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From:   Stefan Popa <stefan.popa@analog.com>
To:     <jic23@kernel.org>, <Michael.Hennerich@analog.com>,
        <lars@metafoo.de>
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        <linux-iio@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <stefan.popa@analog.com>
Subject: [PATCH 1/2] iio:dac:ad5686: Add AD5691R/AD5692R/AD5693/AD5693R support
Date:   Fri, 18 May 2018 17:16:34 +0300
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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@analog.com>
---
 drivers/iio/dac/ad5686.c     | 88 +++++++++++++++++++++++++++++++++++++++++---
 drivers/iio/dac/ad5686.h     | 16 ++++++++
 drivers/iio/dac/ad5696-i2c.c |  7 +++-
 3 files changed, 104 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/dac/ad5686.c b/drivers/iio/dac/ad5686.c
index 89c5f08..be803e8 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 = 0;
+	u8 shift = 0;
 
 	ret = strtobool(buf, &readin);
 	if (ret)
@@ -80,9 +82,22 @@ 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;
+	}
 
+	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 +190,11 @@ 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 +220,112 @@ 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 +336,9 @@ 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 = 0;
+	u8 cmd = 0;
+	int ret, i, voltage_uv = 0;
 
 	indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
 	if (indio_dev == NULL)
@@ -310,7 +372,8 @@ 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 +382,21 @@ 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;
+	}
+
+	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