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/mod_devicetable.h> 17 #include <linux/iio/iio.h> 18 #include <linux/property.h> 19 #include <linux/regulator/consumer.h> 20 21 struct adc128_configuration { 22 const struct iio_chan_spec *channels; 23 u8 num_channels; 24 }; 25 26 struct adc128 { 27 struct spi_device *spi; 28 29 struct regulator *reg; 30 struct mutex lock; 31 32 u8 buffer[2] __aligned(IIO_DMA_MINALIGN); 33 }; 34 35 static int adc128_adc_conversion(struct adc128 *adc, u8 channel) 36 { 37 int ret; 38 39 mutex_lock(&adc->lock); 40 41 adc->buffer[0] = channel << 3; 42 adc->buffer[1] = 0; 43 44 ret = spi_write(adc->spi, &adc->buffer, 2); 45 if (ret < 0) { 46 mutex_unlock(&adc->lock); 47 return ret; 48 } 49 50 ret = spi_read(adc->spi, &adc->buffer, 2); 51 52 mutex_unlock(&adc->lock); 53 54 if (ret < 0) 55 return ret; 56 57 return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF); 58 } 59 60 static int adc128_read_raw(struct iio_dev *indio_dev, 61 struct iio_chan_spec const *channel, int *val, 62 int *val2, long mask) 63 { 64 struct adc128 *adc = iio_priv(indio_dev); 65 int ret; 66 67 switch (mask) { 68 case IIO_CHAN_INFO_RAW: 69 70 ret = adc128_adc_conversion(adc, channel->channel); 71 if (ret < 0) 72 return ret; 73 74 *val = ret; 75 return IIO_VAL_INT; 76 77 case IIO_CHAN_INFO_SCALE: 78 79 ret = regulator_get_voltage(adc->reg); 80 if (ret < 0) 81 return ret; 82 83 *val = ret / 1000; 84 *val2 = 12; 85 return IIO_VAL_FRACTIONAL_LOG2; 86 87 default: 88 return -EINVAL; 89 } 90 91 } 92 93 #define ADC128_VOLTAGE_CHANNEL(num) \ 94 { \ 95 .type = IIO_VOLTAGE, \ 96 .indexed = 1, \ 97 .channel = (num), \ 98 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 99 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ 100 } 101 102 static const struct iio_chan_spec adc128s052_channels[] = { 103 ADC128_VOLTAGE_CHANNEL(0), 104 ADC128_VOLTAGE_CHANNEL(1), 105 ADC128_VOLTAGE_CHANNEL(2), 106 ADC128_VOLTAGE_CHANNEL(3), 107 ADC128_VOLTAGE_CHANNEL(4), 108 ADC128_VOLTAGE_CHANNEL(5), 109 ADC128_VOLTAGE_CHANNEL(6), 110 ADC128_VOLTAGE_CHANNEL(7), 111 }; 112 113 static const struct iio_chan_spec adc122s021_channels[] = { 114 ADC128_VOLTAGE_CHANNEL(0), 115 ADC128_VOLTAGE_CHANNEL(1), 116 }; 117 118 static const struct iio_chan_spec adc124s021_channels[] = { 119 ADC128_VOLTAGE_CHANNEL(0), 120 ADC128_VOLTAGE_CHANNEL(1), 121 ADC128_VOLTAGE_CHANNEL(2), 122 ADC128_VOLTAGE_CHANNEL(3), 123 }; 124 125 static const struct adc128_configuration adc128_config[] = { 126 { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) }, 127 { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) }, 128 { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) }, 129 }; 130 131 static const struct iio_info adc128_info = { 132 .read_raw = adc128_read_raw, 133 }; 134 135 static void adc128_disable_regulator(void *reg) 136 { 137 regulator_disable(reg); 138 } 139 140 static int adc128_probe(struct spi_device *spi) 141 { 142 struct iio_dev *indio_dev; 143 unsigned int config; 144 struct adc128 *adc; 145 int ret; 146 147 if (dev_fwnode(&spi->dev)) 148 config = (unsigned long) device_get_match_data(&spi->dev); 149 else 150 config = spi_get_device_id(spi)->driver_data; 151 152 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); 153 if (!indio_dev) 154 return -ENOMEM; 155 156 adc = iio_priv(indio_dev); 157 adc->spi = spi; 158 159 indio_dev->name = spi_get_device_id(spi)->name; 160 indio_dev->modes = INDIO_DIRECT_MODE; 161 indio_dev->info = &adc128_info; 162 163 indio_dev->channels = adc128_config[config].channels; 164 indio_dev->num_channels = adc128_config[config].num_channels; 165 166 adc->reg = devm_regulator_get(&spi->dev, "vref"); 167 if (IS_ERR(adc->reg)) 168 return PTR_ERR(adc->reg); 169 170 ret = regulator_enable(adc->reg); 171 if (ret < 0) 172 return ret; 173 ret = devm_add_action_or_reset(&spi->dev, adc128_disable_regulator, 174 adc->reg); 175 if (ret) 176 return ret; 177 178 mutex_init(&adc->lock); 179 180 return devm_iio_device_register(&spi->dev, indio_dev); 181 } 182 183 static const struct of_device_id adc128_of_match[] = { 184 { .compatible = "ti,adc128s052", }, 185 { .compatible = "ti,adc122s021", }, 186 { .compatible = "ti,adc122s051", }, 187 { .compatible = "ti,adc122s101", }, 188 { .compatible = "ti,adc124s021", }, 189 { .compatible = "ti,adc124s051", }, 190 { .compatible = "ti,adc124s101", }, 191 { /* sentinel */ }, 192 }; 193 MODULE_DEVICE_TABLE(of, adc128_of_match); 194 195 static const struct spi_device_id adc128_id[] = { 196 { "adc128s052", 0 }, /* index into adc128_config */ 197 { "adc122s021", 1 }, 198 { "adc122s051", 1 }, 199 { "adc122s101", 1 }, 200 { "adc124s021", 2 }, 201 { "adc124s051", 2 }, 202 { "adc124s101", 2 }, 203 { } 204 }; 205 MODULE_DEVICE_TABLE(spi, adc128_id); 206 207 #ifdef CONFIG_ACPI 208 static const struct acpi_device_id adc128_acpi_match[] = { 209 { "AANT1280", 2 }, /* ADC124S021 compatible ACPI ID */ 210 { } 211 }; 212 MODULE_DEVICE_TABLE(acpi, adc128_acpi_match); 213 #endif 214 215 static struct spi_driver adc128_driver = { 216 .driver = { 217 .name = "adc128s052", 218 .of_match_table = adc128_of_match, 219 .acpi_match_table = ACPI_PTR(adc128_acpi_match), 220 }, 221 .probe = adc128_probe, 222 .id_table = adc128_id, 223 }; 224 module_spi_driver(adc128_driver); 225 226 MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>"); 227 MODULE_DESCRIPTION("Texas Instruments ADC128S052"); 228 MODULE_LICENSE("GPL v2"); 229