Commit 35f73967 authored by Akinobu Mita's avatar Akinobu Mita Committed by Jonathan Cameron
Browse files

iio: dac: mcp4725: Add basic support for MCP4726 

MCP4726 is a single channel 12-bit DAC.  We can support MCP4726 with
a little changes to mcp4725 driver.  In power-down mode, they have
different selection of VOUT pull-down registers.

MCP4726 also has features:
 - Output gain options: 1x, 2x
 - Voltage reference selection: VDD, VREF (Unbuffered or Buffered)

But these are not supported in this change. (1x gain, VDD is selected)

datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/22272C.pdf



Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Hartmut Knaack <knaack.h@gmx.de>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Peter Meerwald <pmeerw@pmeerw.net>
Cc: linux-iio@vger.kernel.org
Signed-off-by: default avatarJonathan Cameron <jic23@kernel.org>
parent 505abf99

Documentation/ABI/testing/sysfs-bus-iio

+2 −0
Original line number Diff line number Diff line
@@ -497,7 +497,9 @@ Description: 
		6kohm_to_gnd: connected to ground via a 6kOhm resistor,

		20kohm_to_gnd: connected to ground via a 20kOhm resistor,

		100kohm_to_gnd: connected to ground via an 100kOhm resistor,

		125kohm_to_gnd: connected to ground via an 125kOhm resistor,

		500kohm_to_gnd: connected to ground via a 500kOhm resistor,

		640kohm_to_gnd: connected to ground via a 640kOhm resistor,

		three_state: left floating.

		For a list of available output power down options read

		outX_powerdown_mode_available. If Y is not present the

drivers/iio/dac/Kconfig

+2 −2
Original line number Diff line number Diff line
@@ -176,11 +176,11 @@ config MAX5821 
	  10 bits DAC.



config MCP4725

	tristate "MCP4725 DAC driver"

	tristate "MCP4725/6 DAC driver"

	depends on I2C

	---help---

	  Say Y here if you want to build a driver for the Microchip

	  MCP 4725 12-bit digital-to-analog converter (DAC) with I2C

	  MCP 4725/6 12-bit digital-to-analog converter (DAC) with I2C

	  interface.



	  To compile this driver as a module, choose M here: the module

drivers/iio/dac/mcp4725.c

+67 −20
Original line number Diff line number Diff line 
/*

 * mcp4725.c - Support for Microchip MCP4725

 * mcp4725.c - Support for Microchip MCP4725/6

 *

 * Copyright (C) 2012 Peter Meerwald <pmeerw@pmeerw.net>

 *
@@ -134,6 +134,12 @@ static const char * const mcp4725_powerdown_modes[] = { 
	"500kohm_to_gnd"

};



static const char * const mcp4726_powerdown_modes[] = {

	"1kohm_to_gnd",

	"125kohm_to_gnd",

	"640kohm_to_gnd"

};



static int mcp4725_get_powerdown_mode(struct iio_dev *indio_dev,

	const struct iio_chan_spec *chan)

{
@@ -182,11 +188,24 @@ static ssize_t mcp4725_write_powerdown(struct iio_dev *indio_dev, 
	return len;

}



static const struct iio_enum mcp4725_powerdown_mode_enum = {

enum {

	MCP4725,

	MCP4726,

};



static const struct iio_enum mcp472x_powerdown_mode_enum[] = {

	[MCP4725] = {

		.items = mcp4725_powerdown_modes,

		.num_items = ARRAY_SIZE(mcp4725_powerdown_modes),

		.get = mcp4725_get_powerdown_mode,

		.set = mcp4725_set_powerdown_mode,

	},

	[MCP4726] = {

		.items = mcp4726_powerdown_modes,

		.num_items = ARRAY_SIZE(mcp4726_powerdown_modes),

		.get = mcp4725_get_powerdown_mode,

		.set = mcp4725_set_powerdown_mode,

	},

};



static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = {
@@ -196,12 +215,29 @@ static const struct iio_chan_spec_ext_info mcp4725_ext_info[] = { 
		.write = mcp4725_write_powerdown,

		.shared = IIO_SEPARATE,

	},

	IIO_ENUM("powerdown_mode", IIO_SEPARATE, &mcp4725_powerdown_mode_enum),

	IIO_ENUM_AVAILABLE("powerdown_mode", &mcp4725_powerdown_mode_enum),

	IIO_ENUM("powerdown_mode", IIO_SEPARATE,

			&mcp472x_powerdown_mode_enum[MCP4725]),

	IIO_ENUM_AVAILABLE("powerdown_mode",

			&mcp472x_powerdown_mode_enum[MCP4725]),

	{ },

};



static const struct iio_chan_spec_ext_info mcp4726_ext_info[] = {

	{

		.name = "powerdown",

		.read = mcp4725_read_powerdown,

		.write = mcp4725_write_powerdown,

		.shared = IIO_SEPARATE,

	},

	IIO_ENUM("powerdown_mode", IIO_SEPARATE,

			&mcp472x_powerdown_mode_enum[MCP4726]),

	IIO_ENUM_AVAILABLE("powerdown_mode",

			&mcp472x_powerdown_mode_enum[MCP4726]),

	{ },

};



static const struct iio_chan_spec mcp4725_channel = {

static const struct iio_chan_spec mcp472x_channel[] = {

	[MCP4725] = {

		.type		= IIO_VOLTAGE,

		.indexed	= 1,

		.output		= 1,
@@ -209,6 +245,16 @@ static const struct iio_chan_spec mcp4725_channel = { 
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),

		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),

		.ext_info	= mcp4725_ext_info,

	},

	[MCP4726] = {

		.type		= IIO_VOLTAGE,

		.indexed	= 1,

		.output		= 1,

		.channel	= 0,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),

		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),

		.ext_info	= mcp4726_ext_info,

	},

};



static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
@@ -301,7 +347,7 @@ static int mcp4725_probe(struct i2c_client *client, 


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

	indio_dev->info = &mcp4725_info;

	indio_dev->channels = &mcp4725_channel;

	indio_dev->channels = &mcp472x_channel[id->driver_data];

	indio_dev->num_channels = 1;

	indio_dev->modes = INDIO_DIRECT_MODE;
@@ -315,7 +361,7 @@ static int mcp4725_probe(struct i2c_client *client, 
	}

	pd = (inbuf[0] >> 1) & 0x3;

	data->powerdown = pd > 0 ? true : false;

	data->powerdown_mode = pd ? pd-1 : 2; /* 500kohm_to_gnd */

	data->powerdown_mode = pd ? pd - 1 : 2; /* largest register to gnd */

	data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);



	return iio_device_register(indio_dev);
@@ -328,7 +374,8 @@ static int mcp4725_remove(struct i2c_client *client) 
}



static const struct i2c_device_id mcp4725_id[] = {

	{ "mcp4725", 0 },

	{ "mcp4725", MCP4725 },

	{ "mcp4726", MCP4726 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, mcp4725_id);
@@ -345,5 +392,5 @@ static struct i2c_driver mcp4725_driver = { 
module_i2c_driver(mcp4725_driver);



MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");

MODULE_DESCRIPTION("MCP4725 12-bit DAC");

MODULE_DESCRIPTION("MCP4725/6 12-bit DAC");

MODULE_LICENSE("GPL");

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