diff options
Diffstat (limited to 'drivers/iio/adc/ti-adc081c.c')
| -rw-r--r-- | drivers/iio/adc/ti-adc081c.c | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c new file mode 100644 index 000000000..bd48b073e --- /dev/null +++ b/drivers/iio/adc/ti-adc081c.c @@ -0,0 +1,245 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * TI ADC081C/ADC101C/ADC121C 8/10/12-bit ADC driver + * + * Copyright (C) 2012 Avionic Design GmbH + * Copyright (C) 2016 Intel + * + * Datasheets: + * https://www.ti.com/lit/ds/symlink/adc081c021.pdf + * https://www.ti.com/lit/ds/symlink/adc101c021.pdf + * https://www.ti.com/lit/ds/symlink/adc121c021.pdf + * + * The devices have a very similar interface and differ mostly in the number of + * bits handled. For the 8-bit and 10-bit models the least-significant 4 or 2 + * bits of value registers are reserved. + */ + +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/property.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/regulator/consumer.h> + +struct adc081c { + struct i2c_client *i2c; + struct regulator *ref; + + /* 8, 10 or 12 */ + int bits; + + /* Ensure natural alignment of buffer elements */ + struct { + u16 channel; + s64 ts __aligned(8); + } scan; +}; + +#define REG_CONV_RES 0x00 + +static int adc081c_read_raw(struct iio_dev *iio, + struct iio_chan_spec const *channel, int *value, + int *shift, long mask) +{ + struct adc081c *adc = iio_priv(iio); + int err; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + err = i2c_smbus_read_word_swapped(adc->i2c, REG_CONV_RES); + if (err < 0) + return err; + + *value = (err & 0xFFF) >> (12 - adc->bits); + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + err = regulator_get_voltage(adc->ref); + if (err < 0) + return err; + + *value = err / 1000; + *shift = adc->bits; + + return IIO_VAL_FRACTIONAL_LOG2; + + default: + break; + } + + return -EINVAL; +} + +#define ADCxx1C_CHAN(_bits) { \ + .type = IIO_VOLTAGE, \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .scan_type = { \ + .sign = 'u', \ + .realbits = (_bits), \ + .storagebits = 16, \ + .shift = 12 - (_bits), \ + .endianness = IIO_CPU, \ + }, \ +} + +#define DEFINE_ADCxx1C_CHANNELS(_name, _bits) \ + static const struct iio_chan_spec _name ## _channels[] = { \ + ADCxx1C_CHAN((_bits)), \ + IIO_CHAN_SOFT_TIMESTAMP(1), \ + }; \ + +#define ADC081C_NUM_CHANNELS 2 + +struct adcxx1c_model { + const struct iio_chan_spec* channels; + int bits; +}; + +#define ADCxx1C_MODEL(_name, _bits) \ + { \ + .channels = _name ## _channels, \ + .bits = (_bits), \ + } + +DEFINE_ADCxx1C_CHANNELS(adc081c, 8); +DEFINE_ADCxx1C_CHANNELS(adc101c, 10); +DEFINE_ADCxx1C_CHANNELS(adc121c, 12); + +/* Model ids are indexes in _models array */ +enum adcxx1c_model_id { + ADC081C = 0, + ADC101C = 1, + ADC121C = 2, +}; + +static struct adcxx1c_model adcxx1c_models[] = { + ADCxx1C_MODEL(adc081c, 8), + ADCxx1C_MODEL(adc101c, 10), + ADCxx1C_MODEL(adc121c, 12), +}; + +static const struct iio_info adc081c_info = { + .read_raw = adc081c_read_raw, +}; + +static irqreturn_t adc081c_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct adc081c *data = iio_priv(indio_dev); + int ret; + + ret = i2c_smbus_read_word_swapped(data->i2c, REG_CONV_RES); + if (ret < 0) + goto out; + data->scan.channel = ret; + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan, + iio_get_time_ns(indio_dev)); +out: + iio_trigger_notify_done(indio_dev->trig); + return IRQ_HANDLED; +} + +static void adc081c_reg_disable(void *reg) +{ + regulator_disable(reg); +} + +static int adc081c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *iio; + struct adc081c *adc; + const struct adcxx1c_model *model; + int err; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) + return -EOPNOTSUPP; + + if (dev_fwnode(&client->dev)) + model = device_get_match_data(&client->dev); + else + model = &adcxx1c_models[id->driver_data]; + + iio = devm_iio_device_alloc(&client->dev, sizeof(*adc)); + if (!iio) + return -ENOMEM; + + adc = iio_priv(iio); + adc->i2c = client; + adc->bits = model->bits; + + adc->ref = devm_regulator_get(&client->dev, "vref"); + if (IS_ERR(adc->ref)) + return PTR_ERR(adc->ref); + + err = regulator_enable(adc->ref); + if (err < 0) + return err; + + err = devm_add_action_or_reset(&client->dev, adc081c_reg_disable, + adc->ref); + if (err) + return err; + + iio->name = dev_name(&client->dev); + iio->modes = INDIO_DIRECT_MODE; + iio->info = &adc081c_info; + + iio->channels = model->channels; + iio->num_channels = ADC081C_NUM_CHANNELS; + + err = devm_iio_triggered_buffer_setup(&client->dev, iio, NULL, + adc081c_trigger_handler, NULL); + if (err < 0) { + dev_err(&client->dev, "iio triggered buffer setup failed\n"); + return err; + } + + return devm_iio_device_register(&client->dev, iio); +} + +static const struct i2c_device_id adc081c_id[] = { + { "adc081c", ADC081C }, + { "adc101c", ADC101C }, + { "adc121c", ADC121C }, + { } +}; +MODULE_DEVICE_TABLE(i2c, adc081c_id); + +static const struct acpi_device_id adc081c_acpi_match[] = { + /* Used on some AAEON boards */ + { "ADC081C", (kernel_ulong_t)&adcxx1c_models[ADC081C] }, + { } +}; +MODULE_DEVICE_TABLE(acpi, adc081c_acpi_match); + +static const struct of_device_id adc081c_of_match[] = { + { .compatible = "ti,adc081c", .data = &adcxx1c_models[ADC081C] }, + { .compatible = "ti,adc101c", .data = &adcxx1c_models[ADC101C] }, + { .compatible = "ti,adc121c", .data = &adcxx1c_models[ADC121C] }, + { } +}; +MODULE_DEVICE_TABLE(of, adc081c_of_match); + +static struct i2c_driver adc081c_driver = { + .driver = { + .name = "adc081c", + .of_match_table = adc081c_of_match, + .acpi_match_table = adc081c_acpi_match, + }, + .probe = adc081c_probe, + .id_table = adc081c_id, +}; +module_i2c_driver(adc081c_driver); + +MODULE_AUTHOR("Thierry Reding <thierry.reding@avionic-design.de>"); +MODULE_DESCRIPTION("Texas Instruments ADC081C/ADC101C/ADC121C driver"); +MODULE_LICENSE("GPL v2"); |