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Message-ID: <20211028165847.4baa8566@jic23-huawei>
Date: Thu, 28 Oct 2021 16:58:47 +0100
From: Jonathan Cameron <jic23@...nel.org>
To: Cosmin Tanislav <demonsingur@...il.com>
Cc: cosmin.tanislav@...log.com, Lars-Peter Clausen <lars@...afoo.de>,
Michael Hennerich <Michael.Hennerich@...log.com>,
Rob Herring <robh+dt@...nel.org>, linux-iio@...r.kernel.org,
devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
Linus Walleij <linus.walleij@...aro.org>,
Bartosz Golaszewski <brgl@...ev.pl>, linux-gpio@...r.kernel.org
Subject: Re: [PATCH 3/3] iio: addac: add AD74413R driver
On Thu, 28 Oct 2021 16:48:45 +0300
Cosmin Tanislav <demonsingur@...il.com> wrote:
> Add IIO ADDAC driver for AD74413R.
Hi Cosmin,
+CC gpio people given this is also a gpio chip driver.
As for the binding, it's nice to have a little more in the patch description.
Here it would be good to see something about what features are supported
by the driver for example.
For a series like this I'd also suggest using a cover letter. That both
provides a good place to put general comments and also a good place for
people to give tags for the whole series.
Comments inline. I've left the whole code here this time so that
it is visible to those I added to the cc list.
Thanks,
Jonathan
>
> Signed-off-by: Cosmin Tanislav <cosmin.tanislav@...log.com>
> ---
> MAINTAINERS | 9 +
> drivers/iio/addac/Kconfig | 12 +
> drivers/iio/addac/Makefile | 1 +
> drivers/iio/addac/ad74413r.c | 1389 ++++++++++++++++++++++++++++++++++
> 4 files changed, 1411 insertions(+)
> create mode 100644 drivers/iio/addac/ad74413r.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 37982beaf91f..174f0fd3d71c 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1069,6 +1069,15 @@ W: http://ez.analog.com/community/linux-device-drivers
> F: Documentation/devicetree/bindings/iio/adc/adi,ad7780.yaml
> F: drivers/iio/adc/ad7780.c
>
> +ANALOG DEVICES INC AD74413R DRIVER
> +M: Cosmin Tanislav <cosmin.tanislav@...log.com>
> +L: linux-iio@...r.kernel.org
> +S: Supported
> +W: http://ez.analog.com/community/linux-device-drivers
> +F: Documentation/devicetree/bindings/iio/addac/adi,ad74413r.yaml
> +F: drivers/iio/addac/ad74413r.c
> +F: include/dt-bindings/iio/addac/adi,ad74413r.h
> +
> ANALOG DEVICES INC AD9389B DRIVER
> M: Hans Verkuil <hverkuil-cisco@...all.nl>
> L: linux-media@...r.kernel.org
> diff --git a/drivers/iio/addac/Kconfig b/drivers/iio/addac/Kconfig
> index 2e64d7755d5e..06b26f8d0144 100644
> --- a/drivers/iio/addac/Kconfig
> +++ b/drivers/iio/addac/Kconfig
> @@ -5,4 +5,16 @@
>
> menu "Analog to digital and digital to analog converters"
>
> +config AD74413R
> + tristate "Analog Devices AD74413R/AD74412R driver"
> + depends on GPIOLIB && SPI
> + select REGMAP_SPI
> + select CRC8
> + help
> + Say yes here to build support for Analog Devices AD74413R/AD74412R
> + quad-channel software configurable input/output solution.
> +
> + To compile this driver as a module, choose M here: the
> + module will be called ad74413r.
> +
> endmenu
> diff --git a/drivers/iio/addac/Makefile b/drivers/iio/addac/Makefile
> index b888b9ee12da..cfd4bbe64ad3 100644
> --- a/drivers/iio/addac/Makefile
> +++ b/drivers/iio/addac/Makefile
> @@ -4,3 +4,4 @@
> #
>
> # When adding new entries keep the list in alphabetical order
> +obj-$(CONFIG_AD74413R) += ad74413r.o
> diff --git a/drivers/iio/addac/ad74413r.c b/drivers/iio/addac/ad74413r.c
> new file mode 100644
> index 000000000000..76d2e09a17ee
> --- /dev/null
> +++ b/drivers/iio/addac/ad74413r.c
> @@ -0,0 +1,1389 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2021 Analog Devices, Inc.
> + * Author: Cosmin Tanislav <cosmin.tanislav@...log.com>
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/crc8.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +#include <linux/interrupt.h>
> +#include <linux/module.h>
mod_devicetable.h
> +#include <linux/of.h>
> +#include <linux/of_device.h>
We are attempting to move all new drivers (and many old ones)
over to the generic firmware interfaces in linux/property.h
as that gives us support for other firmware types more or less for
free.
> +#include <linux/regmap.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/spi/spi.h>
> +
> +#include <dt-bindings/iio/addac/adi,ad74413r.h>
> +
> +#define AD74413R_CRC_POLYNOMIAL 0x7
> +DECLARE_CRC8_TABLE(ad74413r_crc8_table);
> +
> +#define AD74413R_CHANNEL_MAX 4
> +
> +struct ad74413r_config {
> + bool hart_support;
> +};
> +
> +struct ad74413r_channel_config {
> + u32 gpo_config;
> + u32 func;
> + bool initialized;
> +};
> +
> +struct ad74413r_state {
> + struct ad74413r_channel_config channel_configs[AD74413R_CHANNEL_MAX];
> + struct gpio_chip gpiochip;
> + struct mutex lock;
> + struct completion adc_data_completion;
> +
> + struct spi_device *spi;
> + struct iio_dev *indio_dev;
> + struct regulator *refin_reg;
> + struct regmap *regmap;
> + struct device *dev;
> + struct iio_trigger *trig;
> + const struct ad74413r_config *config;
> +
> + u32 rsense_resistance_ohms;
> +
> + size_t adc_active_channels;
> + struct spi_message adc_samples_msg;
> + struct spi_transfer adc_samples_xfer[AD74413R_CHANNEL_MAX + 1];
> + struct {
> + __be32 rx_buf[AD74413R_CHANNEL_MAX];
> + s64 timestamp;
> + } adc_samples ____cacheline_aligned;
I would add a comment somewhere here to say you are using this single ____cacheline_aligned
element to ensure that all these buffers don't share a cacheline with anything esle.
It doesn't matter that they share space with each other.
> + __be32 adc_samples_tx_buf[AD74413R_CHANNEL_MAX];
> + __be32 regmap_tx_buf;
> + __be32 regmap_rx_buf;
> +};
> +
> +#define AD74413R_REG_NOP 0x00
> +
> +#define AD74413R_REG_CH_FUNC_SETUP_X(x) (0x01 + (x))
> +#define AD74413R_CH_FUNC_SETUP_MASK GENMASK(3, 0)
> +
> +#define AD74413R_REG_ADC_CONFIG_X(x) (0x05 + (x))
> +#define AD74413R_ADC_CONFIG_RANGE_MASK GENMASK(7, 5)
> +#define AD74413R_ADC_CONFIG_REJECTION_MASK GENMASK(4, 3)
> +#define AD74413R_ADC_RANGE_10V 0b000
> +#define AD74413R_ADC_RANGE_2P5V_EXT_POW 0b001
> +#define AD74413R_ADC_RANGE_2P5V_INT_POW 0b010
> +#define AD74413R_ADC_RANGE_5V_BI_DIR 0b011
> +#define AD74413R_ADC_REJECTION_50_60 0b00
> +#define AD74413R_ADC_REJECTION_NONE 0b01
> +#define AD74413R_ADC_REJECTION_50_60_HART 0b10
> +#define AD74413R_ADC_REJECTION_HART 0b11
> +
> +#define AD74413R_REG_DAC_CODE_X(x) (0x16 + (x))
> +#define AD74413R_DAC_CODE_MAX ((1 << 13) - 1)
> +
> +#define AD74413R_REG_GPO_PAR_DATA 0x0d
> +#define AD74413R_REG_GPO_CONFIG_X(x) (0x0e + (x))
> +#define AD74413R_GPO_CONFIG_GPO_DATA_MASK BIT(3)
> +#define AD74413R_GPO_CONFIG_DATA_LOW 0
> +#define AD74413R_GPO_CONFIG_DATA_HIGH AD74413R_GPO_CONFIG_GPO_DATA_MASK
> +#define AD74413R_GPO_CONFIG_GPO_SELECT_MASK GENMASK(2, 0)
> +
> +#define AD74413R_REG_ADC_CONV_CTRL 0x23
> +#define AD74413R_CONV_SEQ_MASK GENMASK(9, 8)
> +#define AD74413R_CONV_SEQ_ON 0b00
> +#define AD74413R_CONV_SEQ_SINGLE 0b01
> +#define AD74413R_CONV_SEQ_CONTINUOUS 0b10
> +#define AD74413R_CONV_SEQ_OFF 0b11
> +#define AD74413R_CH_EN_MASK(x) BIT(x)
> +#define AD74413R_CH_EN_SHIFT(x) x
> +
> +#define AD74413R_REG_DIN_COMP_OUT 0x25
> +#define AD74413R_DIN_COMP_OUT_MASK_X(x) BIT(x)
> +#define AD74413R_DIN_COMP_OUT_SHIFT_X(x) x
> +
> +#define AD74413R_REG_ADC_RESULT_X(x) (0x26 + (x))
> +#define AD74413R_ADC_RESULT_MAX ((1 << 16) - 1)
> +
> +#define AD74413R_REG_READ_SELECT 0x41
> +
> +#define AD74413R_REG_CMD_KEY 0x44
> +#define AD74413R_CMD_KEY_LDAC 0x953a
> +
> +#define AD74413R_REG_SILLICON_REV 0x46
> +#define AD74413R_SILLICON_REV_ID_MASK GENMASK(7, 0)
> +#define AD74413R_SILLICON_REV_ID_EXPECTED 0x8
> +
> +#define AD74413R_ADC_DATA_TIMEOUT 1000
> +
> +static const int ad74413r_adc_sampling_rates[] = {
> + 20,
> + 4800,
> +};
> +
> +static const int ad74413r_adc_sampling_rates_hart[] = {
> + 10,
> + 20,
> + 1200,
> + 4800,
> +};
> +
> +static int ad74413r_crc(u8 *buf)
> +{
> + return crc8(ad74413r_crc8_table, buf, 3, 0);
> +}
> +
> +static void ad74413r_format_reg_write(unsigned int reg, unsigned int val, u8 *buf)
> +{
> + buf[0] = reg & 0xff;
As it's a u8, why not make the parameter the right type?
> + buf[1] = (val >> 8) & 0xff;
put_unaligned_be16()
> + buf[2] = val & 0xff;
> + buf[3] = ad74413r_crc(buf);
> +}
> +
> +static int ad74413r_reg_write(void *context, unsigned int reg, unsigned int val)
> +{
> + struct device *dev = context;
> + struct spi_device *spi = to_spi_device(dev);
> + struct ad74413r_state *st = spi_get_drvdata(spi);
> + u8 *buf = (u8 *)&st->regmap_tx_buf;
> +
> + ad74413r_format_reg_write(reg, val, buf);
> +
> + return spi_write(spi, buf, 4);
> +}
> +
> +static int ad74413r_crc_check(struct ad74413r_state *st, u8 *buf)
> +{
> + u8 expected_crc = ad74413r_crc(buf);
> +
> + if (buf[3] != expected_crc) {
> + dev_err(st->dev, "Bad CRC, data: %02x%02x%02x, expected: %02x, received: %02x\n",
> + buf[0], buf[1], buf[2], expected_crc, buf[3]);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int ad74413r_reg_read_raw(void *context, unsigned int reg, u8 *buf,
> + unsigned int count)
> +{
> + struct device *dev = context;
Taking the raw device doesn't make much sense here. Make it take a type
parameter and a more useful one at that.
> + struct spi_device *spi = to_spi_device(dev);
> + struct ad74413r_state *st = spi_get_drvdata(spi);
> + unsigned int i;
> + int ret;
> +
> + ret = ad74413r_reg_write(context, AD74413R_REG_READ_SELECT, reg);
> + if (ret) {
> + dev_err(dev, "Failed to write read select register: %d\n", ret);
> + return ret;
> + }
> +
> + for (i = 0; i < count; i++, buf += 4) {
> + ret = spi_read(spi, buf, 4);
> + if (ret)
> + return ret;
> +
> + ret = ad74413r_crc_check(st, buf);
> + if (ret)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static int ad74413r_reg_read(void *context, unsigned int reg, unsigned int *val)
> +{
> + struct device *dev = context;
> + struct spi_device *spi = to_spi_device(dev);
> + struct ad74413r_state *st = spi_get_drvdata(spi);
> + u8 *buf = (u8 *)&st->regmap_rx_buf;
> + int ret;
> +
> + ret = ad74413r_reg_read_raw(context, reg, buf, 1);
> + if (ret)
> + return ret;
> +
> + *val = (buf[1] << 8) | buf[2];
get_unaligned_be16()
> +
> + return 0;
> +}
> +
> +const struct regmap_config ad74413r_regmap_config = {
> + .reg_bits = 8,
> + .val_bits = 16,
> + .reg_read = ad74413r_reg_read,
> + .reg_write = ad74413r_reg_write,
> +};
> +
> +static int ad74413r_set_gpo_mode(struct ad74413r_state *st, unsigned int offset, u8 mode)
> +{
> + if (mode < GPO_CONFIG_MIN || mode > GPO_CONFIG_MAX) {
> + dev_err(st->dev, "Invalid gpo config select mode\n");
Can we avoid getting here with values that will trigger this?
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(st->regmap, AD74413R_REG_GPO_CONFIG_X(offset),
> + AD74413R_GPO_CONFIG_GPO_SELECT_MASK, mode);
> +}
> +
> +static void ad74413r_gpio_set(struct gpio_chip *chip, unsigned int offset, int val)
> +{
> + struct ad74413r_state *st = gpiochip_get_data(chip);
> + struct ad74413r_channel_config *channel_config = &st->channel_configs[offset];
> + int ret;
> +
> + if (channel_config->gpo_config != GPO_CONFIG_LOGIC) {
> + dev_err(st->dev, "Cannot set gpo %u, not in logic mode", offset);
> + return;
> + }
> +
> + ret = ad74413r_set_gpo_mode(st, offset, GPO_CONFIG_LOGIC);
> + if (ret)
> + return;
> +
> + regmap_update_bits(st->regmap, AD74413R_REG_GPO_CONFIG_X(offset),
> + AD74413R_GPO_CONFIG_GPO_DATA_MASK,
> + val ? AD74413R_GPO_CONFIG_DATA_HIGH
> + : AD74413R_GPO_CONFIG_DATA_LOW);
> +}
> +
> +static void ad74413r_gpio_set_multiple(struct gpio_chip *chip, unsigned long *mask,
> + unsigned long *bits)
> +{
> + struct ad74413r_state *st = gpiochip_get_data(chip);
> + unsigned int offset = 0;
> + int ret;
> +
> + for_each_set_bit_from(offset, mask, AD74413R_CHANNEL_MAX) {
> + struct ad74413r_channel_config *channel_config = &st->channel_configs[offset];
> +
> + if (channel_config->gpo_config != GPO_CONFIG_LOGIC) {
> + dev_err(st->dev, "Cannot set gpo %u, not in logic mode\n", offset);
As below, this should be prevented at probe time not runtime.
> + continue;
> + }
> +
> + ret = ad74413r_set_gpo_mode(st, offset, GPO_CONFIG_LOGIC_PARALLEL);
> + if (ret)
> + return;
> + }
> +
> + regmap_update_bits(st->regmap, AD74413R_REG_GPO_PAR_DATA, *mask, *bits);
> +}
> +
> +static int ad74413r_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> + struct ad74413r_state *st = gpiochip_get_data(chip);
> + struct ad74413r_channel_config *channel_config = &st->channel_configs[offset];
> + unsigned int status;
> + int ret;
> +
> + if (channel_config->gpo_config != GPO_CONFIG_DEBOUNCED_COMPARATOR) {
> + dev_err(st->dev, "Cannot get gpo %u, not in comparator mode\n", offset);
Rule it out in the dt binding and enforce it at probe time not here which is far too late.
> + return -EINVAL;
> + }
> +
> + ret = regmap_read(st->regmap, AD74413R_REG_DIN_COMP_OUT, &status);
> + if (ret)
> + return ret;
> +
> + status &= AD74413R_DIN_COMP_OUT_MASK_X(offset);
> + status >>= AD74413R_DIN_COMP_OUT_SHIFT_X(offset);
As you are only checking one bit.
return status & BIT(offset);
If gpio needs a 0/1, then ? 1 : 0;
> +
> + return status;
> +}
> +
> +static int ad74413r_set_channel_dac_code(struct ad74413r_state *st, unsigned int channel,
> + uint16_t dac_code)
> +{
> + int ret;
> +
> + if (dac_code > AD74413R_DAC_CODE_MAX) {
> + dev_err(st->dev, "Invalid dac code %d\n", dac_code);
> + return -EINVAL;
> + }
> +
> + ret = regmap_write(st->regmap, AD74413R_REG_DAC_CODE_X(channel), dac_code);
> + if (ret)
> + return ret;
> +
> + ret = regmap_write(st->regmap, AD74413R_REG_CMD_KEY, AD74413R_CMD_KEY_LDAC);
> + if (ret)
> + return ret;
> +
> + return 0;
return regmap_write()
> +}
> +
> +static int ad74413r_channel_set_function(struct ad74413r_state *st, unsigned int channel, u8 func)
> +{
> + if (func < CH_FUNC_MIN || func > CH_FUNC_MAX) {
> + dev_err(st->dev, "Invalid channel function %d\n", func);
> + return -EINVAL;
> + }
> +
> + if (!st->config->hart_support && (func == CH_FUNC_CURRENT_INPUT_EXT_POWER_HART
> + || func == CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART)) {
> + dev_err(st->dev, "HART function not supported %d\n", func);
Move to caller perhaps? I'd not expect a function at this level to have to reject inputs.
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(st->regmap, AD74413R_REG_CH_FUNC_SETUP_X(channel),
> + AD74413R_CH_FUNC_SETUP_MASK, func);
> +}
> +
> +static int ad74413r_set_adc_conv_seq(struct ad74413r_state *st, unsigned int status)
> +{
> + int ret;
> +
> + /*
> + * These bits do not clear when a conversion completes.
> + * To enable a subsequent conversion, repeat the write to enable the conversion.
> + */
> + ret = regmap_write_bits(st->regmap, AD74413R_REG_ADC_CONV_CTRL,
> + AD74413R_CONV_SEQ_MASK,
> + FIELD_PREP(AD74413R_CONV_SEQ_MASK, status));
> + if (ret)
> + return ret;
> +
> + // Wait 100us before starting conversions
/* */ format for all comments in IIO (other than SPDX where there are cases that mean it has to be different...)
> + usleep_range(100, 120);
> +
> + return 0;
> +}
> +
> +static int ad74413r_set_adc_channel_enable(struct ad74413r_state *st, unsigned int channel,
> + bool status)
> +{
> + unsigned int val = status << AD74413R_CH_EN_SHIFT(channel);
> +
> + return regmap_update_bits(st->regmap, AD74413R_REG_ADC_CONV_CTRL,
> + AD74413R_CH_EN_MASK(channel), val);
> +}
> +
> +static int ad74413r_get_adc_range(struct ad74413r_state *st, unsigned int channel,
> + unsigned int *val)
> +{
> + int ret;
> +
> + ret = regmap_read(st->regmap, AD74413R_REG_ADC_CONFIG_X(channel), val);
> + if (ret)
> + return ret;
> +
> + *val = FIELD_GET(AD74413R_ADC_CONFIG_RANGE_MASK, *val);
> +
> + return 0;
> +}
> +
> +static int ad74413r_get_adc_rejection(struct ad74413r_state *st, unsigned int channel,
> + unsigned int *val)
> +{
> + int ret;
> +
> + ret = regmap_read(st->regmap, AD74413R_REG_ADC_CONFIG_X(channel), val);
> + if (ret)
> + return ret;
> +
> + *val = FIELD_GET(AD74413R_ADC_CONFIG_REJECTION_MASK, *val);
> +
> + return 0;
> +}
> +
> +static int ad74413r_set_adc_rejection(struct ad74413r_state *st, unsigned int channel,
> + unsigned int val)
> +{
> + if (!st->config->hart_support && (val == AD74413R_ADC_REJECTION_50_60_HART
> + || val == AD74413R_ADC_REJECTION_HART)) {
Perhaps makes more sense to move this check to the caller?
> + dev_err(st->dev, "HART rate not supported %d\n", val);
> + return -EINVAL;
> + }
> +
> + return regmap_update_bits(st->regmap, AD74413R_REG_ADC_CONFIG_X(channel),
> + AD74413R_ADC_CONFIG_REJECTION_MASK,
> + FIELD_PREP(AD74413R_ADC_CONFIG_REJECTION_MASK, val));
> +}
> +
> +static int ad74413r_get_adc_rate(struct ad74413r_state *st, unsigned int channel, int *val)
> +{
> + unsigned int rej;
> + int ret;
> +
> + ret = ad74413r_get_adc_rejection(st, channel, &rej);
> + if (ret)
> + return ret;
> +
> + switch (rej) {
> + case AD74413R_ADC_REJECTION_50_60:
> + *val = 20;
> + break;
> + case AD74413R_ADC_REJECTION_NONE:
> + *val = 4800;
> + break;
> + case AD74413R_ADC_REJECTION_50_60_HART:
> + *val = 10;
> + break;
> + case AD74413R_ADC_REJECTION_HART:
> + *val = 1200;
> + break;
> + default:
> + dev_err(st->dev, "Channel %u ADC rejection invalid\n", channel);
> + return -EINVAL;
> + }
> +
> + return IIO_VAL_INT;
> +}
> +
> +static int ad74413r_set_adc_rate(struct ad74413r_state *st, unsigned int channel, int val)
> +{
> + unsigned int rej;
> +
> + switch (val) {
> + case 20:
> + rej = AD74413R_ADC_REJECTION_50_60;
> + break;
> + case 4800:
> + rej = AD74413R_ADC_REJECTION_NONE;
> + break;
> + case 10:
> + rej = AD74413R_ADC_REJECTION_50_60_HART;
> + break;
> + case 1200:
> + rej = AD74413R_ADC_REJECTION_HART;
> + break;
> + default:
> + dev_err(st->dev, "Channel %u ADC rate invalid\n", channel);
> + return -EINVAL;
> + }
> +
> + return ad74413r_set_adc_rejection(st, channel, rej);
> +}
> +
> +static int ad74413r_get_adc_voltage_range(struct ad74413r_state *st, unsigned int channel,
> + int *val)
> +{
> + unsigned int range;
> + int ret;
> +
> + ret = ad74413r_get_adc_range(st, channel, &range);
> + if (ret)
> + return ret;
> +
> + switch (range) {
> + case AD74413R_ADC_RANGE_10V:
> + *val = 10000;
> + break;
> + case AD74413R_ADC_RANGE_2P5V_EXT_POW:
> + case AD74413R_ADC_RANGE_2P5V_INT_POW:
> + *val = 2500;
> + break;
> + case AD74413R_ADC_RANGE_5V_BI_DIR:
> + *val = 5000;
> + break;
> + default:
> + dev_err(st->dev, "Channel %u ADC range invalid\n", channel);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int ad74413r_get_adc_voltage_offset(struct ad74413r_state *st, unsigned int channel,
> + int *val)
> +{
> + unsigned int range;
> + int ret;
> +
> + ret = ad74413r_get_adc_range(st, channel, &range);
> + if (ret)
> + return ret;
> +
> + switch (range) {
> + case AD74413R_ADC_RANGE_10V:
> + case AD74413R_ADC_RANGE_2P5V_EXT_POW:
> + *val = 0;
> + break;
> + case AD74413R_ADC_RANGE_2P5V_INT_POW:
> + case AD74413R_ADC_RANGE_5V_BI_DIR:
> + *val = -2500;
> + break;
> + default:
> + dev_err(st->dev, "Channel %u ADC range invalid\n", channel);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int ad74413r_get_input_voltage_scale(struct ad74413r_state *st, unsigned int channel,
> + int *val, int *val2)
> +{
> + int ret;
> +
> + ret = ad74413r_get_adc_voltage_range(st, channel, val);
> + if (ret)
> + return ret;
> +
> + *val2 = AD74413R_ADC_RESULT_MAX;
interesting. Often these are 1/(N**2) rather than 1/(N**2 - 1) as here.
Noise level is probably high enough this doesn't really matter though.
Data sheets are never entirely clear if ranges are inclusive or not...
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int ad74413r_get_input_voltage_offset(struct ad74413r_state *st, unsigned int channel,
> + int *val, int *val2)
> +{
> + unsigned int range;
> + int ret;
> +
> + ret = ad74413r_get_adc_range(st, channel, &range);
> + if (ret)
> + return ret;
> +
> + switch (range) {
> + case AD74413R_ADC_RANGE_10V:
> + case AD74413R_ADC_RANGE_2P5V_EXT_POW:
> + *val = 0;
> + break;
> + case AD74413R_ADC_RANGE_2P5V_INT_POW:
> + *val = -AD74413R_ADC_RESULT_MAX;
> + break;
> + case AD74413R_ADC_RANGE_5V_BI_DIR:
> + *val = -AD74413R_ADC_RESULT_MAX / 2;
> + break;
> + default:
> + dev_err(st->dev, "Channel %u ADC range invalid\n", channel);
> + return -EINVAL;
> + }
> +
> + *val2 = 0;
As below.
> +
> + return IIO_VAL_INT;
> +}
> +
> +static int ad74413r_get_input_current_scale(struct ad74413r_state *st, unsigned int channel,
> + int *val, int *val2)
> +{
> + int ret;
> +
> + ret = ad74413r_get_adc_voltage_range(st, channel, val);
> + if (ret)
> + return ret;
> +
> + *val2 = AD74413R_ADC_RESULT_MAX * st->rsense_resistance_ohms;
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int ad74413_get_input_current_offset(struct ad74413r_state *st, unsigned int channel,
> + int *val, int *val2)
> +{
> + int range;
> + int offset;
> + int ret;
> +
> + ret = ad74413r_get_adc_voltage_range(st, channel, &range);
> + if (ret)
> + return ret;
> +
> + ret = ad74413r_get_adc_voltage_offset(st, channel, &offset);
> + if (ret)
> + return ret;
> +
> + *val = offset * AD74413R_ADC_RESULT_MAX / range;
> + *val2 = 0;
No need to set *val2 when IIO_VAL_INT being returned. The IIO core won't read it.
> +
> + return IIO_VAL_INT;
> +}
> +
> +static int ad74413r_get_output_voltage_scale(struct ad74413r_state *st,
> + int *val, int *val2)
> +{
> + *val = 11000;
> + *val2 = AD74413R_DAC_CODE_MAX;
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static int ad74413r_get_output_current_scale(struct ad74413r_state *st, int *val, int *val2)
> +{
> + *val = regulator_get_voltage(st->refin_reg);
> + *val2 = st->rsense_resistance_ohms * AD74413R_DAC_CODE_MAX * 1000;
> +
> + return IIO_VAL_FRACTIONAL;
> +}
> +
> +static irqreturn_t ad74413r_trigger_handler(int irq, void *p)
> +{
> + struct iio_poll_func *pf = p;
> + struct iio_dev *indio_dev = pf->indio_dev;
> + struct ad74413r_state *st = iio_priv(indio_dev);
> + unsigned int i;
> + int ret;
> +
> + mutex_lock(&st->lock);
> +
> + ret = spi_sync(st->spi, &st->adc_samples_msg);
> + if (ret)
> + goto out;
> +
> + for (i = 0; i < st->adc_active_channels; i++)
> + ad74413r_crc_check(st, (u8 *)&st->adc_samples.rx_buf[i]);
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, &st->adc_samples,
> + iio_get_time_ns(indio_dev));
> +
> +out:
> + iio_trigger_notify_done(indio_dev->trig);
> +
> + mutex_unlock(&st->lock);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static irqreturn_t ad74413r_adc_data_interrupt(int irq, void *data)
> +{
> + struct ad74413r_state *st = data;
> +
> + if (iio_buffer_enabled(st->indio_dev))
> + iio_trigger_poll(st->trig);
> + else
> + complete(&st->adc_data_completion);
> +
> + return IRQ_HANDLED;
> +}
> +
> +static int ad74413r_get_single_adc_result(struct ad74413r_state *st, unsigned int channel,
> + int *val)
> +{
> + unsigned int uval;
> + int ret;
> +
> + ret = iio_device_claim_direct_mode(st->indio_dev);
Pass indio_dev into these functions instead of st then navigate the other way
(which can be worked out at compile time rather than runtime).
> + if (ret)
> + return ret;
> +
> + reinit_completion(&st->adc_data_completion);
> +
> + ret = ad74413r_set_adc_channel_enable(st, channel, true);
> + if (ret)
> + goto out;
> +
> + ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_SINGLE);
> + if (ret)
> + goto out;
> +
> + ret = wait_for_completion_timeout(&st->adc_data_completion,
> + msecs_to_jiffies(AD74413R_ADC_DATA_TIMEOUT));
> + if (!ret) {
> + ret = -ETIMEDOUT;
> + goto out;
> + }
> +
> + ret = regmap_read(st->regmap, AD74413R_REG_ADC_RESULT_X(channel), &uval);
> + if (ret)
> + goto out;
> +
> + ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
> + if (ret)
> + goto out;
> +
> + ret = ad74413r_set_adc_channel_enable(st, channel, false);
> + if (ret)
> + goto out;
> +
> + *val = uval;
> + ret = IIO_VAL_INT;
> +
> +out:
> + iio_device_release_direct_mode(st->indio_dev);
hmm. You may have a potential deadlock here as mutex is taken outside of this
claim of direct_mode(). In update_scan_mode() you also take the mutex and that
can occur with the internal lock used for avoiding races in mode change also being
held. Hence you have lock inversion. IIRC the solution is to claim direct mode
before taking your local mutex. recent report for this for the dln2 adc driver.
https://lore.kernel.org/linux-iio/20211028153711.581fd9c8@jic23-huawei/T/#t
> +
> + return ret;
> +}
> +
> +static int ad74413r_get_single_resistance_result(struct ad74413r_state *st, unsigned int channel,
> + int *val)
> +{
> + unsigned int uval;
> + int ret;
> +
> + ret = ad74413r_get_single_adc_result(st, channel, &uval);
> + if (ret < 0)
> + return ret;
> +
> + if (uval == AD74413R_ADC_RESULT_MAX)
> + *val = 0;
> + else
> + *val = DIV_ROUND_CLOSEST(uval * 2100, AD74413R_ADC_RESULT_MAX - uval);
> +
> + return ret;
> +}
> +
> +static int ad74413r_update_scan_mode(struct iio_dev *indio_dev,
> + const unsigned long *active_scan_mask)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> + struct spi_transfer *xfer;
> + unsigned int channel;
> + int transfer_index = 0;
> + int ret;
> +
> + mutex_lock(&st->lock);
> +
> + spi_message_init(&st->adc_samples_msg);
> + st->adc_active_channels = 0;
> +
> + for (channel = 0; channel < AD74413R_CHANNEL_MAX; channel++) {
> + bool status = test_bit(channel, active_scan_mask);
Perhaps cleaner as a pair of loops for_each_set_bit() and for_each_clear_bit()
Something like.
for_each_clear_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
ret = ad74413r_set_adc_channel_enable, st, channel, false);
if (ret)
return ret;
}
for_each_set_bit(channel, active_scan_mask, AD74413R_CHANNEL_MAX) {
u8 *tx_buf;
ret = ad74413r_set_adc_cannel_enable, st, channel, true);
if (ret)
return ret;
st->adc_active_channels++;
xfer = &st->adc_samples_xfer[transfer_index];
if (transfer_index == 0)
xfer->rx_buf = NULL;
...
}
> + u8 *tx_buf;
> +
> + ret = ad74413r_set_adc_channel_enable(st, channel, status);
> + if (ret)
> + goto out;
> +
> + if (!status)
> + continue;
> +
> + st->adc_active_channels++;
> +
> + xfer = &st->adc_samples_xfer[transfer_index];
> +
> + if (transfer_index == 0)
> + xfer->rx_buf = NULL;
> + else
> + xfer->rx_buf = &st->adc_samples.rx_buf[transfer_index - 1];
> +
> + tx_buf = (u8 *)&st->adc_samples_tx_buf[transfer_index];
> +
> + xfer->tx_buf = tx_buf;
> + xfer->len = 4;
> + xfer->cs_change = 1;
> +
> + ad74413r_format_reg_write(AD74413R_REG_READ_SELECT,
> + AD74413R_REG_ADC_RESULT_X(channel),
> + tx_buf);
> +
> + spi_message_add_tail(xfer, &st->adc_samples_msg);
> +
> + transfer_index++;
> + }
> +
> + if (transfer_index == 0)
> + goto out;
> +
> + xfer = &st->adc_samples_xfer[transfer_index];
> +
> + xfer->tx_buf = NULL;
> + xfer->rx_buf = &st->adc_samples.rx_buf[transfer_index - 1];
> + xfer->len = 4;
> + xfer->cs_change = 0;
I guess this is a terminating message - add a comment on why it is needed.
> +
> + spi_message_add_tail(xfer, &st->adc_samples_msg);
> +
> +out:
> + mutex_unlock(&st->lock);
> +
> + return ret;
> +}
> +
> +static int ad74413r_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> +
> + return ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_CONTINUOUS);
> +}
> +
> +static int ad74413r_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> +
> + return ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
> +}
> +
> +static int ad74413r_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
> + int *val, int *val2, long info)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> + int ret = -EINVAL;
Whilst it is more code I'd prefer to see this set is explicitly in the error paths.
> +
> + mutex_lock(&st->lock);
It may be better to move this further down the tree so as to avoid locking in paths
were we aren't doing anything + to allow more direct returns avoiding the need
to read all the way to the end of the function to see what happens in a given path.
> +
> + switch (info) {
> + case IIO_CHAN_INFO_SCALE:
> + switch (chan->type) {
> + case IIO_ALTVOLTAGE:
> + if (chan->output)
> + ret = ad74413r_get_output_voltage_scale(st, val, val2);
> + else
> + ret = ad74413r_get_input_voltage_scale(st, chan->channel,
> + val, val2);
> + break;
> +
> + case IIO_CURRENT:
> + if (chan->output)
> + ret = ad74413r_get_output_current_scale(st, val, val2);
> + else
> + ret = ad74413r_get_input_current_scale(st, chan->channel,
> + val, val2);
> + break;
> + default:
> + break;
> + }
> + break;
> + case IIO_CHAN_INFO_OFFSET:
> + switch (chan->type) {
> + case IIO_ALTVOLTAGE:
> + if (!chan->output)
> + ret = ad74413r_get_input_voltage_offset(st, chan->channel,
> + val, val2);
> + break;
> + case IIO_CURRENT:
> + if (!chan->output)
> + ret = ad74413_get_input_current_offset(st, chan->channel,
> + val, val2);
> + break;
> + default:
> + break;
> + }
> + break;
> + case IIO_CHAN_INFO_RAW:
> + if (!chan->output)
> + ret = ad74413r_get_single_adc_result(st, chan->channel, val);
> + break;
> + case IIO_CHAN_INFO_PROCESSED:
> + switch (chan->type) {
> + case IIO_RESISTANCE:
> + if (!chan->output)
flip this to
if (chan->output) {
ret = -EINVAL;
break;
}
to reduce the indentation. Handling errors rather than good paths out of line of the main
flow is also easier to read.
> + ret = ad74413r_get_single_resistance_result(st, chan->channel,
> + val);
> + break;
> + default:
> + break;
> + }
> + break;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + if (!chan->output)
> + ret = ad74413r_get_adc_rate(st, chan->channel, val);
> + break;
> + default:
> + break;
> + }
> +
> + mutex_unlock(&st->lock);
> +
> + return ret;
> +}
> +
> +static int ad74413r_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
> + int val, int val2, long info)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> + int ret = -EINVAL;
> +
> + mutex_lock(&st->lock);
I would move the mutex into the individual branches. That will let you return
errors directly from all other paths which is easier to read.
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + switch (chan->type) {
> + case IIO_ALTVOLTAGE:
> + case IIO_CURRENT:
> + ret = ad74413r_set_channel_dac_code(st, chan->channel, val);
> + break;
> + default:
> + break;
> + }
> + break;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + if (!chan->output)
> + ret = ad74413r_set_adc_rate(st, chan->channel, val);
> + break;
> + default:
> + break;
> + }
> +
> + mutex_unlock(&st->lock);
> +
> + return ret;
> +}
> +
> +static int ad74413r_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
> + const int **vals, int *type, int *length, long info)
> +{
> + struct ad74413r_state *st = iio_priv(indio_dev);
> + int ret = -EINVAL;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + if (st->config->hart_support) {
> + *vals = ad74413r_adc_sampling_rates_hart;
> + *length = ARRAY_SIZE(ad74413r_adc_sampling_rates_hart);
> + } else {
> + *vals = ad74413r_adc_sampling_rates;
> + *length = ARRAY_SIZE(ad74413r_adc_sampling_rates);
> + }
> + *type = IIO_VAL_INT;
> + ret = IIO_AVAIL_LIST;
> + break;
> + default:
> + break;
> + }
> +
> + return ret;
put direct returns in the switch case statements rather than down here.
> +}
> +
> +static const struct iio_buffer_setup_ops ad74413r_buffer_ops = {
> + .postenable = &ad74413r_buffer_postenable,
> + .predisable = &ad74413r_buffer_predisable,
> +};
> +
> +static const struct iio_trigger_ops ad74413r_trigger_ops = {
> + .validate_device = iio_trigger_validate_own_device,
> +};
> +
> +static const struct iio_info ad74413r_info = {
> + .read_raw = &ad74413r_read_raw,
> + .write_raw = &ad74413r_write_raw,
> + .read_avail = &ad74413r_read_avail,
> + .update_scan_mode = &ad74413r_update_scan_mode,
> +};
> +
> +#define AD74413R_CHANNEL(_type, _output, extra_mask_separate) \
> + .type = _type, \
> + .indexed = 1, \
> + .output = _output, \
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | extra_mask_separate
> +
> +#define AD74413R_DAC_CHANNEL(_type, extra_mask_separate) \
> + { \
> + AD74413R_CHANNEL(_type, 1, extra_mask_separate), \
> + }
> +
> +#define AD74413R_ADC_CHANNEL(_type, extra_mask_separate) \
> + { \
> + AD74413R_CHANNEL(_type, 0, extra_mask_separate | BIT(IIO_CHAN_INFO_SAMP_FREQ)), \
> + .info_mask_shared_by_type_available = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
> + .scan_type = { \
> + .sign = 'u', \
> + .realbits = 16, \
> + .storagebits = 32, \
> + .shift = 8, \
> + .endianness = IIO_BE, \
> + }, \
> + }
> +
> +#define AD74413R_ADC_VOLTAGE_CHANNEL \
> + AD74413R_ADC_CHANNEL(IIO_ALTVOLTAGE, BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET))
> +
> +#define AD74413R_ADC_CURRENT_CHANNEL \
> + AD74413R_ADC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE) \
> + | BIT(IIO_CHAN_INFO_OFFSET))
> +
> +static struct iio_chan_spec ad74413r_high_impedance_channels[] = {
> + AD74413R_ADC_VOLTAGE_CHANNEL,
> +};
> +
> +static struct iio_chan_spec ad74413r_voltage_output_channels[] = {
> + AD74413R_DAC_CHANNEL(IIO_ALTVOLTAGE, BIT(IIO_CHAN_INFO_SCALE)),
> + AD74413R_ADC_CURRENT_CHANNEL,
These would benefit from explanatory comments as not obvious why a DAC
would have a paired ADC. I'm also curious why this is altvoltage
rather than voltage (DC).
> +};
> +
> +static struct iio_chan_spec ad74413r_current_output_channels[] = {
> + AD74413R_DAC_CHANNEL(IIO_CURRENT, BIT(IIO_CHAN_INFO_SCALE)),
> + AD74413R_ADC_VOLTAGE_CHANNEL,
> +};
> +
> +static struct iio_chan_spec ad74413r_voltage_input_channels[] = {
> + AD74413R_ADC_VOLTAGE_CHANNEL,
> +};
> +
> +static struct iio_chan_spec ad74413r_current_input_channels[] = {
> + AD74413R_ADC_CURRENT_CHANNEL,
> +};
> +
> +static struct iio_chan_spec ad74413r_resistance_input_channels[] = {
> + AD74413R_ADC_CHANNEL(IIO_RESISTANCE, BIT(IIO_CHAN_INFO_PROCESSED)),
> +};
> +
> +static struct iio_chan_spec ad74413r_digital_input_channels[] = {
> + AD74413R_ADC_VOLTAGE_CHANNEL,
> +};
> +
> +static int ad74413r_of_parse_channel_config(struct ad74413r_state *st,
> + struct device_node *channel_node)
> +{
> + struct ad74413r_channel_config *channel_config;
> + u32 index;
> + int ret;
> +
> + ret = of_property_read_u32(channel_node, "reg", &index);
Nothing in here looks to be device tree specific. Please change to using
the generic firmware property functions in include/linux/property.h
> + if (ret) {
> + dev_err(st->dev, "Failed to read channel reg: %d\n", ret);
> + return ret;
> + }
> +
> + if (index > AD74413R_CHANNEL_MAX) {
> + dev_err(st->dev, "Channel index %u is too large\n", index);
> + return -EINVAL;
> + }
> +
> + channel_config = &st->channel_configs[index];
> + if (channel_config->initialized) {
> + dev_err(st->dev, "Channel %u has already been initialized\n", index);
> + return -EINVAL;
> + }
> +
> + channel_config->func = CH_FUNC_HIGH_IMPEDANCE;
> + of_property_read_u32(channel_node, "adi,ch-func", &channel_config->func);
> +
> + channel_config->gpo_config = GPO_CONFIG_100K_PULL_DOWN;
> + of_property_read_u32(channel_node, "adi,gpo-config", &channel_config->gpo_config);
> +
> + if (channel_config->gpo_config == GPO_CONFIG_LOGIC_PARALLEL) {
> + dev_err(st->dev, "GPO config logic parallel is unsupported\n");
> + return -EINVAL;
Error out of this function is fine, but why not just leave this channel disabled
rather than failing to probe which I think is what will currently happen?
> + }
> +
> + ret = ad74413r_channel_set_function(st, index, channel_config->func);
> + if (ret)
> + return ret;
> +
> + ret = ad74413r_set_gpo_mode(st, index, channel_config->gpo_config);
Not all of these seem likely to be valid for all types of channel.
> + if (ret)
> + return ret;
> +
> + channel_config->initialized = true;
> +
> + return 0;
> +}
> +
> +static int ad74413r_parse_channel_configs(struct ad74413r_state *st)
> +{
> + struct device_node *channel_node = NULL;
> + int ret;
> +
> + for_each_available_child_of_node(st->dev->of_node, channel_node) {
> + if (!of_node_name_eq(channel_node, "channel"))
> + continue;
I'm not sure we should be doing this matching on node name. If you need
to do that, then add some sort of compatible rather than this.
> +
> + ret = ad74413r_of_parse_channel_config(st, channel_node);
> + if (ret) {
> + dev_err(st->dev, "Failed to parse channel %s config: %d\n",
> + channel_node->name, ret);
> + goto put_channel_node;
> + }
> + }
> +
> +put_channel_node:
> + of_node_put(channel_node);
I think you should only do this if you break out of the loop without finishing it -
so error path only.
> +
> + return ret;
> +}
> +
> +static int ad74413r_get_iio_channels(struct ad74413r_state *st, u8 func,
> + struct iio_chan_spec **iio_channels, unsigned int *count)
> +{
> + switch (func) {
> + case CH_FUNC_HIGH_IMPEDANCE:
Perhaps turn this function into an array lookup?
> + *iio_channels = ad74413r_high_impedance_channels;
> + *count = ARRAY_SIZE(ad74413r_high_impedance_channels);
> + break;
> + case CH_FUNC_VOLTAGE_OUTPUT:
> + *iio_channels = ad74413r_voltage_output_channels;
> + *count = ARRAY_SIZE(ad74413r_voltage_output_channels);
> + break;
> + case CH_FUNC_CURRENT_OUTPUT:
> + *iio_channels = ad74413r_current_output_channels;
> + *count = ARRAY_SIZE(ad74413r_current_output_channels);
> + break;
> + case CH_FUNC_VOLTAGE_INPUT:
> + *iio_channels = ad74413r_voltage_input_channels;
> + *count = ARRAY_SIZE(ad74413r_voltage_input_channels);
> + break;
> + case CH_FUNC_CURRENT_INPUT_EXT_POWER:
> + case CH_FUNC_CURRENT_INPUT_LOOP_POWER:
> + case CH_FUNC_CURRENT_INPUT_EXT_POWER_HART:
> + case CH_FUNC_CURRENT_INPUT_LOOP_POWER_HART:
> + *iio_channels = ad74413r_current_input_channels;
> + *count = ARRAY_SIZE(ad74413r_current_input_channels);
> + break;
> + case CH_FUNC_RESISTANCE_INPUT:
> + *iio_channels = ad74413r_resistance_input_channels;
> + *count = ARRAY_SIZE(ad74413r_resistance_input_channels);
> + break;
> + case CH_FUNC_DIGITAL_INPUT_LOGIC:
> + case CH_FUNC_DIGITAL_INPUT_LOOP_POWER:
> + *iio_channels = ad74413r_digital_input_channels;
> + *count = ARRAY_SIZE(ad74413r_digital_input_channels);
> + break;
> + default:
> + dev_err(st->dev, "Unhandled channel config function %d\n", func);
> + return -EINVAL;
> + }
> +
> + return 0;
return 0 where you break above so we don't have to look down here to find out what
happens.
> +}
> +
> +static int ad74413r_count_iio_channels(struct ad74413r_state *st)
> +{
> + unsigned int index;
> + int ret;
> +
> + st->indio_dev->num_channels = 0;
> +
> + for (index = 0; index < AD74413R_CHANNEL_MAX; index++) {
i works for a local index variable.
> + struct ad74413r_channel_config *channel_config = &st->channel_configs[index];
> + struct iio_chan_spec *local_channels;
> + unsigned int num_local_channels;
chans and num_chans are verbose enough names for these to not be confusing.
> +
> + ret = ad74413r_get_iio_channels(st, channel_config->func, &local_channels,
> + &num_local_channels);
> + if (ret)
> + return ret;
> +
> + st->indio_dev->num_channels += num_local_channels;
> + }
> +
> + return 0;
> +}
> +
> +static int ad74413r_setup_iio_channels(struct ad74413r_state *st)
Pass in the struct iio_dev, not st to avoid need for st->indio_dev
loop that you currently have.
> +{
> + struct iio_chan_spec *channels;
> + unsigned int index;
> + int ret;
> +
> + channels = devm_kcalloc(st->dev, sizeof(*channels),
> + st->indio_dev->num_channels, GFP_KERNEL);
> + if (!channels)
> + return -ENOMEM;
> +
> + st->indio_dev->channels = channels;
> +
> + for (index = 0; index < AD74413R_CHANNEL_MAX; index++) {
> + struct ad74413r_channel_config *channel_config = &st->channel_configs[index];
> + struct iio_chan_spec *local_channels;
> + unsigned int num_local_channels;
> + unsigned int chan_index;
> +
> + ret = ad74413r_get_iio_channels(st, channel_config->func, &local_channels,
> + &num_local_channels);
get usually implies some sort of reference count. Perhaps find is more appropriate?
> + if (ret)
> + return ret;
> +
> + memcpy(channels, local_channels, num_local_channels * sizeof(*local_channels));
Try to keep line lengths under 80 chars except where that would significantly hurt readability.
> +
> + for (chan_index = 0; chan_index < num_local_channels; chan_index++) {
> + struct iio_chan_spec *local_channel = &channels[chan_index];
local_chan is a long name for this - perhaps just call it chan
> +
> + local_channel->channel = index;
> + if (local_channel->output)
> + local_channel->scan_index = -1;
> + else
> + local_channel->scan_index = index;
> +
> + }
> +
> + channels += num_local_channels;
> + }
> +
> + return 0;
> +}
> +
> +static void ad74413r_regulator_disable(void *regulator)
> +{
> + regulator_disable(regulator);
> +}
> +
> +static int ad74413r_probe(struct spi_device *spi)
> +{
> + struct ad74413r_state *st;
> + struct iio_dev *indio_dev;
> + unsigned int sillicon_rev_id;
> + const char *name;
> + int ret;
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> + if (indio_dev == NULL)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + spi_set_drvdata(spi, st);
> +
> + st->spi = spi;
> + st->dev = &spi->dev;
> + st->config = of_device_get_match_data(&spi->dev);
> + st->indio_dev = indio_dev;
That is almost always a sign of a design issue. You should always
be navigating in one direction, not both. Normally seeing this implies
we have callbacks taking the wrong data structure for the model we are
using for IIO drivers.
> + mutex_init(&st->lock);
> + init_completion(&st->adc_data_completion);
> +
> + name = dev_name(st->dev);
> +
> + st->regmap = devm_regmap_init(st->dev, NULL, &spi->dev, &ad74413r_regmap_config);
> + if (IS_ERR(st->regmap)) {
> + ret = PTR_ERR(st->regmap);
> + dev_err(st->dev, "Failed to create regmap: %d\n", ret);
> + return ret;
> + }
> +
> + ret = regmap_read(st->regmap, AD74413R_REG_SILLICON_REV, &sillicon_rev_id);
> + if (ret) {
> + dev_err(st->dev, "Failed to read sillicon rev: %d\n", ret);
> + return ret;
> + }
> +
> + sillicon_rev_id = FIELD_GET(AD74413R_SILLICON_REV_ID_MASK, sillicon_rev_id);
> + if (sillicon_rev_id != AD74413R_SILLICON_REV_ID_EXPECTED) {
> + dev_err(st->dev, "Read sillicon rev id %d does not match expected rev id %d\n",
> + sillicon_rev_id, AD74413R_SILLICON_REV_ID_EXPECTED);
Not supporting future silicon revs is unusual...
> + return -EINVAL;
> + }
> +
> + st->refin_reg = devm_regulator_get(st->dev, "refin");
> + if (IS_ERR(st->refin_reg)) {
> + dev_err(st->dev, "Failed to get refin regulator: %d\n", ret);
return dev_err_probe() as it might be deferred and we both want to only print in real error
cases + stash the information needed to debug deferred probe issues.
> + return PTR_ERR(st->refin_reg);
> + }
> +
> + ret = regulator_enable(st->refin_reg);
> + if (ret) {
> + dev_err(st->dev, "Failed to enable refin regulator: %d\n", ret);
> + return ret;
> + }
> +
> + ret = devm_add_action_or_reset(st->dev, ad74413r_regulator_disable,
> + st->refin_reg);
> + if (ret) {
> + dev_err(st->dev, "Failed to add refin regulator disable action: %d\n", ret);
Some error paths are incredibly unlikely to happen, so I would look at whether you can
reduce the debug prints in path such as this one.
> + return ret;
> + }
> +
> + ret = of_property_read_u32(st->dev->of_node, "adi,rsense-resistance-ohms",
> + &st->rsense_resistance_ohms);
As mentioned above, device_property_read_u32()..
> + if (ret) {
> + dev_err(st->dev, "Failed to get rsense resistance: %d\n", ret);
> + return ret;
> + }
> +
> + st->gpiochip.label = name;
> + st->gpiochip.base = -1;
> + st->gpiochip.ngpio = AD74413R_CHANNEL_MAX;
> + st->gpiochip.parent = st->dev;
> + st->gpiochip.can_sleep = true;
> + st->gpiochip.set = ad74413r_gpio_set;
> + st->gpiochip.set_multiple = ad74413r_gpio_set_multiple;
> + st->gpiochip.owner = THIS_MODULE;
> + st->gpiochip.get = ad74413r_gpio_get;
> +
> + ret = devm_gpiochip_add_data(st->dev, &st->gpiochip, st);
> + if (ret) {
> + dev_err(st->dev, "Failed to add gpio chip: %d\n", ret);
> + return ret;
> + }
> +
> + st->trig = devm_iio_trigger_alloc(st->dev, "%s-dev%d", name, indio_dev->id);
> + if (!st->trig)
> + return -ENOMEM;
> +
> + st->trig->ops = &ad74413r_trigger_ops;
> + st->trig->dev.parent = st->dev;
> + iio_trigger_set_drvdata(st->trig, st);
> +
> + ret = devm_iio_trigger_register(st->dev, st->trig);
> + if (ret)
> + return ret;
> +
> + indio_dev->dev.parent = st->dev;
Set by the IIO core for you by default.
> + indio_dev->name = name;
For IIO this need to be the part number. I'm not sure that's the case currently.
> + indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
> + indio_dev->info = &ad74413r_info;
> + indio_dev->trig = iio_trigger_get(st->trig);
> +
> + ret = ad74413r_parse_channel_configs(st);
> + if (ret)
> + return ret;
> +
> + ret = ad74413r_count_iio_channels(st);
> + if (ret)
> + return ret;
> +
> + ret = ad74413r_setup_iio_channels(st);
> + if (ret) {
> + dev_err(st->dev, "Failed to setup iio channels: %d\n", ret);
> + return ret;
> + }
> +
> + ret = ad74413r_set_adc_conv_seq(st, AD74413R_CONV_SEQ_OFF);
> + if (ret)
> + return ret;
> +
> + ret = devm_request_irq(st->dev, spi->irq, ad74413r_adc_data_interrupt,
> + IRQF_TRIGGER_FALLING, name, st);
> + if (ret) {
> + dev_err(st->dev, "Failed to request threaded irq: %d\n", ret);
> + return ret;
> + }
> +
> + ret = devm_iio_triggered_buffer_setup(st->dev, indio_dev, &iio_pollfunc_store_time,
> + &ad74413r_trigger_handler, &ad74413r_buffer_ops);
> + if (ret) {
> + dev_err(st->dev, "Failed to setup triggered buffer: %d\n", ret);
> + return ret;
> + }
> +
> + return devm_iio_device_register(st->dev, indio_dev);
> +}
> +
> +static int ad74413r_unregister_driver(struct spi_driver *spi)
> +{
> + spi_unregister_driver(spi);
> +
> + return 0;
> +}
> +
> +static int __init ad74413r_register_driver(struct spi_driver *spi)
> +{
> + crc8_populate_msb(ad74413r_crc8_table, AD74413R_CRC_POLYNOMIAL);
> +
> + return spi_register_driver(spi);
> +}
> +
> +static const struct ad74413r_config ad74412r_config_data = {
> + .hart_support = false,
> +};
> +
> +static const struct ad74413r_config ad74413r_config_data = {
> + .hart_support = true,
> +};
> +
> +static const struct of_device_id ad74413r_dt_id[] = {
> + {
> + .compatible = "adi,ad74412r",
> + .data = &ad74412r_config_data,
> + },
> + {
> + .compatible = "adi,ad74413r",
> + .data = &ad74413r_config_data,
> + },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, ad74413r_dt_id);
> +
> +static struct spi_driver ad74413r_driver = {
> + .driver = {
> + .name = "ad74413r",
> + .of_match_table = ad74413r_dt_id,
> + },
> + .probe = ad74413r_probe,
> +};
> +
> +module_driver(ad74413r_driver, ad74413r_register_driver, ad74413r_unregister_driver);
> +
> +MODULE_AUTHOR("Cosmin Tanislav <cosmin.tanislav@...log.com>");
> +MODULE_DESCRIPTION("Analog Devices AD74413R ADDAC");
> +MODULE_LICENSE("GPL v2");
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