1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * tpl0102.c - Support for Texas Instruments digital potentiometers
4 *
5 * Copyright (C) 2016, 2018
6 * Author: Matt Ranostay <matt.ranostay@konsulko.com>
7 *
8 * TODO: enable/disable hi-z output control
9 */
10
11#include <linux/module.h>
12#include <linux/i2c.h>
13#include <linux/regmap.h>
14#include <linux/iio/iio.h>
15
16struct tpl0102_cfg {
17 int wipers;
18 int avail[3];
19 int kohms;
20};
21
22enum tpl0102_type {
23 CAT5140_503,
24 CAT5140_104,
25 TPL0102_104,
26 TPL0401_103,
27};
28
29static const struct tpl0102_cfg tpl0102_cfg[] = {
30 /* on-semiconductor parts */
31 [CAT5140_503] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 50, },
32 [CAT5140_104] = { .wipers = 1, .avail = { 0, 1, 255 }, .kohms = 100, },
33 /* ti parts */
34 [TPL0102_104] = { .wipers = 2, .avail = { 0, 1, 255 }, .kohms = 100 },
35 [TPL0401_103] = { .wipers = 1, .avail = { 0, 1, 127 }, .kohms = 10, },
36};
37
38struct tpl0102_data {
39 struct regmap *regmap;
40 const struct tpl0102_cfg *cfg;
41};
42
43static const struct regmap_config tpl0102_regmap_config = {
44 .reg_bits = 8,
45 .val_bits = 8,
46};
47
48#define TPL0102_CHANNEL(ch) { \
49 .type = IIO_RESISTANCE, \
50 .indexed = 1, \
51 .output = 1, \
52 .channel = (ch), \
53 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
54 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
55 .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW), \
56}
57
58static const struct iio_chan_spec tpl0102_channels[] = {
59 TPL0102_CHANNEL(0),
60 TPL0102_CHANNEL(1),
61};
62
63static int tpl0102_read_raw(struct iio_dev *indio_dev,
64 struct iio_chan_spec const *chan,
65 int *val, int *val2, long mask)
66{
67 struct tpl0102_data *data = iio_priv(indio_dev);
68
69 switch (mask) {
70 case IIO_CHAN_INFO_RAW: {
71 int ret = regmap_read(map: data->regmap, reg: chan->channel, val);
72
73 return ret ? ret : IIO_VAL_INT;
74 }
75 case IIO_CHAN_INFO_SCALE:
76 *val = 1000 * data->cfg->kohms;
77 *val2 = data->cfg->avail[2] + 1;
78 return IIO_VAL_FRACTIONAL;
79 }
80
81 return -EINVAL;
82}
83
84static int tpl0102_read_avail(struct iio_dev *indio_dev,
85 struct iio_chan_spec const *chan,
86 const int **vals, int *type, int *length,
87 long mask)
88{
89 struct tpl0102_data *data = iio_priv(indio_dev);
90
91 switch (mask) {
92 case IIO_CHAN_INFO_RAW:
93 *length = ARRAY_SIZE(data->cfg->avail);
94 *vals = data->cfg->avail;
95 *type = IIO_VAL_INT;
96 return IIO_AVAIL_RANGE;
97 }
98
99 return -EINVAL;
100}
101
102static int tpl0102_write_raw(struct iio_dev *indio_dev,
103 struct iio_chan_spec const *chan,
104 int val, int val2, long mask)
105{
106 struct tpl0102_data *data = iio_priv(indio_dev);
107
108 if (mask != IIO_CHAN_INFO_RAW)
109 return -EINVAL;
110
111 if (val > data->cfg->avail[2] || val < 0)
112 return -EINVAL;
113
114 return regmap_write(map: data->regmap, reg: chan->channel, val);
115}
116
117static const struct iio_info tpl0102_info = {
118 .read_raw = tpl0102_read_raw,
119 .read_avail = tpl0102_read_avail,
120 .write_raw = tpl0102_write_raw,
121};
122
123static int tpl0102_probe(struct i2c_client *client)
124{
125 const struct i2c_device_id *id = i2c_client_get_device_id(client);
126 struct device *dev = &client->dev;
127 struct tpl0102_data *data;
128 struct iio_dev *indio_dev;
129
130 indio_dev = devm_iio_device_alloc(parent: dev, sizeof_priv: sizeof(*data));
131 if (!indio_dev)
132 return -ENOMEM;
133 data = iio_priv(indio_dev);
134 i2c_set_clientdata(client, data: indio_dev);
135
136 data->cfg = &tpl0102_cfg[id->driver_data];
137 data->regmap = devm_regmap_init_i2c(client, &tpl0102_regmap_config);
138 if (IS_ERR(ptr: data->regmap)) {
139 dev_err(dev, "regmap initialization failed\n");
140 return PTR_ERR(ptr: data->regmap);
141 }
142
143 indio_dev->info = &tpl0102_info;
144 indio_dev->channels = tpl0102_channels;
145 indio_dev->num_channels = data->cfg->wipers;
146 indio_dev->name = client->name;
147
148 return devm_iio_device_register(dev, indio_dev);
149}
150
151static const struct i2c_device_id tpl0102_id[] = {
152 { "cat5140-503", CAT5140_503 },
153 { "cat5140-104", CAT5140_104 },
154 { "tpl0102-104", TPL0102_104 },
155 { "tpl0401-103", TPL0401_103 },
156 {}
157};
158MODULE_DEVICE_TABLE(i2c, tpl0102_id);
159
160static struct i2c_driver tpl0102_driver = {
161 .driver = {
162 .name = "tpl0102",
163 },
164 .probe = tpl0102_probe,
165 .id_table = tpl0102_id,
166};
167
168module_i2c_driver(tpl0102_driver);
169
170MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
171MODULE_DESCRIPTION("TPL0102 digital potentiometer");
172MODULE_LICENSE("GPL");
173

source code of linux/drivers/iio/potentiometer/tpl0102.c