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: Akinobu 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: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index 0439c2aaf7419867c1dce0c223190530eb970d70..8fadd272ad8ae152f52817e245d1c924c86340aa 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -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

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index e701e28fb1cd6009212bae9a19c4ac81ae8cb90f..5263c5125fbbfeb569ff461d6f84141c0fa4d7e3 100644 (file)
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -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

diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index 43d14588448d65f507ab02ce22c0e01d7a9008ad..fb4b3364d8e09da93e945905c9bd4ff5e723f980 100644 (file)
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -1,5 +1,5 @@
 /*
- * 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 = {
-       .items = mcp4725_powerdown_modes,
-       .num_items = ARRAY_SIZE(mcp4725_powerdown_modes),
-       .get = mcp4725_get_powerdown_mode,
-       .set = mcp4725_set_powerdown_mode,
+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[] = {
@@ -196,19 +215,46 @@ 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 = {
-       .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       = mcp4725_ext_info,
+static const struct iio_chan_spec mcp472x_channel[] = {
+       [MCP4725] = {
+               .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       = 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");