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Commit b12206e9 authored by Søren Andersen's avatar Søren Andersen Committed by Jonathan Cameron
Browse files

iio: adc: mcp320x. Add support for more ADCs 



Signed-off-by: Soeren Andersen <san at rosetechnology.dk>
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 064a7463

drivers/iio/adc/mcp320x.c

+187 −35
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2013 Oskar Andero <oskar.andero@gmail.com>

 * Copyright (C) 2014 Rose Technology

 * 	   Allan Bendorff Jensen <abj@rosetechnology.dk>

 *	   Soren Andersen <san@rosetechnology.dk>

 *

 * Driver for following ADC chips from Microchip Technology's:

 * 10 Bit converter

 * MCP3001

 * MCP3002

 * MCP3004

 * MCP3008

 * ------------

 * 12 bit converter

 * MCP3201

 * MCP3202

 * MCP3204

 * MCP3208

 * ------------

 *

 * Driver for Microchip Technology's MCP3204 and MCP3208 ADC chips.

 * Datasheet can be found here:

 * http://ww1.microchip.com/downloads/en/devicedoc/21298c.pdf

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf  mcp3002

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf  mcp3004/08

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf  mcp3201

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf  mcp3202

 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf  mcp3204/08

 *

 * 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
@@ -11,19 +32,29 @@ 
 */



#include <linux/err.h>

#include <linux/delay.h>

#include <linux/spi/spi.h>

#include <linux/module.h>

#include <linux/iio/iio.h>

#include <linux/regulator/consumer.h>



#define MCP_SINGLE_ENDED	(1 << 3)

#define MCP_START_BIT		(1 << 4)



enum {

	mcp3001,

	mcp3002,

	mcp3004,

	mcp3008,

	mcp3201,

	mcp3202,

	mcp3204,

	mcp3208,

};



struct mcp320x_chip_info {

	const struct iio_chan_spec *channels;

	unsigned int num_channels;

	unsigned int resolution;

};



struct mcp320x {

	struct spi_device *spi;

	struct spi_message msg;
@@ -34,19 +65,69 @@ struct mcp320x { 


	struct regulator *reg;

	struct mutex lock;

	const struct mcp320x_chip_info *chip_info;

};



static int mcp320x_adc_conversion(struct mcp320x *adc, u8 msg)

static int mcp320x_channel_to_tx_data(int device_index,

			const unsigned int channel, bool differential)

{

	int start_bit = 1;



	switch (device_index) {

	case mcp3001:

	case mcp3201:

		return 0;

	case mcp3002:

	case mcp3202:

		return ((start_bit << 4) | (!differential << 3) |

							(channel << 2));

	case mcp3004:

	case mcp3204:

	case mcp3008:

	case mcp3208:

		return ((start_bit << 6) | (!differential << 5) |

							(channel << 2));

	default:

		return -EINVAL;

	}

}



static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel,

				  bool differential, int device_index)

{

	int ret;



	adc->tx_buf = msg;

	adc->rx_buf[0] = 0;

	adc->rx_buf[1] = 0;

	adc->tx_buf = mcp320x_channel_to_tx_data(device_index,

						channel, differential);



	if (device_index != mcp3001 && device_index != mcp3201) {

		ret = spi_sync(adc->spi, &adc->msg);

		if (ret < 0)

			return ret;

	} else {

		ret = spi_read(adc->spi, &adc->rx_buf, sizeof(adc->rx_buf));

		if (ret < 0)

			return ret;

	}



	return ((adc->rx_buf[0] & 0x3f) << 6)  |

		(adc->rx_buf[1] >> 2);

	switch (device_index) {

	case mcp3001:

		return (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);

	case mcp3002:

	case mcp3004:

	case mcp3008:

		return (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);

	case mcp3201:

		return (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);

	case mcp3202:

	case mcp3204:

	case mcp3208:

		return (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);

	default:

		return -EINVAL;

	}

}



static int mcp320x_read_raw(struct iio_dev *indio_dev,
@@ -55,18 +136,17 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev, 
{

	struct mcp320x *adc = iio_priv(indio_dev);

	int ret = -EINVAL;

	int device_index = 0;



	mutex_lock(&adc->lock);



	device_index = spi_get_device_id(adc->spi)->driver_data;



	switch (mask) {

	case IIO_CHAN_INFO_RAW:

		if (channel->differential)

			ret = mcp320x_adc_conversion(adc,

				MCP_START_BIT | channel->address);

		else

			ret = mcp320x_adc_conversion(adc,

				MCP_START_BIT | MCP_SINGLE_ENDED |

				channel->address);

		ret = mcp320x_adc_conversion(adc, channel->address,

			channel->differential, device_index);



		if (ret < 0)

			goto out;
@@ -75,18 +155,15 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev, 
		break;



	case IIO_CHAN_INFO_SCALE:

		/* Digital output code = (4096 * Vin) / Vref */

		ret = regulator_get_voltage(adc->reg);

		if (ret < 0)

			goto out;



		/* convert regulator output voltage to mV */

		*val = ret / 1000;

		*val2 = 12;

		*val2 = adc->chip_info->resolution;

		ret = IIO_VAL_FRACTIONAL_LOG2;

		break;



	default:

		break;

	}



out:
@@ -117,6 +194,16 @@ static int mcp320x_read_raw(struct iio_dev *indio_dev, 
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \

	}



static const struct iio_chan_spec mcp3201_channels[] = {

	MCP320X_VOLTAGE_CHANNEL_DIFF(0),

};



static const struct iio_chan_spec mcp3202_channels[] = {

	MCP320X_VOLTAGE_CHANNEL(0),

	MCP320X_VOLTAGE_CHANNEL(1),

	MCP320X_VOLTAGE_CHANNEL_DIFF(0),

};



static const struct iio_chan_spec mcp3204_channels[] = {

	MCP320X_VOLTAGE_CHANNEL(0),

	MCP320X_VOLTAGE_CHANNEL(1),
@@ -146,19 +233,46 @@ static const struct iio_info mcp320x_info = { 
	.driver_module = THIS_MODULE,

};



struct mcp3208_chip_info {

	const struct iio_chan_spec *channels;

	unsigned int num_channels;

};



static const struct mcp3208_chip_info mcp3208_chip_infos[] = {

static const struct mcp320x_chip_info mcp320x_chip_infos[] = {

	[mcp3001] = {

		.channels = mcp3201_channels,

		.num_channels = ARRAY_SIZE(mcp3201_channels),

		.resolution = 10

	},

	[mcp3002] = {

		.channels = mcp3202_channels,

		.num_channels = ARRAY_SIZE(mcp3202_channels),

		.resolution = 10

	},

	[mcp3004] = {

		.channels = mcp3204_channels,

		.num_channels = ARRAY_SIZE(mcp3204_channels),

		.resolution = 10

	},

	[mcp3008] = {

		.channels = mcp3208_channels,

		.num_channels = ARRAY_SIZE(mcp3208_channels),

		.resolution = 10

	},

	[mcp3201] = {

		.channels = mcp3201_channels,

		.num_channels = ARRAY_SIZE(mcp3201_channels),

		.resolution = 12

	},

	[mcp3202] = {

		.channels = mcp3202_channels,

		.num_channels = ARRAY_SIZE(mcp3202_channels),

		.resolution = 12

	},

	[mcp3204] = {

		.channels = mcp3204_channels,

		.num_channels = ARRAY_SIZE(mcp3204_channels)

		.num_channels = ARRAY_SIZE(mcp3204_channels),

		.resolution = 12

	},

	[mcp3208] = {

		.channels = mcp3208_channels,

		.num_channels = ARRAY_SIZE(mcp3208_channels)

		.num_channels = ARRAY_SIZE(mcp3208_channels),

		.resolution = 12

	},

};
@@ -166,7 +280,7 @@ static int mcp320x_probe(struct spi_device *spi) 
{

	struct iio_dev *indio_dev;

	struct mcp320x *adc;

	const struct mcp3208_chip_info *chip_info;

	const struct mcp320x_chip_info *chip_info;

	int ret;



	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
@@ -181,7 +295,7 @@ static int mcp320x_probe(struct spi_device *spi) 
	indio_dev->modes = INDIO_DIRECT_MODE;

	indio_dev->info = &mcp320x_info;



	chip_info = &mcp3208_chip_infos[spi_get_device_id(spi)->driver_data];

	chip_info = &mcp320x_chip_infos[spi_get_device_id(spi)->driver_data];

	indio_dev->channels = chip_info->channels;

	indio_dev->num_channels = chip_info->num_channels;
@@ -226,7 +340,45 @@ static int mcp320x_remove(struct spi_device *spi) 
	return 0;

}



#if defined(CONFIG_OF)

static const struct of_device_id mcp320x_dt_ids[] = {

	{

		.compatible = "mcp3001",

		.data = &mcp320x_chip_infos[mcp3001],

	}, {

		.compatible = "mcp3002",

		.data = &mcp320x_chip_infos[mcp3002],

	}, {

		.compatible = "mcp3004",

		.data = &mcp320x_chip_infos[mcp3004],

	}, {

		.compatible = "mcp3008",

		.data = &mcp320x_chip_infos[mcp3008],

	}, {

		.compatible = "mcp3201",

		.data = &mcp320x_chip_infos[mcp3201],

	}, {

		.compatible = "mcp3202",

		.data = &mcp320x_chip_infos[mcp3202],

	}, {

		.compatible = "mcp3204",

		.data = &mcp320x_chip_infos[mcp3204],

	}, {

		.compatible = "mcp3208",

		.data = &mcp320x_chip_infos[mcp3208],

	}, {

	}

};

MODULE_DEVICE_TABLE(of, mcp320x_dt_ids);

#endif



static const struct spi_device_id mcp320x_id[] = {

	{ "mcp3001", mcp3001 },

	{ "mcp3002", mcp3002 },

	{ "mcp3004", mcp3004 },

	{ "mcp3008", mcp3008 },

	{ "mcp3201", mcp3201 },

	{ "mcp3202", mcp3202 },

	{ "mcp3204", mcp3204 },

	{ "mcp3208", mcp3208 },

	{ }
@@ -245,5 +397,5 @@ static struct spi_driver mcp320x_driver = { 
module_spi_driver(mcp320x_driver);



MODULE_AUTHOR("Oskar Andero <oskar.andero@gmail.com>");

MODULE_DESCRIPTION("Microchip Technology MCP3204/08");

MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08");

MODULE_LICENSE("GPL v2");