Re: [PATCH 2/2] staging: iio: adc: ad7192: move out of staging

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On Wed, 22 Jan 2020 16:37:00 +0200
Alexandru Tachici <alexandru.tachici@xxxxxxxxxx> wrote:

> Move ad7192 ADC driver out of staging into mainline.
> 
> Signed-off-by: Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
Hi Alexandru,

Great to see some movement on this one.  There are a few more things
that need cleaning up I think before we move it out.

The iio_chan_spec handling in particular seems more complex than
it needs to be.

Also, note the observation that the ad_sd core handling of single
reads looks racy to me.

See inline

Thanks,

Jonathan

> ---
>  MAINTAINERS                      |    9 +
>  drivers/iio/adc/Kconfig          |   12 +
>  drivers/iio/adc/Makefile         |    1 +
>  drivers/iio/adc/ad7192.c         | 1022 ++++++++++++++++++++++++++++++
>  drivers/staging/iio/adc/Kconfig  |   12 -
>  drivers/staging/iio/adc/Makefile |    1 -
>  drivers/staging/iio/adc/ad7192.c | 1022 ------------------------------
>  7 files changed, 1044 insertions(+), 1035 deletions(-)
>  create mode 100644 drivers/iio/adc/ad7192.c
>  delete mode 100644 drivers/staging/iio/adc/ad7192.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e699fe378e71..d58e2fa0e686 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -922,6 +922,15 @@ S:	Supported
>  F:	drivers/iio/adc/ad7124.c
>  F:	Documentation/devicetree/bindings/iio/adc/adi,ad7124.yaml
>  
> +ANALOG DEVICES INC AD7192 DRIVER
> +M:	Alexandru Tachici <alexandru.tachici@xxxxxxxxxx>
> +L:	linux-iio@xxxxxxxxxxxxxxx
> +W:	http://ez.analog.com/community/linux-device-drivers
> +S:	Supported
> +F:	drivers/iio/adc/ad7192.c
> +F:	./Documentation/devicetree/bindings/iio/adc/adi,ad7192.yaml
> +
One blank line only.
> +
>  ANALOG DEVICES INC AD7292 DRIVER
>  M:	Marcelo Schmitt <marcelo.schmitt1@xxxxxxxxx>
>  L:	linux-iio@xxxxxxxxxxxxxxx
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 82e33082958c..f4da821c4022 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -39,6 +39,18 @@ config AD7124
>  	  To compile this driver as a module, choose M here: the module will be
>  	  called ad7124.
>  
> +config AD7192
> +	tristate "Analog Devices AD7190 AD7192 AD7193 AD7195 ADC driver"
> +	depends on SPI
> +	select AD_SIGMA_DELTA
> +	help
> +	  Say yes here to build support for Analog Devices AD7190,
> +	  AD7192, AD7193 or AD7195 SPI analog to digital converters (ADC).
> +	  If unsure, say N (but it's safe to say "Y").
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ad7192.
> +
>  config AD7266
>  	tristate "Analog Devices AD7265/AD7266 ADC driver"
>  	depends on SPI_MASTER
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 919228900df9..8462455b4228 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -8,6 +8,7 @@ obj-$(CONFIG_AB8500_GPADC) += ab8500-gpadc.o
>  obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
>  obj-$(CONFIG_AD7091R5) += ad7091r5.o ad7091r-base.o
>  obj-$(CONFIG_AD7124) += ad7124.o
> +obj-$(CONFIG_AD7192) += ad7192.o
>  obj-$(CONFIG_AD7266) += ad7266.o
>  obj-$(CONFIG_AD7291) += ad7291.o
>  obj-$(CONFIG_AD7292) += ad7292.o
> diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c
> new file mode 100644
> index 000000000000..bf3e2a9cc07f
> --- /dev/null
> +++ b/drivers/iio/adc/ad7192.c
> @@ -0,0 +1,1022 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AD7190 AD7192 AD7193 AD7195 SPI ADC driver
> + *
> + * Copyright 2011-2015 Analog Devices Inc.
> + */
> +
> +#include <linux/interrupt.h>
> +#include <linux/clk.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/slab.h>
> +#include <linux/sysfs.h>
> +#include <linux/spi/spi.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/err.h>
> +#include <linux/sched.h>
> +#include <linux/delay.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/iio/adc/ad_sigma_delta.h>
> +
> +/* Registers */
> +#define AD7192_REG_COMM		0 /* Communications Register (WO, 8-bit) */
> +#define AD7192_REG_STAT		0 /* Status Register	     (RO, 8-bit) */
> +#define AD7192_REG_MODE		1 /* Mode Register	     (RW, 24-bit */
> +#define AD7192_REG_CONF		2 /* Configuration Register  (RW, 24-bit) */
> +#define AD7192_REG_DATA		3 /* Data Register	     (RO, 24/32-bit) */
> +#define AD7192_REG_ID		4 /* ID Register	     (RO, 8-bit) */
> +#define AD7192_REG_GPOCON	5 /* GPOCON Register	     (RO, 8-bit) */
> +#define AD7192_REG_OFFSET	6 /* Offset Register	     (RW, 16-bit */
> +				  /* (AD7792)/24-bit (AD7192)) */
> +#define AD7192_REG_FULLSALE	7 /* Full-Scale Register */
> +				  /* (RW, 16-bit (AD7792)/24-bit (AD7192)) */
> +
> +/* Communications Register Bit Designations (AD7192_REG_COMM) */
> +#define AD7192_COMM_WEN		BIT(7) /* Write Enable */
> +#define AD7192_COMM_WRITE	0 /* Write Operation */
> +#define AD7192_COMM_READ	BIT(6) /* Read Operation */
> +#define AD7192_COMM_ADDR(x)	(((x) & 0x7) << 3) /* Register Address */
> +#define AD7192_COMM_CREAD	BIT(2) /* Continuous Read of Data Register */
> +
> +/* Status Register Bit Designations (AD7192_REG_STAT) */
> +#define AD7192_STAT_RDY		BIT(7) /* Ready */
> +#define AD7192_STAT_ERR		BIT(6) /* Error (Overrange, Underrange) */
> +#define AD7192_STAT_NOREF	BIT(5) /* Error no external reference */
> +#define AD7192_STAT_PARITY	BIT(4) /* Parity */
> +#define AD7192_STAT_CH3		BIT(2) /* Channel 3 */
> +#define AD7192_STAT_CH2		BIT(1) /* Channel 2 */
> +#define AD7192_STAT_CH1		BIT(0) /* Channel 1 */
> +
> +/* Mode Register Bit Designations (AD7192_REG_MODE) */
> +#define AD7192_MODE_SEL(x)	(((x) & 0x7) << 21) /* Operation Mode Select */
> +#define AD7192_MODE_SEL_MASK	(0x7 << 21) /* Operation Mode Select Mask */
> +#define AD7192_MODE_DAT_STA	BIT(20) /* Status Register transmission */
> +#define AD7192_MODE_CLKSRC(x)	(((x) & 0x3) << 18) /* Clock Source Select */
> +#define AD7192_MODE_SINC3	BIT(15) /* SINC3 Filter Select */
> +#define AD7192_MODE_ACX		BIT(14) /* AC excitation enable(AD7195 only)*/
> +#define AD7192_MODE_ENPAR	BIT(13) /* Parity Enable */
> +#define AD7192_MODE_CLKDIV	BIT(12) /* Clock divide by 2 (AD7190/2 only)*/
> +#define AD7192_MODE_SCYCLE	BIT(11) /* Single cycle conversion */
> +#define AD7192_MODE_REJ60	BIT(10) /* 50/60Hz notch filter */
> +#define AD7192_MODE_RATE(x)	((x) & 0x3FF) /* Filter Update Rate Select */
> +
> +/* Mode Register: AD7192_MODE_SEL options */
> +#define AD7192_MODE_CONT		0 /* Continuous Conversion Mode */
> +#define AD7192_MODE_SINGLE		1 /* Single Conversion Mode */
> +#define AD7192_MODE_IDLE		2 /* Idle Mode */
> +#define AD7192_MODE_PWRDN		3 /* Power-Down Mode */
> +#define AD7192_MODE_CAL_INT_ZERO	4 /* Internal Zero-Scale Calibration */
> +#define AD7192_MODE_CAL_INT_FULL	5 /* Internal Full-Scale Calibration */
> +#define AD7192_MODE_CAL_SYS_ZERO	6 /* System Zero-Scale Calibration */
> +#define AD7192_MODE_CAL_SYS_FULL	7 /* System Full-Scale Calibration */
> +
> +/* Mode Register: AD7192_MODE_CLKSRC options */
> +#define AD7192_CLK_EXT_MCLK1_2		0 /* External 4.92 MHz Clock connected*/
> +					  /* from MCLK1 to MCLK2 */
> +#define AD7192_CLK_EXT_MCLK2		1 /* External Clock applied to MCLK2 */
> +#define AD7192_CLK_INT			2 /* Internal 4.92 MHz Clock not */
> +					  /* available at the MCLK2 pin */
> +#define AD7192_CLK_INT_CO		3 /* Internal 4.92 MHz Clock available*/
> +					  /* at the MCLK2 pin */
> +
> +/* Configuration Register Bit Designations (AD7192_REG_CONF) */
> +
> +#define AD7192_CONF_CHOP	BIT(23) /* CHOP enable */
> +#define AD7192_CONF_REFSEL	BIT(20) /* REFIN1/REFIN2 Reference Select */
> +#define AD7192_CONF_CHAN(x)	((x) << 8) /* Channel select */
> +#define AD7192_CONF_CHAN_MASK	(0x7FF << 8) /* Channel select mask */
> +#define AD7192_CONF_BURN	BIT(7) /* Burnout current enable */
> +#define AD7192_CONF_REFDET	BIT(6) /* Reference detect enable */
> +#define AD7192_CONF_BUF		BIT(4) /* Buffered Mode Enable */
> +#define AD7192_CONF_UNIPOLAR	BIT(3) /* Unipolar/Bipolar Enable */
> +#define AD7192_CONF_GAIN(x)	((x) & 0x7) /* Gain Select */
> +
> +#define AD7192_CH_AIN1P_AIN2M	BIT(0) /* AIN1(+) - AIN2(-) */
> +#define AD7192_CH_AIN3P_AIN4M	BIT(1) /* AIN3(+) - AIN4(-) */
> +#define AD7192_CH_TEMP		BIT(2) /* Temp Sensor */
> +#define AD7192_CH_AIN2P_AIN2M	BIT(3) /* AIN2(+) - AIN2(-) */
> +#define AD7192_CH_AIN1		BIT(4) /* AIN1 - AINCOM */
> +#define AD7192_CH_AIN2		BIT(5) /* AIN2 - AINCOM */
> +#define AD7192_CH_AIN3		BIT(6) /* AIN3 - AINCOM */
> +#define AD7192_CH_AIN4		BIT(7) /* AIN4 - AINCOM */
> +
> +#define AD7193_CH_AIN1P_AIN2M	0x001  /* AIN1(+) - AIN2(-) */
> +#define AD7193_CH_AIN3P_AIN4M	0x002  /* AIN3(+) - AIN4(-) */
> +#define AD7193_CH_AIN5P_AIN6M	0x004  /* AIN5(+) - AIN6(-) */
> +#define AD7193_CH_AIN7P_AIN8M	0x008  /* AIN7(+) - AIN8(-) */
> +#define AD7193_CH_TEMP		0x100 /* Temp senseor */
> +#define AD7193_CH_AIN2P_AIN2M	0x200 /* AIN2(+) - AIN2(-) */
> +#define AD7193_CH_AIN1		0x401 /* AIN1 - AINCOM */
> +#define AD7193_CH_AIN2		0x402 /* AIN2 - AINCOM */
> +#define AD7193_CH_AIN3		0x404 /* AIN3 - AINCOM */
> +#define AD7193_CH_AIN4		0x408 /* AIN4 - AINCOM */
> +#define AD7193_CH_AIN5		0x410 /* AIN5 - AINCOM */
> +#define AD7193_CH_AIN6		0x420 /* AIN6 - AINCOM */
> +#define AD7193_CH_AIN7		0x440 /* AIN7 - AINCOM */
> +#define AD7193_CH_AIN8		0x480 /* AIN7 - AINCOM */
> +#define AD7193_CH_AINCOM	0x600 /* AINCOM - AINCOM */
> +
> +/* ID Register Bit Designations (AD7192_REG_ID) */
> +#define ID_AD7190		0x4
> +#define ID_AD7192		0x0
> +#define ID_AD7193		0x2
> +#define ID_AD7195		0x6
> +#define AD7192_ID_MASK		0x0F
> +
> +/* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */
> +#define AD7192_GPOCON_BPDSW	BIT(6) /* Bridge power-down switch enable */
> +#define AD7192_GPOCON_GP32EN	BIT(5) /* Digital Output P3 and P2 enable */
> +#define AD7192_GPOCON_GP10EN	BIT(4) /* Digital Output P1 and P0 enable */
> +#define AD7192_GPOCON_P3DAT	BIT(3) /* P3 state */
> +#define AD7192_GPOCON_P2DAT	BIT(2) /* P2 state */
> +#define AD7192_GPOCON_P1DAT	BIT(1) /* P1 state */
> +#define AD7192_GPOCON_P0DAT	BIT(0) /* P0 state */
> +
> +#define AD7192_EXT_FREQ_MHZ_MIN	2457600
> +#define AD7192_EXT_FREQ_MHZ_MAX	5120000
> +#define AD7192_INT_FREQ_MHZ	4915200
> +
> +#define AD7192_NO_SYNC_FILTER	1
> +#define AD7192_SYNC3_FILTER	3
> +#define AD7192_SYNC4_FILTER	4
> +
> +/* NOTE:
> + * The AD7190/2/5 features a dual use data out ready DOUT/RDY output.
> + * In order to avoid contentions on the SPI bus, it's therefore necessary
> + * to use spi bus locking.
> + *
> + * The DOUT/RDY output must also be wired to an interrupt capable GPIO.
> + */
> +
> +enum {
> +   AD7192_SYSCALIB_ZERO_SCALE,
> +   AD7192_SYSCALIB_FULL_SCALE,
> +};
> +
> +struct ad7192_state {
> +	struct regulator		*avdd;
> +	struct regulator		*dvdd;
> +	struct clk			*mclk;
> +	u16				int_vref_mv;
> +	u32				fclk;
> +	u32				f_order;
> +	u32				mode;
> +	u32				conf;
> +	u32				scale_avail[8][2];
> +	u8				gpocon;
> +	u8				devid;
> +	u8				clock_sel;
> +	struct mutex			lock;	/* protect sensor state */
> +	u8				syscalib_mode[8];
> +
> +	struct ad_sigma_delta		sd;
> +};
> +
> +static const char * const ad7192_syscalib_modes[] = {
> +	[AD7192_SYSCALIB_ZERO_SCALE] = "zero_scale",
> +	[AD7192_SYSCALIB_FULL_SCALE] = "full_scale",
> +};
> +
> +static int ad7192_set_syscalib_mode(struct iio_dev *indio_dev,
> +				    const struct iio_chan_spec *chan,
> +				    unsigned int mode)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	st->syscalib_mode[chan->channel] = mode;
> +
> +	return 0;
> +}
> +
> +static int ad7192_get_syscalib_mode(struct iio_dev *indio_dev,
> +				    const struct iio_chan_spec *chan)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	return st->syscalib_mode[chan->channel];
> +}
> +
> +static ssize_t ad7192_write_syscalib(struct iio_dev *indio_dev,
> +				     uintptr_t private,
> +				     const struct iio_chan_spec *chan,
> +				     const char *buf, size_t len)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	bool sys_calib;
> +	int ret, temp;
> +
> +	ret = strtobool(buf, &sys_calib);
> +	if (ret)
> +		return ret;
> +
> +	temp = st->syscalib_mode[chan->channel];
> +	if (sys_calib) {
> +		if (temp == AD7192_SYSCALIB_ZERO_SCALE)
> +			ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_ZERO,
> +					      chan->address);
> +		else
> +			ret = ad_sd_calibrate(&st->sd, AD7192_MODE_CAL_SYS_FULL,
> +					      chan->address);
> +	}
> +
> +	return ret ? ret : len;
> +}
> +
> +static const struct iio_enum ad7192_syscalib_mode_enum = {
> +	.items = ad7192_syscalib_modes,
> +	.num_items = ARRAY_SIZE(ad7192_syscalib_modes),
> +	.set = ad7192_set_syscalib_mode,
> +	.get = ad7192_get_syscalib_mode
> +};
> +
> +static const struct iio_chan_spec_ext_info ad7192_calibsys_ext_info[] = {
> +	{
> +		.name = "sys_calibration",
> +		.write = ad7192_write_syscalib,
> +		.shared = IIO_SEPARATE,
> +	},
> +	IIO_ENUM("sys_calibration_mode", IIO_SEPARATE,
> +		 &ad7192_syscalib_mode_enum),
> +	IIO_ENUM_AVAILABLE("sys_calibration_mode", &ad7192_syscalib_mode_enum),
> +	{}
> +};
> +
> +static struct ad7192_state *ad_sigma_delta_to_ad7192(struct ad_sigma_delta *sd)
> +{
> +	return container_of(sd, struct ad7192_state, sd);
> +}
> +
> +static int ad7192_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
> +{
> +	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
> +
> +	st->conf &= ~AD7192_CONF_CHAN_MASK;
> +	st->conf |= AD7192_CONF_CHAN(channel);
> +
> +	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
> +}
> +
> +static int ad7192_set_mode(struct ad_sigma_delta *sd,
> +			   enum ad_sigma_delta_mode mode)
> +{
> +	struct ad7192_state *st = ad_sigma_delta_to_ad7192(sd);
> +
> +	st->mode &= ~AD7192_MODE_SEL_MASK;
> +	st->mode |= AD7192_MODE_SEL(mode);
> +
> +	return ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
> +}
> +
> +static const struct ad_sigma_delta_info ad7192_sigma_delta_info = {
> +	.set_channel = ad7192_set_channel,
> +	.set_mode = ad7192_set_mode,
> +	.has_registers = true,
> +	.addr_shift = 3,
> +	.read_mask = BIT(6),
> +};
> +
> +static const struct ad_sd_calib_data ad7192_calib_arr[8] = {
> +	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN1},
> +	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN1},
> +	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN2},
> +	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN2},
> +	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN3},
> +	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN3},
> +	{AD7192_MODE_CAL_INT_ZERO, AD7192_CH_AIN4},
> +	{AD7192_MODE_CAL_INT_FULL, AD7192_CH_AIN4}
> +};
> +
> +static int ad7192_calibrate_all(struct ad7192_state *st)
> +{
> +	return ad_sd_calibrate_all(&st->sd, ad7192_calib_arr,
> +				   ARRAY_SIZE(ad7192_calib_arr));
> +}
> +
> +static inline bool ad7192_valid_external_frequency(u32 freq)
> +{
> +	return (freq >= AD7192_EXT_FREQ_MHZ_MIN &&
> +		freq <= AD7192_EXT_FREQ_MHZ_MAX);
> +}
> +
> +static int ad7192_of_clock_select(struct ad7192_state *st)
> +{
> +	struct device_node *np = st->sd.spi->dev.of_node;
> +	unsigned int clock_sel;
> +
> +	clock_sel = AD7192_CLK_INT;
> +
> +	/* use internal clock */
> +	if (PTR_ERR(st->mclk) == -ENOENT) {
> +		if (of_property_read_bool(np, "adi,int-clock-output-enable"))
> +			clock_sel = AD7192_CLK_INT_CO;
> +	} else {
> +		if (of_property_read_bool(np, "adi,clock-xtal"))
> +			clock_sel = AD7192_CLK_EXT_MCLK1_2;
> +		else
> +			clock_sel = AD7192_CLK_EXT_MCLK2;
> +	}
> +
> +	return clock_sel;
> +}
> +
> +static int ad7192_setup(struct ad7192_state *st, struct device_node *np)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(st->sd.spi);
> +	bool rej60_en, refin2_en;
> +	bool buf_en, bipolar, burnout_curr_en;
> +	unsigned long long scale_uv;
> +	int i, ret, id;
> +
> +	/* reset the serial interface */
> +	ret = ad_sd_reset(&st->sd, 48);
> +	if (ret < 0)
> +		return ret;
> +	usleep_range(500, 1000); /* Wait for at least 500us */
> +
> +	/* write/read test for device presence */
> +	ret = ad_sd_read_reg(&st->sd, AD7192_REG_ID, 1, &id);
> +	if (ret)
> +		return ret;
> +
> +	id &= AD7192_ID_MASK;
> +
> +	if (id != st->devid)
> +		dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n",
> +			 id);
> +
> +	st->mode = AD7192_MODE_SEL(AD7192_MODE_IDLE) |
> +		AD7192_MODE_CLKSRC(st->clock_sel) |
> +		AD7192_MODE_RATE(480);
> +
> +	st->conf = AD7192_CONF_GAIN(0);
> +
> +	rej60_en = of_property_read_bool(np, "adi,rejection-60-Hz-enable");
> +	if (rej60_en)
> +		st->mode |= AD7192_MODE_REJ60;
> +
> +	refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable");
> +	if (refin2_en && st->devid != ID_AD7195)
> +		st->conf |= AD7192_CONF_REFSEL;
> +
> +	st->conf &= ~AD7192_CONF_CHOP;
> +	st->f_order = AD7192_NO_SYNC_FILTER;
> +
> +	buf_en = of_property_read_bool(np, "adi,buffer-enable");
> +	if (buf_en)
> +		st->conf |= AD7192_CONF_BUF;
> +
> +	bipolar = of_property_read_bool(np, "bipolar");
> +	if (!bipolar)
> +		st->conf |= AD7192_CONF_UNIPOLAR;
> +
> +	burnout_curr_en = of_property_read_bool(np,
> +						"adi,burnout-currents-enable");
> +	if (burnout_curr_en && buf_en) {
> +		st->conf |= AD7192_CONF_BURN;
> +	} else if (burnout_curr_en) {
> +		dev_warn(&st->sd.spi->dev,
> +			 "Can't enable burnout currents: see CHOP or buffer\n");
> +	}
> +
> +	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
> +	if (ret)
> +		return ret;
> +
> +	ret = ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
> +	if (ret)
> +		return ret;
> +
> +	ret = ad7192_calibrate_all(st);
> +	if (ret)
> +		return ret;
> +
> +	/* Populate available ADC input ranges */
> +	for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++) {
> +		scale_uv = ((u64)st->int_vref_mv * 100000000)
> +			>> (indio_dev->channels[0].scan_type.realbits -
> +			((st->conf & AD7192_CONF_UNIPOLAR) ? 0 : 1));
> +		scale_uv >>= i;
> +
> +		st->scale_avail[i][1] = do_div(scale_uv, 100000000) * 10;
> +		st->scale_avail[i][0] = scale_uv;
> +	}
> +
> +	return 0;
> +}
> +
> +static ssize_t ad7192_show_ac_excitation(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", !!(st->mode & AD7192_MODE_ACX));
> +}
> +
> +static ssize_t ad7192_show_bridge_switch(struct device *dev,
> +					 struct device_attribute *attr,
> +					 char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	return sprintf(buf, "%d\n", !!(st->gpocon & AD7192_GPOCON_BPDSW));
> +}
> +
> +static ssize_t ad7192_set(struct device *dev,
> +			  struct device_attribute *attr,
> +			  const char *buf,
> +			  size_t len)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> +	int ret;
> +	bool val;
> +
> +	ret = strtobool(buf, &val);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	switch ((u32)this_attr->address) {
> +	case AD7192_REG_GPOCON:
> +		if (val)
> +			st->gpocon |= AD7192_GPOCON_BPDSW;
> +		else
> +			st->gpocon &= ~AD7192_GPOCON_BPDSW;
> +
> +		ad_sd_write_reg(&st->sd, AD7192_REG_GPOCON, 1, st->gpocon);
> +		break;
> +	case AD7192_REG_MODE:
> +		if (val)
> +			st->mode |= AD7192_MODE_ACX;
> +		else
> +			st->mode &= ~AD7192_MODE_ACX;
> +
> +		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	iio_device_release_direct_mode(indio_dev);
> +
> +	return ret ? ret : len;
> +}
> +
> +static void ad7192_get_available_filter_freq(struct ad7192_state *st,
> +						    int *freq)
> +{
> +	unsigned int fadc;
> +
> +	/* Formulas for filter at page 25 of the datasheet */
> +	fadc = DIV_ROUND_CLOSEST(st->fclk,
> +				 AD7192_SYNC4_FILTER * AD7192_MODE_RATE(st->mode));
> +	freq[0] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
> +
> +	fadc = DIV_ROUND_CLOSEST(st->fclk,
> +				 AD7192_SYNC3_FILTER * AD7192_MODE_RATE(st->mode));
> +	freq[1] = DIV_ROUND_CLOSEST(fadc * 240, 1024);
> +
> +	fadc = DIV_ROUND_CLOSEST(st->fclk, AD7192_MODE_RATE(st->mode));
> +	freq[2] = DIV_ROUND_CLOSEST(fadc * 230, 1024);
> +	freq[3] = DIV_ROUND_CLOSEST(fadc * 272, 1024);
> +}
> +
> +static ssize_t ad7192_show_filter_avail(struct device *dev,
> +					struct device_attribute *attr,
> +					char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	unsigned int freq_avail[4], i;
> +	size_t len = 0;
> +
> +	ad7192_get_available_filter_freq(st, freq_avail);
> +
> +	for (i = 0; i < ARRAY_SIZE(freq_avail); i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len,
> +				 "%d.%d ", freq_avail[i] / 1000,
> +				 freq_avail[i] % 1000);
> +
> +	buf[len - 1] = '\n';
> +
> +	return len;
> +}
> +
> +static IIO_DEVICE_ATTR(filter_low_pass_3db_frequency_available,
> +		       0444, ad7192_show_filter_avail, NULL, 0);
> +
> +static IIO_DEVICE_ATTR(bridge_switch_en, 0644,
> +		       ad7192_show_bridge_switch, ad7192_set,
> +		       AD7192_REG_GPOCON);
> +
> +static IIO_DEVICE_ATTR(ac_excitation_en, 0644,
> +		       ad7192_show_ac_excitation, ad7192_set,
> +		       AD7192_REG_MODE);
> +
> +static struct attribute *ad7192_attributes[] = {
> +	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
> +	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
> +	&iio_dev_attr_ac_excitation_en.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group ad7192_attribute_group = {
> +	.attrs = ad7192_attributes,
> +};
> +
> +static struct attribute *ad7195_attributes[] = {
> +	&iio_dev_attr_filter_low_pass_3db_frequency_available.dev_attr.attr,
> +	&iio_dev_attr_bridge_switch_en.dev_attr.attr,
> +	NULL
> +};
> +
> +static const struct attribute_group ad7195_attribute_group = {
> +	.attrs = ad7195_attributes,
> +};
> +
> +static unsigned int ad7192_get_temp_scale(bool unipolar)
> +{
> +	return unipolar ? 2815 * 2 : 2815;
> +}
> +
> +static int ad7192_set_3db_filter_freq(struct ad7192_state *st,
> +				      int val, int val2)
> +{
> +	int freq_avail[4], i, ret, freq;
> +	unsigned int diff_new, diff_old;
> +	int idx = 0;
> +
> +	diff_old = U32_MAX;
> +	freq = val * 1000 + val2;
> +
> +	ad7192_get_available_filter_freq(st, freq_avail);
> +
> +	for (i = 0; i < ARRAY_SIZE(freq_avail); i++) {
> +		diff_new = abs(freq - freq_avail[i]);
> +		if (diff_new < diff_old) {
> +			diff_old = diff_new;
> +			idx = i;
> +		}
> +	}
> +
> +	switch (idx) {
> +	case 0:
> +		st->f_order = AD7192_SYNC4_FILTER;
> +		st->mode &= ~AD7192_MODE_SINC3;
> +
> +		st->conf |= AD7192_CONF_CHOP;
> +		break;
> +	case 1:
> +		st->f_order = AD7192_SYNC3_FILTER;
> +		st->mode |= AD7192_MODE_SINC3;
> +
> +		st->conf |= AD7192_CONF_CHOP;
> +		break;
> +	case 2:
> +		st->f_order = AD7192_NO_SYNC_FILTER;
> +		st->mode &= ~AD7192_MODE_SINC3;
> +
> +		st->conf &= ~AD7192_CONF_CHOP;
> +		break;
> +	case 3:
> +		st->f_order = AD7192_NO_SYNC_FILTER;
> +		st->mode |= AD7192_MODE_SINC3;
> +
> +		st->conf &= ~AD7192_CONF_CHOP;
> +		break;
> +	}
> +
> +	ret = ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
> +	if (ret < 0)
> +		return ret;
> +
> +	return ad_sd_write_reg(&st->sd, AD7192_REG_CONF, 3, st->conf);
> +}
> +
> +static int ad7192_get_3db_filter_freq(struct ad7192_state *st)
> +{
> +	unsigned int fadc;
> +
> +	fadc = DIV_ROUND_CLOSEST(st->fclk,
> +				 st->f_order * AD7192_MODE_RATE(st->mode));
> +
> +	if (st->conf & AD7192_CONF_CHOP)
> +		return DIV_ROUND_CLOSEST(fadc * 240, 1024);
> +	if (st->mode & AD7192_MODE_SINC3)
> +		return DIV_ROUND_CLOSEST(fadc * 272, 1024);
> +	else
> +		return DIV_ROUND_CLOSEST(fadc * 230, 1024);
> +}
> +
> +static int ad7192_read_raw(struct iio_dev *indio_dev,
> +			   struct iio_chan_spec const *chan,
> +			   int *val,
> +			   int *val2,
> +			   long m)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	bool unipolar = !!(st->conf & AD7192_CONF_UNIPOLAR);
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_RAW:
> +		return ad_sigma_delta_single_conversion(indio_dev, chan, val);

Hmm. I just wondered where the enforcement of not clashing with buffered
mode here was.  Looking at ad_sigma_delta_single_conversion it seems to have
a racy check on whether we are in buffered mode.  If possible that should
be changed to the claim direct mode route to prevent race conditions.

Obviously not directly related to this patch though.

> +	case IIO_CHAN_INFO_SCALE:
> +		switch (chan->type) {
> +		case IIO_VOLTAGE:
> +			mutex_lock(&st->lock);
> +			*val = st->scale_avail[AD7192_CONF_GAIN(st->conf)][0];
> +			*val2 = st->scale_avail[AD7192_CONF_GAIN(st->conf)][1];
> +			mutex_unlock(&st->lock);
> +			return IIO_VAL_INT_PLUS_NANO;
> +		case IIO_TEMP:
> +			*val = 0;
> +			*val2 = 1000000000 / ad7192_get_temp_scale(unipolar);
> +			return IIO_VAL_INT_PLUS_NANO;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_OFFSET:
> +		if (!unipolar)
> +			*val = -(1 << (chan->scan_type.realbits - 1));
> +		else
> +			*val = 0;
> +		/* Kelvin to Celsius */
> +		if (chan->type == IIO_TEMP)
> +			*val -= 273 * ad7192_get_temp_scale(unipolar);
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		*val = st->fclk /
> +			(st->f_order * 1024 * AD7192_MODE_RATE(st->mode));
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		*val = ad7192_get_3db_filter_freq(st);
> +		*val2 = 1000;
> +		return IIO_VAL_FRACTIONAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int ad7192_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val,
> +			    int val2,
> +			    long mask)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	int ret, i, div;
> +	unsigned int tmp;
> +
> +	ret = iio_device_claim_direct_mode(indio_dev);
> +	if (ret)
> +		return ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = -EINVAL;
> +		mutex_lock(&st->lock);
> +		for (i = 0; i < ARRAY_SIZE(st->scale_avail); i++)
> +			if (val2 == st->scale_avail[i][1]) {
> +				ret = 0;
> +				tmp = st->conf;
> +				st->conf &= ~AD7192_CONF_GAIN(-1);
> +				st->conf |= AD7192_CONF_GAIN(i);
> +				if (tmp == st->conf)
> +					break;
> +				ad_sd_write_reg(&st->sd, AD7192_REG_CONF,
> +						3, st->conf);
> +				ad7192_calibrate_all(st);
> +				break;
> +			}
> +		mutex_unlock(&st->lock);
> +		break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		if (!val) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
> +		div = st->fclk / (val * st->f_order * 1024);
> +		if (div < 1 || div > 1023) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
> +		st->mode &= ~AD7192_MODE_RATE(-1);
> +		st->mode |= AD7192_MODE_RATE(div);
> +		ad_sd_write_reg(&st->sd, AD7192_REG_MODE, 3, st->mode);
> +		break;
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		ret = ad7192_set_3db_filter_freq(st, val, val2 / 1000);
> +		break;
> +	default:
> +		ret = -EINVAL;
> +	}
> +
> +	iio_device_release_direct_mode(indio_dev);
> +
> +	return ret;
> +}
> +
> +static int ad7192_write_raw_get_fmt(struct iio_dev *indio_dev,
> +				    struct iio_chan_spec const *chan,
> +				    long mask)
> +{
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		return IIO_VAL_INT_PLUS_NANO;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY:
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int ad7192_read_avail(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     const int **vals, int *type, int *length,
> +			     long mask)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SCALE:
> +		*vals = (int *)st->scale_avail;
> +		*type = IIO_VAL_INT_PLUS_NANO;
> +		/* Values are stored in a 2D matrix  */
> +		*length = ARRAY_SIZE(st->scale_avail) * 2;
> +
> +		return IIO_AVAIL_LIST;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info ad7192_info = {
> +	.read_raw = ad7192_read_raw,
> +	.write_raw = ad7192_write_raw,
> +	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
> +	.read_avail = ad7192_read_avail,
> +	.attrs = &ad7192_attribute_group,
> +	.validate_trigger = ad_sd_validate_trigger,
> +};
> +
> +static const struct iio_info ad7195_info = {
> +	.read_raw = ad7192_read_raw,
> +	.write_raw = ad7192_write_raw,
> +	.write_raw_get_fmt = ad7192_write_raw_get_fmt,
> +	.read_avail = ad7192_read_avail,
> +	.attrs = &ad7195_attribute_group,
> +	.validate_trigger = ad_sd_validate_trigger,
> +};
> +
> +static const struct iio_chan_spec ad7192_channels[] = {
> +	AD_SD_DIFF_CHANNEL(0, 1, 2, AD7192_CH_AIN1P_AIN2M, 24, 32, 0),
> +	AD_SD_DIFF_CHANNEL(1, 3, 4, AD7192_CH_AIN3P_AIN4M, 24, 32, 0),
> +	AD_SD_TEMP_CHANNEL(2, AD7192_CH_TEMP, 24, 32, 0),
> +	AD_SD_SHORTED_CHANNEL(3, 2, AD7192_CH_AIN2P_AIN2M, 24, 32, 0),
> +	AD_SD_CHANNEL(4, 1, AD7192_CH_AIN1, 24, 32, 0),
> +	AD_SD_CHANNEL(5, 2, AD7192_CH_AIN2, 24, 32, 0),
> +	AD_SD_CHANNEL(6, 3, AD7192_CH_AIN3, 24, 32, 0),
> +	AD_SD_CHANNEL(7, 4, AD7192_CH_AIN4, 24, 32, 0),
> +	IIO_CHAN_SOFT_TIMESTAMP(8),
> +};
> +
> +static const struct iio_chan_spec ad7193_channels[] = {
> +	AD_SD_DIFF_CHANNEL(0, 1, 2, AD7193_CH_AIN1P_AIN2M, 24, 32, 0),
> +	AD_SD_DIFF_CHANNEL(1, 3, 4, AD7193_CH_AIN3P_AIN4M, 24, 32, 0),
> +	AD_SD_DIFF_CHANNEL(2, 5, 6, AD7193_CH_AIN5P_AIN6M, 24, 32, 0),
> +	AD_SD_DIFF_CHANNEL(3, 7, 8, AD7193_CH_AIN7P_AIN8M, 24, 32, 0),
> +	AD_SD_TEMP_CHANNEL(4, AD7193_CH_TEMP, 24, 32, 0),
> +	AD_SD_SHORTED_CHANNEL(5, 2, AD7193_CH_AIN2P_AIN2M, 24, 32, 0),
> +	AD_SD_CHANNEL(6, 1, AD7193_CH_AIN1, 24, 32, 0),
> +	AD_SD_CHANNEL(7, 2, AD7193_CH_AIN2, 24, 32, 0),
> +	AD_SD_CHANNEL(8, 3, AD7193_CH_AIN3, 24, 32, 0),
> +	AD_SD_CHANNEL(9, 4, AD7193_CH_AIN4, 24, 32, 0),
> +	AD_SD_CHANNEL(10, 5, AD7193_CH_AIN5, 24, 32, 0),
> +	AD_SD_CHANNEL(11, 6, AD7193_CH_AIN6, 24, 32, 0),
> +	AD_SD_CHANNEL(12, 7, AD7193_CH_AIN7, 24, 32, 0),
> +	AD_SD_CHANNEL(13, 8, AD7193_CH_AIN8, 24, 32, 0),
> +	IIO_CHAN_SOFT_TIMESTAMP(14),
> +};
> +
> +static int ad7192_channels_config(struct iio_dev *indio_dev)
> +{
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +	const struct iio_chan_spec *channels;
> +	struct iio_chan_spec *chan;
> +	int i;
> +
> +	switch (st->devid) {
> +	case ID_AD7193:
> +		channels = ad7193_channels;
> +		indio_dev->num_channels = ARRAY_SIZE(ad7193_channels);
> +		break;
> +	default:
> +		channels = ad7192_channels;
> +		indio_dev->num_channels = ARRAY_SIZE(ad7192_channels);
> +		break;
> +	}
> +
> +	chan = devm_kcalloc(indio_dev->dev.parent, indio_dev->num_channels,
> +			    sizeof(*chan), GFP_KERNEL);
> +	if (!chan)
> +		return -ENOMEM;
> +
> +	indio_dev->channels = chan;
> +
> +	for (i = 0; i < indio_dev->num_channels; i++) {
> +		*chan = channels[i];
> +		chan->info_mask_shared_by_all |=
> +			BIT(IIO_CHAN_INFO_LOW_PASS_FILTER_3DB_FREQUENCY);
Why is this not just set in the originally channel array?
> +		if (chan->type != IIO_TEMP) {
> +			chan->info_mask_shared_by_type_available |=
> +				BIT(IIO_CHAN_INFO_SCALE);
> +			chan->ext_info = ad7192_calibsys_ext_info;
Same for these, why not just put them in the original channel array so
they become constant data that we just copy in here.

This whole section then just becomes a memcpy.
I'm not yet clear why we can't just pick from static const arrays
in the first place and need to make this copy.

> +		}
> +		chan++;
> +	}
> +
> +	return 0;
> +}
> +
> +static int ad7192_probe(struct spi_device *spi)
> +{
> +	struct ad7192_state *st;
> +	struct iio_dev *indio_dev;
> +	int ret, voltage_uv = 0;
> +
> +	if (!spi->irq) {
> +		dev_err(&spi->dev, "no IRQ?\n");
> +		return -ENODEV;
> +	}
> +
> +	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	st = iio_priv(indio_dev);
> +
> +	mutex_init(&st->lock);
> +
> +	st->avdd = devm_regulator_get(&spi->dev, "avdd");
> +	if (IS_ERR(st->avdd))
> +		return PTR_ERR(st->avdd);
> +
> +	ret = regulator_enable(st->avdd);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to enable specified AVdd supply\n");
> +		return ret;
> +	}
> +
> +	st->dvdd = devm_regulator_get(&spi->dev, "dvdd");
> +	if (IS_ERR(st->dvdd)) {
> +		ret = PTR_ERR(st->dvdd);
> +		goto error_disable_avdd;
> +	}
> +
> +	ret = regulator_enable(st->dvdd);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to enable specified DVdd supply\n");
> +		goto error_disable_avdd;
> +	}
> +
> +	voltage_uv = regulator_get_voltage(st->avdd);
> +
> +	if (voltage_uv)
> +		st->int_vref_mv = voltage_uv / 1000;
> +	else
> +		dev_err(&spi->dev, "Device tree error, reference voltage undefined\n");

I'd make this a hard requirement.  The driver should fail to probe if this
isn't defined.  Alternative is to put a 'guess' in there based
on whatever the datasheet suggests is a nominal value for it.

> +
> +	spi_set_drvdata(spi, indio_dev);
> +	st->devid = spi_get_device_id(spi)->driver_data;
> +	indio_dev->dev.parent = &spi->dev;
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	ret = ad7192_channels_config(indio_dev);
> +	if (ret < 0)
> +		goto error_disable_dvdd;
> +
> +	if (st->devid == ID_AD7195)
> +		indio_dev->info = &ad7195_info;
> +	else
> +		indio_dev->info = &ad7192_info;
> +
> +	ad_sd_init(&st->sd, indio_dev, spi, &ad7192_sigma_delta_info);
> +
> +	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
> +	if (ret)
> +		goto error_disable_dvdd;
> +
> +	st->fclk = AD7192_INT_FREQ_MHZ;
> +
> +	st->mclk = devm_clk_get(&st->sd.spi->dev, "mclk");
> +	if (IS_ERR(st->mclk) && PTR_ERR(st->mclk) != -ENOENT) {
> +		ret = PTR_ERR(st->mclk);
> +		goto error_remove_trigger;
> +	}
> +
> +	st->clock_sel = ad7192_of_clock_select(st);
> +
> +	if (st->clock_sel == AD7192_CLK_EXT_MCLK1_2 ||
> +	    st->clock_sel == AD7192_CLK_EXT_MCLK2) {
> +		ret = clk_prepare_enable(st->mclk);
> +		if (ret < 0)
> +			goto error_remove_trigger;
> +
> +		st->fclk = clk_get_rate(st->mclk);
> +		if (!ad7192_valid_external_frequency(st->fclk)) {
> +			ret = -EINVAL;
> +			dev_err(&spi->dev,
> +				"External clock frequency out of bounds\n");
> +			goto error_disable_clk;
> +		}
> +	}
> +
> +	ret = ad7192_setup(st, spi->dev.of_node);
> +	if (ret)
> +		goto error_disable_clk;
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret < 0)
> +		goto error_disable_clk;
nitpick : blank line here would ever so slightly improve readability.

> +	return 0;
> +
> +error_disable_clk:
> +	clk_disable_unprepare(st->mclk);
> +error_remove_trigger:
> +	ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +error_disable_dvdd:
> +	regulator_disable(st->dvdd);
> +error_disable_avdd:
> +	regulator_disable(st->avdd);
> +
> +	return ret;
> +}
> +
> +static int ad7192_remove(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct ad7192_state *st = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	clk_disable_unprepare(st->mclk);
> +	ad_sd_cleanup_buffer_and_trigger(indio_dev);
> +
> +	regulator_disable(st->dvdd);
> +	regulator_disable(st->avdd);
> +
> +	return 0;
> +}
> +
> +static const struct spi_device_id ad7192_id[] = {
> +	{"ad7190", ID_AD7190},
> +	{"ad7192", ID_AD7192},
> +	{"ad7193", ID_AD7193},
> +	{"ad7195", ID_AD7195},

Given the driver needs some dt properties to successfully
probe there is little point in maintaining the pre DT means
of probing it.  If you move the ID_* over to the of_id table
you can get rid of this entirely I think.

> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(spi, ad7192_id);
> +
> +static const struct of_device_id ad7192_of_match[] = {
> +	{ .compatible = "adi,ad7190" },
> +	{ .compatible = "adi,ad7192" },
> +	{ .compatible = "adi,ad7193" },
> +	{ .compatible = "adi,ad7195" },
> +	{}
> +};
> +
> +MODULE_DEVICE_TABLE(of, ad7192_of_match);
> +
> +static struct spi_driver ad7192_driver = {
> +	.driver = {
> +		.name	= "ad7192",
> +		.of_match_table = ad7192_of_match,
> +	},
> +	.probe		= ad7192_probe,
> +	.remove		= ad7192_remove,
> +	.id_table	= ad7192_id,
> +};
> +module_spi_driver(ad7192_driver);
> +
> +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@xxxxxxxxxx>");
> +MODULE_DESCRIPTION("Analog Devices AD7190, AD7192, AD7193, AD7195 ADC");
> +MODULE_LICENSE("GPL v2");

...



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