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linux/drivers/iio/adc/ad7887.c
Jonathan Cameron 52b31bcc93 iio:adc: drop assign iio_info.driver_module and iio_trigger_ops.owner 
The equivalent of both of these are now done via macro magic when
the relevant register calls are made.  The actual structure
elements will shortly go away.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
2017-08-22 21:22:25 +01:00

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/*
* AD7887 SPI ADC driver
*
* Copyright 2010-2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/device.h>
#include <linux/kernel.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/module.h>
#include <linux/interrupt.h>
#include <linux/bitops.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>
#include <linux/platform_data/ad7887.h>
#define AD7887_REF_DIS BIT(5) /* on-chip reference disable */
#define AD7887_DUAL BIT(4) /* dual-channel mode */
#define AD7887_CH_AIN1 BIT(3) /* convert on channel 1, DUAL=1 */
#define AD7887_CH_AIN0 0 /* convert on channel 0, DUAL=0,1 */
#define AD7887_PM_MODE1 0 /* CS based shutdown */
#define AD7887_PM_MODE2 1 /* full on */
#define AD7887_PM_MODE3 2 /* auto shutdown after conversion */
#define AD7887_PM_MODE4 3 /* standby mode */
enum ad7887_channels {
AD7887_CH0,
AD7887_CH0_CH1,
AD7887_CH1,
};
/**
* struct ad7887_chip_info - chip specifc information
* @int_vref_mv: the internal reference voltage
* @channel: channel specification
*/
struct ad7887_chip_info {
u16 int_vref_mv;
struct iio_chan_spec channel[3];
};
struct ad7887_state {
struct spi_device *spi;
const struct ad7887_chip_info *chip_info;
struct regulator *reg;
struct spi_transfer xfer[4];
struct spi_message msg[3];
struct spi_message *ring_msg;
unsigned char tx_cmd_buf[4];
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
* Buffer needs to be large enough to hold two 16 bit samples and a
* 64 bit aligned 64 bit timestamp.
*/
unsigned char data[ALIGN(4, sizeof(s64)) + sizeof(s64)]
____cacheline_aligned;
};
enum ad7887_supported_device_ids {
ID_AD7887
};
static int ad7887_ring_preenable(struct iio_dev *indio_dev)
{
struct ad7887_state *st = iio_priv(indio_dev);
/* We know this is a single long so can 'cheat' */
switch (*indio_dev->active_scan_mask) {
case (1 << 0):
st->ring_msg = &st->msg[AD7887_CH0];
break;
case (1 << 1):
st->ring_msg = &st->msg[AD7887_CH1];
/* Dummy read: push CH1 setting down to hardware */
spi_sync(st->spi, st->ring_msg);
break;
case ((1 << 1) | (1 << 0)):
st->ring_msg = &st->msg[AD7887_CH0_CH1];
break;
}
return 0;
}
static int ad7887_ring_postdisable(struct iio_dev *indio_dev)
{
struct ad7887_state *st = iio_priv(indio_dev);
/* dummy read: restore default CH0 settin */
return spi_sync(st->spi, &st->msg[AD7887_CH0]);
}
/**
* ad7887_trigger_handler() bh of trigger launched polling to ring buffer
*
* Currently there is no option in this driver to disable the saving of
* timestamps within the ring.
**/
static irqreturn_t ad7887_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7887_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->data,
iio_get_time_ns(indio_dev));
done:
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static const struct iio_buffer_setup_ops ad7887_ring_setup_ops = {
.preenable = &ad7887_ring_preenable,
.postenable = &iio_triggered_buffer_postenable,
.predisable = &iio_triggered_buffer_predisable,
.postdisable = &ad7887_ring_postdisable,
};
static int ad7887_scan_direct(struct ad7887_state *st, unsigned ch)
{
int ret = spi_sync(st->spi, &st->msg[ch]);
if (ret)
return ret;
return (st->data[(ch * 2)] << 8) | st->data[(ch * 2) + 1];
}
static int ad7887_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad7887_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 = ad7887_scan_direct(st, chan->address);
iio_device_release_direct_mode(indio_dev);
if (ret < 0)
return ret;
*val = ret >> chan->scan_type.shift;
*val &= GENMASK(chan->scan_type.realbits - 1, 0);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (st->reg) {
*val = regulator_get_voltage(st->reg);
if (*val < 0)
return *val;
*val /= 1000;
} else {
*val = st->chip_info->int_vref_mv;
}
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
static const struct ad7887_chip_info ad7887_chip_info_tbl[] = {
/*
* More devices added in future
*/
[ID_AD7887] = {
.channel[0] = {
.type = IIO_VOLTAGE,
.indexed = 1,
.channel = 1,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.address = 1,
.scan_index = 1,
.scan_type = {
.sign = 'u',
.realbits = 12,
.storagebits = 16,
.shift = 0,
.endianness = IIO_BE,
},
},
.channel[1] = {
.type = IIO_VOLTAGE,
.indexed = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
.address = 0,
.scan_index = 0,
.scan_type = {
.sign = 'u',
.realbits = 12,
.storagebits = 16,
.shift = 0,
.endianness = IIO_BE,
},
},
.channel[2] = IIO_CHAN_SOFT_TIMESTAMP(2),
.int_vref_mv = 2500,
},
};
static const struct iio_info ad7887_info = {
.read_raw = &ad7887_read_raw,
};
static int ad7887_probe(struct spi_device *spi)
{
struct ad7887_platform_data *pdata = spi->dev.platform_data;
struct ad7887_state *st;
struct iio_dev *indio_dev;
uint8_t mode;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
if (!pdata || !pdata->use_onchip_ref) {
st->reg = devm_regulator_get(&spi->dev, "vref");
if (IS_ERR(st->reg))
return PTR_ERR(st->reg);
ret = regulator_enable(st->reg);
if (ret)
return ret;
}
st->chip_info =
&ad7887_chip_info_tbl[spi_get_device_id(spi)->driver_data];
spi_set_drvdata(spi, indio_dev);
st->spi = spi;
/* Estabilish that the iio_dev is a child of the spi device */
indio_dev->dev.parent = &spi->dev;
indio_dev->dev.of_node = spi->dev.of_node;
indio_dev->name = spi_get_device_id(spi)->name;
indio_dev->info = &ad7887_info;
indio_dev->modes = INDIO_DIRECT_MODE;
/* Setup default message */
mode = AD7887_PM_MODE4;
if (!pdata || !pdata->use_onchip_ref)
mode |= AD7887_REF_DIS;
if (pdata && pdata->en_dual)
mode |= AD7887_DUAL;
st->tx_cmd_buf[0] = AD7887_CH_AIN0 | mode;
st->xfer[0].rx_buf = &st->data[0];
st->xfer[0].tx_buf = &st->tx_cmd_buf[0];
st->xfer[0].len = 2;
spi_message_init(&st->msg[AD7887_CH0]);
spi_message_add_tail(&st->xfer[0], &st->msg[AD7887_CH0]);
if (pdata && pdata->en_dual) {
st->tx_cmd_buf[2] = AD7887_CH_AIN1 | mode;
st->xfer[1].rx_buf = &st->data[0];
st->xfer[1].tx_buf = &st->tx_cmd_buf[2];
st->xfer[1].len = 2;
st->xfer[2].rx_buf = &st->data[2];
st->xfer[2].tx_buf = &st->tx_cmd_buf[0];
st->xfer[2].len = 2;
spi_message_init(&st->msg[AD7887_CH0_CH1]);
spi_message_add_tail(&st->xfer[1], &st->msg[AD7887_CH0_CH1]);
spi_message_add_tail(&st->xfer[2], &st->msg[AD7887_CH0_CH1]);
st->xfer[3].rx_buf = &st->data[2];
st->xfer[3].tx_buf = &st->tx_cmd_buf[2];
st->xfer[3].len = 2;
spi_message_init(&st->msg[AD7887_CH1]);
spi_message_add_tail(&st->xfer[3], &st->msg[AD7887_CH1]);
indio_dev->channels = st->chip_info->channel;
indio_dev->num_channels = 3;
} else {
indio_dev->channels = &st->chip_info->channel[1];
indio_dev->num_channels = 2;
}
ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time,
&ad7887_trigger_handler, &ad7887_ring_setup_ops);
if (ret)
goto error_disable_reg;
ret = iio_device_register(indio_dev);
if (ret)
goto error_unregister_ring;
return 0;
error_unregister_ring:
iio_triggered_buffer_cleanup(indio_dev);
error_disable_reg:
if (st->reg)
regulator_disable(st->reg);
return ret;
}
static int ad7887_remove(struct spi_device *spi)
{
struct iio_dev *indio_dev = spi_get_drvdata(spi);
struct ad7887_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
if (st->reg)
regulator_disable(st->reg);
return 0;
}
static const struct spi_device_id ad7887_id[] = {
{"ad7887", ID_AD7887},
{}
};
MODULE_DEVICE_TABLE(spi, ad7887_id);
static struct spi_driver ad7887_driver = {
.driver = {
.name = "ad7887",
},
.probe = ad7887_probe,
.remove = ad7887_remove,
.id_table = ad7887_id,
};
module_spi_driver(ad7887_driver);
MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
MODULE_DESCRIPTION("Analog Devices AD7887 ADC");
MODULE_LICENSE("GPL v2");
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