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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_device.h>
35#include <linux/of.h>
36
37#include <linux/platform_data/ads1015.h>
38
39
40enum {
41 ADS1015_CONVERSION = 0,
42 ADS1015_CONFIG = 1,
43};
44
45
46static const unsigned int fullscale_table[8] = {
47 6144, 4096, 2048, 1024, 512, 256, 256, 256 };
48
49
50static const unsigned int data_rate_table_1015[8] = {
51 128, 250, 490, 920, 1600, 2400, 3300, 3300
52};
53
54static const unsigned int data_rate_table_1115[8] = {
55 8, 16, 32, 64, 128, 250, 475, 860
56};
57
58#define ADS1015_DEFAULT_CHANNELS 0xff
59#define ADS1015_DEFAULT_PGA 2
60#define ADS1015_DEFAULT_DATA_RATE 4
61
62enum ads1015_chips {
63 ads1015,
64 ads1115,
65};
66
67struct ads1015_data {
68 struct device *hwmon_dev;
69 struct mutex update_lock;
70 struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
71 enum ads1015_chips id;
72};
73
74static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
75{
76 u16 config;
77 struct ads1015_data *data = i2c_get_clientdata(client);
78 unsigned int pga = data->channel_data[channel].pga;
79 unsigned int data_rate = data->channel_data[channel].data_rate;
80 unsigned int conversion_time_ms;
81 const unsigned int * const rate_table = data->id == ads1115 ?
82 data_rate_table_1115 : data_rate_table_1015;
83 int res;
84
85 mutex_lock(&data->update_lock);
86
87
88 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
89 if (res < 0)
90 goto err_unlock;
91 config = res;
92 conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
93
94
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;
100
101 res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
102 if (res < 0)
103 goto err_unlock;
104
105
106 msleep(conversion_time_ms);
107 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
108 if (res < 0)
109 goto err_unlock;
110 config = res;
111 if (!(config & (1 << 15))) {
112
113 res = -EIO;
114 goto err_unlock;
115 }
116
117 res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
118
119err_unlock:
120 mutex_unlock(&data->update_lock);
121 return res;
122}
123
124static 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];
130 const int mask = data->id == ads1115 ? 0x7fff : 0x7ff0;
131
132 return DIV_ROUND_CLOSEST(reg * fullscale, mask);
133}
134
135
136static 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);
141 int res;
142 int index = attr->index;
143
144 res = ads1015_read_adc(client, index);
145 if (res < 0)
146 return res;
147
148 return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
149}
150
151static 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),
160};
161
162
163
164
165
166static int ads1015_remove(struct i2c_client *client)
167{
168 struct ads1015_data *data = i2c_get_clientdata(client);
169 int k;
170
171 hwmon_device_unregister(data->hwmon_dev);
172 for (k = 0; k < ADS1015_CHANNELS; ++k)
173 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
174 return 0;
175}
176
177#ifdef CONFIG_OF
178static 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 u32 pval;
189 unsigned int channel;
190 unsigned int pga = ADS1015_DEFAULT_PGA;
191 unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
192
193 if (of_property_read_u32(node, "reg", &pval)) {
194 dev_err(&client->dev, "invalid reg on %s\n",
195 node->full_name);
196 continue;
197 }
198
199 channel = pval;
200 if (channel >= ADS1015_CHANNELS) {
201 dev_err(&client->dev,
202 "invalid channel index %d on %s\n",
203 channel, node->full_name);
204 continue;
205 }
206
207 if (!of_property_read_u32(node, "ti,gain", &pval)) {
208 pga = pval;
209 if (pga > 6) {
210 dev_err(&client->dev, "invalid gain on %s\n",
211 node->full_name);
212 return -EINVAL;
213 }
214 }
215
216 if (!of_property_read_u32(node, "ti,datarate", &pval)) {
217 data_rate = pval;
218 if (data_rate > 7) {
219 dev_err(&client->dev,
220 "invalid data_rate on %s\n",
221 node->full_name);
222 return -EINVAL;
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}
233#endif
234
235static 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
241
242 if (pdata) {
243 memcpy(data->channel_data, pdata->channel_data,
244 sizeof(data->channel_data));
245 return;
246 }
247
248#ifdef CONFIG_OF
249 if (!ads1015_get_channels_config_of(client))
250 return;
251#endif
252
253
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 }
259}
260
261static int ads1015_probe(struct i2c_client *client,
262 const struct i2c_device_id *id)
263{
264 struct ads1015_data *data;
265 int err;
266 unsigned int k;
267
268 data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
269 GFP_KERNEL);
270 if (!data)
271 return -ENOMEM;
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;
278 i2c_set_clientdata(client, data);
279 mutex_init(&data->update_lock);
280
281
282 ads1015_get_channels_config(client);
283 for (k = 0; k < ADS1015_CHANNELS; ++k) {
284 if (!data->channel_data[k].enabled)
285 continue;
286 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
287 if (err)
288 goto exit_remove;
289 }
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
299exit_remove:
300 for (k = 0; k < ADS1015_CHANNELS; ++k)
301 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
302 return err;
303}
304
305static const struct i2c_device_id ads1015_id[] = {
306 { "ads1015", ads1015},
307 { "ads1115", ads1115},
308 { }
309};
310MODULE_DEVICE_TABLE(i2c, ads1015_id);
311
312static 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};
323MODULE_DEVICE_TABLE(of, ads1015_of_match);
324
325static struct i2c_driver ads1015_driver = {
326 .driver = {
327 .name = "ads1015",
328 .of_match_table = of_match_ptr(ads1015_of_match),
329 },
330 .probe = ads1015_probe,
331 .remove = ads1015_remove,
332 .id_table = ads1015_id,
333};
334
335module_i2c_driver(ads1015_driver);
336
337MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
338MODULE_DESCRIPTION("ADS1015 driver");
339MODULE_LICENSE("GPL");
340
