Add generic driver to support sigma delta modulators.
Signed-off-by: Arnaud Pouliquen arnaud.pouliquen@st.com --- V2 -> V3 : -Rename to suppress "simple" - add "ads1201" compatibility
drivers/iio/adc/Kconfig | 11 +++++ drivers/iio/adc/Makefile | 1 + drivers/iio/adc/sd_adc_modulator.c | 98 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 110 insertions(+) create mode 100644 drivers/iio/adc/sd_adc_modulator.c
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig index e0b3c09..d411d66 100644 --- a/drivers/iio/adc/Kconfig +++ b/drivers/iio/adc/Kconfig @@ -419,6 +419,17 @@ config ROCKCHIP_SARADC To compile this driver as a module, choose M here: the module will be called rockchip_saradc.
+config SD_ADC_MODULATOR + tristate "Basic sigma delta modulator" + depends on OF + select IIO_BUFFER + select IIO_TRIGGERED_BUFFER + help + Select this option to enables generic sigma delta modulator. + + This driver can also be built as a module. If so, the module + will be called simple-sd-adc. + config STM32_ADC_CORE tristate "STMicroelectronics STM32 adc core" depends on ARCH_STM32 || COMPILE_TEST diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile index 8e02a94..c68819c 100644 --- a/drivers/iio/adc/Makefile +++ b/drivers/iio/adc/Makefile @@ -57,3 +57,4 @@ obj-$(CONFIG_VF610_ADC) += vf610_adc.o obj-$(CONFIG_VIPERBOARD_ADC) += viperboard_adc.o xilinx-xadc-y := xilinx-xadc-core.o xilinx-xadc-events.o obj-$(CONFIG_XILINX_XADC) += xilinx-xadc.o +obj-$(CONFIG_SD_ADC_MODULATOR) += sd_adc_modulator.o diff --git a/drivers/iio/adc/sd_adc_modulator.c b/drivers/iio/adc/sd_adc_modulator.c new file mode 100644 index 0000000..4a25642 --- /dev/null +++ b/drivers/iio/adc/sd_adc_modulator.c @@ -0,0 +1,98 @@ +/* + * Basic sigma delta modulator driver + * + * Copyright (C) 2016, STMicroelectronics - All Rights Reserved + * Author: Arnaud Pouliquen arnaud.pouliquen@st.com. + * + * License type: GPLv2 + * + * 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. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY + * or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along with + * this program. If not, see http://www.gnu.org/licenses/. + */ + +#include <linux/iio/iio.h> +#include <linux/module.h> +#include <linux/of_device.h> + +#include <linux/iio/triggered_buffer.h> + +static int iio_sd_mod_of_xlate(struct iio_dev *iio, + const struct of_phandle_args *iiospec) +{ + dev_dbg(&iio->dev, "%s:\n", __func__); + if (iiospec->args[0] != 0) { + dev_err(&iio->dev, "Only one channel supported\n"); + return -EINVAL; + } + + return 0; +} + +static const struct iio_info iio_sd_mod_iio_info = { + .of_xlate = iio_sd_mod_of_xlate, +}; + +static const struct iio_chan_spec stm32_dfsdm_ch = { + .type = IIO_VOLTAGE, + .indexed = 1, + .scan_index = 0, + .scan_type = { + .sign = 'u', + .realbits = 1, + .shift = 0, + }, +}; + +static int iio_sd_mod_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct iio_dev *iio; + + dev_dbg(&pdev->dev, "%s:\n", __func__); + iio = devm_iio_device_alloc(dev, 0); + if (!iio) + return -ENOMEM; + + iio->dev.parent = dev; + iio->dev.of_node = dev->of_node; + iio->name = dev_name(dev); + iio->info = &iio_sd_mod_iio_info; + iio->modes = INDIO_BUFFER_HARDWARE; + + iio->num_channels = 1; + iio->channels = &stm32_dfsdm_ch; + + platform_set_drvdata(pdev, iio); + + return devm_iio_device_register(&pdev->dev, iio); +} + +static const struct of_device_id sd_adc_of_match[] = { + { .compatible = "sd-modulator" }, + { .compatible = "ads1201" }, + { } +}; +MODULE_DEVICE_TABLE(of, adc081c_of_match); + +static struct platform_driver iio_sd_mod_adc = { + .driver = { + .name = "iio_sd_adc_mod", + .of_match_table = of_match_ptr(sd_adc_of_match), + }, + .probe = iio_sd_mod_probe, +}; + +module_platform_driver(iio_sd_mod_adc); + +MODULE_DESCRIPTION("Basic sigma delta modulator"); +MODULE_AUTHOR("Arnaud Pouliquen arnaud.pouliquen@st.com"); +MODULE_LICENSE("GPL v2");