1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Maxim MAX11205 16-Bit Delta-Sigma ADC 4 * 5 * Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX1240-max11205.pdf 6 * Copyright (C) 2022 Analog Devices, Inc. 7 * Author: Ramona Bolboaca <ramona.bolboaca@analog.com> 8 */ 9 10 #include <linux/device.h> 11 #include <linux/module.h> 12 #include <linux/regulator/consumer.h> 13 #include <linux/spi/spi.h> 14 15 #include <linux/iio/iio.h> 16 #include <linux/iio/adc/ad_sigma_delta.h> 17 18 #define MAX11205_BIT_SCALE 15 19 #define MAX11205A_OUT_DATA_RATE 116 20 #define MAX11205B_OUT_DATA_RATE 13 21 22 enum max11205_chip_type { 23 TYPE_MAX11205A, 24 TYPE_MAX11205B, 25 }; 26 27 struct max11205_chip_info { 28 unsigned int out_data_rate; 29 const char *name; 30 }; 31 32 struct max11205_state { 33 const struct max11205_chip_info *chip_info; 34 struct regulator *vref; 35 struct ad_sigma_delta sd; 36 }; 37 38 static const struct ad_sigma_delta_info max11205_sigma_delta_info = { 39 .has_registers = false, 40 }; 41 42 static int max11205_read_raw(struct iio_dev *indio_dev, 43 struct iio_chan_spec const *chan, 44 int *val, int *val2, long mask) 45 { 46 struct max11205_state *st = iio_priv(indio_dev); 47 int reg_mv; 48 49 switch (mask) { 50 case IIO_CHAN_INFO_RAW: 51 return ad_sigma_delta_single_conversion(indio_dev, chan, val); 52 case IIO_CHAN_INFO_SCALE: 53 reg_mv = regulator_get_voltage(st->vref); 54 if (reg_mv < 0) 55 return reg_mv; 56 reg_mv /= 1000; 57 *val = reg_mv; 58 *val2 = MAX11205_BIT_SCALE; 59 return IIO_VAL_FRACTIONAL_LOG2; 60 case IIO_CHAN_INFO_SAMP_FREQ: 61 *val = st->chip_info->out_data_rate; 62 return IIO_VAL_INT; 63 default: 64 return -EINVAL; 65 } 66 } 67 68 static const struct iio_info max11205_iio_info = { 69 .read_raw = max11205_read_raw, 70 .validate_trigger = ad_sd_validate_trigger, 71 }; 72 73 static const struct iio_chan_spec max11205_channels[] = { 74 { 75 .type = IIO_VOLTAGE, 76 .indexed = 1, 77 .scan_type = { 78 .sign = 's', 79 .realbits = 16, 80 .storagebits = 16, 81 .endianness = IIO_BE, 82 }, 83 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | 84 BIT(IIO_CHAN_INFO_SAMP_FREQ) | 85 BIT(IIO_CHAN_INFO_SCALE), 86 }, 87 }; 88 89 static const struct max11205_chip_info max11205_chip_info[] = { 90 [TYPE_MAX11205A] = { 91 .out_data_rate = MAX11205A_OUT_DATA_RATE, 92 .name = "max11205a", 93 }, 94 [TYPE_MAX11205B] = { 95 .out_data_rate = MAX11205B_OUT_DATA_RATE, 96 .name = "max11205b", 97 }, 98 }; 99 100 static void max11205_reg_disable(void *reg) 101 { 102 regulator_disable(reg); 103 } 104 105 static int max11205_probe(struct spi_device *spi) 106 { 107 struct max11205_state *st; 108 struct iio_dev *indio_dev; 109 int ret; 110 111 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 112 if (!indio_dev) 113 return -ENOMEM; 114 115 st = iio_priv(indio_dev); 116 117 ad_sd_init(&st->sd, indio_dev, spi, &max11205_sigma_delta_info); 118 119 st->chip_info = spi_get_device_match_data(spi); 120 121 indio_dev->name = st->chip_info->name; 122 indio_dev->modes = INDIO_DIRECT_MODE; 123 indio_dev->channels = max11205_channels; 124 indio_dev->num_channels = 1; 125 indio_dev->info = &max11205_iio_info; 126 127 st->vref = devm_regulator_get(&spi->dev, "vref"); 128 if (IS_ERR(st->vref)) 129 return dev_err_probe(&spi->dev, PTR_ERR(st->vref), 130 "Failed to get vref regulator\n"); 131 132 ret = regulator_enable(st->vref); 133 if (ret) 134 return ret; 135 136 ret = devm_add_action_or_reset(&spi->dev, max11205_reg_disable, st->vref); 137 if (ret) 138 return ret; 139 140 ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev); 141 if (ret) 142 return ret; 143 144 return devm_iio_device_register(&spi->dev, indio_dev); 145 } 146 147 static const struct spi_device_id max11205_spi_ids[] = { 148 { "max11205a", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205A] }, 149 { "max11205b", (kernel_ulong_t)&max11205_chip_info[TYPE_MAX11205B] }, 150 { } 151 }; 152 MODULE_DEVICE_TABLE(spi, max11205_spi_ids); 153 154 static const struct of_device_id max11205_dt_ids[] = { 155 { 156 .compatible = "maxim,max11205a", 157 .data = &max11205_chip_info[TYPE_MAX11205A], 158 }, 159 { 160 .compatible = "maxim,max11205b", 161 .data = &max11205_chip_info[TYPE_MAX11205B], 162 }, 163 { } 164 }; 165 MODULE_DEVICE_TABLE(of, max11205_dt_ids); 166 167 static struct spi_driver max11205_spi_driver = { 168 .driver = { 169 .name = "max11205", 170 .of_match_table = max11205_dt_ids, 171 }, 172 .probe = max11205_probe, 173 .id_table = max11205_spi_ids, 174 }; 175 module_spi_driver(max11205_spi_driver); 176 177 MODULE_AUTHOR("Ramona Bolboaca <ramona.bolboaca@analog.com>"); 178 MODULE_DESCRIPTION("MAX11205 ADC driver"); 179 MODULE_LICENSE("GPL v2"); 180 MODULE_IMPORT_NS(IIO_AD_SIGMA_DELTA); 181