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.
One quirk of these chips is that since they are simultaneous sampling,
they have multiple SPI data output lines that allow transferring two
data words (one for each input channel) at the same time. So a new
generic devicetree binding is added to describe this sort of SPI bus
configuration.
To keep things simple, the initial driver implementation only supports
the 2-channel differential chips listed above. There are also 4-channel
differential chips and 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.
Also, FYI, this driver will also be used as the base for an upcoming
series adding AXI SPI Engine offload support for these chips along with
[1].
This work is being done by BayLibre and on behalf of Analog Devices Inc.
hence the maintainers are @analog.com.
[1]: https://lore.kernel.org/linux-spi/[email protected]/
---
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/[email protected]
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/[email protected]
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/[email protected]
---
David Lechner (2):
dt-bindings: iio: adc: Add binding for AD7380 ADCs
iio: adc: ad7380: new driver for AD7380 ADCs
.../devicetree/bindings/iio/adc/adi,ad7380.yaml | 86 ++++
MAINTAINERS | 10 +
drivers/iio/adc/Kconfig | 16 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7380.c | 462 +++++++++++++++++++++
5 files changed, 575 insertions(+)
---
base-commit: 18f78b5e609b19b56237f0dae47068d44b8b0ecd
change-id: 20231208-ad7380-mainline-e6c4fa7dbedd
Best regards,
--
David Lechner <[email protected]>
This adds a binding specification for the Analog Devices Inc. AD7380
family of ADCs.
Signed-off-by: David Lechner <[email protected]>
---
As discussed in [1], the proposed spi-rx-bus-channels property is a complex
new SPI core feature, so it was nacked for now on the grounds that it should
be accepted without the corresponding SPI core changes. I dropped the Reviewed-by
since no DT maintainers responded on that thread.
[1]: https://lore.kernel.org/linux-spi/[email protected]/
Changes in v4:
- Dropped spi-rx-bus-channels property.
Changes in v3:
- Picked up Conor's Reviewed-By on the adi,ad7380 bindings
Changes in v2:
- 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
.../devicetree/bindings/iio/adc/adi,ad7380.yaml | 86 ++++++++++++++++++++++
MAINTAINERS | 9 +++
2 files changed, 95 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..5a70d1ee768b
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7380.yaml
@@ -0,0 +1,86 @@
+# 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 <[email protected]>
+ - Nuno Sá <[email protected]>
+
+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#
+
+properties:
+ compatible:
+ enum:
+ - adi,ad7380
+ - adi,ad7381
+ - adi,ad7383
+ - adi,ad7384
+
+ 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 fe1f6f97f96a..e2a998be5879 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -430,6 +430,15 @@ 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 <[email protected]>
+M: Nuno Sá <[email protected]>
+R: David Lechner <[email protected]>
+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 <[email protected]>
S: Supported
--
2.43.0
This adds a new driver for the AD7380 family ADCs.
The driver currently implements basic support for the AD7380, AD7381,
AD7383, and AD7384 2-channel differential ADCs. Support for additional
single-ended 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 <[email protected]>
Signed-off-by: Stefan Popa <[email protected]>
Reviewed-by: Nuno Sa <[email protected]>
Signed-off-by: David Lechner <[email protected]>
---
Changes in v4: none
Changes in v3:
- 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
Changes in v2:
- 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
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 16 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7380.c | 462 +++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 480 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index e2a998be5879..5a54620a31b8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -438,6 +438,7 @@ 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 <[email protected]>
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 35f9867da12c..cbfd626712e3 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -122,6 +122,22 @@ 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 bee11d442af4..9c921c497655 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -16,6 +16,7 @@ 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..80712aaa9548
--- /dev/null
+++ b/drivers/iio/adc/ad7380.c
@@ -0,0 +1,462 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Analog Devices AD738x Simultaneous Sampling SAR ADCs
+ *
+ * Copyright 2017 Analog Devices Inc.
+ * Copyright 2023 BayLibre, SAS
+ */
+
+#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/sysfs.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.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_DIFFERENTIAL_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_DIFFERENTIAL_2_CHANNEL(name, bits) \
+static const struct iio_chan_spec name[] = { \
+ AD7380_DIFFERENTIAL_CHANNEL(0, bits), \
+ AD7380_DIFFERENTIAL_CHANNEL(1, bits), \
+ IIO_CHAN_SOFT_TIMESTAMP(2), \
+}
+
+/* fully differential */
+DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7380_channels, 16);
+DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7381_channels, 14);
+/* pseudo differential */
+DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7383_channels, 16);
+DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7384_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),
+};
+
+static const struct ad7380_chip_info ad7383_chip_info = {
+ .name = "ad7383",
+ .channels = ad7383_channels,
+ .num_channels = ARRAY_SIZE(ad7383_channels),
+};
+
+static const struct ad7380_chip_info ad7384_chip_info = {
+ .name = "ad7384",
+ .channels = ad7384_channels,
+ .num_channels = ARRAY_SIZE(ad7384_channels),
+};
+
+struct ad7380_state {
+ const struct ad7380_chip_info *chip_info;
+ struct spi_device *spi;
+ struct regulator *vref;
+ struct regmap *regmap;
+ /*
+ * 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[2];
+ u16 rx[2];
+};
+
+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[0],
+ };
+
+ st->tx[0] = 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[0],
+ .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[0],
+ },
+ };
+ int ret;
+
+ st->tx[0] = 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[0]);
+
+ return 0;
+}
+
+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)
+{
+ struct ad7380_state *st = iio_priv(indio_dev);
+ int ret;
+
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ if (readval)
+ ret = regmap_read(st->regmap, reg, readval);
+ else
+ ret = regmap_write(st->regmap, reg, writeval);
+
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+}
+
+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->rx[0],
+ .len = 4,
+ },
+ };
+ int ret;
+
+ ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers));
+ if (ret < 0)
+ return ret;
+
+ *val = sign_extend32(st->rx[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);
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ad7380_read_direct(st, chan, val);
+ iio_device_release_direct_mode(indio_dev);
+
+ return ret;
+ case IIO_CHAN_INFO_SCALE:
+ if (st->vref) {
+ ret = regulator_get_voltage(st->vref);
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
+ } else {
+ *val = AD7380_INTERNAL_REF_MV;
+ }
+
+ *val2 = chan->scan_type.realbits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ }
+
+ 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)
+{
+ 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, !!st->vref));
+ 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;
+ 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");
+
+ st->vref = devm_regulator_get_optional(&spi->dev, "refio");
+ if (IS_ERR(st->vref)) {
+ /*
+ * If there is no REFIO supply, then it means that we are using
+ * the internal 2.5V reference.
+ */
+ if (PTR_ERR(st->vref) == -ENODEV)
+ st->vref = NULL;
+ else
+ return dev_err_probe(&spi->dev, PTR_ERR(st->vref),
+ "Failed to get refio regulator\n");
+ }
+
+ if (st->vref) {
+ ret = regulator_enable(st->vref);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(&spi->dev, ad7380_regulator_disable,
+ st->vref);
+ if (ret)
+ return ret;
+ }
+
+ 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);
+ 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 },
+ { .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);
+
+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 <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD738x ADC driver");
+MODULE_LICENSE("GPL");
--
2.43.0
On Wed, Jan 10, 2024 at 02:28:40PM -0600, David Lechner wrote:
> This adds a binding specification for the Analog Devices Inc. AD7380
> family of ADCs.
>
> Signed-off-by: David Lechner <[email protected]>
> ---
>
> As discussed in [1], the proposed spi-rx-bus-channels property is a complex
> new SPI core feature, so it was nacked for now on the grounds that it should
> be accepted without the corresponding SPI core changes. I dropped the Reviewed-by
> since no DT maintainers responded on that thread.
I think that's reasonable. Better to wait and do something correct when
the problme is understood than rush into something. You can re-add
Reviewed-by: Conor Dooley <[email protected]>
Cheers,
Conor.
On Wed, 10 Jan 2024 14:28:39 -0600
David Lechner <[email protected]> wrote:
> 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.
>
> One quirk of these chips is that since they are simultaneous sampling,
> they have multiple SPI data output lines that allow transferring two
> data words (one for each input channel) at the same time. So a new
> generic devicetree binding is added to describe this sort of SPI bus
> configuration.
>
> To keep things simple, the initial driver implementation only supports
> the 2-channel differential chips listed above. There are also 4-channel
> differential chips and 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.
>
> Also, FYI, this driver will also be used as the base for an upcoming
> series adding AXI SPI Engine offload support for these chips along with
> [1].
>
> This work is being done by BayLibre and on behalf of Analog Devices Inc.
> hence the maintainers are @analog.com.
>
> [1]: https://lore.kernel.org/linux-spi/[email protected]/
Series applied to the togreg branch of iio.git though that is only pushed
out as testing for now as I'll be rebasing it on rc1 once available.
Jonathan
On Wed, Jan 10, 2024 at 2:29 PM David Lechner <[email protected]> wrote:
>
> This adds a new driver for the AD7380 family ADCs.
>
> The driver currently implements basic support for the AD7380, AD7381,
> AD7383, and AD7384 2-channel differential ADCs. Support for additional
> single-ended and 4-channel chips that use the same register map as well
> as additional features of the chip will be added in future patches.
>
Hi Jonathan,
We have some additional features to add to this driver we are working
on that look like they might affect userspace. Can we hold off on
sending this one to Greg for 6.9? That way we will have more time to
sort that out without having to worry about breaking userspace.
On Fri, 16 Feb 2024 14:34:01 -0600
David Lechner <[email protected]> wrote:
> On Wed, Jan 10, 2024 at 2:29 PM David Lechner <[email protected]> wrote:
> >
> > This adds a new driver for the AD7380 family ADCs.
> >
> > The driver currently implements basic support for the AD7380, AD7381,
> > AD7383, and AD7384 2-channel differential ADCs. Support for additional
> > single-ended and 4-channel chips that use the same register map as well
> > as additional features of the chip will be added in future patches.
> >
>
> Hi Jonathan,
>
> We have some additional features to add to this driver we are working
> on that look like they might affect userspace. Can we hold off on
> sending this one to Greg for 6.9? That way we will have more time to
> sort that out without having to worry about breaking userspace.
Ok. Hopefully rebasing my tree won't cause others too many downstream
problems. Generally I only do this if there is an invalid tag or similar
that must be fixed. There is normally a window of a weekish
between me picking it up and pushing out for linux-next to pick up and
hopefully issues like this get spotted in that window.
Ah well, sometimes things don't work out how we would like them to.
Dropped the 3 patches (original driver and a fix) from the togreg branch.
Jonathan
On 2/17/24 10:20 AM, Jonathan Cameron wrote:
> On Fri, 16 Feb 2024 14:34:01 -0600
> David Lechner <[email protected]> wrote:
>
>> On Wed, Jan 10, 2024 at 2:29 PM David Lechner <[email protected]> wrote:
>>>
>>> This adds a new driver for the AD7380 family ADCs.
>>>
>>> The driver currently implements basic support for the AD7380, AD7381,
>>> AD7383, and AD7384 2-channel differential ADCs. Support for additional
>>> single-ended and 4-channel chips that use the same register map as well
>>> as additional features of the chip will be added in future patches.
>>>
>>
>> Hi Jonathan,
>>
>> We have some additional features to add to this driver we are working
>> on that look like they might affect userspace. Can we hold off on
>> sending this one to Greg for 6.9? That way we will have more time to
>> sort that out without having to worry about breaking userspace.
>
> Ok. Hopefully rebasing my tree won't cause others too many downstream
> problems. Generally I only do this if there is an invalid tag or similar
> that must be fixed. There is normally a window of a weekish
> between me picking it up and pushing out for linux-next to pick up and
> hopefully issues like this get spotted in that window.
> Ah well, sometimes things don't work out how we would like them to.
>
> Dropped the 3 patches (original driver and a fix) from the togreg branch.
>
Thanks. I will keep the the one week window in mind if we have similar cases in the future.
On Wed, Jan 10, 2024 at 2:29 PM David Lechner <[email protected]> wrote:
..
> +
> +/* fully differential */
> +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7380_channels, 16);
> +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7381_channels, 14);
> +/* pseudo differential */
> +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7383_channels, 16);
> +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7384_channels, 14);
> +
Similar question to [1] in light of [2]: Since AD7383 and AD7384 are
pseudo-differential, should we handle them differently? I.e. add
aina-supply and ainb-supply DT properties for the negative inputs
(typically a V_REF / 2 supply) and remove the differential flag from
the channel spec.
[1]: https://lore.kernel.org/linux-iio/CAMknhBH2Pqa9xpPxnTCxJegVTbOG-QDeJA4YrQUPfj+hfSs73A@mail.gmail.com/
[2]: https://lore.kernel.org/linux-iio/CAMknhBF5mAsN1c-194Qwa5oKmqKzef2khXnqA1cSdKpWHKWp0w@mail.gmail.com/
On Mon, 19 Feb 2024 13:47:03 -0600
David Lechner <[email protected]> wrote:
> On Wed, Jan 10, 2024 at 2:29 PM David Lechner <[email protected]> wrote:
>
> ...
>
> > +
> > +/* fully differential */
> > +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7380_channels, 16);
> > +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7381_channels, 14);
> > +/* pseudo differential */
> > +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7383_channels, 16);
> > +DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL(ad7384_channels, 14);
> > +
>
> Similar question to [1] in light of [2]: Since AD7383 and AD7384 are
> pseudo-differential, should we handle them differently? I.e. add
> aina-supply and ainb-supply DT properties for the negative inputs
> (typically a V_REF / 2 supply) and remove the differential flag from
> the channel spec.
>
> [1]: https://lore.kernel.org/linux-iio/CAMknhBH2Pqa9xpPxnTCxJegVTbOG-QDeJA4YrQUPfj+hfSs73A@mail.gmail.com/
> [2]: https://lore.kernel.org/linux-iio/CAMknhBF5mAsN1c-194Qwa5oKmqKzef2khXnqA1cSdKpWHKWp0w@mail.gmail.com/
Yes. I think that gives a more intuitive interface for users.
I don't think we need to 'fix' any drivers already upstream as
presenting these as differential is not an ABI error as far as I
am concerned. It's just less than ideal choices given our views
now! (as a result of these discussions on what pseudo differential
means in practice)
Jonathan