514 lines
13 KiB
C
514 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* AD7266/65 SPI ADC driver
|
|
*
|
|
* Copyright 2012 Analog Devices Inc.
|
|
*/
|
|
|
|
#include <linux/device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/spi/spi.h>
|
|
#include <linux/regulator/consumer.h>
|
|
#include <linux/err.h>
|
|
#include <linux/gpio/consumer.h>
|
|
#include <linux/module.h>
|
|
|
|
#include <linux/interrupt.h>
|
|
|
|
#include <linux/iio/iio.h>
|
|
#include <linux/iio/buffer.h>
|
|
#include <linux/iio/trigger_consumer.h>
|
|
#include <linux/iio/triggered_buffer.h>
|
|
|
|
#include <linux/platform_data/ad7266.h>
|
|
|
|
struct ad7266_state {
|
|
struct spi_device *spi;
|
|
struct regulator *reg;
|
|
unsigned long vref_mv;
|
|
|
|
struct spi_transfer single_xfer[3];
|
|
struct spi_message single_msg;
|
|
|
|
enum ad7266_range range;
|
|
enum ad7266_mode mode;
|
|
bool fixed_addr;
|
|
struct gpio_desc *gpios[3];
|
|
|
|
/*
|
|
* DMA (thus cache coherency maintenance) requires the
|
|
* transfer buffers to live in their own cache lines.
|
|
* The buffer needs to be large enough to hold two samples (4 bytes) and
|
|
* the naturally aligned timestamp (8 bytes).
|
|
*/
|
|
struct {
|
|
__be16 sample[2];
|
|
s64 timestamp;
|
|
} data ____cacheline_aligned;
|
|
};
|
|
|
|
static int ad7266_wakeup(struct ad7266_state *st)
|
|
{
|
|
/* Any read with >= 2 bytes will wake the device */
|
|
return spi_read(st->spi, &st->data.sample[0], 2);
|
|
}
|
|
|
|
static int ad7266_powerdown(struct ad7266_state *st)
|
|
{
|
|
/* Any read with < 2 bytes will powerdown the device */
|
|
return spi_read(st->spi, &st->data.sample[0], 1);
|
|
}
|
|
|
|
static int ad7266_preenable(struct iio_dev *indio_dev)
|
|
{
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
return ad7266_wakeup(st);
|
|
}
|
|
|
|
static int ad7266_postdisable(struct iio_dev *indio_dev)
|
|
{
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
return ad7266_powerdown(st);
|
|
}
|
|
|
|
static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
|
|
.preenable = &ad7266_preenable,
|
|
.postdisable = &ad7266_postdisable,
|
|
};
|
|
|
|
static irqreturn_t ad7266_trigger_handler(int irq, void *p)
|
|
{
|
|
struct iio_poll_func *pf = p;
|
|
struct iio_dev *indio_dev = pf->indio_dev;
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
int ret;
|
|
|
|
ret = spi_read(st->spi, st->data.sample, 4);
|
|
if (ret == 0) {
|
|
iio_push_to_buffers_with_timestamp(indio_dev, &st->data,
|
|
pf->timestamp);
|
|
}
|
|
|
|
iio_trigger_notify_done(indio_dev->trig);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
static void ad7266_select_input(struct ad7266_state *st, unsigned int nr)
|
|
{
|
|
unsigned int i;
|
|
|
|
if (st->fixed_addr)
|
|
return;
|
|
|
|
switch (st->mode) {
|
|
case AD7266_MODE_SINGLE_ENDED:
|
|
nr >>= 1;
|
|
break;
|
|
case AD7266_MODE_PSEUDO_DIFF:
|
|
nr |= 1;
|
|
break;
|
|
case AD7266_MODE_DIFF:
|
|
nr &= ~1;
|
|
break;
|
|
}
|
|
|
|
for (i = 0; i < 3; ++i)
|
|
gpiod_set_value(st->gpios[i], (bool)(nr & BIT(i)));
|
|
}
|
|
|
|
static int ad7266_update_scan_mode(struct iio_dev *indio_dev,
|
|
const unsigned long *scan_mask)
|
|
{
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
unsigned int nr = find_first_bit(scan_mask, indio_dev->masklength);
|
|
|
|
ad7266_select_input(st, nr);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int ad7266_read_single(struct ad7266_state *st, int *val,
|
|
unsigned int address)
|
|
{
|
|
int ret;
|
|
|
|
ad7266_select_input(st, address);
|
|
|
|
ret = spi_sync(st->spi, &st->single_msg);
|
|
*val = be16_to_cpu(st->data.sample[address % 2]);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ad7266_read_raw(struct iio_dev *indio_dev,
|
|
struct iio_chan_spec const *chan, int *val, int *val2, long m)
|
|
{
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
unsigned long scale_mv;
|
|
int ret;
|
|
|
|
switch (m) {
|
|
case IIO_CHAN_INFO_RAW:
|
|
ret = iio_device_claim_direct_mode(indio_dev);
|
|
if (ret)
|
|
return ret;
|
|
ret = ad7266_read_single(st, val, chan->address);
|
|
iio_device_release_direct_mode(indio_dev);
|
|
|
|
*val = (*val >> 2) & 0xfff;
|
|
if (chan->scan_type.sign == 's')
|
|
*val = sign_extend32(*val, 11);
|
|
|
|
return IIO_VAL_INT;
|
|
case IIO_CHAN_INFO_SCALE:
|
|
scale_mv = st->vref_mv;
|
|
if (st->mode == AD7266_MODE_DIFF)
|
|
scale_mv *= 2;
|
|
if (st->range == AD7266_RANGE_2VREF)
|
|
scale_mv *= 2;
|
|
|
|
*val = scale_mv;
|
|
*val2 = chan->scan_type.realbits;
|
|
return IIO_VAL_FRACTIONAL_LOG2;
|
|
case IIO_CHAN_INFO_OFFSET:
|
|
if (st->range == AD7266_RANGE_2VREF &&
|
|
st->mode != AD7266_MODE_DIFF)
|
|
*val = 2048;
|
|
else
|
|
*val = 0;
|
|
return IIO_VAL_INT;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
#define AD7266_CHAN(_chan, _sign) { \
|
|
.type = IIO_VOLTAGE, \
|
|
.indexed = 1, \
|
|
.channel = (_chan), \
|
|
.address = (_chan), \
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
|
|
| BIT(IIO_CHAN_INFO_OFFSET), \
|
|
.scan_index = (_chan), \
|
|
.scan_type = { \
|
|
.sign = (_sign), \
|
|
.realbits = 12, \
|
|
.storagebits = 16, \
|
|
.shift = 2, \
|
|
.endianness = IIO_BE, \
|
|
}, \
|
|
}
|
|
|
|
#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS(_name, _sign) \
|
|
const struct iio_chan_spec ad7266_channels_##_name[] = { \
|
|
AD7266_CHAN(0, (_sign)), \
|
|
AD7266_CHAN(1, (_sign)), \
|
|
AD7266_CHAN(2, (_sign)), \
|
|
AD7266_CHAN(3, (_sign)), \
|
|
AD7266_CHAN(4, (_sign)), \
|
|
AD7266_CHAN(5, (_sign)), \
|
|
AD7266_CHAN(6, (_sign)), \
|
|
AD7266_CHAN(7, (_sign)), \
|
|
AD7266_CHAN(8, (_sign)), \
|
|
AD7266_CHAN(9, (_sign)), \
|
|
AD7266_CHAN(10, (_sign)), \
|
|
AD7266_CHAN(11, (_sign)), \
|
|
IIO_CHAN_SOFT_TIMESTAMP(13), \
|
|
}
|
|
|
|
#define AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(_name, _sign) \
|
|
const struct iio_chan_spec ad7266_channels_##_name##_fixed[] = { \
|
|
AD7266_CHAN(0, (_sign)), \
|
|
AD7266_CHAN(1, (_sign)), \
|
|
IIO_CHAN_SOFT_TIMESTAMP(2), \
|
|
}
|
|
|
|
static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(u, 'u');
|
|
static AD7266_DECLARE_SINGLE_ENDED_CHANNELS(s, 's');
|
|
static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(u, 'u');
|
|
static AD7266_DECLARE_SINGLE_ENDED_CHANNELS_FIXED(s, 's');
|
|
|
|
#define AD7266_CHAN_DIFF(_chan, _sign) { \
|
|
.type = IIO_VOLTAGE, \
|
|
.indexed = 1, \
|
|
.channel = (_chan) * 2, \
|
|
.channel2 = (_chan) * 2 + 1, \
|
|
.address = (_chan), \
|
|
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
|
|
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
|
|
| BIT(IIO_CHAN_INFO_OFFSET), \
|
|
.scan_index = (_chan), \
|
|
.scan_type = { \
|
|
.sign = _sign, \
|
|
.realbits = 12, \
|
|
.storagebits = 16, \
|
|
.shift = 2, \
|
|
.endianness = IIO_BE, \
|
|
}, \
|
|
.differential = 1, \
|
|
}
|
|
|
|
#define AD7266_DECLARE_DIFF_CHANNELS(_name, _sign) \
|
|
const struct iio_chan_spec ad7266_channels_diff_##_name[] = { \
|
|
AD7266_CHAN_DIFF(0, (_sign)), \
|
|
AD7266_CHAN_DIFF(1, (_sign)), \
|
|
AD7266_CHAN_DIFF(2, (_sign)), \
|
|
AD7266_CHAN_DIFF(3, (_sign)), \
|
|
AD7266_CHAN_DIFF(4, (_sign)), \
|
|
AD7266_CHAN_DIFF(5, (_sign)), \
|
|
IIO_CHAN_SOFT_TIMESTAMP(6), \
|
|
}
|
|
|
|
static AD7266_DECLARE_DIFF_CHANNELS(s, 's');
|
|
static AD7266_DECLARE_DIFF_CHANNELS(u, 'u');
|
|
|
|
#define AD7266_DECLARE_DIFF_CHANNELS_FIXED(_name, _sign) \
|
|
const struct iio_chan_spec ad7266_channels_diff_fixed_##_name[] = { \
|
|
AD7266_CHAN_DIFF(0, (_sign)), \
|
|
AD7266_CHAN_DIFF(1, (_sign)), \
|
|
IIO_CHAN_SOFT_TIMESTAMP(2), \
|
|
}
|
|
|
|
static AD7266_DECLARE_DIFF_CHANNELS_FIXED(s, 's');
|
|
static AD7266_DECLARE_DIFF_CHANNELS_FIXED(u, 'u');
|
|
|
|
static const struct iio_info ad7266_info = {
|
|
.read_raw = &ad7266_read_raw,
|
|
.update_scan_mode = &ad7266_update_scan_mode,
|
|
};
|
|
|
|
static const unsigned long ad7266_available_scan_masks[] = {
|
|
0x003,
|
|
0x00c,
|
|
0x030,
|
|
0x0c0,
|
|
0x300,
|
|
0xc00,
|
|
0x000,
|
|
};
|
|
|
|
static const unsigned long ad7266_available_scan_masks_diff[] = {
|
|
0x003,
|
|
0x00c,
|
|
0x030,
|
|
0x000,
|
|
};
|
|
|
|
static const unsigned long ad7266_available_scan_masks_fixed[] = {
|
|
0x003,
|
|
0x000,
|
|
};
|
|
|
|
struct ad7266_chan_info {
|
|
const struct iio_chan_spec *channels;
|
|
unsigned int num_channels;
|
|
const unsigned long *scan_masks;
|
|
};
|
|
|
|
#define AD7266_CHAN_INFO_INDEX(_differential, _signed, _fixed) \
|
|
(((_differential) << 2) | ((_signed) << 1) | ((_fixed) << 0))
|
|
|
|
static const struct ad7266_chan_info ad7266_chan_infos[] = {
|
|
[AD7266_CHAN_INFO_INDEX(0, 0, 0)] = {
|
|
.channels = ad7266_channels_u,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_u),
|
|
.scan_masks = ad7266_available_scan_masks,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(0, 0, 1)] = {
|
|
.channels = ad7266_channels_u_fixed,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_u_fixed),
|
|
.scan_masks = ad7266_available_scan_masks_fixed,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(0, 1, 0)] = {
|
|
.channels = ad7266_channels_s,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_s),
|
|
.scan_masks = ad7266_available_scan_masks,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(0, 1, 1)] = {
|
|
.channels = ad7266_channels_s_fixed,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_s_fixed),
|
|
.scan_masks = ad7266_available_scan_masks_fixed,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(1, 0, 0)] = {
|
|
.channels = ad7266_channels_diff_u,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_diff_u),
|
|
.scan_masks = ad7266_available_scan_masks_diff,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(1, 0, 1)] = {
|
|
.channels = ad7266_channels_diff_fixed_u,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_u),
|
|
.scan_masks = ad7266_available_scan_masks_fixed,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(1, 1, 0)] = {
|
|
.channels = ad7266_channels_diff_s,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_diff_s),
|
|
.scan_masks = ad7266_available_scan_masks_diff,
|
|
},
|
|
[AD7266_CHAN_INFO_INDEX(1, 1, 1)] = {
|
|
.channels = ad7266_channels_diff_fixed_s,
|
|
.num_channels = ARRAY_SIZE(ad7266_channels_diff_fixed_s),
|
|
.scan_masks = ad7266_available_scan_masks_fixed,
|
|
},
|
|
};
|
|
|
|
static void ad7266_init_channels(struct iio_dev *indio_dev)
|
|
{
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
bool is_differential, is_signed;
|
|
const struct ad7266_chan_info *chan_info;
|
|
int i;
|
|
|
|
is_differential = st->mode != AD7266_MODE_SINGLE_ENDED;
|
|
is_signed = (st->range == AD7266_RANGE_2VREF) |
|
|
(st->mode == AD7266_MODE_DIFF);
|
|
|
|
i = AD7266_CHAN_INFO_INDEX(is_differential, is_signed, st->fixed_addr);
|
|
chan_info = &ad7266_chan_infos[i];
|
|
|
|
indio_dev->channels = chan_info->channels;
|
|
indio_dev->num_channels = chan_info->num_channels;
|
|
indio_dev->available_scan_masks = chan_info->scan_masks;
|
|
indio_dev->masklength = chan_info->num_channels - 1;
|
|
}
|
|
|
|
static const char * const ad7266_gpio_labels[] = {
|
|
"ad0", "ad1", "ad2",
|
|
};
|
|
|
|
static int ad7266_probe(struct spi_device *spi)
|
|
{
|
|
struct ad7266_platform_data *pdata = spi->dev.platform_data;
|
|
struct iio_dev *indio_dev;
|
|
struct ad7266_state *st;
|
|
unsigned int i;
|
|
int ret;
|
|
|
|
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
|
|
if (indio_dev == NULL)
|
|
return -ENOMEM;
|
|
|
|
st = iio_priv(indio_dev);
|
|
|
|
st->reg = devm_regulator_get_optional(&spi->dev, "vref");
|
|
if (!IS_ERR(st->reg)) {
|
|
ret = regulator_enable(st->reg);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = regulator_get_voltage(st->reg);
|
|
if (ret < 0)
|
|
goto error_disable_reg;
|
|
|
|
st->vref_mv = ret / 1000;
|
|
} else {
|
|
/* Any other error indicates that the regulator does exist */
|
|
if (PTR_ERR(st->reg) != -ENODEV)
|
|
return PTR_ERR(st->reg);
|
|
/* Use internal reference */
|
|
st->vref_mv = 2500;
|
|
}
|
|
|
|
if (pdata) {
|
|
st->fixed_addr = pdata->fixed_addr;
|
|
st->mode = pdata->mode;
|
|
st->range = pdata->range;
|
|
|
|
if (!st->fixed_addr) {
|
|
for (i = 0; i < ARRAY_SIZE(st->gpios); ++i) {
|
|
st->gpios[i] = devm_gpiod_get(&spi->dev,
|
|
ad7266_gpio_labels[i],
|
|
GPIOD_OUT_LOW);
|
|
if (IS_ERR(st->gpios[i])) {
|
|
ret = PTR_ERR(st->gpios[i]);
|
|
goto error_disable_reg;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
st->fixed_addr = true;
|
|
st->range = AD7266_RANGE_VREF;
|
|
st->mode = AD7266_MODE_DIFF;
|
|
}
|
|
|
|
spi_set_drvdata(spi, indio_dev);
|
|
st->spi = spi;
|
|
|
|
indio_dev->name = spi_get_device_id(spi)->name;
|
|
indio_dev->modes = INDIO_DIRECT_MODE;
|
|
indio_dev->info = &ad7266_info;
|
|
|
|
ad7266_init_channels(indio_dev);
|
|
|
|
/* wakeup */
|
|
st->single_xfer[0].rx_buf = &st->data.sample[0];
|
|
st->single_xfer[0].len = 2;
|
|
st->single_xfer[0].cs_change = 1;
|
|
/* conversion */
|
|
st->single_xfer[1].rx_buf = st->data.sample;
|
|
st->single_xfer[1].len = 4;
|
|
st->single_xfer[1].cs_change = 1;
|
|
/* powerdown */
|
|
st->single_xfer[2].tx_buf = &st->data.sample[0];
|
|
st->single_xfer[2].len = 1;
|
|
|
|
spi_message_init(&st->single_msg);
|
|
spi_message_add_tail(&st->single_xfer[0], &st->single_msg);
|
|
spi_message_add_tail(&st->single_xfer[1], &st->single_msg);
|
|
spi_message_add_tail(&st->single_xfer[2], &st->single_msg);
|
|
|
|
ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
|
|
&ad7266_trigger_handler, &iio_triggered_buffer_setup_ops);
|
|
if (ret)
|
|
goto error_disable_reg;
|
|
|
|
ret = iio_device_register(indio_dev);
|
|
if (ret)
|
|
goto error_buffer_cleanup;
|
|
|
|
return 0;
|
|
|
|
error_buffer_cleanup:
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
error_disable_reg:
|
|
if (!IS_ERR(st->reg))
|
|
regulator_disable(st->reg);
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int ad7266_remove(struct spi_device *spi)
|
|
{
|
|
struct iio_dev *indio_dev = spi_get_drvdata(spi);
|
|
struct ad7266_state *st = iio_priv(indio_dev);
|
|
|
|
iio_device_unregister(indio_dev);
|
|
iio_triggered_buffer_cleanup(indio_dev);
|
|
if (!IS_ERR(st->reg))
|
|
regulator_disable(st->reg);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct spi_device_id ad7266_id[] = {
|
|
{"ad7265", 0},
|
|
{"ad7266", 0},
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(spi, ad7266_id);
|
|
|
|
static struct spi_driver ad7266_driver = {
|
|
.driver = {
|
|
.name = "ad7266",
|
|
},
|
|
.probe = ad7266_probe,
|
|
.remove = ad7266_remove,
|
|
.id_table = ad7266_id,
|
|
};
|
|
module_spi_driver(ad7266_driver);
|
|
|
|
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
|
|
MODULE_DESCRIPTION("Analog Devices AD7266/65 ADC");
|
|
MODULE_LICENSE("GPL v2");
|