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]>
---
MAINTAINERS | 7 +
drivers/iio/adc/Kconfig | 10 ++
drivers/iio/adc/Makefile | 1 +
drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
4 files changed, 368 insertions(+)
create mode 100644 drivers/iio/adc/ad7292.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 32bf5f8116d0..e78317a5f4f1 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: drivers/iio/adc/ad7292.c
+
ANALOG DEVICES INC AD7606 DRIVER
M: Stefan Popa <[email protected]>
L: [email protected]
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..076bd49a2571
--- /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 AD7291_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[] = {
+ AD7291_VOLTAGE_CHAN(0),
+ AD7291_VOLTAGE_CHAN(1),
+ AD7291_VOLTAGE_CHAN(2),
+ AD7291_VOLTAGE_CHAN(3),
+ AD7291_VOLTAGE_CHAN(4),
+ AD7291_VOLTAGE_CHAN(5),
+ AD7291_VOLTAGE_CHAN(6),
+ AD7291_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,
+ },
+ AD7291_VOLTAGE_CHAN(2),
+ AD7291_VOLTAGE_CHAN(3),
+ AD7291_VOLTAGE_CHAN(4),
+ AD7291_VOLTAGE_CHAN(5),
+ AD7291_VOLTAGE_CHAN(6),
+ AD7291_VOLTAGE_CHAN(7)
+};
+
+struct ad7292_state {
+ struct spi_device *spi;
+ struct regulator *reg;
+ unsigned short vref_mv;
+ union {
+ __be16 d16;
+ u8 d8[2];
+ } data ____cacheline_aligned;
+};
+
+static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
+{
+ int ret;
+
+ st->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
+
+ ret = spi_write_then_read(st->spi, st->data.d8, 1, &st->data.d16, 2);
+ if (ret < 0)
+ return ret;
+
+ return be16_to_cpu(st->data.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->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
+ st->data.d8[1] = sub_addr;
+
+ ret = spi_write_then_read(st->spi, st->data.d8, 2, &st->data.d16, len);
+ if (ret < 0)
+ return ret;
+
+ return (be16_to_cpu(st->data.d16) >> shift);
+}
+
+static int ad7292_single_conversion(struct ad7292_state *st,
+ unsigned int chan_addr)
+{
+ int ret;
+
+ struct spi_transfer t[] = {
+ {
+ .tx_buf = &st->data,
+ .len = 4,
+ .delay_usecs = 6,
+ }, {
+ .rx_buf = &st->data.d16,
+ .len = 2,
+ },
+ };
+
+ st->data.d8[0] = chan_addr;
+ st->data.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->data.d16);
+}
+
+static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
+{
+ int samp_mode, range0, range1;
+ int 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 wiht 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 only 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.
+ */
+
+ *val = regulator_get_voltage(st->reg);
+ if (*val < 0)
+ *val = st->vref_mv;
+ else
+ *val /= 1000;
+
+ ret = ad7292_vin_range_multiplier(st, chan->channel);
+ if (ret < 0)
+ return ret;
+
+ *val *= 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;
+ 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 {
+ 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;
+
+ ret = of_property_read_bool(spi->dev.of_node, "diff-channels");
+ if (ret) {
+ 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 Sun, 13 Oct 2019 11:13:22 -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]>
Hi Marcelo
A few minor bits inline. Mostly just the DT binding question.
Thanks,
Jonathan
> ---
> MAINTAINERS | 7 +
> drivers/iio/adc/Kconfig | 10 ++
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
> 4 files changed, 368 insertions(+)
> create mode 100644 drivers/iio/adc/ad7292.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 32bf5f8116d0..e78317a5f4f1 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: drivers/iio/adc/ad7292.c
> +
> ANALOG DEVICES INC AD7606 DRIVER
> M: Stefan Popa <[email protected]>
> L: [email protected]
> 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..076bd49a2571
> --- /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 AD7291_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[] = {
> + AD7291_VOLTAGE_CHAN(0),
> + AD7291_VOLTAGE_CHAN(1),
> + AD7291_VOLTAGE_CHAN(2),
> + AD7291_VOLTAGE_CHAN(3),
> + AD7291_VOLTAGE_CHAN(4),
> + AD7291_VOLTAGE_CHAN(5),
> + AD7291_VOLTAGE_CHAN(6),
> + AD7291_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,
> + },
> + AD7291_VOLTAGE_CHAN(2),
> + AD7291_VOLTAGE_CHAN(3),
> + AD7291_VOLTAGE_CHAN(4),
> + AD7291_VOLTAGE_CHAN(5),
> + AD7291_VOLTAGE_CHAN(6),
> + AD7291_VOLTAGE_CHAN(7)
> +};
> +
> +struct ad7292_state {
> + struct spi_device *spi;
> + struct regulator *reg;
> + unsigned short vref_mv;
> + union {
> + __be16 d16;
> + u8 d8[2];
> + } data ____cacheline_aligned;
Given it is a whole cacheline long anyway, I'd be tempted to just have
these as separate fields.
> +};
> +
> +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
> +{
> + int ret;
> +
> + st->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
> +
> + ret = spi_write_then_read(st->spi, st->data.d8, 1, &st->data.d16, 2);
> + if (ret < 0)
> + return ret;
> +
> + return be16_to_cpu(st->data.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->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
> + st->data.d8[1] = sub_addr;
> +
> + ret = spi_write_then_read(st->spi, st->data.d8, 2, &st->data.d16, len);
> + if (ret < 0)
> + return ret;
> +
> + return (be16_to_cpu(st->data.d16) >> shift);
> +}
> +
> +static int ad7292_single_conversion(struct ad7292_state *st,
> + unsigned int chan_addr)
> +{
> + int ret;
> +
> + struct spi_transfer t[] = {
> + {
> + .tx_buf = &st->data,
> + .len = 4,
> + .delay_usecs = 6,
> + }, {
> + .rx_buf = &st->data.d16,
> + .len = 2,
> + },
> + };
> +
> + st->data.d8[0] = chan_addr;
> + st->data.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->data.d16);
> +}
> +
> +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
> +{
> + int samp_mode, range0, range1;
> + int 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 wiht 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 only 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.
> + */
> +
> + *val = regulator_get_voltage(st->reg);
> + if (*val < 0)
> + *val = st->vref_mv;
> + else
> + *val /= 1000;
> +
> + ret = ad7292_vin_range_multiplier(st, chan->channel);
> + if (ret < 0)
> + return ret;
> +
> + *val *= 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;
> + 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;
We get the voltage here, but then I think we throw it away by rereading it
each time above. No need to get it in both places.
> +
> + st->vref_mv = ret / 1000;
> + } else {
Perhaps add a comment here to say this is the internal 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;
> +
> + ret = of_property_read_bool(spi->dev.of_node, "diff-channels");
I mention in review of the dt patch that this should use the generic
binding support for specifying differential channels.
> + if (ret) {
> + 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");
Hi Jonathan,
Thanks for the review. I'll send a v2 soon.
On 10/14, Jonathan Cameron wrote:
> On Sun, 13 Oct 2019 11:13:22 -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]>
> Hi Marcelo
>
> A few minor bits inline. Mostly just the DT binding question.
>
> Thanks,
>
> Jonathan
>
> > ---
> > MAINTAINERS | 7 +
> > drivers/iio/adc/Kconfig | 10 ++
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/ad7292.c | 350 +++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 368 insertions(+)
> > create mode 100644 drivers/iio/adc/ad7292.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 32bf5f8116d0..e78317a5f4f1 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: drivers/iio/adc/ad7292.c
> > +
> > ANALOG DEVICES INC AD7606 DRIVER
> > M: Stefan Popa <[email protected]>
> > L: [email protected]
> > 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..076bd49a2571
> > --- /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 AD7291_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[] = {
> > + AD7291_VOLTAGE_CHAN(0),
> > + AD7291_VOLTAGE_CHAN(1),
> > + AD7291_VOLTAGE_CHAN(2),
> > + AD7291_VOLTAGE_CHAN(3),
> > + AD7291_VOLTAGE_CHAN(4),
> > + AD7291_VOLTAGE_CHAN(5),
> > + AD7291_VOLTAGE_CHAN(6),
> > + AD7291_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,
> > + },
> > + AD7291_VOLTAGE_CHAN(2),
> > + AD7291_VOLTAGE_CHAN(3),
> > + AD7291_VOLTAGE_CHAN(4),
> > + AD7291_VOLTAGE_CHAN(5),
> > + AD7291_VOLTAGE_CHAN(6),
> > + AD7291_VOLTAGE_CHAN(7)
> > +};
> > +
> > +struct ad7292_state {
> > + struct spi_device *spi;
> > + struct regulator *reg;
> > + unsigned short vref_mv;
> > + union {
> > + __be16 d16;
> > + u8 d8[2];
> > + } data ____cacheline_aligned;
>
> Given it is a whole cacheline long anyway, I'd be tempted to just have
> these as separate fields.
>
> > +};
> > +
> > +static int ad7292_spi_reg_read(struct ad7292_state *st, unsigned int addr)
> > +{
> > + int ret;
> > +
> > + st->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
> > +
> > + ret = spi_write_then_read(st->spi, st->data.d8, 1, &st->data.d16, 2);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return be16_to_cpu(st->data.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->data.d8[0] = AD7292_RD_FLAG_MSK(addr);
> > + st->data.d8[1] = sub_addr;
> > +
> > + ret = spi_write_then_read(st->spi, st->data.d8, 2, &st->data.d16, len);
> > + if (ret < 0)
> > + return ret;
> > +
> > + return (be16_to_cpu(st->data.d16) >> shift);
> > +}
> > +
> > +static int ad7292_single_conversion(struct ad7292_state *st,
> > + unsigned int chan_addr)
> > +{
> > + int ret;
> > +
> > + struct spi_transfer t[] = {
> > + {
> > + .tx_buf = &st->data,
> > + .len = 4,
> > + .delay_usecs = 6,
> > + }, {
> > + .rx_buf = &st->data.d16,
> > + .len = 2,
> > + },
> > + };
> > +
> > + st->data.d8[0] = chan_addr;
> > + st->data.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->data.d16);
> > +}
> > +
> > +static int ad7292_vin_range_multiplier(struct ad7292_state *st, int channel)
> > +{
> > + int samp_mode, range0, range1;
> > + int 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 wiht 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 only 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.
> > + */
> > +
> > + *val = regulator_get_voltage(st->reg);
> > + if (*val < 0)
> > + *val = st->vref_mv;
> > + else
> > + *val /= 1000;
> > +
> > + ret = ad7292_vin_range_multiplier(st, chan->channel);
> > + if (ret < 0)
> > + return ret;
> > +
> > + *val *= 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;
> > + 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;
>
> We get the voltage here, but then I think we throw it away by rereading it
> each time above. No need to get it in both places.
>
> > +
> > + st->vref_mv = ret / 1000;
> > + } else {
>
> Perhaps add a comment here to say this is the internal 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;
> > +
> > + ret = of_property_read_bool(spi->dev.of_node, "diff-channels");
>
> I mention in review of the dt patch that this should use the generic
> binding support for specifying differential channels.
>
> > + if (ret) {
> > + 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");
>
>