// SPDX-License-Identifier: GPL-2.0-only
/*
* AD7904/AD7914/AD7923/AD7924/AD7908/AD7918/AD7928 SPI ADC driver
*
* Copyright 2011 Analog Devices Inc (from AD7923 Driver)
* Copyright 2012 CS Systemes d'Information
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/spi/spi.h>
#include <linux/regulator/consumer.h>
#include <linux/err.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#define AD7923_WRITE_CR BIT(11) /* write control register */
#define AD7923_RANGE BIT(1) /* range to REFin */
#define AD7923_CODING BIT(0) /* coding is straight binary */
#define AD7923_PM_MODE_AS (1) /* auto shutdown */
#define AD7923_PM_MODE_FS (2) /* full shutdown */
#define AD7923_PM_MODE_OPS (3) /* normal operation */
#define AD7923_SEQUENCE_OFF (0) /* no sequence fonction */
#define AD7923_SEQUENCE_PROTECT (2) /* no interrupt write cycle */
#define AD7923_SEQUENCE_ON (3) /* continuous sequence */
#define AD7923_PM_MODE_WRITE(mode) ((mode) << 4) /* write mode */
#define AD7923_CHANNEL_WRITE(channel) ((channel) << 6) /* write channel */
#define AD7923_SEQUENCE_WRITE(sequence) ((((sequence) & 1) << 3) \
+ (((sequence) & 2) << 9))
/* write sequence fonction */
/* left shift for CR : bit 11 transmit in first */
#define AD7923_SHIFT_REGISTER 4
/* val = value, dec = left shift, bits = number of bits of the mask */
#define EXTRACT(val, dec, bits) (((val) >> (dec)) & ((1 << (bits)) - 1))
struct ad7923_state {
struct spi_device *spi;
struct spi_transfer ring_xfer[5];
struct spi_transfer scan_single_xfer[2];
struct spi_message ring_msg;
struct spi_message scan_single_msg;
struct regulator *reg;
unsigned int settings;
/*
* DMA (thus cache coherency maintenance) may require the
* transfer buffers to live in their own cache lines.
* Ensure rx_buf can be directly used in iio_push_to_buffers_with_timetamp
* Length = 8 channels + 4 extra for 8 byte timestamp
*/
__be16 rx_buf[12] __aligned(IIO_DMA_MINALIGN);
__be16 tx_buf[4];
};
struct ad7923_chip_info {
const struct iio_chan_spec *channels;
unsigned int num_channels;
};
enum ad7923_id {
AD7904,
AD7914,
AD7924,
AD7908,
AD7918,
AD7928
};
#define AD7923_V_CHAN(index, bits) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = index, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.address = index, \
.scan_index = index, \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = 12 - (bits), \
.endianness = IIO_BE, \
}, \
}
#define DECLARE_AD7923_CHANNELS(name, bits) \
const struct iio_chan_spec name ## _channels[] = { \
AD7923_V_CHAN(0, bits), \
AD7923_V_CHAN(1, bits), \
AD7923_V_CHAN(2, bits), \
AD7923_V_CHAN(3, bits), \
IIO_CHAN_SOFT_TIMESTAMP(4), \
}
#define DECLARE_AD7908_CHANNELS(name, bits) \
const struct iio_chan_spec name ## _channels[] = { \
AD7923_V_CHAN(0, bits), \
AD7923_V_CHAN(1, bits), \
AD7923_V_CHAN(2, bits), \
AD7923_V_CHAN(3, bits), \
AD7923_V_CHAN(4, bits), \
AD7923_V_CHAN(5, bits), \
AD7923_V_CHAN(6, bits), \
AD7923_V_CHAN(7, bits), \
IIO_CHAN_SOFT_TIMESTAMP(8), \
}
static DECLARE_AD7923_CHANNELS(ad7904, 8);
static DECLARE_AD7923_CHANNELS(ad7914, 10);
static DECLARE_AD7923_CHANNELS(ad7924, 12);
static DECLARE_AD7908_CHANNELS(ad7908, 8);
static DECLARE_AD7908_CHANNELS(ad7918, 10);
static DECLARE_AD7908_CHANNELS(ad7928, 12);
static const struct ad7923_chip_info ad7923_chip_info[] = {
[AD7904] = {
.channels = ad7904_channels,
.num_channels = ARRAY_SIZE(ad7904_channels),
},
[AD7914] = {
.channels = ad7914_channels,
.num_channels = ARRAY_SIZE(ad7914_channels),
},
[AD7924] = {
.channels = ad7924_channels,
.num_channels = ARRAY_SIZE(ad7924_channels),
},
[AD7908] = {
.channels = ad7908_channels,
.num_channels = ARRAY_SIZE(ad7908_channels),
},
[AD7918] = {
.channels = ad7918_channels,
.num_channels = ARRAY_SIZE(ad7918_channels),
},
[AD7928] = {
.channels = ad7928_channels,
.num_channels = ARRAY_SIZE(ad7928_channels),
},
};
/*
* ad7923_update_scan_mode() setup the spi transfer buffer for the new scan mask
*/
static int ad7923_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *active_scan_mask)
{
struct ad7923_state *st = iio_priv(indio_dev);
int i, cmd, len;
len = 0;
/*
* For this driver the last channel is always the software timestamp so
* skip that one.
*/
for_each_set_bit(i, active_scan_mask, indio_dev->num_channels - 1) {
cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(i) |
AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
st->settings;
cmd <<= AD7923_SHIFT_REGISTER;
st->tx_buf[len++] = cpu_to_be16(cmd);
}
/* build spi ring message */
st->ring_xfer[0].tx_buf = &st->tx_buf[0];
st->ring_xfer[0].len = len;
st->ring_xfer[0].cs_change = 1;
spi_message_init(&st->ring_msg);
spi_message_add_tail(&st->ring_xfer[0], &st->ring_msg);
for (i = 0; i < len; i++) {
st->ring_xfer[i + 1].rx_buf = &st->rx_buf[i];
st->ring_xfer[i + 1].len = 2;
st->ring_xfer[i + 1].cs_change = 1;
spi_message_add_tail(&st->ring_xfer[i + 1], &st->ring_msg);
}
/* make sure last transfer cs_change is not set */
st->ring_xfer[i + 1].cs_change = 0;
return 0;
}
static irqreturn_t ad7923_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7923_state *st = iio_priv(indio_dev);
int b_sent;
b_sent = spi_sync(st->spi, &st->ring_msg);
if (b_sent)
goto done;
iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
iio_get_time_ns(indio_dev));
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static int ad7923_scan_direct(struct ad7923_state *st, unsigned int ch)
{
int ret, cmd;
cmd = AD7923_WRITE_CR | AD7923_CHANNEL_WRITE(ch) |
AD7923_SEQUENCE_WRITE(AD7923_SEQUENCE_OFF) |
st->settings;
cmd <<= AD7923_SHIFT_REGISTER;
st->tx_buf[0] = cpu_to_be16(cmd);
ret = spi_sync(st->spi, &st->scan_single_msg);
if (ret)
return ret;
return be16_to_cpu(st->rx_buf[0]);
}
static int ad7923_get_range(struct ad7923_state *st)
{
int vref;
vref = regulator_get_voltage(st->reg);
if (vref < 0)
return vref;
vref /= 1000;
if (!(st->settings & AD7923_RANGE))
vref *= 2;
return vref;
}
static int ad7923_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad7923_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 = ad7923_scan_direct(st, chan->address);
iio_device_release_direct_mode(indio_dev);
if (ret < 0)
return ret;
if (chan->address == EXTRACT(ret, 12, 4))
*val = EXTRACT(ret, chan->scan_type.shift,
chan->scan_type.realbits);
else
return -EIO;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
ret = ad7923_get_range(st);
if (ret < 0)
return ret;
*val = ret;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static const struct iio_info ad7923_info = {
.read_raw = &ad7923_read_raw,
.update_scan_mode = ad7923_update_scan_mode,
};
static void ad7923_regulator_disable(void *data)
{
struct ad7923_state *st = data;
regulator_disable(st->reg);
}
static int ad7923_probe(struct spi_device *spi)
{
u32 ad7923_range = AD7923_RANGE;
struct ad7923_state *st;
struct iio_dev *indio_dev;
const struct ad7923_chip_info *info;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
if (device_property_read_bool(&spi->dev, "adi,range-double"))
ad7923_range = 0;
st->spi = spi;
st->settings = AD7923_CODING | ad7923_range |
AD7923_PM_MODE_WRITE(AD7923_PM_MODE_OPS);
info = &ad7923_chip_info[spi_get_device_id(spi)->driver_data];
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = info->channels;
indio_dev->num_channels = info->num_channels;
indio_dev->info = &ad7923_info;
/* Setup default message */
st->scan_single_xfer[0].tx_buf = &st->tx_buf[0];
st->scan_single_xfer[0].len = 2;
st->scan_single_xfer[0].cs_change = 1;
st->scan_single_xfer[1].rx_buf = &st->rx_buf[0];
st->scan_single_xfer[1].len = 2;
spi_message_init(&st->scan_single_msg);
spi_message_add_tail(&st->scan_single_xfer[0], &st->scan_single_msg);
spi_message_add_tail(&st->scan_single_xfer[1], &st->scan_single_msg);
st->reg = devm_regulator_get(&spi->dev, "refin");
if (IS_ERR(st->reg))
return PTR_ERR(st->reg);
ret = regulator_enable(st->reg);
if (ret)
return ret;
ret = devm_add_action_or_reset(&spi->dev, ad7923_regulator_disable, st);
if (ret)
return ret;
ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
&ad7923_trigger_handler, NULL);
if (ret)
return ret;
return devm_iio_device_register(&spi->dev, indio_dev);
}
static const struct spi_device_id ad7923_id[] = {
{ "ad7904", AD7904 },
{ "ad7914", AD7914 },
{ "ad7923", AD7924 },
{ "ad7924", AD7924 },
{ "ad7908", AD7908 },
{ "ad7918", AD7918 },
{ "ad7928", AD7928 },
{ }
};
MODULE_DEVICE_TABLE(spi, ad7923_id);
static const struct of_device_id ad7923_of_match[] = {
{ .compatible = "adi,ad7904", },
{ .compatible = "adi,ad7914", },
{ .compatible = "adi,ad7923", },
{ .compatible = "adi,ad7924", },
{ .compatible = "adi,ad7908", },
{ .compatible = "adi,ad7918", },
{ .compatible = "adi,ad7928", },
{ }
};
MODULE_DEVICE_TABLE(of, ad7923_of_match);
static struct spi_driver ad7923_driver = {
.driver = {
.name = "ad7923",
.of_match_table = ad7923_of_match,
},
.probe = ad7923_probe,
.id_table = ad7923_id,
};
module_spi_driver(ad7923_driver);
MODULE_AUTHOR("Michael Hennerich <[email protected]>");
MODULE_AUTHOR("Patrick Vasseur <[email protected]>");
MODULE_DESCRIPTION("Analog Devices AD7923 and similar ADC");
MODULE_LICENSE("GPL v2");
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