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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* ltc2497-core.c - Common code for Analog Devices/Linear Technology
* LTC2496 and LTC2497 ADCs
*
* Copyright (C) 2017 Analog Devices Inc.
*/
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/driver.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/regulator/consumer.h>
#include "ltc2497.h"
#define LTC2497_SGL BIT(4)
#define LTC2497_DIFF 0
#define LTC2497_SIGN BIT(3)
static int ltc2497core_wait_conv(struct ltc2497core_driverdata *ddata)
{
s64 time_elapsed;
time_elapsed = ktime_ms_delta(ktime_get(), ddata->time_prev);
if (time_elapsed < LTC2497_CONVERSION_TIME_MS) {
/* delay if conversion time not passed
* since last read or write
*/
if (msleep_interruptible(
LTC2497_CONVERSION_TIME_MS - time_elapsed))
return -ERESTARTSYS;
return 0;
}
if (time_elapsed - LTC2497_CONVERSION_TIME_MS <= 0) {
/* We're in automatic mode -
* so the last reading is still not outdated
*/
return 0;
}
return 1;
}
static int ltc2497core_read(struct ltc2497core_driverdata *ddata, u8 address, int *val)
{
int ret;
ret = ltc2497core_wait_conv(ddata);
if (ret < 0)
return ret;
if (ret || ddata->addr_prev != address) {
ret = ddata->result_and_measure(ddata, address, NULL);
if (ret < 0)
return ret;
ddata->addr_prev = address;
if (msleep_interruptible(LTC2497_CONVERSION_TIME_MS))
return -ERESTARTSYS;
}
ret = ddata->result_and_measure(ddata, address, val);
if (ret < 0)
return ret;
ddata->time_prev = ktime_get();
return ret;
}
static int ltc2497core_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&ddata->lock);
ret = ltc2497core_read(ddata, chan->address, val);
mutex_unlock(&ddata->lock);
if (ret < 0)
return ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = regulator_get_voltage(ddata->ref);
if (ret < 0)
return ret;
*val = ret / 1000;
*val2 = ddata->chip_info->resolution + 1;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
}
}
#define LTC2497_CHAN(_chan, _addr, _ds_name) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (_chan), \
.address = (_addr | (_chan / 2) | ((_chan & 1) ? LTC2497_SIGN : 0)), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.datasheet_name = (_ds_name), \
}
#define LTC2497_CHAN_DIFF(_chan, _addr) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 1 : 0), \
.channel2 = (_chan) * 2 + ((_addr) & LTC2497_SIGN ? 0 : 1),\
.address = (_addr | _chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.differential = 1, \
}
static const struct iio_chan_spec ltc2497core_channel[] = {
LTC2497_CHAN(0, LTC2497_SGL, "CH0"),
LTC2497_CHAN(1, LTC2497_SGL, "CH1"),
LTC2497_CHAN(2, LTC2497_SGL, "CH2"),
LTC2497_CHAN(3, LTC2497_SGL, "CH3"),
LTC2497_CHAN(4, LTC2497_SGL, "CH4"),
LTC2497_CHAN(5, LTC2497_SGL, "CH5"),
LTC2497_CHAN(6, LTC2497_SGL, "CH6"),
LTC2497_CHAN(7, LTC2497_SGL, "CH7"),
LTC2497_CHAN(8, LTC2497_SGL, "CH8"),
LTC2497_CHAN(9, LTC2497_SGL, "CH9"),
LTC2497_CHAN(10, LTC2497_SGL, "CH10"),
LTC2497_CHAN(11, LTC2497_SGL, "CH11"),
LTC2497_CHAN(12, LTC2497_SGL, "CH12"),
LTC2497_CHAN(13, LTC2497_SGL, "CH13"),
LTC2497_CHAN(14, LTC2497_SGL, "CH14"),
LTC2497_CHAN(15, LTC2497_SGL, "CH15"),
LTC2497_CHAN_DIFF(0, LTC2497_DIFF),
LTC2497_CHAN_DIFF(1, LTC2497_DIFF),
LTC2497_CHAN_DIFF(2, LTC2497_DIFF),
LTC2497_CHAN_DIFF(3, LTC2497_DIFF),
LTC2497_CHAN_DIFF(4, LTC2497_DIFF),
LTC2497_CHAN_DIFF(5, LTC2497_DIFF),
LTC2497_CHAN_DIFF(6, LTC2497_DIFF),
LTC2497_CHAN_DIFF(7, LTC2497_DIFF),
LTC2497_CHAN_DIFF(0, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(1, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(2, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(3, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(4, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(5, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(6, LTC2497_DIFF | LTC2497_SIGN),
LTC2497_CHAN_DIFF(7, LTC2497_DIFF | LTC2497_SIGN),
};
static const struct iio_info ltc2497core_info = {
.read_raw = ltc2497core_read_raw,
};
int ltc2497core_probe(struct device *dev, struct iio_dev *indio_dev)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
struct iio_map *plat_data = dev_get_platdata(dev);
int ret;
/*
* Keep using dev_name() for the iio_dev's name on some of the parts,
* since updating it would result in a ABI breakage.
*/
if (ddata->chip_info->name)
indio_dev->name = ddata->chip_info->name;
else
indio_dev->name = dev_name(dev);
indio_dev->info = <c2497core_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ltc2497core_channel;
indio_dev->num_channels = ARRAY_SIZE(ltc2497core_channel);
ret = ddata->result_and_measure(ddata, LTC2497_CONFIG_DEFAULT, NULL);
if (ret < 0)
return ret;
ddata->ref = devm_regulator_get(dev, "vref");
if (IS_ERR(ddata->ref))
return dev_err_probe(dev, PTR_ERR(ddata->ref),
"Failed to get vref regulator\n");
ret = regulator_enable(ddata->ref);
if (ret < 0) {
dev_err(dev, "Failed to enable vref regulator: %pe\n",
ERR_PTR(ret));
return ret;
}
ret = iio_map_array_register(indio_dev, plat_data);
if (ret) {
dev_err(&indio_dev->dev, "iio map err: %d\n", ret);
goto err_regulator_disable;
}
ddata->addr_prev = LTC2497_CONFIG_DEFAULT;
ddata->time_prev = ktime_get();
mutex_init(&ddata->lock);
ret = iio_device_register(indio_dev);
if (ret < 0)
goto err_array_unregister;
return 0;
err_array_unregister:
iio_map_array_unregister(indio_dev);
err_regulator_disable:
regulator_disable(ddata->ref);
return ret;
}
EXPORT_SYMBOL_NS(ltc2497core_probe, LTC2497);
void ltc2497core_remove(struct iio_dev *indio_dev)
{
struct ltc2497core_driverdata *ddata = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_map_array_unregister(indio_dev);
regulator_disable(ddata->ref);
}
EXPORT_SYMBOL_NS(ltc2497core_remove, LTC2497);
MODULE_DESCRIPTION("common code for LTC2496/LTC2497 drivers");
MODULE_LICENSE("GPL v2");
|
