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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>
22#include <linux/of.h>
23
24#include <linux/platform_data/ads1015.h>
25
26
27enum {
28 ADS1015_CONVERSION = 0,
29 ADS1015_CONFIG = 1,
30};
31
32
33static const unsigned int fullscale_table[8] = {
34 6144, 4096, 2048, 1024, 512, 256, 256, 256 };
35
36
37static const unsigned int data_rate_table_1015[8] = {
38 128, 250, 490, 920, 1600, 2400, 3300, 3300
39};
40
41static const unsigned int data_rate_table_1115[8] = {
42 8, 16, 32, 64, 128, 250, 475, 860
43};
44
45#define ADS1015_DEFAULT_CHANNELS 0xff
46#define ADS1015_DEFAULT_PGA 2
47#define ADS1015_DEFAULT_DATA_RATE 4
48
49enum ads1015_chips {
50 ads1015,
51 ads1115,
52};
53
54struct ads1015_data {
55 struct device *hwmon_dev;
56 struct mutex update_lock;
57 struct ads1015_channel_data channel_data[ADS1015_CHANNELS];
58 enum ads1015_chips id;
59};
60
61static int ads1015_read_adc(struct i2c_client *client, unsigned int channel)
62{
63 u16 config;
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;
70 int res;
71
72 mutex_lock(&data->update_lock);
73
74
75 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
76 if (res < 0)
77 goto err_unlock;
78 config = res;
79 conversion_time_ms = DIV_ROUND_UP(1000, rate_table[data_rate]);
80
81
82 config &= 0x001f;
83 config |= (1 << 15) | (1 << 8);
84 config |= (channel & 0x0007) << 12;
85 config |= (pga & 0x0007) << 9;
86 config |= (data_rate & 0x0007) << 5;
87
88 res = i2c_smbus_write_word_swapped(client, ADS1015_CONFIG, config);
89 if (res < 0)
90 goto err_unlock;
91
92
93 msleep(conversion_time_ms);
94 res = i2c_smbus_read_word_swapped(client, ADS1015_CONFIG);
95 if (res < 0)
96 goto err_unlock;
97 config = res;
98 if (!(config & (1 << 15))) {
99
100 res = -EIO;
101 goto err_unlock;
102 }
103
104 res = i2c_smbus_read_word_swapped(client, ADS1015_CONVERSION);
105
106err_unlock:
107 mutex_unlock(&data->update_lock);
108 return res;
109}
110
111static int ads1015_reg_to_mv(struct i2c_client *client, unsigned int channel,
112 s16 reg)
113{
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;
118
119 return DIV_ROUND_CLOSEST(reg * fullscale, mask);
120}
121
122
123static ssize_t in_show(struct device *dev, struct device_attribute *da,
124 char *buf)
125{
126 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
127 struct i2c_client *client = to_i2c_client(dev);
128 int res;
129 int index = attr->index;
130
131 res = ads1015_read_adc(client, index);
132 if (res < 0)
133 return res;
134
135 return sprintf(buf, "%d\n", ads1015_reg_to_mv(client, index, res));
136}
137
138static 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),
147};
148
149
150
151
152
153static int ads1015_remove(struct i2c_client *client)
154{
155 struct ads1015_data *data = i2c_get_clientdata(client);
156 int k;
157
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);
161 return 0;
162}
163
164#ifdef CONFIG_OF
165static int ads1015_get_channels_config_of(struct i2c_client *client)
166{
167 struct ads1015_data *data = i2c_get_clientdata(client);
168 struct device_node *node;
169
170 if (!client->dev.of_node
171 || !of_get_next_child(client->dev.of_node, NULL))
172 return -EINVAL;
173
174 for_each_child_of_node(client->dev.of_node, node) {
175 u32 pval;
176 unsigned int channel;
177 unsigned int pga = ADS1015_DEFAULT_PGA;
178 unsigned int data_rate = ADS1015_DEFAULT_DATA_RATE;
179
180 if (of_property_read_u32(node, "reg", &pval)) {
181 dev_err(&client->dev, "invalid reg on %pOF\n", node);
182 continue;
183 }
184
185 channel = pval;
186 if (channel >= ADS1015_CHANNELS) {
187 dev_err(&client->dev,
188 "invalid channel index %d on %pOF\n",
189 channel, node);
190 continue;
191 }
192
193 if (!of_property_read_u32(node, "ti,gain", &pval)) {
194 pga = pval;
195 if (pga > 6) {
196 dev_err(&client->dev, "invalid gain on %pOF\n",
197 node);
198 return -EINVAL;
199 }
200 }
201
202 if (!of_property_read_u32(node, "ti,datarate", &pval)) {
203 data_rate = pval;
204 if (data_rate > 7) {
205 dev_err(&client->dev,
206 "invalid data_rate on %pOF\n", node);
207 return -EINVAL;
208 }
209 }
210
211 data->channel_data[channel].enabled = true;
212 data->channel_data[channel].pga = pga;
213 data->channel_data[channel].data_rate = data_rate;
214 }
215
216 return 0;
217}
218#endif
219
220static void ads1015_get_channels_config(struct i2c_client *client)
221{
222 unsigned int k;
223 struct ads1015_data *data = i2c_get_clientdata(client);
224 struct ads1015_platform_data *pdata = dev_get_platdata(&client->dev);
225
226
227 if (pdata) {
228 memcpy(data->channel_data, pdata->channel_data,
229 sizeof(data->channel_data));
230 return;
231 }
232
233#ifdef CONFIG_OF
234 if (!ads1015_get_channels_config_of(client))
235 return;
236#endif
237
238
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;
243 }
244}
245
246static int ads1015_probe(struct i2c_client *client,
247 const struct i2c_device_id *id)
248{
249 struct ads1015_data *data;
250 int err;
251 unsigned int k;
252
253 data = devm_kzalloc(&client->dev, sizeof(struct ads1015_data),
254 GFP_KERNEL);
255 if (!data)
256 return -ENOMEM;
257
258 if (client->dev.of_node)
259 data->id = (enum ads1015_chips)
260 of_device_get_match_data(&client->dev);
261 else
262 data->id = id->driver_data;
263 i2c_set_clientdata(client, data);
264 mutex_init(&data->update_lock);
265
266
267 ads1015_get_channels_config(client);
268 for (k = 0; k < ADS1015_CHANNELS; ++k) {
269 if (!data->channel_data[k].enabled)
270 continue;
271 err = device_create_file(&client->dev, &ads1015_in[k].dev_attr);
272 if (err)
273 goto exit_remove;
274 }
275
276 data->hwmon_dev = hwmon_device_register(&client->dev);
277 if (IS_ERR(data->hwmon_dev)) {
278 err = PTR_ERR(data->hwmon_dev);
279 goto exit_remove;
280 }
281
282 return 0;
283
284exit_remove:
285 for (k = 0; k < ADS1015_CHANNELS; ++k)
286 device_remove_file(&client->dev, &ads1015_in[k].dev_attr);
287 return err;
288}
289
290static const struct i2c_device_id ads1015_id[] = {
291 { "ads1015", ads1015},
292 { "ads1115", ads1115},
293 { }
294};
295MODULE_DEVICE_TABLE(i2c, ads1015_id);
296
297static const struct of_device_id __maybe_unused ads1015_of_match[] = {
298 {
299 .compatible = "ti,ads1015",
300 .data = (void *)ads1015
301 },
302 {
303 .compatible = "ti,ads1115",
304 .data = (void *)ads1115
305 },
306 { },
307};
308MODULE_DEVICE_TABLE(of, ads1015_of_match);
309
310static struct i2c_driver ads1015_driver = {
311 .driver = {
312 .name = "ads1015",
313 .of_match_table = of_match_ptr(ads1015_of_match),
314 },
315 .probe = ads1015_probe,
316 .remove = ads1015_remove,
317 .id_table = ads1015_id,
318};
319
320module_i2c_driver(ads1015_driver);
321
322MODULE_AUTHOR("Dirk Eibach <eibach@gdsys.de>");
323MODULE_DESCRIPTION("ADS1015 driver");
324MODULE_LICENSE("GPL");
325
