[PATCH v1 2/2] iio: adc: add Nuvoton NCT720x ADC driver
Yu-Hsian Yang
j2anfernee at gmail.com
Thu Nov 7 18:17:54 AEDT 2024
Dear anish kumar,
Thank you for your response.
anish kumar <yesanishhere at gmail.com> 於 2024年11月7日 週四 下午2:14寫道：
>
> On Tue, Nov 5, 2024 at 6:39 PM Eason Yang <j2anfernee at gmail.com> wrote:
> >
> > Add Nuvoton NCT7201/NCT7202 system voltage monitor 12-bit ADC driver
> >
> > NCT7201/NCT7202 supports up to 12 analog voltage monitor inputs and up to
> > 4 SMBus addresses by ADDR pin. Meanwhile, ALERT# hardware event pins for
> > independent alarm signals, and the all threshold values could be set for
> > system protection without any timing delay. It also supports reset input
> > RSTIN# to recover system from a fault condition.
> >
> > Currently, only single-edge mode conversion and threshold events support.
> >
> > Signed-off-by: Eason Yang <j2anfernee at gmail.com>
> > ---
> > MAINTAINERS | 1 +
> > drivers/iio/adc/Kconfig | 9 +
> > drivers/iio/adc/Makefile | 1 +
> > drivers/iio/adc/nct720x.c | 617 ++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 628 insertions(+)
> > create mode 100644 drivers/iio/adc/nct720x.c
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 68570c58e7aa..9940de0ddca2 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -2753,6 +2753,7 @@ F: arch/arm/mach-npcm/
> > F: arch/arm64/boot/dts/nuvoton/
> > F: drivers/*/*/*npcm*
> > F: drivers/*/*npcm*
> > +F: drivers/iio/adc/nct720x.c
> > F: drivers/rtc/rtc-nct3018y.c
> > F: include/dt-bindings/clock/nuvoton,npcm7xx-clock.h
> > F: include/dt-bindings/clock/nuvoton,npcm845-clk.h
> > diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> > index 6c4e74420fd2..adbbf0ca6f57 100644
> > --- a/drivers/iio/adc/Kconfig
> > +++ b/drivers/iio/adc/Kconfig
> > @@ -1008,6 +1008,15 @@ config NAU7802
> > To compile this driver as a module, choose M here: the
> > module will be called nau7802.
> >
> > +config NCT720X
> > + tristate "Nuvoton Instruments NCT7201 and NCT7202 Power Monitor"
> > + depends on I2C
> > + help
> > + If you say yes here you get support for the Nuvoton NCT7201 and
> > + NCT7202 Voltage Monitor.
> > + This driver can also be built as a module. If so, the module
> > + will be called nct720x.
> > +
> > config NPCM_ADC
> > tristate "Nuvoton NPCM ADC driver"
> > depends on ARCH_NPCM || COMPILE_TEST
> > diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> > index 7b91cd98c0e0..f53318e5aa04 100644
> > --- a/drivers/iio/adc/Makefile
> > +++ b/drivers/iio/adc/Makefile
> > @@ -91,6 +91,7 @@ obj-$(CONFIG_MESON_SARADC) += meson_saradc.o
> > obj-$(CONFIG_MP2629_ADC) += mp2629_adc.o
> > obj-$(CONFIG_MXS_LRADC_ADC) += mxs-lradc-adc.o
> > obj-$(CONFIG_NAU7802) += nau7802.o
> > +obj-$(CONFIG_NCT720X) += nct720x.o
> > obj-$(CONFIG_NPCM_ADC) += npcm_adc.o
> > obj-$(CONFIG_PAC1921) += pac1921.o
> > obj-$(CONFIG_PAC1934) += pac1934.o
> > diff --git a/drivers/iio/adc/nct720x.c b/drivers/iio/adc/nct720x.c
> > new file mode 100644
> > index 000000000000..e589479fd06e
> > --- /dev/null
> > +++ b/drivers/iio/adc/nct720x.c
> > @@ -0,0 +1,617 @@
> > +// SPDX-License-Identifier: GPL-2.0+
> > +/*
> > + * Driver for Nuvoton nct7201 and nct7202 power monitor chips.
> > + *
> > + * Copyright (c) 2022 Nuvoton Inc.
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/i2c.h>
> > +#include <linux/iio/events.h>
> > +#include <linux/iio/iio.h>
> > +#include <linux/iio/sysfs.h>
> > +#include <linux/init.h>
> > +#include <linux/module.h>
> > +#include <linux/mutex.h>
> > +
> > +#define REG_CHIP_ID 0xFD
> > +#define NCT720X_ID 0xD7
> > +#define REG_VENDOR_ID 0xFE
> > +#define NUVOTON_ID 0x50
> > +#define REG_DEVICE_ID 0xFF
> > +#define NCT720X_DEVICE_ID 0x12
> > +#define VIN_MAX 12 /* Counted from 1 */
> > +#define NCT7201_VIN_MAX 8
> > +#define NCT7202_VIN_MAX 12
> > +#define NCT720X_IN_SCALING 4995
> > +
> > +#define REG_INTERRUPT_STATUS_1 0x0C
> > +#define REG_INTERRUPT_STATUS_2 0x0D
> > +#define REG_VOLT_LOW_BYTE 0x0F
> > +#define REG_CONFIGURATION 0x10
> > +#define CONFIGURATION_START BIT(0)
> > +#define CONFIGURATION_ALERT_MSK BIT(1)
> > +#define CONFIGURATION_CONV_RATE BIT(2)
> > +#define CONFIGURATION_INIT BIT(7)
> > +
> > +#define REG_ADVANCED_CONFIGURATION 0x11
> > +#define ADVANCED_CONF_MOD_ALERT BIT(0)
> > +#define ADVANCED_CONF_MOD_STS BIT(1)
> > +#define ADVANCED_CONF_FAULT_QUEUE BIT(2)
> > +#define ADVANCED_CONF_EN_DEEP_SHUTDOWN BIT(4)
> > +#define ADVANCED_CONF_EN_SMB_TIMEOUT BIT(5)
> > +#define ADVANCED_CONF_MOD_RSTIN BIT(7)
> > +
> > +#define REG_CHANNEL_INPUT_MODE 0x12
> > +#define REG_CHANNEL_ENABLE_1 0x13
> > +#define REG_CHANNEL_ENABLE_2 0x14
> > +#define REG_INTERRUPT_MASK_1 0x15
> > +#define REG_INTERRUPT_MASK_2 0x16
> > +#define REG_BUSY_STATUS 0x1E
> > +#define REG_ONE_SHOT 0x1F
> > +#define REG_SMUS_ADDRESS 0xFC
> > +
> > +static const u8 REG_VIN[VIN_MAX] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05,
> > + 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B};
> > +static const u8 REG_VIN_HIGH_LIMIT[VIN_MAX] = { 0x20, 0x22, 0x24, 0x26, 0x28, 0x2A,
> > + 0x2C, 0x2E, 0x30, 0x32, 0x34, 0x36};
> > +static const u8 REG_VIN_LOW_LIMIT[VIN_MAX] = { 0x21, 0x23, 0x25, 0x27, 0x29, 0x2B,
> > + 0x2D, 0x2F, 0x31, 0x33, 0x35, 0x37};
> > +static const u8 REG_VIN_HIGH_LIMIT_LSB[VIN_MAX] = { 0x40, 0x42, 0x44, 0x46, 0x48, 0x4A,
> > + 0x4C, 0x4E, 0x50, 0x52, 0x54, 0x56};
> > +static const u8 REG_VIN_LOW_LIMIT_LSB[VIN_MAX] = { 0x41, 0x43, 0x45, 0x47, 0x49, 0x4B,
> > + 0x4D, 0x4F, 0x51, 0x53, 0x55, 0x57};
> > +static u8 nct720x_chan_to_index[] = {
> > + 0, /* Not used */
> > + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11
> > +};
> > +
> > +
> > +/* List of supported devices */
> > +enum nct720x_chips {
> > + nct7201, nct7202
> > +};
> > +
> > +struct nct720x_chip_info {
> > + struct i2c_client *client;
> > + enum nct720x_chips type;
> > + struct mutex access_lock; /* for multi-byte read and write operations */
> > + int vin_max; /* number of VIN channels */
> > + u32 vin_mask;
> > + bool use_read_byte_vin;
> > +};
> > +
> > +static const struct iio_event_spec nct720x_events[] = {
> > + {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_RISING,
> > + .mask_separate = BIT(IIO_EV_INFO_VALUE) |
> > + BIT(IIO_EV_INFO_ENABLE),
> > + }, {
> > + .type = IIO_EV_TYPE_THRESH,
> > + .dir = IIO_EV_DIR_FALLING,
> > + .mask_separate = BIT(IIO_EV_INFO_VALUE) |
> > + BIT(IIO_EV_INFO_ENABLE),
> > + },
> > +};
> > +
> > +#define NCT720X_VOLTAGE_CHANNEL(chan, addr) \
> > + { \
> > + .type = IIO_VOLTAGE, \
> > + .indexed = 1, \
> > + .channel = chan, \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
> > + .address = addr, \
> > + .event_spec = nct720x_events, \
> > + .num_event_specs = ARRAY_SIZE(nct720x_events), \
> > + }
> > +
> > +#define NCT720X_VOLTAGE_CHANNEL_DIFF(chan1, chan2, addr) \
> > + { \
> > + .type = IIO_VOLTAGE, \
> > + .indexed = 1, \
> > + .channel = (chan1), \
> > + .channel2 = (chan2), \
> > + .differential = 1, \
> > + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), \
> > + .address = addr, \
> > + .event_spec = nct720x_events, \
> > + .num_event_specs = ARRAY_SIZE(nct720x_events), \
> > + }
> > +
> > +static const struct iio_chan_spec nct720x_channels[] = {
> > + NCT720X_VOLTAGE_CHANNEL(1, 1),
> > + NCT720X_VOLTAGE_CHANNEL(2, 2),
> > + NCT720X_VOLTAGE_CHANNEL(3, 3),
> > + NCT720X_VOLTAGE_CHANNEL(4, 4),
> > + NCT720X_VOLTAGE_CHANNEL(5, 5),
> > + NCT720X_VOLTAGE_CHANNEL(6, 6),
> > + NCT720X_VOLTAGE_CHANNEL(7, 7),
> > + NCT720X_VOLTAGE_CHANNEL(8, 8),
> > + NCT720X_VOLTAGE_CHANNEL(9, 9),
> > + NCT720X_VOLTAGE_CHANNEL(10, 10),
> > + NCT720X_VOLTAGE_CHANNEL(11, 11),
> > + NCT720X_VOLTAGE_CHANNEL(12, 12),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(1, 2, 1),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(3, 4, 3),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(5, 6, 5),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(7, 8, 7),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(9, 10, 9),
> > + NCT720X_VOLTAGE_CHANNEL_DIFF(11, 12, 11),
> > +};
> > +
> > +/* Read 1-byte register. Returns unsigned byte data or -ERRNO on error. */
> > +static int nct720x_read_reg(struct nct720x_chip_info *chip, u8 reg)
> > +{
> > + struct i2c_client *client = chip->client;
> > +
> > + return i2c_smbus_read_byte_data(client, reg);
> > +}
> > +
> > +/* Read 1-byte register. Returns unsigned word data or -ERRNO on error. */
> > +static int nct720x_read_word_swapped_reg(struct nct720x_chip_info *chip, u8 reg)
> > +{
> > + struct i2c_client *client = chip->client;
> > +
> > + return i2c_smbus_read_word_swapped(client, reg);
> > +}
> > +
> > +/*
> > + * Read 2-byte register. Returns register in big-endian format or
> > + * -ERRNO on error.
> > + */
> > +static int nct720x_read_reg16(struct nct720x_chip_info *chip, u8 reg)
> > +{
> > + struct i2c_client *client = chip->client;
> > + int ret, low;
> > +
> > + mutex_lock(&chip->access_lock);
> > + ret = i2c_smbus_read_byte_data(client, reg);
> > + if (ret >= 0) {
> > + low = ret;
> > + ret = i2c_smbus_read_byte_data(client, reg + 1);
> > + if (ret >= 0)
> > + ret = low | (ret << 8);
> > + }
> > +
> > + mutex_unlock(&chip->access_lock);
> > + return ret;
> > +}
> > +
> > +/* Write 1-byte register. Returns 0 or -ERRNO on error. */
> > +static int nct720x_write_reg(struct nct720x_chip_info *chip, u8 reg, u8 val)
> > +{
> > + struct i2c_client *client = chip->client;
> > + int err;
> > +
> > + err = i2c_smbus_write_byte_data(client, reg, val);
> > + /* wait for write command to be finished */
> > + mdelay(10);
> > +
> > + return err;
> > +}
> > +
> > +static int nct720x_read_raw(struct iio_dev *indio_dev,
> > + struct iio_chan_spec const *chan,
> > + int *val, int *val2, long mask)
> > +{
> > + int index = nct720x_chan_to_index[chan->address];
> > + int v1, v2, volt, err;
> > + struct nct720x_chip_info *chip = iio_priv(indio_dev);
> > +
> > + if (chan->type != IIO_VOLTAGE)
> > + return -EOPNOTSUPP;
> > +
> > + switch (mask) {
> > + case IIO_CHAN_INFO_PROCESSED:
> > + mutex_lock(&chip->access_lock);
> > + if (chip->use_read_byte_vin) {
> > + /*
> > + * MNTVIN Low Byte together with MNTVIN High Byte
> > + * forms the 13-bit count value. If MNTVIN High
> > + * Byte readout is read successively, the
> > + * NCT7201/NCT7202 will latch the MNTVIN Low Byte
> > + * for next read.
> > + */
> > + v1 = nct720x_read_reg(chip, REG_VIN[index]);
> > + if (v1 < 0) {
> > + err = v1;
> > + goto abort;
> > + }
> > +
> > + v2 = nct720x_read_reg(chip, REG_VOLT_LOW_BYTE);
> > + if (v2 < 0) {
> > + err = v2;
> > + goto abort;
> > + }
> > + volt = (v1 << 8) | v2; /* Convert back to 16-bit value */
> > + } else {
> > + /* NCT7201/NCT7202 also supports read word-size data */
> > + volt = nct720x_read_word_swapped_reg(chip, REG_VIN[index]);
> > + }
> > +
> > + /* Voltage(V) = 13bitCountValue * 0.0004995 */
> > + volt = (volt >> 3) * NCT720X_IN_SCALING;
> > + *val = volt / 10000;
> > + mutex_unlock(&chip->access_lock);
> > + return IIO_VAL_INT;
> > + default:
> > + return -EINVAL;
> > + }
> > +abort:
> > + mutex_unlock(&chip->access_lock);
> > + return err;
> > +}
> > +
> > +static int nct720x_read_event_value(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info,
> > + int *val, int *val2)
> > +{
> > + struct nct720x_chip_info *chip = iio_priv(indio_dev);
> > + int v1, v2, err;
> > + int volt = 0;
> > + int index = nct720x_chan_to_index[chan->address];
> > +
> > + if (chan->type != IIO_VOLTAGE)
> > + return -EOPNOTSUPP;
> > +
> > + if (info == IIO_EV_INFO_VALUE) {
> > + if (dir == IIO_EV_DIR_FALLING) {
> > + if (chip->use_read_byte_vin) {
> > + /*
> > + * Low limit VIN Low Byte together with Low limit VIN High Byte
> > + forms the 13-bit count value
> > + */
> > + mutex_lock(&chip->access_lock);
> > + v1 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT[index]);
> > + if (v1 < 0) {
> > + err = v1;
> > + goto abort;
> > + }
> > +
> > + v2 = nct720x_read_reg(chip, REG_VIN_LOW_LIMIT_LSB[index]);
> > + if (v2 < 0) {
> > + err = v2;
> > + goto abort;
> > + }
> > + mutex_unlock(&chip->access_lock);
> > + volt = (v1 << 8) | v2; /* Convert back to 16-bit value */
> > + } else {
> > + /* NCT7201/NCT7202 also supports read word-size data */
> > + volt = nct720x_read_word_swapped_reg(chip,
> > + REG_VIN_LOW_LIMIT[index]);
> > + }
> > + } else {
> > + if (chip->use_read_byte_vin) {
> > + /*
> > + * High limit VIN Low Byte together with high limit VIN High Byte
> > + * forms the 13-bit count value
> > + */
> > + mutex_lock(&chip->access_lock);
> > + v1 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT[index]);
> > + if (v1 < 0) {
> > + err = v1;
> > + goto abort;
> > + }
> > +
> > + v2 = nct720x_read_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index]);
> > + if (v2 < 0) {
> > + err = v2;
> > + goto abort;
> > + }
> > + mutex_unlock(&chip->access_lock);
> > + volt = (v1 << 8) | v2; /* Convert back to 16-bit value */
> > + } else {
> > + /* NCT7201/NCT7202 also supports read word-size data */
> > + volt = nct720x_read_word_swapped_reg(chip,
> > + REG_VIN_HIGH_LIMIT[index]);
> > + }
> > + }
> > + }
> > + /* Voltage(V) = 13bitCountValue * 0.0004995 */
> > + volt = (volt >> 3) * NCT720X_IN_SCALING;
> > + *val = volt / 10000;
> > +
> > + return IIO_VAL_INT;
> > +abort:
> > + mutex_unlock(&chip->access_lock);
> > + return err;
> > +}
> > +
> > +static int nct720x_write_event_value(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + enum iio_event_info info,
> > + int val, int val2)
> > +{
> > + struct nct720x_chip_info *chip = iio_priv(indio_dev);
> > + int index, err = 0;
> > + long v1, v2, volt;
> > +
> > + index = nct720x_chan_to_index[chan->address];
> > + volt = (val * 10000) / NCT720X_IN_SCALING;
> > + v1 = volt >> 5;
> > + v2 = (volt & 0x1f) << 3;
> > +
> > + if (chan->type != IIO_VOLTAGE)
> > + return -EOPNOTSUPP;
> > +
> > + if (info == IIO_EV_INFO_VALUE) {
> > + if (dir == IIO_EV_DIR_FALLING) {
> > + mutex_lock(&chip->access_lock);
> > + err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT[index], v1);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_VIN%d_LOW_LIMIT\n", index + 1);
> > + goto abort;
> > + }
> > +
> > + err = nct720x_write_reg(chip, REG_VIN_LOW_LIMIT_LSB[index], v2);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_VIN%d_LOW_LIMIT_LSB\n", index + 1);
> > + goto abort;
> > + }
> > + } else {
> > + mutex_lock(&chip->access_lock);
> > + err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT[index], v1);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_VIN%d_HIGH_LIMIT\n", index + 1);
> > + goto abort;
> > + }
> > +
> > + err = nct720x_write_reg(chip, REG_VIN_HIGH_LIMIT_LSB[index], v2);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_VIN%d_HIGH_LIMIT_LSB\n", index + 1);
> > + goto abort;
> > + }
> > + }
> > + }
> > +abort:
> > + mutex_unlock(&chip->access_lock);
> > + return err;
> > +}
> > +
> > +static int nct720x_read_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir)
> > +{
> > + struct nct720x_chip_info *chip = iio_priv(indio_dev);
> > + int index = nct720x_chan_to_index[chan->address];
> > +
> > + if (chan->type != IIO_VOLTAGE)
> > + return -EOPNOTSUPP;
> > +
> > + return !!(chip->vin_mask & BIT(index));
> > +}
> > +
> > +static int nct720x_write_event_config(struct iio_dev *indio_dev,
> > + const struct iio_chan_spec *chan,
> > + enum iio_event_type type,
> > + enum iio_event_direction dir,
> > + int state)
> > +{
> > + int err = 0;
> > + struct nct720x_chip_info *chip = iio_priv(indio_dev);
> > + int index = nct720x_chan_to_index[chan->address];
> > + unsigned int mask;
> > +
> > + mask = BIT(index);
>
> nitpick:
> You can set the mask near to the place where it is used i.e.
> just after below if statement and one added advantage will
> be in case below "return -EOPNOTSUPP" gets executed,
> you don't even have to set mask.
>
Got it.
> > +
> > + if (chan->type != IIO_VOLTAGE)
> > + return -EOPNOTSUPP;
> > +
> > + if (!state && (chip->vin_mask & mask))
> > + chip->vin_mask &= ~mask;
> > + else if (state && !(chip->vin_mask & mask))
> > + chip->vin_mask |= mask;
> > +
> > + mutex_lock(&chip->access_lock);
> > +
> > + err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, chip->vin_mask & 0xff);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
> > + goto abort;
> > + }
> > +
> > + if (chip->type == nct7202) {
> > + err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, chip->vin_mask >> 8);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
> > + goto abort;
> > + }
> > + }
> > +abort:
> > + mutex_unlock(&chip->access_lock);
> > + return err;
> > +}
> > +
> > +static int nct720x_detect(struct i2c_client *client,
> > + struct i2c_board_info *info)
> > +{
> > + struct i2c_adapter *adapter = client->adapter;
> > +
> > + if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
> > + I2C_FUNC_SMBUS_WORD_DATA))
> > + return -ENODEV;
> > +
> > + /* Determine the chip type. */
> > + if (i2c_smbus_read_byte_data(client, REG_VENDOR_ID) != NUVOTON_ID ||
> > + i2c_smbus_read_byte_data(client, REG_CHIP_ID) != NCT720X_ID ||
> > + i2c_smbus_read_byte_data(client, REG_DEVICE_ID) != NCT720X_DEVICE_ID)
> > + return -ENODEV;
> > +
> > + strscpy(info->type, "nct720x", I2C_NAME_SIZE);
> > +
> > + return 0;
> > +}
> > +
> > +static const struct iio_info nct720x_info = {
> > + .read_raw = &nct720x_read_raw,
> > + .read_event_config = &nct720x_read_event_config,
> > + .write_event_config = &nct720x_write_event_config,
> > + .read_event_value = &nct720x_read_event_value,
> > + .write_event_value = &nct720x_write_event_value,
> > +};
> > +
> > +static const struct i2c_device_id nct720x_id[];
> > +
> > +static int nct720x_init_chip(struct nct720x_chip_info *chip)
> > +{
> > + int value = 0;
> > + int err = 0;
>
> Nit pick:
> You don't need to initialize err and value.
>
Got it.
> > +
> > + /* Initial reset */
> > + err = nct720x_write_reg(chip, REG_CONFIGURATION, CONFIGURATION_INIT);
> > + if (err) {
> > + pr_err("Failed to write REG_CONFIGURATION\n");
> > + return err;
> > + }
> > +
> > + /* Enable Channel */
> > + err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_1, 0xff);
> > + if (err) {
> > + pr_err("Failed to write REG_CHANNEL_ENABLE_1\n");
> > + return err;
> > + }
> > +
> > + if (chip->type == nct7202) {
> > + err = nct720x_write_reg(chip, REG_CHANNEL_ENABLE_2, 0xf);
> > + if (err) {
> > + pr_err("Failed to write REG_CHANNEL_ENABLE_2\n");
> > + return err;
> > + }
> > + }
> > +
> > + value = nct720x_read_reg16(chip, REG_CHANNEL_ENABLE_1);
> > + if (value < 0)
> > + return value;
> > + chip->vin_mask = value;
> > +
> > + /* Start monitoring if needed */
> > + value = nct720x_read_reg(chip, REG_CONFIGURATION);
> > + if (value < 0) {
> > + pr_err("Failed to read REG_CONFIGURATION\n");
> > + return value;
> > + }
> > +
> > + value |= CONFIGURATION_START;
> > + err = nct720x_write_reg(chip, REG_CONFIGURATION, value);
> > + if (err < 0) {
> > + pr_err("Failed to write REG_CONFIGURATION\n");
> > + return err;
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +static int nct720x_probe(struct i2c_client *client)
> > +{
> > + const struct i2c_device_id *id = i2c_client_get_device_id(client);
> > + struct nct720x_chip_info *chip;
> > + struct iio_dev *indio_dev;
> > + int ret;
> > + u32 tmp;
> > +
> > + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
> > + if (!indio_dev)
> > + return -ENOMEM;
> > + chip = iio_priv(indio_dev);
> > +
> > + if (client->dev.of_node)
> > + chip->type = (enum nct720x_chips)device_get_match_data(&client->dev);
> > + else
> > + chip->type = i2c_match_id(nct720x_id, client)->driver_data;
> > +
> > + chip->vin_max = (chip->type == nct7201) ? NCT7201_VIN_MAX : NCT7202_VIN_MAX;
> > +
> > + ret = of_property_read_u32(client->dev.of_node, "read-vin-data-size", &tmp);
> > + if (ret < 0) {
> > + pr_err("read-vin-data-size property not found\n");
> > + return ret;
>
> nit: dev_err_probe
>
I would use dev_err_probe to replace pr_err in probe function
> > + }
> > +
> > + if (tmp == 8) {
> > + chip->use_read_byte_vin = true;
> > + } else if (tmp == 16) {
> > + chip->use_read_byte_vin = false;
> > + } else {
> > + pr_err("invalid read-vin-data-size (%d)\n", tmp);
> > + return -EINVAL;
>
> nit: dev_err_probe
>
I would use dev_err_probe to replace pr_err in probe function.
> > + }
> > +
> > + mutex_init(&chip->access_lock);
> > +
> > + /* this is only used for device removal purposes */
> > + i2c_set_clientdata(client, indio_dev);
> > +
> > + chip->client = client;
> > +
> > + ret = nct720x_init_chip(chip);
> > + if (ret < 0)
> > + return ret;
> > +
> > + indio_dev->name = id->name;
> > + indio_dev->channels = nct720x_channels;
> > + indio_dev->num_channels = ARRAY_SIZE(nct720x_channels);
> > + indio_dev->info = &nct720x_info;
> > + indio_dev->modes = INDIO_DIRECT_MODE;
> > +
> > + iio_device_register(indio_dev);
>
> devm_iio_device_register?
>
Yes, I would use devm_iio_device_registe to replace
iio_device_register and no need to use remove function.
> > +
> > + return 0;
> > +}
> > +
> > +static void nct720x_remove(struct i2c_client *client)
> > +{
> > + struct iio_dev *indio_dev = i2c_get_clientdata(client);
> > +
> > + iio_device_unregister(indio_dev);
>
> wouldn't need if used devm_ version
Got it.
> > +}
> > +
> > +static const unsigned short nct720x_address_list[] = {
> > + 0x1d, 0x1e, 0x35, 0x36, I2C_CLIENT_END
> > +};
> > +
> > +static const struct i2c_device_id nct720x_id[] = {
> > + { "nct7201", nct7201 },
> > + { "nct7202", nct7202 },
> > + {}
> > +};
> > +MODULE_DEVICE_TABLE(i2c, nct720x_id);
> > +
> > +static const struct of_device_id nct720x_of_match[] = {
> > + {
> > + .compatible = "nuvoton,nct7201",
> > + .data = (void *)nct7201
> > + },
> > + {
> > + .compatible = "nuvoton,nct7202",
> > + .data = (void *)nct7202
> > + },
> > + { },
> > +};
> > +
> > +MODULE_DEVICE_TABLE(of, nct720x_of_match);
> > +
> > +static struct i2c_driver nct720x_driver = {
> > + .driver = {
> > + .name = "nct720x",
> > + .of_match_table = nct720x_of_match,
> > + },
> > + .probe = nct720x_probe,
> > + .remove = nct720x_remove,
> > + .id_table = nct720x_id,
> > + .detect = nct720x_detect,
> > + .address_list = nct720x_address_list,
> > +};
> > +
> > +module_i2c_driver(nct720x_driver);
> > +
> > +MODULE_AUTHOR("Eason Yang <YHYANG2 at nuvoton.com>");
> > +MODULE_DESCRIPTION("Nuvoton NCT720x voltage monitor driver");
> > +MODULE_LICENSE("GPL");
> > --
> > 2.34.1
> >
> >
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