Re: [PATCH v4] iio: adc: New driver for TI ADS7950 chips

[Jonathan Cameron]

On 28/11/16 16:58, David Lechner wrote:
> This adds a new driver for the TI ADS7950 family of ADC chips. These
> communicate using SPI and come in 8/10/12-bit and 4/8/12/16 channel
> varieties.
> 
> Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
Very nice. Applied to the togreg branch of iio.git - initially pushed
out as testing when I next have an internet connection....

thanks,

Jonathan
> ---
> 
> v4 changes:
> * Change spi_async() back to spi_sync(). (I have learned that this is in a
>   threaded interrupt handler, so sleeping is OK.)
> 
> v3 changes:
> 
> * Use spi_async() instead of spi_sync() in ti_ads7950_trigger_handler()
> * Fix scaling in ti_ads7950_read_raw()
> 
> v2 changes:
> 
> * Got rid of XX wildcards - using ADS7950 everywhere
> * Fixed some macro parentheses issues
> * Added TI_ prefix to macros to match ti_ prefixes used elsewhere
> * Added space in rx_buf for holding timestamp
> * Use iio_device_claim_direct_mode() and spi_message_init_with_transfers()
>   helper functions
> * Don't use dev_info() at end of probe
> * Minor spelling and code style fixes
> 
>  drivers/iio/adc/Kconfig      |  13 ++
>  drivers/iio/adc/Makefile     |   1 +
>  drivers/iio/adc/ti-ads7950.c | 490 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 504 insertions(+)
>  create mode 100644 drivers/iio/adc/ti-ads7950.c
> 
> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
> index 6bbee0b..26b32f0 100644
> --- a/drivers/iio/adc/Kconfig
> +++ b/drivers/iio/adc/Kconfig
> @@ -527,6 +527,19 @@ config TI_ADS1015
>  	  This driver can also be built as a module. If so, the module will be
>  	  called ti-ads1015.
>  
> +config TI_ADS7950
> +	tristate "Texas Instruments ADS7950 ADC driver"
> +	depends on SPI
> +	select IIO_BUFFER
> +	select IIO_TRIGGERED_BUFFER
> +	help
> +	  Say yes here to build support for Texas Instruments ADS7950, ADS7951,
> +	  ADS7952, ADS7953, ADS7954, ADS7955, ADS7956, ADS7957, ADS7958, ADS7959.
> +	  ADS7960, ADS7961.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ti-ads7950.
> +
>  config TI_ADS8688
>  	tristate "Texas Instruments ADS8688"
>  	depends on SPI && OF
> diff --git a/drivers/iio/adc/Makefile b/drivers/iio/adc/Makefile
> index 9391217..1966801 100644
> --- a/drivers/iio/adc/Makefile
> +++ b/drivers/iio/adc/Makefile
> @@ -49,6 +49,7 @@ obj-$(CONFIG_TI_ADC12138) += ti-adc12138.o
>  obj-$(CONFIG_TI_ADC128S052) += ti-adc128s052.o
>  obj-$(CONFIG_TI_ADC161S626) += ti-adc161s626.o
>  obj-$(CONFIG_TI_ADS1015) += ti-ads1015.o
> +obj-$(CONFIG_TI_ADS7950) += ti-ads7950.o
>  obj-$(CONFIG_TI_ADS8688) += ti-ads8688.o
>  obj-$(CONFIG_TI_AM335X_ADC) += ti_am335x_adc.o
>  obj-$(CONFIG_TWL4030_MADC) += twl4030-madc.o
> diff --git a/drivers/iio/adc/ti-ads7950.c b/drivers/iio/adc/ti-ads7950.c
> new file mode 100644
> index 0000000..0330361
> --- /dev/null
> +++ b/drivers/iio/adc/ti-ads7950.c
> @@ -0,0 +1,490 @@
> +/*
> + * Texas Instruments ADS7950 SPI ADC driver
> + *
> + * Copyright 2016 David Lechner <david@xxxxxxxxxxxxxx>
> + *
> + * Based on iio/ad7923.c:
> + * Copyright 2011 Analog Devices Inc
> + * Copyright 2012 CS Systemes d'Information
> + *
> + * And also on hwmon/ads79xx.c
> + * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
> + *	Nishanth Menon
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation version 2.
> + *
> + * This program is distributed "as is" WITHOUT ANY WARRANTY of any
> + * kind, whether express or implied; without even the implied warranty
> + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + */
> +
> +#include <linux/bitops.h>
> +#include <linux/device.h>
> +#include <linux/err.h>
> +#include <linux/interrupt.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/slab.h>
> +#include <linux/spi/spi.h>
> +
> +#include <linux/iio/buffer.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger_consumer.h>
> +#include <linux/iio/triggered_buffer.h>
> +
> +#define TI_ADS7950_CR_MANUAL	BIT(12)
> +#define TI_ADS7950_CR_WRITE	BIT(11)
> +#define TI_ADS7950_CR_CHAN(ch)	((ch) << 7)
> +#define TI_ADS7950_CR_RANGE_5V	BIT(6)
> +
> +#define TI_ADS7950_MAX_CHAN	16
> +
> +#define TI_ADS7950_TIMESTAMP_SIZE (sizeof(int64_t) / sizeof(__be16))
> +
> +/* val = value, dec = left shift, bits = number of bits of the mask */
> +#define TI_ADS7950_EXTRACT(val, dec, bits) \
> +	(((val) >> (dec)) & ((1 << (bits)) - 1))
> +
> +struct ti_ads7950_state {
> +	struct spi_device	*spi;
> +	struct spi_transfer	ring_xfer[TI_ADS7950_MAX_CHAN + 2];
> +	struct spi_transfer	scan_single_xfer[3];
> +	struct spi_message	ring_msg;
> +	struct spi_message	scan_single_msg;
> +
> +	struct regulator	*reg;
> +
> +	unsigned int		settings;
> +
> +	/*
> +	 * DMA (thus cache coherency maintenance) requires the
> +	 * transfer buffers to live in their own cache lines.
> +	 */
> +	__be16	rx_buf[TI_ADS7950_MAX_CHAN + TI_ADS7950_TIMESTAMP_SIZE]
> +							____cacheline_aligned;
> +	__be16	tx_buf[TI_ADS7950_MAX_CHAN];
> +};
> +
> +struct ti_ads7950_chip_info {
> +	const struct iio_chan_spec *channels;
> +	unsigned int num_channels;
> +};
> +
> +enum ti_ads7950_id {
> +	TI_ADS7950,
> +	TI_ADS7951,
> +	TI_ADS7952,
> +	TI_ADS7953,
> +	TI_ADS7954,
> +	TI_ADS7955,
> +	TI_ADS7956,
> +	TI_ADS7957,
> +	TI_ADS7958,
> +	TI_ADS7959,
> +	TI_ADS7960,
> +	TI_ADS7961,
> +};
> +
> +#define TI_ADS7950_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,					\
> +	.datasheet_name = "CH##index",				\
> +	.scan_index = index,					\
> +	.scan_type = {						\
> +		.sign = 'u',					\
> +		.realbits = bits,				\
> +		.storagebits = 16,				\
> +		.shift = 12 - (bits),				\
> +		.endianness = IIO_BE,				\
> +	},							\
> +}
> +
> +#define DECLARE_TI_ADS7950_4_CHANNELS(name, bits) \
> +const struct iio_chan_spec name ## _channels[] = { \
> +	TI_ADS7950_V_CHAN(0, bits), \
> +	TI_ADS7950_V_CHAN(1, bits), \
> +	TI_ADS7950_V_CHAN(2, bits), \
> +	TI_ADS7950_V_CHAN(3, bits), \
> +	IIO_CHAN_SOFT_TIMESTAMP(4), \
> +}
> +
> +#define DECLARE_TI_ADS7950_8_CHANNELS(name, bits) \
> +const struct iio_chan_spec name ## _channels[] = { \
> +	TI_ADS7950_V_CHAN(0, bits), \
> +	TI_ADS7950_V_CHAN(1, bits), \
> +	TI_ADS7950_V_CHAN(2, bits), \
> +	TI_ADS7950_V_CHAN(3, bits), \
> +	TI_ADS7950_V_CHAN(4, bits), \
> +	TI_ADS7950_V_CHAN(5, bits), \
> +	TI_ADS7950_V_CHAN(6, bits), \
> +	TI_ADS7950_V_CHAN(7, bits), \
> +	IIO_CHAN_SOFT_TIMESTAMP(8), \
> +}
> +
> +#define DECLARE_TI_ADS7950_12_CHANNELS(name, bits) \
> +const struct iio_chan_spec name ## _channels[] = { \
> +	TI_ADS7950_V_CHAN(0, bits), \
> +	TI_ADS7950_V_CHAN(1, bits), \
> +	TI_ADS7950_V_CHAN(2, bits), \
> +	TI_ADS7950_V_CHAN(3, bits), \
> +	TI_ADS7950_V_CHAN(4, bits), \
> +	TI_ADS7950_V_CHAN(5, bits), \
> +	TI_ADS7950_V_CHAN(6, bits), \
> +	TI_ADS7950_V_CHAN(7, bits), \
> +	TI_ADS7950_V_CHAN(8, bits), \
> +	TI_ADS7950_V_CHAN(9, bits), \
> +	TI_ADS7950_V_CHAN(10, bits), \
> +	TI_ADS7950_V_CHAN(11, bits), \
> +	IIO_CHAN_SOFT_TIMESTAMP(12), \
> +}
> +
> +#define DECLARE_TI_ADS7950_16_CHANNELS(name, bits) \
> +const struct iio_chan_spec name ## _channels[] = { \
> +	TI_ADS7950_V_CHAN(0, bits), \
> +	TI_ADS7950_V_CHAN(1, bits), \
> +	TI_ADS7950_V_CHAN(2, bits), \
> +	TI_ADS7950_V_CHAN(3, bits), \
> +	TI_ADS7950_V_CHAN(4, bits), \
> +	TI_ADS7950_V_CHAN(5, bits), \
> +	TI_ADS7950_V_CHAN(6, bits), \
> +	TI_ADS7950_V_CHAN(7, bits), \
> +	TI_ADS7950_V_CHAN(8, bits), \
> +	TI_ADS7950_V_CHAN(9, bits), \
> +	TI_ADS7950_V_CHAN(10, bits), \
> +	TI_ADS7950_V_CHAN(11, bits), \
> +	TI_ADS7950_V_CHAN(12, bits), \
> +	TI_ADS7950_V_CHAN(13, bits), \
> +	TI_ADS7950_V_CHAN(14, bits), \
> +	TI_ADS7950_V_CHAN(15, bits), \
> +	IIO_CHAN_SOFT_TIMESTAMP(16), \
> +}
> +
> +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7950, 12);
> +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7951, 12);
> +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7952, 12);
> +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7953, 12);
> +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7954, 10);
> +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7955, 10);
> +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7956, 10);
> +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7957, 10);
> +static DECLARE_TI_ADS7950_4_CHANNELS(ti_ads7958, 8);
> +static DECLARE_TI_ADS7950_8_CHANNELS(ti_ads7959, 8);
> +static DECLARE_TI_ADS7950_12_CHANNELS(ti_ads7960, 8);
> +static DECLARE_TI_ADS7950_16_CHANNELS(ti_ads7961, 8);
> +
> +static const struct ti_ads7950_chip_info ti_ads7950_chip_info[] = {
> +	[TI_ADS7950] = {
> +		.channels	= ti_ads7950_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7950_channels),
> +	},
> +	[TI_ADS7951] = {
> +		.channels	= ti_ads7951_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7951_channels),
> +	},
> +	[TI_ADS7952] = {
> +		.channels	= ti_ads7952_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7952_channels),
> +	},
> +	[TI_ADS7953] = {
> +		.channels	= ti_ads7953_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7953_channels),
> +	},
> +	[TI_ADS7954] = {
> +		.channels	= ti_ads7954_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7954_channels),
> +	},
> +	[TI_ADS7955] = {
> +		.channels	= ti_ads7955_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7955_channels),
> +	},
> +	[TI_ADS7956] = {
> +		.channels	= ti_ads7956_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7956_channels),
> +	},
> +	[TI_ADS7957] = {
> +		.channels	= ti_ads7957_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7957_channels),
> +	},
> +	[TI_ADS7958] = {
> +		.channels	= ti_ads7958_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7958_channels),
> +	},
> +	[TI_ADS7959] = {
> +		.channels	= ti_ads7959_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7959_channels),
> +	},
> +	[TI_ADS7960] = {
> +		.channels	= ti_ads7960_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7960_channels),
> +	},
> +	[TI_ADS7961] = {
> +		.channels	= ti_ads7961_channels,
> +		.num_channels	= ARRAY_SIZE(ti_ads7961_channels),
> +	},
> +};
> +
> +/*
> + * ti_ads7950_update_scan_mode() setup the spi transfer buffer for the new
> + * scan mask
> + */
> +static int ti_ads7950_update_scan_mode(struct iio_dev *indio_dev,
> +				       const unsigned long *active_scan_mask)
> +{
> +	struct ti_ads7950_state *st = iio_priv(indio_dev);
> +	int i, cmd, len;
> +
> +	len = 0;
> +	for_each_set_bit(i, active_scan_mask, indio_dev->num_channels) {
> +		cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(i) | st->settings;
> +		st->tx_buf[len++] = cpu_to_be16(cmd);
> +	}
> +
> +	/* Data for the 1st channel is not returned until the 3rd transfer */
> +	len += 2;
> +	for (i = 0; i < len; i++) {
> +		if ((i + 2) < len)
> +			st->ring_xfer[i].tx_buf = &st->tx_buf[i];
> +		if (i >= 2)
> +			st->ring_xfer[i].rx_buf = &st->rx_buf[i - 2];
> +		st->ring_xfer[i].len = 2;
> +		st->ring_xfer[i].cs_change = 1;
> +	}
> +	/* make sure last transfer's cs_change is not set */
> +	st->ring_xfer[len - 1].cs_change = 0;
> +
> +	spi_message_init_with_transfers(&st->ring_msg, st->ring_xfer, len);
> +
> +	return 0;
> +}
> +
> +static irqreturn_t ti_ads7950_trigger_handler(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +	struct ti_ads7950_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	ret = spi_sync(st->spi, &st->ring_msg);
> +	if (ret < 0)
> +		goto out;
> +
> +	iio_push_to_buffers_with_timestamp(indio_dev, st->rx_buf,
> +					   iio_get_time_ns(indio_dev));
> +
> +out:
> +	iio_trigger_notify_done(indio_dev->trig);
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int ti_ads7950_scan_direct(struct ti_ads7950_state *st, unsigned int ch)
> +{
> +	int ret, cmd;
> +
> +	cmd = TI_ADS7950_CR_WRITE | TI_ADS7950_CR_CHAN(ch) | st->settings;
> +	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 ti_ads7950_get_range(struct ti_ads7950_state *st)
> +{
> +	int vref;
> +
> +	vref = regulator_get_voltage(st->reg);
> +	if (vref < 0)
> +		return vref;
> +
> +	vref /= 1000;
> +
> +	if (st->settings & TI_ADS7950_CR_RANGE_5V)
> +		vref *= 2;
> +
> +	return vref;
> +}
> +
> +static int ti_ads7950_read_raw(struct iio_dev *indio_dev,
> +			       struct iio_chan_spec const *chan,
> +			       int *val, int *val2, long m)
> +{
> +	struct ti_ads7950_state *st = iio_priv(indio_dev);
> +	int ret;
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_RAW:
> +
> +		ret = iio_device_claim_direct_mode(indio_dev);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = ti_ads7950_scan_direct(st, chan->address);
> +		iio_device_release_direct_mode(indio_dev);
> +		if (ret < 0)
> +			return ret;
> +
> +		if (chan->address != TI_ADS7950_EXTRACT(ret, 12, 4))
> +			return -EIO;
> +
> +		*val = TI_ADS7950_EXTRACT(ret, chan->scan_type.shift,
> +					  chan->scan_type.realbits);
> +
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		ret = ti_ads7950_get_range(st);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = ret;
> +		*val2 = (1 << chan->scan_type.realbits) - 1;
> +
> +		return IIO_VAL_FRACTIONAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info ti_ads7950_info = {
> +	.read_raw		= &ti_ads7950_read_raw,
> +	.update_scan_mode	= ti_ads7950_update_scan_mode,
> +	.driver_module		= THIS_MODULE,
> +};
> +
> +static int ti_ads7950_probe(struct spi_device *spi)
> +{
> +	struct ti_ads7950_state *st;
> +	struct iio_dev *indio_dev;
> +	const struct ti_ads7950_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);
> +
> +	spi_set_drvdata(spi, indio_dev);
> +
> +	st->spi = spi;
> +	st->settings = TI_ADS7950_CR_MANUAL | TI_ADS7950_CR_RANGE_5V;
> +
> +	info = &ti_ads7950_chip_info[spi_get_device_id(spi)->driver_data];
> +
> +	indio_dev->name = spi_get_device_id(spi)->name;
> +	indio_dev->dev.parent = &spi->dev;
> +	indio_dev->modes = INDIO_DIRECT_MODE;
> +	indio_dev->channels = info->channels;
> +	indio_dev->num_channels = info->num_channels;
> +	indio_dev->info = &ti_ads7950_info;
> +
> +	/*
> +	 * Setup default message. The sample is read at the end of the first
> +	 * transfer, then it takes one full cycle to convert the sample and one
> +	 * more cycle to send the value. The conversion process is driven by
> +	 * the SPI clock, which is why we have 3 transfers. The middle one is
> +	 * just dummy data sent while the chip is converting the sample that
> +	 * was read at the end of the first transfer.
> +	 */
> +
> +	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].tx_buf = &st->tx_buf[0];
> +	st->scan_single_xfer[1].len = 2;
> +	st->scan_single_xfer[1].cs_change = 1;
> +	st->scan_single_xfer[2].rx_buf = &st->rx_buf[0];
> +	st->scan_single_xfer[2].len = 2;
> +
> +	spi_message_init_with_transfers(&st->scan_single_msg,
> +					st->scan_single_xfer, 3);
> +
> +	st->reg = devm_regulator_get(&spi->dev, "refin");
> +	if (IS_ERR(st->reg)) {
> +		dev_err(&spi->dev, "Failed get get regulator \"refin\"\n");
> +		return PTR_ERR(st->reg);
> +	}
> +
> +	ret = regulator_enable(st->reg);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to enable regulator \"refin\"\n");
> +		return ret;
> +	}
> +
> +	ret = iio_triggered_buffer_setup(indio_dev, NULL,
> +					 &ti_ads7950_trigger_handler, NULL);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to setup triggered buffer\n");
> +		goto error_disable_reg;
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret) {
> +		dev_err(&spi->dev, "Failed to register iio device\n");
> +		goto error_cleanup_ring;
> +	}
> +
> +	return 0;
> +
> +error_cleanup_ring:
> +	iio_triggered_buffer_cleanup(indio_dev);
> +error_disable_reg:
> +	regulator_disable(st->reg);
> +
> +	return ret;
> +}
> +
> +static int ti_ads7950_remove(struct spi_device *spi)
> +{
> +	struct iio_dev *indio_dev = spi_get_drvdata(spi);
> +	struct ti_ads7950_state *st = iio_priv(indio_dev);
> +
> +	iio_device_unregister(indio_dev);
> +	iio_triggered_buffer_cleanup(indio_dev);
> +	regulator_disable(st->reg);
> +
> +	return 0;
> +}
> +
> +static const struct spi_device_id ti_ads7950_id[] = {
> +	{"ti-ads7950", TI_ADS7950},
> +	{"ti-ads7951", TI_ADS7951},
> +	{"ti-ads7952", TI_ADS7952},
> +	{"ti-ads7953", TI_ADS7953},
> +	{"ti-ads7954", TI_ADS7954},
> +	{"ti-ads7955", TI_ADS7955},
> +	{"ti-ads7956", TI_ADS7956},
> +	{"ti-ads7957", TI_ADS7957},
> +	{"ti-ads7958", TI_ADS7958},
> +	{"ti-ads7959", TI_ADS7959},
> +	{"ti-ads7960", TI_ADS7960},
> +	{"ti-ads7961", TI_ADS7961},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(spi, ti_ads7950_id);
> +
> +static struct spi_driver ti_ads7950_driver = {
> +	.driver = {
> +		.name	= "ti-ads7950",
> +	},
> +	.probe		= ti_ads7950_probe,
> +	.remove		= ti_ads7950_remove,
> +	.id_table	= ti_ads7950_id,
> +};
> +module_spi_driver(ti_ads7950_driver);
> +
> +MODULE_AUTHOR("David Lechner <david@xxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("TI TI_ADS7950 ADC");
> +MODULE_LICENSE("GPL v2");
>