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linux-sg2042/drivers/iio/adc/ad7606.c

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// SPDX-License-Identifier: GPL-2.0
/*
* AD7606 SPI ADC driver
*
* Copyright 2011 Analog Devices Inc.
*/
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regulator/consumer.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/util_macros.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include "ad7606.h"
/*
* Scales are computed as 5000/32768 and 10000/32768 respectively,
* so that when applied to the raw values they provide mV values
*/
static const unsigned int ad7606_scale_avail[2] = {
152588, 305176
};
static const unsigned int ad7616_sw_scale_avail[3] = {
76293, 152588, 305176
};
static const unsigned int ad7606_oversampling_avail[7] = {
1, 2, 4, 8, 16, 32, 64,
};
static const unsigned int ad7616_oversampling_avail[8] = {
1, 2, 4, 8, 16, 32, 64, 128,
};
static int ad7606_reset(struct ad7606_state *st)
{
if (st->gpio_reset) {
gpiod_set_value(st->gpio_reset, 1);
ndelay(100); /* t_reset >= 100ns */
gpiod_set_value(st->gpio_reset, 0);
return 0;
}
return -ENODEV;
}
static int ad7606_reg_access(struct iio_dev *indio_dev,
unsigned int reg,
unsigned int writeval,
unsigned int *readval)
{
struct ad7606_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
if (readval) {
ret = st->bops->reg_read(st, reg);
if (ret < 0)
goto err_unlock;
*readval = ret;
ret = 0;
} else {
ret = st->bops->reg_write(st, reg, writeval);
}
err_unlock:
mutex_unlock(&st->lock);
return ret;
}
static int ad7606_read_samples(struct ad7606_state *st)
{
unsigned int num = st->chip_info->num_channels - 1;
u16 *data = st->data;
int ret;
/*
* The frstdata signal is set to high while and after reading the sample
* of the first channel and low for all other channels. This can be used
* to check that the incoming data is correctly aligned. During normal
* operation the data should never become unaligned, but some glitch or
* electrostatic discharge might cause an extra read or clock cycle.
* Monitoring the frstdata signal allows to recover from such failure
* situations.
*/
if (st->gpio_frstdata) {
ret = st->bops->read_block(st->dev, 1, data);
if (ret)
return ret;
if (!gpiod_get_value(st->gpio_frstdata)) {
ad7606_reset(st);
return -EIO;
}
data++;
num--;
}
return st->bops->read_block(st->dev, num, data);
}
static irqreturn_t ad7606_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7606_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&st->lock);
ret = ad7606_read_samples(st);
if (ret == 0)
iio_push_to_buffers_with_timestamp(indio_dev, st->data,
iio_get_time_ns(indio_dev));
iio_trigger_notify_done(indio_dev->trig);
/* The rising edge of the CONVST signal starts a new conversion. */
gpiod_set_value(st->gpio_convst, 1);
mutex_unlock(&st->lock);
return IRQ_HANDLED;
}
static int ad7606_scan_direct(struct iio_dev *indio_dev, unsigned int ch)
{
struct ad7606_state *st = iio_priv(indio_dev);
int ret;
gpiod_set_value(st->gpio_convst, 1);
ret = wait_for_completion_timeout(&st->completion,
msecs_to_jiffies(1000));
if (!ret) {
ret = -ETIMEDOUT;
goto error_ret;
}
ret = ad7606_read_samples(st);
if (ret == 0)
ret = st->data[ch];
error_ret:
gpiod_set_value(st->gpio_convst, 0);
return ret;
}
static int ad7606_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret, ch = 0;
struct ad7606_state *st = iio_priv(indio_dev);
switch (m) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = ad7606_scan_direct(indio_dev, chan->address);
iio_device_release_direct_mode(indio_dev);
if (ret < 0)
return ret;
*val = (short)ret;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (st->sw_mode_en)
ch = chan->address;
*val = 0;
*val2 = st->scale_avail[st->range[ch]];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
*val = st->oversampling;
return IIO_VAL_INT;
}
return -EINVAL;
}
static ssize_t ad7606_show_avail(char *buf, const unsigned int *vals,
unsigned int n, bool micros)
{
size_t len = 0;
int i;
for (i = 0; i < n; i++) {
len += scnprintf(buf + len, PAGE_SIZE - len,
micros ? "0.%06u " : "%u ", vals[i]);
}
buf[len - 1] = '\n';
return len;
}
static ssize_t in_voltage_scale_available_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct ad7606_state *st = iio_priv(indio_dev);
return ad7606_show_avail(buf, st->scale_avail, st->num_scales, true);
}
static IIO_DEVICE_ATTR_RO(in_voltage_scale_available, 0);
static int ad7606_write_scale_hw(struct iio_dev *indio_dev, int ch, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
gpiod_set_value(st->gpio_range, val);
return 0;
}
static int ad7606_write_os_hw(struct iio_dev *indio_dev, int val)
{
struct ad7606_state *st = iio_priv(indio_dev);
DECLARE_BITMAP(values, 3);
values[0] = val;
gpiod_set_array_value(ARRAY_SIZE(values), st->gpio_os->desc,
st->gpio_os->info, values);
/* AD7616 requires a reset to update value */
if (st->chip_info->os_req_reset)
ad7606_reset(st);
return 0;
}
static int ad7606_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad7606_state *st = iio_priv(indio_dev);
int i, ret, ch = 0;
switch (mask) {
case IIO_CHAN_INFO_SCALE:
mutex_lock(&st->lock);
i = find_closest(val2, st->scale_avail, st->num_scales);
if (st->sw_mode_en)
ch = chan->address;
ret = st->write_scale(indio_dev, ch, i);
if (ret < 0) {
mutex_unlock(&st->lock);
return ret;
}
st->range[ch] = i;
mutex_unlock(&st->lock);
return 0;
case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
if (val2)
return -EINVAL;
i = find_closest(val, st->oversampling_avail,
st->num_os_ratios);
mutex_lock(&st->lock);
ret = st->write_os(indio_dev, i);
if (ret < 0) {
mutex_unlock(&st->lock);
return ret;
}
st->oversampling = st->oversampling_avail[i];
mutex_unlock(&st->lock);
return 0;
default:
return -EINVAL;
}
}
static ssize_t ad7606_oversampling_ratio_avail(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct iio_dev *indio_dev = dev_to_iio_dev(dev);
struct ad7606_state *st = iio_priv(indio_dev);
return ad7606_show_avail(buf, st->oversampling_avail,
st->num_os_ratios, false);
}
static IIO_DEVICE_ATTR(oversampling_ratio_available, 0444,
ad7606_oversampling_ratio_avail, NULL, 0);
static struct attribute *ad7606_attributes_os_and_range[] = {
&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
&iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7606_attribute_group_os_and_range = {
.attrs = ad7606_attributes_os_and_range,
};
static struct attribute *ad7606_attributes_os[] = {
&iio_dev_attr_oversampling_ratio_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7606_attribute_group_os = {
.attrs = ad7606_attributes_os,
};
static struct attribute *ad7606_attributes_range[] = {
&iio_dev_attr_in_voltage_scale_available.dev_attr.attr,
NULL,
};
static const struct attribute_group ad7606_attribute_group_range = {
.attrs = ad7606_attributes_range,
};
static const struct iio_chan_spec ad7605_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(4),
AD7605_CHANNEL(0),
AD7605_CHANNEL(1),
AD7605_CHANNEL(2),
AD7605_CHANNEL(3),
};
static const struct iio_chan_spec ad7606_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(8),
AD7606_CHANNEL(0),
AD7606_CHANNEL(1),
AD7606_CHANNEL(2),
AD7606_CHANNEL(3),
AD7606_CHANNEL(4),
AD7606_CHANNEL(5),
AD7606_CHANNEL(6),
AD7606_CHANNEL(7),
};
/*
* The current assumption that this driver makes for AD7616, is that it's
* working in Hardware Mode with Serial, Burst and Sequencer modes activated.
* To activate them, following pins must be pulled high:
* -SER/PAR
* -SEQEN
* And following pins must be pulled low:
* -WR/BURST
* -DB4/SER1W
*/
static const struct iio_chan_spec ad7616_channels[] = {
IIO_CHAN_SOFT_TIMESTAMP(16),
AD7606_CHANNEL(0),
AD7606_CHANNEL(1),
AD7606_CHANNEL(2),
AD7606_CHANNEL(3),
AD7606_CHANNEL(4),
AD7606_CHANNEL(5),
AD7606_CHANNEL(6),
AD7606_CHANNEL(7),
AD7606_CHANNEL(8),
AD7606_CHANNEL(9),
AD7606_CHANNEL(10),
AD7606_CHANNEL(11),
AD7606_CHANNEL(12),
AD7606_CHANNEL(13),
AD7606_CHANNEL(14),
AD7606_CHANNEL(15),
};
static const struct ad7606_chip_info ad7606_chip_info_tbl[] = {
/* More devices added in future */
[ID_AD7605_4] = {
.channels = ad7605_channels,
.num_channels = 5,
},
[ID_AD7606_8] = {
.channels = ad7606_channels,
.num_channels = 9,
.oversampling_avail = ad7606_oversampling_avail,
.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
},
[ID_AD7606_6] = {
.channels = ad7606_channels,
.num_channels = 7,
.oversampling_avail = ad7606_oversampling_avail,
.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
},
[ID_AD7606_4] = {
.channels = ad7606_channels,
.num_channels = 5,
.oversampling_avail = ad7606_oversampling_avail,
.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
},
[ID_AD7606B] = {
.channels = ad7606_channels,
.num_channels = 9,
.oversampling_avail = ad7606_oversampling_avail,
.oversampling_num = ARRAY_SIZE(ad7606_oversampling_avail),
},
[ID_AD7616] = {
.channels = ad7616_channels,
.num_channels = 17,
.oversampling_avail = ad7616_oversampling_avail,
.oversampling_num = ARRAY_SIZE(ad7616_oversampling_avail),
.os_req_reset = true,
.init_delay_ms = 15,
},
};
static int ad7606_request_gpios(struct ad7606_state *st)
{
struct device *dev = st->dev;
st->gpio_convst = devm_gpiod_get(dev, "adi,conversion-start",
GPIOD_OUT_LOW);
if (IS_ERR(st->gpio_convst))
return PTR_ERR(st->gpio_convst);
st->gpio_reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);
if (IS_ERR(st->gpio_reset))
return PTR_ERR(st->gpio_reset);
st->gpio_range = devm_gpiod_get_optional(dev, "adi,range",
GPIOD_OUT_LOW);
if (IS_ERR(st->gpio_range))
return PTR_ERR(st->gpio_range);
st->gpio_standby = devm_gpiod_get_optional(dev, "standby",
GPIOD_OUT_HIGH);
if (IS_ERR(st->gpio_standby))
return PTR_ERR(st->gpio_standby);
st->gpio_frstdata = devm_gpiod_get_optional(dev, "adi,first-data",
GPIOD_IN);
if (IS_ERR(st->gpio_frstdata))
return PTR_ERR(st->gpio_frstdata);
if (!st->chip_info->oversampling_num)
return 0;
st->gpio_os = devm_gpiod_get_array_optional(dev,
"adi,oversampling-ratio",
GPIOD_OUT_LOW);
return PTR_ERR_OR_ZERO(st->gpio_os);
}
/*
* The BUSY signal indicates when conversions are in progress, so when a rising
* edge of CONVST is applied, BUSY goes logic high and transitions low at the
* end of the entire conversion process. The falling edge of the BUSY signal
* triggers this interrupt.
*/
static irqreturn_t ad7606_interrupt(int irq, void *dev_id)
{
struct iio_dev *indio_dev = dev_id;
struct ad7606_state *st = iio_priv(indio_dev);
if (iio_buffer_enabled(indio_dev)) {
gpiod_set_value(st->gpio_convst, 0);
iio_trigger_poll_chained(st->trig);
} else {
complete(&st->completion);
}
return IRQ_HANDLED;
};
static int ad7606_validate_trigger(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
struct ad7606_state *st = iio_priv(indio_dev);
if (st->trig != trig)
return -EINVAL;
return 0;
}
static int ad7606_buffer_postenable(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
gpiod_set_value(st->gpio_convst, 1);
return 0;
}
static int ad7606_buffer_predisable(struct iio_dev *indio_dev)
{
struct ad7606_state *st = iio_priv(indio_dev);
gpiod_set_value(st->gpio_convst, 0);
return 0;
}
static const struct iio_buffer_setup_ops ad7606_buffer_ops = {
.postenable = &ad7606_buffer_postenable,
.predisable = &ad7606_buffer_predisable,
};
static const struct iio_info ad7606_info_no_os_or_range = {
.read_raw = &ad7606_read_raw,
.validate_trigger = &ad7606_validate_trigger,
};
static const struct iio_info ad7606_info_os_and_range = {
.read_raw = &ad7606_read_raw,
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_os_and_range,
.validate_trigger = &ad7606_validate_trigger,
};
static const struct iio_info ad7606_info_os_range_and_debug = {
.read_raw = &ad7606_read_raw,
.write_raw = &ad7606_write_raw,
.debugfs_reg_access = &ad7606_reg_access,
.attrs = &ad7606_attribute_group_os_and_range,
.validate_trigger = &ad7606_validate_trigger,
};
static const struct iio_info ad7606_info_os = {
.read_raw = &ad7606_read_raw,
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_os,
.validate_trigger = &ad7606_validate_trigger,
};
static const struct iio_info ad7606_info_range = {
.read_raw = &ad7606_read_raw,
.write_raw = &ad7606_write_raw,
.attrs = &ad7606_attribute_group_range,
.validate_trigger = &ad7606_validate_trigger,
};
static const struct iio_trigger_ops ad7606_trigger_ops = {
.validate_device = iio_trigger_validate_own_device,
};
static void ad7606_regulator_disable(void *data)
{
struct ad7606_state *st = data;
regulator_disable(st->reg);
}
int ad7606_probe(struct device *dev, int irq, void __iomem *base_address,
const char *name, unsigned int id,
const struct ad7606_bus_ops *bops)
{
struct ad7606_state *st;
int ret;
struct iio_dev *indio_dev;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
dev_set_drvdata(dev, indio_dev);
st->dev = dev;
mutex_init(&st->lock);
st->bops = bops;
st->base_address = base_address;
/* tied to logic low, analog input range is +/- 5V */
st->range[0] = 0;
st->oversampling = 1;
st->scale_avail = ad7606_scale_avail;
st->num_scales = ARRAY_SIZE(ad7606_scale_avail);
st->reg = devm_regulator_get(dev, "avcc");
if (IS_ERR(st->reg))
return PTR_ERR(st->reg);
ret = regulator_enable(st->reg);
if (ret) {
dev_err(dev, "Failed to enable specified AVcc supply\n");
return ret;
}
ret = devm_add_action_or_reset(dev, ad7606_regulator_disable, st);
if (ret)
return ret;
st->chip_info = &ad7606_chip_info_tbl[id];
if (st->chip_info->oversampling_num) {
st->oversampling_avail = st->chip_info->oversampling_avail;
st->num_os_ratios = st->chip_info->oversampling_num;
}
ret = ad7606_request_gpios(st);
if (ret)
return ret;
if (st->gpio_os) {
if (st->gpio_range)
indio_dev->info = &ad7606_info_os_and_range;
else
indio_dev->info = &ad7606_info_os;
} else {
if (st->gpio_range)
indio_dev->info = &ad7606_info_range;
else
indio_dev->info = &ad7606_info_no_os_or_range;
}
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->name = name;
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
init_completion(&st->completion);
ret = ad7606_reset(st);
if (ret)
dev_warn(st->dev, "failed to RESET: no RESET GPIO specified\n");
/* AD7616 requires al least 15ms to reconfigure after a reset */
if (st->chip_info->init_delay_ms) {
if (msleep_interruptible(st->chip_info->init_delay_ms))
return -ERESTARTSYS;
}
st->write_scale = ad7606_write_scale_hw;
st->write_os = ad7606_write_os_hw;
if (st->bops->sw_mode_config)
st->sw_mode_en = device_property_present(st->dev,
"adi,sw-mode");
if (st->sw_mode_en) {
/* Scale of 0.076293 is only available in sw mode */
st->scale_avail = ad7616_sw_scale_avail;
st->num_scales = ARRAY_SIZE(ad7616_sw_scale_avail);
/* After reset, in software mode, ±10 V is set by default */
memset32(st->range, 2, ARRAY_SIZE(st->range));
indio_dev->info = &ad7606_info_os_range_and_debug;
ret = st->bops->sw_mode_config(indio_dev);
if (ret < 0)
return ret;
}
st->trig = devm_iio_trigger_alloc(dev, "%s-dev%d",
indio_dev->name,
iio_device_id(indio_dev));
if (!st->trig)
return -ENOMEM;
st->trig->ops = &ad7606_trigger_ops;
iio_trigger_set_drvdata(st->trig, indio_dev);
ret = devm_iio_trigger_register(dev, st->trig);
if (ret)
return ret;
indio_dev->trig = iio_trigger_get(st->trig);
ret = devm_request_threaded_irq(dev, irq,
NULL,
&ad7606_interrupt,
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
name, indio_dev);
if (ret)
return ret;
ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
&iio_pollfunc_store_time,
&ad7606_trigger_handler,
&ad7606_buffer_ops);
if (ret)
return ret;
return devm_iio_device_register(dev, indio_dev);
}
EXPORT_SYMBOL_GPL(ad7606_probe);
#ifdef CONFIG_PM_SLEEP
static int ad7606_suspend(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad7606_state *st = iio_priv(indio_dev);
if (st->gpio_standby) {
gpiod_set_value(st->gpio_range, 1);
gpiod_set_value(st->gpio_standby, 0);
}
return 0;
}
static int ad7606_resume(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad7606_state *st = iio_priv(indio_dev);
if (st->gpio_standby) {
gpiod_set_value(st->gpio_range, st->range[0]);
gpiod_set_value(st->gpio_standby, 1);
ad7606_reset(st);
}
return 0;
}
SIMPLE_DEV_PM_OPS(ad7606_pm_ops, ad7606_suspend, ad7606_resume);
EXPORT_SYMBOL_GPL(ad7606_pm_ops);
#endif
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
MODULE_LICENSE("GPL v2");
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