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