273 lines
6.3 KiB
C
273 lines
6.3 KiB
C
/*
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* TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver
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*
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* Copyright (C) 2012 Avionic Design GmbH
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* Copyright (C) 2016 Intel
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Datasheets:
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* http://www.ti.com/lit/ds/symlink/adc081c021.pdf
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* http://www.ti.com/lit/ds/symlink/adc101c021.pdf
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* http://www.ti.com/lit/ds/symlink/adc121c021.pdf
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*
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* The devices have a very similar interface and differ mostly in the number of
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* bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2
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* bits of value registers are reserved.
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*/
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/acpi.h>
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#include <linux/iio/iio.h>
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#include <linux/iio/buffer.h>
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#include <linux/iio/trigger_consumer.h>
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#include <linux/iio/triggered_buffer.h>
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#include <linux/regulator/consumer.h>
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struct adc081c {
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struct i2c_client *i2c;
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struct regulator *ref;
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/* 8, 10 or 12 */
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int bits;
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};
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#define REG_CONV_RES 0x00
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static int adc081c_read_raw(struct iio_dev *iio,
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struct iio_chan_spec const *channel, int *value,
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int *shift, long mask)
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{
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struct adc081c *adc = iio_priv(iio);
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int err;
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switch (mask) {
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case IIO_CHAN_INFO_RAW:
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err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES);
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if (err < 0)
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return err;
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*value = (err & 0xFFF) >> (12 - adc->bits);
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return IIO_VAL_INT;
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case IIO_CHAN_INFO_SCALE:
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err = regulator_get_voltage(adc->ref);
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if (err < 0)
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return err;
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*value = err / 1000;
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*shift = adc->bits;
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return IIO_VAL_FRACTIONAL_LOG2;
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default:
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break;
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}
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return -EINVAL;
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}
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#define ADCxx1C_CHAN(_bits) { \
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.type = IIO_VOLTAGE, \
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.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
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.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
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.scan_type = { \
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.sign = 'u', \
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.realbits = (_bits), \
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.storagebits = 16, \
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.shift = 12 - (_bits), \
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.endianness = IIO_CPU, \
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}, \
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}
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#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \
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static const struct iio_chan_spec _name ## _channels[] = { \
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ADCxx1C_CHAN((_bits)), \
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IIO_CHAN_SOFT_TIMESTAMP(1), \
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}; \
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#define ADC081C_NUM_CHANNELS 2
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struct adcxx1c_model {
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const struct iio_chan_spec* channels;
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int bits;
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};
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#define ADCxx1C_MODEL(_name, _bits) \
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{ \
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.channels = _name ## _channels, \
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.bits = (_bits), \
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}
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DEFINE_ADCxx1C_CHANNELS(adc081c, 8);
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DEFINE_ADCxx1C_CHANNELS(adc101c, 10);
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DEFINE_ADCxx1C_CHANNELS(adc121c, 12);
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/* Model ids are indexes in _models array */
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enum adcxx1c_model_id {
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ADC081C = 0,
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ADC101C = 1,
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ADC121C = 2,
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};
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static struct adcxx1c_model adcxx1c_models[] = {
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ADCxx1C_MODEL(adc081c, 8),
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ADCxx1C_MODEL(adc101c, 10),
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ADCxx1C_MODEL(adc121c, 12),
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};
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static const struct iio_info adc081c_info = {
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.read_raw = adc081c_read_raw,
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};
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static irqreturn_t adc081c_trigger_handler(int irq, void *p)
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{
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struct iio_poll_func *pf = p;
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struct iio_dev *indio_dev = pf->indio_dev;
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struct adc081c *data = iio_priv(indio_dev);
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u16 buf[8]; /* 2 bytes data + 6 bytes padding + 8 bytes timestamp */
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int ret;
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ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES);
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if (ret < 0)
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goto out;
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buf[0] = ret;
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iio_push_to_buffers_with_timestamp(indio_dev, buf,
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iio_get_time_ns(indio_dev));
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out:
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iio_trigger_notify_done(indio_dev->trig);
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return IRQ_HANDLED;
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}
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static int adc081c_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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struct iio_dev *iio;
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struct adc081c *adc;
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struct adcxx1c_model *model;
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int err;
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if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA))
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return -EOPNOTSUPP;
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if (ACPI_COMPANION(&client->dev)) {
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const struct acpi_device_id *ad_id;
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ad_id = acpi_match_device(client->dev.driver->acpi_match_table,
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&client->dev);
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if (!ad_id)
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return -ENODEV;
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model = &adcxx1c_models[ad_id->driver_data];
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} else {
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model = &adcxx1c_models[id->driver_data];
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}
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iio = devm_iio_device_alloc(&client->dev, sizeof(*adc));
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if (!iio)
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return -ENOMEM;
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adc = iio_priv(iio);
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adc->i2c = client;
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adc->bits = model->bits;
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adc->ref = devm_regulator_get(&client->dev, "vref");
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if (IS_ERR(adc->ref))
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return PTR_ERR(adc->ref);
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err = regulator_enable(adc->ref);
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if (err < 0)
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return err;
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iio->dev.parent = &client->dev;
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iio->dev.of_node = client->dev.of_node;
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iio->name = dev_name(&client->dev);
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iio->modes = INDIO_DIRECT_MODE;
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iio->info = &adc081c_info;
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iio->channels = model->channels;
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iio->num_channels = ADC081C_NUM_CHANNELS;
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err = iio_triggered_buffer_setup(iio, NULL, adc081c_trigger_handler, NULL);
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if (err < 0) {
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dev_err(&client->dev, "iio triggered buffer setup failed\n");
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goto err_regulator_disable;
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}
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err = iio_device_register(iio);
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if (err < 0)
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goto err_buffer_cleanup;
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i2c_set_clientdata(client, iio);
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return 0;
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err_buffer_cleanup:
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iio_triggered_buffer_cleanup(iio);
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err_regulator_disable:
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regulator_disable(adc->ref);
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return err;
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}
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static int adc081c_remove(struct i2c_client *client)
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{
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struct iio_dev *iio = i2c_get_clientdata(client);
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struct adc081c *adc = iio_priv(iio);
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iio_device_unregister(iio);
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iio_triggered_buffer_cleanup(iio);
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regulator_disable(adc->ref);
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return 0;
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}
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static const struct i2c_device_id adc081c_id[] = {
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{ "adc081c", ADC081C },
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{ "adc101c", ADC101C },
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{ "adc121c", ADC121C },
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{ }
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};
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MODULE_DEVICE_TABLE(i2c, adc081c_id);
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#ifdef CONFIG_OF
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static const struct of_device_id adc081c_of_match[] = {
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{ .compatible = "ti,adc081c" },
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{ .compatible = "ti,adc101c" },
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{ .compatible = "ti,adc121c" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, adc081c_of_match);
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#endif
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#ifdef CONFIG_ACPI
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static const struct acpi_device_id adc081c_acpi_match[] = {
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{ "ADC081C", ADC081C },
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{ "ADC101C", ADC101C },
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{ "ADC121C", ADC121C },
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{ }
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};
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MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match);
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#endif
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static struct i2c_driver adc081c_driver = {
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.driver = {
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.name = "adc081c",
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.of_match_table = of_match_ptr(adc081c_of_match),
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.acpi_match_table = ACPI_PTR(adc081c_acpi_match),
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},
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.probe = adc081c_probe,
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.remove = adc081c_remove,
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.id_table = adc081c_id,
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};
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module_i2c_driver(adc081c_driver);
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MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>");
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MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver");
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MODULE_LICENSE("GPL v2");
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