pga;
213 data->channel_data[channel].data_rate = data_rate;
220 static void ads1015_get_channels_config(struct i2c_client *client)
223 struct ads1015_data *data = i2c_get_clientdata(client);
224 struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
226 /* prefer platform data */
228 memcpy(data->channel_data, pdata->channel_data,
229 sizeof(data->channel_data));
234 if (!ads1015_get_channels_config_of(client))
238 /* fallback on default configuration */
239 for (k = 0; k < ADS1015_CHANNELS; ++k) {
240 data->channel_data[k].enabled = true;
241 data->channel_data[k].pga = ADS1015_DEFAULT_PGA;
242 data->channel_data[k].data_rate = ADS1015_DEFAULT_DATA_RATE;
246 static int ads1015_probe(struct i2c_client *client,
247 const struct i2c_device_id *id)
249 struct ads1015_data *data;
253 data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
258 if (client->dev.of_node)
259 data->id = (enum ads1015_chips)
260 of_device_get_match_data(&client->dev);
262 data->id = id->driver_data;
263 i2c_set_clientdata(client, data);
264 mutex_init(&data->update_lock);
266 /* build sysfs attribute group */
267 ads1015_get_channels_config(client);
268 for (k = 0; k < ADS1015_CHANNELS; ++k) {
269 if (!data->channel_data[k].enabled)
271 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
276 data->hwmon_dev = hwmon_device_register(&client->dev);
277 if (IS_ERR(data->hwmon_dev)) {
278 err = PTR_ERR(data->hwmon_dev);
285 for (k = 0; k < ADS1015_CHANNELS; ++k)
286 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
290 static const struct i2c_device_id ads1015_id[] = {
291 { "ads1015", ads1015},
292 { "ads1115", ads1115},
295 MODULE_DEVICE_TABLE(i2c, ads1015_id);
297 static const struct of_device_id __maybe_unused ads1015_of_match[] = {
299 .compatible = "ti,ads1015",
300 .data = (void *)ads1015
303 .compatible = "ti,ads1115",
304 .data = (void *)ads1115
308 MODULE_DEVICE_TABLE(of, ads1015_of_match);
310 static struct i2c_driver ads1015_driver = {
313 .of_match_table = of_match_ptr(ads1015_of_match),
315 .probe = ads1015_probe,
316 .remove = ads1015_remove,
317 .id_table = ads1015_id,
320 module_i2c_driver(ads1015_driver);
322 MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
323 MODULE_DESCRIPTION("ADS1015 driver");
324 MODULE_LICENSE("GPL");