[PATCH 0/2] Add support for AD7293 Power Amplifier

[PATCH 0/2] Add support for AD7293 Power Amplifier

[Antoniu Miclaus]

The AD7293 is a Power Amplifier drain current controller containing 
functionality for general-purpose monitoring and control of 
current, voltage, and temperature, integrated into a single chip 
solution with an SPI-compatible interface.

Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7293.pdf

This series of patches provide an initial implementation of the
driver with access from the userspace to the:
 - ADC channels (read raw values, set range, set offset)
 - DAC channels (set code, set offset)
 - Temperature sensing (read raw values, set offset)
 - Current sensing (read raw, set offset, set gain)

Antoniu Miclaus (2):
  iio:amplifiers:ad7293: add support for AD7293
  dt-bindings:iio:amplifiers: add ad7293 doc

 .../bindings/iio/amplifiers/adi,ad7293.yaml   |  49 ++
 drivers/iio/amplifiers/Kconfig                |  11 +
 drivers/iio/amplifiers/Makefile               |   1 +
 drivers/iio/amplifiers/ad7293.c               | 794 ++++++++++++++++++
 4 files changed, 855 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
 create mode 100644 drivers/iio/amplifiers/ad7293.c

-- 
2.33.1

[PATCH 1/2] iio:amplifiers:ad7293: add support for AD7293

[Antoniu Miclaus]

The AD7293 is a Power Amplifier drain current controller
containing functionality for general-purpose monitoring
and control of current, voltage, and temperature, integrated
into a single chip solution with an SPI-compatible interface.

Datasheet:
https://www.analog.com/media/en/technical-documentation/data-sheets/AD7293.pdf
Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
 drivers/iio/amplifiers/Kconfig  |  11 +
 drivers/iio/amplifiers/Makefile |   1 +
 drivers/iio/amplifiers/ad7293.c | 794 ++++++++++++++++++++++++++++++++
 3 files changed, 806 insertions(+)
 create mode 100644 drivers/iio/amplifiers/ad7293.c

diff --git a/drivers/iio/amplifiers/Kconfig b/drivers/iio/amplifiers/Kconfig
index 5eb1357a9c78..c4ff0f123019 100644
--- a/drivers/iio/amplifiers/Kconfig
+++ b/drivers/iio/amplifiers/Kconfig
@@ -6,6 +6,17 @@
 
 menu "Amplifiers"
 
+config AD7293
+	tristate "Analog Devices AD7293 Power Amplifier Current Controller"
+	depends on SPI
+	help
+	  Say yes here to build support for Analog Devices AD7293
+	  Power Amplifier Current Controller with
+	  ADC, DACs, and Temperature and Current Sensors
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad7293.
+
 config AD8366
 	tristate "Analog Devices AD8366 and similar Gain Amplifiers"
 	depends on SPI
diff --git a/drivers/iio/amplifiers/Makefile b/drivers/iio/amplifiers/Makefile
index cb551d82f56b..ddfe007950d8 100644
--- a/drivers/iio/amplifiers/Makefile
+++ b/drivers/iio/amplifiers/Makefile
@@ -4,5 +4,6 @@
 #
 
 # When adding new entries keep the list in alphabetical order
+obj-$(CONFIG_AD7293) += ad7293.o
 obj-$(CONFIG_AD8366) += ad8366.o
 obj-$(CONFIG_HMC425) += hmc425a.o
diff --git a/drivers/iio/amplifiers/ad7293.c b/drivers/iio/amplifiers/ad7293.c
new file mode 100644
index 000000000000..c45b11ec2ce6
--- /dev/null
+++ b/drivers/iio/amplifiers/ad7293.c
@@ -0,0 +1,794 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AD7293 driver
+ *
+ * Copyright 2021 Analog Devices Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/iio/iio.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+/* AD7293 Register Map Common */
+#define AD7293_REG_NO_OP			(AD7293_R1B | AD7293_PAGE(0x0) | 0x0)
+#define AD7293_REG_PAGE_SELECT			(AD7293_R1B | AD7293_PAGE(0x0) | 0x1)
+#define AD7293_REG_CONV_CMD			(AD7293_R2B | AD7293_PAGE(0x0) | 0x2)
+#define AD7293_REG_RESULT			(AD7293_R1B | AD7293_PAGE(0x0) | 0x3)
+#define AD7293_REG_DAC_EN			(AD7293_R1B | AD7293_PAGE(0x0) | 0x4)
+#define AD7293_REG_DEVICE_ID			(AD7293_R2B | AD7293_PAGE(0x0) | 0xC)
+#define AD7293_REG_SOFT_RESET			(AD7293_R2B | AD7293_PAGE(0x0) | 0xF)
+
+/* AD7293 Register Map Page 0x0 */
+#define AD7293_REG_VIN0				(AD7293_R2B | AD7293_PAGE(0x0) | 0x10)
+#define AD7293_REG_VIN1				(AD7293_R2B | AD7293_PAGE(0x0) | 0x11)
+#define AD7293_REG_VIN2				(AD7293_R2B | AD7293_PAGE(0x0) | 0x12)
+#define AD7293_REG_VIN3				(AD7293_R2B | AD7293_PAGE(0x0) | 0x13)
+#define AD7293_REG_TSENSE_INT			(AD7293_R2B | AD7293_PAGE(0x0) | 0x20)
+#define AD7293_REG_TSENSE_D0			(AD7293_R2B | AD7293_PAGE(0x0) | 0x21)
+#define AD7293_REG_TSENSE_D1			(AD7293_R2B | AD7293_PAGE(0x0) | 0x22)
+#define AD7293_REG_ISENSE_0			(AD7293_R2B | AD7293_PAGE(0x0) | 0x28)
+#define AD7293_REG_ISENSE_1			(AD7293_R2B | AD7293_PAGE(0x0) | 0x29)
+#define AD7293_REG_ISENSE_2			(AD7293_R2B | AD7293_PAGE(0x0) | 0x2A)
+#define AD7293_REG_ISENSE_3			(AD7293_R2B | AD7293_PAGE(0x0) | 0x2B)
+#define AD7293_REG_UNI_VOUT0			(AD7293_R2B | AD7293_PAGE(0x0) | 0x30)
+#define AD7293_REG_UNI_VOUT1			(AD7293_R2B | AD7293_PAGE(0x0) | 0x31)
+#define AD7293_REG_UNI_VOUT2			(AD7293_R2B | AD7293_PAGE(0x0) | 0x32)
+#define AD7293_REG_UNI_VOUT3			(AD7293_R2B | AD7293_PAGE(0x0) | 0x33)
+#define AD7293_REG_BI_VOUT0			(AD7293_R2B | AD7293_PAGE(0x0) | 0x34)
+#define AD7293_REG_BI_VOUT1			(AD7293_R2B | AD7293_PAGE(0x0) | 0x35)
+#define AD7293_REG_BI_VOUT2			(AD7293_R2B | AD7293_PAGE(0x0) | 0x36)
+#define AD7293_REG_BI_VOUT3			(AD7293_R2B | AD7293_PAGE(0x0) | 0x37)
+
+/* AD7293 Register Map Page 0x1 */
+#define AD7293_REG_AVDD				(AD7293_R2B | AD7293_PAGE(0x1) | 0x10)
+#define AD7293_REG_DACVDD_UNI			(AD7293_R2B | AD7293_PAGE(0x1) | 0x11)
+#define AD7293_REG_DACVDD_BI			(AD7293_R2B | AD7293_PAGE(0x1) | 0x12)
+#define AD7293_REG_AVSS				(AD7293_R2B | AD7293_PAGE(0x1) | 0x13)
+#define AD7293_REG_BI_VOUT0_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x14)
+#define AD7293_REG_BI_VIOU1_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x15)
+#define AD7293_REG_BI_VOUT2_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x16)
+#define AD7293_REG_BI_VOUT3_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x17)
+#define AD7293_REG_RS0_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x28)
+#define AD7293_REG_RS1_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x29)
+#define AD7293_REG_RS2_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x2A)
+#define AD7293_REG_RS3_MON			(AD7293_R2B | AD7293_PAGE(0x1) | 0x2B)
+
+/* AD7293 Register Map Page 0x2 */
+#define AD7293_REG_DIGITAL_OUT_EN		(AD7293_R2B | AD7293_PAGE(0x2) | 0x11)
+#define AD7293_REG_DIGITAL_INOUT_FUNC		(AD7293_R2B | AD7293_PAGE(0x2) | 0x12)
+#define AD7293_REG_DIGITAL_FUNC_POL		(AD7293_R2B | AD7293_PAGE(0x2) | 0x13)
+#define AD7293_REG_GENERAL			(AD7293_R2B | AD7293_PAGE(0x2) | 0x14)
+#define AD7293_REG_VINX_RANGE0			(AD7293_R2B | AD7293_PAGE(0x2) | 0x15)
+#define AD7293_REG_VINX_RANGE1			(AD7293_R2B | AD7293_PAGE(0x2) | 0x16)
+#define AD7293_REG_VINX_DIFF_SE			(AD7293_R2B | AD7293_PAGE(0x2) | 0x17)
+#define AD7293_REG_VINX_FILTER			(AD7293_R2B | AD7293_PAGE(0x2) | 0x18)
+#define AD7293_REG_BG_EN			(AD7293_R2B | AD7293_PAGE(0x2) | 0x19)
+#define AD7293_REG_CONV_DELAY			(AD7293_R2B | AD7293_PAGE(0x2) | 0x1A)
+#define AD7293_REG_TSENSE_BG_EN			(AD7293_R2B | AD7293_PAGE(0x2) | 0x1B)
+#define AD7293_REG_ISENSE_BG_EN			(AD7293_R2B | AD7293_PAGE(0x2) | 0x1C)
+#define AD7293_REG_ISENSE_GAIN			(AD7293_R2B | AD7293_PAGE(0x2) | 0x1D)
+#define AD7293_REG_DAC_SNOOZE_O			(AD7293_R2B | AD7293_PAGE(0x2) | 0x1F)
+#define AD7293_REG_DAC_SNOOZE_1			(AD7293_R2B | AD7293_PAGE(0x2) | 0x20)
+#define AD7293_REG_RSX_MON_BG_EN		(AD7293_R2B | AD7293_PAGE(0x2) | 0x23)
+#define AD7293_REG_INTEGR_CL			(AD7293_R2B | AD7293_PAGE(0x2) | 0x28)
+#define AD7293_REG_PA_ON_CTRL			(AD7293_R2B | AD7293_PAGE(0x2) | 0x29)
+#define AD7293_REG_RAMP_TIME_0			(AD7293_R2B | AD7293_PAGE(0x2) | 0x2A)
+#define AD7293_REG_RAMP_TIME_1			(AD7293_R2B | AD7293_PAGE(0x2) | 0x2B)
+#define AD7293_REG_RAMP_TIME_2			(AD7293_R2B | AD7293_PAGE(0x2) | 0x2C)
+#define AD7293_REG_RAMP_TIME_3			(AD7293_R2B | AD7293_PAGE(0x2) | 0x2D)
+#define AD7293_REG_CL_FR_IT			(AD7293_R2B | AD7293_PAGE(0x2) | 0x2E)
+#define AD7293_REG_INTX_AVSS_AVDD		(AD7293_R2B | AD7293_PAGE(0x2) | 0x2F)
+
+/* AD7293 Register Map Page 0x3 */
+#define AD7293_REG_VINX_SEQ			(AD7293_R2B | AD7293_PAGE(0x3) | 0x10)
+#define AD7293_REG_ISENSEX_TSENSEX_SEQ		(AD7293_R2B | AD7293_PAGE(0x3) | 0x11)
+#define AD7293_REG_RSX_MON_BI_VOUTX_SEQ		(AD7293_R2B | AD7293_PAGE(0x3) | 0x12)
+
+/* AD7293 Register Map Page 0xE */
+#define AD7293_REG_VIN0_OFFSET			(AD7293_R1B | AD7293_PAGE(0xE) | 0x10)
+#define AD7293_REG_VIN1_OFFSET			(AD7293_R1B | AD7293_PAGE(0xE) | 0x11)
+#define AD7293_REG_VIN2_OFFSET			(AD7293_R1B | AD7293_PAGE(0xE) | 0x12)
+#define AD7293_REG_VIN3_OFFSET			(AD7293_R1B | AD7293_PAGE(0xE) | 0x13)
+#define AD7293_REG_TSENSE_INT_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x20)
+#define AD7293_REG_TSENSE_D0_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x21)
+#define AD7293_REG_TSENSE_D1_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x22)
+#define AD7293_REG_ISENSE0_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x28)
+#define AD7293_REG_ISENSE1_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x29)
+#define AD7293_REG_ISENSE2_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x2A)
+#define AD7293_REG_ISENSE3_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x2B)
+#define AD7293_REG_UNI_VOUT0_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x30)
+#define AD7293_REG_UNI_VOUT1_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x31)
+#define AD7293_REG_UNI_VOUT2_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x32)
+#define AD7293_REG_UNI_VOUT3_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x33)
+#define AD7293_REG_BI_VOUT0_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x34)
+#define AD7293_REG_BI_VOUT1_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x35)
+#define AD7293_REG_BI_VOUT2_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x36)
+#define AD7293_REG_BI_VOUT3_OFFSET		(AD7293_R1B | AD7293_PAGE(0xE) | 0x37)
+
+/* AD7293 Miscellaneous Definitions */
+#define AD7293_READ				BIT(7)
+#define AD7293_R1B				BIT(16)
+#define AD7293_R2B				BIT(17)
+#define AD7293_TRANSF_LEN_MSK			GENMASK(17, 16)
+#define AD7293_PAGE_ADDR_MSK			GENMASK(15, 8)
+#define AD7293_PAGE(x)				FIELD_PREP(AD7293_PAGE_ADDR_MSK, x)
+#define AD7293_REG_ADDR_MSK			GENMASK(7, 0)
+#define AD7293_REG_VOUT_OFFSET_MSK		GENMASK(5, 4)
+#define AD7293_REG_DATA_RAW_MSK			GENMASK(15, 4)
+#define AD7293_REG_VINX_RANGE_GET_CH_MSK(x, ch)	(((x) >> (ch)) & 0x1)
+#define AD7293_REG_VINX_RANGE_SET_CH_MSK(x, ch)	(((x) & 0x1) << (ch))
+#define AD7293_CHIP_ID				0x18
+
+enum ad7293_ch_type {
+	AD7293_ADC_VINX,
+	AD7293_ADC_TSENSE,
+	AD7293_ADC_ISENSE,
+	AD7293_DAC,
+};
+
+static const int dac_offset_table[] = {0, 1, 2};
+
+static const int isense_gain_table[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
+
+static const int adc_range_table[] = {0, 1, 2, 3};
+
+struct ad7293_state {
+	struct spi_device *spi;
+	/* Protect against concurrent accesses to the device */
+	struct mutex lock;
+	u8 page_select;
+	u8 data[3] ____cacheline_aligned;
+};
+
+static int ad7293_page_select(struct ad7293_state *st, unsigned int reg)
+{
+	int ret;
+
+	if (st->page_select != FIELD_GET(AD7293_PAGE_ADDR_MSK, reg)) {
+		st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, AD7293_REG_PAGE_SELECT);
+		st->data[1] = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);
+
+		ret = spi_write(st->spi, &st->data[0], 2);
+		if (ret)
+			return ret;
+
+		st->page_select = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);
+	}
+
+	return 0;
+}
+
+static int __ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
+			     unsigned int *val)
+{
+	int ret;
+	struct spi_transfer t = {0};
+
+	ret = ad7293_page_select(st, reg);
+	if (ret)
+		return ret;
+
+	st->data[0] = AD7293_READ | FIELD_GET(AD7293_REG_ADDR_MSK, reg);
+	st->data[1] = 0x0;
+	st->data[2] = 0x0;
+
+	t.tx_buf = &st->data[0];
+	t.rx_buf = &st->data[0];
+	t.len = 1 + FIELD_GET(AD7293_TRANSF_LEN_MSK, reg);
+
+	ret = spi_sync_transfer(st->spi, &t, 1);
+	if (ret)
+		return ret;
+
+	*val = ((st->data[1] << 8) | st->data[2]) >> (8 * (2 - FIELD_GET(AD7293_TRANSF_LEN_MSK, reg)));
+
+	return 0;
+}
+
+static int ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
+			   unsigned int *val)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+	ret = __ad7293_spi_read(st, reg, val);
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int __ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
+			      unsigned int val)
+{
+	int ret;
+
+	ret = ad7293_page_select(st, reg);
+	if (ret)
+		return ret;
+
+	st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, reg);
+
+	if (FIELD_GET(AD7293_TRANSF_LEN_MSK, reg) == 1) {
+		st->data[1] = val;
+	} else {
+		st->data[1] = val >> 8;
+		st->data[2] = val;
+	}
+
+	return spi_write(st->spi, &st->data[0], 1 + FIELD_GET(AD7293_TRANSF_LEN_MSK, reg));
+}
+
+static int ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
+			    unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+	ret = __ad7293_spi_write(st, reg, val);
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int __ad7293_spi_update_bits(struct ad7293_state *st, unsigned int reg,
+				    unsigned int mask, unsigned int val)
+{
+	int ret;
+	unsigned int data, temp;
+
+	ret = __ad7293_spi_read(st, reg, &data);
+	if (ret)
+		return ret;
+
+	temp = (data & ~mask) | (val & mask);
+
+	return __ad7293_spi_write(st, reg, temp);
+}
+
+static int ad7293_spi_update_bits(struct ad7293_state *st, unsigned int reg,
+				  unsigned int mask, unsigned int val)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+	ret = __ad7293_spi_update_bits(st, reg, mask, val);
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad7293_adc_get_scale(struct ad7293_state *st, unsigned int ch, unsigned int *range)
+{
+	int ret;
+	unsigned int data;
+
+	mutex_lock(&st->lock);
+
+	ret = __ad7293_spi_read(st, AD7293_REG_VINX_RANGE1, &data);
+	if (ret)
+		goto exit;
+
+	*range = AD7293_REG_VINX_RANGE_GET_CH_MSK(data, ch);
+
+	ret = __ad7293_spi_read(st, AD7293_REG_VINX_RANGE0, &data);
+	if (ret)
+		goto exit;
+
+	*range |= AD7293_REG_VINX_RANGE_GET_CH_MSK(data, ch) << 1;
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad7293_adc_set_scale(struct ad7293_state *st, unsigned int ch, unsigned int range)
+{
+	int ret;
+	unsigned int ch_msk = 1 << ch;
+
+	mutex_lock(&st->lock);
+	ret = __ad7293_spi_update_bits(st, AD7293_REG_VINX_RANGE1, ch_msk,
+				       AD7293_REG_VINX_RANGE_SET_CH_MSK(range, ch));
+	if (ret)
+		goto exit;
+
+	ret = __ad7293_spi_update_bits(st, AD7293_REG_VINX_RANGE0, ch_msk,
+				       AD7293_REG_VINX_RANGE_SET_CH_MSK((range >> 1), ch));
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad7293_get_offset(struct ad7293_state *st, unsigned int ch, unsigned int *offset)
+{
+	if (ch < 4)
+		return ad7293_spi_read(st, AD7293_REG_VIN0_OFFSET + ch, offset);
+	else if (ch < 7)
+		return ad7293_spi_read(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - 4), offset);
+	else if (ch < 11)
+		return ad7293_spi_read(st, AD7293_REG_ISENSE0_OFFSET + (ch - 7), offset);
+	else if (ch < 19)
+		return ad7293_spi_read(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - 11), offset);
+	else
+		return -EINVAL;
+}
+
+static int ad7293_set_offset(struct ad7293_state *st, unsigned int ch, unsigned int offset)
+{
+	if (ch < 4)
+		return ad7293_spi_write(st, AD7293_REG_VIN0_OFFSET + ch, offset);
+	else if (ch < 7)
+		return ad7293_spi_write(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - 4), offset);
+	else if (ch < 11)
+		return ad7293_spi_write(st, AD7293_REG_ISENSE0_OFFSET + (ch - 7), offset);
+	else if (ch < 19)
+		return ad7293_spi_update_bits(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - 11),
+						AD7293_REG_VOUT_OFFSET_MSK,
+						FIELD_PREP(AD7293_REG_VOUT_OFFSET_MSK, offset));
+	else
+		return -EINVAL;
+}
+
+static int ad7293_isense_set_gain(struct ad7293_state *st, unsigned int ch, unsigned int gain)
+{
+	unsigned int ch_msk = (0xf << (4 * ch));
+
+	return ad7293_spi_update_bits(st, AD7293_REG_ISENSE_GAIN, ch_msk, gain << (4 * ch));
+}
+
+static int ad7293_isense_get_gain(struct ad7293_state *st, unsigned int ch, unsigned int *gain)
+{
+	int ret;
+
+	ret = ad7293_spi_read(st, AD7293_REG_ISENSE_GAIN, gain);
+	if (ret)
+		return ret;
+
+	*gain = (*gain >> (4 * ch)) & 0xf;
+
+	return ret;
+}
+
+static int ad7293_dac_write_raw(struct ad7293_state *st, unsigned int ch, unsigned int raw)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = __ad7293_spi_update_bits(st, AD7293_REG_DAC_EN, 1 << ch, 1 << ch);
+	if (ret)
+		goto exit;
+
+	ret =  __ad7293_spi_write(st, AD7293_REG_UNI_VOUT0 + ch,
+				  FIELD_PREP(AD7293_REG_DATA_RAW_MSK, raw));
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad7293_ch_read_raw(struct ad7293_state *st, enum ad7293_ch_type type, unsigned int ch,
+			      unsigned int *raw)
+{
+	int ret;
+	unsigned int reg_wr, reg_rd, data_wr;
+
+	switch (type) {
+	case AD7293_ADC_VINX:
+		reg_wr = AD7293_REG_VINX_SEQ;
+		reg_rd = AD7293_REG_VIN0 + ch;
+		data_wr = 1 << ch;
+
+		break;
+	case AD7293_ADC_TSENSE:
+		reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
+		reg_rd = AD7293_REG_TSENSE_INT + ch;
+		data_wr = 1 << ch;
+
+		break;
+	case AD7293_ADC_ISENSE:
+		reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
+		reg_rd = AD7293_REG_ISENSE_0 + ch;
+		data_wr = (1 << ch) << 8;
+
+		break;
+	case AD7293_DAC:
+		reg_rd = AD7293_REG_UNI_VOUT0 + ch;
+
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mutex_lock(&st->lock);
+
+	if (type != AD7293_DAC) {
+		if (type == AD7293_ADC_TSENSE) {
+			ret = __ad7293_spi_write(st, AD7293_REG_TSENSE_BG_EN, 1 << ch);
+			if (ret)
+				goto exit;
+
+			usleep_range(9000, 9900);
+		} else if (type == AD7293_ADC_ISENSE) {
+			ret = __ad7293_spi_write(st, AD7293_REG_ISENSE_BG_EN, 1 << ch);
+			if (ret)
+				goto exit;
+
+			usleep_range(2000, 7000);
+		}
+
+		ret = __ad7293_spi_write(st, reg_wr, data_wr);
+		if (ret)
+			goto exit;
+
+		ret = __ad7293_spi_write(st, AD7293_REG_CONV_CMD, 0x82);
+		if (ret)
+			goto exit;
+	}
+
+	ret = __ad7293_spi_read(st, reg_rd, raw);
+
+	*raw = FIELD_GET(AD7293_REG_DATA_RAW_MSK, *raw);
+
+exit:
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int ad7293_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long info)
+{
+	struct ad7293_state *st = iio_priv(indio_dev);
+	int ret;
+	unsigned int data;
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output)
+				ret =  ad7293_ch_read_raw(st, AD7293_DAC, chan->channel, &data);
+			else
+				ret =  ad7293_ch_read_raw(st, AD7293_ADC_VINX, chan->channel, &data);
+
+			break;
+		case IIO_CURRENT:
+			ret =  ad7293_ch_read_raw(st, AD7293_ADC_ISENSE, chan->channel, &data);
+
+			break;
+		case IIO_TEMP:
+			ret =  ad7293_ch_read_raw(st, AD7293_ADC_TSENSE, chan->channel, &data);
+
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		if (ret)
+			return ret;
+
+		*val = data;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output) {
+				ret = ad7293_get_offset(st, chan->channel + 11, &data);
+
+				data = FIELD_GET(AD7293_REG_VOUT_OFFSET_MSK, data);
+			} else {
+				ret = ad7293_get_offset(st, chan->channel, &data);
+			}
+
+			break;
+		case IIO_CURRENT:
+			ret = ad7293_get_offset(st, chan->channel + 7, &data);
+
+			break;
+		case IIO_TEMP:
+			ret = ad7293_get_offset(st, chan->channel + 4, &data);
+
+			break;
+		default:
+			return -EINVAL;
+		}
+		if (ret)
+			return ret;
+
+		*val = data;
+
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			ret = ad7293_adc_get_scale(st, chan->channel, &data);
+			if (ret)
+				return ret;
+
+			*val = data;
+
+			return IIO_VAL_INT;
+
+		case IIO_TEMP:
+			*val = 1;
+			*val2 = 8;
+
+			return IIO_VAL_FRACTIONAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		ret = ad7293_isense_get_gain(st, chan->channel, &data);
+		if (ret)
+			return ret;
+
+		*val = data;
+
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad7293_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long info)
+{
+	struct ad7293_state *st = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output)
+				return ad7293_dac_write_raw(st, chan->channel, val);
+
+			return -EINVAL;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output)
+				return ad7293_set_offset(st, chan->channel + 11, val);
+			else
+				return ad7293_set_offset(st, chan->channel, val);
+		case IIO_CURRENT:
+			return ad7293_set_offset(st, chan->channel + 7, val);
+		case IIO_TEMP:
+			return ad7293_set_offset(st, chan->channel + 4, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			return ad7293_adc_set_scale(st, chan->channel, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		return ad7293_isense_set_gain(st, chan->channel, val);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ad7293_reg_access(struct iio_dev *indio_dev,
+			     unsigned int reg,
+			     unsigned int write_val,
+			     unsigned int *read_val)
+{
+	struct ad7293_state *st = iio_priv(indio_dev);
+	int ret;
+
+	if (read_val)
+		ret = ad7293_spi_read(st, reg, read_val);
+	else
+		ret = ad7293_spi_write(st, reg, write_val);
+
+	return ret;
+}
+
+static int ad7293_read_avail(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     const int **vals, int *type, int *length,
+			     long info)
+{
+	switch (info) {
+	case IIO_CHAN_INFO_OFFSET:
+		*vals = (const int *)dac_offset_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(dac_offset_table);
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_HARDWAREGAIN:
+		*vals = (const int *)isense_gain_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(isense_gain_table);
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SCALE:
+		*vals = (const int *)adc_range_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(adc_range_table);
+
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+#define AD7293_CHAN_ADC(_channel) {				\
+	.type = IIO_VOLTAGE,					\
+	.output = 0,						\
+	.indexed = 1,						\
+	.channel = _channel,					\
+	.info_mask_separate =					\
+		BIT(IIO_CHAN_INFO_RAW) |			\
+		BIT(IIO_CHAN_INFO_SCALE) |			\
+		BIT(IIO_CHAN_INFO_OFFSET),			\
+	.info_mask_shared_by_type_available =			\
+		BIT(IIO_CHAN_INFO_SCALE)			\
+}
+
+#define AD7293_CHAN_DAC(_channel) {				\
+	.type = IIO_VOLTAGE,					\
+	.output = 1,						\
+	.indexed = 1,						\
+	.channel = _channel,					\
+	.info_mask_separate =					\
+		BIT(IIO_CHAN_INFO_RAW) |			\
+		BIT(IIO_CHAN_INFO_OFFSET),			\
+	.info_mask_shared_by_type_available =			\
+		BIT(IIO_CHAN_INFO_OFFSET),			\
+}
+
+#define AD7293_CHAN_ISENSE(_channel) {				\
+	.type = IIO_CURRENT,					\
+	.output = 0,						\
+	.indexed = 1,						\
+	.channel = _channel,					\
+	.info_mask_separate =					\
+		BIT(IIO_CHAN_INFO_RAW) |			\
+		BIT(IIO_CHAN_INFO_OFFSET) |			\
+		BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\
+	.info_mask_shared_by_type_available =			\
+		BIT(IIO_CHAN_INFO_HARDWAREGAIN)			\
+}
+
+#define AD7293_CHAN_TEMP(_channel) {				\
+	.type = IIO_TEMP,					\
+	.output = 0,						\
+	.indexed = 1,						\
+	.channel = _channel,					\
+	.info_mask_separate =					\
+		BIT(IIO_CHAN_INFO_RAW) |			\
+		BIT(IIO_CHAN_INFO_OFFSET),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)	\
+}
+
+static const struct iio_chan_spec ad7293_channels[] = {
+	AD7293_CHAN_ADC(0),
+	AD7293_CHAN_ADC(1),
+	AD7293_CHAN_ADC(2),
+	AD7293_CHAN_ADC(3),
+	AD7293_CHAN_ISENSE(0),
+	AD7293_CHAN_ISENSE(1),
+	AD7293_CHAN_ISENSE(2),
+	AD7293_CHAN_ISENSE(3),
+	AD7293_CHAN_TEMP(0),
+	AD7293_CHAN_TEMP(1),
+	AD7293_CHAN_TEMP(2),
+	AD7293_CHAN_DAC(0),
+	AD7293_CHAN_DAC(1),
+	AD7293_CHAN_DAC(2),
+	AD7293_CHAN_DAC(3),
+	AD7293_CHAN_DAC(4),
+	AD7293_CHAN_DAC(5),
+	AD7293_CHAN_DAC(6),
+	AD7293_CHAN_DAC(7)
+};
+
+static int ad7293_init(struct ad7293_state *st)
+{
+	int ret;
+	unsigned int chip_id;
+	struct spi_device *spi = st->spi;
+
+	/* Perform software reset */
+	ret = __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x7293);
+	if (ret)
+		return ret;
+
+	ret = __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x0000);
+	if (ret)
+		return ret;
+
+	/* Check Chip ID */
+	ret = __ad7293_spi_read(st, AD7293_REG_DEVICE_ID, &chip_id);
+	if (ret)
+		return ret;
+
+	if (chip_id != AD7293_CHIP_ID) {
+		dev_err(&spi->dev, "Invalid Chip ID.\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct iio_info ad7293_info = {
+	.read_raw = ad7293_read_raw,
+	.write_raw = ad7293_write_raw,
+	.read_avail = &ad7293_read_avail,
+	.debugfs_reg_access = &ad7293_reg_access,
+};
+
+static int ad7293_probe(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev;
+	struct ad7293_state *st;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	st = iio_priv(indio_dev);
+
+	indio_dev->info = &ad7293_info;
+	indio_dev->name = "ad7293";
+	indio_dev->channels = ad7293_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ad7293_channels);
+
+	st->spi = spi;
+	st->page_select = 0;
+
+	mutex_init(&st->lock);
+
+	ret = ad7293_init(st);
+	if (ret)
+		return ret;
+
+	return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad7293_id[] = {
+	{ "ad7293", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, ad7293_id);
+
+static const struct of_device_id ad7293_of_match[] = {
+	{ .compatible = "adi,ad7293" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, ad7293_of_match);
+
+static struct spi_driver ad7293_driver = {
+	.driver = {
+		.name = "ad7293",
+		.of_match_table = ad7293_of_match,
+	},
+	.probe = ad7293_probe,
+	.id_table = ad7293_id,
+};
+module_spi_driver(ad7293_driver);
+
+MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com");
+MODULE_DESCRIPTION("Analog Devices AD7293");
+MODULE_LICENSE("GPL v2");
-- 
2.33.1

Re: [PATCH 1/2] iio:amplifiers:ad7293: add support for AD7293

[Jonathan Cameron]

On Tue, 2 Nov 2021 15:59:46 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> The AD7293 is a Power Amplifier drain current controller
> containing functionality for general-purpose monitoring
> and control of current, voltage, and temperature, integrated
> into a single chip solution with an SPI-compatible interface.
> 
> Datasheet:
> https://www.analog.com/media/en/technical-documentation/data-sheets/AD7293.pdf
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>

Hi Antoniu,

Looks pretty good to me, a few questions / comments inline.

Thanks,

Jonathan


...


> diff --git a/drivers/iio/amplifiers/ad7293.c b/drivers/iio/amplifiers/ad7293.c
> new file mode 100644
> index 000000000000..c45b11ec2ce6
> --- /dev/null
> +++ b/drivers/iio/amplifiers/ad7293.c

...

> +/* AD7293 Miscellaneous Definitions */
> +#define AD7293_READ				BIT(7)
> +#define AD7293_R1B				BIT(16)
> +#define AD7293_R2B				BIT(17)
> +#define AD7293_TRANSF_LEN_MSK			GENMASK(17, 16)
> +#define AD7293_PAGE_ADDR_MSK			GENMASK(15, 8)
> +#define AD7293_PAGE(x)				FIELD_PREP(AD7293_PAGE_ADDR_MSK, x)
> +#define AD7293_REG_ADDR_MSK			GENMASK(7, 0)
> +#define AD7293_REG_VOUT_OFFSET_MSK		GENMASK(5, 4)
> +#define AD7293_REG_DATA_RAW_MSK			GENMASK(15, 4)
> +#define AD7293_REG_VINX_RANGE_GET_CH_MSK(x, ch)	(((x) >> (ch)) & 0x1)
> +#define AD7293_REG_VINX_RANGE_SET_CH_MSK(x, ch)	(((x) & 0x1) << (ch))
> +#define AD7293_CHIP_ID				0x18
> +
> +enum ad7293_ch_type {
> +	AD7293_ADC_VINX,
> +	AD7293_ADC_TSENSE,
> +	AD7293_ADC_ISENSE,
> +	AD7293_DAC,
> +};
> +
> +static const int dac_offset_table[] = {0, 1, 2};
> +
> +static const int isense_gain_table[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
> +
> +static const int adc_range_table[] = {0, 1, 2, 3};
> +
> +struct ad7293_state {
> +	struct spi_device *spi;
> +	/* Protect against concurrent accesses to the device */

Make it clear this lock also protects the content of data and I'd guess
page_select.

> +	struct mutex lock;
> +	u8 page_select;
> +	u8 data[3] ____cacheline_aligned;
> +};
> +
> +static int ad7293_page_select(struct ad7293_state *st, unsigned int reg)
> +{
> +	int ret;
> +
> +	if (st->page_select != FIELD_GET(AD7293_PAGE_ADDR_MSK, reg)) {
> +		st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, AD7293_REG_PAGE_SELECT);
> +		st->data[1] = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);
> +
> +		ret = spi_write(st->spi, &st->data[0], 2);
> +		if (ret)
> +			return ret;
> +
> +		st->page_select = FIELD_GET(AD7293_PAGE_ADDR_MSK, reg);
> +	}
> +
> +	return 0;
> +}
> +
> +static int __ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
> +			     unsigned int *val)
> +{
> +	int ret;
> +	struct spi_transfer t = {0};
> +
> +	ret = ad7293_page_select(st, reg);
> +	if (ret)
> +		return ret;
> +
> +	st->data[0] = AD7293_READ | FIELD_GET(AD7293_REG_ADDR_MSK, reg);
> +	st->data[1] = 0x0;
> +	st->data[2] = 0x0;
> +
> +	t.tx_buf = &st->data[0];
> +	t.rx_buf = &st->data[0];
> +	t.len = 1 + FIELD_GET(AD7293_TRANSF_LEN_MSK, reg);
> +
> +	ret = spi_sync_transfer(st->spi, &t, 1);
> +	if (ret)
> +		return ret;
> +
> +	*val = ((st->data[1] << 8) | st->data[2])

This part is a get_unaligned_be16()

> >> (8 * (2 - FIELD_GET(AD7293_TRANSF_LEN_MSK, reg)));

This part is presumably only ever taking the values 8 or 0, so really 
reflects selecting either u8 or u16 data depending on the register.
I'd be tempted to make that explicit, even if it involves picking between
two functions based on the register.

This is reading back a relatively small unsigned int.  I'd suggest either making val a u16 or
possibly just use the return value.  Negative for error and >= 0 when successful read.

> +
> +	return 0;
> +}
> +
> +static int ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
> +			   unsigned int *val)
> +{
> +	int ret;
> +
> +	mutex_lock(&st->lock);
> +	ret = __ad7293_spi_read(st, reg, val);
> +	mutex_unlock(&st->lock);
> +
> +	return ret;
> +}
> +
> +static int __ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
> +			      unsigned int val)
> +{
> +	int ret;
> +
> +	ret = ad7293_page_select(st, reg);
> +	if (ret)
> +		return ret;
> +
> +	st->data[0] = FIELD_GET(AD7293_REG_ADDR_MSK, reg);
> +
> +	if (FIELD_GET(AD7293_TRANSF_LEN_MSK, reg) == 1) {
> +		st->data[1] = val;
> +	} else {
> +		st->data[1] = val >> 8;
> +		st->data[2] = val;
> +	}
> +
> +	return spi_write(st->spi, &st->data[0], 1 + FIELD_GET(AD7293_TRANSF_LEN_MSK, reg));

Have a local variable for length.

> +}
> +

...

> +
> +static int ad7293_get_offset(struct ad7293_state *st, unsigned int ch, unsigned int *offset)
> +{
> +	if (ch < 4)

Use an enum for the channel numbers so we know what these are.  
May be clearer as a switch with all the individual elements called out.

> +		return ad7293_spi_read(st, AD7293_REG_VIN0_OFFSET + ch, offset);
> +	else if (ch < 7)
> +		return ad7293_spi_read(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - 4), offset);
> +	else if (ch < 11)
> +		return ad7293_spi_read(st, AD7293_REG_ISENSE0_OFFSET + (ch - 7), offset);
> +	else if (ch < 19)
> +		return ad7293_spi_read(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - 11), offset);
> +	else
> +		return -EINVAL;
> +}
> +

...
> +
> +static int ad7293_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val, int val2, long info)
> +{
> +	struct ad7293_state *st = iio_priv(indio_dev);
> +
> +	switch (info) {
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			if (chan->output)
> +				return ad7293_dac_write_raw(st, chan->channel, val);

Flip conditions like this to, where possible, put the error path as the
out of line one.  Leads to shorter lines and more readable code.

> +
> +			return -EINVAL;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_OFFSET:
> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			if (chan->output)
> +				return ad7293_set_offset(st, chan->channel + 11, val);
> +			else
> +				return ad7293_set_offset(st, chan->channel, val);
> +		case IIO_CURRENT:
> +			return ad7293_set_offset(st, chan->channel + 7, val);
> +		case IIO_TEMP:
> +			return ad7293_set_offset(st, chan->channel + 4, val);
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			return ad7293_adc_set_scale(st, chan->channel, val);
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_HARDWAREGAIN:
> +		return ad7293_isense_set_gain(st, chan->channel, val);
> +	default:
> +		return -EINVAL;
> +	}
> +}

...

> +
> +static int ad7293_read_avail(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     const int **vals, int *type, int *length,
> +			     long info)
> +{
> +	switch (info) {
> +	case IIO_CHAN_INFO_OFFSET:
> +		*vals = (const int *)dac_offset_table;

Do you need the casts here? It's a const int 1D array so from what I
recall it shouldn't need the cast.  We tend to need them because
of a 2D structure which we are flattening but that's not true here.

> +		*type = IIO_VAL_INT;
> +		*length = ARRAY_SIZE(dac_offset_table);
> +
> +		return IIO_AVAIL_LIST;
> +	case IIO_CHAN_INFO_HARDWAREGAIN:
> +		*vals = (const int *)isense_gain_table;
> +		*type = IIO_VAL_INT;
> +		*length = ARRAY_SIZE(isense_gain_table);
> +
> +		return IIO_AVAIL_LIST;
> +	case IIO_CHAN_INFO_SCALE:
> +		*vals = (const int *)adc_range_table;
> +		*type = IIO_VAL_INT;
> +		*length = ARRAY_SIZE(adc_range_table);
> +
> +		return IIO_AVAIL_LIST;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +#define AD7293_CHAN_ADC(_channel) {				\
> +	.type = IIO_VOLTAGE,					\
> +	.output = 0,						\
> +	.indexed = 1,						\
> +	.channel = _channel,					\
> +	.info_mask_separate =					\
> +		BIT(IIO_CHAN_INFO_RAW) |			\
> +		BIT(IIO_CHAN_INFO_SCALE) |			\
> +		BIT(IIO_CHAN_INFO_OFFSET),			\
> +	.info_mask_shared_by_type_available =			\
> +		BIT(IIO_CHAN_INFO_SCALE)			\
> +}
> +
> +#define AD7293_CHAN_DAC(_channel) {				\
> +	.type = IIO_VOLTAGE,					\
> +	.output = 1,						\
> +	.indexed = 1,						\
> +	.channel = _channel,					\
> +	.info_mask_separate =					\
> +		BIT(IIO_CHAN_INFO_RAW) |			\
> +		BIT(IIO_CHAN_INFO_OFFSET),			\
> +	.info_mask_shared_by_type_available =			\
> +		BIT(IIO_CHAN_INFO_OFFSET),			\
> +}
> +
> +#define AD7293_CHAN_ISENSE(_channel) {				\
> +	.type = IIO_CURRENT,					\
> +	.output = 0,						\
> +	.indexed = 1,						\
> +	.channel = _channel,					\
> +	.info_mask_separate =					\
> +		BIT(IIO_CHAN_INFO_RAW) |			\
> +		BIT(IIO_CHAN_INFO_OFFSET) |			\
> +		BIT(IIO_CHAN_INFO_HARDWAREGAIN),		\

Hardware gain is for cases where we don't directly affect this signal
such as light level on a time of flight sensor where we are measuring time
but adjust the gain of the sensor to make sure we see the event.
In this case looks like this gain has an effect on the scaling of the
read current value?

ISENSE LSB = 2 × (REFADC/(Gain × 4096 × RSENSE))

In which case it should be mapped onto scale.

> +	.info_mask_shared_by_type_available =			\
> +		BIT(IIO_CHAN_INFO_HARDWAREGAIN)			\
> +}
> +

...

[PATCH 2/2] dt-bindings:iio:amplifiers: add ad7293 doc

[Antoniu Miclaus]

Add device tree bindings for the AD7293 Power Amplifier.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
---
 .../bindings/iio/amplifiers/adi,ad7293.yaml   | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml

diff --git a/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml b/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
new file mode 100644
index 000000000000..b9cfd4621fb7
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/amplifiers/adi,ad7293.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: AD7293 12-Bit Power Amplifier Current Controller with ADC,
+       DACs, Temperature and Current Sensors
+
+maintainers:
+  - Antoniu Miclaus <antoniu.miclaus@analog.com>
+
+description: |
+   Power Amplifier drain current controller containing functionality
+   for general-purpose monitoring and control of current, voltage,
+   and temperature, integrated into a single chip solution with an
+   SPI-compatible interface.
+
+   https://www.analog.com/en/products/ad7293.html
+
+properties:
+  compatible:
+    enum:
+      - adi,ad7293
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 1000000
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+      ad7293@0 {
+        compatible = "adi,ad7293";
+        reg = <0>;
+        spi-max-frequency = <1000000>;
+      };
+    };
+...
-- 
2.33.1

Re: [PATCH 2/2] dt-bindings:iio:amplifiers: add ad7293 doc

[Jonathan Cameron]

On Tue, 2 Nov 2021 15:59:47 +0200
Antoniu Miclaus <antoniu.miclaus@analog.com> wrote:

> Add device tree bindings for the AD7293 Power Amplifier.
> 
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>

Hi Antoniu

Whilst the driver may not support all the features, we should
try to describe as many of the hardware connections / power supplies
etc as possible.

From a quick glance, I'm seeing a reset gpio, some alert pins (which I'm
assuming can be used as interrupts, and several power supplies that should
be provided by regulators.

So for v2, please added as much of that as possible.

There may be odd corner cases (e.g. the sleep pins) where we aren't
completely sure how they would be used, which you can leave for when/if
we figure out what makes sense.

Jonathan

> ---
>  .../bindings/iio/amplifiers/adi,ad7293.yaml   | 49 +++++++++++++++++++
>  1 file changed, 49 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml b/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
> new file mode 100644
> index 000000000000..b9cfd4621fb7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/amplifiers/adi,ad7293.yaml
> @@ -0,0 +1,49 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/amplifiers/adi,ad7293.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: AD7293 12-Bit Power Amplifier Current Controller with ADC,
> +       DACs, Temperature and Current Sensors
> +
> +maintainers:
> +  - Antoniu Miclaus <antoniu.miclaus@analog.com>
> +
> +description: |
> +   Power Amplifier drain current controller containing functionality
> +   for general-purpose monitoring and control of current, voltage,
> +   and temperature, integrated into a single chip solution with an
> +   SPI-compatible interface.
> +
> +   https://www.analog.com/en/products/ad7293.html
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ad7293
> +
> +  reg:
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    maximum: 1000000
> +
> +required:
> +  - compatible
> +  - reg
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    spi {
> +      #address-cells = <1>;
> +      #size-cells = <0>;
> +      ad7293@0 {
> +        compatible = "adi,ad7293";
> +        reg = <0>;
> +        spi-max-frequency = <1000000>;
> +      };
> +    };
> +...