1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Driver for Linear Technology LTC2990 power monitor
4 *
5 * Copyright (C) 2014 Topic Embedded Products
6 * Author: Mike Looijmans <mike.looijmans@topic.nl>
7 */
8
9 #include <linux/bitops.h>
10 #include <linux/err.h>
11 #include <linux/hwmon.h>
12 #include <linux/hwmon-sysfs.h>
13 #include <linux/i2c.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/property.h>
17
18 #define LTC2990_STATUS 0x00
19 #define LTC2990_CONTROL 0x01
20 #define LTC2990_TRIGGER 0x02
21 #define LTC2990_TINT_MSB 0x04
22 #define LTC2990_V1_MSB 0x06
23 #define LTC2990_V2_MSB 0x08
24 #define LTC2990_V3_MSB 0x0A
25 #define LTC2990_V4_MSB 0x0C
26 #define LTC2990_VCC_MSB 0x0E
27
28 #define LTC2990_IN0 BIT(0)
29 #define LTC2990_IN1 BIT(1)
30 #define LTC2990_IN2 BIT(2)
31 #define LTC2990_IN3 BIT(3)
32 #define LTC2990_IN4 BIT(4)
33 #define LTC2990_CURR1 BIT(5)
34 #define LTC2990_CURR2 BIT(6)
35 #define LTC2990_TEMP1 BIT(7)
36 #define LTC2990_TEMP2 BIT(8)
37 #define LTC2990_TEMP3 BIT(9)
38 #define LTC2990_NONE 0
39 #define LTC2990_ALL GENMASK(9, 0)
40
41 #define LTC2990_MODE0_SHIFT 0
42 #define LTC2990_MODE0_MASK GENMASK(2, 0)
43 #define LTC2990_MODE1_SHIFT 3
44 #define LTC2990_MODE1_MASK GENMASK(1, 0)
45
46 /* Enabled measurements for mode bits 2..0 */
47 static const int ltc2990_attrs_ena_0[] = {
48 LTC2990_IN1 | LTC2990_IN2 | LTC2990_TEMP3,
49 LTC2990_CURR1 | LTC2990_TEMP3,
50 LTC2990_CURR1 | LTC2990_IN3 | LTC2990_IN4,
51 LTC2990_TEMP2 | LTC2990_IN3 | LTC2990_IN4,
52 LTC2990_TEMP2 | LTC2990_CURR2,
53 LTC2990_TEMP2 | LTC2990_TEMP3,
54 LTC2990_CURR1 | LTC2990_CURR2,
55 LTC2990_IN1 | LTC2990_IN2 | LTC2990_IN3 | LTC2990_IN4
56 };
57
58 /* Enabled measurements for mode bits 4..3 */
59 static const int ltc2990_attrs_ena_1[] = {
60 LTC2990_NONE,
61 LTC2990_TEMP2 | LTC2990_IN1 | LTC2990_CURR1,
62 LTC2990_TEMP3 | LTC2990_IN3 | LTC2990_CURR2,
63 LTC2990_ALL
64 };
65
66 struct ltc2990_data {
67 struct i2c_client *i2c;
68 u32 mode[2];
69 };
70
71 /* Return the converted value from the given register in uV or mC */
ltc2990_get_value(struct i2c_client * i2c,int index,int * result)72 static int ltc2990_get_value(struct i2c_client *i2c, int index, int *result)
73 {
74 int val;
75 u8 reg;
76
77 switch (index) {
78 case LTC2990_IN0:
79 reg = LTC2990_VCC_MSB;
80 break;
81 case LTC2990_IN1:
82 case LTC2990_CURR1:
83 case LTC2990_TEMP2:
84 reg = LTC2990_V1_MSB;
85 break;
86 case LTC2990_IN2:
87 reg = LTC2990_V2_MSB;
88 break;
89 case LTC2990_IN3:
90 case LTC2990_CURR2:
91 case LTC2990_TEMP3:
92 reg = LTC2990_V3_MSB;
93 break;
94 case LTC2990_IN4:
95 reg = LTC2990_V4_MSB;
96 break;
97 case LTC2990_TEMP1:
98 reg = LTC2990_TINT_MSB;
99 break;
100 default:
101 return -EINVAL;
102 }
103
104 val = i2c_smbus_read_word_swapped(i2c, reg);
105 if (unlikely(val < 0))
106 return val;
107
108 switch (index) {
109 case LTC2990_TEMP1:
110 case LTC2990_TEMP2:
111 case LTC2990_TEMP3:
112 /* temp, 0.0625 degrees/LSB */
113 *result = sign_extend32(val, 12) * 1000 / 16;
114 break;
115 case LTC2990_CURR1:
116 case LTC2990_CURR2:
117 /* Vx-Vy, 19.42uV/LSB */
118 *result = sign_extend32(val, 14) * 1942 / 100;
119 break;
120 case LTC2990_IN0:
121 /* Vcc, 305.18uV/LSB, 2.5V offset */
122 *result = sign_extend32(val, 14) * 30518 / (100 * 1000) + 2500;
123 break;
124 case LTC2990_IN1:
125 case LTC2990_IN2:
126 case LTC2990_IN3:
127 case LTC2990_IN4:
128 /* Vx, 305.18uV/LSB */
129 *result = sign_extend32(val, 14) * 30518 / (100 * 1000);
130 break;
131 default:
132 return -EINVAL; /* won't happen, keep compiler happy */
133 }
134
135 return 0;
136 }
137
ltc2990_value_show(struct device * dev,struct device_attribute * da,char * buf)138 static ssize_t ltc2990_value_show(struct device *dev,
139 struct device_attribute *da, char *buf)
140 {
141 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
142 struct ltc2990_data *data = dev_get_drvdata(dev);
143 int value;
144 int ret;
145
146 ret = ltc2990_get_value(data->i2c, attr->index, &value);
147 if (unlikely(ret < 0))
148 return ret;
149
150 return sysfs_emit(buf, "%d\n", value);
151 }
152
ltc2990_attrs_visible(struct kobject * kobj,struct attribute * a,int n)153 static umode_t ltc2990_attrs_visible(struct kobject *kobj,
154 struct attribute *a, int n)
155 {
156 struct device *dev = kobj_to_dev(kobj);
157 struct ltc2990_data *data = dev_get_drvdata(dev);
158 struct device_attribute *da =
159 container_of(a, struct device_attribute, attr);
160 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
161
162 int attrs_mask = LTC2990_IN0 | LTC2990_TEMP1 |
163 (ltc2990_attrs_ena_0[data->mode[0]] &
164 ltc2990_attrs_ena_1[data->mode[1]]);
165
166 if (attr->index & attrs_mask)
167 return a->mode;
168
169 return 0;
170 }
171
172 static SENSOR_DEVICE_ATTR_RO(temp1_input, ltc2990_value, LTC2990_TEMP1);
173 static SENSOR_DEVICE_ATTR_RO(temp2_input, ltc2990_value, LTC2990_TEMP2);
174 static SENSOR_DEVICE_ATTR_RO(temp3_input, ltc2990_value, LTC2990_TEMP3);
175 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc2990_value, LTC2990_CURR1);
176 static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc2990_value, LTC2990_CURR2);
177 static SENSOR_DEVICE_ATTR_RO(in0_input, ltc2990_value, LTC2990_IN0);
178 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc2990_value, LTC2990_IN1);
179 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc2990_value, LTC2990_IN2);
180 static SENSOR_DEVICE_ATTR_RO(in3_input, ltc2990_value, LTC2990_IN3);
181 static SENSOR_DEVICE_ATTR_RO(in4_input, ltc2990_value, LTC2990_IN4);
182
183 static struct attribute *ltc2990_attrs[] = {
184 &sensor_dev_attr_temp1_input.dev_attr.attr,
185 &sensor_dev_attr_temp2_input.dev_attr.attr,
186 &sensor_dev_attr_temp3_input.dev_attr.attr,
187 &sensor_dev_attr_curr1_input.dev_attr.attr,
188 &sensor_dev_attr_curr2_input.dev_attr.attr,
189 &sensor_dev_attr_in0_input.dev_attr.attr,
190 &sensor_dev_attr_in1_input.dev_attr.attr,
191 &sensor_dev_attr_in2_input.dev_attr.attr,
192 &sensor_dev_attr_in3_input.dev_attr.attr,
193 &sensor_dev_attr_in4_input.dev_attr.attr,
194 NULL,
195 };
196
197 static const struct attribute_group ltc2990_group = {
198 .attrs = ltc2990_attrs,
199 .is_visible = ltc2990_attrs_visible,
200 };
201 __ATTRIBUTE_GROUPS(ltc2990);
202
ltc2990_i2c_probe(struct i2c_client * i2c)203 static int ltc2990_i2c_probe(struct i2c_client *i2c)
204 {
205 int ret;
206 struct device *hwmon_dev;
207 struct ltc2990_data *data;
208
209 if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA |
210 I2C_FUNC_SMBUS_WORD_DATA))
211 return -ENODEV;
212
213 data = devm_kzalloc(&i2c->dev, sizeof(struct ltc2990_data), GFP_KERNEL);
214 if (unlikely(!data))
215 return -ENOMEM;
216
217 data->i2c = i2c;
218
219 if (dev_fwnode(&i2c->dev)) {
220 ret = device_property_read_u32_array(&i2c->dev,
221 "lltc,meas-mode",
222 data->mode, 2);
223 if (ret < 0)
224 return ret;
225
226 if (data->mode[0] & ~LTC2990_MODE0_MASK ||
227 data->mode[1] & ~LTC2990_MODE1_MASK)
228 return -EINVAL;
229 } else {
230 ret = i2c_smbus_read_byte_data(i2c, LTC2990_CONTROL);
231 if (ret < 0)
232 return ret;
233
234 data->mode[0] = ret >> LTC2990_MODE0_SHIFT & LTC2990_MODE0_MASK;
235 data->mode[1] = ret >> LTC2990_MODE1_SHIFT & LTC2990_MODE1_MASK;
236 }
237
238 /* Setup continuous mode */
239 ret = i2c_smbus_write_byte_data(i2c, LTC2990_CONTROL,
240 data->mode[0] << LTC2990_MODE0_SHIFT |
241 data->mode[1] << LTC2990_MODE1_SHIFT);
242 if (ret < 0) {
243 dev_err(&i2c->dev, "Error: Failed to set control mode.\n");
244 return ret;
245 }
246 /* Trigger once to start continuous conversion */
247 ret = i2c_smbus_write_byte_data(i2c, LTC2990_TRIGGER, 1);
248 if (ret < 0) {
249 dev_err(&i2c->dev, "Error: Failed to start acquisition.\n");
250 return ret;
251 }
252
253 hwmon_dev = devm_hwmon_device_register_with_groups(&i2c->dev,
254 i2c->name,
255 data,
256 ltc2990_groups);
257
258 return PTR_ERR_OR_ZERO(hwmon_dev);
259 }
260
261 static const struct i2c_device_id ltc2990_i2c_id[] = {
262 { "ltc2990" },
263 {}
264 };
265 MODULE_DEVICE_TABLE(i2c, ltc2990_i2c_id);
266
267 static struct i2c_driver ltc2990_i2c_driver = {
268 .driver = {
269 .name = "ltc2990",
270 },
271 .probe = ltc2990_i2c_probe,
272 .id_table = ltc2990_i2c_id,
273 };
274
275 module_i2c_driver(ltc2990_i2c_driver);
276
277 MODULE_DESCRIPTION("LTC2990 Sensor Driver");
278 MODULE_AUTHOR("Topic Embedded Products");
279 MODULE_LICENSE("GPL v2");
280