On Thu, 18 Oct 2018 14:04:53 +0300 Stefan Popa <stefan.popa@xxxxxxxxxx> wrote: > The ad7124-4 and ad7124-8 are a family of 4 and 8 channel sigma-delta ADCs > with 24-bit precision and reference. > > Three power modes are available which in turn affect the output data rate: > * Full power: 9.38 SPS to 19,200 SPS > * Mid power: 2.34 SPS to 4800 SPS > * Low power: 1.17 SPS to 2400 SPS > > The ad7124-4 can be configured to have four differential inputs, while > ad7124-8 can have 8. Moreover, ad7124 also supports per channel > configuration. Each configuration consists of gain, reference source, > output data rate and bipolar/unipolar configuration. > > Datasheets: > Link: http://www.analog.com/media/en/technical-documentation/data-sheets/AD7124-4.pdf > Link: http://www.analog.com/media/en/technical-documentation/data-sheets/ad7124-8.pdf > > Signed-off-by: Stefan Popa <stefan.popa@xxxxxxxxxx> Hi Stefan, Just a couple of small things from me. See inline. Thanks, Jonathan > --- > MAINTAINERS | 7 + > drivers/iio/adc/Kconfig | 11 + > drivers/iio/adc/Makefile | 1 + > drivers/iio/adc/ad7124.c | 655 +++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 674 insertions(+) > create mode 100644 drivers/iio/adc/ad7124.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index f642044..3a1bfcb 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -839,6 +839,13 @@ S: Supported > F: drivers/iio/dac/ad5758.c > F: Documentation/devicetree/bindings/iio/dac/ad5758.txt > > +ANALOG DEVICES INC AD7124 DRIVER > +M: Stefan Popa <stefan.popa@xxxxxxxxxx> > +L: linux-iio@xxxxxxxxxxxxxxx > +W: http://ez.analog.com/community/linux-device-drivers > +S: Supported > +F: drivers/iio/adc/ad7124.c > + > ANALOG DEVICES INC AD9389B DRIVER > M: Hans Verkuil <hans.verkuil@xxxxxxxxx> > L: linux-media@xxxxxxxxxxxxxxx > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig > index a52fea8..148a10f 100644 > --- a/drivers/iio/adc/Kconfig > +++ b/drivers/iio/adc/Kconfig > @@ -10,6 +10,17 @@ config AD_SIGMA_DELTA > select IIO_BUFFER > select IIO_TRIGGERED_BUFFER > > +config AD7124 > + tristate "Analog Devices AD7124 and similar sigma-delta ADCs driver" > + depends on SPI_MASTER > + select AD_SIGMA_DELTA > + help > + Say yes here to build support for Analog Devices AD7124-4 and AD7124-8 > + SPI analog to digital converters (ADC). > + > + To compile this driver as a module, choose M here: the module will be > + called ad7124. > + > 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 a6e6a0b..76168b2 100644 > --- a/drivers/iio/adc/Makefile > +++ b/drivers/iio/adc/Makefile > @@ -5,6 +5,7 @@ > > # When adding new entries keep the list in alphabetical order > obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o > +obj-$(CONFIG_AD7124) += ad7124.o > obj-$(CONFIG_AD7266) += ad7266.o > obj-$(CONFIG_AD7291) += ad7291.o > obj-$(CONFIG_AD7298) += ad7298.o > diff --git a/drivers/iio/adc/ad7124.c b/drivers/iio/adc/ad7124.c > new file mode 100644 > index 0000000..c6d9798 > --- /dev/null > +++ b/drivers/iio/adc/ad7124.c > @@ -0,0 +1,655 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +/* > + * AD7124 SPI ADC driver > + * > + * Copyright 2018 Analog Devices Inc. > + */ > +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/device.h> > +#include <linux/err.h> > +#include <linux/kernel.h> > +#include <linux/module.h> > +#include <linux/regulator/consumer.h> > +#include <linux/spi/spi.h> > + > +#include <linux/iio/iio.h> > +#include <linux/iio/adc/ad_sigma_delta.h> > +#include <linux/iio/sysfs.h> > + > +/* AD7124 registers */ > +#define AD7124_COMMS 0x00 > +#define AD7124_STATUS 0x00 > +#define AD7124_ADC_CONTROL 0x01 > +#define AD7124_DATA 0x02 > +#define AD7124_IO_CONTROL_1 0x03 > +#define AD7124_IO_CONTROL_2 0x04 > +#define AD7124_ID 0x05 > +#define AD7124_ERROR 0x06 > +#define AD7124_ERROR_EN 0x07 > +#define AD7124_MCLK_COUNT 0x08 > +#define AD7124_CHANNEL(x) (0x09 + (x)) > +#define AD7124_CONFIG(x) (0x19 + (x)) > +#define AD7124_FILTER(x) (0x21 + (x)) > +#define AD7124_OFFSET(x) (0x29 + (x)) > +#define AD7124_GAIN(x) (0x31 + (x)) > + > +/* AD7124_STATUS */ > +#define AD7124_STATUS_POR_FLAG_MSK BIT(4) > + > +/* AD7124_ADC_CONTROL */ > +#define AD7124_ADC_CTRL_PWR_MSK GENMASK(7, 6) > +#define AD7124_ADC_CTRL_PWR(x) FIELD_PREP(AD7124_ADC_CTRL_PWR_MSK, x) > +#define AD7124_ADC_CTRL_MODE_MSK GENMASK(5, 2) > +#define AD7124_ADC_CTRL_MODE(x) FIELD_PREP(AD7124_ADC_CTRL_MODE_MSK, x) > + > +/* AD7124_CHANNEL_X */ > +#define AD7124_CHANNEL_EN_MSK BIT(15) > +#define AD7124_CHANNEL_EN(x) FIELD_PREP(AD7124_CHANNEL_EN_MSK, x) > +#define AD7124_CHANNEL_SETUP_MSK GENMASK(14, 12) > +#define AD7124_CHANNEL_SETUP(x) FIELD_PREP(AD7124_CHANNEL_SETUP_MSK, x) > +#define AD7124_CHANNEL_AINP_MSK GENMASK(9, 5) > +#define AD7124_CHANNEL_AINP(x) FIELD_PREP(AD7124_CHANNEL_AINP_MSK, x) > +#define AD7124_CHANNEL_AINM_MSK GENMASK(4, 0) > +#define AD7124_CHANNEL_AINM(x) FIELD_PREP(AD7124_CHANNEL_AINM_MSK, x) > + > +/* AD7124_CONFIG_X */ > +#define AD7124_CONFIG_BIPOLAR_MSK BIT(11) > +#define AD7124_CONFIG_BIPOLAR(x) FIELD_PREP(AD7124_CONFIG_BIPOLAR_MSK, x) > +#define AD7124_CONFIG_REF_SEL_MSK GENMASK(4, 3) > +#define AD7124_CONFIG_REF_SEL(x) FIELD_PREP(AD7124_CONFIG_REF_SEL_MSK, x) > +#define AD7124_CONFIG_PGA_MSK GENMASK(2, 0) > +#define AD7124_CONFIG_PGA(x) FIELD_PREP(AD7124_CONFIG_PGA_MSK, x) > + > +/* AD7124_FILTER_X */ > +#define AD7124_FILTER_FS_MSK GENMASK(10, 0) > +#define AD7124_FILTER_FS(x) FIELD_PREP(AD7124_FILTER_FS_MSK, x) > + > +enum ad7124_ids { > + ID_AD7124_4, > + ID_AD7124_8, > +}; > + > +enum ad7124_ref_sel { > + AD7124_REFIN1, > + AD7124_REFIN2, > + AD7124_INT_REF, > + AD7124_AVDD_REF, > +}; > + > +enum ad7124_power_mode { > + AD7124_LOW_POWER, > + AD7124_MID_POWER, > + AD7124_FULL_POWER, > +}; > + > +static const unsigned int ad7124_gain[8] = { > + 1, 2, 4, 8, 16, 32, 64, 128 > +}; > + > +static const int ad7124_master_clk_freq_hz[3] = { > + [AD7124_LOW_POWER] = 76800, > + [AD7124_MID_POWER] = 153600, > + [AD7124_FULL_POWER] = 614400, > +}; > + > +static const char * const ad7124_ref_names[] = { > + [AD7124_REFIN1] = "refin1", > + [AD7124_REFIN2] = "refin2", > + [AD7124_INT_REF] = "int", > + [AD7124_AVDD_REF] = "avdd", > +}; > + > +struct ad7124_chip_info { > + unsigned int num_inputs; > +}; > + > +struct ad7124_channel_config { > + enum ad7124_ref_sel refsel; > + bool bipolar; > + unsigned int ain; > + unsigned int vref_mv; > + unsigned int pga_bits; > + unsigned int odr; > +}; > + > +struct ad7124_state { > + const struct ad7124_chip_info *chip_info; > + struct ad_sigma_delta sd; > + struct ad7124_channel_config channel_config[4]; > + struct regulator *vref[4]; > + struct clk *mclk; > + unsigned int adc_control; > + unsigned int num_channels; > +}; > + > +static const struct iio_chan_spec ad7124_channel_template = { > + .type = IIO_VOLTAGE, > + .indexed = 1, > + .differential = 1, > + .channel = 0, > + .address = 0, > + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | > + BIT(IIO_CHAN_INFO_SCALE) | > + BIT(IIO_CHAN_INFO_OFFSET) | > + BIT(IIO_CHAN_INFO_SAMP_FREQ), > + .scan_index = 0, Given I would imagine this is always overwritten, probably no point in setting it here. Same with channel and address above. > + .scan_type = { > + .sign = 'u', > + .realbits = 24, > + .storagebits = 32, > + .shift = 0, A shift of 0 is a fairly obvious default and the c standard guarantees the variable will be initialized. Hence no need to set it here. > + }, > +}; > + > +static struct ad7124_chip_info ad7124_chip_info_tbl[] = { > + [ID_AD7124_4] = { > + .num_inputs = 8, > + }, > + [ID_AD7124_8] = { > + .num_inputs = 16, > + }, > +}; > + > +static int ad7124_find_closest_match(const int *array, > + unsigned int size, int val) > +{ > + int i; > + > + for (i = 0; i < size; i++) { > + if (val <= array[i]) > + return i; > + } > + > + return size - 1; > +} > + > +static int ad7124_spi_write_mask(struct ad7124_state *st, > + unsigned int addr, > + unsigned long mask, > + unsigned int val, > + unsigned int bytes) > +{ > + unsigned int readval; > + int ret; > + > + ret = ad_sd_read_reg(&st->sd, addr, bytes, &readval); > + if (ret < 0) > + return ret; > + > + readval &= ~mask; > + readval |= val; > + > + return ad_sd_write_reg(&st->sd, addr, bytes, readval); > +} > + > +static int ad7124_set_mode(struct ad_sigma_delta *sd, > + enum ad_sigma_delta_mode mode) > +{ > + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); > + > + st->adc_control &= ~AD7124_ADC_CTRL_MODE_MSK; > + st->adc_control |= AD7124_ADC_CTRL_MODE(mode); > + > + return ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); > +} > + > +static int ad7124_set_channel(struct ad_sigma_delta *sd, unsigned int channel) > +{ > + struct ad7124_state *st = container_of(sd, struct ad7124_state, sd); > + unsigned int val; > + > + val = st->channel_config[channel].ain | AD7124_CHANNEL_EN(1) | > + AD7124_CHANNEL_SETUP(channel); > + > + return ad_sd_write_reg(&st->sd, AD7124_CHANNEL(channel), 2, val); > +} > + > +static const struct ad_sigma_delta_info ad7124_sigma_delta_info = { > + .set_channel = ad7124_set_channel, > + .set_mode = ad7124_set_mode, > + .has_registers = true, > + .addr_shift = 0, > + .read_mask = BIT(6), > + .data_reg = AD7124_DATA, > +}; > + > +static int ad7124_set_channel_odr(struct ad7124_state *st, > + unsigned int channel, > + unsigned int odr) > +{ > + unsigned int fclk, odr_sel_bits; > + int ret; > + > + fclk = clk_get_rate(st->mclk); > + /* > + * FS[10:0] = fCLK / (fADC x 32) where: > + * fADC is the output data rate > + * fCLK is the master clock frequency > + * FS[10:0] are the bits in the filter register > + * FS[10:0] can have a value from 1 to 2047 > + */ > + odr_sel_bits = DIV_ROUND_CLOSEST(fclk, odr * 32); > + if (odr_sel_bits < 1) > + odr_sel_bits = 1; > + else if (odr_sel_bits > 2047) > + odr_sel_bits = 2047; > + > + ret = ad7124_spi_write_mask(st, AD7124_FILTER(channel), > + AD7124_FILTER_FS_MSK, > + AD7124_FILTER_FS(odr_sel_bits), 3); > + if (ret < 0) > + return ret; > + /* fADC = fCLK / (FS[10:0] x 32) */ > + st->channel_config[channel].odr = > + DIV_ROUND_CLOSEST(fclk, odr_sel_bits * 32); > + > + return 0; > +} > + > +static int ad7124_read_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int *val, int *val2, long info) > +{ > + struct ad7124_state *st = iio_priv(indio_dev); > + int idx, ret; > + > + switch (info) { > + case IIO_CHAN_INFO_RAW: > + ret = ad_sigma_delta_single_conversion(indio_dev, chan, val); > + if (ret < 0) > + return ret; > + > + /* After the conversion is performed, disable the channel */ > + ret = ad_sd_write_reg(&st->sd, > + AD7124_CHANNEL(chan->address), 2, > + st->channel_config[chan->address].ain | > + AD7124_CHANNEL_EN(0)); > + if (ret < 0) > + return ret; > + > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SCALE: > + idx = st->channel_config[chan->address].pga_bits; > + *val = st->channel_config[chan->address].vref_mv / > + ad7124_gain[idx]; > + if (st->channel_config[chan->address].bipolar) > + *val2 = chan->scan_type.realbits - 1; > + else > + *val2 = chan->scan_type.realbits; > + > + return IIO_VAL_FRACTIONAL_LOG2; > + case IIO_CHAN_INFO_OFFSET: > + if (st->channel_config[chan->address].bipolar) { > + /* Code = 2^(n − 1) × ((Ain × Gain / Vref) + 1) */ > + idx = st->channel_config[chan->address].pga_bits; > + *val = -(st->channel_config[chan->address].vref_mv / > + ad7124_gain[idx]); > + } else { > + *val = 0; > + } > + > + return IIO_VAL_INT; > + case IIO_CHAN_INFO_SAMP_FREQ: > + *val = st->channel_config[chan->address].odr; > + > + return IIO_VAL_INT; > + default: > + return -EINVAL; > + } > +} > + > +static int ad7124_write_raw(struct iio_dev *indio_dev, > + struct iio_chan_spec const *chan, > + int val, int val2, long info) > +{ > + struct ad7124_state *st = iio_priv(indio_dev); > + > + switch (info) { > + case IIO_CHAN_INFO_SAMP_FREQ: > + return ad7124_set_channel_odr(st, chan->address, val); We should probably have a sanity check for val2 being zero given we are just ignoring it... > + default: > + return -EINVAL; > + } > +} > + > +static const struct iio_info ad7124_info = { > + .read_raw = ad7124_read_raw, > + .write_raw = ad7124_write_raw, > +}; > + > +static int ad7124_soft_reset(struct ad7124_state *st) > +{ > + unsigned int readval, timeout; > + int ret; > + > + ret = ad_sd_reset(&st->sd, 64); > + if (ret < 0) > + return ret; > + > + timeout = 100; > + do { > + ret = ad_sd_read_reg(&st->sd, AD7124_STATUS, 1, &readval); > + if (ret < 0) > + return ret; > + > + if (!(readval & AD7124_STATUS_POR_FLAG_MSK)) > + return 0; > + > + /* The AD7124 requires typically 2ms to power up and settle */ > + usleep_range(100, 2000); > + } while (--timeout); > + > + dev_err(&st->sd.spi->dev, "Soft reset failed\n"); > + > + return -EIO; > +} > + > +static int ad7124_init_channel_vref(struct ad7124_state *st, > + unsigned int channel_number) > +{ > + unsigned int refsel = st->channel_config[channel_number].refsel; > + > + switch (refsel) { > + case AD7124_REFIN1: > + case AD7124_REFIN2: > + case AD7124_AVDD_REF: > + if (IS_ERR(st->vref[refsel])) { > + dev_err(&st->sd.spi->dev, > + "Error, trying to use external voltage reference without a %s regulator.", > + ad7124_ref_names[refsel]); > + return PTR_ERR(st->vref[refsel]); > + } > + st->channel_config[channel_number].vref_mv = > + regulator_get_voltage(st->vref[refsel]); > + /* Conversion from uV to mV */ > + st->channel_config[channel_number].vref_mv /= 1000; > + break; > + case AD7124_INT_REF: > + st->channel_config[channel_number].vref_mv = 2500; > + break; > + default: > + dev_err(&st->sd.spi->dev, "Invalid reference %d\n", refsel); > + return -EINVAL; > + } > + > + return 0; > +} > + > +static int ad7124_of_parse_channel_config(struct iio_dev *indio_dev, > + struct device_node *np) > +{ > + struct ad7124_state *st = iio_priv(indio_dev); > + struct device_node *chan_node, *child; > + struct iio_chan_spec *chan; > + unsigned int ain[2], channel = 0, tmp; > + int ret, res; > + > + chan_node = of_get_child_by_name(np, "adi,channels"); > + if (!chan_node) { > + dev_err(indio_dev->dev.parent, > + "failed to find channels node\n"); > + return -ENODEV; > + } > + > + st->num_channels = of_get_available_child_count(chan_node); > + if (!st->num_channels) { > + dev_err(indio_dev->dev.parent, "no channel children\n"); > + return -ENODEV; > + } > + > + chan = devm_kcalloc(indio_dev->dev.parent, st->num_channels, > + sizeof(*chan), GFP_KERNEL); > + if (!chan) > + return -ENOMEM; > + > + indio_dev->channels = chan; > + indio_dev->num_channels = st->num_channels; > + > + for_each_available_child_of_node(chan_node, child) { > + ret = of_property_read_u32_array(child, "reg", ain, 2); > + if (ret) > + goto err; > + > + ret = of_property_read_u32(child, > + "adi,channel-number", &channel); The line break here is a little odd. I think the string should be on the line above probably (nitpick of the day ;) > + if (ret) > + goto err; > + > + if (ain[0] >= st->chip_info->num_inputs || > + ain[1] >= st->chip_info->num_inputs) { > + dev_err(indio_dev->dev.parent, > + "Input pin number out of range.\n"); > + ret = -EINVAL; > + goto err; > + } > + st->channel_config[channel].ain = AD7124_CHANNEL_AINP(ain[0]) | > + AD7124_CHANNEL_AINM(ain[1]); > + st->channel_config[channel].bipolar = > + of_property_read_bool(child, "adi,bipolar"); > + > + ret = of_property_read_u32(child, "adi,reference-select", &tmp); > + if (ret) > + st->channel_config[channel].refsel = AD7124_INT_REF; > + else > + st->channel_config[channel].refsel = tmp; > + > + ret = of_property_read_u32(child, "adi,gain", &tmp); > + if (ret) { > + st->channel_config[channel].pga_bits = 0; > + } else { > + res = ad7124_find_closest_match(ad7124_gain, > + ARRAY_SIZE(ad7124_gain), tmp); > + st->channel_config[channel].pga_bits = res; > + } > + > + ret = of_property_read_u32(child, "adi,odr-hz", &tmp); > + if (ret) > + /* > + * 9 SPS is the minimum output data rate supported > + * regardless of the selected power mode. > + */ > + st->channel_config[channel].odr = 9; > + else > + st->channel_config[channel].odr = tmp; > + > + *chan = ad7124_channel_template; > + chan->address = channel; > + chan->scan_index = channel; > + chan->channel = ain[0]; > + chan->channel2 = ain[1]; > + > + chan++; > + } > + of_node_put(chan_node); > + > + return 0; > +err: > + of_node_put(chan_node); > + of_node_put(child); > + > + return ret; > +} > + > +static int ad7124_setup(struct ad7124_state *st) > +{ > + unsigned int val, fclk, power_mode; > + int i, ret; > + > + fclk = clk_get_rate(st->mclk); > + if (!fclk) > + return -EINVAL; > + > + /* The power mode changes the master clock frequency */ > + power_mode = ad7124_find_closest_match(ad7124_master_clk_freq_hz, > + ARRAY_SIZE(ad7124_master_clk_freq_hz), > + fclk); > + if (fclk != ad7124_master_clk_freq_hz[power_mode]) { > + ret = clk_set_rate(st->mclk, fclk); > + if (ret) > + return ret; > + } > + > + /* Set the power mode */ > + st->adc_control &= ~AD7124_ADC_CTRL_PWR_MSK; > + st->adc_control |= AD7124_ADC_CTRL_PWR(power_mode); > + ret = ad_sd_write_reg(&st->sd, AD7124_ADC_CONTROL, 2, st->adc_control); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < st->num_channels; i++) { > + val = st->channel_config[i].ain | AD7124_CHANNEL_SETUP(i); > + ret = ad_sd_write_reg(&st->sd, AD7124_CHANNEL(i), 2, val); > + if (ret < 0) > + return ret; > + > + ret = ad7124_init_channel_vref(st, i); > + if (ret < 0) > + return ret; > + > + val = AD7124_CONFIG_BIPOLAR(st->channel_config[i].bipolar) | > + AD7124_CONFIG_REF_SEL(st->channel_config[i].refsel) | > + AD7124_CONFIG_PGA(st->channel_config[i].pga_bits); > + ret = ad_sd_write_reg(&st->sd, AD7124_CONFIG(i), 2, val); > + if (ret < 0) > + return ret; > + > + ret = ad7124_set_channel_odr(st, i, st->channel_config[i].odr); > + if (ret < 0) > + return ret; > + } > + > + return ret; > +} > + > +static int ad7124_probe(struct spi_device *spi) > +{ > + const struct spi_device_id *id; > + struct ad7124_state *st; > + struct iio_dev *indio_dev; > + int i, ret; > + > + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); > + if (!indio_dev) > + return -ENOMEM; > + > + st = iio_priv(indio_dev); > + > + id = spi_get_device_id(spi); > + st->chip_info = &ad7124_chip_info_tbl[id->driver_data]; > + > + ad_sd_init(&st->sd, indio_dev, spi, &ad7124_sigma_delta_info); > + > + spi_set_drvdata(spi, indio_dev); > + > + indio_dev->dev.parent = &spi->dev; > + indio_dev->name = spi_get_device_id(spi)->name; > + indio_dev->modes = INDIO_DIRECT_MODE; > + indio_dev->info = &ad7124_info; > + > + ret = ad7124_of_parse_channel_config(indio_dev, spi->dev.of_node); > + if (ret < 0) > + return ret; > + > + for (i = 0; i < ARRAY_SIZE(st->vref); i++) { > + if (i != AD7124_INT_REF) > + st->vref[i] = devm_regulator_get_optional(&spi->dev, > + ad7124_ref_names[i]); The complexity of regulator_get_optional, is which cases actually mean there hasn't been a regulator specified (which is fine) rather than it's not ready or there has been an error getting the one that was specified. So I 'believe' that you should only be continuing if you get -ENODEV. Anything else and you should give up on the probe (perhaps to come back later if it's a defer. > + if (IS_ERR_OR_NULL(st->vref[i])) > + continue; > + > + ret = regulator_enable(st->vref[i]); > + if (ret) > + return ret; > + } > + > + st->mclk = devm_clk_get(&spi->dev, "mclk"); > + if (IS_ERR(st->mclk)) { > + ret = PTR_ERR(st->mclk); > + goto error_regulator_disable; > + } > + > + ret = clk_prepare_enable(st->mclk); > + if (ret < 0) > + goto error_regulator_disable; > + > + ret = ad7124_soft_reset(st); > + if (ret < 0) > + goto error_clk_disable_unprepare; > + > + ret = ad7124_setup(st); > + if (ret < 0) > + goto error_clk_disable_unprepare; > + > + ret = ad_sd_setup_buffer_and_trigger(indio_dev); > + if (ret < 0) > + goto error_clk_disable_unprepare; > + > + ret = iio_device_register(indio_dev); > + if (ret < 0) { > + dev_err(&spi->dev, "Failed to register iio device\n"); > + goto error_remove_trigger; > + } > + > + return 0; > + > +error_remove_trigger: > + ad_sd_cleanup_buffer_and_trigger(indio_dev); > +error_clk_disable_unprepare: > + clk_disable_unprepare(st->mclk); > +error_regulator_disable: > + for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) { > + if (!IS_ERR_OR_NULL(st->vref[i])) > + regulator_disable(st->vref[i]); > + } > + > + return ret; > +} > + > +static int ad7124_remove(struct spi_device *spi) > +{ > + struct iio_dev *indio_dev = spi_get_drvdata(spi); > + struct ad7124_state *st = iio_priv(indio_dev); > + int i; > + > + iio_device_unregister(indio_dev); > + ad_sd_cleanup_buffer_and_trigger(indio_dev); > + clk_disable_unprepare(st->mclk); I know it is probably fine, but I would definitely prefer the ordering in here and the error paths in probe to be the same (and the reverse of the probe order). That puts clk_disable_unprepare before ad_sd_cleanup_buffer_and_trigger. > + > + for (i = ARRAY_SIZE(st->vref) - 1; i >= 0; i--) { > + if (!IS_ERR_OR_NULL(st->vref[i])) > + regulator_disable(st->vref[i]); > + } > + > + return 0; > +} > + > +static const struct spi_device_id ad7124_id_table[] = { > + { "ad7124-4", ID_AD7124_4 }, > + { "ad7124-8", ID_AD7124_8 }, > + {} > +}; > +MODULE_DEVICE_TABLE(spi, ad7124_id_table); > + > +static const struct of_device_id ad7124_of_match[] = { > + { .compatible = "adi,ad7124-4" }, > + { .compatible = "adi,ad7124-8" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, ad7124_of_match); > + > +static struct spi_driver ad71124_driver = { > + .driver = { > + .name = "ad7124", > + .of_match_table = ad7124_of_match, > + }, > + .probe = ad7124_probe, > + .remove = ad7124_remove, > + .id_table = ad7124_id_table, > +}; > +module_spi_driver(ad71124_driver); > + > +MODULE_AUTHOR("Stefan Popa <stefan.popa@xxxxxxxxxx>"); > +MODULE_DESCRIPTION("Analog Devices AD7124 SPI driver"); > +MODULE_LICENSE("GPL");