[PATCH v3 1/2] iio:amplifiers:ad7293: add support for AD7293

[Antoniu Miclaus <antoniu.miclaus@analog.com>]

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>
---
changes in v3:
 - use `BIT()` macro for shifting
 - return -EINVAL directly
 drivers/iio/amplifiers/Kconfig  |  11 +
 drivers/iio/amplifiers/Makefile |   1 +
 drivers/iio/amplifiers/ad7293.c | 900 ++++++++++++++++++++++++++++++++
 3 files changed, 912 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..bc8de252f951
--- /dev/null
+++ b/drivers/iio/amplifiers/ad7293.c
@@ -0,0 +1,900 @@
+// 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/gpio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+
+#include <asm/unaligned.h>
+
+#define AD7293_R1B				BIT(16)
+#define AD7293_R2B				BIT(17)
+#define AD7293_PAGE_ADDR_MSK			GENMASK(15, 8)
+#define AD7293_PAGE(x)				FIELD_PREP(AD7293_PAGE_ADDR_MSK, x)
+
+/* 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_TRANSF_LEN_MSK			GENMASK(17, 16)
+
+#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,
+};
+
+enum ad7293_max_offset {
+	AD7293_TSENSE_MIN_OFFSET_CH = 4,
+	AD7293_ISENSE_MIN_OFFSET_CH = 7,
+	AD7293_VOUT_MIN_OFFSET_CH = 11,
+	AD7293_VOUT_MAX_OFFSET_CH = 18,
+};
+
+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, page selection and data content */
+	struct mutex lock;
+	struct gpio_desc *gpio_reset;
+	struct regulator *reg_avdd;
+	struct regulator *reg_vdrive;
+	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,
+			     u16 *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;
+
+	if (FIELD_GET(AD7293_TRANSF_LEN_MSK, reg) == 1)
+		*val = st->data[1];
+	else
+		*val = get_unaligned_be16(&st->data[1]);
+
+	return 0;
+}
+
+static int ad7293_spi_read(struct ad7293_state *st, unsigned int reg,
+			   u16 *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,
+			      u16 val)
+{
+	int ret;
+	unsigned int length = 1 + FIELD_GET(AD7293_TRANSF_LEN_MSK, reg);
+
+	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
+		put_unaligned_be16(val, &st->data[1]);
+
+	return spi_write(st->spi, &st->data[0], length);
+}
+
+static int ad7293_spi_write(struct ad7293_state *st, unsigned int reg,
+			    u16 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,
+				    u16 mask, u16 val)
+{
+	int ret;
+	u16 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,
+				  u16 mask, u16 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, u16 *range)
+{
+	int ret;
+	u16 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, u16 range)
+{
+	int ret;
+	unsigned int ch_msk = BIT(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, u16 *offset)
+{
+	if (ch < AD7293_TSENSE_MIN_OFFSET_CH)
+		return ad7293_spi_read(st, AD7293_REG_VIN0_OFFSET + ch, offset);
+	else if (ch < AD7293_ISENSE_MIN_OFFSET_CH)
+		return ad7293_spi_read(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - 4), offset);
+	else if (ch < AD7293_VOUT_MIN_OFFSET_CH)
+		return ad7293_spi_read(st, AD7293_REG_ISENSE0_OFFSET + (ch - 7), offset);
+	else if (ch <= AD7293_VOUT_MAX_OFFSET_CH)
+		return ad7293_spi_read(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - 11), offset);
+
+	return -EINVAL;
+}
+
+static int ad7293_set_offset(struct ad7293_state *st, unsigned int ch, u16 offset)
+{
+	if (ch < AD7293_TSENSE_MIN_OFFSET_CH)
+		return ad7293_spi_write(st, AD7293_REG_VIN0_OFFSET + ch, offset);
+	else if (ch < AD7293_ISENSE_MIN_OFFSET_CH)
+		return ad7293_spi_write(st, AD7293_REG_TSENSE_INT_OFFSET + (ch - AD7293_TSENSE_MIN_OFFSET_CH), offset);
+	else if (ch < AD7293_VOUT_MIN_OFFSET_CH)
+		return ad7293_spi_write(st, AD7293_REG_ISENSE0_OFFSET + (ch - AD7293_ISENSE_MIN_OFFSET_CH), offset);
+	else if (ch <= AD7293_VOUT_MAX_OFFSET_CH)
+		return ad7293_spi_update_bits(st, AD7293_REG_UNI_VOUT0_OFFSET + (ch - AD7293_VOUT_MIN_OFFSET_CH),
+						AD7293_REG_VOUT_OFFSET_MSK,
+						FIELD_PREP(AD7293_REG_VOUT_OFFSET_MSK, offset));
+
+	return -EINVAL;
+}
+
+static int ad7293_isense_set_scale(struct ad7293_state *st, unsigned int ch, u16 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_scale(struct ad7293_state *st, unsigned int ch, u16 *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, u16 raw)
+{
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	ret = __ad7293_spi_update_bits(st, AD7293_REG_DAC_EN, BIT(ch), BIT(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,
+			      u16 *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 = BIT(ch);
+
+		break;
+	case AD7293_ADC_TSENSE:
+		reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
+		reg_rd = AD7293_REG_TSENSE_INT + ch;
+		data_wr = BIT(ch);
+
+		break;
+	case AD7293_ADC_ISENSE:
+		reg_wr = AD7293_REG_ISENSEX_TSENSEX_SEQ;
+		reg_rd = AD7293_REG_ISENSE_0 + ch;
+		data_wr = BIT(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, BIT(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, BIT(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;
+	u16 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 + AD7293_VOUT_MIN_OFFSET_CH, &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 + AD7293_ISENSE_MIN_OFFSET_CH, &data);
+
+			break;
+		case IIO_TEMP:
+			ret = ad7293_get_offset(st, chan->channel + AD7293_TSENSE_MIN_OFFSET_CH, &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_CURRENT:
+			ret = ad7293_isense_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;
+		}
+	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 -EINVAL;
+
+			return ad7293_dac_write_raw(st, chan->channel, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			if (chan->output)
+				return ad7293_set_offset(st, chan->channel + AD7293_VOUT_MIN_OFFSET_CH, val);
+			else
+				return ad7293_set_offset(st, chan->channel, val);
+		case IIO_CURRENT:
+			return ad7293_set_offset(st, chan->channel + AD7293_ISENSE_MIN_OFFSET_CH, val);
+		case IIO_TEMP:
+			return ad7293_set_offset(st, chan->channel + AD7293_TSENSE_MIN_OFFSET_CH, val);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			return ad7293_adc_set_scale(st, chan->channel, val);
+		case IIO_CURRENT:
+			return ad7293_isense_set_scale(st, chan->channel, val);
+		default:
+			return -EINVAL;
+		}
+	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, (u16 *)read_val);
+	else
+		ret = ad7293_spi_write(st, reg, (u16)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 = dac_offset_table;
+		*type = IIO_VAL_INT;
+		*length = ARRAY_SIZE(dac_offset_table);
+
+		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SCALE:
+		*type = IIO_VAL_INT;
+
+		switch (chan->type) {
+		case IIO_VOLTAGE:
+			*vals = adc_range_table;
+			*length = ARRAY_SIZE(adc_range_table);
+			break;
+		case IIO_CURRENT:
+			*vals = isense_gain_table;
+			*length = ARRAY_SIZE(isense_gain_table);
+			break;
+		default:
+			return -EINVAL;
+		}
+
+		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_SCALE),			\
+	.info_mask_shared_by_type_available =			\
+		BIT(IIO_CHAN_INFO_SCALE)			\
+}
+
+#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_soft_reset(struct ad7293_state *st)
+{
+	int ret;
+
+	ret = __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x7293);
+	if (ret)
+		return ret;
+
+	return __ad7293_spi_write(st, AD7293_REG_SOFT_RESET, 0x0000);
+}
+
+static int ad7293_reset(struct ad7293_state *st)
+{
+	if (st->gpio_reset) {
+		gpiod_set_value(st->gpio_reset, 0);
+		usleep_range(100, 1000);
+		gpiod_set_value(st->gpio_reset, 1);
+		usleep_range(100, 1000);
+
+		return 0;
+	}
+
+	/* Perform a software reset */
+	return ad7293_soft_reset(st);
+}
+
+static int ad7293_properties_parse(struct ad7293_state *st)
+{
+	struct spi_device *spi = st->spi;
+
+	st->gpio_reset = devm_gpiod_get_optional(&st->spi->dev, "reset",
+						 GPIOD_OUT_HIGH);
+	if (IS_ERR(st->gpio_reset))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->gpio_reset),
+				     "failed to get the reset GPIO\n");
+
+	st->reg_avdd = devm_regulator_get(&spi->dev, "avdd");
+	if (IS_ERR(st->reg_avdd))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->reg_avdd),
+				     "failed to get the AVDD voltage\n");
+
+	st->reg_vdrive = devm_regulator_get(&spi->dev, "vdrive");
+	if (IS_ERR(st->reg_vdrive))
+		return dev_err_probe(&spi->dev, PTR_ERR(st->reg_vdrive),
+				     "failed to get the VDRIVE voltage\n");
+
+	return 0;
+}
+
+static void ad7293_reg_disable(void *data)
+{
+	regulator_disable(data);
+}
+
+static int ad7293_init(struct ad7293_state *st)
+{
+	int ret;
+	u16 chip_id;
+	struct spi_device *spi = st->spi;
+	unsigned int supply;
+
+	ret = ad7293_properties_parse(st);
+	if (ret)
+		return ret;
+
+	ret = ad7293_reset(st);
+	if (ret)
+		return ret;
+
+	ret = regulator_enable(st->reg_avdd);
+	if (ret) {
+		dev_err(&spi->dev, "Failed to enable specified AVDD Voltage!\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&spi->dev, ad7293_reg_disable,
+				       st->reg_avdd);
+	if (ret)
+		return ret;
+
+	ret = regulator_enable(st->reg_vdrive);
+	if (ret) {
+		dev_err(&spi->dev, "Failed to enable specified VDRIVE Voltage!\n");
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&spi->dev, ad7293_reg_disable,
+				       st->reg_vdrive);
+	if (ret)
+		return ret;
+
+	supply = regulator_get_voltage(st->reg_avdd);
+	if (supply > 5500000 || supply < 4500000)
+		return -EINVAL;
+
+	supply = regulator_get_voltage(st->reg_vdrive);
+	if (supply > 5500000 || supply < 1700000)
+		return -EINVAL;
+
+	/* 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