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linux/drivers/iio/adc/ad7476.c
Colin Ian King a66904b209 iio: adc: ad7476: remove redundant null check on an array 
The null check on st->chip_info->convst_channel is redundant because
convst_channel is a 2 element array of struct iio_chan_spec objects
and this can never be null. Fix this by removing the null check.

Addresses-Coverity: ("Array compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2020-05-03 09:47:21 +01:00

387 lines
9.1 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* Analog Devices AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver
* TI ADC081S/ADC101S/ADC121S 8/10/12-bit SPI ADC driver
*
* Copyright 2010 Analog Devices Inc.
*/
#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/gpio/consumer.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/bitops.h>
#include <linux/delay.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>
struct ad7476_state;
struct ad7476_chip_info {
unsigned int int_vref_uv;
struct iio_chan_spec channel[2];
/* channels used when convst gpio is defined */
struct iio_chan_spec convst_channel[2];
void (*reset)(struct ad7476_state *);
};
struct ad7476_state {
struct spi_device *spi;
const struct ad7476_chip_info *chip_info;
struct regulator *reg;
struct gpio_desc *convst_gpio;
struct spi_transfer xfer;
struct spi_message msg;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
* Make the buffer large enough for one 16 bit sample and one 64 bit
* aligned 64 bit timestamp.
*/
unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)]
____cacheline_aligned;
};
enum ad7476_supported_device_ids {
ID_AD7091R,
ID_AD7276,
ID_AD7277,
ID_AD7278,
ID_AD7466,
ID_AD7467,
ID_AD7468,
ID_AD7495,
ID_AD7940,
ID_ADC081S,
ID_ADC101S,
ID_ADC121S,
ID_ADS7866,
ID_ADS7867,
ID_ADS7868,
};
static void ad7091_convst(struct ad7476_state *st)
{
if (!st->convst_gpio)
return;
gpiod_set_value(st->convst_gpio, 0);
udelay(1); /* CONVST pulse width: 10 ns min */
gpiod_set_value(st->convst_gpio, 1);
udelay(1); /* Conversion time: 650 ns max */
}
static irqreturn_t ad7476_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct ad7476_state *st = iio_priv(indio_dev);
int b_sent;
ad7091_convst(st);
b_sent = spi_sync(st->spi, &st->msg);
if (b_sent < 0)
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 void ad7091_reset(struct ad7476_state *st)
{
/* Any transfers with 8 scl cycles will reset the device */
spi_read(st->spi, st->data, 1);
}
static int ad7476_scan_direct(struct ad7476_state *st)
{
int ret;
ad7091_convst(st);
ret = spi_sync(st->spi, &st->msg);
if (ret)
return ret;
return be16_to_cpup((__be16 *)st->data);
}
static int ad7476_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
int ret;
struct ad7476_state *st = iio_priv(indio_dev);
int scale_uv;
switch (m) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
ret = ad7476_scan_direct(st);
iio_device_release_direct_mode(indio_dev);
if (ret < 0)
return ret;
*val = (ret >> st->chip_info->channel[0].scan_type.shift) &
GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
if (!st->chip_info->int_vref_uv) {
scale_uv = regulator_get_voltage(st->reg);
if (scale_uv < 0)
return scale_uv;
} else {
scale_uv = st->chip_info->int_vref_uv;
}
*val = scale_uv / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
}
return -EINVAL;
}
#define _AD7476_CHAN(bits, _shift, _info_mask_sep) \
{ \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.info_mask_separate = _info_mask_sep, \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
.scan_type = { \
.sign = 'u', \
.realbits = (bits), \
.storagebits = 16, \
.shift = (_shift), \
.endianness = IIO_BE, \
}, \
}
#define ADC081S_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0)
#define AD7091R_CONVST_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
#define ADS786X_CHAN(bits) _AD7476_CHAN((bits), 12 - (bits), \
BIT(IIO_CHAN_INFO_RAW))
static const struct ad7476_chip_info ad7476_chip_info_tbl[] = {
[ID_AD7091R] = {
.channel[0] = AD7091R_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.convst_channel[0] = AD7091R_CONVST_CHAN(12),
.convst_channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.reset = ad7091_reset,
},
[ID_AD7276] = {
.channel[0] = AD7940_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7277] = {
.channel[0] = AD7940_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7278] = {
.channel[0] = AD7940_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7466] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7467] = {
.channel[0] = AD7476_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7468] = {
.channel[0] = AD7476_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_AD7495] = {
.channel[0] = AD7476_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
.int_vref_uv = 2500000,
},
[ID_AD7940] = {
.channel[0] = AD7940_CHAN(14),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADC081S] = {
.channel[0] = ADC081S_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADC101S] = {
.channel[0] = ADC081S_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADC121S] = {
.channel[0] = ADC081S_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADS7866] = {
.channel[0] = ADS786X_CHAN(12),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADS7867] = {
.channel[0] = ADS786X_CHAN(10),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
[ID_ADS7868] = {
.channel[0] = ADS786X_CHAN(8),
.channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1),
},
};
static const struct iio_info ad7476_info = {
.read_raw = &ad7476_read_raw,
};
static void ad7476_reg_disable(void *data)
{
struct ad7476_state *st = data;
regulator_disable(st->reg);
}
static int ad7476_probe(struct spi_device *spi)
{
struct ad7476_state *st;
struct iio_dev *indio_dev;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
st->chip_info =
&ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data];
st->reg = devm_regulator_get(&spi->dev, "vcc");
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, ad7476_reg_disable,
st);
if (ret)
return ret;
st->convst_gpio = devm_gpiod_get_optional(&spi->dev,
"adi,conversion-start",
GPIOD_OUT_LOW);
if (IS_ERR(st->convst_gpio))
return PTR_ERR(st->convst_gpio);
spi_set_drvdata(spi, indio_dev);
st->spi = spi;
/* Establish 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->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channel;
indio_dev->num_channels = 2;
indio_dev->info = &ad7476_info;
if (st->convst_gpio)
indio_dev->channels = st->chip_info->convst_channel;
/* Setup default message */
st->xfer.rx_buf = &st->data;
st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8;
spi_message_init(&st->msg);
spi_message_add_tail(&st->xfer, &st->msg);
ret = iio_triggered_buffer_setup(indio_dev, NULL,
&ad7476_trigger_handler, NULL);
if (ret)
goto error_disable_reg;
if (st->chip_info->reset)
st->chip_info->reset(st);
ret = iio_device_register(indio_dev);
if (ret)
goto error_ring_unregister;
return 0;
error_ring_unregister:
iio_triggered_buffer_cleanup(indio_dev);
error_disable_reg:
regulator_disable(st->reg);
return ret;
}
static const struct spi_device_id ad7476_id[] = {
{"ad7091", ID_AD7091R},
{"ad7091r", ID_AD7091R},
{"ad7273", ID_AD7277},
{"ad7274", ID_AD7276},
{"ad7276", ID_AD7276},
{"ad7277", ID_AD7277},
{"ad7278", ID_AD7278},
{"ad7466", ID_AD7466},
{"ad7467", ID_AD7467},
{"ad7468", ID_AD7468},
{"ad7475", ID_AD7466},
{"ad7476", ID_AD7466},
{"ad7476a", ID_AD7466},
{"ad7477", ID_AD7467},
{"ad7477a", ID_AD7467},
{"ad7478", ID_AD7468},
{"ad7478a", ID_AD7468},
{"ad7495", ID_AD7495},
{"ad7910", ID_AD7467},
{"ad7920", ID_AD7466},
{"ad7940", ID_AD7940},
{"adc081s", ID_ADC081S},
{"adc101s", ID_ADC101S},
{"adc121s", ID_ADC121S},
{"ads7866", ID_ADS7866},
{"ads7867", ID_ADS7867},
{"ads7868", ID_ADS7868},
{}
};
MODULE_DEVICE_TABLE(spi, ad7476_id);
static struct spi_driver ad7476_driver = {
.driver = {
.name = "ad7476",
},
.probe = ad7476_probe,
.id_table = ad7476_id,
};
module_spi_driver(ad7476_driver);
MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs");
MODULE_LICENSE("GPL v2");
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