1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Driver for Linear Technology LTC1665/LTC1660, 8 channels DAC |
4 | * |
5 | * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@gmail.com> |
6 | */ |
7 | #include <linux/bitops.h> |
8 | #include <linux/iio/iio.h> |
9 | #include <linux/iio/sysfs.h> |
10 | #include <linux/init.h> |
11 | #include <linux/module.h> |
12 | #include <linux/regulator/consumer.h> |
13 | #include <linux/regmap.h> |
14 | #include <linux/spi/spi.h> |
15 | |
16 | #define LTC1660_REG_WAKE 0x0 |
17 | #define LTC1660_REG_DAC_A 0x1 |
18 | #define LTC1660_REG_DAC_B 0x2 |
19 | #define LTC1660_REG_DAC_C 0x3 |
20 | #define LTC1660_REG_DAC_D 0x4 |
21 | #define LTC1660_REG_DAC_E 0x5 |
22 | #define LTC1660_REG_DAC_F 0x6 |
23 | #define LTC1660_REG_DAC_G 0x7 |
24 | #define LTC1660_REG_DAC_H 0x8 |
25 | #define LTC1660_REG_SLEEP 0xe |
26 | |
27 | #define LTC1660_NUM_CHANNELS 8 |
28 | |
29 | static const struct regmap_config ltc1660_regmap_config = { |
30 | .reg_bits = 4, |
31 | .val_bits = 12, |
32 | }; |
33 | |
34 | enum ltc1660_supported_device_ids { |
35 | ID_LTC1660, |
36 | ID_LTC1665, |
37 | }; |
38 | |
39 | struct ltc1660_priv { |
40 | struct spi_device *spi; |
41 | struct regmap *regmap; |
42 | struct regulator *vref_reg; |
43 | unsigned int value[LTC1660_NUM_CHANNELS]; |
44 | unsigned int vref_mv; |
45 | }; |
46 | |
47 | static int ltc1660_read_raw(struct iio_dev *indio_dev, |
48 | struct iio_chan_spec const *chan, |
49 | int *val, |
50 | int *val2, |
51 | long mask) |
52 | { |
53 | struct ltc1660_priv *priv = iio_priv(indio_dev); |
54 | |
55 | switch (mask) { |
56 | case IIO_CHAN_INFO_RAW: |
57 | *val = priv->value[chan->channel]; |
58 | return IIO_VAL_INT; |
59 | case IIO_CHAN_INFO_SCALE: |
60 | *val = regulator_get_voltage(regulator: priv->vref_reg); |
61 | if (*val < 0) { |
62 | dev_err(&priv->spi->dev, "failed to read vref regulator: %d\n" , |
63 | *val); |
64 | return *val; |
65 | } |
66 | |
67 | /* Convert to mV */ |
68 | *val /= 1000; |
69 | *val2 = chan->scan_type.realbits; |
70 | return IIO_VAL_FRACTIONAL_LOG2; |
71 | default: |
72 | return -EINVAL; |
73 | } |
74 | } |
75 | |
76 | static int ltc1660_write_raw(struct iio_dev *indio_dev, |
77 | struct iio_chan_spec const *chan, |
78 | int val, |
79 | int val2, |
80 | long mask) |
81 | { |
82 | struct ltc1660_priv *priv = iio_priv(indio_dev); |
83 | int ret; |
84 | |
85 | switch (mask) { |
86 | case IIO_CHAN_INFO_RAW: |
87 | if (val2 != 0) |
88 | return -EINVAL; |
89 | |
90 | if (val < 0 || val > GENMASK(chan->scan_type.realbits - 1, 0)) |
91 | return -EINVAL; |
92 | |
93 | ret = regmap_write(map: priv->regmap, reg: chan->channel, |
94 | val: (val << chan->scan_type.shift)); |
95 | if (!ret) |
96 | priv->value[chan->channel] = val; |
97 | |
98 | return ret; |
99 | default: |
100 | return -EINVAL; |
101 | } |
102 | } |
103 | |
104 | #define LTC1660_CHAN(chan, bits) { \ |
105 | .type = IIO_VOLTAGE, \ |
106 | .indexed = 1, \ |
107 | .output = 1, \ |
108 | .channel = chan, \ |
109 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
110 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
111 | .scan_type = { \ |
112 | .sign = 'u', \ |
113 | .realbits = (bits), \ |
114 | .storagebits = 16, \ |
115 | .shift = 12 - (bits), \ |
116 | }, \ |
117 | } |
118 | |
119 | #define LTC1660_OCTAL_CHANNELS(bits) { \ |
120 | LTC1660_CHAN(LTC1660_REG_DAC_A, bits), \ |
121 | LTC1660_CHAN(LTC1660_REG_DAC_B, bits), \ |
122 | LTC1660_CHAN(LTC1660_REG_DAC_C, bits), \ |
123 | LTC1660_CHAN(LTC1660_REG_DAC_D, bits), \ |
124 | LTC1660_CHAN(LTC1660_REG_DAC_E, bits), \ |
125 | LTC1660_CHAN(LTC1660_REG_DAC_F, bits), \ |
126 | LTC1660_CHAN(LTC1660_REG_DAC_G, bits), \ |
127 | LTC1660_CHAN(LTC1660_REG_DAC_H, bits), \ |
128 | } |
129 | |
130 | static const struct iio_chan_spec ltc1660_channels[][LTC1660_NUM_CHANNELS] = { |
131 | [ID_LTC1660] = LTC1660_OCTAL_CHANNELS(10), |
132 | [ID_LTC1665] = LTC1660_OCTAL_CHANNELS(8), |
133 | }; |
134 | |
135 | static const struct iio_info ltc1660_info = { |
136 | .read_raw = <c1660_read_raw, |
137 | .write_raw = <c1660_write_raw, |
138 | }; |
139 | |
140 | static int ltc1660_suspend(struct device *dev) |
141 | { |
142 | struct ltc1660_priv *priv = iio_priv(indio_dev: spi_get_drvdata( |
143 | spi: to_spi_device(dev))); |
144 | return regmap_write(map: priv->regmap, LTC1660_REG_SLEEP, val: 0x00); |
145 | } |
146 | |
147 | static int ltc1660_resume(struct device *dev) |
148 | { |
149 | struct ltc1660_priv *priv = iio_priv(indio_dev: spi_get_drvdata( |
150 | spi: to_spi_device(dev))); |
151 | return regmap_write(map: priv->regmap, LTC1660_REG_WAKE, val: 0x00); |
152 | } |
153 | static DEFINE_SIMPLE_DEV_PM_OPS(ltc1660_pm_ops, ltc1660_suspend, |
154 | ltc1660_resume); |
155 | |
156 | static int ltc1660_probe(struct spi_device *spi) |
157 | { |
158 | struct iio_dev *indio_dev; |
159 | struct ltc1660_priv *priv; |
160 | const struct spi_device_id *id = spi_get_device_id(sdev: spi); |
161 | int ret; |
162 | |
163 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*priv)); |
164 | if (indio_dev == NULL) |
165 | return -ENOMEM; |
166 | |
167 | priv = iio_priv(indio_dev); |
168 | priv->regmap = devm_regmap_init_spi(spi, <c1660_regmap_config); |
169 | if (IS_ERR(ptr: priv->regmap)) { |
170 | dev_err(&spi->dev, "failed to register spi regmap %ld\n" , |
171 | PTR_ERR(priv->regmap)); |
172 | return PTR_ERR(ptr: priv->regmap); |
173 | } |
174 | |
175 | priv->vref_reg = devm_regulator_get(dev: &spi->dev, id: "vref" ); |
176 | if (IS_ERR(ptr: priv->vref_reg)) |
177 | return dev_err_probe(dev: &spi->dev, err: PTR_ERR(ptr: priv->vref_reg), |
178 | fmt: "vref regulator not specified\n" ); |
179 | |
180 | ret = regulator_enable(regulator: priv->vref_reg); |
181 | if (ret) { |
182 | dev_err(&spi->dev, "failed to enable vref regulator: %d\n" , |
183 | ret); |
184 | return ret; |
185 | } |
186 | |
187 | priv->spi = spi; |
188 | spi_set_drvdata(spi, data: indio_dev); |
189 | indio_dev->info = <c1660_info; |
190 | indio_dev->modes = INDIO_DIRECT_MODE; |
191 | indio_dev->channels = ltc1660_channels[id->driver_data]; |
192 | indio_dev->num_channels = LTC1660_NUM_CHANNELS; |
193 | indio_dev->name = id->name; |
194 | |
195 | ret = iio_device_register(indio_dev); |
196 | if (ret) { |
197 | dev_err(&spi->dev, "failed to register iio device: %d\n" , |
198 | ret); |
199 | goto error_disable_reg; |
200 | } |
201 | |
202 | return 0; |
203 | |
204 | error_disable_reg: |
205 | regulator_disable(regulator: priv->vref_reg); |
206 | |
207 | return ret; |
208 | } |
209 | |
210 | static void ltc1660_remove(struct spi_device *spi) |
211 | { |
212 | struct iio_dev *indio_dev = spi_get_drvdata(spi); |
213 | struct ltc1660_priv *priv = iio_priv(indio_dev); |
214 | |
215 | iio_device_unregister(indio_dev); |
216 | regulator_disable(regulator: priv->vref_reg); |
217 | } |
218 | |
219 | static const struct of_device_id ltc1660_dt_ids[] = { |
220 | { .compatible = "lltc,ltc1660" , .data = (void *)ID_LTC1660 }, |
221 | { .compatible = "lltc,ltc1665" , .data = (void *)ID_LTC1665 }, |
222 | { /* sentinel */ } |
223 | }; |
224 | MODULE_DEVICE_TABLE(of, ltc1660_dt_ids); |
225 | |
226 | static const struct spi_device_id ltc1660_id[] = { |
227 | {"ltc1660" , ID_LTC1660}, |
228 | {"ltc1665" , ID_LTC1665}, |
229 | { /* sentinel */ } |
230 | }; |
231 | MODULE_DEVICE_TABLE(spi, ltc1660_id); |
232 | |
233 | static struct spi_driver ltc1660_driver = { |
234 | .driver = { |
235 | .name = "ltc1660" , |
236 | .of_match_table = ltc1660_dt_ids, |
237 | .pm = pm_sleep_ptr(<c1660_pm_ops), |
238 | }, |
239 | .probe = ltc1660_probe, |
240 | .remove = ltc1660_remove, |
241 | .id_table = ltc1660_id, |
242 | }; |
243 | module_spi_driver(ltc1660_driver); |
244 | |
245 | MODULE_AUTHOR("Marcus Folkesson <marcus.folkesson@gmail.com>" ); |
246 | MODULE_DESCRIPTION("Linear Technology LTC1660/LTC1665 DAC" ); |
247 | MODULE_LICENSE("GPL v2" ); |
248 | |