xref: /openbmc/linux/drivers/hwmon/ltc2990.c (revision 1975d167)
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", 0 },
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