This patchset adds a basic driver for the AD7292 ADC/DAC system along
with devicetree binding documentation.
Changelog V3:
- dt-binding: changed spi-cpha property
- dt-binding: added spi-cpha to the list of required properties
- dt-binding: renamed example device node
- dt-binding: added ';' to the final curly braces correctly closing dt-schema
- ad7292: fix up a typo in channel macros
Marcelo Schmitt (2):
dt-bindings: iio: adc: Add dt-schema for AD7292
iio: adc: Add driver support for AD7292
.../bindings/iio/adc/adi,ad7292.yaml | 103 ++++++
MAINTAINERS | 8 +
drivers/iio/adc/Kconfig | 10 +
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7292.c | 350 ++++++++++++++++++
5 files changed, 472 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
create mode 100644 drivers/iio/adc/ad7292.c
--
2.23.0
Add a devicetree schema for AD7292 monitor and control system.
Signed-off-by: Marcelo Schmitt <[email protected]>
---
Changelog V2 -> V3:
- changed spi-cpha property
- added spi-cpha to the list of required properties
- renamed example device node
- added ';' to the final curly braces correctly closing dt-schema
.../bindings/iio/adc/adi,ad7292.yaml | 103 ++++++++++++++++++
MAINTAINERS | 7 ++
2 files changed, 110 insertions(+)
create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
new file mode 100644
index 000000000000..1014eb50a263
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Analog Devices AD7292 10-Bit Monitor and Control System
+
+maintainers:
+ - Marcelo Schmitt <[email protected]>
+
+description: |
+ Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs,
+ Temperature Sensor, and GPIOs
+
+ Specifications about the part can be found at:
+ https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
+
+properties:
+ compatible:
+ enum:
+ - adi,ad7292
+
+ reg:
+ maxItems: 1
+
+ vref-supply:
+ description: |
+ The regulator supply for ADC and DAC reference voltage.
+
+ spi-cpha: true
+
+ '#address-cells':
+ const: 1
+
+ '#size-cells':
+ const: 0
+
+required:
+ - compatible
+ - reg
+ - spi-cpha
+
+patternProperties:
+ "^channel@[0-7]$":
+ type: object
+ description: |
+ Represents the external channels which are connected to the ADC.
+ See Documentation/devicetree/bindings/iio/adc/adc.txt.
+
+ properties:
+ reg:
+ description: |
+ The channel number. It can have up to 8 channels numbered from 0 to 7.
+ maxItems: 1
+
+ diff-channels:
+ description: see Documentation/devicetree/bindings/iio/adc/adc.txt
+ maxItems: 1
+
+ required:
+ - reg
+
+examples:
+ - |
+ spi {
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ ad7292: adc@0 {
+ compatible = "adi,ad7292";
+ reg = <0>;
+ spi-max-frequency = <25000000>;
+ vref-supply = <&adc_vref>;
+ spi-cpha;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ channel@0 {
+ reg = <0>;
+ diff-channels = <0 1>;
+ };
+ channel@2 {
+ reg = <2>;
+ };
+ channel@3 {
+ reg = <3>;
+ };
+ channel@4 {
+ reg = <4>;
+ };
+ channel@5 {
+ reg = <5>;
+ };
+ channel@6 {
+ reg = <6>;
+ };
+ channel@7 {
+ reg = <7>;
+ };
+ };
+ };
diff --git a/MAINTAINERS b/MAINTAINERS
index 32bf5f8116d0..5d00e871c4c6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -813,6 +813,13 @@ S: Supported
F: drivers/iio/adc/ad7124.c
F: Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
+ANALOG DEVICES INC AD7292 DRIVER
+M: Marcelo Schmitt <[email protected]>
+L: [email protected]
+W: http://ez.analog.com/community/linux-device-drivers
+S: Supported
+F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
+
ANALOG DEVICES INC AD7606 DRIVER
M: Stefan Popa <[email protected]>
L: [email protected]
--
2.23.0
The AD7292 is a 10-bit monitor and control system with ADC, DACs,
temperature sensor, and GPIOs.
Configure AD7292 devices in direct access mode, enabling single-ended
ADC readings.
Datasheet:
Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
Signed-off-by: Marcelo Schmitt <[email protected]>
---
Changelog V2 -> V3:
- fix up a typo in channel macros
MAINTAINERS | 1 +
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
4 files changed, 362 insertions(+)
create mode 100644 drivers/iio/adc/ad7292.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 5d00e871c4c6..5941cfc0d6f7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -818,6 +818,7 @@ M: Marcelo Schmitt <[email protected]>
L: [email protected]
W: http://ez.analog.com/community/linux-device-drivers
S: Supported
+F: drivers/iio/adc/ad7292.c
F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
ANALOG DEVICES INC AD7606 DRIVER
diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
index 632b331429c6..02587c990cb5 100644
--- a/drivers/iio/adc/Kconfig
+++ b/drivers/iio/adc/Kconfig
@@ -59,6 +59,16 @@ config AD7291
To compile this driver as a module, choose M here: the
module will be called ad7291.
+config AD7292
+ tristate "Analog Devices AD7292 ADC driver"
+ depends on SPI
+ help
+ Say yes here to build support for Analog Devices AD7292
+ 8 Channel ADC with temperature sensor.
+
+ To compile this driver as a module, choose M here: the
+ module will be called ad7292.
+
config AD7298
tristate "Analog Devices AD7298 ADC driver"
depends on SPI
diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
index 4779ab3ff8fb..1818f2f66566 100644
--- a/drivers/iio/adc/Makefile
+++ b/drivers/iio/adc/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o
obj-$(CONFIG_AD7173) += ad7173.o
obj-$(CONFIG_AD7266) += ad7266.o
obj-$(CONFIG_AD7291) += ad7291.o
+obj-$(CONFIG_AD7292) += ad7292.o
obj-$(CONFIG_AD7298) += ad7298.o
obj-$(CONFIG_AD738X) += ad738x.o
obj-$(CONFIG_AD7768) += ad7768-1.o
diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c
new file mode 100644
index 000000000000..e2badf6ac10d
--- /dev/null
+++ b/drivers/iio/adc/ad7292.c
@@ -0,0 +1,350 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices AD7292 SPI ADC driver
+ *
+ * Copyright 2019 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/iio.h>
+
+#define ADI_VENDOR_ID 0x0018
+
+/* AD7292 registers definition */
+#define AD7292_REG_VENDOR_ID 0x00
+#define AD7292_REG_CONF_BANK 0x05
+#define AD7292_REG_CONV_COMM 0x0E
+#define AD7292_REG_ADC_CH(x) (0x10 + (x))
+
+/* AD7292 configuration bank subregisters definition */
+#define AD7292_BANK_REG_VIN_RNG0 0x10
+#define AD7292_BANK_REG_VIN_RNG1 0x11
+#define AD7292_BANK_REG_SAMP_MODE 0x12
+
+#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F))
+
+/* AD7292_REG_ADC_CONVERSION */
+#define AD7292_ADC_DATA_MASK GENMASK(15, 6)
+#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x)
+
+/* AD7292_CHANNEL_SAMPLING_MODE */
+#define AD7292_CH_SAMP_MODE(reg, ch) ((reg >> 8) & BIT(ch))
+
+/* AD7292_CHANNEL_VIN_RANGE */
+#define AD7292_CH_VIN_RANGE(reg, ch) (reg & BIT(ch))
+
+#define AD7292_VOLTAGE_CHAN(_chan) \
+{ \
+ .type = IIO_VOLTAGE, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
+ BIT(IIO_CHAN_INFO_SCALE), \
+ .indexed = 1, \
+ .channel = _chan, \
+}
+
+static const struct iio_chan_spec ad7292_channels[] = {
+ AD7292_VOLTAGE_CHAN(0),
+ AD7292_VOLTAGE_CHAN(1),
+ AD7292_VOLTAGE_CHAN(2),
+ AD7292_VOLTAGE_CHAN(3),
+ AD7292_VOLTAGE_CHAN(4),
+ AD7292_VOLTAGE_CHAN(5),
+ AD7292_VOLTAGE_CHAN(6),
+ AD7292_VOLTAGE_CHAN(7)
+};
+
+static const struct iio_chan_spec ad7292_channels_diff[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .indexed = 1,
+ .differential = 1,
+ .channel = 0,
+ .channel2 = 1,
+ },
+ AD7292_VOLTAGE_CHAN(2),
+ AD7292_VOLTAGE_CHAN(3),
+ AD7292_VOLTAGE_CHAN(4),
+ AD7292_VOLTAGE_CHAN(5),
+ AD7292_VOLTAGE_CHAN(6),
+ AD7292_VOLTAGE_CHAN(7)
+};
+
+struct ad7292_state {
+ struct spi_device *spi;
+ struct regulator *reg;
+ unsigned short vref_mv;
+
+ __be16 d16 ____cacheline_aligned;
+ u8 d8[2];
+};
+
+static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
+{
+ int ret;
+
+ st->d8[0] = AD7292_RD_FLAG_MSK(addr);
+
+ ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);
+ if (ret < 0)
+ return ret;
+
+ return be16_to_cpu(st->d16);
+}
+
+static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,
+ unsigned int sub_addr, unsigned int len)
+{
+ unsigned int shift = 16 - (8 * len);
+ int ret;
+
+ st->d8[0] = AD7292_RD_FLAG_MSK(addr);
+ st->d8[1] = sub_addr;
+
+ ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);
+ if (ret < 0)
+ return ret;
+
+ return (be16_to_cpu(st->d16) >> shift);
+}
+
+static int ad7292_single_conversion(struct ad7292_state *st,
+ unsigned int chan_addr)
+{
+ int ret;
+
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = &st->d8,
+ .len = 4,
+ .delay_usecs = 6,
+ }, {
+ .rx_buf = &st->d16,
+ .len = 2,
+ },
+ };
+
+ st->d8[0] = chan_addr;
+ st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);
+
+ ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+
+ if (ret < 0)
+ return ret;
+
+ return be16_to_cpu(st->d16);
+}
+
+static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
+{
+ int samp_mode, range0, range1, factor = 1;
+
+ /*
+ * Every AD7292 ADC channel may have its input range adjusted according
+ * to the settings at the ADC sampling mode and VIN range subregisters.
+ * For a given channel, the minimum input range is equal to Vref, and it
+ * may be increased by a multiplier factor of 2 or 4 according to the
+ * following rule:
+ * If channel is being sampled with respect to AGND:
+ * factor = 4 if VIN range0 and VIN range1 equal 0
+ * factor = 2 if only one of VIN ranges equal 1
+ * factor = 1 if both VIN range0 and VIN range1 equal 1
+ * If channel is being sampled with respect to AVDD:
+ * factor = 4 if VIN range0 and VIN range1 equal 0
+ * Behavior is undefined if any of VIN range doesn't equal 0
+ */
+
+ samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+ AD7292_BANK_REG_SAMP_MODE, 2);
+
+ if (samp_mode < 0)
+ return samp_mode;
+
+ range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+ AD7292_BANK_REG_VIN_RNG0, 2);
+
+ if (range0 < 0)
+ return range0;
+
+ range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
+ AD7292_BANK_REG_VIN_RNG1, 2);
+
+ if (range1 < 0)
+ return range1;
+
+ if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {
+ /* Sampling with respect to AGND */
+ if (!AD7292_CH_VIN_RANGE(range0, channel))
+ factor *= 2;
+
+ if (!AD7292_CH_VIN_RANGE(range1, channel))
+ factor *= 2;
+
+ } else {
+ /* Sampling with respect to AVDD */
+ if (AD7292_CH_VIN_RANGE(range0, channel) ||
+ AD7292_CH_VIN_RANGE(range1, channel))
+ return -EPERM;
+
+ factor = 4;
+ }
+
+ return factor;
+}
+
+static int ad7292_read_raw(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan,
+ int *val, int *val2, long info)
+{
+ struct ad7292_state *st = iio_priv(indio_dev);
+ unsigned int ch_addr;
+ int ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ ch_addr = AD7292_REG_ADC_CH(chan->channel);
+ ret = ad7292_single_conversion(st, ch_addr);
+ if (ret < 0)
+ return ret;
+
+ *val = AD7292_ADC_DATA(ret);
+
+ return IIO_VAL_INT;
+ case IIO_CHAN_INFO_SCALE:
+ /*
+ * To convert a raw value to standard units, the IIO defines
+ * this formula: Scaled value = (raw + offset) * scale.
+ * For the scale to be a correct multiplier for (raw + offset),
+ * it must be calculated as the input range divided by the
+ * number of possible distinct input values. Given the ADC data
+ * is 10 bit long, it may assume 2^10 distinct values.
+ * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2
+ * return type indicates to the IIO API to divide *val by 2 to
+ * the power of *val2 when returning from read_raw.
+ */
+
+ ret = ad7292_vin_range_multiplier(st, chan->channel);
+ if (ret < 0)
+ return ret;
+
+ *val = st->vref_mv * ret;
+ *val2 = 10;
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ break;
+ }
+ return -EINVAL;
+}
+
+static const struct iio_info ad7292_info = {
+ .read_raw = ad7292_read_raw,
+};
+
+static void ad7292_regulator_disable(void *data)
+{
+ struct ad7292_state *st = data;
+
+ regulator_disable(st->reg);
+}
+
+static int ad7292_probe(struct spi_device *spi)
+{
+ struct ad7292_state *st;
+ struct iio_dev *indio_dev;
+ struct device_node *child;
+ bool diff_channels = 0;
+ 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;
+
+ ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);
+ if (ret != ADI_VENDOR_ID) {
+ dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);
+ return -EINVAL;
+ }
+
+ spi_set_drvdata(spi, indio_dev);
+
+ st->reg = devm_regulator_get_optional(&spi->dev, "vref");
+ if (!IS_ERR(st->reg)) {
+ ret = regulator_enable(st->reg);
+ if (ret) {
+ dev_err(&spi->dev,
+ "Failed to enable external vref supply\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(&spi->dev,
+ ad7292_regulator_disable, st);
+ if (ret) {
+ regulator_disable(st->reg);
+ return ret;
+ }
+
+ ret = regulator_get_voltage(st->reg);
+ if (ret < 0)
+ return ret;
+
+ st->vref_mv = ret / 1000;
+ } else {
+ /* Use the internal voltage reference. */
+ st->vref_mv = 1250;
+ }
+
+ indio_dev->dev.parent = &spi->dev;
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &ad7292_info;
+
+ for_each_available_child_of_node(spi->dev.of_node, child) {
+ diff_channels = of_property_read_bool(child, "diff-channels");
+ if (diff_channels)
+ break;
+ }
+
+ if (diff_channels) {
+ indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);
+ indio_dev->channels = ad7292_channels_diff;
+ } else {
+ indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);
+ indio_dev->channels = ad7292_channels;
+ }
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad7292_id_table[] = {
+ { "ad7292", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad7292_id_table);
+
+static const struct of_device_id ad7292_of_match[] = {
+ { .compatible = "adi,ad7292" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ad7292_of_match);
+
+static struct spi_driver ad7292_driver = {
+ .driver = {
+ .name = "ad7292",
+ .of_match_table = ad7292_of_match,
+ },
+ .probe = ad7292_probe,
+ .id_table = ad7292_id_table,
+};
+module_spi_driver(ad7292_driver);
+
+MODULE_AUTHOR("Marcelo Schmitt <[email protected]>");
+MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");
+MODULE_LICENSE("GPL v2");
--
2.23.0
On Fri, 1 Nov 2019 13:24:26 -0300
Marcelo Schmitt <[email protected]> wrote:
> The AD7292 is a 10-bit monitor and control system with ADC, DACs,
> temperature sensor, and GPIOs.
>
> Configure AD7292 devices in direct access mode, enabling single-ended
> ADC readings.
>
> Datasheet:
> Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
>
> Signed-off-by: Marcelo Schmitt <[email protected]>
One totally trivial thing inline if you happen to be respinning.
Otherwise I'll fix up when applying.
I would like to give a bit of time for others to comment, particularly on the dt
bindings as I frequently miss problems in them. Hence I won't be applying it today
but may pick it up later in the week or next weekend.
Thanks,
Jonathan
> ---
> Changelog V2 -> V3:
> - fix up a typo in channel macros
>
> MAINTAINERS | 1 +
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 362 insertions(+)
> create mode 100644 drivers/iio/adc/ad7292.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 5d00e871c4c6..5941cfc0d6f7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -818,6 +818,7 @@ M: Marcelo Schmitt <[email protected]>
> L: [email protected]
> W: http://ez.analog.com/community/linux-device-drivers
> S: Supported
> +F: drivers/iio/adc/ad7292.c
> F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
>
> ANALOG DEVICES INC AD7606 DRIVER
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 632b331429c6..02587c990cb5 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -59,6 +59,16 @@ config AD7291
> To compile this driver as a module, choose M here: the
> module will be called ad7291.
>
> +config AD7292
> + tristate "Analog Devices AD7292 ADC driver"
> + depends on SPI
> + help
> + Say yes here to build support for Analog Devices AD7292
> + 8 Channel ADC with temperature sensor.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad7292.
> +
> config AD7298
> tristate "Analog Devices AD7298 ADC driver"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 4779ab3ff8fb..1818f2f66566 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o
> obj-$(CONFIG_AD7173) += ad7173.o
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AD7291) += ad7291.o
> +obj-$(CONFIG_AD7292) += ad7292.o
> obj-$(CONFIG_AD7298) += ad7298.o
> obj-$(CONFIG_AD738X) += ad738x.o
> obj-$(CONFIG_AD7768) += ad7768-1.o
> diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c
> new file mode 100644
> index 000000000000..e2badf6ac10d
> --- /dev/null
> +++ b/drivers/iio/adc/ad7292.c
> @@ -0,0 +1,350 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Analog Devices AD7292 SPI ADC driver
> + *
> + * Copyright 2019 Analog Devices Inc.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +
> +#include <linux/iio/iio.h>
> +
> +#define ADI_VENDOR_ID 0x0018
> +
> +/* AD7292 registers definition */
> +#define AD7292_REG_VENDOR_ID 0x00
> +#define AD7292_REG_CONF_BANK 0x05
> +#define AD7292_REG_CONV_COMM 0x0E
> +#define AD7292_REG_ADC_CH(x) (0x10 + (x))
> +
> +/* AD7292 configuration bank subregisters definition */
> +#define AD7292_BANK_REG_VIN_RNG0 0x10
> +#define AD7292_BANK_REG_VIN_RNG1 0x11
> +#define AD7292_BANK_REG_SAMP_MODE 0x12
> +
> +#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F))
> +
> +/* AD7292_REG_ADC_CONVERSION */
> +#define AD7292_ADC_DATA_MASK GENMASK(15, 6)
> +#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x)
> +
> +/* AD7292_CHANNEL_SAMPLING_MODE */
> +#define AD7292_CH_SAMP_MODE(reg, ch) ((reg >> 8) & BIT(ch))
> +
> +/* AD7292_CHANNEL_VIN_RANGE */
> +#define AD7292_CH_VIN_RANGE(reg, ch) (reg & BIT(ch))
Trivial but all macro parameters should be in brackets to prevent
weirdness if some sticks a parameter with higher precedence in there
so ((reg) & BIT(ch)).
I can fix this up if the rest is fine.
> +
> +#define AD7292_VOLTAGE_CHAN(_chan) \
> +{ \
> + .type = IIO_VOLTAGE, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> + BIT(IIO_CHAN_INFO_SCALE), \
> + .indexed = 1, \
> + .channel = _chan, \
> +}
> +
> +static const struct iio_chan_spec ad7292_channels[] = {
> + AD7292_VOLTAGE_CHAN(0),
> + AD7292_VOLTAGE_CHAN(1),
> + AD7292_VOLTAGE_CHAN(2),
> + AD7292_VOLTAGE_CHAN(3),
> + AD7292_VOLTAGE_CHAN(4),
> + AD7292_VOLTAGE_CHAN(5),
> + AD7292_VOLTAGE_CHAN(6),
> + AD7292_VOLTAGE_CHAN(7)
> +};
> +
> +static const struct iio_chan_spec ad7292_channels_diff[] = {
> + {
> + .type = IIO_VOLTAGE,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> + .indexed = 1,
> + .differential = 1,
> + .channel = 0,
> + .channel2 = 1,
> + },
> + AD7292_VOLTAGE_CHAN(2),
> + AD7292_VOLTAGE_CHAN(3),
> + AD7292_VOLTAGE_CHAN(4),
> + AD7292_VOLTAGE_CHAN(5),
> + AD7292_VOLTAGE_CHAN(6),
> + AD7292_VOLTAGE_CHAN(7)
> +};
> +
> +struct ad7292_state {
> + struct spi_device *spi;
> + struct regulator *reg;
> + unsigned short vref_mv;
> +
> + __be16 d16 ____cacheline_aligned;
> + u8 d8[2];
> +};
> +
> +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
> +{
> + int ret;
> +
> + st->d8[0] = AD7292_RD_FLAG_MSK(addr);
> +
> + ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);
> + if (ret < 0)
> + return ret;
> +
> + return be16_to_cpu(st->d16);
> +}
> +
> +static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,
> + unsigned int sub_addr, unsigned int len)
> +{
> + unsigned int shift = 16 - (8 * len);
> + int ret;
> +
> + st->d8[0] = AD7292_RD_FLAG_MSK(addr);
> + st->d8[1] = sub_addr;
> +
> + ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);
> + if (ret < 0)
> + return ret;
> +
> + return (be16_to_cpu(st->d16) >> shift);
> +}
> +
> +static int ad7292_single_conversion(struct ad7292_state *st,
> + unsigned int chan_addr)
> +{
> + int ret;
> +
> + struct spi_transfer t[] = {
> + {
> + .tx_buf = &st->d8,
> + .len = 4,
> + .delay_usecs = 6,
> + }, {
> + .rx_buf = &st->d16,
> + .len = 2,
> + },
> + };
> +
> + st->d8[0] = chan_addr;
> + st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);
> +
> + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
> +
> + if (ret < 0)
> + return ret;
> +
> + return be16_to_cpu(st->d16);
> +}
> +
> +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
> +{
> + int samp_mode, range0, range1, factor = 1;
> +
> + /*
> + * Every AD7292 ADC channel may have its input range adjusted according
> + * to the settings at the ADC sampling mode and VIN range subregisters.
> + * For a given channel, the minimum input range is equal to Vref, and it
> + * may be increased by a multiplier factor of 2 or 4 according to the
> + * following rule:
> + * If channel is being sampled with respect to AGND:
> + * factor = 4 if VIN range0 and VIN range1 equal 0
> + * factor = 2 if only one of VIN ranges equal 1
> + * factor = 1 if both VIN range0 and VIN range1 equal 1
> + * If channel is being sampled with respect to AVDD:
> + * factor = 4 if VIN range0 and VIN range1 equal 0
> + * Behavior is undefined if any of VIN range doesn't equal 0
> + */
> +
> + samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> + AD7292_BANK_REG_SAMP_MODE, 2);
> +
> + if (samp_mode < 0)
> + return samp_mode;
> +
> + range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> + AD7292_BANK_REG_VIN_RNG0, 2);
> +
> + if (range0 < 0)
> + return range0;
> +
> + range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> + AD7292_BANK_REG_VIN_RNG1, 2);
> +
> + if (range1 < 0)
> + return range1;
> +
> + if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {
> + /* Sampling with respect to AGND */
> + if (!AD7292_CH_VIN_RANGE(range0, channel))
> + factor *= 2;
> +
> + if (!AD7292_CH_VIN_RANGE(range1, channel))
> + factor *= 2;
> +
> + } else {
> + /* Sampling with respect to AVDD */
> + if (AD7292_CH_VIN_RANGE(range0, channel) ||
> + AD7292_CH_VIN_RANGE(range1, channel))
> + return -EPERM;
> +
> + factor = 4;
> + }
> +
> + return factor;
> +}
> +
> +static int ad7292_read_raw(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + int *val, int *val2, long info)
> +{
> + struct ad7292_state *st = iio_priv(indio_dev);
> + unsigned int ch_addr;
> + int ret;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + ch_addr = AD7292_REG_ADC_CH(chan->channel);
> + ret = ad7292_single_conversion(st, ch_addr);
> + if (ret < 0)
> + return ret;
> +
> + *val = AD7292_ADC_DATA(ret);
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + /*
> + * To convert a raw value to standard units, the IIO defines
> + * this formula: Scaled value = (raw + offset) * scale.
> + * For the scale to be a correct multiplier for (raw + offset),
> + * it must be calculated as the input range divided by the
> + * number of possible distinct input values. Given the ADC data
> + * is 10 bit long, it may assume 2^10 distinct values.
> + * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2
> + * return type indicates to the IIO API to divide *val by 2 to
> + * the power of *val2 when returning from read_raw.
> + */
> +
> + ret = ad7292_vin_range_multiplier(st, chan->channel);
> + if (ret < 0)
> + return ret;
> +
> + *val = st->vref_mv * ret;
> + *val2 = 10;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + default:
> + break;
> + }
> + return -EINVAL;
> +}
> +
> +static const struct iio_info ad7292_info = {
> + .read_raw = ad7292_read_raw,
> +};
> +
> +static void ad7292_regulator_disable(void *data)
> +{
> + struct ad7292_state *st = data;
> +
> + regulator_disable(st->reg);
> +}
> +
> +static int ad7292_probe(struct spi_device *spi)
> +{
> + struct ad7292_state *st;
> + struct iio_dev *indio_dev;
> + struct device_node *child;
> + bool diff_channels = 0;
> + 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;
> +
> + ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);
> + if (ret != ADI_VENDOR_ID) {
> + dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);
> + return -EINVAL;
> + }
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + st->reg = devm_regulator_get_optional(&spi->dev, "vref");
> + if (!IS_ERR(st->reg)) {
> + ret = regulator_enable(st->reg);
> + if (ret) {
> + dev_err(&spi->dev,
> + "Failed to enable external vref supply\n");
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(&spi->dev,
> + ad7292_regulator_disable, st);
> + if (ret) {
> + regulator_disable(st->reg);
> + return ret;
> + }
> +
> + ret = regulator_get_voltage(st->reg);
> + if (ret < 0)
> + return ret;
> +
> + st->vref_mv = ret / 1000;
> + } else {
> + /* Use the internal voltage reference. */
> + st->vref_mv = 1250;
> + }
> +
> + indio_dev->dev.parent = &spi->dev;
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ad7292_info;
> +
> + for_each_available_child_of_node(spi->dev.of_node, child) {
> + diff_channels = of_property_read_bool(child, "diff-channels");
> + if (diff_channels)
> + break;
> + }
> +
> + if (diff_channels) {
> + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);
> + indio_dev->channels = ad7292_channels_diff;
> + } else {
> + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);
> + indio_dev->channels = ad7292_channels;
> + }
> +
> + return devm_iio_device_register(&spi->dev, indio_dev);
> +}
> +
> +static const struct spi_device_id ad7292_id_table[] = {
> + { "ad7292", 0 },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, ad7292_id_table);
> +
> +static const struct of_device_id ad7292_of_match[] = {
> + { .compatible = "adi,ad7292" },
> + { },
> +};
> +MODULE_DEVICE_TABLE(of, ad7292_of_match);
> +
> +static struct spi_driver ad7292_driver = {
> + .driver = {
> + .name = "ad7292",
> + .of_match_table = ad7292_of_match,
> + },
> + .probe = ad7292_probe,
> + .id_table = ad7292_id_table,
> +};
> +module_spi_driver(ad7292_driver);
> +
> +MODULE_AUTHOR("Marcelo Schmitt <[email protected]>");
> +MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");
> +MODULE_LICENSE("GPL v2");
On Fri, Nov 01, 2019 at 01:23:59PM -0300, Marcelo Schmitt wrote:
> Add a devicetree schema for AD7292 monitor and control system.
>
> Signed-off-by: Marcelo Schmitt <[email protected]>
> ---
> Changelog V2 -> V3:
> - changed spi-cpha property
> - added spi-cpha to the list of required properties
> - renamed example device node
> - added ';' to the final curly braces correctly closing dt-schema
>
> .../bindings/iio/adc/adi,ad7292.yaml | 103 ++++++++++++++++++
> MAINTAINERS | 7 ++
> 2 files changed, 110 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
>
> diff --git a/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> new file mode 100644
> index 000000000000..1014eb50a263
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> @@ -0,0 +1,103 @@
> +# SPDX-License-Identifier: GPL-2.0
For new bindings:
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/adi,ad7292.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Analog Devices AD7292 10-Bit Monitor and Control System
> +
> +maintainers:
> + - Marcelo Schmitt <[email protected]>
> +
> +description: |
> + Analog Devices AD7292 10-Bit Monitor and Control System with ADC, DACs,
> + Temperature Sensor, and GPIOs
> +
> + Specifications about the part can be found at:
> + https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
> +
> +properties:
> + compatible:
> + enum:
> + - adi,ad7292
> +
> + reg:
> + maxItems: 1
> +
> + vref-supply:
> + description: |
> + The regulator supply for ADC and DAC reference voltage.
> +
> + spi-cpha: true
> +
> + '#address-cells':
> + const: 1
> +
> + '#size-cells':
> + const: 0
> +
> +required:
> + - compatible
> + - reg
> + - spi-cpha
> +
> +patternProperties:
> + "^channel@[0-7]$":
> + type: object
> + description: |
> + Represents the external channels which are connected to the ADC.
> + See Documentation/devicetree/bindings/iio/adc/adc.txt.
> +
> + properties:
> + reg:
> + description: |
> + The channel number. It can have up to 8 channels numbered from 0 to 7.
Can be a constraint:
items:
- maximum: 7
> + maxItems: 1
And then drop this because it's implied by the above.
> +
> + diff-channels:
> + description: see Documentation/devicetree/bindings/iio/adc/adc.txt
> + maxItems: 1
> +
> + required:
> + - reg
> +
> +examples:
> + - |
> + spi {
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + ad7292: adc@0 {
> + compatible = "adi,ad7292";
> + reg = <0>;
> + spi-max-frequency = <25000000>;
> + vref-supply = <&adc_vref>;
> + spi-cpha;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + channel@0 {
> + reg = <0>;
> + diff-channels = <0 1>;
> + };
> + channel@2 {
> + reg = <2>;
> + };
> + channel@3 {
> + reg = <3>;
> + };
> + channel@4 {
> + reg = <4>;
> + };
> + channel@5 {
> + reg = <5>;
> + };
> + channel@6 {
> + reg = <6>;
> + };
> + channel@7 {
> + reg = <7>;
> + };
> + };
> + };
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 32bf5f8116d0..5d00e871c4c6 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -813,6 +813,13 @@ S: Supported
> F: drivers/iio/adc/ad7124.c
> F: Documentation/devicetree/bindings/iio/adc/adi,ad7124.txt
>
> +ANALOG DEVICES INC AD7292 DRIVER
> +M: Marcelo Schmitt <[email protected]>
> +L: [email protected]
> +W: http://ez.analog.com/community/linux-device-drivers
> +S: Supported
> +F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> +
> ANALOG DEVICES INC AD7606 DRIVER
> M: Stefan Popa <[email protected]>
> L: [email protected]
> --
> 2.23.0
>
Hi,
I'll respin for the dt-schema. Thus, I can add brackets to macro
parameters. I think I found another couple of brackets missing.
Comments inline.
Thanks,
Marcelo
On 11/03, Jonathan Cameron wrote:
> On Fri, 1 Nov 2019 13:24:26 -0300
> Marcelo Schmitt <[email protected]> wrote:
>
> > The AD7292 is a 10-bit monitor and control system with ADC, DACs,
> > temperature sensor, and GPIOs.
> >
> > Configure AD7292 devices in direct access mode, enabling single-ended
> > ADC readings.
> >
> > Datasheet:
> > Link: https://www.analog.com/media/en/technical-documentation/data-sheets/ad7292.pdf
> >
> > Signed-off-by: Marcelo Schmitt <[email protected]>
> One totally trivial thing inline if you happen to be respinning.
> Otherwise I'll fix up when applying.
>
> I would like to give a bit of time for others to comment, particularly on the dt
> bindings as I frequently miss problems in them. Hence I won't be applying it today
> but may pick it up later in the week or next weekend.
>
> Thanks,
>
> Jonathan
>
>
> > ---
> > Changelog V2 -> V3:
> > - fix up a typo in channel macros
> >
> > MAINTAINERS | 1 +
> > drivers/iio/adc/Kconfig | 10 ++
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 362 insertions(+)
> > create mode 100644 drivers/iio/adc/ad7292.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 5d00e871c4c6..5941cfc0d6f7 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -818,6 +818,7 @@ M: Marcelo Schmitt <[email protected]>
> > L: [email protected]
> > W: http://ez.analog.com/community/linux-device-drivers
> > S: Supported
> > +F: drivers/iio/adc/ad7292.c
> > F: Documentation/devicetree/bindings/iio/adc/adi,ad7292.yaml
> >
> > ANALOG DEVICES INC AD7606 DRIVER
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index 632b331429c6..02587c990cb5 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -59,6 +59,16 @@ config AD7291
> > To compile this driver as a module, choose M here: the
> > module will be called ad7291.
> >
> > +config AD7292
> > + tristate "Analog Devices AD7292 ADC driver"
> > + depends on SPI
> > + help
> > + Say yes here to build support for Analog Devices AD7292
> > + 8 Channel ADC with temperature sensor.
> > +
> > + To compile this driver as a module, choose M here: the
> > + module will be called ad7292.
> > +
> > config AD7298
> > tristate "Analog Devices AD7298 ADC driver"
> > depends on SPI
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index 4779ab3ff8fb..1818f2f66566 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -11,6 +11,7 @@ obj-$(CONFIG_AD7124) += ad7124.o
> > obj-$(CONFIG_AD7173) += ad7173.o
> > obj-$(CONFIG_AD7266) += ad7266.o
> > obj-$(CONFIG_AD7291) += ad7291.o
> > +obj-$(CONFIG_AD7292) += ad7292.o
> > obj-$(CONFIG_AD7298) += ad7298.o
> > obj-$(CONFIG_AD738X) += ad738x.o
> > obj-$(CONFIG_AD7768) += ad7768-1.o
> > diff --git a/drivers/iio/adc/ad7292.c b/drivers/iio/adc/ad7292.c
> > new file mode 100644
> > index 000000000000..e2badf6ac10d
> > --- /dev/null
> > +++ b/drivers/iio/adc/ad7292.c
> > @@ -0,0 +1,350 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Analog Devices AD7292 SPI ADC driver
> > + *
> > + * Copyright 2019 Analog Devices Inc.
> > + */
> > +
> > +#include <linux/bitfield.h>
> > +#include <linux/device.h>
> > +#include <linux/module.h>
> > +#include <linux/regulator/consumer.h>
> > +#include <linux/spi/spi.h>
> > +
> > +#include <linux/iio/iio.h>
> > +
> > +#define ADI_VENDOR_ID 0x0018
> > +
> > +/* AD7292 registers definition */
> > +#define AD7292_REG_VENDOR_ID 0x00
> > +#define AD7292_REG_CONF_BANK 0x05
> > +#define AD7292_REG_CONV_COMM 0x0E
> > +#define AD7292_REG_ADC_CH(x) (0x10 + (x))
> > +
> > +/* AD7292 configuration bank subregisters definition */
> > +#define AD7292_BANK_REG_VIN_RNG0 0x10
> > +#define AD7292_BANK_REG_VIN_RNG1 0x11
> > +#define AD7292_BANK_REG_SAMP_MODE 0x12
> > +
> > +#define AD7292_RD_FLAG_MSK(x) (BIT(7) | ((x) & 0x3F))
> > +
> > +/* AD7292_REG_ADC_CONVERSION */
> > +#define AD7292_ADC_DATA_MASK GENMASK(15, 6)
> > +#define AD7292_ADC_DATA(x) FIELD_GET(AD7292_ADC_DATA_MASK, x)
> > +
> > +/* AD7292_CHANNEL_SAMPLING_MODE */
> > +#define AD7292_CH_SAMP_MODE(reg, ch) ((reg >> 8) & BIT(ch))
Maybe this one would also need to be changed for the same reason:
(((reg) >> 8) & BIT(ch)).
> > +
> > +/* AD7292_CHANNEL_VIN_RANGE */
> > +#define AD7292_CH_VIN_RANGE(reg, ch) (reg & BIT(ch))
>
> Trivial but all macro parameters should be in brackets to prevent
> weirdness if some sticks a parameter with higher precedence in there
> so ((reg) & BIT(ch)).
>
> I can fix this up if the rest is fine.
Since I'll be respinning, I can add the brackets.
>
> > +
> > +#define AD7292_VOLTAGE_CHAN(_chan) \
> > +{ \
> > + .type = IIO_VOLTAGE, \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
> > + BIT(IIO_CHAN_INFO_SCALE), \
> > + .indexed = 1, \
> > + .channel = _chan, \
> > +}
> > +
> > +static const struct iio_chan_spec ad7292_channels[] = {
> > + AD7292_VOLTAGE_CHAN(0),
> > + AD7292_VOLTAGE_CHAN(1),
> > + AD7292_VOLTAGE_CHAN(2),
> > + AD7292_VOLTAGE_CHAN(3),
> > + AD7292_VOLTAGE_CHAN(4),
> > + AD7292_VOLTAGE_CHAN(5),
> > + AD7292_VOLTAGE_CHAN(6),
> > + AD7292_VOLTAGE_CHAN(7)
> > +};
> > +
> > +static const struct iio_chan_spec ad7292_channels_diff[] = {
> > + {
> > + .type = IIO_VOLTAGE,
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> > + .indexed = 1,
> > + .differential = 1,
> > + .channel = 0,
> > + .channel2 = 1,
> > + },
> > + AD7292_VOLTAGE_CHAN(2),
> > + AD7292_VOLTAGE_CHAN(3),
> > + AD7292_VOLTAGE_CHAN(4),
> > + AD7292_VOLTAGE_CHAN(5),
> > + AD7292_VOLTAGE_CHAN(6),
> > + AD7292_VOLTAGE_CHAN(7)
> > +};
> > +
> > +struct ad7292_state {
> > + struct spi_device *spi;
> > + struct regulator *reg;
> > + unsigned short vref_mv;
> > +
> > + __be16 d16 ____cacheline_aligned;
> > + u8 d8[2];
> > +};
> > +
> > +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
> > +{
> > + int ret;
> > +
> > + st->d8[0] = AD7292_RD_FLAG_MSK(addr);
> > +
> > + ret = spi_write_then_read(st->spi, st->d8, 1, &st->d16, 2);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return be16_to_cpu(st->d16);
> > +}
> > +
> > +static int ad7292_spi_subreg_read(struct ad7292_state *st, unsigned int addr,
> > + unsigned int sub_addr, unsigned int len)
> > +{
> > + unsigned int shift = 16 - (8 * len);
> > + int ret;
> > +
> > + st->d8[0] = AD7292_RD_FLAG_MSK(addr);
> > + st->d8[1] = sub_addr;
> > +
> > + ret = spi_write_then_read(st->spi, st->d8, 2, &st->d16, len);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return (be16_to_cpu(st->d16) >> shift);
> > +}
> > +
> > +static int ad7292_single_conversion(struct ad7292_state *st,
> > + unsigned int chan_addr)
> > +{
> > + int ret;
> > +
> > + struct spi_transfer t[] = {
> > + {
> > + .tx_buf = &st->d8,
> > + .len = 4,
> > + .delay_usecs = 6,
> > + }, {
> > + .rx_buf = &st->d16,
> > + .len = 2,
> > + },
> > + };
> > +
> > + st->d8[0] = chan_addr;
> > + st->d8[1] = AD7292_RD_FLAG_MSK(AD7292_REG_CONV_COMM);
> > +
> > + ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
> > +
> > + if (ret < 0)
> > + return ret;
> > +
> > + return be16_to_cpu(st->d16);
> > +}
> > +
> > +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
> > +{
> > + int samp_mode, range0, range1, factor = 1;
> > +
> > + /*
> > + * Every AD7292 ADC channel may have its input range adjusted according
> > + * to the settings at the ADC sampling mode and VIN range subregisters.
> > + * For a given channel, the minimum input range is equal to Vref, and it
> > + * may be increased by a multiplier factor of 2 or 4 according to the
> > + * following rule:
> > + * If channel is being sampled with respect to AGND:
> > + * factor = 4 if VIN range0 and VIN range1 equal 0
> > + * factor = 2 if only one of VIN ranges equal 1
> > + * factor = 1 if both VIN range0 and VIN range1 equal 1
> > + * If channel is being sampled with respect to AVDD:
> > + * factor = 4 if VIN range0 and VIN range1 equal 0
> > + * Behavior is undefined if any of VIN range doesn't equal 0
> > + */
> > +
> > + samp_mode = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> > + AD7292_BANK_REG_SAMP_MODE, 2);
> > +
> > + if (samp_mode < 0)
> > + return samp_mode;
> > +
> > + range0 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> > + AD7292_BANK_REG_VIN_RNG0, 2);
> > +
> > + if (range0 < 0)
> > + return range0;
> > +
> > + range1 = ad7292_spi_subreg_read(st, AD7292_REG_CONF_BANK,
> > + AD7292_BANK_REG_VIN_RNG1, 2);
> > +
> > + if (range1 < 0)
> > + return range1;
> > +
> > + if (AD7292_CH_SAMP_MODE(samp_mode, channel)) {
> > + /* Sampling with respect to AGND */
> > + if (!AD7292_CH_VIN_RANGE(range0, channel))
> > + factor *= 2;
> > +
> > + if (!AD7292_CH_VIN_RANGE(range1, channel))
> > + factor *= 2;
> > +
> > + } else {
> > + /* Sampling with respect to AVDD */
> > + if (AD7292_CH_VIN_RANGE(range0, channel) ||
> > + AD7292_CH_VIN_RANGE(range1, channel))
> > + return -EPERM;
> > +
> > + factor = 4;
> > + }
> > +
> > + return factor;
> > +}
> > +
> > +static int ad7292_read_raw(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + int *val, int *val2, long info)
> > +{
> > + struct ad7292_state *st = iio_priv(indio_dev);
> > + unsigned int ch_addr;
> > + int ret;
> > +
> > + switch (info) {
> > + case IIO_CHAN_INFO_RAW:
> > + ch_addr = AD7292_REG_ADC_CH(chan->channel);
> > + ret = ad7292_single_conversion(st, ch_addr);
> > + if (ret < 0)
> > + return ret;
> > +
> > + *val = AD7292_ADC_DATA(ret);
> > +
> > + return IIO_VAL_INT;
> > + case IIO_CHAN_INFO_SCALE:
> > + /*
> > + * To convert a raw value to standard units, the IIO defines
> > + * this formula: Scaled value = (raw + offset) * scale.
> > + * For the scale to be a correct multiplier for (raw + offset),
> > + * it must be calculated as the input range divided by the
> > + * number of possible distinct input values. Given the ADC data
> > + * is 10 bit long, it may assume 2^10 distinct values.
> > + * Hence, scale = range / 2^10. The IIO_VAL_FRACTIONAL_LOG2
> > + * return type indicates to the IIO API to divide *val by 2 to
> > + * the power of *val2 when returning from read_raw.
> > + */
> > +
> > + ret = ad7292_vin_range_multiplier(st, chan->channel);
> > + if (ret < 0)
> > + return ret;
> > +
> > + *val = st->vref_mv * ret;
> > + *val2 = 10;
> > + return IIO_VAL_FRACTIONAL_LOG2;
> > + default:
> > + break;
> > + }
> > + return -EINVAL;
> > +}
> > +
> > +static const struct iio_info ad7292_info = {
> > + .read_raw = ad7292_read_raw,
> > +};
> > +
> > +static void ad7292_regulator_disable(void *data)
> > +{
> > + struct ad7292_state *st = data;
> > +
> > + regulator_disable(st->reg);
> > +}
> > +
> > +static int ad7292_probe(struct spi_device *spi)
> > +{
> > + struct ad7292_state *st;
> > + struct iio_dev *indio_dev;
> > + struct device_node *child;
> > + bool diff_channels = 0;
> > + 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;
> > +
> > + ret = ad7292_spi_reg_read(st, AD7292_REG_VENDOR_ID);
> > + if (ret != ADI_VENDOR_ID) {
> > + dev_err(&spi->dev, "Wrong vendor id 0x%x\n", ret);
> > + return -EINVAL;
> > + }
> > +
> > + spi_set_drvdata(spi, indio_dev);
> > +
> > + st->reg = devm_regulator_get_optional(&spi->dev, "vref");
> > + if (!IS_ERR(st->reg)) {
> > + ret = regulator_enable(st->reg);
> > + if (ret) {
> > + dev_err(&spi->dev,
> > + "Failed to enable external vref supply\n");
> > + return ret;
> > + }
> > +
> > + ret = devm_add_action_or_reset(&spi->dev,
> > + ad7292_regulator_disable, st);
> > + if (ret) {
> > + regulator_disable(st->reg);
> > + return ret;
> > + }
> > +
> > + ret = regulator_get_voltage(st->reg);
> > + if (ret < 0)
> > + return ret;
> > +
> > + st->vref_mv = ret / 1000;
> > + } else {
> > + /* Use the internal voltage reference. */
> > + st->vref_mv = 1250;
> > + }
> > +
> > + indio_dev->dev.parent = &spi->dev;
> > + indio_dev->name = spi_get_device_id(spi)->name;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > + indio_dev->info = &ad7292_info;
> > +
> > + for_each_available_child_of_node(spi->dev.of_node, child) {
> > + diff_channels = of_property_read_bool(child, "diff-channels");
> > + if (diff_channels)
> > + break;
> > + }
> > +
> > + if (diff_channels) {
> > + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels_diff);
> > + indio_dev->channels = ad7292_channels_diff;
> > + } else {
> > + indio_dev->num_channels = ARRAY_SIZE(ad7292_channels);
> > + indio_dev->channels = ad7292_channels;
> > + }
> > +
> > + return devm_iio_device_register(&spi->dev, indio_dev);
> > +}
> > +
> > +static const struct spi_device_id ad7292_id_table[] = {
> > + { "ad7292", 0 },
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(spi, ad7292_id_table);
> > +
> > +static const struct of_device_id ad7292_of_match[] = {
> > + { .compatible = "adi,ad7292" },
> > + { },
> > +};
> > +MODULE_DEVICE_TABLE(of, ad7292_of_match);
> > +
> > +static struct spi_driver ad7292_driver = {
> > + .driver = {
> > + .name = "ad7292",
> > + .of_match_table = ad7292_of_match,
> > + },
> > + .probe = ad7292_probe,
> > + .id_table = ad7292_id_table,
> > +};
> > +module_spi_driver(ad7292_driver);
> > +
> > +MODULE_AUTHOR("Marcelo Schmitt <[email protected]>");
> > +MODULE_DESCRIPTION("Analog Devices AD7292 ADC driver");
> > +MODULE_LICENSE("GPL v2");
>