Re: [PATCH 2/2] iio: adc: ad717x: add AD717X driver
From: Nuno Sá
Date: Thu Aug 10 2023 - 07:57:13 EST
Hi Dumitru,
Thanks for taking care of this driver which is out of tree for a long time... Some
comments below.
On Thu, 2023-08-10 at 12:33 +0300, Dumitru Ceclan wrote:
> The AD717x family offer a complete integrated Sigma-Delta ADC solution
> which can be used in high precision, low noise single channel
> applications or higher speed multiplexed applications. The Sigma-Delta
> ADC is intended primarily for measurement of signals close to DC but also
> delivers outstanding performance with input bandwidths out to ~10kHz.
>
> Signed-off-by: Dumitru Ceclan <mitrutzceclan@xxxxxxxxx>
> ---
> drivers/iio/adc/Kconfig | 7 +
> drivers/iio/adc/Makefile | 1 +
> drivers/iio/adc/ad717x.c | 999 +++++++++++++++++++++++++++++++++++++++
> 3 files changed, 1007 insertions(+)
> create mode 100644 drivers/iio/adc/ad717x.c
>
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index dc14bde31ac1..294a48b05769 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -54,6 +54,13 @@ config AD7124
> To compile this driver as a module, choose M here: the module will be
> called ad7124.
>
> +config AD717X
> + tristate "Analog Devices AD717x driver"
> + depends on SPI_MASTER
> + select AD_SIGMA_DELTA
> + help
> + Say yes here to build support for Analog Devices AD717x ADC.
> +
> config AD7192
> tristate "Analog Devices AD7190 AD7192 AD7193 AD7195 ADC driver"
> depends on SPI
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index eb6e891790fb..e9491e4eff8d 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -9,6 +9,7 @@ obj-$(CONFIG_AD_SIGMA_DELTA) += ad_sigma_delta.o
> obj-$(CONFIG_AD4130) += ad4130.o
> obj-$(CONFIG_AD7091R5) += ad7091r5.o ad7091r-base.o
> obj-$(CONFIG_AD7124) += ad7124.o
> +obj-$(CONFIG_AD717X) += ad717x.o
> obj-$(CONFIG_AD7192) += ad7192.o
> obj-$(CONFIG_AD7266) += ad7266.o
> obj-$(CONFIG_AD7280) += ad7280a.o
> diff --git a/drivers/iio/adc/ad717x.c b/drivers/iio/adc/ad717x.c
> new file mode 100644
> index 000000000000..d14a3e0e2d93
> --- /dev/null
> +++ b/drivers/iio/adc/ad717x.c
> @@ -0,0 +1,999 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * AD7172-2/AD7173-8/AD7175-2/AD7176-2 SPI ADC driver
> + * Copyright (C) 2023 Analog Devices, Inc.
> + */
> +
> +#include <linux/bitfield.h>
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/sched.h>
> +#include <linux/slab.h>
> +#include <linux/spi/spi.h>
> +#include <linux/sysfs.h>
> +#include <linux/units.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/buffer.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/iio/adc/ad_sigma_delta.h>
> +
> +#define AD717X_REG_COMMS 0x00
> +#define AD717X_REG_ADC_MODE 0x01
> +#define AD717X_REG_INTERFACE_MODE 0x02
> +#define AD717X_REG_CRC 0x03
> +#define AD717X_REG_DATA 0x04
> +#define AD717X_REG_GPIO 0x06
> +#define AD717X_REG_ID 0x07
> +#define AD717X_REG_CH(x) (0x10 + (x))
> +#define AD717X_REG_SETUP(x) (0x20 + (x))
> +#define AD717X_REG_FILTER(x) (0x28 + (x))
> +#define AD717X_REG_OFFSET(x) (0x30 + (x))
> +#define AD717X_REG_GAIN(x) (0x38 + (x))
> +
> +#define AD717X_CH_ENABLE BIT(15)
> +#define AD717X_CH_SETUP_SEL(x) ((x) << 12)
> +#define AD717X_CH_SETUP_AINPOS(x) ((x) << 5)
> +#define AD717X_CH_SETUP_AINNEG(x) (x)
> +
> +#define AD717X_CH_ADDRESS(pos, neg) \
> + (AD717X_CH_SETUP_AINPOS(pos) | AD717X_CH_SETUP_AINNEG(neg))
> +
> +#define AD7172_ID 0x00d0
> +#define AD7173_ID 0x30d0
> +#define AD7175_ID 0x0cd0
> +#define AD7176_ID 0x0c90
> +#define AD717X_ID_MASK 0xfff0
> +
> +#define AD717X_ADC_MODE_REF_EN BIT(15)
> +#define AD717X_ADC_MODE_SING_CYC BIT(13)
> +#define AD717X_ADC_MODE_MODE_MASK 0x70
> +#define AD717X_ADC_MODE_MODE(x) ((x) << 4)
> +#define AD717X_ADC_MODE_CLOCKSEL_MASK 0xc
> +#define AD717X_ADC_MODE_CLOCKSEL(x) ((x) << 2)
> +
> +#define AD717X_GPIO_PDSW BIT(14)
> +#define AD717X_GPIO_OP_EN2_3 BIT(13)
> +#define AD717X_GPIO_MUX_IO BIT(12)
> +#define AD717X_GPIO_SYNC_EN BIT(11)
> +#define AD717X_GPIO_ERR_EN BIT(10)
> +#define AD717X_GPIO_ERR_DAT BIT(9)
> +#define AD717X_GPIO_GP_DATA3 BIT(7)
> +#define AD717X_GPIO_GP_DATA2 BIT(6)
> +#define AD717X_GPIO_IP_EN1 BIT(5)
> +#define AD717X_GPIO_IP_EN0 BIT(4)
> +#define AD717X_GPIO_OP_EN1 BIT(3)
> +#define AD717X_GPIO_OP_EN0 BIT(2)
> +#define AD717X_GPIO_GP_DATA1 BIT(1)
> +#define AD717X_GPIO_GP_DATA0 BIT(0)
> +
> +#define AD717X_INTERFACE_DATA_STAT BIT(6)
> +#define AD717X_INTERFACE_DATA_STAT_EN(x)\
> + FIELD_PREP(AD717X_INTERFACE_DATA_STAT, x)
> +
> +#define AD717X_SETUP_BIPOLAR BIT(12)
> +#define AD717X_SETUP_AREF_BUF (0x3 << 10)
> +#define AD717X_SETUP_AIN_BUF (0x3 << 8)
> +#define AD717X_SETUP_REF_SEL_MASK 0x30
> +#define AD717X_SETUP_REF_SEL_AVDD1_AVSS 0x30
> +#define AD717X_SETUP_REF_SEL_INT_REF 0x20
> +#define AD717X_SETUP_REF_SEL_EXT_REF2 0x10
> +#define AD717X_SETUP_REF_SEL_EXT_REF 0x00
> +
> +#define AD717X_FILTER_ODR0_MASK 0x1f
> +#define AD717X_MAX_CONFIGS 8
> +
> +enum ad717x_ids {
> + ID_AD7172_2,
> + ID_AD7173_8,
> + ID_AD7175_2,
> + ID_AD7176_2,
> +};
> +
> +struct ad717x_device_info {
> + unsigned int id;
> + unsigned int num_inputs;
> + unsigned int num_channels;
> + unsigned int num_configs;
> + bool has_gp23;
> + bool has_temp;
> + unsigned int clock;
> +
> + const unsigned int *sinc5_data_rates;
> + unsigned int num_sinc5_data_rates;
> +};
> +
> +struct ad717x_channel_config {
> + bool live;
> + unsigned char cfg_slot;
> + /* Fields from this point are used to compare equality of configs */
> + unsigned char odr;
> + bool bipolar;
> + bool input_buf;
> +};
> +
> +struct ad717x_channel {
> + unsigned int chan_reg;
> + struct ad717x_channel_config cfg;
> + unsigned int ain;
> +};
> +
> +struct ad717x_state {
> + const struct ad717x_device_info *info;
> + struct ad_sigma_delta sd;
> + struct ad717x_channel *channels;
> + struct regulator *reg;
> + unsigned int adc_mode;
> + unsigned int interface_mode;
> + unsigned int num_channels;
> + struct mutex cfgs_lock; /* lock for configs access */
> + unsigned long cfg_slots_status; /* slots usage status bitmap*/
> + unsigned long long config_usage_counter;
> + unsigned long long *config_cnts;
> +
> +#ifdef CONFIG_GPIOLIB
> + struct gpio_chip gpiochip;
> + unsigned int gpio_reg;
> + unsigned int gpio_23_mask;
> +#endif
> +};
> +
> +static const unsigned int ad7173_sinc5_data_rates[] = {
> + 6211000, 6211000, 6211000, 6211000, 6211000, 6211000, 5181000, 4444000,
> + 3115000, 2597000, 1007000, 503800, 381000, 200300, 100500, 59520,
> + 49680, 20010, 16333, 10000, 5000, 2500, 1250,
> +};
> +
> +static const unsigned int ad7175_sinc5_data_rates[] = {
> + 50000000, 41667000, 31250000, 27778000, 20833000, 17857000, 12500000,
> + 10000000, 5000000, 2500000, 1000000, 500000, 397500, 200000,
> + 100000, 59920, 49960, 20000, 16666, 10000, 5000,
> +};
> +
> +static const struct ad717x_device_info ad717x_device_info[] = {
> + [ID_AD7172_2] = {
> + .id = AD7172_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .has_gp23 = false,
> + .has_temp = true,
> + .clock = 2000000,
> + .sinc5_data_rates = ad7173_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
> + },
> + [ID_AD7173_8] = {
> + .id = AD7173_ID,
> + .num_inputs = 17,
> + .num_channels = 16,
> + .num_configs = 8,
> + .has_gp23 = true,
> + .has_temp = true,
> + .clock = 2000000,
> + .sinc5_data_rates = ad7173_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7173_sinc5_data_rates),
> + },
> + [ID_AD7175_2] = {
> + .id = AD7175_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .has_gp23 = false,
> + .has_temp = true,
> + .clock = 16000000,
> + .sinc5_data_rates = ad7175_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
> + },
> + [ID_AD7176_2] = {
> + .id = AD7176_ID,
> + .num_inputs = 5,
> + .num_channels = 4,
> + .num_configs = 4,
> + .has_gp23 = false,
> + .has_temp = false,
> + .clock = 16000000,
> + .sinc5_data_rates = ad7175_sinc5_data_rates,
> + .num_sinc5_data_rates = ARRAY_SIZE(ad7175_sinc5_data_rates),
> + },
> +};
> +
> +#ifdef CONFIG_GPIOLIB
> +
> +static struct ad717x_state *gpiochip_to_ad717x(struct gpio_chip *chip)
> +{
> + return container_of(chip, struct ad717x_state, gpiochip);
> +}
> +
> +static int ad717x_gpio_get(struct gpio_chip *chip, unsigned offset)
> +{
> + struct ad717x_state *st = gpiochip_to_ad717x(chip);
> + unsigned int mask;
> + unsigned int value;
> + int ret;
> +
> + switch (offset) {
> + case 0:
> + mask = AD717X_GPIO_GP_DATA0;
> + break;
> + case 1:
> + mask = AD717X_GPIO_GP_DATA1;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + ret = ad_sd_read_reg(&st->sd, AD717X_REG_GPIO, 2, &value);
> + if (ret)
> + return ret;
> +
> + return (bool)(value & mask);
> +}
> +
> +static int ad717x_gpio_update(struct ad717x_state *st, unsigned int set_mask,
> + unsigned int clr_mask)
> +{
> + st->gpio_reg |= set_mask;
> + st->gpio_reg &= ~clr_mask;
> +
> + return ad_sd_write_reg(&st->sd, AD717X_REG_GPIO, 2, st->gpio_reg);
> +}
> +
> +static void ad717x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> +{
> + struct ad717x_state *st = gpiochip_to_ad717x(chip);
> + unsigned int mask, set_mask, clr_mask;
> +
> + switch (offset) {
> + case 0:
> + mask = AD717X_GPIO_GP_DATA0;
> + break;
> + case 1:
> + mask = AD717X_GPIO_GP_DATA1;
> + break;
> + case 2:
> + mask = AD717X_GPIO_GP_DATA2;
> + break;
> + case 3:
> + mask = AD717X_GPIO_GP_DATA3;
> + break;
> + default:
> + return;
> + }
> +
> + if (value) {
> + set_mask = mask;
> + clr_mask = 0;
> + } else {
> + set_mask = 0;
> + clr_mask = mask;
> + }
> +
> + ad717x_gpio_update(st, set_mask, clr_mask);
> +}
> +
> +static int ad717x_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
> +{
> + struct ad717x_state *st = gpiochip_to_ad717x(chip);
> + unsigned int mask;
> +
> + switch (offset) {
> + case 0:
> + mask = AD717X_GPIO_IP_EN0;
> + break;
> + case 1:
> + mask = AD717X_GPIO_IP_EN1;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return ad717x_gpio_update(st, mask, 0);
> +}
> +
> +static int ad717x_gpio_direction_output
> + (struct gpio_chip *chip, unsigned offset, int value)
> +{
> + struct ad717x_state *st = gpiochip_to_ad717x(chip);
> + unsigned int set_mask, clr_mask, val_mask;
> +
> + switch (offset) {
> + case 0:
> + set_mask = AD717X_GPIO_OP_EN0;
> + val_mask = AD717X_GPIO_GP_DATA0;
> + break;
> + case 1:
> + set_mask = AD717X_GPIO_OP_EN1;
> + val_mask = AD717X_GPIO_GP_DATA1;
> + break;
> + /* GP2 and GP3 can not be enabled independently */
> + case 2:
> + st->gpio_23_mask |= (1 << 2);
> + set_mask = AD717X_GPIO_OP_EN2_3;
> + val_mask = AD717X_GPIO_GP_DATA2;
> + break;
> + case 3:
> + st->gpio_23_mask |= (1 << 3);
> + set_mask = AD717X_GPIO_OP_EN2_3;
> + val_mask = AD717X_GPIO_GP_DATA3;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (value) {
> + set_mask |= val_mask;
> + clr_mask = 0;
> + } else {
> + clr_mask = val_mask;
> + }
> +
> + return ad717x_gpio_update(st, set_mask, clr_mask);
> +}
> +
> +static void ad717x_gpio_free(struct gpio_chip *chip, unsigned offset)
> +{
> + struct ad717x_state *st = gpiochip_to_ad717x(chip);
> + unsigned int mask;
> +
> + switch (offset) {
> + case 0:
> + mask = AD717X_GPIO_OP_EN0 | AD717X_GPIO_IP_EN0;
> + break;
> + case 1:
> + mask = AD717X_GPIO_OP_EN1 | AD717X_GPIO_IP_EN1;
> + break;
> + case 2:
> + st->gpio_23_mask &= ~(1 << offset);
> + if (st->gpio_23_mask != 0)
> + return;
> + mask = AD717X_GPIO_OP_EN2_3;
> + break;
> + default:
> + return;
> + }
> +
> + ad717x_gpio_update(st, 0, mask);
> +}
> +
> +static int ad717x_gpio_init(struct ad717x_state *st)
> +{
> + st->gpiochip.label = dev_name(&st->sd.spi->dev);
> + st->gpiochip.base = -1;
> + if (st->info->has_gp23)
> + st->gpiochip.ngpio = 4;
> + else
> + st->gpiochip.ngpio = 2;
> + st->gpiochip.parent = &st->sd.spi->dev;
> + st->gpiochip.can_sleep = true;
> + st->gpiochip.direction_input = ad717x_gpio_direction_input;
> + st->gpiochip.direction_output = ad717x_gpio_direction_output;
> + st->gpiochip.get = ad717x_gpio_get;
> + st->gpiochip.set = ad717x_gpio_set;
> + st->gpiochip.free = ad717x_gpio_free;
> + st->gpiochip.owner = THIS_MODULE;
> +
> + return devm_gpiochip_add_data(&st->sd.spi->dev, &st->gpiochip, NULL);
> +}
> +
> +#else
> +
> +static int ad717x_gpio_init(struct ad717x_state *st) { return 0 };
> +static void ad717x_gpio_cleanup(struct ad717x_state *st) {};
Is ad717x_gpio_cleanup() being used anywhere? Moreover I would maybe just get rid of
the #ifdef wrapper and just select GPIOLIB. How often will it be disabled anyways?
Alternatively, you can just wrap ad717x_gpio_init() and only calls it 'if
(IS_ENABLED(CONFIG_GPIOLIB))... Then, the compiler can figure the rest. Of course you
would still have some extra bytes in your struct. Anyways, I just like to avoid this
#ifdefery.
> +
> +#endif
> +
> +static struct ad717x_state *ad_sigma_delta_to_ad717x(struct ad_sigma_delta *sd)
> +{
> + return container_of(sd, struct ad717x_state, sd);
> +}
> +
> +static void ad717x_reset_usage_cnts(struct ad717x_state *st)
> +{
> + int i;
> +
> + for (i = 0; i < st->info->num_configs; i++)
> + (st->config_cnts)[i] = 0;
> +
> + st->config_usage_counter = 0;
> +}
> +
> +static struct ad717x_channel_config *ad717x_find_live_config
> + (struct ad717x_state *st, struct ad717x_channel_config *cfg)
> +{
> + struct ad717x_channel_config *cfg_aux;
> + ptrdiff_t cmp_size, offset;
> + int i;
> +
> + offset = offsetof(struct ad717x_channel_config, cfg_slot) +
> + sizeof(cfg->cfg_slot);
> + cmp_size = sizeof(*cfg) - offset;
> +
> + for (i = 0; i < st->num_channels; i++) {
> + cfg_aux = &st->channels[i].cfg;
> +
> + if (cfg_aux->live && !memcmp(((void *)cfg) + offset,
> + ((void *)cfg_aux) + offset, cmp_size))
> + return cfg_aux;
> + }
> + return NULL;
> +}
> +
> +static int ad717x_free_config_slot_lru(struct ad717x_state *st)
> +{
> + int i, lru_position = 0;
> +
> + for (i = 1; i < st->info->num_configs; i++)
> + if (st->config_cnts[i] < st->config_cnts[lru_position])
> + lru_position = i;
> +
> + for (i = 0; i < st->num_channels; i++)
> + if (st->channels[i].cfg.cfg_slot == lru_position)
> + st->channels[i].cfg.live = false;
> +
> + assign_bit(lru_position, &st->cfg_slots_status, 0);
> + return lru_position;
> +}
> +
> +static int ad717x_load_config(struct ad717x_state *st,
> + struct ad717x_channel_config *cfg)
> +{
> + unsigned int config;
> + int free_cfg_slot, ret;
> +
> + free_cfg_slot = find_first_zero_bit(&st->cfg_slots_status,
> + st->info->num_configs);
> + if (free_cfg_slot == st->info->num_configs)
> + free_cfg_slot = ad717x_free_config_slot_lru(st);
> +
> + assign_bit(free_cfg_slot, &st->cfg_slots_status, 1);
> + cfg->cfg_slot = free_cfg_slot;
> +
> + config = AD717X_SETUP_REF_SEL_INT_REF;
> +
> + if (cfg->bipolar)
> + config |= AD717X_SETUP_BIPOLAR;
> +
> + if (cfg->input_buf)
> + config |= AD717X_SETUP_AIN_BUF;
> +
> + ret = ad_sd_write_reg(&st->sd, AD717X_REG_SETUP(free_cfg_slot), 2, config);
> + if (ret)
> + return ret;
> +
> + config = AD717X_FILTER_ODR0_MASK & cfg->odr;
> + return ad_sd_write_reg(&st->sd, AD717X_REG_FILTER(free_cfg_slot), 2,
> config);
> +}
> +
> +static int ad717x_config_channel(struct ad717x_state *st, int addr)
> +{
> + struct ad717x_channel_config *cfg = &st->channels[addr].cfg;
> + struct ad717x_channel_config *live_cfg;
> + int ret = 0;
> +
> + if (!cfg->live) {
> + live_cfg = ad717x_find_live_config(st, cfg);
> + if (!live_cfg) {
> + ret = ad717x_load_config(st, cfg);
> + if (ret < 0)
> + return ret;
> + } else {
> + cfg->cfg_slot = live_cfg->cfg_slot;
> + }
> + }
> +
> + cfg->live = true;
> + if (st->config_usage_counter == U64_MAX)
> + ad717x_reset_usage_cnts(st);
> +
> + st->config_usage_counter++;
> + st->config_cnts[cfg->cfg_slot] = st->config_usage_counter;
> +
> + return 0;
> +}
I guess you based yourself in the ad7124 driver for the above? Might be worthy look
at it more carefully to see if there's any nice way to push into the lib so code can
be shared (just some thoughts for future work if that sparks any interest :)).
> +
> +static int ad717x_set_channel(struct ad_sigma_delta *sd, unsigned int channel)
> +{
> + struct ad717x_state *st = ad_sigma_delta_to_ad717x(sd);
> + unsigned int val;
> + int ret;
> +
> + ret = ad717x_config_channel(st, channel);
> + if (ret < 0)
> + return ret;
> +
> + val = AD717X_CH_ENABLE |
> + AD717X_CH_SETUP_SEL(st->channels[channel].cfg.cfg_slot) |
> + st->channels[channel].ain;
> +
> + return ad_sd_write_reg(&st->sd, AD717X_REG_CH(channel), 2, val);
> +}
> +
> +static int ad717x_set_mode(struct ad_sigma_delta *sd,
> + enum ad_sigma_delta_mode mode)
> +{
> + struct ad717x_state *st = ad_sigma_delta_to_ad717x(sd);
> +
> + st->adc_mode &= ~AD717X_ADC_MODE_MODE_MASK;
> + st->adc_mode |= AD717X_ADC_MODE_MODE(mode);
> +
> + return ad_sd_write_reg(&st->sd, AD717X_REG_ADC_MODE, 2, st->adc_mode);
> +}
> +
> +static int ad717x_append_status(struct ad_sigma_delta *sd, bool append)
> +{
> + struct ad717x_state *st = container_of(sd, struct ad717x_state, sd);
> + unsigned int interface_mode = st->interface_mode;
> + int ret;
> +
> + interface_mode |= AD717X_INTERFACE_DATA_STAT_EN(append);
> + ret = ad_sd_write_reg(&st->sd, AD717X_REG_INTERFACE_MODE, 2,
> interface_mode);
> + if (ret < 0)
> + return ret;
> +
> + st->interface_mode = interface_mode;
> +
> + return 0;
> +}
> +
> +static int ad717x_disable_all(struct ad_sigma_delta *sd)
> +{
> + struct ad717x_state *st = container_of(sd, struct ad717x_state, sd);
> + int ret;
> + int i;
> +
> + for (i = 0; i < st->num_channels; i++) {
> + ret = ad_sd_write_reg(sd, AD717X_REG_CH(i), 2, 0);
> + if (ret < 0)
> + return ret;
> + }
> +
> + return 0;
> +}
> +
> +static struct ad_sigma_delta_info ad717x_sigma_delta_info = {
> + .set_channel = ad717x_set_channel,
> + .append_status = ad717x_append_status,
> + .disable_all = ad717x_disable_all,
> + .set_mode = ad717x_set_mode,
> + .has_registers = true,
> + .addr_shift = 0,
> + .read_mask = BIT(6),
> + .status_ch_mask = GENMASK(3, 0),
> + .data_reg = AD717X_REG_DATA,
> + .irq_flags = IRQF_TRIGGER_FALLING
> +};
> +
> +static int ad717x_setup(struct iio_dev *indio_dev)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + unsigned int id;
> + u8 *buf;
> + int ret;
> +
> + /* reset the serial interface */
> + buf = kcalloc(8, sizeof(*buf), GFP_KERNEL);
> + if (!buf)
> + return -ENOMEM;
> +
> + memset(buf, 0xff, 8);
> + ret = spi_write(st->sd.spi, buf, 8);
> + kfree(buf);
Hmm, why allocating the buffer? I guess one could argue that we'll get DMA safe
alignment but then maybe use some define instead of the magic 8.
> + if (ret < 0)
> + return ret;
> +
> + /* datasheet recommends a delay of at least 500us after reset */
> + usleep_range(500, 1000);
> +
> + ret = ad_sd_read_reg(&st->sd, AD717X_REG_ID, 2, &id);
> + if (ret)
> + return ret;
> +
> + id &= AD717X_ID_MASK;
> + if (id != st->info->id)
> + dev_warn(&st->sd.spi->dev, "Unexpected device id: %x, expected:
> %x\n",
> + id, st->info->id);
> +
Shouldn't we error out?
> + mutex_init(&st->cfgs_lock);
> + st->adc_mode |= AD717X_ADC_MODE_REF_EN | AD717X_ADC_MODE_SING_CYC;
> + st->interface_mode = 0x0;
> +
> + st->config_usage_counter = 0;
> + st->config_cnts = devm_kzalloc(&indio_dev->dev,
> + st->info->num_configs * sizeof(u64),
> + GFP_KERNEL);
> + if (!st->config_cnts)
> + return -ENOMEM;
> +
> + /* All channels are enabled by default after a reset */
> + ret = ad717x_disable_all(&st->sd);
> + if (ret < 0)
> + return ret;
> +
Just return ad717x_disable_all();
> + return 0;
> +}
> +
> +static int ad717x_read_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int *val, int *val2, long info)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + unsigned int reg;
> + int ret;
> +
> + switch (info) {
> + case IIO_CHAN_INFO_RAW:
> + ret = ad_sigma_delta_single_conversion(indio_dev, chan, val);
> + if (ret < 0)
> + return ret;
> +
> + /* disable channel after single conversion */
> + ret = ad_sd_write_reg(&st->sd, AD717X_REG_CH(chan->address), 2,
> + 0);
Hmm, since you're here... I think we should bring this into the sigma delta lib. So,
when sequencer is supported, the device samples all enabled channels one by one so I
get why you're doing this for a single conversion. However, note that
ad_sigma_delta_single_conversion() is already taking care of calling a callback so
the channel can be prepared and enabled for the conversion. So, it's only natural to
disable that channel inside ad_sigma_delta_single_conversion(). We already have a
.disable_all() option so adding one only with .disable() would make sense. Or an
extra parameter in .set_channel() callback but that would be more work and Im not
sure if it brings any benefit.
If you take care of the above, another thing to remember is to update the ad7124.c
driver which is doing the same thing.
> + if (ret < 0)
> + return ret;
> +
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SCALE:
> + if (chan->type == IIO_TEMP) {
> + *val = 250000000;
> + *val2 = 800273203; /* (2**24 * 477) / 10 */
> + return IIO_VAL_FRACTIONAL;
> + } else {
> + *val = 2500;
> + if (chan->differential)
> + *val2 = 23;
> + else
> + *val2 = 24;
> + return IIO_VAL_FRACTIONAL_LOG2;
> + }
> + case IIO_CHAN_INFO_OFFSET:
> + if (chan->type == IIO_TEMP) {
> + *val = -874379;
> + } else {
> + if (chan->differential)
> + *val = -(1 << (chan->scan_type.realbits - 1));
nit: I don't expect the driver to really be updated with more devices (it's like this
for a long time) but the above is not very extensible... Imagine we add a device with
32bit channels? We would enter shady waters If I'm not missing anything.
> + else
> + *val = 0;
> + }
> + return IIO_VAL_INT;
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + reg = st->channels[chan->address].cfg.odr;
> +
> + *val = st->info->sinc5_data_rates[reg] / MILLI;
> + *val2 = (st->info->sinc5_data_rates[reg] % MILLI) * MILLI;
> +
> + return IIO_VAL_INT_PLUS_MICRO;
> + }
> + return -EINVAL;
> +}
> +
> +static int ad717x_write_raw(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, int val, int val2, long info)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + struct ad717x_channel_config *cfg;
> + unsigned int freq, i, reg;
> + int ret = 0;
> +
> + mutex_lock(&st->cfgs_lock);
> + if (iio_buffer_enabled(indio_dev)) {
> + mutex_unlock(&st->cfgs_lock);
> + return -EBUSY;
> + }
> +
iio_device_claim_direct_mode()
> + switch (info) {
> + case IIO_CHAN_INFO_SAMP_FREQ:
> + freq = val * MILLI + val2 / MILLI;
> +
> + for (i = 0; i < st->info->num_sinc5_data_rates - 1; i++) {
> + if (freq >= st->info->sinc5_data_rates[i])
> + break;
> + }
> +
> + cfg = &st->channels[chan->address].cfg;
> + cfg->odr = i;
> +
> + if (cfg->live) {
> + ret = ad_sd_read_reg(&st->sd, AD717X_REG_FILTER(cfg-
> >cfg_slot), 2, ®);
> + if (ret)
> + break;
> + reg &= ~AD717X_FILTER_ODR0_MASK;
> + reg |= i;
> + ret = ad_sd_write_reg(&st->sd, AD717X_REG_FILTER(cfg-
> >cfg_slot), 2, reg);
> + }
> + break;
> + default:
> + ret = -EINVAL;
> + break;
> + }
> +
> + mutex_unlock(&st->cfgs_lock);
> + return ret;
> +}
> +
> +static int ad717x_write_raw_get_fmt(struct iio_dev *indio_dev,
> + struct iio_chan_spec const *chan, long mask)
> +{
> + return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int ad717x_update_scan_mode(struct iio_dev *indio_dev,
> + const unsigned long *scan_mask)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + bool bit_set;
> + int ret;
> + int i;
> +
> + mutex_lock(&st->cfgs_lock);
> + for (i = 0; i < st->num_channels; i++) {
> + bit_set = test_bit(i, scan_mask);
> + if (bit_set)
why not test_bit() directly?
> + ret = ad717x_set_channel(&st->sd, i);
> + else
> + ret = ad_sd_write_reg(&st->sd, AD717X_REG_CH(i), 2, 0);
> +
> + if (ret < 0) {
> + mutex_unlock(&st->cfgs_lock);
> + return ret;
> + }
> + }
> +
> + mutex_unlock(&st->cfgs_lock);
> +
> + return 0;
> +}
> +
> +static int ad717x_debug(struct iio_dev *indio_dev, unsigned int reg,
> + unsigned int writeval, unsigned int *readval)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + u8 reg_size = 2;
> +
> + if (reg == 0)
> + reg_size = 1;
> + else if (reg == AD717X_REG_CRC || reg == AD717X_REG_DATA ||
> + reg >= AD717X_REG_OFFSET(0))
> + reg_size = 3;
> +
> + if (readval)
> + return ad_sd_read_reg(&st->sd, reg, reg_size, readval);
> +
> + return ad_sd_write_reg(&st->sd, reg, reg_size, writeval);
> +}
> +
> +static const struct iio_info ad717x_info = {
> + .read_raw = &ad717x_read_raw,
> + .write_raw = &ad717x_write_raw,
> + .write_raw_get_fmt = &ad717x_write_raw_get_fmt,
> + .debugfs_reg_access = &ad717x_debug,
> + .validate_trigger = ad_sd_validate_trigger,
> + .update_scan_mode = ad717x_update_scan_mode,
> +};
> +
> +static const struct iio_chan_spec ad717x_channel_template = {
> + .type = IIO_VOLTAGE,
> + .indexed = 1,
> + .channel = 0,
> + .address = AD717X_CH_ADDRESS(0, 0),
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE),
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 24,
> + .storagebits = 32,
> + .shift = 0,
> + .endianness = IIO_BE,
> + },
> +};
> +
> +static const struct iio_chan_spec ad717x_temp_iio_channel_template = {
> + .type = IIO_TEMP,
> + .indexed = 1,
> + .channel = 17,
> + .channel2 = 18,
> + .address = 0,
> + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> + BIT(IIO_CHAN_INFO_SCALE) | BIT(IIO_CHAN_INFO_OFFSET),
> + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
> + .scan_index = 0,
> + .scan_type = {
> + .sign = 'u',
> + .realbits = 24,
> + .storagebits = 32,
> + .shift = 0,
> + .endianness = IIO_BE,
> + },
> +};
> +
> +static int ad717x_of_parse_channel_config(struct iio_dev *indio_dev)
> +{
> + struct ad717x_state *st = iio_priv(indio_dev);
> + struct ad717x_channel *channels_st_priv;
> + struct fwnode_handle *child;
> + struct device *dev = indio_dev->dev.parent;
> + struct iio_chan_spec *chan;
> + unsigned int num_channels = 0;
> + unsigned int ain[2], chan_index = 0;
> + bool use_temp = false;
> + int ret;
> +
> + num_channels = device_get_child_node_count(dev);
> +
> + if (device_property_read_bool(dev, "adi,temp-channel")) {
> + if (!st->info->has_temp) {
> + dev_err(indio_dev->dev.parent,
> + "Current chip does not support temperature
> channel");
> + return -EINVAL;
> + }
> +
> + num_channels++;
> + use_temp = true;
> + }
> +
> + st->num_channels = num_channels;
> +
> + if (num_channels == 0)
> + return 0;
> +
> + chan = devm_kcalloc(indio_dev->dev.parent, sizeof(*chan), num_channels,
> + GFP_KERNEL);
> + if (!chan)
> + return -ENOMEM;
> +
> + channels_st_priv = devm_kcalloc(indio_dev->dev.parent, num_channels,
> + sizeof(*channels_st_priv), GFP_KERNEL);
> + if (!channels_st_priv)
> + return -ENOMEM;
> +
> + indio_dev->channels = chan;
> + indio_dev->num_channels = num_channels;
> + st->channels = channels_st_priv;
> +
> + if (use_temp) {
> + chan[chan_index] = ad717x_temp_iio_channel_template;
> + channels_st_priv[chan_index].ain =
> + AD717X_CH_ADDRESS(chan[chan_index].channel,
> chan[chan_index].channel2);
> + channels_st_priv[chan_index].cfg.bipolar = false;
> + channels_st_priv[chan_index].cfg.input_buf = true;
> + chan_index++;
> + }
> +
> + device_for_each_child_node(dev, child) {
> + ret = fwnode_property_read_u32_array(child, "diff-channels", ain,
> 2);
> + if (ret) {
> + fwnode_handle_put(child);
> + return ret;
> + }
> +
> + if (ain[0] >= st->info->num_inputs ||
> + ain[1] >= st->info->num_inputs) {
> + dev_err(indio_dev->dev.parent,
> + "Input pin number out of range for pair (%d %d).",
> ain[0], ain[1]);
dev_err_probe() in all the error paths during probe. Moreover, just use 'dev' as you
are declaring it above.
> + fwnode_handle_put(child);
> + return -EINVAL;
> + }
> +
> + chan[chan_index] = ad717x_channel_template;
> + chan[chan_index].address = chan_index;
> + chan[chan_index].scan_index = chan_index;
> + chan[chan_index].channel = ain[0];
> + chan[chan_index].channel2 = ain[1];
I think 'channel2' only makes sense for differential channels. I assume the core will
discard it if 'differential' is not set but for readability I would set it only below
inside the if block. The 'diff-channels' is also not perfect as we might actually
have a single ended channel defined in it. But maybe that's actually expected...
> +
> + channels_st_priv[chan_index].ain =
> + AD717X_CH_ADDRESS(ain[0], ain[1]);
> + channels_st_priv[chan_index].chan_reg = chan_index;
> + channels_st_priv[chan_index].cfg.input_buf = true;
> + channels_st_priv[chan_index].cfg.odr = 0;
> +
> + chan[chan_index].differential = fwnode_property_read_bool(child,
> "adi,bipolar");
> + if (chan[chan_index].differential) {
> + chan[chan_index].info_mask_separate |=
> BIT(IIO_CHAN_INFO_OFFSET);
> + channels_st_priv[chan_index].cfg.bipolar = true;
> + }
> +
> + chan_index++;
> + }
> +
> + return 0;
> +}
> +
> +static int ad717x_probe(struct spi_device *spi)
> +{
> + struct ad717x_state *st;
> + struct iio_dev *indio_dev;
> + int ret;
> +
> + if (!spi->irq) {
> + dev_err(&spi->dev, "No IRQ specified\n");
> + return -ENODEV;
> + }
Drop the above...
> +
> + indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
> + if (!indio_dev)
> + return -ENOMEM;
> +
> + st = iio_priv(indio_dev);
> + st->info = device_get_match_data(&spi->dev);
> + if (!st->info)
> + return -ENODEV;
> +
spi_get_device_match_data() (not really sure if this is still applicable since some
work related to this is being done for i2c - and eventually in spi I guess).
> + indio_dev->dev.parent = &spi->dev;
drop this...
> + indio_dev->name = spi_get_device_id(spi)->name;
> + indio_dev->modes = INDIO_DIRECT_MODE;
> + indio_dev->info = &ad717x_info;
> +
> + ad717x_sigma_delta_info.num_slots = st->info->num_configs;
> + ret = ad_sd_init(&st->sd, indio_dev, spi, &ad717x_sigma_delta_info);
> + if (ret < 0)
> + return ret;
> +
> + spi_set_drvdata(spi, indio_dev);
> +
> + ret = ad717x_of_parse_channel_config(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_ad_sd_setup_buffer_and_trigger(&spi->dev, indio_dev);
> + if (ret < 0)
> + return ret;
> +
> + ret = ad717x_setup(indio_dev);
> + if (ret)
> + return ret;
> +
> + ret = devm_iio_device_register(&spi->dev, indio_dev);
> + if (ret)
> + return ret;
> +
> + return ad717x_gpio_init(st);
> +}
> +
> +static const struct of_device_id ad717x_of_match[] = {
> + { .compatible = "adi,ad7172-2",
> + .data = &ad717x_device_info[ID_AD7172_2] },
> + { .compatible = "adi,ad7173-8",
> + .data = &ad717x_device_info[ID_AD7173_8] },
> + { .compatible = "adi,ad7175-2",
> + .data = &ad717x_device_info[ID_AD7175_2] },
> + { .compatible = "adi,ad7176-2",
> + .data = &ad717x_device_info[ID_AD7176_2] },
> + {}
> +}
> +MODULE_DEVICE_TABLE(of, ad717x_of_match);
> +
> +static const struct spi_device_id ad717x_id_table[] = {
> + { "ad7172-2", },
> + { "ad7173-8", },
> + { "ad7175-2", },
> + { "ad7176-2", },
> + {}
> +};
> +MODULE_DEVICE_TABLE(spi, ad717x_id_table);
> +
> +static struct spi_driver ad717x_driver = {
> + .driver = {
> + .name = "ad717x",
I would keep the name as we have out of tree which is ad7173.c. I'm not sure if
there's any policy in here but I think typically you just name your driver from the
first supported device and then extend it from there. Since here you are just adding
more than one device at once, it would be nice if you could keep the name of the
driver Lars originally developed...
> + .owner = THIS_MODULE,
No need for the above
> + .of_match_table = of_match_ptr(ad717x_of_match),
Drop of_match_ptr()
- Nuno Sá