Re: [PATCH] IIO: DDS: AD9832 / AD9835 driver

[Jonathan Cameron <jic23@cam.ac.uk>]

On 02/08/11 15:40, michael.hennerich@analog.com wrote:
> From: Michael Hennerich <michael.hennerich@analog.com>
> 
> This is a complete rewrite of the AD9832/35 driver.
> Purpose was to move this driver to the recently
> created API for such devices.
Nice driver.  Three observations inline.  Fine with me to
merge as is.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
> ---
>  drivers/staging/iio/dds/Kconfig  |    5 +-
>  drivers/staging/iio/dds/ad9832.c |  488 ++++++++++++++++++++++++--------------
>  drivers/staging/iio/dds/ad9832.h |  138 +++++++++++
>  3 files changed, 447 insertions(+), 184 deletions(-)
>  create mode 100644 drivers/staging/iio/dds/ad9832.h
> 
> diff --git a/drivers/staging/iio/dds/Kconfig b/drivers/staging/iio/dds/Kconfig
> index a047da6..06b6f3a 100644
> --- a/drivers/staging/iio/dds/Kconfig
> +++ b/drivers/staging/iio/dds/Kconfig
> @@ -15,7 +15,10 @@ config AD9832
>  	depends on SPI
>  	help
>  	  Say yes here to build support for Analog Devices DDS chip
> -	  ad9832 and ad9835, provides direct access via sysfs.
> +	  AD9832 and AD9835, provides direct access via sysfs.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ad9832.
>  
>  config AD9834
>  	tristate "Analog Devices ad9833/4/ driver"
> diff --git a/drivers/staging/iio/dds/ad9832.c b/drivers/staging/iio/dds/ad9832.c
> index e911893..78a46c5 100644
> --- a/drivers/staging/iio/dds/ad9832.c
> +++ b/drivers/staging/iio/dds/ad9832.c
> @@ -1,228 +1,338 @@
>  /*
> - * Driver for ADI Direct Digital Synthesis ad9832
> + * AD9832 SPI DDS driver
>   *
> - * Copyright (c) 2010 Analog Devices Inc.
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU General Public License version 2 as
> - * published by the Free Software Foundation.
> + * Copyright 2011 Analog Devices Inc.
>   *
> + * Licensed under the GPL-2.
>   */
> -#include <linux/types.h>
> -#include <linux/mutex.h>
> +
>  #include <linux/device.h>
> -#include <linux/spi/spi.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 <asm/div64.h>
>  
>  #include "../iio.h"
>  #include "../sysfs.h"
> +#include "dds.h"
>  
> -#define DRV_NAME "ad9832"
> -
> -#define value_mask (u16)0xf000
> -#define cmd_shift 12
> -#define add_shift 8
> -#define AD9832_SYNC (1 << 13)
> -#define AD9832_SELSRC (1 << 12)
> -#define AD9832_SLEEP (1 << 13)
> -#define AD9832_RESET (1 << 12)
> -#define AD9832_CLR (1 << 11)
> -
> -#define ADD_FREQ0LL 0x0
> -#define ADD_FREQ0HL 0x1
> -#define ADD_FREQ0LM 0x2
> -#define ADD_FREQ0HM 0x3
> -#define ADD_FREQ1LL 0x4
> -#define ADD_FREQ1HL 0x5
> -#define ADD_FREQ1LM 0x6
> -#define ADD_FREQ1HM 0x7
> -#define ADD_PHASE0L 0x8
> -#define ADD_PHASE0H 0x9
> -#define ADD_PHASE1L 0xa
> -#define ADD_PHASE1H 0xb
> -#define ADD_PHASE2L 0xc
> -#define ADD_PHASE2H 0xd
> -#define ADD_PHASE3L 0xe
> -#define ADD_PHASE3H 0xf
> -
> -#define CMD_PHA8BITSW 0x1
> -#define CMD_PHA16BITSW 0x0
> -#define CMD_FRE8BITSW 0x3
> -#define CMD_FRE16BITSW 0x2
> -#define CMD_SELBITSCTL 0x6
> -
> -struct ad9832_setting {
> -	u16 freq0[4];
> -	u16 freq1[4];
> -	u16 phase0[2];
> -	u16 phase1[2];
> -	u16 phase2[2];
> -	u16 phase3[2];
> -};
> +#include "ad9832.h"
>  
> -struct ad9832_state {
> -	struct mutex lock;
> -	struct iio_dev *idev;
> -	struct spi_device *sdev;
> -};
> -
> -static ssize_t ad9832_set_parameter(struct device *dev,
> -					struct device_attribute *attr,
> -					const char *buf,
> -					size_t len)
> +static unsigned long ad9832_calc_freqreg(unsigned long mclk, unsigned long fout)
>  {
> -	struct spi_message msg;
> -	struct spi_transfer xfer;
> -	int ret;
> -	struct ad9832_setting config;
> -	struct iio_dev *idev = dev_get_drvdata(dev);
> -	struct ad9832_state *st = idev->dev_data;
> -
> -	config.freq0[0] = (CMD_FRE8BITSW << add_shift | ADD_FREQ0LL << add_shift | buf[0]);
> -	config.freq0[1] = (CMD_FRE16BITSW << add_shift | ADD_FREQ0HL << add_shift | buf[1]);
> -	config.freq0[2] = (CMD_FRE8BITSW << add_shift | ADD_FREQ0LM << add_shift | buf[2]);
> -	config.freq0[3] = (CMD_FRE16BITSW << add_shift | ADD_FREQ0HM << add_shift | buf[3]);
> -	config.freq1[0] = (CMD_FRE8BITSW << add_shift | ADD_FREQ1LL << add_shift | buf[4]);
> -	config.freq1[1] = (CMD_FRE16BITSW << add_shift | ADD_FREQ1HL << add_shift | buf[5]);
> -	config.freq1[2] = (CMD_FRE8BITSW << add_shift | ADD_FREQ1LM << add_shift | buf[6]);
> -	config.freq1[3] = (CMD_FRE16BITSW << add_shift | ADD_FREQ1HM << add_shift | buf[7]);
> -
> -	config.phase0[0] = (CMD_PHA8BITSW << add_shift | ADD_PHASE0L << add_shift | buf[9]);
> -	config.phase0[1] = (CMD_PHA16BITSW << add_shift | ADD_PHASE0H << add_shift | buf[10]);
> -	config.phase1[0] = (CMD_PHA8BITSW << add_shift | ADD_PHASE1L << add_shift | buf[11]);
> -	config.phase1[1] = (CMD_PHA16BITSW << add_shift | ADD_PHASE1H << add_shift | buf[12]);
> -	config.phase2[0] = (CMD_PHA8BITSW << add_shift | ADD_PHASE2L << add_shift | buf[13]);
> -	config.phase2[1] = (CMD_PHA16BITSW << add_shift | ADD_PHASE2H << add_shift | buf[14]);
> -	config.phase3[0] = (CMD_PHA8BITSW << add_shift | ADD_PHASE3L << add_shift | buf[15]);
> -	config.phase3[1] = (CMD_PHA16BITSW << add_shift | ADD_PHASE3H << add_shift | buf[16]);
> -
> -	xfer.len = 2 * len;
> -	xfer.tx_buf = &config;
> -	mutex_lock(&st->lock);
> -
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfer, &msg);
> -	ret = spi_sync(st->sdev, &msg);
> -	if (ret)
> -		goto error_ret;
> -error_ret:
> -	mutex_unlock(&st->lock);
> +	unsigned long long freqreg = (u64) fout *
> +				     (u64) ((u64) 1L << AD9832_FREQ_BITS);
> +	do_div(freqreg, mclk);
> +	return freqreg;
> +}
>  
> -	return ret ? ret : len;
> +static int ad9832_write_frequency(struct ad9832_state *st,
> +				  unsigned addr, unsigned long fout)
> +{
> +	unsigned long regval;
> +
> +	if (fout > (st->mclk / 2))
> +		return -EINVAL;
> +
> +	regval = ad9832_calc_freqreg(st->mclk, fout);
> +
> +	st->freq_data[0] = cpu_to_be16((AD9832_CMD_FRE8BITSW << CMD_SHIFT) |
> +					(addr << ADD_SHIFT) |
> +					((regval >> 24) & 0xFF));
> +	st->freq_data[1] = cpu_to_be16((AD9832_CMD_FRE16BITSW << CMD_SHIFT) |
> +					((addr - 1) << ADD_SHIFT) |
> +					((regval >> 16) & 0xFF));
> +	st->freq_data[2] = cpu_to_be16((AD9832_CMD_FRE8BITSW << CMD_SHIFT) |
> +					((addr - 2) << ADD_SHIFT) |
> +					((regval >> 8) & 0xFF));
> +	st->freq_data[3] = cpu_to_be16((AD9832_CMD_FRE16BITSW << CMD_SHIFT) |
> +					((addr - 3) << ADD_SHIFT) |
> +					((regval >> 0) & 0xFF));
> +
> +	return spi_sync(st->spi, &st->freq_msg);;
>  }
>  
> -static IIO_DEVICE_ATTR(dds, S_IWUSR, NULL, ad9832_set_parameter, 0);
> +static int ad9832_write_phase(struct ad9832_state *st,
> +				  unsigned long addr, unsigned long phase)
> +{
> +	if (phase > (1 << AD9832_PHASE_BITS))
> +		return -EINVAL;
>  
> -static struct attribute *ad9832_attributes[] = {
> -	&iio_dev_attr_dds.dev_attr.attr,
> -	NULL,
> -};
> +	st->phase_data[0] = cpu_to_be16((AD9832_CMD_PHA8BITSW << CMD_SHIFT) |
> +					(addr << ADD_SHIFT) |
> +					((phase >> 8) & 0xFF));
> +	st->phase_data[1] = cpu_to_be16((AD9832_CMD_PHA16BITSW << CMD_SHIFT) |
> +					((addr - 1) << ADD_SHIFT) |
> +					(phase & 0xFF));
>  
> -static const struct attribute_group ad9832_attribute_group = {
> -	.name = DRV_NAME,
> -	.attrs = ad9832_attributes,
> -};
> +	return spi_sync(st->spi, &st->phase_msg);
> +}
>  
> -static void ad9832_init(struct ad9832_state *st)
> +static ssize_t ad9832_write(struct device *dev,
> +		struct device_attribute *attr,
> +		const char *buf,
> +		size_t len)
>  {
> -	struct spi_message msg;
> -	struct spi_transfer xfer;
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad9832_state *st = dev_info->dev_data;
> +	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
>  	int ret;
> -	u16 config = 0;
> -
> -	config = 0x3 << 14 | AD9832_SLEEP | AD9832_RESET | AD9832_CLR;
> +	long val;
>  
> -	mutex_lock(&st->lock);
> -
> -	xfer.len = 2;
> -	xfer.tx_buf = &config;
> -
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfer, &msg);
> -	ret = spi_sync(st->sdev, &msg);
> +	ret = strict_strtoul(buf, 10, &val);
>  	if (ret)
>  		goto error_ret;
>  
> -	config = 0x2 << 14 | AD9832_SYNC | AD9832_SELSRC;
> -	xfer.len = 2;
> -	xfer.tx_buf = &config;
> +	mutex_lock(&dev_info->mlock);
> +	switch (this_attr->address) {
> +	case AD9832_FREQ0HM:
> +	case AD9832_FREQ1HM:
> +		ret = ad9832_write_frequency(st, this_attr->address, val);
> +		break;
> +	case AD9832_PHASE0H:
> +	case AD9832_PHASE1H:
> +	case AD9832_PHASE2H:
> +	case AD9832_PHASE3H:
> +		ret = ad9832_write_phase(st, this_attr->address, val);
> +		break;
> +	case AD9832_PINCTRL_EN:
> +		if (val)
> +			st->ctrl_ss &= ~AD9832_SELSRC;
> +		else
> +			st->ctrl_ss |= AD9832_SELSRC;
> +		st->data = cpu_to_be16((AD9832_CMD_SYNCSELSRC << CMD_SHIFT) |
> +					st->ctrl_ss);
> +		ret = spi_sync(st->spi, &st->msg);
> +		break;
> +	case AD9832_FREQ_SYM:
> +		if (val == 1)
> +			st->ctrl_fp |= AD9832_FREQ;
> +		else if (val == 0)
> +			st->ctrl_fp &= ~AD9832_FREQ;
> +		else {
> +			ret = -EINVAL;
> +			break;
> +		}
> +		st->data = cpu_to_be16((AD9832_CMD_FPSELECT << CMD_SHIFT) |
> +					st->ctrl_fp);
> +		ret = spi_sync(st->spi, &st->msg);
> +		break;
> +	case AD9832_PHASE_SYM:
> +		if (val < 0 || val > 3) {
> +			ret = -EINVAL;
> +			break;
> +		}
> +
> +		st->ctrl_fp &= ~AD9832_PHASE(3);
> +		st->ctrl_fp |= AD9832_PHASE(val);
> +
> +		st->data = cpu_to_be16((AD9832_CMD_FPSELECT << CMD_SHIFT) |
> +					st->ctrl_fp);
> +		ret = spi_sync(st->spi, &st->msg);
> +		break;
> +	case AD9832_OUTPUT_EN:
> +		if (val)
> +			st->ctrl_src &= ~(AD9832_RESET | AD9832_SLEEP |
> +					AD9832_CLR);
> +		else
> +			st->ctrl_src |= AD9832_RESET;
> +
> +		st->data = cpu_to_be16((AD9832_CMD_SLEEPRESCLR << CMD_SHIFT) |
> +					st->ctrl_src);
> +		ret = spi_sync(st->spi, &st->msg);
> +		break;
> +	default:
> +		ret = -ENODEV;
> +	}
> +	mutex_unlock(&dev_info->mlock);
>  
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfer, &msg);
> -	ret = spi_sync(st->sdev, &msg);
> -	if (ret)
> -		goto error_ret;
> +error_ret:
> +	return ret ? ret : len;
> +}
>  
> -	config = CMD_SELBITSCTL << cmd_shift;
> -	xfer.len = 2;
> -	xfer.tx_buf = &config;
> +static ssize_t ad9832_show_name(struct device *dev,
> +				 struct device_attribute *attr,
> +				 char *buf)
> +{
> +	struct iio_dev *dev_info = dev_get_drvdata(dev);
> +	struct ad9832_state *st = iio_dev_get_devdata(dev_info);
>  
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfer, &msg);
> -	ret = spi_sync(st->sdev, &msg);
> -	if (ret)
> -		goto error_ret;
> +	return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
> +}
> +static IIO_DEVICE_ATTR(name, S_IRUGO, ad9832_show_name, NULL, 0);
>  
> -	config = 0x3 << 14;
> +/**
> + * see dds.h for further information
> + */
>  
> -	xfer.len = 2;
> -	xfer.tx_buf = &config;
> +static IIO_DEV_ATTR_FREQ(0, 0, S_IWUSR, NULL, ad9832_write, AD9832_FREQ0HM);
> +static IIO_DEV_ATTR_FREQ(0, 1, S_IWUSR, NULL, ad9832_write, AD9832_FREQ1HM);
> +static IIO_DEV_ATTR_FREQSYMBOL(0, S_IWUSR, NULL, ad9832_write, AD9832_FREQ_SYM);
> +static IIO_CONST_ATTR_FREQ_SCALE(0, "1"); /* 1Hz */
>  
> -	spi_message_init(&msg);
> -	spi_message_add_tail(&xfer, &msg);
> -	ret = spi_sync(st->sdev, &msg);
> -	if (ret)
> -		goto error_ret;
> -error_ret:
> -	mutex_unlock(&st->lock);
> +static IIO_DEV_ATTR_PHASE(0, 0, S_IWUSR, NULL, ad9832_write, AD9832_PHASE0H);
> +static IIO_DEV_ATTR_PHASE(0, 1, S_IWUSR, NULL, ad9832_write, AD9832_PHASE1H);
> +static IIO_DEV_ATTR_PHASE(0, 2, S_IWUSR, NULL, ad9832_write, AD9832_PHASE2H);
> +static IIO_DEV_ATTR_PHASE(0, 3, S_IWUSR, NULL, ad9832_write, AD9832_PHASE3H);
> +static IIO_DEV_ATTR_PHASESYMBOL(0, S_IWUSR, NULL,
> +				ad9832_write, AD9832_PHASE_SYM);
> +static IIO_CONST_ATTR_PHASE_SCALE(0, "0.0015339808"); /* 2PI/2^12 rad*/
>  
> +static IIO_DEV_ATTR_PINCONTROL_EN(0, S_IWUSR, NULL,
> +				ad9832_write, AD9832_PINCTRL_EN);
> +static IIO_DEV_ATTR_OUT_ENABLE(0, S_IWUSR, NULL,
> +				ad9832_write, AD9832_OUTPUT_EN);
>  
> +static struct attribute *ad9832_attributes[] = {
> +	&iio_dev_attr_dds0_freq0.dev_attr.attr,
> +	&iio_dev_attr_dds0_freq1.dev_attr.attr,
> +	&iio_const_attr_dds0_freq_scale.dev_attr.attr,
> +	&iio_dev_attr_dds0_phase0.dev_attr.attr,
> +	&iio_dev_attr_dds0_phase1.dev_attr.attr,
> +	&iio_dev_attr_dds0_phase2.dev_attr.attr,
> +	&iio_dev_attr_dds0_phase3.dev_attr.attr,
> +	&iio_const_attr_dds0_phase_scale.dev_attr.attr,
> +	&iio_dev_attr_dds0_pincontrol_en.dev_attr.attr,
> +	&iio_dev_attr_dds0_freqsymbol.dev_attr.attr,
> +	&iio_dev_attr_dds0_phasesymbol.dev_attr.attr,
> +	&iio_dev_attr_dds0_out_enable.dev_attr.attr,
> +	&iio_dev_attr_name.dev_attr.attr,
> +	NULL,
> +};
>  
> -}
> +static const struct attribute_group ad9832_attribute_group = {
> +	.attrs = ad9832_attributes,
> +};
>  
>  static int __devinit ad9832_probe(struct spi_device *spi)
>  {
> +	struct ad9832_platform_data *pdata = spi->dev.platform_data;
>  	struct ad9832_state *st;
> -	int ret = 0;
> +	int ret;
> +
> +	if (!pdata) {
> +		dev_dbg(&spi->dev, "no platform data?\n");
> +		return -ENODEV;
> +	}
>  
>  	st = kzalloc(sizeof(*st), GFP_KERNEL);
>  	if (st == NULL) {
>  		ret = -ENOMEM;
>  		goto error_ret;
>  	}
> +
> +	st->reg = regulator_get(&spi->dev, "vcc");
> +	if (!IS_ERR(st->reg)) {
> +		ret = regulator_enable(st->reg);
> +		if (ret)
> +			goto error_put_reg;
> +	}
> +
> +	st->mclk = pdata->mclk;
> +
>  	spi_set_drvdata(spi, st);
>  
> -	mutex_init(&st->lock);
> -	st->sdev = spi;
> +	st->spi = spi;

devid isn't used anywhere so should probably get rid of it
until it is used.
> +	st->devid = spi_get_device_id(spi)->driver_data;
>  
> -	st->idev = iio_allocate_device();
> -	if (st->idev == NULL) {
> +	st->indio_dev = iio_allocate_device();
> +	if (st->indio_dev == NULL) {
>  		ret = -ENOMEM;
> -		goto error_free_st;
> +		goto error_disable_reg;
>  	}
> -	st->idev->dev.parent = &spi->dev;
> -	st->idev->num_interrupt_lines = 0;
> -	st->idev->event_attrs = NULL;
>  
> -	st->idev->attrs = &ad9832_attribute_group;
> -	st->idev->dev_data = (void *)(st);
> -	st->idev->driver_module = THIS_MODULE;
> -	st->idev->modes = INDIO_DIRECT_MODE;
> +	st->indio_dev->dev.parent = &spi->dev;
> +	st->indio_dev->attrs = &ad9832_attribute_group;
> +	st->indio_dev->dev_data = (void *) st;
> +	st->indio_dev->driver_module = THIS_MODULE;
> +	st->indio_dev->modes = INDIO_DIRECT_MODE;
> +
> +	/* Setup default messages */
> +
> +	st->xfer.tx_buf = &st->data;
> +	st->xfer.len = 2;
> +
> +	spi_message_init(&st->msg);
> +	spi_message_add_tail(&st->xfer, &st->msg);
> +
> +	st->freq_xfer[0].tx_buf = &st->freq_data[0];
> +	st->freq_xfer[0].len = 2;
> +	st->freq_xfer[0].cs_change = 1;
> +	st->freq_xfer[1].tx_buf = &st->freq_data[1];
> +	st->freq_xfer[1].len = 2;
> +	st->freq_xfer[1].cs_change = 1;
> +	st->freq_xfer[2].tx_buf = &st->freq_data[2];
> +	st->freq_xfer[2].len = 2;
> +	st->freq_xfer[2].cs_change = 1;
> +	st->freq_xfer[3].tx_buf = &st->freq_data[3];
> +	st->freq_xfer[3].len = 2;
> +
> +	spi_message_init(&st->freq_msg);
> +	spi_message_add_tail(&st->freq_xfer[0], &st->freq_msg);
> +	spi_message_add_tail(&st->freq_xfer[1], &st->freq_msg);
> +	spi_message_add_tail(&st->freq_xfer[2], &st->freq_msg);
> +	spi_message_add_tail(&st->freq_xfer[3], &st->freq_msg);
> +
> +	st->phase_xfer[0].tx_buf = &st->phase_data[0];
> +	st->phase_xfer[0].len = 2;
> +	st->phase_xfer[0].cs_change = 1;
> +	st->phase_xfer[1].tx_buf = &st->phase_data[1];
> +	st->phase_xfer[1].len = 2;
> +
> +	spi_message_init(&st->phase_msg);
> +	spi_message_add_tail(&st->phase_xfer[0], &st->phase_msg);
> +	spi_message_add_tail(&st->phase_xfer[1], &st->phase_msg);
> +
> +	st->ctrl_src = AD9832_SLEEP | AD9832_RESET | AD9832_CLR;
> +	st->data = cpu_to_be16((AD9832_CMD_SLEEPRESCLR << CMD_SHIFT) |
> +					st->ctrl_src);
> +	ret = spi_sync(st->spi, &st->msg);
> +	if (ret) {
> +		dev_err(&spi->dev, "device init failed\n");
> +		goto error_free_device;
> +	}
>  
> -	ret = iio_device_register(st->idev);
> +	ret = ad9832_write_frequency(st, AD9832_FREQ0HM, pdata->freq0);
>  	if (ret)
> -		goto error_free_dev;
> -	spi->max_speed_hz = 2000000;
> -	spi->mode = SPI_MODE_3;
> -	spi->bits_per_word = 16;
> -	spi_setup(spi);
> -	ad9832_init(st);
> +		goto error_free_device;
> +
> +	ret = ad9832_write_frequency(st, AD9832_FREQ1HM, pdata->freq1);
> +	if (ret)
> +		goto error_free_device;
> +
> +	ret = ad9832_write_phase(st, AD9832_PHASE0H, pdata->phase0);
> +	if (ret)
> +		goto error_free_device;
> +
> +	ret = ad9832_write_phase(st, AD9832_PHASE1H, pdata->phase1);
> +	if (ret)
> +		goto error_free_device;
> +
> +	ret = ad9832_write_phase(st, AD9832_PHASE2H, pdata->phase2);
> +	if (ret)
> +		goto error_free_device;
> +
> +	ret = ad9832_write_phase(st, AD9832_PHASE3H, pdata->phase3);
> +	if (ret)
> +		goto error_free_device;
> +
> +	ret = iio_device_register(st->indio_dev);
> +	if (ret)
> +		goto error_free_device;
> +
>  	return 0;
>  
> -error_free_dev:
> -	iio_free_device(st->idev);
> -error_free_st:
> +error_free_device:
> +	iio_free_device(st->indio_dev);
> +error_disable_reg:
> +	if (!IS_ERR(st->reg))
> +		regulator_disable(st->reg);
> +error_put_reg:
> +	if (!IS_ERR(st->reg))
> +		regulator_put(st->reg);
>  	kfree(st);
>  error_ret:
>  	return ret;
> @@ -232,33 +342,45 @@ static int __devexit ad9832_remove(struct spi_device *spi)
>  {
>  	struct ad9832_state *st = spi_get_drvdata(spi);
>  
> -	iio_device_unregister(st->idev);
> +	iio_device_unregister(st->indio_dev);
> +	if (!IS_ERR(st->reg)) {
> +		regulator_disable(st->reg);
> +		regulator_put(st->reg);
> +	}
>  	kfree(st);
> -
>  	return 0;
>  }
>  
> +static const struct spi_device_id ad9832_id[] = {
> +	{"ad9832", ID_AD9832},
> +	{"ad9835", ID_AD9835},
> +	{}
> +};
> +
>  static struct spi_driver ad9832_driver = {
>  	.driver = {
> -		.name = DRV_NAME,
> -		.owner = THIS_MODULE,
> +		.name	= "ad9832",
> +		.bus	= &spi_bus_type,
> +		.owner	= THIS_MODULE,
>  	},
> -	.probe = ad9832_probe,
> -	.remove = __devexit_p(ad9832_remove),
> +	.probe		= ad9832_probe,
> +	.remove		= __devexit_p(ad9832_remove),
> +	.id_table	= ad9832_id,
>  };
>  
> -static __init int ad9832_spi_init(void)
> +static int __init ad9832_init(void)
>  {
>  	return spi_register_driver(&ad9832_driver);
>  }
> -module_init(ad9832_spi_init);
> +module_init(ad9832_init);
>  
> -static __exit void ad9832_spi_exit(void)
> +static void __exit ad9832_exit(void)
>  {
>  	spi_unregister_driver(&ad9832_driver);
>  }
> -module_exit(ad9832_spi_exit);
> +module_exit(ad9832_exit);
>  
> -MODULE_AUTHOR("Cliff Cai");
> -MODULE_DESCRIPTION("Analog Devices ad9832 driver");
> +MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
> +MODULE_DESCRIPTION("Analog Devices AD9832/AD9835 DDS");
>  MODULE_LICENSE("GPL v2");
> +MODULE_ALIAS("spi:ad9832");
> diff --git a/drivers/staging/iio/dds/ad9832.h b/drivers/staging/iio/dds/ad9832.h
> new file mode 100644
> index 0000000..6a0a749
> --- /dev/null
> +++ b/drivers/staging/iio/dds/ad9832.h
> @@ -0,0 +1,138 @@
> +/*
> + * AD9832 SPI DDS driver
> + *
> + * Copyright 2011 Analog Devices Inc.
> + *
> + * Licensed under the GPL-2 or later.
> + */
> +#ifndef IIO_DDS_AD9832_H_
> +#define IIO_DDS_AD9832_H_
> +
> +/* Registers */
> +
> +#define AD9832_FREQ0LL 0x0
> +#define AD9832_FREQ0HL 0x1
> +#define AD9832_FREQ0LM 0x2
> +#define AD9832_FREQ0HM 0x3
> +#define AD9832_FREQ1LL 0x4
> +#define AD9832_FREQ1HL 0x5
> +#define AD9832_FREQ1LM 0x6
> +#define AD9832_FREQ1HM 0x7
> +#define AD9832_PHASE0L 0x8
> +#define AD9832_PHASE0H 0x9
> +#define AD9832_PHASE1L 0xA
> +#define AD9832_PHASE1H 0xB
> +#define AD9832_PHASE2L 0xC
> +#define AD9832_PHASE2H 0xD
> +#define AD9832_PHASE3L 0xE
> +#define AD9832_PHASE3H 0xF
> +
> +/* None Registers */
None ?
> +
> +#define AD9832_PHASE_SYM	0x10
> +#define AD9832_FREQ_SYM		0x11
> +#define AD9832_PINCTRL_EN	0x12
> +#define AD9832_OUTPUT_EN	0x13
> +
> +/* Command Control Bits */
> +
> +#define AD9832_CMD_PHA8BITSW	0x1
> +#define AD9832_CMD_PHA16BITSW	0x0
> +#define AD9832_CMD_FRE8BITSW	0x3
> +#define AD9832_CMD_FRE16BITSW	0x2
> +#define AD9832_CMD_FPSELECT	0x6
> +#define AD9832_CMD_SYNCSELSRC	0x8
> +#define AD9832_CMD_SLEEPRESCLR	0xC
> +
> +#define AD9832_FREQ	(1 << 11)
> +#define AD9832_PHASE(x)	(((x) & 3) << 9)
> +#define AD9832_SYNC	(1 << 13)
> +#define AD9832_SELSRC	(1 << 12)
> +#define AD9832_SLEEP	(1 << 13)
> +#define AD9832_RESET	(1 << 12)
> +#define AD9832_CLR	(1 << 11)
> +#define CMD_SHIFT	12
> +#define ADD_SHIFT	8
> +#define AD9832_FREQ_BITS	32
> +#define AD9832_PHASE_BITS	12
> +#define RES_MASK(bits)	((1 << (bits)) - 1)
> +
> +/**
> + * struct ad9832_state - driver instance specific data
> + * @indio_dev:		the industrial I/O device
> + * @spi:		spi_device
> + * @reg:		supply regulator
> + * @mclk:		external master clock
> + * @ctrl_fp:		cached frequency/phase control word
> + * @ctrl_ss:		cached sync/selsrc control word
> + * @ctrl_src:		cached sleep/reset/clr word
> + * @xfer:		default spi transfer
> + * @msg:		default spi message
> + * @freq_xfer:		tuning word spi transfer
> + * @freq_msg:		tuning word spi message
> + * @phase_xfer:		tuning word spi transfer
> + * @phase_msg:		tuning word spi message
> + * @data:		spi transmit buffer
> + * @phase_data:		tuning word spi transmit buffer
> + * @freq_data:		tuning word spi transmit buffer
> + */
> +
> +struct ad9832_state {
> +	struct iio_dev			*indio_dev;
> +	struct spi_device		*spi;
> +	struct regulator		*reg;
> +	unsigned int			mclk;
> +	unsigned short			ctrl_fp;
> +	unsigned short			ctrl_ss;
> +	unsigned short			ctrl_src;
> +	unsigned short			devid;
> +	struct spi_transfer		xfer;
> +	struct spi_message		msg;
> +	struct spi_transfer		freq_xfer[4];
> +	struct spi_message		freq_msg;
> +	struct spi_transfer		phase_xfer[2];
> +	struct spi_message		phase_msg;
> +	/*
> +	 * DMA (thus cache coherency maintenance) requires the
> +	 * transfer buffers to live in their own cache lines.
> +	 */
Can't see it making any practical difference, but could union the next
3 to indicate (assuming I haven't missed anything) that they are never used
in the same transfers and I think all sit under the same lock.
> +	unsigned short			data ____cacheline_aligned;
> +	unsigned short			phase_data[2] ;
> +	unsigned short			freq_data[4] ;
> +};
> +
> +/*
> + * TODO: struct ad9832_platform_data needs to go into include/linux/iio
> + */
> +
> +/**
> + * struct ad9832_platform_data - platform specific information
> + * @mclk:		master clock in Hz
> + * @freq0:		power up freq0 tuning word in Hz
> + * @freq1:		power up freq1 tuning word in Hz
> + * @phase0:		power up phase0 value [0..4095] correlates with 0..2PI
> + * @phase1:		power up phase1 value [0..4095] correlates with 0..2PI
> + * @phase2:		power up phase2 value [0..4095] correlates with 0..2PI
> + * @phase3:		power up phase3 value [0..4095] correlates with 0..2PI
> + */
> +
> +struct ad9832_platform_data {
> +	unsigned int		mclk;
> +	unsigned long		freq0;
> +	unsigned long		freq1;
> +	unsigned short		phase0;
> +	unsigned short		phase1;
> +	unsigned short		phase2;
> +	unsigned short		phase3;
> +};
> +
> +/**
> + * ad9832_supported_device_ids:
> + */
> +
Can't see any use being made of these in the code.
Lets not differentiate the chips unless we need to.

> +enum ad9832_supported_device_ids {
> +	ID_AD9832,
> +	ID_AD9835,
> +};
> +
> +#endif /* IIO_DDS_AD9832_H_ */