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 | |
16 | struct tpl0102_cfg { |
17 | int wipers; |
18 | int avail[3]; |
19 | int kohms; |
20 | }; |
21 | |
22 | enum tpl0102_type { |
23 | CAT5140_503, |
24 | CAT5140_104, |
25 | TPL0102_104, |
26 | TPL0401_103, |
27 | }; |
28 | |
29 | static 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 | |
38 | struct tpl0102_data { |
39 | struct regmap *regmap; |
40 | const struct tpl0102_cfg *cfg; |
41 | }; |
42 | |
43 | static 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 | |
58 | static const struct iio_chan_spec tpl0102_channels[] = { |
59 | TPL0102_CHANNEL(0), |
60 | TPL0102_CHANNEL(1), |
61 | }; |
62 | |
63 | static 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 | |
84 | static 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 | |
102 | static 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 | |
117 | static 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 | |
123 | static 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 | |
151 | static 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 | }; |
158 | MODULE_DEVICE_TABLE(i2c, tpl0102_id); |
159 | |
160 | static struct i2c_driver tpl0102_driver = { |
161 | .driver = { |
162 | .name = "tpl0102" , |
163 | }, |
164 | .probe = tpl0102_probe, |
165 | .id_table = tpl0102_id, |
166 | }; |
167 | |
168 | module_i2c_driver(tpl0102_driver); |
169 | |
170 | MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>" ); |
171 | MODULE_DESCRIPTION("TPL0102 digital potentiometer" ); |
172 | MODULE_LICENSE("GPL" ); |
173 | |