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
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* BD79703 ROHM Digital to Analog converter
*
* Copyright (c) 2024, ROHM Semiconductor.
*/
#include <linux/bits.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#define BD79703_MAX_REGISTER 0xf
#define BD79703_DAC_BITS 8
#define BD79703_REG_OUT_ALL GENMASK(2, 0)
/*
* The BD79703 uses 12-bit SPI commands. First four bits (high bits) define
* channel(s) which are operated on, and also the mode. The mode can be to set
* a DAC word only, or set DAC word and output. The data-sheet is not very
* specific on how a previously set DAC word can be 'taken in to use'. Thus
* this driver only uses the 'set DAC and output it' -mode.
*
* The BD79703 latches last 12-bits when the chip-select is toggled. Thus we
* can use 16-bit transfers which should be widely supported. To simplify this
* further, we treat the last 8 bits as a value, and first 8 bits as an
* address. This allows us to separate channels/mode by address and treat the
* 8-bit register value as DAC word. The highest 4 bits of address will be
* discarded when the transfer is latched.
*/
static const struct regmap_config bd79703_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = BD79703_MAX_REGISTER,
.cache_type = REGCACHE_RBTREE,
};
/* Dynamic driver private data */
struct bd79703_data {
struct regmap *regmap;
int vfs;
};
/* Static, IC type specific data for different variants */
struct bd7970x_chip_data {
const char *name;
const struct iio_chan_spec *channels;
int num_channels;
bool has_vfs;
};
static int bd79703_read_raw(struct iio_dev *idev,
struct iio_chan_spec const *chan, int *val,
int *val2, long mask)
{
struct bd79703_data *data = iio_priv(idev);
if (mask != IIO_CHAN_INFO_SCALE)
return -EINVAL;
*val = data->vfs / 1000;
*val2 = BD79703_DAC_BITS;
return IIO_VAL_FRACTIONAL_LOG2;
}
static int bd79703_write_raw(struct iio_dev *idev,
struct iio_chan_spec const *chan, int val,
int val2, long mask)
{
struct bd79703_data *data = iio_priv(idev);
if (val < 0 || val >= 1 << BD79703_DAC_BITS)
return -EINVAL;
return regmap_write(data->regmap, chan->address, val);
};
static const struct iio_info bd79703_info = {
.read_raw = bd79703_read_raw,
.write_raw = bd79703_write_raw,
};
#define BD79703_CHAN_ADDR(_chan, _addr) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (_chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.address = (_addr), \
}
#define BD79703_CHAN(_chan) BD79703_CHAN_ADDR((_chan), (_chan) + 1)
static const struct iio_chan_spec bd79700_channels[] = {
BD79703_CHAN(0),
BD79703_CHAN(1),
};
static const struct iio_chan_spec bd79701_channels[] = {
BD79703_CHAN(0),
BD79703_CHAN(1),
BD79703_CHAN(2),
};
/*
* The BD79702 has 4 channels. They aren't mapped to BD79703 channels 0, 1, 2
* and 3, but to the channels 0, 1, 4, 5. So the addressing used with SPI
* accesses is 1, 2, 5 and 6 for them. Thus, they're not constant offset to
* the channel number as with other IC variants.
*/
static const struct iio_chan_spec bd79702_channels[] = {
BD79703_CHAN_ADDR(0, 1),
BD79703_CHAN_ADDR(1, 2),
BD79703_CHAN_ADDR(2, 5),
BD79703_CHAN_ADDR(3, 6),
};
static const struct iio_chan_spec bd79703_channels[] = {
BD79703_CHAN(0),
BD79703_CHAN(1),
BD79703_CHAN(2),
BD79703_CHAN(3),
BD79703_CHAN(4),
BD79703_CHAN(5),
};
static const struct bd7970x_chip_data bd79700_chip_data = {
.name = "bd79700",
.channels = bd79700_channels,
.num_channels = ARRAY_SIZE(bd79700_channels),
.has_vfs = false,
};
static const struct bd7970x_chip_data bd79701_chip_data = {
.name = "bd79701",
.channels = bd79701_channels,
.num_channels = ARRAY_SIZE(bd79701_channels),
.has_vfs = false,
};
static const struct bd7970x_chip_data bd79702_chip_data = {
.name = "bd79702",
.channels = bd79702_channels,
.num_channels = ARRAY_SIZE(bd79702_channels),
.has_vfs = true,
};
static const struct bd7970x_chip_data bd79703_chip_data = {
.name = "bd79703",
.channels = bd79703_channels,
.num_channels = ARRAY_SIZE(bd79703_channels),
.has_vfs = true,
};
static int bd79703_probe(struct spi_device *spi)
{
const struct bd7970x_chip_data *cd;
struct device *dev = &spi->dev;
struct bd79703_data *data;
struct iio_dev *idev;
int ret;
cd = spi_get_device_match_data(spi);
if (!cd)
return -ENODEV;
idev = devm_iio_device_alloc(dev, sizeof(*data));
if (!idev)
return -ENOMEM;
data = iio_priv(idev);
data->regmap = devm_regmap_init_spi(spi, &bd79703_regmap_config);
if (IS_ERR(data->regmap))
return dev_err_probe(dev, PTR_ERR(data->regmap),
"Failed to initialize Regmap\n");
/*
* BD79703 has a separate VFS pin, whereas the BD79700 and BD79701 use
* VCC for their full-scale output voltage.
*/
if (cd->has_vfs) {
ret = devm_regulator_get_enable(dev, "vcc");
if (ret)
return dev_err_probe(dev, ret, "Failed to enable VCC\n");
ret = devm_regulator_get_enable_read_voltage(dev, "vfs");
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to get Vfs\n");
} else {
ret = devm_regulator_get_enable_read_voltage(dev, "vcc");
if (ret < 0)
return dev_err_probe(dev, ret, "Failed to get VCC\n");
}
data->vfs = ret;
idev->channels = cd->channels;
idev->num_channels = cd->num_channels;
idev->modes = INDIO_DIRECT_MODE;
idev->info = &bd79703_info;
idev->name = cd->name;
/* Initialize all to output zero */
ret = regmap_write(data->regmap, BD79703_REG_OUT_ALL, 0);
if (ret)
return ret;
return devm_iio_device_register(dev, idev);
}
static const struct spi_device_id bd79703_id[] = {
{ "bd79700", (kernel_ulong_t)&bd79700_chip_data },
{ "bd79701", (kernel_ulong_t)&bd79701_chip_data },
{ "bd79702", (kernel_ulong_t)&bd79702_chip_data },
{ "bd79703", (kernel_ulong_t)&bd79703_chip_data },
{ }
};
MODULE_DEVICE_TABLE(spi, bd79703_id);
static const struct of_device_id bd79703_of_match[] = {
{ .compatible = "rohm,bd79700", .data = &bd79700_chip_data },
{ .compatible = "rohm,bd79701", .data = &bd79701_chip_data },
{ .compatible = "rohm,bd79702", .data = &bd79702_chip_data },
{ .compatible = "rohm,bd79703", .data = &bd79703_chip_data },
{ }
};
MODULE_DEVICE_TABLE(of, bd79703_of_match);
static struct spi_driver bd79703_driver = {
.driver = {
.name = "bd79703",
.of_match_table = bd79703_of_match,
},
.probe = bd79703_probe,
.id_table = bd79703_id,
};
module_spi_driver(bd79703_driver);
MODULE_AUTHOR("Matti Vaittinen <mazziesaccount@gmail.com>");
MODULE_DESCRIPTION("ROHM BD79703 DAC driver");
MODULE_LICENSE("GPL");
|
