treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / drivers / hwmon / ltc4222.c
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Driver for Linear Technology LTC4222 Dual Hot Swap controller
4  *
5  * Copyright (c) 2014 Guenter Roeck
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/err.h>
11 #include <linux/slab.h>
12 #include <linux/bitops.h>
13 #include <linux/i2c.h>
14 #include <linux/hwmon.h>
15 #include <linux/hwmon-sysfs.h>
16 #include <linux/jiffies.h>
17 #include <linux/regmap.h>
18
19 /* chip registers */
20
21 #define LTC4222_CONTROL1        0xd0
22 #define LTC4222_ALERT1          0xd1
23 #define LTC4222_STATUS1         0xd2
24 #define LTC4222_FAULT1          0xd3
25 #define LTC4222_CONTROL2        0xd4
26 #define LTC4222_ALERT2          0xd5
27 #define LTC4222_STATUS2         0xd6
28 #define LTC4222_FAULT2          0xd7
29 #define LTC4222_SOURCE1         0xd8
30 #define LTC4222_SOURCE2         0xda
31 #define LTC4222_ADIN1           0xdc
32 #define LTC4222_ADIN2           0xde
33 #define LTC4222_SENSE1          0xe0
34 #define LTC4222_SENSE2          0xe2
35 #define LTC4222_ADC_CONTROL     0xe4
36
37 /*
38  * Fault register bits
39  */
40 #define FAULT_OV        BIT(0)
41 #define FAULT_UV        BIT(1)
42 #define FAULT_OC        BIT(2)
43 #define FAULT_POWER_BAD BIT(3)
44 #define FAULT_FET_BAD   BIT(5)
45
46 /* Return the voltage from the given register in mV or mA */
47 static int ltc4222_get_value(struct device *dev, u8 reg)
48 {
49         struct regmap *regmap = dev_get_drvdata(dev);
50         unsigned int val;
51         u8 buf[2];
52         int ret;
53
54         ret = regmap_bulk_read(regmap, reg, buf, 2);
55         if (ret < 0)
56                 return ret;
57
58         val = ((buf[0] << 8) + buf[1]) >> 6;
59
60         switch (reg) {
61         case LTC4222_ADIN1:
62         case LTC4222_ADIN2:
63                 /* 1.25 mV resolution. Convert to mV. */
64                 val = DIV_ROUND_CLOSEST(val * 5, 4);
65                 break;
66         case LTC4222_SOURCE1:
67         case LTC4222_SOURCE2:
68                 /* 31.25 mV resolution. Convert to mV. */
69                 val = DIV_ROUND_CLOSEST(val * 125, 4);
70                 break;
71         case LTC4222_SENSE1:
72         case LTC4222_SENSE2:
73                 /*
74                  * 62.5 uV resolution. Convert to current as measured with
75                  * an 1 mOhm sense resistor, in mA. If a different sense
76                  * resistor is installed, calculate the actual current by
77                  * dividing the reported current by the sense resistor value
78                  * in mOhm.
79                  */
80                 val = DIV_ROUND_CLOSEST(val * 125, 2);
81                 break;
82         default:
83                 return -EINVAL;
84         }
85         return val;
86 }
87
88 static ssize_t ltc4222_value_show(struct device *dev,
89                                   struct device_attribute *da, char *buf)
90 {
91         struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
92         int value;
93
94         value = ltc4222_get_value(dev, attr->index);
95         if (value < 0)
96                 return value;
97         return snprintf(buf, PAGE_SIZE, "%d\n", value);
98 }
99
100 static ssize_t ltc4222_bool_show(struct device *dev,
101                                  struct device_attribute *da, char *buf)
102 {
103         struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
104         struct regmap *regmap = dev_get_drvdata(dev);
105         unsigned int fault;
106         int ret;
107
108         ret = regmap_read(regmap, attr->nr, &fault);
109         if (ret < 0)
110                 return ret;
111         fault &= attr->index;
112         if (fault)              /* Clear reported faults in chip register */
113                 regmap_update_bits(regmap, attr->nr, attr->index, 0);
114
115         return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
116 }
117
118 /* Voltages */
119 static SENSOR_DEVICE_ATTR_RO(in1_input, ltc4222_value, LTC4222_SOURCE1);
120 static SENSOR_DEVICE_ATTR_RO(in2_input, ltc4222_value, LTC4222_ADIN1);
121 static SENSOR_DEVICE_ATTR_RO(in3_input, ltc4222_value, LTC4222_SOURCE2);
122 static SENSOR_DEVICE_ATTR_RO(in4_input, ltc4222_value, LTC4222_ADIN2);
123
124 /*
125  * Voltage alarms
126  * UV/OV faults are associated with the input voltage, and power bad and fet
127  * faults are associated with the output voltage.
128  */
129 static SENSOR_DEVICE_ATTR_2_RO(in1_min_alarm, ltc4222_bool, LTC4222_FAULT1,
130                                FAULT_UV);
131 static SENSOR_DEVICE_ATTR_2_RO(in1_max_alarm, ltc4222_bool, LTC4222_FAULT1,
132                                FAULT_OV);
133 static SENSOR_DEVICE_ATTR_2_RO(in2_alarm, ltc4222_bool, LTC4222_FAULT1,
134                                FAULT_POWER_BAD | FAULT_FET_BAD);
135
136 static SENSOR_DEVICE_ATTR_2_RO(in3_min_alarm, ltc4222_bool, LTC4222_FAULT2,
137                                FAULT_UV);
138 static SENSOR_DEVICE_ATTR_2_RO(in3_max_alarm, ltc4222_bool, LTC4222_FAULT2,
139                                FAULT_OV);
140 static SENSOR_DEVICE_ATTR_2_RO(in4_alarm, ltc4222_bool, LTC4222_FAULT2,
141                                FAULT_POWER_BAD | FAULT_FET_BAD);
142
143 /* Current (via sense resistor) */
144 static SENSOR_DEVICE_ATTR_RO(curr1_input, ltc4222_value, LTC4222_SENSE1);
145 static SENSOR_DEVICE_ATTR_RO(curr2_input, ltc4222_value, LTC4222_SENSE2);
146
147 /* Overcurrent alarm */
148 static SENSOR_DEVICE_ATTR_2_RO(curr1_max_alarm, ltc4222_bool, LTC4222_FAULT1,
149                                FAULT_OC);
150 static SENSOR_DEVICE_ATTR_2_RO(curr2_max_alarm, ltc4222_bool, LTC4222_FAULT2,
151                                FAULT_OC);
152
153 static struct attribute *ltc4222_attrs[] = {
154         &sensor_dev_attr_in1_input.dev_attr.attr,
155         &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
156         &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
157         &sensor_dev_attr_in2_input.dev_attr.attr,
158         &sensor_dev_attr_in2_alarm.dev_attr.attr,
159         &sensor_dev_attr_in3_input.dev_attr.attr,
160         &sensor_dev_attr_in3_min_alarm.dev_attr.attr,
161         &sensor_dev_attr_in3_max_alarm.dev_attr.attr,
162         &sensor_dev_attr_in4_input.dev_attr.attr,
163         &sensor_dev_attr_in4_alarm.dev_attr.attr,
164
165         &sensor_dev_attr_curr1_input.dev_attr.attr,
166         &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
167         &sensor_dev_attr_curr2_input.dev_attr.attr,
168         &sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
169
170         NULL,
171 };
172 ATTRIBUTE_GROUPS(ltc4222);
173
174 static const struct regmap_config ltc4222_regmap_config = {
175         .reg_bits = 8,
176         .val_bits = 8,
177         .max_register = LTC4222_ADC_CONTROL,
178 };
179
180 static int ltc4222_probe(struct i2c_client *client,
181                          const struct i2c_device_id *id)
182 {
183         struct device *dev = &client->dev;
184         struct device *hwmon_dev;
185         struct regmap *regmap;
186
187         regmap = devm_regmap_init_i2c(client, &ltc4222_regmap_config);
188         if (IS_ERR(regmap)) {
189                 dev_err(dev, "failed to allocate register map\n");
190                 return PTR_ERR(regmap);
191         }
192
193         /* Clear faults */
194         regmap_write(regmap, LTC4222_FAULT1, 0x00);
195         regmap_write(regmap, LTC4222_FAULT2, 0x00);
196
197         hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
198                                                            regmap,
199                                                            ltc4222_groups);
200         return PTR_ERR_OR_ZERO(hwmon_dev);
201 }
202
203 static const struct i2c_device_id ltc4222_id[] = {
204         {"ltc4222", 0},
205         { }
206 };
207
208 MODULE_DEVICE_TABLE(i2c, ltc4222_id);
209
210 static struct i2c_driver ltc4222_driver = {
211         .driver = {
212                    .name = "ltc4222",
213                    },
214         .probe = ltc4222_probe,
215         .id_table = ltc4222_id,
216 };
217
218 module_i2c_driver(ltc4222_driver);
219
220 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
221 MODULE_DESCRIPTION("LTC4222 driver");
222 MODULE_LICENSE("GPL");