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Commit e717f8c6 authored by Dan Murphy's avatar Dan Murphy Committed by Jonathan Cameron
Browse files

iio: adc: Add the TI ads124s08 ADC code 

Introduce the TI ADS124S08 and the ADS124S06 ADC
devices from TI.  The ADS124S08 is the 12 channel ADC
and the ADS124S06 is the 6 channel ADC device

These devices share a common datasheet:
http://www.ti.com/lit/gpn/ads124s08



Signed-off-by: default avatarDan Murphy <dmurphy@ti.com>
Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 49ad8171

drivers/iio/adc/Kconfig

+10 −0
Original line number Diff line number Diff line
@@ -935,6 +935,16 @@ config TI_ADS8688 
	  This driver can also be built as a module. If so, the module will be

	  called ti-ads8688.



config TI_ADS124S08

	tristate "Texas Instruments ADS124S08"

	depends on SPI && OF

	help

	  If you say yes here you get support for Texas Instruments ADS124S08

	  and ADS124S06 ADC chips



	  This driver can also be built as a module. If so, the module will be

	  called ti-ads124s08.



config TI_AM335X_ADC

	tristate "TI's AM335X ADC driver"

	depends on MFD_TI_AM335X_TSCADC && HAS_DMA

drivers/iio/adc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -84,6 +84,7 @@ obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o 
obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o

obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o

obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o

obj-$(CONFIG_TI_ADS124S08) += ti-ads124s08.o

obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o

obj-$(CONFIG_TI_TLC4541) += ti-tlc4541.o

obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o

drivers/iio/adc/ti-ads124s08.c

0 → 100644
+376 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/* TI ADS124S0X chip family driver

 * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/

 */



#include <linux/err.h>

#include <linux/delay.h>

#include <linux/device.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/of.h>

#include <linux/of_gpio.h>

#include <linux/slab.h>

#include <linux/sysfs.h>



#include <linux/gpio/consumer.h>

#include <linux/spi/spi.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/iio/sysfs.h>



/* Commands */

#define ADS124S08_CMD_NOP	0x00

#define ADS124S08_CMD_WAKEUP	0x02

#define ADS124S08_CMD_PWRDWN	0x04

#define ADS124S08_CMD_RESET	0x06

#define ADS124S08_CMD_START	0x08

#define ADS124S08_CMD_STOP	0x0a

#define ADS124S08_CMD_SYOCAL	0x16

#define ADS124S08_CMD_SYGCAL	0x17

#define ADS124S08_CMD_SFOCAL	0x19

#define ADS124S08_CMD_RDATA	0x12

#define ADS124S08_CMD_RREG	0x20

#define ADS124S08_CMD_WREG	0x40



/* Registers */

#define ADS124S08_ID_REG	0x00

#define ADS124S08_STATUS	0x01

#define ADS124S08_INPUT_MUX	0x02

#define ADS124S08_PGA		0x03

#define ADS124S08_DATA_RATE	0x04

#define ADS124S08_REF		0x05

#define ADS124S08_IDACMAG	0x06

#define ADS124S08_IDACMUX	0x07

#define ADS124S08_VBIAS		0x08

#define ADS124S08_SYS		0x09

#define ADS124S08_OFCAL0	0x0a

#define ADS124S08_OFCAL1	0x0b

#define ADS124S08_OFCAL2	0x0c

#define ADS124S08_FSCAL0	0x0d

#define ADS124S08_FSCAL1	0x0e

#define ADS124S08_FSCAL2	0x0f

#define ADS124S08_GPIODAT	0x10

#define ADS124S08_GPIOCON	0x11



/* ADS124S0x common channels */

#define ADS124S08_AIN0		0x00

#define ADS124S08_AIN1		0x01

#define ADS124S08_AIN2		0x02

#define ADS124S08_AIN3		0x03

#define ADS124S08_AIN4		0x04

#define ADS124S08_AIN5		0x05

#define ADS124S08_AINCOM	0x0c

/* ADS124S08 only channels */

#define ADS124S08_AIN6		0x06

#define ADS124S08_AIN7		0x07

#define ADS124S08_AIN8		0x08

#define ADS124S08_AIN9		0x09

#define ADS124S08_AIN10		0x0a

#define ADS124S08_AIN11		0x0b

#define ADS124S08_MAX_CHANNELS	12



#define ADS124S08_POS_MUX_SHIFT	0x04

#define ADS124S08_INT_REF		0x09



#define ADS124S08_START_REG_MASK	0x1f

#define ADS124S08_NUM_BYTES_MASK	0x1f



#define ADS124S08_START_CONV	0x01

#define ADS124S08_STOP_CONV	0x00



enum ads124s_id {

	ADS124S08_ID,

	ADS124S06_ID,

};



struct ads124s_chip_info {

	const struct iio_chan_spec *channels;

	unsigned int num_channels;

};



struct ads124s_private {

	const struct ads124s_chip_info	*chip_info;

	struct gpio_desc *reset_gpio;

	struct spi_device *spi;

	struct mutex lock;

	u8 data[5] ____cacheline_aligned;

};



#define ADS124S08_CHAN(index)					\

{								\

	.type = IIO_VOLTAGE,					\

	.indexed = 1,						\

	.channel = index,					\

	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\

	.scan_index = index,					\

	.scan_type = {						\

		.sign = 'u',					\

		.realbits = 32,					\

		.storagebits = 32,				\

	},							\

}



static const struct iio_chan_spec ads124s06_channels[] = {

	ADS124S08_CHAN(0),

	ADS124S08_CHAN(1),

	ADS124S08_CHAN(2),

	ADS124S08_CHAN(3),

	ADS124S08_CHAN(4),

	ADS124S08_CHAN(5),

};



static const struct iio_chan_spec ads124s08_channels[] = {

	ADS124S08_CHAN(0),

	ADS124S08_CHAN(1),

	ADS124S08_CHAN(2),

	ADS124S08_CHAN(3),

	ADS124S08_CHAN(4),

	ADS124S08_CHAN(5),

	ADS124S08_CHAN(6),

	ADS124S08_CHAN(7),

	ADS124S08_CHAN(8),

	ADS124S08_CHAN(9),

	ADS124S08_CHAN(10),

	ADS124S08_CHAN(11),

};



static const struct ads124s_chip_info ads124s_chip_info_tbl[] = {

	[ADS124S08_ID] = {

		.channels = ads124s08_channels,

		.num_channels = ARRAY_SIZE(ads124s08_channels),

	},

	[ADS124S06_ID] = {

		.channels = ads124s06_channels,

		.num_channels = ARRAY_SIZE(ads124s06_channels),

	},

};



static int ads124s_write_cmd(struct iio_dev *indio_dev, u8 command)

{

	struct ads124s_private *priv = iio_priv(indio_dev);



	priv->data[0] = command;



	return spi_write(priv->spi, &priv->data[0], 1);

}



static int ads124s_write_reg(struct iio_dev *indio_dev, u8 reg, u8 data)

{

	struct ads124s_private *priv = iio_priv(indio_dev);



	priv->data[0] = ADS124S08_CMD_WREG | reg;

	priv->data[1] = 0x0;

	priv->data[2] = data;



	return spi_write(priv->spi, &priv->data[0], 3);

}



static int ads124s_reset(struct iio_dev *indio_dev)

{

	struct ads124s_private *priv = iio_priv(indio_dev);



	if (priv->reset_gpio) {

		gpiod_set_value(priv->reset_gpio, 0);

		udelay(200);

		gpiod_set_value(priv->reset_gpio, 1);

	} else {

		return ads124s_write_cmd(indio_dev, ADS124S08_CMD_RESET);

	}



	return 0;

};



static int ads124s_read(struct iio_dev *indio_dev, unsigned int chan)

{

	struct ads124s_private *priv = iio_priv(indio_dev);

	int ret;

	u32 tmp;

	struct spi_transfer t[] = {

		{

			.tx_buf = &priv->data[0],

			.len = 4,

			.cs_change = 1,

		}, {

			.tx_buf = &priv->data[1],

			.rx_buf = &priv->data[1],

			.len = 4,

		},

	};



	priv->data[0] = ADS124S08_CMD_RDATA;

	memset(&priv->data[1], ADS124S08_CMD_NOP, sizeof(priv->data));



	ret = spi_sync_transfer(priv->spi, t, ARRAY_SIZE(t));

	if (ret < 0)

		return ret;



	tmp = priv->data[2] << 16 | priv->data[3] << 8 | priv->data[4];



	return tmp;

}



static int ads124s_read_raw(struct iio_dev *indio_dev,

			    struct iio_chan_spec const *chan,

			    int *val, int *val2, long m)

{

	struct ads124s_private *priv = iio_priv(indio_dev);

	int ret;



	mutex_lock(&priv->lock);

	switch (m) {

	case IIO_CHAN_INFO_RAW:

		ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,

					chan->channel);

		if (ret) {

			dev_err(&priv->spi->dev, "Set ADC CH failed\n");

			goto out;

		}



		ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);

		if (ret) {

			dev_err(&priv->spi->dev, "Start converions failed\n");

			goto out;

		}



		ret = ads124s_read(indio_dev, chan->channel);

		if (ret < 0) {

			dev_err(&priv->spi->dev, "Read ADC failed\n");

			goto out;

		}



		*val = ret;



		ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);

		if (ret) {

			dev_err(&priv->spi->dev, "Stop converions failed\n");

			goto out;

		}



		ret = IIO_VAL_INT;

		break;

	default:

		ret = -EINVAL;

		break;

	}

out:

	mutex_unlock(&priv->lock);

	return ret;

}



static const struct iio_info ads124s_info = {

	.read_raw = &ads124s_read_raw,

};



static irqreturn_t ads124s_trigger_handler(int irq, void *p)

{

	struct iio_poll_func *pf = p;

	struct iio_dev *indio_dev = pf->indio_dev;

	struct ads124s_private *priv = iio_priv(indio_dev);

	u32 buffer[ADS124S08_MAX_CHANNELS + sizeof(s64)/sizeof(u16)];

	int scan_index, j = 0;

	int ret;



	for_each_set_bit(scan_index, indio_dev->active_scan_mask,

			 indio_dev->masklength) {

		ret = ads124s_write_reg(indio_dev, ADS124S08_INPUT_MUX,

					scan_index);

		if (ret)

			dev_err(&priv->spi->dev, "Set ADC CH failed\n");



		ret = ads124s_write_cmd(indio_dev, ADS124S08_START_CONV);

		if (ret)

			dev_err(&priv->spi->dev, "Start ADC converions failed\n");



		buffer[j] = ads124s_read(indio_dev, scan_index);

		ret = ads124s_write_cmd(indio_dev, ADS124S08_STOP_CONV);

		if (ret)

			dev_err(&priv->spi->dev, "Stop ADC converions failed\n");



		j++;

	}



	iio_push_to_buffers_with_timestamp(indio_dev, buffer,

			pf->timestamp);



	iio_trigger_notify_done(indio_dev->trig);



	return IRQ_HANDLED;

}



static int ads124s_probe(struct spi_device *spi)

{

	struct ads124s_private *ads124s_priv;

	struct iio_dev *indio_dev;

	const struct spi_device_id *spi_id = spi_get_device_id(spi);

	int ret;



	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ads124s_priv));

	if (indio_dev == NULL)

		return -ENOMEM;



	ads124s_priv = iio_priv(indio_dev);



	ads124s_priv->reset_gpio = devm_gpiod_get_optional(&spi->dev,

						   "reset", GPIOD_OUT_LOW);

	if (IS_ERR(ads124s_priv->reset_gpio))

		dev_info(&spi->dev, "Reset GPIO not defined\n");



	ads124s_priv->chip_info = &ads124s_chip_info_tbl[spi_id->driver_data];



	spi_set_drvdata(spi, indio_dev);



	ads124s_priv->spi = spi;



	indio_dev->name = spi_id->name;

	indio_dev->dev.parent = &spi->dev;

	indio_dev->dev.of_node = spi->dev.of_node;

	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->channels = ads124s_priv->chip_info->channels;

	indio_dev->num_channels = ads124s_priv->chip_info->num_channels;

	indio_dev->info = &ads124s_info;



	mutex_init(&ads124s_priv->lock);



	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,

					      ads124s_trigger_handler, NULL);

	if (ret) {

		dev_err(&spi->dev, "iio triggered buffer setup failed\n");

		return ret;

	}



	ads124s_reset(indio_dev);



	return devm_iio_device_register(&spi->dev, indio_dev);

}



static const struct spi_device_id ads124s_id[] = {

	{ "ads124s06", ADS124S06_ID },

	{ "ads124s08", ADS124S08_ID },

	{ }

};

MODULE_DEVICE_TABLE(spi, ads124s_id);



static const struct of_device_id ads124s_of_table[] = {

	{ .compatible = "ti,ads124s06" },

	{ .compatible = "ti,ads124s08" },

	{ },

};

MODULE_DEVICE_TABLE(of, ads124s_of_table);



static struct spi_driver ads124s_driver = {

	.driver = {

		.name	= "ads124s08",

		.of_match_table = ads124s_of_table,

	},

	.probe		= ads124s_probe,

	.id_table	= ads124s_id,

};

module_spi_driver(ads124s_driver);



MODULE_AUTHOR("Dan Murphy <dmuprhy@ti.com>");

MODULE_DESCRIPTION("TI TI_ADS12S0X ADC");

MODULE_LICENSE("GPL v2");