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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver4 *5 * Copyright (C) 2012 Avionic Design GmbH6 * Copyright (C) 2016 Intel7 *8 * Datasheets:9 * https://www.ti.com/lit/ds/symlink/adc081c021.pdf10 * https://www.ti.com/lit/ds/symlink/adc101c021.pdf11 * https://www.ti.com/lit/ds/symlink/adc121c021.pdf12 *13 * The devices have a very similar interface and differ mostly in the number of14 * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 215 * bits of value registers are reserved.16 */17 18#include <linux/err.h>19#include <linux/i2c.h>20#include <linux/module.h>21#include <linux/mod_devicetable.h>22#include <linux/property.h>23 24#include <linux/iio/iio.h>25#include <linux/iio/buffer.h>26#include <linux/iio/trigger_consumer.h>27#include <linux/iio/triggered_buffer.h>28#include <linux/regulator/consumer.h>29 30struct adc081c {31 struct i2c_client *i2c;32 struct regulator *ref;33 34 /* 8, 10 or 12 */35 int bits;36 37 /* Ensure natural alignment of buffer elements */38 struct {39 u16 channel;40 s64 ts __aligned(8);41 } scan;42};43 44#define REG_CONV_RES 0x0045 46static int adc081c_read_raw(struct iio_dev *iio,47 struct iio_chan_spec const *channel, int *value,48 int *shift, long mask)49{50 struct adc081c *adc = iio_priv(iio);51 int err;52 53 switch (mask) {54 case IIO_CHAN_INFO_RAW:55 err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);56 if (err < 0)57 return err;58 59 *value = (err & 0xFFF) >> (12 - adc->bits);60 return IIO_VAL_INT;61 62 case IIO_CHAN_INFO_SCALE:63 err = regulator_get_voltage(adc->ref);64 if (err < 0)65 return err;66 67 *value = err / 1000;68 *shift = adc->bits;69 70 return IIO_VAL_FRACTIONAL_LOG2;71 72 default:73 break;74 }75 76 return -EINVAL;77}78 79#define ADCxx1C_CHAN(_bits) { \80 .type = IIO_VOLTAGE, \81 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \82 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \83 .scan_type = { \84 .sign = 'u', \85 .realbits = (_bits), \86 .storagebits = 16, \87 .shift = 12 - (_bits), \88 .endianness = IIO_CPU, \89 }, \90}91 92#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \93 static const struct iio_chan_spec _name ## _channels[] = { \94 ADCxx1C_CHAN((_bits)), \95 IIO_CHAN_SOFT_TIMESTAMP(1), \96 }; \97 98#define ADC081C_NUM_CHANNELS 299 100struct adcxx1c_model {101 const struct iio_chan_spec* channels;102 int bits;103};104 105#define ADCxx1C_MODEL(_name, _bits) \106 { \107 .channels = _name ## _channels, \108 .bits = (_bits), \109 }110 111DEFINE_ADCxx1C_CHANNELS(adc081c, 8);112DEFINE_ADCxx1C_CHANNELS(adc101c, 10);113DEFINE_ADCxx1C_CHANNELS(adc121c, 12);114 115/* Model ids are indexes in _models array */116enum adcxx1c_model_id {117 ADC081C = 0,118 ADC101C = 1,119 ADC121C = 2,120};121 122static struct adcxx1c_model adcxx1c_models[] = {123 ADCxx1C_MODEL(adc081c, 8),124 ADCxx1C_MODEL(adc101c, 10),125 ADCxx1C_MODEL(adc121c, 12),126};127 128static const struct iio_info adc081c_info = {129 .read_raw = adc081c_read_raw,130};131 132static irqreturn_t adc081c_trigger_handler(int irq, void *p)133{134 struct iio_poll_func *pf = p;135 struct iio_dev *indio_dev = pf->indio_dev;136 struct adc081c *data = iio_priv(indio_dev);137 int ret;138 139 ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);140 if (ret < 0)141 goto out;142 data->scan.channel = ret;143 iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,144 iio_get_time_ns(indio_dev));145out:146 iio_trigger_notify_done(indio_dev->trig);147 return IRQ_HANDLED;148}149 150static void adc081c_reg_disable(void *reg)151{152 regulator_disable(reg);153}154 155static int adc081c_probe(struct i2c_client *client)156{157 struct iio_dev *iio;158 struct adc081c *adc;159 const struct adcxx1c_model *model;160 int err;161 162 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))163 return -EOPNOTSUPP;164 165 model = i2c_get_match_data(client);166 167 iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));168 if (!iio)169 return -ENOMEM;170 171 adc = iio_priv(iio);172 adc->i2c = client;173 adc->bits = model->bits;174 175 adc->ref = devm_regulator_get(&client->dev, "vref");176 if (IS_ERR(adc->ref))177 return PTR_ERR(adc->ref);178 179 err = regulator_enable(adc->ref);180 if (err < 0)181 return err;182 183 err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable,184 adc->ref);185 if (err)186 return err;187 188 iio->name = dev_name(&client->dev);189 iio->modes = INDIO_DIRECT_MODE;190 iio->info = &adc081c_info;191 192 iio->channels = model->channels;193 iio->num_channels = ADC081C_NUM_CHANNELS;194 195 err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL,196 adc081c_trigger_handler, NULL);197 if (err < 0) {198 dev_err(&client->dev, "iio triggered buffer setup failed\n");199 return err;200 }201 202 return devm_iio_device_register(&client->dev, iio);203}204 205static const struct i2c_device_id adc081c_id[] = {206 { "adc081c", (kernel_ulong_t)&adcxx1c_models[ADC081C] },207 { "adc101c", (kernel_ulong_t)&adcxx1c_models[ADC101C] },208 { "adc121c", (kernel_ulong_t)&adcxx1c_models[ADC121C] },209 { }210};211MODULE_DEVICE_TABLE(i2c, adc081c_id);212 213static const struct acpi_device_id adc081c_acpi_match[] = {214 /* Used on some AAEON boards */215 { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] },216 { }217};218MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);219 220static const struct of_device_id adc081c_of_match[] = {221 { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] },222 { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] },223 { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] },224 { }225};226MODULE_DEVICE_TABLE(of, adc081c_of_match);227 228static struct i2c_driver adc081c_driver = {229 .driver = {230 .name = "adc081c",231 .of_match_table = adc081c_of_match,232 .acpi_match_table = adc081c_acpi_match,233 },234 .probe = adc081c_probe,235 .id_table = adc081c_id,236};237module_i2c_driver(adc081c_driver);238 239MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");240MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");241MODULE_LICENSE("GPL v2");242