[PATCH v2 1/2] iio:dac:ad5686: Add AD5691R/AD5692R/AD5693/AD5693R support

From: Stefan Popa
Date: Fri May 18 2018 - 10:27:03 EST


The AD5691R/AD5692R/AD5693/AD5693R are a family of one channel DACs with
12-bit, 14-bit and 16-bit precision respectively. The devices have either
no built-in reference, or built-in 2.5V reference.

These devices are pretty similar to AD5671R/AD5675R and
AD5694/AD5694R/AD5695R/AD5696/AD5696R, except that they have one channel.
Another difference is that they use a write control register(addr 0x04) for
setting the power down modes and the internal reference instead of separate
registers for each function.

Datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/AD5693R_5692R_5691R_5693.pdf

Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx>
---
Changes in v2:
- Removed the initialization for ref_bit_msk and shift variables
from ad5686_write_dac_powerdown() and ad5686_probe().
- Added the the missing default case from
ad5686_write_dac_powerdown() and ad5686_probe().

drivers/iio/dac/ad5686.c | 93 +++++++++++++++++++++++++++++++++++++++++---
drivers/iio/dac/ad5686.h | 16 ++++++++
drivers/iio/dac/ad5696-i2c.c | 7 +++-
3 files changed, 109 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 89c5f08..1fc0c56 100644
--- a/drivers/iio/dac/ad5686.c
+++ b/drivers/iio/dac/ad5686.c
@@ -70,6 +70,8 @@ static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
bool readin;
int ret;
struct ad5686_state *st = iio_priv(indio_dev);
+ unsigned int val, ref_bit_msk;
+ u8 shift;

ret = strtobool(buf, &readin);
if (ret)
@@ -80,9 +82,24 @@ static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
else
st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));

- ret = st->write(st, AD5686_CMD_POWERDOWN_DAC, 0,
- st->pwr_down_mask & st->pwr_down_mode);
+ switch (st->chip_info->regmap_type) {
+ case AD5686_REGMAP:
+ shift = 0;
+ ref_bit_msk = 0;
+ break;
+ case AD5693_REGMAP:
+ shift = 13;
+ ref_bit_msk = AD5693_REF_BIT_MSK;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ val = ((st->pwr_down_mask & st->pwr_down_mode) << shift);
+ if (!st->use_internal_vref)
+ val |= ref_bit_msk;

+ ret = st->write(st, AD5686_CMD_POWERDOWN_DAC, 0, val);

return ret ? ret : len;
}
@@ -175,6 +192,11 @@ static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
.ext_info = ad5686_ext_info, \
}

+#define DECLARE_AD5693_CHANNELS(name, bits, _shift) \
+static struct iio_chan_spec name[] = { \
+ AD5868_CHANNEL(0, 0, bits, _shift), \
+}
+
#define DECLARE_AD5686_CHANNELS(name, bits, _shift) \
static struct iio_chan_spec name[] = { \
AD5868_CHANNEL(0, 1, bits, _shift), \
@@ -200,72 +222,112 @@ DECLARE_AD5676_CHANNELS(ad5676_channels, 16, 0);
DECLARE_AD5686_CHANNELS(ad5684_channels, 12, 4);
DECLARE_AD5686_CHANNELS(ad5685r_channels, 14, 2);
DECLARE_AD5686_CHANNELS(ad5686_channels, 16, 0);
+DECLARE_AD5693_CHANNELS(ad5693_channels, 16, 0);
+DECLARE_AD5693_CHANNELS(ad5692r_channels, 14, 2);
+DECLARE_AD5693_CHANNELS(ad5691r_channels, 12, 4);

static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
[ID_AD5671R] = {
.channels = ad5672_channels,
.int_vref_mv = 2500,
.num_channels = 8,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5672R] = {
.channels = ad5672_channels,
.int_vref_mv = 2500,
.num_channels = 8,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5675R] = {
.channels = ad5676_channels,
.int_vref_mv = 2500,
.num_channels = 8,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5676] = {
.channels = ad5676_channels,
.num_channels = 8,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5676R] = {
.channels = ad5676_channels,
.int_vref_mv = 2500,
.num_channels = 8,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5684] = {
.channels = ad5684_channels,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5684R] = {
.channels = ad5684_channels,
.int_vref_mv = 2500,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5685R] = {
.channels = ad5685r_channels,
.int_vref_mv = 2500,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5686] = {
.channels = ad5686_channels,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5686R] = {
.channels = ad5686_channels,
.int_vref_mv = 2500,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
+ },
+ [ID_AD5691R] = {
+ .channels = ad5691r_channels,
+ .int_vref_mv = 2500,
+ .num_channels = 1,
+ .regmap_type = AD5693_REGMAP,
+ },
+ [ID_AD5692R] = {
+ .channels = ad5692r_channels,
+ .int_vref_mv = 2500,
+ .num_channels = 1,
+ .regmap_type = AD5693_REGMAP,
+ },
+ [ID_AD5693] = {
+ .channels = ad5693_channels,
+ .num_channels = 1,
+ .regmap_type = AD5693_REGMAP,
+ },
+ [ID_AD5693R] = {
+ .channels = ad5693_channels,
+ .int_vref_mv = 2500,
+ .num_channels = 1,
+ .regmap_type = AD5693_REGMAP,
},
[ID_AD5694] = {
.channels = ad5684_channels,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5694R] = {
.channels = ad5684_channels,
.int_vref_mv = 2500,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5696] = {
.channels = ad5686_channels,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
[ID_AD5696R] = {
.channels = ad5686_channels,
.int_vref_mv = 2500,
.num_channels = 4,
+ .regmap_type = AD5686_REGMAP,
},
};

@@ -276,7 +338,9 @@ int ad5686_probe(struct device *dev,
{
struct ad5686_state *st;
struct iio_dev *indio_dev;
- int ret, voltage_uv = 0;
+ unsigned int val, ref_bit_msk;
+ u8 cmd;
+ int ret, i, voltage_uv = 0;

indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (indio_dev == NULL)
@@ -310,7 +374,8 @@ int ad5686_probe(struct device *dev,
st->vref_mv = st->chip_info->int_vref_mv;

/* Set all the power down mode for all channels to 1K pulldown */
- st->pwr_down_mode = 0x55;
+ for (i = 0; i < st->chip_info->num_channels; i++)
+ st->pwr_down_mode |= (0x01 << (i * 2));

indio_dev->dev.parent = dev;
indio_dev->name = name;
@@ -319,8 +384,24 @@ int ad5686_probe(struct device *dev,
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;

- ret = st->write(st, AD5686_CMD_INTERNAL_REFER_SETUP,
- 0, !!voltage_uv);
+ switch (st->chip_info->regmap_type) {
+ case AD5686_REGMAP:
+ cmd = AD5686_CMD_INTERNAL_REFER_SETUP;
+ ref_bit_msk = 0;
+ break;
+ case AD5693_REGMAP:
+ cmd = AD5686_CMD_CONTROL_REG;
+ ref_bit_msk = AD5693_REF_BIT_MSK;
+ st->use_internal_vref = !voltage_uv;
+ break;
+ default:
+ ret = -EINVAL;
+ goto error_disable_reg;
+ }
+
+ val = (voltage_uv | ref_bit_msk);
+
+ ret = st->write(st, cmd, 0, !!val);
if (ret)
goto error_disable_reg;

diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
index 05f0ce9..6c6879d 100644
--- a/drivers/iio/dac/ad5686.h
+++ b/drivers/iio/dac/ad5686.h
@@ -35,6 +35,9 @@
#define AD5686_LDAC_PWRDN_100K 0x2
#define AD5686_LDAC_PWRDN_3STATE 0x3

+#define AD5686_CMD_CONTROL_REG 0x4
+#define AD5693_REF_BIT_MSK BIT(12)
+
/**
* ad5686_supported_device_ids:
*/
@@ -49,6 +52,10 @@ enum ad5686_supported_device_ids {
ID_AD5685R,
ID_AD5686,
ID_AD5686R,
+ ID_AD5691R,
+ ID_AD5692R,
+ ID_AD5693,
+ ID_AD5693R,
ID_AD5694,
ID_AD5694R,
ID_AD5695R,
@@ -56,6 +63,11 @@ enum ad5686_supported_device_ids {
ID_AD5696R,
};

+enum ad5686_regmap_type {
+ AD5686_REGMAP,
+ AD5693_REGMAP
+};
+
struct ad5686_state;

typedef int (*ad5686_write_func)(struct ad5686_state *st,
@@ -68,12 +80,14 @@ typedef int (*ad5686_read_func)(struct ad5686_state *st, u8 addr);
* @int_vref_mv: AD5620/40/60: the internal reference voltage
* @num_channels: number of channels
* @channel: channel specification
+ * @regmap_type: register map layout variant
*/

struct ad5686_chip_info {
u16 int_vref_mv;
unsigned int num_channels;
struct iio_chan_spec *channels;
+ enum ad5686_regmap_type regmap_type;
};

/**
@@ -84,6 +98,7 @@ struct ad5686_chip_info {
* @vref_mv: actual reference voltage used
* @pwr_down_mask: power down mask
* @pwr_down_mode: current power down mode
+ * @use_internal_vref: set to true if the internal reference voltage is used
* @data: spi transfer buffers
*/

@@ -96,6 +111,7 @@ struct ad5686_state {
unsigned int pwr_down_mode;
ad5686_write_func write;
ad5686_read_func read;
+ bool use_internal_vref;

/*
* DMA (thus cache coherency maintenance) requires the
diff --git a/drivers/iio/dac/ad5696-i2c.c b/drivers/iio/dac/ad5696-i2c.c
index 275e032..d18735d 100644
--- a/drivers/iio/dac/ad5696-i2c.c
+++ b/drivers/iio/dac/ad5696-i2c.c
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0+
/*
- * AD5671R, AD5675R, AD5694, AD5694R, AD5695R, AD5696, AD5696R
+ * AD5671R, AD5675R, AD5691R, AD5692R, AD5693, AD5693R,
+ * AD5694, AD5694R, AD5695R, AD5696, AD5696R
* Digital to analog converters driver
*
* Copyright 2018 Analog Devices Inc.
@@ -72,6 +73,10 @@ static int ad5686_i2c_remove(struct i2c_client *i2c)
static const struct i2c_device_id ad5686_i2c_id[] = {
{"ad5671r", ID_AD5671R},
{"ad5675r", ID_AD5675R},
+ {"ad5691r", ID_AD5691R},
+ {"ad5692r", ID_AD5692R},
+ {"ad5693", ID_AD5693},
+ {"ad5693r", ID_AD5693R},
{"ad5694", ID_AD5694},
{"ad5694r", ID_AD5694R},
{"ad5695r", ID_AD5695R},
--
2.7.4