iio: adc: new driver to support Linear technology's ltc2496 (e4c5c4df) · Commits · 戴 / test

MAINTAINERS

+1 −1

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		@@ -1045,7 +1045,7 @@ S: Supported
		F: Documentation/ABI/testing/sysfs-bus-iio-frequency-ad9523
		F: Documentation/ABI/testing/sysfs-bus-iio-frequency-adf4350
		F: drivers/iio//ad
		F: drivers/iio/adc/ltc2497*
		F: drivers/iio/adc/ltc249*
		X: drivers/iio//adjd
		F: drivers/staging/iio//ad

drivers/iio/adc/Kconfig

+10 −0

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		@@ -530,6 +530,16 @@ config LTC2485
		To compile this driver as a module, choose M here: the module will be
		called ltc2485.

		config LTC2496
		tristate "Linear Technology LTC2496 ADC driver"
		depends on SPI
		help
		Say yes here to build support for Linear Technology LTC2496
		16-Bit 8-/16-Channel Delta Sigma ADC.

		To compile this driver as a module, choose M here: the module will be
		called ltc2496.

		config LTC2497
		tristate "Linear Technology LTC2497 ADC driver"
		depends on I2C

drivers/iio/adc/Makefile

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		@@ -51,6 +51,7 @@ obj-$(CONFIG_LPC18XX_ADC) += lpc18xx_adc.o
		obj-$(CONFIG_LPC32XX_ADC) += lpc32xx_adc.o
		obj-$(CONFIG_LTC2471) += ltc2471.o
		obj-$(CONFIG_LTC2485) += ltc2485.o
		obj-$(CONFIG_LTC2496) += ltc2496.o ltc2497-core.o
		obj-$(CONFIG_LTC2497) += ltc2497.o ltc2497-core.o
		obj-$(CONFIG_MAX1027) += max1027.o
		obj-$(CONFIG_MAX11100) += max11100.o

drivers/iio/adc/ltc2496.c

0 → 100644

+108 −0

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		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* ltc2496.c - Driver for Analog Devices/Linear Technology LTC2496 ADC
		*
		* Based on ltc2497.c which has
		* Copyright (C) 2017 Analog Devices Inc.
		*
		* Licensed under the GPL-2.
		*
		* Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/2496fc.pdf
		*/

		#include <linux/spi/spi.h>
		#include <linux/iio/iio.h>
		#include <linux/iio/driver.h>
		#include <linux/module.h>
		#include <linux/of.h>

		#include "ltc2497.h"

		struct ltc2496_driverdata {
		/* this must be the first member */
		struct ltc2497core_driverdata common_ddata;
		struct spi_device *spi;

		/*
		* DMA (thus cache coherency maintenance) requires the
		* transfer buffers to live in their own cache lines.
		*/
		unsigned char rxbuf[3] ____cacheline_aligned;
		unsigned char txbuf[3];
		};

		static int ltc2496_result_and_measure(struct ltc2497core_driverdata *ddata,
		u8 address, int *val)
		{
		struct ltc2496_driverdata *st =
		container_of(ddata, struct ltc2496_driverdata, common_ddata);
		struct spi_transfer t = {
		.tx_buf = st->txbuf,
		.rx_buf = st->rxbuf,
		.len = sizeof(st->txbuf),
		};
		int ret;

		st->txbuf[0] = LTC2497_ENABLE \| address;

		ret = spi_sync_transfer(st->spi, &t, 1);
		if (ret < 0) {
		dev_err(&st->spi->dev, "spi_sync_transfer failed: %pe\n",
		ERR_PTR(ret));
		return ret;
		}

		if (val)
		*val = ((st->rxbuf[0] & 0x3f) << 12 \|
		st->rxbuf[1] << 4 \| st->rxbuf[2] >> 4) -
		(1 << 17);

		return 0;
		}

		static int ltc2496_probe(struct spi_device *spi)
		{
		struct iio_dev *indio_dev;
		struct ltc2496_driverdata *st;
		struct device *dev = &spi->dev;

		indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
		if (!indio_dev)
		return -ENOMEM;

		st = iio_priv(indio_dev);
		spi_set_drvdata(spi, indio_dev);
		st->spi = spi;
		st->common_ddata.result_and_measure = ltc2496_result_and_measure;

		return ltc2497core_probe(dev, indio_dev);
		}

		static int ltc2496_remove(struct spi_device *spi)
		{
		struct iio_dev *indio_dev = spi_get_drvdata(spi);

		ltc2497core_remove(indio_dev);

		return 0;
		}

		static const struct of_device_id ltc2496_of_match[] = {
		{ .compatible = "lltc,ltc2496", },
		{},
		};
		MODULE_DEVICE_TABLE(of, ltc2496_of_match);

		static struct spi_driver ltc2496_driver = {
		.driver = {
		.name = "ltc2496",
		.of_match_table = of_match_ptr(ltc2496_of_match),
		},
		.probe = ltc2496_probe,
		.remove = ltc2496_remove,
		};
		module_spi_driver(ltc2496_driver);

		MODULE_AUTHOR("Uwe Kleine-König <u.kleine-könig@pengutronix.de>");
		MODULE_DESCRIPTION("Linear Technology LTC2496 ADC driver");
		MODULE_LICENSE("GPL v2");

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