| /* |
| * Copyright (C) 2014 Angelo Compagnucci <angelo.compagnucci@gmail.com> |
| * |
| * Driver for Texas Instruments' ADC128S052, ADC122S021 and ADC124S021 ADC chip. |
| * Datasheets can be found here: |
| * http://www.ti.com/lit/ds/symlink/adc128s052.pdf |
| * http://www.ti.com/lit/ds/symlink/adc122s021.pdf |
| * http://www.ti.com/lit/ds/symlink/adc124s021.pdf |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/spi/spi.h> |
| #include <linux/module.h> |
| #include <linux/iio/iio.h> |
| #include <linux/regulator/consumer.h> |
| |
| struct adc128_configuration { |
| const struct iio_chan_spec *channels; |
| u8 num_channels; |
| }; |
| |
| struct adc128 { |
| struct spi_device *spi; |
| |
| struct regulator *reg; |
| struct mutex lock; |
| |
| u8 buffer[2] ____cacheline_aligned; |
| }; |
| |
| static int adc128_adc_conversion(struct adc128 *adc, u8 channel) |
| { |
| int ret; |
| |
| mutex_lock(&adc->lock); |
| |
| adc->buffer[0] = channel << 3; |
| adc->buffer[1] = 0; |
| |
| ret = spi_write(adc->spi, &adc->buffer, 2); |
| if (ret < 0) { |
| mutex_unlock(&adc->lock); |
| return ret; |
| } |
| |
| ret = spi_read(adc->spi, &adc->buffer, 2); |
| |
| mutex_unlock(&adc->lock); |
| |
| if (ret < 0) |
| return ret; |
| |
| return ((adc->buffer[0] << 8 | adc->buffer[1]) & 0xFFF); |
| } |
| |
| static int adc128_read_raw(struct iio_dev *indio_dev, |
| struct iio_chan_spec const *channel, int *val, |
| int *val2, long mask) |
| { |
| struct adc128 *adc = iio_priv(indio_dev); |
| int ret; |
| |
| switch (mask) { |
| case IIO_CHAN_INFO_RAW: |
| |
| ret = adc128_adc_conversion(adc, channel->channel); |
| if (ret < 0) |
| return ret; |
| |
| *val = ret; |
| return IIO_VAL_INT; |
| |
| case IIO_CHAN_INFO_SCALE: |
| |
| ret = regulator_get_voltage(adc->reg); |
| if (ret < 0) |
| return ret; |
| |
| *val = ret / 1000; |
| *val2 = 12; |
| return IIO_VAL_FRACTIONAL_LOG2; |
| |
| default: |
| return -EINVAL; |
| } |
| |
| } |
| |
| #define ADC128_VOLTAGE_CHANNEL(num) \ |
| { \ |
| .type = IIO_VOLTAGE, \ |
| .indexed = 1, \ |
| .channel = (num), \ |
| .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ |
| } |
| |
| static const struct iio_chan_spec adc128s052_channels[] = { |
| ADC128_VOLTAGE_CHANNEL(0), |
| ADC128_VOLTAGE_CHANNEL(1), |
| ADC128_VOLTAGE_CHANNEL(2), |
| ADC128_VOLTAGE_CHANNEL(3), |
| ADC128_VOLTAGE_CHANNEL(4), |
| ADC128_VOLTAGE_CHANNEL(5), |
| ADC128_VOLTAGE_CHANNEL(6), |
| ADC128_VOLTAGE_CHANNEL(7), |
| }; |
| |
| static const struct iio_chan_spec adc122s021_channels[] = { |
| ADC128_VOLTAGE_CHANNEL(0), |
| ADC128_VOLTAGE_CHANNEL(1), |
| }; |
| |
| static const struct iio_chan_spec adc124s021_channels[] = { |
| ADC128_VOLTAGE_CHANNEL(0), |
| ADC128_VOLTAGE_CHANNEL(1), |
| ADC128_VOLTAGE_CHANNEL(2), |
| ADC128_VOLTAGE_CHANNEL(3), |
| }; |
| |
| static const struct adc128_configuration adc128_config[] = { |
| { adc128s052_channels, ARRAY_SIZE(adc128s052_channels) }, |
| { adc122s021_channels, ARRAY_SIZE(adc122s021_channels) }, |
| { adc124s021_channels, ARRAY_SIZE(adc124s021_channels) }, |
| }; |
| |
| static const struct iio_info adc128_info = { |
| .read_raw = adc128_read_raw, |
| }; |
| |
| static int adc128_probe(struct spi_device *spi) |
| { |
| struct iio_dev *indio_dev; |
| struct adc128 *adc; |
| int config = spi_get_device_id(spi)->driver_data; |
| int ret; |
| |
| indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); |
| if (!indio_dev) |
| return -ENOMEM; |
| |
| adc = iio_priv(indio_dev); |
| adc->spi = spi; |
| |
| spi_set_drvdata(spi, indio_dev); |
| |
| indio_dev->dev.parent = &spi->dev; |
| indio_dev->dev.of_node = spi->dev.of_node; |
| indio_dev->name = spi_get_device_id(spi)->name; |
| indio_dev->modes = INDIO_DIRECT_MODE; |
| indio_dev->info = &adc128_info; |
| |
| indio_dev->channels = adc128_config[config].channels; |
| indio_dev->num_channels = adc128_config[config].num_channels; |
| |
| adc->reg = devm_regulator_get(&spi->dev, "vref"); |
| if (IS_ERR(adc->reg)) |
| return PTR_ERR(adc->reg); |
| |
| ret = regulator_enable(adc->reg); |
| if (ret < 0) |
| return ret; |
| |
| mutex_init(&adc->lock); |
| |
| ret = iio_device_register(indio_dev); |
| if (ret) |
| goto err_disable_regulator; |
| |
| return 0; |
| |
| err_disable_regulator: |
| regulator_disable(adc->reg); |
| return ret; |
| } |
| |
| static int adc128_remove(struct spi_device *spi) |
| { |
| struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| struct adc128 *adc = iio_priv(indio_dev); |
| |
| iio_device_unregister(indio_dev); |
| regulator_disable(adc->reg); |
| |
| return 0; |
| } |
| |
| static const struct of_device_id adc128_of_match[] = { |
| { .compatible = "ti,adc128s052", }, |
| { .compatible = "ti,adc122s021", }, |
| { .compatible = "ti,adc124s021", }, |
| { /* sentinel */ }, |
| }; |
| MODULE_DEVICE_TABLE(of, adc128_of_match); |
| |
| static const struct spi_device_id adc128_id[] = { |
| { "adc128s052", 0}, /* index into adc128_config */ |
| { "adc122s021", 1}, |
| { "adc124s021", 2}, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(spi, adc128_id); |
| |
| static struct spi_driver adc128_driver = { |
| .driver = { |
| .name = "adc128s052", |
| .of_match_table = of_match_ptr(adc128_of_match), |
| }, |
| .probe = adc128_probe, |
| .remove = adc128_remove, |
| .id_table = adc128_id, |
| }; |
| module_spi_driver(adc128_driver); |
| |
| MODULE_AUTHOR("Angelo Compagnucci <angelo.compagnucci@gmail.com>"); |
| MODULE_DESCRIPTION("Texas Instruments ADC128S052"); |
| MODULE_LICENSE("GPL v2"); |