[PATCH v7 0/7] iio: adc: add new ad7380 driver

[PATCH v7 0/7] iio: adc: add new ad7380 driver

[Julien Stephan]

Taking over this series with David Lechner's approval, to add some
fixes, proper handling of pseudo differential parts and
some extra commits to add support for 4-channel compatible parts.

Here is David's cover letter:

This series is adding a new driver for the Analog Devices Inc. AD7380,
AD7381, AD7383, and AD7384 ADCs. These chips are part of a family of
simultaneous sampling SAR ADCs.

To keep things simple, the initial driver implementation only supports
the 2/4-channel differential chips listed above. There are also 4-channel
single-ended chips in the family that can be added later.

Furthermore, the driver is just implementing basic support for capturing
data. Additional features like interrupts, CRC, etc. can be added later.

This work is being done by BayLibre and on behalf of Analog Devices Inc.
hence the maintainers are @analog.com.

Changes in v7:
- Removing oversampling support and resolution boost from this series. 
  They will be submitted along with David's series about multiple scan
  types [1], thus removing the RFC tag.

 [1]: https://lore.kernel.org/all/20240524-iio-add-support-for-multiple-scan-types-v2-0-a6c328fdfab7@baylibre.com/

- Link to v6: https://lore.kernel.org/r/20240501-adding-new-ad738x-driver-v6-0-3c0741154728@baylibre.com

Changes in v6:
- Added a comment for math in IIO_CHAN_INFO_OFFSET
- Added a comment for raw buffer
- use iio_device_claim_direct_scoped instead of iio_device_claim_direct_mode

Adding the following commits on top of v5:
- add oversampling support
- add resolution boost support

- Link to v5: https://lore.kernel.org/r/20240319-adding-new-ad738x-driver-v5-0-ce7df004ceb3@baylibre.com

Changes in v5:
- make ad7380_regmap_config static
  Reported-by: kernel test robot <lkp@intel.com>
  Closes: https://lore.kernel.org/oe-kbuild-all/202401280629.5kknB57C-lkp@intel.com/
- don't use bool in FIELD_PREP
  Reported-by: kernel test robot <lkp@intel.com>
  Closes: https://lore.kernel.org/oe-kbuild-all/202401280629.5kknB57C-lkp@intel.com/
- fix rx/tx buffer for regmap access
- add datasheet links of supported parts
- move reading reference voltage to probe function
- removed DIFFERENTIAL from a few macro names

Adding the following commits on top of the v4
- add supplies for pseudo-differential chips
- prepare driver to add more compatible parts
- add support for 4-channel compatible parts

- Link to v4: https://lore.kernel.org/all/20240110-ad7380-mainline-v4-0-93a1d96b50fa@baylibre.com

Changes in v4:
- Dropped SPI bindings patch.
- Removed `spi-rx-bus-channels` from the adi,ad7380 bindings.
- Link to v3: https://lore.kernel.org/r/20231215-ad7380-mainline-v3-0-7a11ebf642b9@baylibre.com

Changes in v3:
- dt-bindings:
    - Picked up Conor's Reviewed-By on the adi,ad7380 bindings
- driver:
    - Removed extra indent in DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL macro
    - Removed scan mask that included timestamp channel
    - Removed parent device assignment
    - Picked up Nuno's Reviewed-by
- Link to v2: https://lore.kernel.org/r/20231213-ad7380-mainline-v2-0-cd32150d84a3@baylibre.com

Changes in v2:
- dt-bindings:
    - Added new patch with generic spi-rx-bus-channels property
    - Added maxItems to reg property
    - Replaced adi,sdo-mode property with spi-rx-bus-channels
    - Made spi-rx-bus-channels property optional with default value of 1
      (this made the if: check more complex)
    - Changed example to use gpio for interrupt
- driver:
    - Fixed CONFIG_AD7380 in Makefile
    - rx_buf = st->scan_data.raw instead of rx_buf = &st->scan_data
    - Moved iio_push_to_buffers_with_timestamp() outside of if statement
    - Removed extra blank lines
    - Renamed regulator disable function
    - Dropped checking of adi,sdo-mode property (regardless of the actual
      wiring, we can always use 1-wire mode)
    - Added available_scan_masks
    - Added check for missing driver match data
- Link to v1: https://lore.kernel.org/r/20231208-ad7380-mainline-v1-0-2b33fe2f44ae@baylibre.com

To: Lars-Peter Clausen <lars@metafoo.de>
To: Michael Hennerich <Michael.Hennerich@analog.com>
To: Nuno Sá <nuno.sa@analog.com>
To: David Lechner <dlechner@baylibre.com>
To: Jonathan Cameron <jic23@kernel.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Liam Girdwood <lgirdwood@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-iio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
David Lechner (4):
      dt-bindings: iio: adc: Add binding for AD7380 ADCs
      iio: adc: ad7380: new driver for AD7380 ADCs
      dt-bindings: iio: adc: ad7380: add pseudo-differential parts
      iio: adc: ad7380: add support for pseudo-differential parts

Julien Stephan (3):
      iio: adc: ad7380: prepare for parts with more channels
      dt-bindings: iio: adc: ad7380: add support for ad738x-4 4 channels variants
      iio: adc: ad7380: add support for ad738x-4 4 channels variants

 .../devicetree/bindings/iio/adc/adi,ad7380.yaml    | 148 +++++
 MAINTAINERS                                        |  10 +
 drivers/iio/adc/Kconfig                            |  16 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/ad7380.c                           | 612 +++++++++++++++++++++
 5 files changed, 787 insertions(+)
---
base-commit: 9900e7a54764998ba3a22f06ec629f7b5fe0b422
change-id: 20240311-adding-new-ad738x-driver-5f9b54ad7c74

Best regards,
-- 
Julien Stephan <jstephan@baylibre.com>

[PATCH v7 1/7] dt-bindings: iio: adc: Add binding for AD7380 ADCs

[Julien Stephan]

From: David Lechner <dlechner@baylibre.com>

This adds a binding specification for the Analog Devices Inc. AD7380
family of ADCs.

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../devicetree/bindings/iio/adc/adi,ad7380.yaml    | 82 ++++++++++++++++++++++
 MAINTAINERS                                        |  9 +++
 2 files changed, 91 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
new file mode 100644
index 000000000000..5e1ee0ebe0a2
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
@@ -0,0 +1,82 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7380.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices Simultaneous Sampling Analog to Digital Converters
+
+maintainers:
+  - Michael Hennerich <Michael.Hennerich@analog.com>
+  - Nuno Sá <nuno.sa@analog.com>
+
+description: |
+  * https://www.analog.com/en/products/ad7380.html
+  * https://www.analog.com/en/products/ad7381.html
+
+$ref: /schemas/spi/spi-peripheral-props.yaml#
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7380
+      - adi,ad7381
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 80000000
+  spi-cpol: true
+  spi-cpha: true
+
+  vcc-supply:
+    description: A 3V to 3.6V supply that powers the chip.
+
+  vlogic-supply:
+    description:
+      A 1.65V to 3.6V supply for the logic pins.
+
+  refio-supply:
+    description:
+      A 2.5V to 3.3V supply for the external reference voltage. When omitted,
+      the internal 2.5V reference is used.
+
+  interrupts:
+    description:
+      When the device is using 1-wire mode, this property is used to optionally
+      specify the ALERT interrupt.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - vcc-supply
+  - vlogic-supply
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        adc@0 {
+            compatible = "adi,ad7380";
+            reg = <0>;
+
+            spi-cpol;
+            spi-cpha;
+            spi-max-frequency = <80000000>;
+
+            interrupts = <27 IRQ_TYPE_EDGE_FALLING>;
+            interrupt-parent = <&gpio0>;
+
+            vcc-supply = <&supply_3_3V>;
+            vlogic-supply = <&supply_3_3V>;
+            refio-supply = <&supply_2_5V>;
+        };
+    };
diff --git a/MAINTAINERS b/MAINTAINERS
index 758c202ec712..4f162600e982 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -427,6 +427,15 @@ W:	http://wiki.analog.com/AD7142
 W:	https://ez.analog.com/linux-software-drivers
 F:	drivers/input/misc/ad714x.c
 
+AD738X ADC DRIVER (AD7380/1/2/4)
+M:	Michael Hennerich <michael.hennerich@analog.com>
+M:	Nuno Sá <nuno.sa@analog.com>
+R:	David Lechner <dlechner@baylibre.com>
+S:	Supported
+W:	https://wiki.analog.com/resources/tools-software/linux-drivers/iio-adc/ad738x
+W:	https://ez.analog.com/linux-software-drivers
+F:	Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
+
 AD7877 TOUCHSCREEN DRIVER
 M:	Michael Hennerich <michael.hennerich@analog.com>
 S:	Supported

-- 
2.44.0

[PATCH v7 2/7] iio: adc: ad7380: new driver for AD7380 ADCs

[Julien Stephan]

From: David Lechner <dlechner@baylibre.com>

This adds a new driver for the AD7380 family ADCs.

The driver currently implements basic support for the AD7380, AD7381,
2-channel differential ADCs. Support for additional single-ended,
pseudo-differential and 4-channel chips that use the same register map
as well as additional features of the chip will be added in future patches.

Co-developed-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Signed-off-by: David Lechner <dlechner@baylibre.com>
[Julien Stephan: add datasheet links of supported parts]
[Julien Stephan: fix rx/tx buffer for regmap access]
[Julien Stephan: fix scale issue]
[Julien Stephan: use the new iio_device_claim_direct_scoped
instead of iio_device_claim_direct_mode]
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
 MAINTAINERS              |   1 +
 drivers/iio/adc/Kconfig  |  16 ++
 drivers/iio/adc/Makefile |   1 +
 drivers/iio/adc/ad7380.c | 438 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 456 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4f162600e982..315b3060946f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -435,6 +435,7 @@ S:	Supported
 W:	https://wiki.analog.com/resources/tools-software/linux-drivers/iio-adc/ad738x
 W:	https://ez.analog.com/linux-software-drivers
 F:	Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
+F:	drivers/iio/adc/ad7380.c
 
 AD7877 TOUCHSCREEN DRIVER
 M:	Michael Hennerich <michael.hennerich@analog.com>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 8db68b80b391..631386b037ae 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -155,6 +155,22 @@ config AD7298
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad7298.
 
+config AD7380
+	tristate "Analog Devices AD7380 ADC driver"
+	depends on SPI_MASTER
+	select IIO_BUFFER
+	select IIO_TRIGGER
+	select IIO_TRIGGERED_BUFFER
+	help
+	  AD7380 is a family of simultaneous sampling ADCs that share the same
+	  SPI register map and have similar pinouts.
+
+	  Say yes here to build support for Analog Devices AD7380 ADC and
+	  similar chips.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called ad7380.
+
 config AD7476
 	tristate "Analog Devices AD7476 1-channel ADCs driver and other similar devices from AD and TI"
 	depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index edb32ce2af02..bd3cbbb178fa 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_AD7291) += ad7291.o
 obj-$(CONFIG_AD7292) += ad7292.o
 obj-$(CONFIG_AD7298) += ad7298.o
 obj-$(CONFIG_AD7923) += ad7923.o
+obj-$(CONFIG_AD7380) += ad7380.o
 obj-$(CONFIG_AD7476) += ad7476.o
 obj-$(CONFIG_AD7606_IFACE_PARALLEL) += ad7606_par.o
 obj-$(CONFIG_AD7606_IFACE_SPI) += ad7606_spi.o
diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
new file mode 100644
index 000000000000..dac7e11755ff
--- /dev/null
+++ b/drivers/iio/adc/ad7380.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD738x Simultaneous Sampling SAR ADCs
+ *
+ * Copyright 2017 Analog Devices Inc.
+ * Copyright 2024 BayLibre, SAS
+ *
+ * Datasheets of supported parts:
+ * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+/* 2.5V internal reference voltage */
+#define AD7380_INTERNAL_REF_MV		2500
+
+/* reading and writing registers is more reliable at lower than max speed */
+#define AD7380_REG_WR_SPEED_HZ		10000000
+
+#define AD7380_REG_WR			BIT(15)
+#define AD7380_REG_REGADDR		GENMASK(14, 12)
+#define AD7380_REG_DATA			GENMASK(11, 0)
+
+#define AD7380_REG_ADDR_NOP		0x0
+#define AD7380_REG_ADDR_CONFIG1		0x1
+#define AD7380_REG_ADDR_CONFIG2		0x2
+#define AD7380_REG_ADDR_ALERT		0x3
+#define AD7380_REG_ADDR_ALERT_LOW_TH	0x4
+#define AD7380_REG_ADDR_ALERT_HIGH_TH	0x5
+
+#define AD7380_CONFIG1_OS_MODE		BIT(9)
+#define AD7380_CONFIG1_OSR		GENMASK(8, 6)
+#define AD7380_CONFIG1_CRC_W		BIT(5)
+#define AD7380_CONFIG1_CRC_R		BIT(4)
+#define AD7380_CONFIG1_ALERTEN		BIT(3)
+#define AD7380_CONFIG1_RES		BIT(2)
+#define AD7380_CONFIG1_REFSEL		BIT(1)
+#define AD7380_CONFIG1_PMODE		BIT(0)
+
+#define AD7380_CONFIG2_SDO2		GENMASK(9, 8)
+#define AD7380_CONFIG2_SDO		BIT(8)
+#define AD7380_CONFIG2_RESET		GENMASK(7, 0)
+
+#define AD7380_CONFIG2_RESET_SOFT	0x3C
+#define AD7380_CONFIG2_RESET_HARD	0xFF
+
+#define AD7380_ALERT_LOW_TH		GENMASK(11, 0)
+#define AD7380_ALERT_HIGH_TH		GENMASK(11, 0)
+
+struct ad7380_chip_info {
+	const char *name;
+	const struct iio_chan_spec *channels;
+	unsigned int num_channels;
+};
+
+#define AD7380_CHANNEL(index, bits) {				\
+	.type = IIO_VOLTAGE,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+	.indexed = 1,						\
+	.differential = 1,					\
+	.channel = 2 * (index),					\
+	.channel2 = 2 * (index) + 1,				\
+	.scan_index = (index),					\
+	.scan_type = {						\
+		.sign = 's',					\
+		.realbits = (bits),				\
+		.storagebits = 16,				\
+		.endianness = IIO_CPU,				\
+	},							\
+}
+
+#define DEFINE_AD7380_2_CHANNEL(name, bits)	\
+static const struct iio_chan_spec name[] = {	\
+	AD7380_CHANNEL(0, bits),		\
+	AD7380_CHANNEL(1, bits),		\
+	IIO_CHAN_SOFT_TIMESTAMP(2),		\
+}
+
+DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16);
+DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14);
+
+/* Since this is simultaneous sampling, we don't allow individual channels. */
+static const unsigned long ad7380_2_channel_scan_masks[] = {
+	GENMASK(1, 0),
+	0
+};
+
+static const struct ad7380_chip_info ad7380_chip_info = {
+	.name = "ad7380",
+	.channels = ad7380_channels,
+	.num_channels = ARRAY_SIZE(ad7380_channels),
+};
+
+static const struct ad7380_chip_info ad7381_chip_info = {
+	.name = "ad7381",
+	.channels = ad7381_channels,
+	.num_channels = ARRAY_SIZE(ad7381_channels),
+};
+
+struct ad7380_state {
+	const struct ad7380_chip_info *chip_info;
+	struct spi_device *spi;
+	struct regmap *regmap;
+	unsigned int vref_mv;
+	/*
+	 * DMA (thus cache coherency maintenance) requires the
+	 * transfer buffers to live in their own cache lines.
+	 * Make the buffer large enough for 2 16-bit samples and one 64-bit
+	 * aligned 64 bit timestamp.
+	 */
+	struct {
+		u16 raw[2];
+
+		s64 ts __aligned(8);
+	} scan_data __aligned(IIO_DMA_MINALIGN);
+	u16 tx;
+	u16 rx;
+};
+
+static int ad7380_regmap_reg_write(void *context, unsigned int reg,
+				   unsigned int val)
+{
+	struct ad7380_state *st = context;
+	struct spi_transfer xfer = {
+		.speed_hz = AD7380_REG_WR_SPEED_HZ,
+		.bits_per_word = 16,
+		.len = 2,
+		.tx_buf = &st->tx,
+	};
+
+	st->tx = FIELD_PREP(AD7380_REG_WR, 1) |
+		 FIELD_PREP(AD7380_REG_REGADDR, reg) |
+		 FIELD_PREP(AD7380_REG_DATA, val);
+
+	return spi_sync_transfer(st->spi, &xfer, 1);
+}
+
+static int ad7380_regmap_reg_read(void *context, unsigned int reg,
+				  unsigned int *val)
+{
+	struct ad7380_state *st = context;
+	struct spi_transfer xfers[] = {
+		{
+			.speed_hz = AD7380_REG_WR_SPEED_HZ,
+			.bits_per_word = 16,
+			.len = 2,
+			.tx_buf = &st->tx,
+			.cs_change = 1,
+			.cs_change_delay = {
+				.value = 10, /* t[CSH] */
+				.unit = SPI_DELAY_UNIT_NSECS,
+			},
+		}, {
+			.speed_hz = AD7380_REG_WR_SPEED_HZ,
+			.bits_per_word = 16,
+			.len = 2,
+			.rx_buf = &st->rx,
+		},
+	};
+	int ret;
+
+	st->tx = FIELD_PREP(AD7380_REG_WR, 0) |
+		 FIELD_PREP(AD7380_REG_REGADDR, reg) |
+		 FIELD_PREP(AD7380_REG_DATA, 0);
+
+	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+	if (ret < 0)
+		return ret;
+
+	*val = FIELD_GET(AD7380_REG_DATA, st->rx);
+
+	return 0;
+}
+
+static const struct regmap_config ad7380_regmap_config = {
+	.reg_bits = 3,
+	.val_bits = 12,
+	.reg_read = ad7380_regmap_reg_read,
+	.reg_write = ad7380_regmap_reg_write,
+	.max_register = AD7380_REG_ADDR_ALERT_HIGH_TH,
+	.can_sleep = true,
+};
+
+static int ad7380_debugfs_reg_access(struct iio_dev *indio_dev, u32 reg,
+				     u32 writeval, u32 *readval)
+{
+	iio_device_claim_direct_scoped(return  -EBUSY, indio_dev) {
+		struct ad7380_state *st = iio_priv(indio_dev);
+
+		if (readval)
+			return regmap_read(st->regmap, reg, readval);
+		else
+			return regmap_write(st->regmap, reg, writeval);
+	}
+	unreachable();
+}
+
+static irqreturn_t ad7380_trigger_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct ad7380_state *st = iio_priv(indio_dev);
+	struct spi_transfer xfer = {
+		.bits_per_word = st->chip_info->channels[0].scan_type.realbits,
+		.len = 4,
+		.rx_buf = st->scan_data.raw,
+	};
+	int ret;
+
+	ret = spi_sync_transfer(st->spi, &xfer, 1);
+	if (ret)
+		goto out;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, &st->scan_data,
+					   pf->timestamp);
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int ad7380_read_direct(struct ad7380_state *st,
+			      struct iio_chan_spec const *chan, int *val)
+{
+	struct spi_transfer xfers[] = {
+		/* toggle CS (no data xfer) to trigger a conversion */
+		{
+			.speed_hz = AD7380_REG_WR_SPEED_HZ,
+			.bits_per_word = chan->scan_type.realbits,
+			.delay = {
+				.value = 190, /* t[CONVERT] */
+				.unit = SPI_DELAY_UNIT_NSECS,
+			},
+			.cs_change = 1,
+			.cs_change_delay = {
+				.value = 10, /* t[CSH] */
+				.unit = SPI_DELAY_UNIT_NSECS,
+			},
+		},
+		/* then read both channels */
+		{
+			.speed_hz = AD7380_REG_WR_SPEED_HZ,
+			.bits_per_word = chan->scan_type.realbits,
+			.rx_buf = st->scan_data.raw,
+			.len = 4,
+		},
+	};
+	int ret;
+
+	ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+	if (ret < 0)
+		return ret;
+
+	*val = sign_extend32(st->scan_data.raw[chan->scan_index],
+			     chan->scan_type.realbits - 1);
+
+	return IIO_VAL_INT;
+}
+
+static int ad7380_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long info)
+{
+	struct ad7380_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		iio_device_claim_direct_scoped(return -EBUSY, indio_dev) {
+			return ad7380_read_direct(st, chan, val);
+		}
+		unreachable();
+	case IIO_CHAN_INFO_SCALE:
+		/*
+		 * According to the datasheet, the LSB size for fully differential ADC is
+		 * (2 × VREF) / 2^N, where N is the ADC resolution (i.e realbits)
+		 */
+		*val = st->vref_mv;
+		*val2 = chan->scan_type.realbits - 1;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
+}
+
+static const struct iio_info ad7380_info = {
+	.read_raw = &ad7380_read_raw,
+	.debugfs_reg_access = &ad7380_debugfs_reg_access,
+};
+
+static int ad7380_init(struct ad7380_state *st, struct regulator *vref)
+{
+	int ret;
+
+	/* perform hard reset */
+	ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
+				 AD7380_CONFIG2_RESET,
+				 FIELD_PREP(AD7380_CONFIG2_RESET,
+					    AD7380_CONFIG2_RESET_HARD));
+	if (ret < 0)
+		return ret;
+
+	/* select internal or external reference voltage */
+	ret = regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG1,
+				 AD7380_CONFIG1_REFSEL,
+				 FIELD_PREP(AD7380_CONFIG1_REFSEL,
+					    vref ? 1 : 0));
+	if (ret < 0)
+		return ret;
+
+	/* SPI 1-wire mode */
+	return regmap_update_bits(st->regmap, AD7380_REG_ADDR_CONFIG2,
+				  AD7380_CONFIG2_SDO,
+				  FIELD_PREP(AD7380_CONFIG2_SDO, 1));
+}
+
+static void ad7380_regulator_disable(void *p)
+{
+	regulator_disable(p);
+}
+
+static int ad7380_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct ad7380_state *st;
+	struct regulator *vref;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+	st->spi = spi;
+	st->chip_info = spi_get_device_match_data(spi);
+	if (!st->chip_info)
+		return dev_err_probe(&spi->dev, -EINVAL, "missing match data\n");
+
+	vref = devm_regulator_get_optional(&spi->dev, "refio");
+	if (IS_ERR(vref)) {
+		if (PTR_ERR(vref) != -ENODEV)
+			return dev_err_probe(&spi->dev, PTR_ERR(vref),
+					     "Failed to get refio regulator\n");
+
+		vref = NULL;
+	}
+
+	/*
+	 * If there is no REFIO supply, then it means that we are using
+	 * the internal 2.5V reference, otherwise REFIO is reference voltage.
+	 */
+	if (vref) {
+		ret = regulator_enable(vref);
+		if (ret)
+			return ret;
+
+		ret = devm_add_action_or_reset(&spi->dev,
+					       ad7380_regulator_disable, vref);
+		if (ret)
+			return ret;
+
+		ret = regulator_get_voltage(vref);
+		if (ret < 0)
+			return ret;
+
+		st->vref_mv = ret / 1000;
+	} else {
+		st->vref_mv = AD7380_INTERNAL_REF_MV;
+	}
+
+	st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config);
+	if (IS_ERR(st->regmap))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->regmap),
+				     "failed to allocate register map\n");
+
+	indio_dev->channels = st->chip_info->channels;
+	indio_dev->num_channels = st->chip_info->num_channels;
+	indio_dev->name = st->chip_info->name;
+	indio_dev->info = &ad7380_info;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->available_scan_masks = ad7380_2_channel_scan_masks;
+
+	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+					      iio_pollfunc_store_time,
+					      ad7380_trigger_handler, NULL);
+	if (ret)
+		return ret;
+
+	ret = ad7380_init(st, vref);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct of_device_id ad7380_of_match_table[] = {
+	{ .compatible = "adi,ad7380", .data = &ad7380_chip_info },
+	{ .compatible = "adi,ad7381", .data = &ad7381_chip_info },
+	{ }
+};
+
+static const struct spi_device_id ad7380_id_table[] = {
+	{ "ad7380", (kernel_ulong_t)&ad7380_chip_info },
+	{ "ad7381", (kernel_ulong_t)&ad7381_chip_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, ad7380_id_table);
+
+static struct spi_driver ad7380_driver = {
+	.driver = {
+		.name = "ad7380",
+		.of_match_table = ad7380_of_match_table,
+	},
+	.probe = ad7380_probe,
+	.id_table = ad7380_id_table,
+};
+module_spi_driver(ad7380_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD738x ADC driver");
+MODULE_LICENSE("GPL");

-- 
2.44.0

[PATCH v7 3/7] dt-bindings: iio: adc: ad7380: add pseudo-differential parts

[Julien Stephan]

From: David Lechner <dlechner@baylibre.com>

Adding AD7383 and AD7384 compatible parts that are pseudo-differential.

Pseudo-differential require common mode voltage supplies, so add them
conditionally

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../devicetree/bindings/iio/adc/adi,ad7380.yaml    | 32 ++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
index 5e1ee0ebe0a2..de3d28a021ae 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
@@ -13,6 +13,8 @@ maintainers:
 description: |
   * https://www.analog.com/en/products/ad7380.html
   * https://www.analog.com/en/products/ad7381.html
+  * https://www.analog.com/en/products/ad7383.html
+  * https://www.analog.com/en/products/ad7384.html
 
 $ref: /schemas/spi/spi-peripheral-props.yaml#
 
@@ -21,6 +23,8 @@ properties:
     enum:
       - adi,ad7380
       - adi,ad7381
+      - adi,ad7383
+      - adi,ad7384
 
   reg:
     maxItems: 1
@@ -42,6 +46,16 @@ properties:
       A 2.5V to 3.3V supply for the external reference voltage. When omitted,
       the internal 2.5V reference is used.
 
+  aina-supply:
+    description:
+      The common mode voltage supply for the AINA- pin on pseudo-differential
+      chips.
+
+  ainb-supply:
+    description:
+      The common mode voltage supply for the AINB- pin on pseudo-differential
+      chips.
+
   interrupts:
     description:
       When the device is using 1-wire mode, this property is used to optionally
@@ -56,6 +70,24 @@ required:
 
 unevaluatedProperties: false
 
+allOf:
+  # pseudo-differential chips require common mode voltage supplies,
+  # true differential chips don't use them
+  - if:
+      properties:
+        compatible:
+          enum:
+            - adi,ad7383
+            - adi,ad7384
+    then:
+      required:
+        - aina-supply
+        - ainb-supply
+    else:
+      properties:
+        aina-supply: false
+        ainb-supply: false
+
 examples:
   - |
     #include <dt-bindings/interrupt-controller/irq.h>

-- 
2.44.0

[PATCH v7 4/7] iio: adc: ad7380: add support for pseudo-differential parts

[Julien Stephan]

From: David Lechner <dlechner@baylibre.com>

Add support for AD7383, AD7384 pseudo-differential compatible parts.
Pseudo differential parts require common mode voltage supplies so add
the support for them and add the support of IIO_CHAN_INFO_OFFSET to
retrieve the offset

Signed-off-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
 drivers/iio/adc/ad7380.c | 110 ++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 94 insertions(+), 16 deletions(-)

diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index dac7e11755ff..4ad283cf970d 100644
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -7,6 +7,7 @@
  *
  * Datasheets of supported parts:
  * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf
+ * ad7383/4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-7384.pdf
  */
 
 #include <linux/bitfield.h>
@@ -66,16 +67,19 @@ struct ad7380_chip_info {
 	const char *name;
 	const struct iio_chan_spec *channels;
 	unsigned int num_channels;
+	const char * const *vcm_supplies;
+	unsigned int num_vcm_supplies;
 };
 
-#define AD7380_CHANNEL(index, bits) {				\
+#define AD7380_CHANNEL(index, bits, diff) {			\
 	.type = IIO_VOLTAGE,					\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |		\
+		((diff) ? 0 : BIT(IIO_CHAN_INFO_OFFSET)),	\
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
 	.indexed = 1,						\
-	.differential = 1,					\
-	.channel = 2 * (index),					\
-	.channel2 = 2 * (index) + 1,				\
+	.differential = (diff),					\
+	.channel = (diff) ? (2 * (index)) : (index),		\
+	.channel2 = (diff) ? (2 * (index) + 1) : 0,		\
 	.scan_index = (index),					\
 	.scan_type = {						\
 		.sign = 's',					\
@@ -85,15 +89,23 @@ struct ad7380_chip_info {
 	},							\
 }
 
-#define DEFINE_AD7380_2_CHANNEL(name, bits)	\
-static const struct iio_chan_spec name[] = {	\
-	AD7380_CHANNEL(0, bits),		\
-	AD7380_CHANNEL(1, bits),		\
-	IIO_CHAN_SOFT_TIMESTAMP(2),		\
+#define DEFINE_AD7380_2_CHANNEL(name, bits, diff)	\
+static const struct iio_chan_spec name[] = {		\
+	AD7380_CHANNEL(0, bits, diff),			\
+	AD7380_CHANNEL(1, bits, diff),			\
+	IIO_CHAN_SOFT_TIMESTAMP(2),			\
 }
 
-DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16);
-DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14);
+/* fully differential */
+DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16, 1);
+DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14, 1);
+/* pseudo differential */
+DEFINE_AD7380_2_CHANNEL(ad7383_channels, 16, 0);
+DEFINE_AD7380_2_CHANNEL(ad7384_channels, 14, 0);
+
+static const char * const ad7380_2_channel_vcm_supplies[] = {
+	"aina", "ainb",
+};
 
 /* Since this is simultaneous sampling, we don't allow individual channels. */
 static const unsigned long ad7380_2_channel_scan_masks[] = {
@@ -113,11 +125,28 @@ static const struct ad7380_chip_info ad7381_chip_info = {
 	.num_channels = ARRAY_SIZE(ad7381_channels),
 };
 
+static const struct ad7380_chip_info ad7383_chip_info = {
+	.name = "ad7383",
+	.channels = ad7383_channels,
+	.num_channels = ARRAY_SIZE(ad7383_channels),
+	.vcm_supplies = ad7380_2_channel_vcm_supplies,
+	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
+};
+
+static const struct ad7380_chip_info ad7384_chip_info = {
+	.name = "ad7384",
+	.channels = ad7384_channels,
+	.num_channels = ARRAY_SIZE(ad7384_channels),
+	.vcm_supplies = ad7380_2_channel_vcm_supplies,
+	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
+};
+
 struct ad7380_state {
 	const struct ad7380_chip_info *chip_info;
 	struct spi_device *spi;
 	struct regmap *regmap;
 	unsigned int vref_mv;
+	unsigned int vcm_mv[2];
 	/*
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
@@ -288,13 +317,24 @@ static int ad7380_read_raw(struct iio_dev *indio_dev,
 		unreachable();
 	case IIO_CHAN_INFO_SCALE:
 		/*
-		 * According to the datasheet, the LSB size for fully differential ADC is
-		 * (2 × VREF) / 2^N, where N is the ADC resolution (i.e realbits)
+		 * According to the datasheet, the LSB size is:
+		 *    * (2 × VREF) / 2^N, for differential chips
+		 *    * VREF / 2^N, for pseudo-differential chips
+		 * where N is the ADC resolution (i.e realbits)
 		 */
 		*val = st->vref_mv;
-		*val2 = chan->scan_type.realbits - 1;
+		*val2 = chan->scan_type.realbits - chan->differential;
 
 		return IIO_VAL_FRACTIONAL_LOG2;
+	case IIO_CHAN_INFO_OFFSET:
+		/*
+		 * According to IIO ABI, offset is applied before scale,
+		 * so offset is: vcm_mv / scale
+		 */
+		*val = st->vcm_mv[chan->channel] * (1 << chan->scan_type.realbits)
+			/ st->vref_mv;
+
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
@@ -341,7 +381,7 @@ static int ad7380_probe(struct spi_device *spi)
 	struct iio_dev *indio_dev;
 	struct ad7380_state *st;
 	struct regulator *vref;
-	int ret;
+	int ret, i;
 
 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
 	if (!indio_dev)
@@ -385,6 +425,40 @@ static int ad7380_probe(struct spi_device *spi)
 		st->vref_mv = AD7380_INTERNAL_REF_MV;
 	}
 
+	if (st->chip_info->num_vcm_supplies > ARRAY_SIZE(st->vcm_mv))
+		return dev_err_probe(&spi->dev, -EINVAL,
+				     "invalid number of VCM supplies\n");
+
+	/*
+	 * pseudo-differential chips have common mode supplies for the negative
+	 * input pin.
+	 */
+	for (i = 0; i < st->chip_info->num_vcm_supplies; i++) {
+		struct regulator *vcm;
+
+		vcm = devm_regulator_get(&spi->dev,
+					 st->chip_info->vcm_supplies[i]);
+		if (IS_ERR(vcm))
+			return dev_err_probe(&spi->dev, PTR_ERR(vcm),
+					     "Failed to get %s regulator\n",
+					     st->chip_info->vcm_supplies[i]);
+
+		ret = regulator_enable(vcm);
+		if (ret)
+			return ret;
+
+		ret = devm_add_action_or_reset(&spi->dev,
+					       ad7380_regulator_disable, vcm);
+		if (ret)
+			return ret;
+
+		ret = regulator_get_voltage(vcm);
+		if (ret < 0)
+			return ret;
+
+		st->vcm_mv[i] = ret / 1000;
+	}
+
 	st->regmap = devm_regmap_init(&spi->dev, NULL, st, &ad7380_regmap_config);
 	if (IS_ERR(st->regmap))
 		return dev_err_probe(&spi->dev, PTR_ERR(st->regmap),
@@ -413,12 +487,16 @@ static int ad7380_probe(struct spi_device *spi)
 static const struct of_device_id ad7380_of_match_table[] = {
 	{ .compatible = "adi,ad7380", .data = &ad7380_chip_info },
 	{ .compatible = "adi,ad7381", .data = &ad7381_chip_info },
+	{ .compatible = "adi,ad7383", .data = &ad7383_chip_info },
+	{ .compatible = "adi,ad7384", .data = &ad7384_chip_info },
 	{ }
 };
 
 static const struct spi_device_id ad7380_id_table[] = {
 	{ "ad7380", (kernel_ulong_t)&ad7380_chip_info },
 	{ "ad7381", (kernel_ulong_t)&ad7381_chip_info },
+	{ "ad7383", (kernel_ulong_t)&ad7383_chip_info },
+	{ "ad7384", (kernel_ulong_t)&ad7384_chip_info },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, ad7380_id_table);

-- 
2.44.0

[PATCH v7 5/7] iio: adc: ad7380: prepare for parts with more channels

[Julien Stephan]

The current driver supports only parts with 2 channels.
In order to prepare the support of new compatible ADCs with more
channels, this commit:
  - defines MAX_NUM_CHANNEL to specify the maximum number of
    channels currently supported by the driver
  - adds available_scan_mask member in ad7380_chip_info structure
  - fixes spi xfer struct len depending on number of channels
  - fixes scan_data.raw buffer size to handle more channels
  - adds a timing specifications structure in ad7380_chip_info structure

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
 drivers/iio/adc/ad7380.c | 43 +++++++++++++++++++++++++++++++++----------
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index 4ad283cf970d..790d08c90ad0 100644
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -27,6 +27,7 @@
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 
+#define MAX_NUM_CHANNELS		2
 /* 2.5V internal reference voltage */
 #define AD7380_INTERNAL_REF_MV		2500
 
@@ -63,12 +64,19 @@
 #define AD7380_ALERT_LOW_TH		GENMASK(11, 0)
 #define AD7380_ALERT_HIGH_TH		GENMASK(11, 0)
 
+#define T_CONVERT_NS 190		/* conversion time */
+struct ad7380_timing_specs {
+	const unsigned int t_csh_ns;	/* CS minimum high time */
+};
+
 struct ad7380_chip_info {
 	const char *name;
 	const struct iio_chan_spec *channels;
 	unsigned int num_channels;
 	const char * const *vcm_supplies;
 	unsigned int num_vcm_supplies;
+	const unsigned long *available_scan_masks;
+	const struct ad7380_timing_specs *timing_specs;
 };
 
 #define AD7380_CHANNEL(index, bits, diff) {			\
@@ -113,16 +121,24 @@ static const unsigned long ad7380_2_channel_scan_masks[] = {
 	0
 };
 
+static const struct ad7380_timing_specs ad7380_timing = {
+	.t_csh_ns = 10,
+};
+
 static const struct ad7380_chip_info ad7380_chip_info = {
 	.name = "ad7380",
 	.channels = ad7380_channels,
 	.num_channels = ARRAY_SIZE(ad7380_channels),
+	.available_scan_masks = ad7380_2_channel_scan_masks,
+	.timing_specs = &ad7380_timing,
 };
 
 static const struct ad7380_chip_info ad7381_chip_info = {
 	.name = "ad7381",
 	.channels = ad7381_channels,
 	.num_channels = ARRAY_SIZE(ad7381_channels),
+	.available_scan_masks = ad7380_2_channel_scan_masks,
+	.timing_specs = &ad7380_timing,
 };
 
 static const struct ad7380_chip_info ad7383_chip_info = {
@@ -131,6 +147,8 @@ static const struct ad7380_chip_info ad7383_chip_info = {
 	.num_channels = ARRAY_SIZE(ad7383_channels),
 	.vcm_supplies = ad7380_2_channel_vcm_supplies,
 	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
+	.available_scan_masks = ad7380_2_channel_scan_masks,
+	.timing_specs = &ad7380_timing,
 };
 
 static const struct ad7380_chip_info ad7384_chip_info = {
@@ -139,6 +157,8 @@ static const struct ad7380_chip_info ad7384_chip_info = {
 	.num_channels = ARRAY_SIZE(ad7384_channels),
 	.vcm_supplies = ad7380_2_channel_vcm_supplies,
 	.num_vcm_supplies = ARRAY_SIZE(ad7380_2_channel_vcm_supplies),
+	.available_scan_masks = ad7380_2_channel_scan_masks,
+	.timing_specs = &ad7380_timing,
 };
 
 struct ad7380_state {
@@ -146,15 +166,16 @@ struct ad7380_state {
 	struct spi_device *spi;
 	struct regmap *regmap;
 	unsigned int vref_mv;
-	unsigned int vcm_mv[2];
+	unsigned int vcm_mv[MAX_NUM_CHANNELS];
 	/*
 	 * DMA (thus cache coherency maintenance) requires the
 	 * transfer buffers to live in their own cache lines.
-	 * Make the buffer large enough for 2 16-bit samples and one 64-bit
+	 * Make the buffer large enough for MAX_NUM_CHANNELS 16-bit samples and one 64-bit
 	 * aligned 64 bit timestamp.
+	 * As MAX_NUM_CHANNELS is 2 the layout of the structure is the same for all parts
 	 */
 	struct {
-		u16 raw[2];
+		u16 raw[MAX_NUM_CHANNELS];
 
 		s64 ts __aligned(8);
 	} scan_data __aligned(IIO_DMA_MINALIGN);
@@ -192,7 +213,7 @@ static int ad7380_regmap_reg_read(void *context, unsigned int reg,
 			.tx_buf = &st->tx,
 			.cs_change = 1,
 			.cs_change_delay = {
-				.value = 10, /* t[CSH] */
+				.value = st->chip_info->timing_specs->t_csh_ns,
 				.unit = SPI_DELAY_UNIT_NSECS,
 			},
 		}, {
@@ -247,7 +268,8 @@ static irqreturn_t ad7380_trigger_handler(int irq, void *p)
 	struct ad7380_state *st = iio_priv(indio_dev);
 	struct spi_transfer xfer = {
 		.bits_per_word = st->chip_info->channels[0].scan_type.realbits,
-		.len = 4,
+		.len = (st->chip_info->num_channels - 1) *
+		       BITS_TO_BYTES(st->chip_info->channels->scan_type.storagebits),
 		.rx_buf = st->scan_data.raw,
 	};
 	int ret;
@@ -274,21 +296,22 @@ static int ad7380_read_direct(struct ad7380_state *st,
 			.speed_hz = AD7380_REG_WR_SPEED_HZ,
 			.bits_per_word = chan->scan_type.realbits,
 			.delay = {
-				.value = 190, /* t[CONVERT] */
+				.value = T_CONVERT_NS,
 				.unit = SPI_DELAY_UNIT_NSECS,
 			},
 			.cs_change = 1,
 			.cs_change_delay = {
-				.value = 10, /* t[CSH] */
+				.value = st->chip_info->timing_specs->t_csh_ns,
 				.unit = SPI_DELAY_UNIT_NSECS,
 			},
 		},
-		/* then read both channels */
+		/* then read all channels */
 		{
 			.speed_hz = AD7380_REG_WR_SPEED_HZ,
 			.bits_per_word = chan->scan_type.realbits,
 			.rx_buf = st->scan_data.raw,
-			.len = 4,
+			.len = (st->chip_info->num_channels - 1) *
+			       ((chan->scan_type.storagebits > 16) ? 4 : 2),
 		},
 	};
 	int ret;
@@ -469,7 +492,7 @@ static int ad7380_probe(struct spi_device *spi)
 	indio_dev->name = st->chip_info->name;
 	indio_dev->info = &ad7380_info;
 	indio_dev->modes = INDIO_DIRECT_MODE;
-	indio_dev->available_scan_masks = ad7380_2_channel_scan_masks;
+	indio_dev->available_scan_masks = st->chip_info->available_scan_masks;
 
 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
 					      iio_pollfunc_store_time,

-- 
2.44.0

[PATCH v7 6/7] dt-bindings: iio: adc: ad7380: add support for ad738x-4 4 channels variants

[Julien Stephan]

Add compatible support for ad7380/1/3/4-4 parts which are 4 channels
variants from ad7380/1/3/4

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
---
 .../devicetree/bindings/iio/adc/adi,ad7380.yaml    | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
index de3d28a021ae..899b777017ce 100644
--- a/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
@@ -15,6 +15,10 @@ description: |
   * https://www.analog.com/en/products/ad7381.html
   * https://www.analog.com/en/products/ad7383.html
   * https://www.analog.com/en/products/ad7384.html
+  * https://www.analog.com/en/products/ad7380-4.html
+  * https://www.analog.com/en/products/ad7381-4.html
+  * https://www.analog.com/en/products/ad7383-4.html
+  * https://www.analog.com/en/products/ad7384-4.html
 
 $ref: /schemas/spi/spi-peripheral-props.yaml#
 
@@ -25,6 +29,10 @@ properties:
       - adi,ad7381
       - adi,ad7383
       - adi,ad7384
+      - adi,ad7380-4
+      - adi,ad7381-4
+      - adi,ad7383-4
+      - adi,ad7384-4
 
   reg:
     maxItems: 1
@@ -56,6 +64,16 @@ properties:
       The common mode voltage supply for the AINB- pin on pseudo-differential
       chips.
 
+  ainc-supply:
+    description:
+      The common mode voltage supply for the AINC- pin on pseudo-differential
+      chips.
+
+  aind-supply:
+    description:
+      The common mode voltage supply for the AIND- pin on pseudo-differential
+      chips.
+
   interrupts:
     description:
       When the device is using 1-wire mode, this property is used to optionally
@@ -79,6 +97,8 @@ allOf:
           enum:
             - adi,ad7383
             - adi,ad7384
+            - adi,ad7383-4
+            - adi,ad7384-4
     then:
       required:
         - aina-supply
@@ -87,6 +107,20 @@ allOf:
       properties:
         aina-supply: false
         ainb-supply: false
+  - if:
+      properties:
+        compatible:
+          enum:
+            - adi,ad7383-4
+            - adi,ad7384-4
+    then:
+      required:
+        - ainc-supply
+        - aind-supply
+    else:
+      properties:
+        ainc-supply: false
+        aind-supply: false
 
 examples:
   - |

-- 
2.44.0

[PATCH v7 7/7] iio: adc: ad7380: add support for ad738x-4 4 channels variants

[Julien Stephan]

Add support for ad7380/1/2/3-4 parts which are 4 channels
variants from ad7380/1/2/3

Signed-off-by: Julien Stephan <jstephan@baylibre.com>
---
 drivers/iio/adc/ad7380.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 75 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/adc/ad7380.c b/drivers/iio/adc/ad7380.c
index 790d08c90ad0..6b0b1b0be363 100644
--- a/drivers/iio/adc/ad7380.c
+++ b/drivers/iio/adc/ad7380.c
@@ -8,6 +8,9 @@
  * Datasheets of supported parts:
  * ad7380/1 : https://www.analog.com/media/en/technical-documentation/data-sheets/AD7380-7381.pdf
  * ad7383/4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-7384.pdf
+ * ad7380-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7380-4.pdf
+ * ad7381-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7381-4.pdf
+ * ad7383/4-4 : https://www.analog.com/media/en/technical-documentation/data-sheets/ad7383-4-ad7384-4.pdf
  */
 
 #include <linux/bitfield.h>
@@ -27,7 +30,7 @@
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/triggered_buffer.h>
 
-#define MAX_NUM_CHANNELS		2
+#define MAX_NUM_CHANNELS		4
 /* 2.5V internal reference voltage */
 #define AD7380_INTERNAL_REF_MV		2500
 
@@ -104,27 +107,53 @@ static const struct iio_chan_spec name[] = {		\
 	IIO_CHAN_SOFT_TIMESTAMP(2),			\
 }
 
+#define DEFINE_AD7380_4_CHANNEL(name, bits, diff)	\
+static const struct iio_chan_spec name[] = {		\
+	AD7380_CHANNEL(0, bits, diff),			\
+	AD7380_CHANNEL(1, bits, diff),			\
+	AD7380_CHANNEL(2, bits, diff),			\
+	AD7380_CHANNEL(3, bits, diff),			\
+	IIO_CHAN_SOFT_TIMESTAMP(4),			\
+}
+
 /* fully differential */
 DEFINE_AD7380_2_CHANNEL(ad7380_channels, 16, 1);
 DEFINE_AD7380_2_CHANNEL(ad7381_channels, 14, 1);
+DEFINE_AD7380_4_CHANNEL(ad7380_4_channels, 16, 1);
+DEFINE_AD7380_4_CHANNEL(ad7381_4_channels, 14, 1);
 /* pseudo differential */
 DEFINE_AD7380_2_CHANNEL(ad7383_channels, 16, 0);
 DEFINE_AD7380_2_CHANNEL(ad7384_channels, 14, 0);
+DEFINE_AD7380_4_CHANNEL(ad7383_4_channels, 16, 0);
+DEFINE_AD7380_4_CHANNEL(ad7384_4_channels, 14, 0);
 
 static const char * const ad7380_2_channel_vcm_supplies[] = {
 	"aina", "ainb",
 };
 
+static const char * const ad7380_4_channel_vcm_supplies[] = {
+	"aina", "ainb", "ainc", "aind",
+};
+
 /* Since this is simultaneous sampling, we don't allow individual channels. */
 static const unsigned long ad7380_2_channel_scan_masks[] = {
 	GENMASK(1, 0),
 	0
 };
 
+static const unsigned long ad7380_4_channel_scan_masks[] = {
+	GENMASK(3, 0),
+	0
+};
+
 static const struct ad7380_timing_specs ad7380_timing = {
 	.t_csh_ns = 10,
 };
 
+static const struct ad7380_timing_specs ad7380_4_timing = {
+	.t_csh_ns = 20,
+};
+
 static const struct ad7380_chip_info ad7380_chip_info = {
 	.name = "ad7380",
 	.channels = ad7380_channels,
@@ -161,6 +190,42 @@ static const struct ad7380_chip_info ad7384_chip_info = {
 	.timing_specs = &ad7380_timing,
 };
 
+static const struct ad7380_chip_info ad7380_4_chip_info = {
+	.name = "ad7380-4",
+	.channels = ad7380_4_channels,
+	.num_channels = ARRAY_SIZE(ad7380_4_channels),
+	.available_scan_masks = ad7380_4_channel_scan_masks,
+	.timing_specs = &ad7380_4_timing,
+};
+
+static const struct ad7380_chip_info ad7381_4_chip_info = {
+	.name = "ad7381-4",
+	.channels = ad7381_4_channels,
+	.num_channels = ARRAY_SIZE(ad7381_4_channels),
+	.available_scan_masks = ad7380_4_channel_scan_masks,
+	.timing_specs = &ad7380_4_timing,
+};
+
+static const struct ad7380_chip_info ad7383_4_chip_info = {
+	.name = "ad7383-4",
+	.channels = ad7383_4_channels,
+	.num_channels = ARRAY_SIZE(ad7383_4_channels),
+	.vcm_supplies = ad7380_4_channel_vcm_supplies,
+	.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
+	.available_scan_masks = ad7380_4_channel_scan_masks,
+	.timing_specs = &ad7380_4_timing,
+};
+
+static const struct ad7380_chip_info ad7384_4_chip_info = {
+	.name = "ad7384-4",
+	.channels = ad7384_4_channels,
+	.num_channels = ARRAY_SIZE(ad7384_4_channels),
+	.vcm_supplies = ad7380_4_channel_vcm_supplies,
+	.num_vcm_supplies = ARRAY_SIZE(ad7380_4_channel_vcm_supplies),
+	.available_scan_masks = ad7380_4_channel_scan_masks,
+	.timing_specs = &ad7380_4_timing,
+};
+
 struct ad7380_state {
 	const struct ad7380_chip_info *chip_info;
 	struct spi_device *spi;
@@ -172,7 +237,7 @@ struct ad7380_state {
 	 * transfer buffers to live in their own cache lines.
 	 * Make the buffer large enough for MAX_NUM_CHANNELS 16-bit samples and one 64-bit
 	 * aligned 64 bit timestamp.
-	 * As MAX_NUM_CHANNELS is 2 the layout of the structure is the same for all parts
+	 * As MAX_NUM_CHANNELS is 4 the layout of the structure is the same for all parts
 	 */
 	struct {
 		u16 raw[MAX_NUM_CHANNELS];
@@ -512,6 +577,10 @@ static const struct of_device_id ad7380_of_match_table[] = {
 	{ .compatible = "adi,ad7381", .data = &ad7381_chip_info },
 	{ .compatible = "adi,ad7383", .data = &ad7383_chip_info },
 	{ .compatible = "adi,ad7384", .data = &ad7384_chip_info },
+	{ .compatible = "adi,ad7380-4", .data = &ad7380_4_chip_info },
+	{ .compatible = "adi,ad7381-4", .data = &ad7381_4_chip_info },
+	{ .compatible = "adi,ad7383-4", .data = &ad7383_4_chip_info },
+	{ .compatible = "adi,ad7384-4", .data = &ad7384_4_chip_info },
 	{ }
 };
 
@@ -520,6 +589,10 @@ static const struct spi_device_id ad7380_id_table[] = {
 	{ "ad7381", (kernel_ulong_t)&ad7381_chip_info },
 	{ "ad7383", (kernel_ulong_t)&ad7383_chip_info },
 	{ "ad7384", (kernel_ulong_t)&ad7384_chip_info },
+	{ "ad7380-4", (kernel_ulong_t)&ad7380_4_chip_info },
+	{ "ad7381-4", (kernel_ulong_t)&ad7381_4_chip_info },
+	{ "ad7383-4", (kernel_ulong_t)&ad7383_4_chip_info },
+	{ "ad7384-4", (kernel_ulong_t)&ad7384_4_chip_info },
 	{ }
 };
 MODULE_DEVICE_TABLE(spi, ad7380_id_table);

-- 
2.44.0

Re: [PATCH v7 0/7] iio: adc: add new ad7380 driver

[Jonathan Cameron]

On Tue, 28 May 2024 16:20:27 +0200
Julien Stephan <jstephan@baylibre.com> wrote:

> Taking over this series with David Lechner's approval, to add some
> fixes, proper handling of pseudo differential parts and
> some extra commits to add support for 4-channel compatible parts.
> 
> Here is David's cover letter:
> 
> This series is adding a new driver for the Analog Devices Inc. AD7380,
> AD7381, AD7383, and AD7384 ADCs. These chips are part of a family of
> simultaneous sampling SAR ADCs.
> 
> To keep things simple, the initial driver implementation only supports
> the 2/4-channel differential chips listed above. There are also 4-channel
> single-ended chips in the family that can be added later.
> 
> Furthermore, the driver is just implementing basic support for capturing
> data. Additional features like interrupts, CRC, etc. can be added later.
> 
> This work is being done by BayLibre and on behalf of Analog Devices Inc.
> hence the maintainers are @analog.com.
> 
Applied + I'll pick up the series David posted with oversampling support
now I have the precursor!  A tiny bit of noise in this one because
of the reordering of the adc/Makefile

Thanks,