1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com> 4 * 5 * Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip. 6 * Datasheets can be found here: 7 * https://www.ti.com/lit/ds/symlink/adc128s052.pdf 8 * https://www.ti.com/lit/ds/symlink/adc122s021.pdf 9 * https://www.ti.com/lit/ds/symlink/adc124s021.pdf 10 */ 11 12 #include <linux/acpi.h> 13 #include <linux/err.h> 14 #include <linux/spi/spi.h> 15 #include <linux/module.h> 16 #include <linux/iio/iio.h> 17 #include <linux/property.h> 18 #include <linux/regulator/consumer.h> 19 20 struct adc128_configuration { 21 const struct iio_chan_spec *channels; 22 u8 num_channels; 23 }; 24 25 struct adc128 { 26 struct spi_device *spi; 27 28 struct regulator *reg; 29 struct mutex lock; 30 31 u8 buffer[2] ____cacheline_aligned; 32 }; 33 34 static int adc128_adc_conversion(struct adc128 *adc, u8 channel) 35 { 36 int ret; 37 38 mutex_lock(&adc->lock); 39 40 adc->buffer[0] = channel << 3; 41 adc->buffer[1] = 0; 42 43 ret = spi_write(adc->spi, &adc->buffer, 2); 44 if (ret < 0) { 45 mutex_unlock(&adc->lock); 46 return ret; 47 } 48 49 ret = spi_read(adc->spi, &adc->buffer, 2); 50 51 mutex_unlock(&adc->lock); 52 53 if (ret < 0) 54 return ret; 55 56 return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF); 57 } 58 59 static int adc128_read_raw(struct iio_dev *indio_dev, 60 struct iio_chan_spec const *channel, int *val, 61 int *val2, long mask) 62 { 63 struct adc128 *adc = iio_priv(indio_dev); 64 int ret; 65 66 switch (mask) { 67 case IIO_CHAN_INFO_RAW: 68 69 ret = adc128_adc_conversion(adc, channel->channel); 70 if (ret < 0) 71 return ret; 72 73 *val = ret; 74 return IIO_VAL_INT; 75 76 case IIO_CHAN_INFO_SCALE: 77 78 ret = regulator_get_voltage(adc->reg); 79 if (ret < 0) 80 return ret; 81 82 *val = ret / 1000; 83 *val2 = 12; 84 return IIO_VAL_FRACTIONAL_LOG2; 85 86 default: 87 return -EINVAL; 88 } 89 90 } 91 92 #define ADC128_VOLTAGE_CHANNEL(num) \ 93 { \ 94 .type = IIO_VOLTAGE, \ 95 .indexed = 1, \ 96 .channel = (num), \ 97 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 98 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ 99 } 100 101 static const struct iio_chan_spec adc128s052_channels[] = { 102 ADC128_VOLTAGE_CHANNEL(0), 103 ADC128_VOLTAGE_CHANNEL(1), 104 ADC128_VOLTAGE_CHANNEL(2), 105 ADC128_VOLTAGE_CHANNEL(3), 106 ADC128_VOLTAGE_CHANNEL(4), 107 ADC128_VOLTAGE_CHANNEL(5), 108 ADC128_VOLTAGE_CHANNEL(6), 109 ADC128_VOLTAGE_CHANNEL(7), 110 }; 111 112 static const struct iio_chan_spec adc122s021_channels[] = { 113 ADC128_VOLTAGE_CHANNEL(0), 114 ADC128_VOLTAGE_CHANNEL(1), 115 }; 116 117 static const struct iio_chan_spec adc124s021_channels[] = { 118 ADC128_VOLTAGE_CHANNEL(0), 119 ADC128_VOLTAGE_CHANNEL(1), 120 ADC128_VOLTAGE_CHANNEL(2), 121 ADC128_VOLTAGE_CHANNEL(3), 122 }; 123 124 static const struct adc128_configuration adc128_config[] = { 125 { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) }, 126 { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) }, 127 { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) }, 128 }; 129 130 static const struct iio_info adc128_info = { 131 .read_raw = adc128_read_raw, 132 }; 133 134 static int adc128_probe(struct spi_device *spi) 135 { 136 struct iio_dev *indio_dev; 137 unsigned int config; 138 struct adc128 *adc; 139 int ret; 140 141 if (dev_fwnode(&spi->dev)) 142 config = (unsigned long) device_get_match_data(&spi->dev); 143 else 144 config = spi_get_device_id(spi)->driver_data; 145 146 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); 147 if (!indio_dev) 148 return -ENOMEM; 149 150 adc = iio_priv(indio_dev); 151 adc->spi = spi; 152 153 spi_set_drvdata(spi, indio_dev); 154 155 indio_dev->name = spi_get_device_id(spi)->name; 156 indio_dev->modes = INDIO_DIRECT_MODE; 157 indio_dev->info = &adc128_info; 158 159 indio_dev->channels = adc128_config[config].channels; 160 indio_dev->num_channels = adc128_config[config].num_channels; 161 162 adc->reg = devm_regulator_get(&spi->dev, "vref"); 163 if (IS_ERR(adc->reg)) 164 return PTR_ERR(adc->reg); 165 166 ret = regulator_enable(adc->reg); 167 if (ret < 0) 168 return ret; 169 170 mutex_init(&adc->lock); 171 172 ret = iio_device_register(indio_dev); 173 174 return ret; 175 } 176 177 static int adc128_remove(struct spi_device *spi) 178 { 179 struct iio_dev *indio_dev = spi_get_drvdata(spi); 180 struct adc128 *adc = iio_priv(indio_dev); 181 182 iio_device_unregister(indio_dev); 183 regulator_disable(adc->reg); 184 185 return 0; 186 } 187 188 static const struct of_device_id adc128_of_match[] = { 189 { .compatible = "ti,adc128s052", }, 190 { .compatible = "ti,adc122s021", }, 191 { .compatible = "ti,adc122s051", }, 192 { .compatible = "ti,adc122s101", }, 193 { .compatible = "ti,adc124s021", }, 194 { .compatible = "ti,adc124s051", }, 195 { .compatible = "ti,adc124s101", }, 196 { /* sentinel */ }, 197 }; 198 MODULE_DEVICE_TABLE(of, adc128_of_match); 199 200 static const struct spi_device_id adc128_id[] = { 201 { "adc128s052", 0 }, /* index into adc128_config */ 202 { "adc122s021", 1 }, 203 { "adc122s051", 1 }, 204 { "adc122s101", 1 }, 205 { "adc124s021", 2 }, 206 { "adc124s051", 2 }, 207 { "adc124s101", 2 }, 208 { } 209 }; 210 MODULE_DEVICE_TABLE(spi, adc128_id); 211 212 #ifdef CONFIG_ACPI 213 static const struct acpi_device_id adc128_acpi_match[] = { 214 { "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */ 215 { } 216 }; 217 MODULE_DEVICE_TABLE(acpi, adc128_acpi_match); 218 #endif 219 220 static struct spi_driver adc128_driver = { 221 .driver = { 222 .name = "adc128s052", 223 .of_match_table = of_match_ptr(adc128_of_match), 224 .acpi_match_table = ACPI_PTR(adc128_acpi_match), 225 }, 226 .probe = adc128_probe, 227 .remove = adc128_remove, 228 .id_table = adc128_id, 229 }; 230 module_spi_driver(adc128_driver); 231 232 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>"); 233 MODULE_DESCRIPTION("Texas Instruments ADC128S052"); 234 MODULE_LICENSE("GPL v2"); 235