1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Maxim MAX5522 |
4 | * Dual, Ultra-Low-Power 10-Bit, Voltage-Output DACs |
5 | * |
6 | * Copyright 2022 Timesys Corp. |
7 | */ |
8 | |
9 | #include <linux/device.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> |
12 | #include <linux/mod_devicetable.h> |
13 | #include <linux/regmap.h> |
14 | #include <linux/regulator/consumer.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/spi/spi.h> |
17 | |
18 | #include <linux/iio/iio.h> |
19 | |
20 | #define MAX5522_MAX_ADDR 15 |
21 | #define MAX5522_CTRL_NONE 0 |
22 | #define MAX5522_CTRL_LOAD_IN_A 9 |
23 | #define MAX5522_CTRL_LOAD_IN_B 10 |
24 | |
25 | #define MAX5522_REG_DATA(x) ((x) + MAX5522_CTRL_LOAD_IN_A) |
26 | |
27 | struct max5522_chip_info { |
28 | const char *name; |
29 | const struct iio_chan_spec *channels; |
30 | unsigned int num_channels; |
31 | }; |
32 | |
33 | struct max5522_state { |
34 | struct regmap *regmap; |
35 | const struct max5522_chip_info *chip_info; |
36 | unsigned short dac_cache[2]; |
37 | struct regulator *vrefin_reg; |
38 | }; |
39 | |
40 | #define MAX5522_CHANNEL(chan) { \ |
41 | .type = IIO_VOLTAGE, \ |
42 | .indexed = 1, \ |
43 | .output = 1, \ |
44 | .channel = chan, \ |
45 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \ |
46 | BIT(IIO_CHAN_INFO_SCALE), \ |
47 | .scan_type = { \ |
48 | .sign = 'u', \ |
49 | .realbits = 10, \ |
50 | .storagebits = 16, \ |
51 | .shift = 2, \ |
52 | } \ |
53 | } |
54 | |
55 | static const struct iio_chan_spec max5522_channels[] = { |
56 | MAX5522_CHANNEL(0), |
57 | MAX5522_CHANNEL(1), |
58 | }; |
59 | |
60 | enum max5522_type { |
61 | ID_MAX5522, |
62 | }; |
63 | |
64 | static const struct max5522_chip_info max5522_chip_info_tbl[] = { |
65 | [ID_MAX5522] = { |
66 | .name = "max5522" , |
67 | .channels = max5522_channels, |
68 | .num_channels = 2, |
69 | }, |
70 | }; |
71 | |
72 | static inline int max5522_info_to_reg(struct iio_chan_spec const *chan) |
73 | { |
74 | return MAX5522_REG_DATA(chan->channel); |
75 | } |
76 | |
77 | static int max5522_read_raw(struct iio_dev *indio_dev, |
78 | struct iio_chan_spec const *chan, |
79 | int *val, int *val2, long info) |
80 | { |
81 | struct max5522_state *state = iio_priv(indio_dev); |
82 | int ret; |
83 | |
84 | switch (info) { |
85 | case IIO_CHAN_INFO_RAW: |
86 | *val = state->dac_cache[chan->channel]; |
87 | return IIO_VAL_INT; |
88 | case IIO_CHAN_INFO_SCALE: |
89 | ret = regulator_get_voltage(regulator: state->vrefin_reg); |
90 | if (ret < 0) |
91 | return -EINVAL; |
92 | *val = ret / 1000; |
93 | *val2 = 10; |
94 | return IIO_VAL_FRACTIONAL_LOG2; |
95 | default: |
96 | return -EINVAL; |
97 | } |
98 | |
99 | return -EINVAL; |
100 | } |
101 | |
102 | static int max5522_write_raw(struct iio_dev *indio_dev, |
103 | struct iio_chan_spec const *chan, |
104 | int val, int val2, long info) |
105 | { |
106 | struct max5522_state *state = iio_priv(indio_dev); |
107 | int rval; |
108 | |
109 | if (val > 1023 || val < 0) |
110 | return -EINVAL; |
111 | |
112 | rval = regmap_write(map: state->regmap, reg: max5522_info_to_reg(chan), |
113 | val: val << chan->scan_type.shift); |
114 | if (rval < 0) |
115 | return rval; |
116 | |
117 | state->dac_cache[chan->channel] = val; |
118 | |
119 | return 0; |
120 | } |
121 | |
122 | static const struct iio_info max5522_info = { |
123 | .read_raw = max5522_read_raw, |
124 | .write_raw = max5522_write_raw, |
125 | }; |
126 | |
127 | static const struct regmap_config max5522_regmap_config = { |
128 | .reg_bits = 4, |
129 | .val_bits = 12, |
130 | .max_register = MAX5522_MAX_ADDR, |
131 | }; |
132 | |
133 | static int max5522_spi_probe(struct spi_device *spi) |
134 | { |
135 | const struct spi_device_id *id = spi_get_device_id(sdev: spi); |
136 | struct iio_dev *indio_dev; |
137 | struct max5522_state *state; |
138 | int ret; |
139 | |
140 | indio_dev = devm_iio_device_alloc(parent: &spi->dev, sizeof_priv: sizeof(*state)); |
141 | if (indio_dev == NULL) { |
142 | dev_err(&spi->dev, "failed to allocate iio device\n" ); |
143 | return -ENOMEM; |
144 | } |
145 | |
146 | state = iio_priv(indio_dev); |
147 | state->chip_info = device_get_match_data(dev: &spi->dev); |
148 | if (!state->chip_info) { |
149 | state->chip_info = |
150 | (struct max5522_chip_info *)(id->driver_data); |
151 | if (!state->chip_info) |
152 | return -EINVAL; |
153 | } |
154 | |
155 | state->vrefin_reg = devm_regulator_get(dev: &spi->dev, id: "vrefin" ); |
156 | if (IS_ERR(ptr: state->vrefin_reg)) |
157 | return dev_err_probe(dev: &spi->dev, err: PTR_ERR(ptr: state->vrefin_reg), |
158 | fmt: "Vrefin regulator not specified\n" ); |
159 | |
160 | ret = regulator_enable(regulator: state->vrefin_reg); |
161 | if (ret) { |
162 | return dev_err_probe(dev: &spi->dev, err: ret, |
163 | fmt: "Failed to enable vref regulators\n" ); |
164 | } |
165 | |
166 | state->regmap = devm_regmap_init_spi(spi, &max5522_regmap_config); |
167 | |
168 | if (IS_ERR(ptr: state->regmap)) |
169 | return PTR_ERR(ptr: state->regmap); |
170 | |
171 | indio_dev->info = &max5522_info; |
172 | indio_dev->modes = INDIO_DIRECT_MODE; |
173 | indio_dev->channels = max5522_channels; |
174 | indio_dev->num_channels = ARRAY_SIZE(max5522_channels); |
175 | indio_dev->name = max5522_chip_info_tbl[ID_MAX5522].name; |
176 | |
177 | return devm_iio_device_register(&spi->dev, indio_dev); |
178 | } |
179 | |
180 | static const struct spi_device_id max5522_ids[] = { |
181 | { "max5522" , (kernel_ulong_t)&max5522_chip_info_tbl[ID_MAX5522] }, |
182 | {} |
183 | }; |
184 | MODULE_DEVICE_TABLE(spi, max5522_ids); |
185 | |
186 | static const struct of_device_id max5522_of_match[] = { |
187 | { |
188 | .compatible = "maxim,max5522" , |
189 | .data = &max5522_chip_info_tbl[ID_MAX5522], |
190 | }, |
191 | {} |
192 | }; |
193 | MODULE_DEVICE_TABLE(of, max5522_of_match); |
194 | |
195 | static struct spi_driver max5522_spi_driver = { |
196 | .driver = { |
197 | .name = "max5522" , |
198 | .of_match_table = max5522_of_match, |
199 | }, |
200 | .probe = max5522_spi_probe, |
201 | .id_table = max5522_ids, |
202 | }; |
203 | module_spi_driver(max5522_spi_driver); |
204 | |
205 | MODULE_AUTHOR("Angelo Dureghello <angelo.dureghello@timesys.com" ); |
206 | MODULE_DESCRIPTION("MAX5522 DAC driver" ); |
207 | MODULE_LICENSE("GPL" ); |
208 | |