drivers/iio/adc/ti-adc108s102.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * TI ADC108S102 SPI ADC driver
  *
  * Copyright (c) 2013-2015 Intel Corporation.
  * Copyright (c) 2017 Siemens AG
  *
  * This IIO device driver is designed to work with the following
  * analog to digital converters from Texas Instruments:
  *  ADC108S102
  *  ADC128S102
  * The communication with ADC chip is via the SPI bus (mode 3).
  */

 #include <linux/acpi.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/types.h>
 #include <linux/iio/triggered_buffer.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/property.h>
 #include <linux/regulator/consumer.h>
 #include <linux/spi/spi.h>

 /*
  * In case of ACPI, we use the hard-wired 5000 mV of the Galileo and IOT2000
  * boards as default for the reference pin VA. Device tree users encode that
  * via the vref-supply regulator.
  */
 #define ADC108S102_VA_MV_ACPI_DEFAULT	5000

 /*
  * Defining the ADC resolution being 12 bits, we can use the same driver for
  * both ADC108S102 (10 bits resolution) and ADC128S102 (12 bits resolution)
  * chips. The ADC108S102 effectively returns a 12-bit result with the 2
  * least-significant bits unset.
  */
 #define ADC108S102_BITS		12
 #define ADC108S102_MAX_CHANNELS	8

 /*
  * 16-bit SPI command format:
  *   [15:14] Ignored
  *   [13:11] 3-bit channel address
  *   [10:0]  Ignored
  */
 #define ADC108S102_CMD(ch)		((u16)(ch) << 11)

 /*
  * 16-bit SPI response format:
  *   [15:12] Zeros
  *   [11:0]  12-bit ADC sample (for ADC108S102, [1:0] will always be 0).
  */
 #define ADC108S102_RES_DATA(res)	((u16)res & GENMASK(11, 0))

 struct adc108s102_state {
 	struct spi_device		*spi;
 	struct regulator		*reg;
 	u32				va_millivolt;
 	/* SPI transfer used by triggered buffer handler*/
 	struct spi_transfer		ring_xfer;
 	/* SPI transfer used by direct scan */
 	struct spi_transfer		scan_single_xfer;
 	/* SPI message used by ring_xfer SPI transfer */
 	struct spi_message		ring_msg;
 	/* SPI message used by scan_single_xfer SPI transfer */
 	struct spi_message		scan_single_msg;

 	/*
 	 * SPI message buffers:
 	 *  tx_buf: |C0|C1|C2|C3|C4|C5|C6|C7|XX|
 	 *  rx_buf: |XX|R0|R1|R2|R3|R4|R5|R6|R7|tt|tt|tt|tt|
 	 *
 	 *  tx_buf: 8 channel read commands, plus 1 dummy command
 	 *  rx_buf: 1 dummy response, 8 channel responses, plus 64-bit timestamp
 	 */
 	__be16				rx_buf[13] ____cacheline_aligned;
 	__be16				tx_buf[9] ____cacheline_aligned;
 };

 #define ADC108S102_V_CHAN(index)					\
 	{								\
 		.type = IIO_VOLTAGE,					\
 		.indexed = 1,						\
 		.channel = index,					\
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
 			BIT(IIO_CHAN_INFO_SCALE),			\
 		.address = index,					\
 		.scan_index = index,					\
 		.scan_type = {						\
 			.sign = 'u',					\
 			.realbits = ADC108S102_BITS,			\
 			.storagebits = 16,				\
 			.endianness = IIO_BE,				\
 		},							\
 	}

 static const struct iio_chan_spec adc108s102_channels[] = {
 	ADC108S102_V_CHAN(0),
 	ADC108S102_V_CHAN(1),
 	ADC108S102_V_CHAN(2),
 	ADC108S102_V_CHAN(3),
 	ADC108S102_V_CHAN(4),
 	ADC108S102_V_CHAN(5),
 	ADC108S102_V_CHAN(6),
 	ADC108S102_V_CHAN(7),
 	IIO_CHAN_SOFT_TIMESTAMP(8),
 };

 static int adc108s102_update_scan_mode(struct iio_dev *indio_dev,
 		unsigned long const *active_scan_mask)
 {
 	struct adc108s102_state *st = iio_priv(indio_dev);
 	unsigned int bit, cmds;

 	/*
 	 * Fill in the first x shorts of tx_buf with the number of channels
 	 * enabled for sampling by the triggered buffer.
 	 */
 	cmds = 0;
 	for_each_set_bit(bit, active_scan_mask, ADC108S102_MAX_CHANNELS)
 		st->tx_buf[cmds++] = cpu_to_be16(ADC108S102_CMD(bit));

 	/* One dummy command added, to clock in the last response */
 	st->tx_buf[cmds++] = 0x00;

 	/* build SPI ring message */
 	st->ring_xfer.tx_buf = &st->tx_buf[0];
 	st->ring_xfer.rx_buf = &st->rx_buf[0];
 	st->ring_xfer.len = cmds * sizeof(st->tx_buf[0]);

 	spi_message_init_with_transfers(&st->ring_msg, &st->ring_xfer, 1);

 	return 0;
 }

 static irqreturn_t adc108s102_trigger_handler(int irq, void *p)
 {
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct adc108s102_state *st = iio_priv(indio_dev);
 	int ret;

 	ret = spi_sync(st->spi, &st->ring_msg);
 	if (ret < 0)
 		goto out_notify;

 	/* Skip the dummy response in the first slot */
 	iio_push_to_buffers_with_timestamp(indio_dev,
 					   (u8 *)&st->rx_buf[1],
 					   iio_get_time_ns(indio_dev));

 out_notify:
 	iio_trigger_notify_done(indio_dev->trig);

 	return IRQ_HANDLED;
 }

 static int adc108s102_scan_direct(struct adc108s102_state *st, unsigned int ch)
 {
 	int ret;

 	st->tx_buf[0] = cpu_to_be16(ADC108S102_CMD(ch));
 	ret = spi_sync(st->spi, &st->scan_single_msg);
 	if (ret)
 		return ret;

 	/* Skip the dummy response in the first slot */
 	return be16_to_cpu(st->rx_buf[1]);
 }

 static int adc108s102_read_raw(struct iio_dev *indio_dev,
 			       struct iio_chan_spec const *chan,
 			       int *val, int *val2, long m)
 {
 	struct adc108s102_state *st = iio_priv(indio_dev);
 	int ret;

 	switch (m) {
 	case IIO_CHAN_INFO_RAW:
 		ret = iio_device_claim_direct_mode(indio_dev);
 		if (ret)
 			return ret;

 		ret = adc108s102_scan_direct(st, chan->address);

 		iio_device_release_direct_mode(indio_dev);

 		if (ret < 0)
 			return ret;

 		*val = ADC108S102_RES_DATA(ret);

 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_SCALE:
 		if (chan->type != IIO_VOLTAGE)
 			break;

 		*val = st->va_millivolt;
 		*val2 = chan->scan_type.realbits;

 		return IIO_VAL_FRACTIONAL_LOG2;
 	default:
 		break;
 	}

 	return -EINVAL;
 }

 static const struct iio_info adc108s102_info = {
 	.read_raw		= &adc108s102_read_raw,
 	.update_scan_mode	= &adc108s102_update_scan_mode,
 };

 static int adc108s102_probe(struct spi_device *spi)
 {
 	struct adc108s102_state *st;
 	struct iio_dev *indio_dev;
 	int ret;

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

 	st = iio_priv(indio_dev);

 	if (ACPI_COMPANION(&spi->dev)) {
 		st->va_millivolt = ADC108S102_VA_MV_ACPI_DEFAULT;
 	} else {
 		st->reg = devm_regulator_get(&spi->dev, "vref");
 		if (IS_ERR(st->reg))
 			return PTR_ERR(st->reg);

 		ret = regulator_enable(st->reg);
 		if (ret < 0) {
 			dev_err(&spi->dev, "Cannot enable vref regulator\n");
 			return ret;
 		}

 		ret = regulator_get_voltage(st->reg);
 		if (ret < 0) {
 			dev_err(&spi->dev, "vref get voltage failed\n");
 			return ret;
 		}

 		st->va_millivolt = ret / 1000;
 	}

 	spi_set_drvdata(spi, indio_dev);
 	st->spi = spi;

 	indio_dev->name = spi->modalias;
 	indio_dev->dev.parent = &spi->dev;
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = adc108s102_channels;
 	indio_dev->num_channels = ARRAY_SIZE(adc108s102_channels);
 	indio_dev->info = &adc108s102_info;

 	/* Setup default message */
 	st->scan_single_xfer.tx_buf = st->tx_buf;
 	st->scan_single_xfer.rx_buf = st->rx_buf;
 	st->scan_single_xfer.len = 2 * sizeof(st->tx_buf[0]);

 	spi_message_init_with_transfers(&st->scan_single_msg,
 					&st->scan_single_xfer, 1);

 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 &adc108s102_trigger_handler, NULL);
 	if (ret)
 		goto error_disable_reg;

 	ret = iio_device_register(indio_dev);
 	if (ret) {
 		dev_err(&spi->dev, "Failed to register IIO device\n");
 		goto error_cleanup_triggered_buffer;
 	}
 	return 0;

 error_cleanup_triggered_buffer:
 	iio_triggered_buffer_cleanup(indio_dev);

 error_disable_reg:
 	regulator_disable(st->reg);

 	return ret;
 }

 static int adc108s102_remove(struct spi_device *spi)
 {
 	struct iio_dev *indio_dev = spi_get_drvdata(spi);
 	struct adc108s102_state *st = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);
 	iio_triggered_buffer_cleanup(indio_dev);

 	regulator_disable(st->reg);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id adc108s102_of_match[] = {
 	{ .compatible = "ti,adc108s102" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, adc108s102_of_match);
 #endif

 #ifdef CONFIG_ACPI
 static const struct acpi_device_id adc108s102_acpi_ids[] = {
 	{ "INT3495", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(acpi, adc108s102_acpi_ids);
 #endif

 static const struct spi_device_id adc108s102_id[] = {
 	{ "adc108s102", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, adc108s102_id);

 static struct spi_driver adc108s102_driver = {
 	.driver = {
 		.name   = "adc108s102",
 		.of_match_table = of_match_ptr(adc108s102_of_match),
 		.acpi_match_table = ACPI_PTR(adc108s102_acpi_ids),
 	},
 	.probe		= adc108s102_probe,
 	.remove		= adc108s102_remove,
 	.id_table	= adc108s102_id,
 };
 module_spi_driver(adc108s102_driver);

 MODULE_AUTHOR("Bogdan Pricop <bogdan.pricop@emutex.com>");
 MODULE_DESCRIPTION("Texas Instruments ADC108S102 and ADC128S102 driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* TI ADC108S102 SPI ADC driver
	*
	* Copyright (c) 2013-2015 Intel Corporation.
	* Copyright (c) 2017 Siemens AG
	*
	* This IIO device driver is designed to work with the following
	* analog to digital converters from Texas Instruments:
	* ADC108S102
	* ADC128S102
	* The communication with ADC chip is via the SPI bus (mode 3).
	*/

	#include <linux/acpi.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/types.h>
	#include <linux/iio/triggered_buffer.h>
	#include <linux/iio/trigger_consumer.h>
	#include <linux/interrupt.h>
	#include <linux/module.h>
	#include <linux/property.h>
	#include <linux/regulator/consumer.h>
	#include <linux/spi/spi.h>

	/*
	* In case of ACPI, we use the hard-wired 5000 mV of the Galileo and IOT2000
	* boards as default for the reference pin VA. Device tree users encode that
	* via the vref-supply regulator.
	*/
	#define ADC108S102_VA_MV_ACPI_DEFAULT 5000

	/*
	* Defining the ADC resolution being 12 bits, we can use the same driver for
	* both ADC108S102 (10 bits resolution) and ADC128S102 (12 bits resolution)
	* chips. The ADC108S102 effectively returns a 12-bit result with the 2
	* least-significant bits unset.
	*/
	#define ADC108S102_BITS 12
	#define ADC108S102_MAX_CHANNELS 8

	/*
	* 16-bit SPI command format:
	* [15:14] Ignored
	* [13:11] 3-bit channel address
	* [10:0] Ignored
	*/
	#define ADC108S102_CMD(ch) ((u16)(ch) << 11)

	/*
	* 16-bit SPI response format:
	* [15:12] Zeros
	* [11:0] 12-bit ADC sample (for ADC108S102, [1:0] will always be 0).
	*/
	#define ADC108S102_RES_DATA(res) ((u16)res & GENMASK(11, 0))

	struct adc108s102_state {
	struct spi_device *spi;
	struct regulator *reg;
	u32 va_millivolt;
	/* SPI transfer used by triggered buffer handler*/
	struct spi_transfer ring_xfer;
	/* SPI transfer used by direct scan */
	struct spi_transfer scan_single_xfer;
	/* SPI message used by ring_xfer SPI transfer */
	struct spi_message ring_msg;
	/* SPI message used by scan_single_xfer SPI transfer */
	struct spi_message scan_single_msg;

	/*
	* SPI message buffers:
	* tx_buf: \|C0\|C1\|C2\|C3\|C4\|C5\|C6\|C7\|XX\|
	* rx_buf: \|XX\|R0\|R1\|R2\|R3\|R4\|R5\|R6\|R7\|tt\|tt\|tt\|tt\|
	*
	* tx_buf: 8 channel read commands, plus 1 dummy command
	* rx_buf: 1 dummy response, 8 channel responses, plus 64-bit timestamp
	*/
	__be16 rx_buf[13] ____cacheline_aligned;
	__be16 tx_buf[9] ____cacheline_aligned;
	};

	#define ADC108S102_V_CHAN(index) \
	{ \
	.type = IIO_VOLTAGE, \
	.indexed = 1, \
	.channel = index, \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \| \
	BIT(IIO_CHAN_INFO_SCALE), \
	.address = index, \
	.scan_index = index, \
	.scan_type = { \
	.sign = 'u', \
	.realbits = ADC108S102_BITS, \
	.storagebits = 16, \
	.endianness = IIO_BE, \
	}, \
	}

	static const struct iio_chan_spec adc108s102_channels[] = {
	ADC108S102_V_CHAN(0),
	ADC108S102_V_CHAN(1),
	ADC108S102_V_CHAN(2),
	ADC108S102_V_CHAN(3),
	ADC108S102_V_CHAN(4),
	ADC108S102_V_CHAN(5),
	ADC108S102_V_CHAN(6),
	ADC108S102_V_CHAN(7),
	IIO_CHAN_SOFT_TIMESTAMP(8),
	};

	static int adc108s102_update_scan_mode(struct iio_dev *indio_dev,
	unsigned long const *active_scan_mask)
	{
	struct adc108s102_state *st = iio_priv(indio_dev);
	unsigned int bit, cmds;

	/*
	* Fill in the first x shorts of tx_buf with the number of channels
	* enabled for sampling by the triggered buffer.
	*/
	cmds = 0;
	for_each_set_bit(bit, active_scan_mask, ADC108S102_MAX_CHANNELS)
	st->tx_buf[cmds++] = cpu_to_be16(ADC108S102_CMD(bit));

	/* One dummy command added, to clock in the last response */
	st->tx_buf[cmds++] = 0x00;

	/* build SPI ring message */
	st->ring_xfer.tx_buf = &st->tx_buf[0];
	st->ring_xfer.rx_buf = &st->rx_buf[0];
	st->ring_xfer.len = cmds * sizeof(st->tx_buf[0]);

	spi_message_init_with_transfers(&st->ring_msg, &st->ring_xfer, 1);

	return 0;
	}

	static irqreturn_t adc108s102_trigger_handler(int irq, void *p)
	{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct adc108s102_state *st = iio_priv(indio_dev);
	int ret;

	ret = spi_sync(st->spi, &st->ring_msg);
	if (ret < 0)
	goto out_notify;

	/* Skip the dummy response in the first slot */
	iio_push_to_buffers_with_timestamp(indio_dev,
	(u8 *)&st->rx_buf[1],
	iio_get_time_ns(indio_dev));

	out_notify:
	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
	}

	static int adc108s102_scan_direct(struct adc108s102_state *st, unsigned int ch)
	{
	int ret;

	st->tx_buf[0] = cpu_to_be16(ADC108S102_CMD(ch));
	ret = spi_sync(st->spi, &st->scan_single_msg);
	if (ret)
	return ret;

	/* Skip the dummy response in the first slot */
	return be16_to_cpu(st->rx_buf[1]);
	}

	static int adc108s102_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long m)
	{
	struct adc108s102_state *st = iio_priv(indio_dev);
	int ret;

	switch (m) {
	case IIO_CHAN_INFO_RAW:
	ret = iio_device_claim_direct_mode(indio_dev);
	if (ret)
	return ret;

	ret = adc108s102_scan_direct(st, chan->address);

	iio_device_release_direct_mode(indio_dev);

	if (ret < 0)
	return ret;

	*val = ADC108S102_RES_DATA(ret);

	return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
	if (chan->type != IIO_VOLTAGE)
	break;

	*val = st->va_millivolt;
	*val2 = chan->scan_type.realbits;

	return IIO_VAL_FRACTIONAL_LOG2;
	default:
	break;
	}

	return -EINVAL;
	}

	static const struct iio_info adc108s102_info = {
	.read_raw = &adc108s102_read_raw,
	.update_scan_mode = &adc108s102_update_scan_mode,
	};

	static int adc108s102_probe(struct spi_device *spi)
	{
	struct adc108s102_state *st;
	struct iio_dev *indio_dev;
	int ret;

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

	st = iio_priv(indio_dev);

	if (ACPI_COMPANION(&spi->dev)) {
	st->va_millivolt = ADC108S102_VA_MV_ACPI_DEFAULT;
	} else {
	st->reg = devm_regulator_get(&spi->dev, "vref");
	if (IS_ERR(st->reg))
	return PTR_ERR(st->reg);

	ret = regulator_enable(st->reg);
	if (ret < 0) {
	dev_err(&spi->dev, "Cannot enable vref regulator\n");
	return ret;
	}

	ret = regulator_get_voltage(st->reg);
	if (ret < 0) {
	dev_err(&spi->dev, "vref get voltage failed\n");
	return ret;
	}

	st->va_millivolt = ret / 1000;
	}

	spi_set_drvdata(spi, indio_dev);
	st->spi = spi;

	indio_dev->name = spi->modalias;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->modes = INDIO_DIRECT_MODE;
	indio_dev->channels = adc108s102_channels;
	indio_dev->num_channels = ARRAY_SIZE(adc108s102_channels);
	indio_dev->info = &adc108s102_info;

	/* Setup default message */
	st->scan_single_xfer.tx_buf = st->tx_buf;
	st->scan_single_xfer.rx_buf = st->rx_buf;
	st->scan_single_xfer.len = 2 * sizeof(st->tx_buf[0]);

	spi_message_init_with_transfers(&st->scan_single_msg,
	&st->scan_single_xfer, 1);

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
	&adc108s102_trigger_handler, NULL);
	if (ret)
	goto error_disable_reg;

	ret = iio_device_register(indio_dev);
	if (ret) {
	dev_err(&spi->dev, "Failed to register IIO device\n");
	goto error_cleanup_triggered_buffer;
	}
	return 0;

	error_cleanup_triggered_buffer:
	iio_triggered_buffer_cleanup(indio_dev);

	error_disable_reg:
	regulator_disable(st->reg);

	return ret;
	}

	static int adc108s102_remove(struct spi_device *spi)
	{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct adc108s102_state *st = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);

	regulator_disable(st->reg);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id adc108s102_of_match[] = {
	{ .compatible = "ti,adc108s102" },
	{ }
	};
	MODULE_DEVICE_TABLE(of, adc108s102_of_match);
	#endif

	#ifdef CONFIG_ACPI
	static const struct acpi_device_id adc108s102_acpi_ids[] = {
	{ "INT3495", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(acpi, adc108s102_acpi_ids);
	#endif

	static const struct spi_device_id adc108s102_id[] = {
	{ "adc108s102", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(spi, adc108s102_id);

	static struct spi_driver adc108s102_driver = {
	.driver = {
	.name = "adc108s102",
	.of_match_table = of_match_ptr(adc108s102_of_match),
	.acpi_match_table = ACPI_PTR(adc108s102_acpi_ids),
	},
	.probe = adc108s102_probe,
	.remove = adc108s102_remove,
	.id_table = adc108s102_id,
	};
	module_spi_driver(adc108s102_driver);

	MODULE_AUTHOR("Bogdan Pricop <bogdan.pricop@emutex.com>");
	MODULE_DESCRIPTION("Texas Instruments ADC108S102 and ADC128S102 driver");
	MODULE_LICENSE("GPL v2");