The AD7607, AD7608 and AD7609 are some older parts of the AD7606 family.
They are hardware-only, meaning that they don't have any registers
accessible via SPI or Parallel interface.
They are more similar to the AD7605-4 part, which is supported by the
'ad7606' driver, and are configurable via GPIOs.

Like the AD7605-4 part, all 3 parts have 2 CONVST (Conversion Start) pins
(CONVST A and CONVST B). But in practice, these should be tied together to
make reading of samples easier via a serial line.

The AD7607 has an 14-bit resolution and AD7608 & AD7609 have an 18-bit
resolution. The main difference between the AD7608 & AD7609 is that the
AD7609 has a larger range (±10V & ±20V) vs the ±5V & ±10V ranges for AD7608.

However, unlike AD7605-4 part, these 3 parts have oversampling which is
configurable (like for the AD7606 in HW-mode) via GPIOs.

Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7607.pdf
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7608.pdf
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7609.pdf

Signed-off-by: Alexandru Ardelean <aardelean@baylibre.com>
---
 drivers/iio/adc/ad7606.c     | 104 +++++++++++++++++++++++++++++++++++
 drivers/iio/adc/ad7606.h     |   3 +
 drivers/iio/adc/ad7606_par.c |   6 ++
 drivers/iio/adc/ad7606_spi.c |  42 ++++++++++++++
 4 files changed, 155 insertions(+)

diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
index 94756bb87b95..8b2046baaa3e 100644
--- a/drivers/iio/adc/ad7606.c
+++ b/drivers/iio/adc/ad7606.c
@@ -73,6 +73,14 @@ static const unsigned int ad7606_16bit_sw_scale_avail[3][2] = {
 	{ 0, 76293 }, { 0, 152588 }, { 0, 305176 }
 };
 
+static const unsigned int ad7607_hw_scale_avail[2][2] = {
+	{ 0, 610352 }, { 1, 220703 }
+};
+
+static const unsigned int ad7609_hw_scale_avail[2][2] = {
+	{ 0, 152588 }, { 0, 305176 }
+};
+
 static const unsigned int ad7606_oversampling_avail[7] = {
 	1, 2, 4, 8, 16, 32, 64,
 };
@@ -113,6 +121,30 @@ static const struct iio_chan_spec ad7606_channels_18bit[] = {
 	AD7606_CHANNEL(7, 18),
 };
 
+static const struct iio_chan_spec ad7607_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+	AD7606_CHANNEL(0, 14),
+	AD7606_CHANNEL(1, 14),
+	AD7606_CHANNEL(2, 14),
+	AD7606_CHANNEL(3, 14),
+	AD7606_CHANNEL(4, 14),
+	AD7606_CHANNEL(5, 14),
+	AD7606_CHANNEL(6, 14),
+	AD7606_CHANNEL(7, 14),
+};
+
+static const struct iio_chan_spec ad7608_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(8),
+	AD7606_CHANNEL(0, 18),
+	AD7606_CHANNEL(1, 18),
+	AD7606_CHANNEL(2, 18),
+	AD7606_CHANNEL(3, 18),
+	AD7606_CHANNEL(4, 18),
+	AD7606_CHANNEL(5, 18),
+	AD7606_CHANNEL(6, 18),
+	AD7606_CHANNEL(7, 18),
+};
+
 /*
  * The current assumption that this driver makes for AD7616, is that it's
  * working in Hardware Mode with Serial, Burst and Sequencer modes activated.
@@ -149,6 +181,12 @@ static int ad7606c_16bit_chan_scale_setup(struct ad7606_state *st,
 					  struct iio_chan_spec *chan, int ch);
 static int ad7606_16bit_chan_scale_setup(struct ad7606_state *st,
 					 struct iio_chan_spec *chan, int ch);
+static int ad7607_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch);
+static int ad7608_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch);
+static int ad7609_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch);
 
 const struct ad7606_chip_info ad7605_4_info = {
 	.channels = ad7605_channels,
@@ -215,6 +253,39 @@ const struct ad7606_chip_info ad7606c_16_info = {
 };
 EXPORT_SYMBOL_NS_GPL(ad7606c_16_info, IIO_AD7606);
 
+const struct ad7606_chip_info ad7607_info = {
+	.channels = ad7607_channels,
+	.name = "ad7607",
+	.num_adc_channels = 8,
+	.num_channels = 9,
+	.oversampling_avail = ad7606_oversampling_avail,
+	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
+	.scale_setup_cb = ad7607_chan_scale_setup,
+};
+EXPORT_SYMBOL_NS_GPL(ad7607_info, IIO_AD7606);
+
+const struct ad7606_chip_info ad7608_info = {
+	.channels = ad7608_channels,
+	.name = "ad7608",
+	.num_adc_channels = 8,
+	.num_channels = 9,
+	.oversampling_avail = ad7606_oversampling_avail,
+	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
+	.scale_setup_cb = ad7608_chan_scale_setup,
+};
+EXPORT_SYMBOL_NS_GPL(ad7608_info, IIO_AD7606);
+
+const struct ad7606_chip_info ad7609_info = {
+	.channels = ad7608_channels,
+	.name = "ad7609",
+	.num_adc_channels = 8,
+	.num_channels = 9,
+	.oversampling_avail = ad7606_oversampling_avail,
+	.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
+	.scale_setup_cb = ad7609_chan_scale_setup,
+};
+EXPORT_SYMBOL_NS_GPL(ad7609_info, IIO_AD7606);
+
 const struct ad7606_chip_info ad7606c_18_info = {
 	.channels = ad7606_channels_18bit,
 	.name = "ad7606c18",
@@ -441,6 +512,39 @@ static int ad7606c_16bit_chan_scale_setup(struct ad7606_state *st,
 	return 0;
 }
 
+static int ad7607_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch)
+{
+	struct ad7606_chan_scale *cs = &st->chan_scales[ch];
+
+	cs->range = 0;
+	cs->scale_avail = ad7607_hw_scale_avail;
+	cs->num_scales = ARRAY_SIZE(ad7607_hw_scale_avail);
+	return 0;
+}
+
+static int ad7608_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch)
+{
+	struct ad7606_chan_scale *cs = &st->chan_scales[ch];
+
+	cs->range = 0;
+	cs->scale_avail = ad7606_18bit_hw_scale_avail;
+	cs->num_scales = ARRAY_SIZE(ad7606_18bit_hw_scale_avail);
+	return 0;
+}
+
+static int ad7609_chan_scale_setup(struct ad7606_state *st,
+				   struct iio_chan_spec *chan, int ch)
+{
+	struct ad7606_chan_scale *cs = &st->chan_scales[ch];
+
+	cs->range = 0;
+	cs->scale_avail = ad7609_hw_scale_avail;
+	cs->num_scales = ARRAY_SIZE(ad7609_hw_scale_avail);
+	return 0;
+}
+
 static int ad7606_reg_access(struct iio_dev *indio_dev,
 			     unsigned int reg,
 			     unsigned int writeval,
diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
index 32c6f776c5df..998814a92b82 100644
--- a/drivers/iio/adc/ad7606.h
+++ b/drivers/iio/adc/ad7606.h
@@ -237,6 +237,9 @@ extern const struct ad7606_chip_info ad7606_4_info;
 extern const struct ad7606_chip_info ad7606b_info;
 extern const struct ad7606_chip_info ad7606c_16_info;
 extern const struct ad7606_chip_info ad7606c_18_info;
+extern const struct ad7606_chip_info ad7607_info;
+extern const struct ad7606_chip_info ad7608_info;
+extern const struct ad7606_chip_info ad7609_info;
 extern const struct ad7606_chip_info ad7616_info;
 
 #ifdef CONFIG_PM_SLEEP
diff --git a/drivers/iio/adc/ad7606_par.c b/drivers/iio/adc/ad7606_par.c
index 4e729777d373..a25182a3daa7 100644
--- a/drivers/iio/adc/ad7606_par.c
+++ b/drivers/iio/adc/ad7606_par.c
@@ -211,6 +211,9 @@ static const struct platform_device_id ad7606_driver_ids[] = {
 	{ .name	= "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
 	{ .name	= "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
 	{ .name	= "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
+	{ .name	= "ad7607", .driver_data = (kernel_ulong_t)&ad7607_info, },
+	{ .name	= "ad7608", .driver_data = (kernel_ulong_t)&ad7608_info, },
+	{ .name	= "ad7609", .driver_data = (kernel_ulong_t)&ad7609_info, },
 	{ }
 };
 MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
@@ -221,6 +224,9 @@ static const struct of_device_id ad7606_of_match[] = {
 	{ .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
 	{ .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
 	{ .compatible = "adi,ad7606b", .data = &ad7606b_info },
+	{ .compatible = "adi,ad7607", .data = &ad7607_info },
+	{ .compatible = "adi,ad7608", .data = &ad7608_info },
+	{ .compatible = "adi,ad7609", .data = &ad7609_info },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, ad7606_of_match);
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c
index 44c6031e9e9a..0662300cde8d 100644
--- a/drivers/iio/adc/ad7606_spi.c
+++ b/drivers/iio/adc/ad7606_spi.c
@@ -132,6 +132,19 @@ static int ad7606_spi_read_block(struct device *dev,
 	return 0;
 }
 
+static int ad7606_spi_read_block14to16(struct device *dev,
+				       int count, void *buf)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	struct spi_transfer xfer = {
+		.bits_per_word = 14,
+		.len = count * sizeof(u16),
+		.rx_buf = buf,
+	};
+
+	return spi_sync_transfer(spi, &xfer, 1);
+}
+
 static int ad7606_spi_read_block18to32(struct device *dev,
 				       int count, void *buf)
 {
@@ -325,6 +338,14 @@ static const struct ad7606_bus_ops ad7606_spi_bops = {
 	.read_block = ad7606_spi_read_block,
 };
 
+static const struct ad7606_bus_ops ad7607_spi_bops = {
+	.read_block = ad7606_spi_read_block14to16,
+};
+
+static const struct ad7606_bus_ops ad7608_spi_bops = {
+	.read_block = ad7606_spi_read_block18to32,
+};
+
 static const struct ad7606_bus_ops ad7616_spi_bops = {
 	.read_block = ad7606_spi_read_block,
 	.reg_read = ad7606_spi_reg_read,
@@ -387,6 +408,21 @@ static const struct ad7606_bus_info ad7606c_18_bus_info = {
 	.bops = &ad7606c_18_spi_bops,
 };
 
+static const struct ad7606_bus_info ad7607_bus_info = {
+	.chip_info = &ad7607_info,
+	.bops = &ad7607_spi_bops,
+};
+
+static const struct ad7606_bus_info ad7608_bus_info = {
+	.chip_info = &ad7608_info,
+	.bops = &ad7608_spi_bops,
+};
+
+static const struct ad7606_bus_info ad7609_bus_info = {
+	.chip_info = &ad7609_info,
+	.bops = &ad7608_spi_bops,
+};
+
 static const struct ad7606_bus_info ad7616_bus_info = {
 	.chip_info = &ad7616_info,
 	.bops = &ad7616_spi_bops,
@@ -408,6 +444,9 @@ static const struct spi_device_id ad7606_id_table[] = {
 	{ "ad7606b",  (kernel_ulong_t)&ad7606b_bus_info },
 	{ "ad7606c-16", (kernel_ulong_t)&ad7606c_16_bus_info },
 	{ "ad7606c-18", (kernel_ulong_t)&ad7606c_18_bus_info },
+	{ "ad7607",   (kernel_ulong_t)&ad7607_bus_info },
+	{ "ad7608",   (kernel_ulong_t)&ad7608_bus_info },
+	{ "ad7609",   (kernel_ulong_t)&ad7609_bus_info },
 	{ "ad7616",   (kernel_ulong_t)&ad7616_bus_info },
 	{ }
 };
@@ -421,6 +460,9 @@ static const struct of_device_id ad7606_of_match[] = {
 	{ .compatible = "adi,ad7606b", .data = &ad7606b_bus_info },
 	{ .compatible = "adi,ad7606c-16", .data = &ad7606c_16_bus_info },
 	{ .compatible = "adi,ad7606c-18", .data = &ad7606c_18_bus_info },
+	{ .compatible = "adi,ad7607", .data = &ad7607_bus_info },
+	{ .compatible = "adi,ad7608", .data = &ad7608_bus_info },
+	{ .compatible = "adi,ad7609", .data = &ad7609_bus_info },
 	{ .compatible = "adi,ad7616", .data = &ad7616_bus_info },
 	{ }
 };
-- 
2.46.1