1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2022 Analog Devices, Inc.
4 * ADI MAX77541 ADC Driver with IIO interface
5 */
6
7 #include <linux/bitfield.h>
8 #include <linux/iio/iio.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/platform_device.h>
11 #include <linux/regmap.h>
12 #include <linux/units.h>
13
14 #include <linux/mfd/max77541.h>
15
16 enum max77541_adc_range {
17 LOW_RANGE,
18 MID_RANGE,
19 HIGH_RANGE,
20 };
21
22 enum max77541_adc_channel {
23 MAX77541_ADC_VSYS_V,
24 MAX77541_ADC_VOUT1_V,
25 MAX77541_ADC_VOUT2_V,
26 MAX77541_ADC_TEMP,
27 };
28
max77541_adc_offset(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2)29 static int max77541_adc_offset(struct iio_dev *indio_dev,
30 struct iio_chan_spec const *chan,
31 int *val, int *val2)
32 {
33 switch (chan->channel) {
34 case MAX77541_ADC_TEMP:
35 *val = DIV_ROUND_CLOSEST(ABSOLUTE_ZERO_MILLICELSIUS, 1725);
36 return IIO_VAL_INT;
37 default:
38 return -EINVAL;
39 }
40 }
41
max77541_adc_scale(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2)42 static int max77541_adc_scale(struct iio_dev *indio_dev,
43 struct iio_chan_spec const *chan,
44 int *val, int *val2)
45 {
46 struct regmap **regmap = iio_priv(indio_dev);
47 unsigned int reg_val;
48 int ret;
49
50 switch (chan->channel) {
51 case MAX77541_ADC_VSYS_V:
52 *val = 25;
53 return IIO_VAL_INT;
54 case MAX77541_ADC_VOUT1_V:
55 case MAX77541_ADC_VOUT2_V:
56 ret = regmap_read(*regmap, MAX77541_REG_M2_CFG1, ®_val);
57 if (ret)
58 return ret;
59
60 reg_val = FIELD_GET(MAX77541_BITS_MX_CFG1_RNG, reg_val);
61 switch (reg_val) {
62 case LOW_RANGE:
63 *val = 6;
64 *val2 = 250000;
65 break;
66 case MID_RANGE:
67 *val = 12;
68 *val2 = 500000;
69 break;
70 case HIGH_RANGE:
71 *val = 25;
72 return IIO_VAL_INT;
73 default:
74 return -EINVAL;
75 }
76
77 return IIO_VAL_INT_PLUS_MICRO;
78 case MAX77541_ADC_TEMP:
79 *val = 1725;
80 return IIO_VAL_INT;
81 default:
82 return -EINVAL;
83 }
84 }
85
max77541_adc_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val)86 static int max77541_adc_raw(struct iio_dev *indio_dev,
87 struct iio_chan_spec const *chan,
88 int *val)
89 {
90 struct regmap **regmap = iio_priv(indio_dev);
91 int ret;
92
93 ret = regmap_read(*regmap, chan->address, val);
94 if (ret)
95 return ret;
96
97 return IIO_VAL_INT;
98 }
99
100 #define MAX77541_ADC_CHANNEL_V(_channel, _name, _type, _reg) \
101 { \
102 .type = _type, \
103 .indexed = 1, \
104 .channel = _channel, \
105 .address = _reg, \
106 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
107 BIT(IIO_CHAN_INFO_SCALE), \
108 .datasheet_name = _name, \
109 }
110
111 #define MAX77541_ADC_CHANNEL_TEMP(_channel, _name, _type, _reg) \
112 { \
113 .type = _type, \
114 .indexed = 1, \
115 .channel = _channel, \
116 .address = _reg, \
117 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
118 BIT(IIO_CHAN_INFO_SCALE) |\
119 BIT(IIO_CHAN_INFO_OFFSET),\
120 .datasheet_name = _name, \
121 }
122
123 static const struct iio_chan_spec max77541_adc_channels[] = {
124 MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VSYS_V, "vsys_v", IIO_VOLTAGE,
125 MAX77541_REG_ADC_DATA_CH1),
126 MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT1_V, "vout1_v", IIO_VOLTAGE,
127 MAX77541_REG_ADC_DATA_CH2),
128 MAX77541_ADC_CHANNEL_V(MAX77541_ADC_VOUT2_V, "vout2_v", IIO_VOLTAGE,
129 MAX77541_REG_ADC_DATA_CH3),
130 MAX77541_ADC_CHANNEL_TEMP(MAX77541_ADC_TEMP, "temp", IIO_TEMP,
131 MAX77541_REG_ADC_DATA_CH6),
132 };
133
max77541_adc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)134 static int max77541_adc_read_raw(struct iio_dev *indio_dev,
135 struct iio_chan_spec const *chan,
136 int *val, int *val2, long mask)
137 {
138 switch (mask) {
139 case IIO_CHAN_INFO_OFFSET:
140 return max77541_adc_offset(indio_dev, chan, val, val2);
141 case IIO_CHAN_INFO_SCALE:
142 return max77541_adc_scale(indio_dev, chan, val, val2);
143 case IIO_CHAN_INFO_RAW:
144 return max77541_adc_raw(indio_dev, chan, val);
145 default:
146 return -EINVAL;
147 }
148 }
149
150 static const struct iio_info max77541_adc_info = {
151 .read_raw = max77541_adc_read_raw,
152 };
153
max77541_adc_probe(struct platform_device * pdev)154 static int max77541_adc_probe(struct platform_device *pdev)
155 {
156 struct device *dev = &pdev->dev;
157 struct iio_dev *indio_dev;
158 struct regmap **regmap;
159
160 indio_dev = devm_iio_device_alloc(dev, sizeof(*regmap));
161 if (!indio_dev)
162 return -ENOMEM;
163
164 regmap = iio_priv(indio_dev);
165
166 *regmap = dev_get_regmap(dev->parent, NULL);
167 indio_dev->modes = INDIO_DIRECT_MODE;
168
169 indio_dev->name = "max77541";
170 indio_dev->info = &max77541_adc_info;
171 indio_dev->channels = max77541_adc_channels;
172 indio_dev->num_channels = ARRAY_SIZE(max77541_adc_channels);
173
174 return devm_iio_device_register(dev, indio_dev);
175 }
176
177 static const struct platform_device_id max77541_adc_platform_id[] = {
178 { "max77541-adc" },
179 { /* sentinel */ }
180 };
181 MODULE_DEVICE_TABLE(platform, max77541_adc_platform_id);
182
183 static struct platform_driver max77541_adc_driver = {
184 .driver = {
185 .name = "max77541-adc",
186 },
187 .probe = max77541_adc_probe,
188 .id_table = max77541_adc_platform_id,
189 };
190 module_platform_driver(max77541_adc_driver);
191
192 MODULE_AUTHOR("Okan Sahin <Okan.Sahin@analog.com>");
193 MODULE_DESCRIPTION("MAX77541 ADC driver");
194 MODULE_LICENSE("GPL");
195
