From bc0a409c5ffd91b5403037ab2798b84dccee4f06 Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 23 Nov 2012 15:13:00 +0000 Subject: [PATCH] iio: adc: Add Texas Instruments ADC081C021/027 support Add support for reading conversion results from the ADC and provide them through a single IIO channel. A proper scaling factor is also exported based on the reference voltage provided by a regulator. Signed-off-by: Thierry Reding Reviewed-by: Lars-Peter Clausen Signed-off-by: Jonathan Cameron --- drivers/iio/adc/Kconfig | 10 +++ drivers/iio/adc/Makefile | 2 + drivers/iio/adc/ti-adc081c.c | 161 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 173 insertions(+) create mode 100644 drivers/iio/adc/ti-adc081c.c diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index 408557b..961b8d0 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -115,4 +115,14 @@ config MAX1363 max11646, max11647) Provides direct access via sysfs and buffered data via the iio dev interface. +config TI_ADC081C + tristate "Texas Instruments ADC081C021/027" + depends on I2C + help + If you say yes here you get support for Texas Instruments ADC081C021 + and ADC081C027 ADC chips. + + This driver can also be built as a module. If so, the module will be + called ti-adc081c. + endmenu diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 78202d9e..472fd7c 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -12,3 +12,5 @@ obj-$(CONFIG_AD7887) += ad7887.o obj-$(CONFIG_AT91_ADC) += at91_adc.o obj-$(CONFIG_LP8788_ADC) += lp8788_adc.o obj-$(CONFIG_MAX1363) += max1363.o +obj-$(CONFIG_TI_ADC081C) += ti-adc081c.o + diff --git a/drivers/iio/adc/ti-adc081c.c b/drivers/iio/adc/ti-adc081c.c new file mode 100644 index 0000000..f4a46dd --- /dev/null +++ b/drivers/iio/adc/ti-adc081c.c @@ -0,0 +1,161 @@ +/* + * Copyright (C) 2012 Avionic Design GmbH + * + * 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 +#include +#include + +#include +#include + +struct adc081c { + struct i2c_client *i2c; + struct regulator *ref; +}; + +#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 >> 4) & 0xff; + return IIO_VAL_INT; + + case IIO_CHAN_INFO_SCALE: + err = regulator_get_voltage(adc->ref); + if (err < 0) + return err; + + *value = err / 1000; + *shift = 8; + + return IIO_VAL_FRACTIONAL_LOG2; + + default: + break; + } + + return -EINVAL; +} + +static const struct iio_chan_spec adc081c_channel = { + .type = IIO_VOLTAGE, + .info_mask = IIO_CHAN_INFO_SCALE_SHARED_BIT | + IIO_CHAN_INFO_RAW_SEPARATE_BIT, +}; + +static const struct iio_info adc081c_info = { + .read_raw = adc081c_read_raw, + .driver_module = THIS_MODULE, +}; + +static int adc081c_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct iio_dev *iio; + struct adc081c *adc; + int err; + + if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA)) + return -ENODEV; + + iio = iio_device_alloc(sizeof(*adc)); + if (!iio) + return -ENOMEM; + + adc = iio_priv(iio); + adc->i2c = client; + + adc->ref = regulator_get(&client->dev, "vref"); + if (IS_ERR(adc->ref)) { + err = PTR_ERR(adc->ref); + goto iio_free; + } + + err = regulator_enable(adc->ref); + if (err < 0) + goto regulator_put; + + iio->dev.parent = &client->dev; + iio->name = dev_name(&client->dev); + iio->modes = INDIO_DIRECT_MODE; + iio->info = &adc081c_info; + + iio->channels = &adc081c_channel; + iio->num_channels = 1; + + err = iio_device_register(iio); + if (err < 0) + goto regulator_disable; + + i2c_set_clientdata(client, iio); + + return 0; + +regulator_disable: + regulator_disable(adc->ref); +regulator_put: + regulator_put(adc->ref); +iio_free: + iio_device_free(iio); + + return err; +} + +static int adc081c_remove(struct i2c_client *client) +{ + struct iio_dev *iio = i2c_get_clientdata(client); + struct adc081c *adc = iio_priv(iio); + + iio_device_unregister(iio); + regulator_disable(adc->ref); + regulator_put(adc->ref); + iio_device_free(iio); + + return 0; +} + +static const struct i2c_device_id adc081c_id[] = { + { "adc081c", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, adc081c_id); + +#ifdef CONFIG_OF +static const struct of_device_id adc081c_of_match[] = { + { .compatible = "ti,adc081c" }, + { } +}; +MODULE_DEVICE_TABLE(of, adc081c_of_match); +#endif + +static struct i2c_driver adc081c_driver = { + .driver = { + .name = "adc081c", + .owner = THIS_MODULE, + .of_match_table = of_match_ptr(adc081c_of_match), + }, + .probe = adc081c_probe, + .remove = adc081c_remove, + .id_table = adc081c_id, +}; +module_i2c_driver(adc081c_driver); + +MODULE_AUTHOR("Thierry Reding "); +MODULE_DESCRIPTION("Texas Instruments ADC081C021/027 driver"); +MODULE_LICENSE("GPL v2"); -- 2.7.4