1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
|
// SPDX-License-Identifier: GPL-2.0
/*
* ADM1177 Hot Swap Controller and Digital Power Monitor with Soft Start Pin
*
* Copyright 2015-2019 Analog Devices Inc.
*/
#include <linux/bits.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
/* Command Byte Operations */
#define ADM1177_CMD_V_CONT BIT(0)
#define ADM1177_CMD_I_CONT BIT(2)
#define ADM1177_CMD_VRANGE BIT(4)
/* Extended Register */
#define ADM1177_REG_ALERT_TH 2
#define ADM1177_BITS 12
/**
* struct adm1177_state - driver instance specific data
* @client: pointer to i2c client
* @reg: regulator info for the power supply of the device
* @r_sense_uohm: current sense resistor value
* @alert_threshold_ua: current limit for shutdown
* @vrange_high: internal voltage divider
*/
struct adm1177_state {
struct i2c_client *client;
struct regulator *reg;
u32 r_sense_uohm;
u32 alert_threshold_ua;
bool vrange_high;
};
static int adm1177_read_raw(struct adm1177_state *st, u8 num, u8 *data)
{
return i2c_master_recv(st->client, data, num);
}
static int adm1177_write_cmd(struct adm1177_state *st, u8 cmd)
{
return i2c_smbus_write_byte(st->client, cmd);
}
static int adm1177_write_alert_thr(struct adm1177_state *st,
u32 alert_threshold_ua)
{
u64 val;
int ret;
val = 0xFFULL * alert_threshold_ua * st->r_sense_uohm;
val = div_u64(val, 105840000U);
val = div_u64(val, 1000U);
if (val > 0xFF)
val = 0xFF;
ret = i2c_smbus_write_byte_data(st->client, ADM1177_REG_ALERT_TH,
val);
if (ret)
return ret;
st->alert_threshold_ua = alert_threshold_ua;
return 0;
}
static int adm1177_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct adm1177_state *st = dev_get_drvdata(dev);
u8 data[3];
long dummy;
int ret;
switch (type) {
case hwmon_curr:
switch (attr) {
case hwmon_curr_input:
ret = adm1177_read_raw(st, 3, data);
if (ret < 0)
return ret;
dummy = (data[1] << 4) | (data[2] & 0xF);
/*
* convert to milliamperes
* ((105.84mV / 4096) x raw) / senseResistor(ohm)
*/
*val = div_u64((105840000ull * dummy),
4096 * st->r_sense_uohm);
return 0;
case hwmon_curr_max_alarm:
*val = st->alert_threshold_ua;
return 0;
default:
return -EOPNOTSUPP;
}
case hwmon_in:
ret = adm1177_read_raw(st, 3, data);
if (ret < 0)
return ret;
dummy = (data[0] << 4) | (data[2] >> 4);
/*
* convert to millivolts based on resistor devision
* (V_fullscale / 4096) * raw
*/
if (st->vrange_high)
dummy *= 26350;
else
dummy *= 6650;
*val = DIV_ROUND_CLOSEST(dummy, 4096);
return 0;
default:
return -EOPNOTSUPP;
}
}
static int adm1177_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct adm1177_state *st = dev_get_drvdata(dev);
switch (type) {
case hwmon_curr:
switch (attr) {
case hwmon_curr_max_alarm:
adm1177_write_alert_thr(st, val);
return 0;
default:
return -EOPNOTSUPP;
}
default:
return -EOPNOTSUPP;
}
}
static umode_t adm1177_is_visible(const void *data,
enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct adm1177_state *st = data;
switch (type) {
case hwmon_in:
switch (attr) {
case hwmon_in_input:
return 0444;
}
break;
case hwmon_curr:
switch (attr) {
case hwmon_curr_input:
if (st->r_sense_uohm)
return 0444;
return 0;
case hwmon_curr_max_alarm:
if (st->r_sense_uohm)
return 0644;
return 0;
}
break;
default:
break;
}
return 0;
}
static const struct hwmon_channel_info *adm1177_info[] = {
HWMON_CHANNEL_INFO(curr,
HWMON_C_INPUT | HWMON_C_MAX_ALARM),
HWMON_CHANNEL_INFO(in,
HWMON_I_INPUT),
NULL
};
static const struct hwmon_ops adm1177_hwmon_ops = {
.is_visible = adm1177_is_visible,
.read = adm1177_read,
.write = adm1177_write,
};
static const struct hwmon_chip_info adm1177_chip_info = {
.ops = &adm1177_hwmon_ops,
.info = adm1177_info,
};
static void adm1177_remove(void *data)
{
struct adm1177_state *st = data;
regulator_disable(st->reg);
}
static int adm1177_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct adm1177_state *st;
u32 alert_threshold_ua;
int ret;
st = devm_kzalloc(dev, sizeof(*st), GFP_KERNEL);
if (!st)
return -ENOMEM;
st->client = client;
st->reg = devm_regulator_get_optional(&client->dev, "vref");
if (IS_ERR(st->reg)) {
if (PTR_ERR(st->reg) == -EPROBE_DEFER)
return -EPROBE_DEFER;
st->reg = NULL;
} else {
ret = regulator_enable(st->reg);
if (ret)
return ret;
ret = devm_add_action_or_reset(&client->dev, adm1177_remove,
st);
if (ret)
return ret;
}
if (device_property_read_u32(dev, "shunt-resistor-micro-ohms",
&st->r_sense_uohm))
st->r_sense_uohm = 0;
if (device_property_read_u32(dev, "adi,shutdown-threshold-microamp",
&alert_threshold_ua)) {
if (st->r_sense_uohm)
/*
* set maximum default value from datasheet based on
* shunt-resistor
*/
alert_threshold_ua = div_u64(105840000000,
st->r_sense_uohm);
else
alert_threshold_ua = 0;
}
st->vrange_high = device_property_read_bool(dev,
"adi,vrange-high-enable");
if (alert_threshold_ua && st->r_sense_uohm)
adm1177_write_alert_thr(st, alert_threshold_ua);
ret = adm1177_write_cmd(st, ADM1177_CMD_V_CONT |
ADM1177_CMD_I_CONT |
(st->vrange_high ? 0 : ADM1177_CMD_VRANGE));
if (ret)
return ret;
hwmon_dev =
devm_hwmon_device_register_with_info(dev, client->name, st,
&adm1177_chip_info, NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct i2c_device_id adm1177_id[] = {
{"adm1177", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, adm1177_id);
static const struct of_device_id adm1177_dt_ids[] = {
{ .compatible = "adi,adm1177" },
{},
};
MODULE_DEVICE_TABLE(of, adm1177_dt_ids);
static struct i2c_driver adm1177_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "adm1177",
.of_match_table = adm1177_dt_ids,
},
.probe_new = adm1177_probe,
.id_table = adm1177_id,
};
module_i2c_driver(adm1177_driver);
MODULE_AUTHOR("Beniamin Bia <beniamin.bia@analog.com>");
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices ADM1177 ADC driver");
MODULE_LICENSE("GPL v2");
|
