1/*
2 * Driver for Linear Technology LTC2990 power monitor
3 *
4 * Copyright (C) 2014 Topic Embedded Products
5 * Author: Mike Looijmans <mike.looijmans@topic.nl>
6 *
7 * License: GPLv2
8 */
9
10#include <linux/bitops.h>
11#include <linux/err.h>
12#include <linux/hwmon.h>
13#include <linux/hwmon-sysfs.h>
14#include <linux/i2c.h>
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/of.h>
18
19#define LTC2990_STATUS 0x00
20#define LTC2990_CONTROL 0x01
21#define LTC2990_TRIGGER 0x02
22#define LTC2990_TINT_MSB 0x04
23#define LTC2990_V1_MSB 0x06
24#define LTC2990_V2_MSB 0x08
25#define LTC2990_V3_MSB 0x0A
26#define LTC2990_V4_MSB 0x0C
27#define LTC2990_VCC_MSB 0x0E
28
29#define LTC2990_IN0 BIT(0)
30#define LTC2990_IN1 BIT(1)
31#define LTC2990_IN2 BIT(2)
32#define LTC2990_IN3 BIT(3)
33#define LTC2990_IN4 BIT(4)
34#define LTC2990_CURR1 BIT(5)
35#define LTC2990_CURR2 BIT(6)
36#define LTC2990_TEMP1 BIT(7)
37#define LTC2990_TEMP2 BIT(8)
38#define LTC2990_TEMP3 BIT(9)
39#define LTC2990_NONE 0
40#define LTC2990_ALL GENMASK(9, 0)
41
42#define LTC2990_MODE0_SHIFT 0
43#define LTC2990_MODE0_MASK GENMASK(2, 0)
44#define LTC2990_MODE1_SHIFT 3
45#define LTC2990_MODE1_MASK GENMASK(1, 0)
46
47/* Enabled measurements for mode bits 2..0 */
48static const int ltc2990_attrs_ena_0[] = {
49 LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
50 LTC2990_CURR1 | LTC2990_TEMP3,
51 LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
52 LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
53 LTC2990_TEMP2 | LTC2990_CURR2,
54 LTC2990_TEMP2 | LTC2990_TEMP3,
55 LTC2990_CURR1 | LTC2990_CURR2,
56 LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
57};
58
59/* Enabled measurements for mode bits 4..3 */
60static const int ltc2990_attrs_ena_1[] = {
61 LTC2990_NONE,
62 LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
63 LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
64 LTC2990_ALL
65};
66
67struct ltc2990_data {
68 struct i2c_client *i2c;
69 u32 mode[2];
70};
71
72/* Return the converted value from the given register in uV or mC */
73static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
74{
75 int val;
76 u8 reg;
77
78 switch (index) {
79 case LTC2990_IN0:
80 reg = LTC2990_VCC_MSB;
81 break;
82 case LTC2990_IN1:
83 case LTC2990_CURR1:
84 case LTC2990_TEMP2:
85 reg = LTC2990_V1_MSB;
86 break;
87 case LTC2990_IN2:
88 reg = LTC2990_V2_MSB;
89 break;
90 case LTC2990_IN3:
91 case LTC2990_CURR2:
92 case LTC2990_TEMP3:
93 reg = LTC2990_V3_MSB;
94 break;
95 case LTC2990_IN4:
96 reg = LTC2990_V4_MSB;
97 break;
98 case LTC2990_TEMP1:
99 reg = LTC2990_TINT_MSB;
100 break;
101 default:
102 return -EINVAL;
103 }
104
105 val = i2c_smbus_read_word_swapped(i2c, reg);
106 if (unlikely(val < 0))
107 return val;
108
109 switch (index) {
110 case LTC2990_TEMP1:
111 case LTC2990_TEMP2:
112 case LTC2990_TEMP3:
113 /* temp, 0.0625 degrees/LSB */
114 *result = sign_extend32(val, 12) * 1000 / 16;
115 break;
116 case LTC2990_CURR1:
117 case LTC2990_CURR2:
118 /* Vx-Vy, 19.42uV/LSB */
119 *result = sign_extend32(val, 14) * 1942 / 100;
120 break;
121 case LTC2990_IN0:
122 /* Vcc, 305.18uV/LSB, 2.5V offset */
123 *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
124 break;
125 case LTC2990_IN1:
126 case LTC2990_IN2:
127 case LTC2990_IN3:
128 case LTC2990_IN4:
129 /* Vx, 305.18uV/LSB */
130 *result = sign_extend32(val, 14) * 30518 / (100 * 1000);
131 break;
132 default:
133 return -EINVAL; /* won't happen, keep compiler happy */
134 }
135
136 return 0;
137}
138
139static ssize_t ltc2990_value_show(struct device *dev,
140 struct device_attribute *da, char *buf)
141{
142 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
143 struct ltc2990_data *data = dev_get_drvdata(dev);
144 int value;
145 int ret;
146
147 ret = ltc2990_get_value(data->i2c, attr->index, &value);
148 if (unlikely(ret < 0))
149 return ret;
150
151 return snprintf(buf, PAGE_SIZE, "%d\n", value);
152}
153
154static umode_t ltc2990_attrs_visible(struct kobject *kobj,
155 struct attribute *a, int n)
156{
157 struct device *dev = container_of(kobj, struct device, kobj);
158 struct ltc2990_data *data = dev_get_drvdata(dev);
159 struct device_attribute *da =
160 container_of(a, struct device_attribute, attr);
161 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
162
163 int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
164 (ltc2990_attrs_ena_0[data->mode[0]] &
165 ltc2990_attrs_ena_1[data->mode[1]]);
166
167 if (attr->index & attrs_mask)
168 return a->mode;
169
170 return 0;
171}
172
173static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
174static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
175static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
176static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
177static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
178static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
179static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
180static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
181static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
182static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
183
184static struct attribute *ltc2990_attrs[] = {
185 &sensor_dev_attr_temp1_input.dev_attr.attr,
186 &sensor_dev_attr_temp2_input.dev_attr.attr,
187 &sensor_dev_attr_temp3_input.dev_attr.attr,
188 &sensor_dev_attr_curr1_input.dev_attr.attr,
189 &sensor_dev_attr_curr2_input.dev_attr.attr,
190 &sensor_dev_attr_in0_input.dev_attr.attr,
191 &sensor_dev_attr_in1_input.dev_attr.attr,
192 &sensor_dev_attr_in2_input.dev_attr.attr,
193 &sensor_dev_attr_in3_input.dev_attr.attr,
194 &sensor_dev_attr_in4_input.dev_attr.attr,
195 NULL,
196};
197
198static const struct attribute_group ltc2990_group = {
199 .attrs = ltc2990_attrs,
200 .is_visible = ltc2990_attrs_visible,
201};
202__ATTRIBUTE_GROUPS(ltc2990);
203
204static int ltc2990_i2c_probe(struct i2c_client *i2c,
205 const struct i2c_device_id *id)
206{
207 int ret;
208 struct device *hwmon_dev;
209 struct ltc2990_data *data;
210 struct device_node *of_node = i2c->dev.of_node;
211
212 if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
213 I2C_FUNC_SMBUS_WORD_DATA))
214 return -ENODEV;
215
216 data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
217 if (unlikely(!data))
218 return -ENOMEM;
219
220 data->i2c = i2c;
221
222 if (of_node) {
223 ret = of_property_read_u32_array(of_node, "lltc,meas-mode",
224 data->mode, 2);
225 if (ret < 0)
226 return ret;
227
228 if (data->mode[0] & ~LTC2990_MODE0_MASK ||
229 data->mode[1] & ~LTC2990_MODE1_MASK)
230 return -EINVAL;
231 } else {
232 ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
233 if (ret < 0)
234 return ret;
235
236 data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
237 data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
238 }
239
240 /* Setup continuous mode */
241 ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
242 data->mode[0] << LTC2990_MODE0_SHIFT |
243 data->mode[1] << LTC2990_MODE1_SHIFT);
244 if (ret < 0) {
245 dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
246 return ret;
247 }
248 /* Trigger once to start continuous conversion */
249 ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
250 if (ret < 0) {
251 dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
252 return ret;
253 }
254
255 hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
256 i2c->name,
257 data,
258 ltc2990_groups);
259
260 return PTR_ERR_OR_ZERO(hwmon_dev);
261}
262
263static const struct i2c_device_id ltc2990_i2c_id[] = {
264 { "ltc2990", 0 },
265 {}
266};
267MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
268
269static struct i2c_driver ltc2990_i2c_driver = {
270 .driver = {
271 .name = "ltc2990",
272 },
273 .probe = ltc2990_i2c_probe,
274 .id_table = ltc2990_i2c_id,
275};
276
277module_i2c_driver(ltc2990_i2c_driver);
278
279MODULE_DESCRIPTION("LTC2990 Sensor Driver");
280MODULE_AUTHOR("Topic Embedded Products");
281MODULE_LICENSE("GPL v2");
282