Re: [RFC 5/8] staging:iio:dac:ad5504: Convert to extended channel attributes

[Jonathan Cameron <jic23@kernel.org>]

On 05/11/2012 04:53 PM, Lars-Peter Clausen wrote:
> Use extended channel attributes instead of raw sysfs files for the additional
> channel attributes. This allows us to remove some boilerplate code.

One trivial point inline...
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Jonathan Cameron <jic23@kernel.org>
> ---
>  drivers/staging/iio/dac/ad5504.c |  164 ++++++++++++++------------------------
>  1 file changed, 58 insertions(+), 106 deletions(-)
> 
> diff --git a/drivers/staging/iio/dac/ad5504.c b/drivers/staging/iio/dac/ad5504.c
> index db84d85..07b31f4 100644
> --- a/drivers/staging/iio/dac/ad5504.c
> +++ b/drivers/staging/iio/dac/ad5504.c
> @@ -22,24 +22,6 @@
>  
>  #include "ad5504.h"
>  
> -#define AD5504_CHANNEL(_chan) { \
> -	.type = IIO_VOLTAGE, \
> -	.indexed = 1, \
> -	.output = 1, \
> -	.channel = (_chan), \
> -	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
> -		     IIO_CHAN_INFO_SCALE_SHARED_BIT, \
> -	.address = AD5504_ADDR_DAC(_chan), \
> -	.scan_type = IIO_ST('u', 12, 16, 0), \
> -}
> -
> -static const struct iio_chan_spec ad5504_channels[] = {
> -	AD5504_CHANNEL(0),
> -	AD5504_CHANNEL(1),
> -	AD5504_CHANNEL(2),
> -	AD5504_CHANNEL(3),
> -};
> -
>  static int ad5504_spi_write(struct spi_device *spi, u8 addr, u16 val)
>  {
>  	u16 tmp = cpu_to_be16(AD5504_CMD_WRITE |
> @@ -122,65 +104,60 @@ static int ad5504_write_raw(struct iio_dev *indio_dev,
>  	return -EINVAL;
>  }
>  
> -static ssize_t ad5504_read_powerdown_mode(struct device *dev,
> -				      struct device_attribute *attr, char *buf)
> +static const char * const ad5504_powerdown_modes[] = {
> +	"20kohm_to_gnd",
> +	"three_state",
> +};
> +
> +static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev,
> +	const struct iio_chan_spec *chan)
>  {
> -	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct ad5504_state *st = iio_priv(indio_dev);
>  
> -	const char mode[][14] = {"20kohm_to_gnd", "three_state"};
> -
> -	return sprintf(buf, "%s\n", mode[st->pwr_down_mode]);
> +	return st->pwr_down_mode;
>  }
>  
> -static ssize_t ad5504_write_powerdown_mode(struct device *dev,
> -				       struct device_attribute *attr,
> -				       const char *buf, size_t len)
> +static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev,
> +	const struct iio_chan_spec *chan, unsigned int mode)
>  {
> -	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct ad5504_state *st = iio_priv(indio_dev);
> -	int ret;
> -
> -	if (sysfs_streq(buf, "20kohm_to_gnd"))
> -		st->pwr_down_mode = AD5504_DAC_PWRDN_20K;
> -	else if (sysfs_streq(buf, "three_state"))
> -		st->pwr_down_mode = AD5504_DAC_PWRDN_3STATE;
> -	else
> -		ret = -EINVAL;
>  
> -	return ret ? ret : len;
> +	st->pwr_down_mode = mode;
blank line here.
> +	return 0;
>  }
>  
> -static ssize_t ad5504_read_dac_powerdown(struct device *dev,
> -					   struct device_attribute *attr,
> -					   char *buf)
> +static const struct iio_enum ad5504_powerdown_mode_enum = {
> +	.items = ad5504_powerdown_modes,
> +	.num_items = ARRAY_SIZE(ad5504_powerdown_modes),
> +	.get = ad5504_get_powerdown_mode,
> +	.set = ad5504_set_powerdown_mode,
> +};
> +
> +static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev,
> +	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
>  {
> -	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct ad5504_state *st = iio_priv(indio_dev);
> -	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
>  
>  	return sprintf(buf, "%d\n",
> -			!(st->pwr_down_mask & (1 << this_attr->address)));
> +			!(st->pwr_down_mask & (1 << chan->channel)));
>  }
>  
> -static ssize_t ad5504_write_dac_powerdown(struct device *dev,
> -					    struct device_attribute *attr,
> -					    const char *buf, size_t len)
> +static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev,
> +	uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
> +	size_t len)
>  {
>  	long readin;
>  	int ret;
> -	struct iio_dev *indio_dev = dev_get_drvdata(dev);
>  	struct ad5504_state *st = iio_priv(indio_dev);
> -	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
>  
>  	ret = strict_strtol(buf, 10, &readin);
>  	if (ret)
>  		return ret;
>  
>  	if (readin == 0)
> -		st->pwr_down_mask |= (1 << this_attr->address);
> +		st->pwr_down_mask |= (1 << chan->channel);
>  	else if (readin == 1)
> -		st->pwr_down_mask &= ~(1 << this_attr->address);
> +		st->pwr_down_mask &= ~(1 << chan->channel);
>  	else
>  		ret = -EINVAL;
>  
> @@ -194,50 +171,6 @@ static ssize_t ad5504_write_dac_powerdown(struct device *dev,
>  	return ret ? ret : len;
>  }
>  
> -static IIO_DEVICE_ATTR(out_voltage_powerdown_mode, S_IRUGO |
> -			S_IWUSR, ad5504_read_powerdown_mode,
> -			ad5504_write_powerdown_mode, 0);
> -
> -static IIO_CONST_ATTR(out_voltage_powerdown_mode_available,
> -			"20kohm_to_gnd three_state");
> -
> -#define IIO_DEV_ATTR_DAC_POWERDOWN(_num, _show, _store, _addr)		\
> -	IIO_DEVICE_ATTR(out_voltage##_num##_powerdown,			\
> -			S_IRUGO | S_IWUSR, _show, _store, _addr)
> -static IIO_DEV_ATTR_DAC_POWERDOWN(0, ad5504_read_dac_powerdown,
> -				   ad5504_write_dac_powerdown, 0);
> -static IIO_DEV_ATTR_DAC_POWERDOWN(1, ad5504_read_dac_powerdown,
> -				   ad5504_write_dac_powerdown, 1);
> -static IIO_DEV_ATTR_DAC_POWERDOWN(2, ad5504_read_dac_powerdown,
> -				   ad5504_write_dac_powerdown, 2);
> -static IIO_DEV_ATTR_DAC_POWERDOWN(3, ad5504_read_dac_powerdown,
> -				   ad5504_write_dac_powerdown, 3);
> -
> -static struct attribute *ad5504_attributes[] = {
> -	&iio_dev_attr_out_voltage0_powerdown.dev_attr.attr,
> -	&iio_dev_attr_out_voltage1_powerdown.dev_attr.attr,
> -	&iio_dev_attr_out_voltage2_powerdown.dev_attr.attr,
> -	&iio_dev_attr_out_voltage3_powerdown.dev_attr.attr,
> -	&iio_dev_attr_out_voltage_powerdown_mode.dev_attr.attr,
> -	&iio_const_attr_out_voltage_powerdown_mode_available.dev_attr.attr,
> -	NULL,
> -};
> -
> -static const struct attribute_group ad5504_attribute_group = {
> -	.attrs = ad5504_attributes,
> -};
> -
> -static struct attribute *ad5501_attributes[] = {
> -	&iio_dev_attr_out_voltage0_powerdown.dev_attr.attr,
> -	&iio_dev_attr_out_voltage_powerdown_mode.dev_attr.attr,
> -	&iio_const_attr_out_voltage_powerdown_mode_available.dev_attr.attr,
> -	NULL,
> -};
> -
> -static const struct attribute_group ad5501_attribute_group = {
> -	.attrs = ad5501_attributes,
> -};
> -
>  static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000");
>  static IIO_CONST_ATTR(temp0_thresh_rising_en, "1");
>  
> @@ -267,17 +200,38 @@ static irqreturn_t ad5504_event_handler(int irq, void *private)
>  static const struct iio_info ad5504_info = {
>  	.write_raw = ad5504_write_raw,
>  	.read_raw = ad5504_read_raw,
> -	.attrs = &ad5504_attribute_group,
>  	.event_attrs = &ad5504_ev_attribute_group,
>  	.driver_module = THIS_MODULE,
>  };
>  
> -static const struct iio_info ad5501_info = {
> -	.write_raw = ad5504_write_raw,
> -	.read_raw = ad5504_read_raw,
> -	.attrs = &ad5501_attribute_group,
> -	.event_attrs = &ad5504_ev_attribute_group,
> -	.driver_module = THIS_MODULE,
> +static const struct iio_chan_spec_ext_info ad5504_ext_info[] = {
> +	{
> +		.name = "powerdown",
> +		.read = ad5504_read_dac_powerdown,
> +		.write = ad5504_write_dac_powerdown,
> +	},
> +	IIO_ENUM("powerdown_mode", true, &ad5504_powerdown_mode_enum),
> +	IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum),
> +	{ },
> +};
> +
> +#define AD5504_CHANNEL(_chan) { \
> +	.type = IIO_VOLTAGE, \
> +	.indexed = 1, \
> +	.output = 1, \
> +	.channel = (_chan), \
> +	.info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \
> +		     IIO_CHAN_INFO_SCALE_SHARED_BIT, \
> +	.address = AD5504_ADDR_DAC(_chan), \
> +	.scan_type = IIO_ST('u', 12, 16, 0), \
> +	.ext_info = ad5504_ext_info, \
> +}
> +
> +static const struct iio_chan_spec ad5504_channels[] = {
> +	AD5504_CHANNEL(0),
> +	AD5504_CHANNEL(1),
> +	AD5504_CHANNEL(2),
> +	AD5504_CHANNEL(3),
>  };
>  
>  static int __devinit ad5504_probe(struct spi_device *spi)
> @@ -315,13 +269,11 @@ static int __devinit ad5504_probe(struct spi_device *spi)
>  	st->spi = spi;
>  	indio_dev->dev.parent = &spi->dev;
>  	indio_dev->name = spi_get_device_id(st->spi)->name;
> -	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501) {
> -		indio_dev->info = &ad5501_info;
> +	indio_dev->info = &ad5504_info;
> +	if (spi_get_device_id(st->spi)->driver_data == ID_AD5501)
>  		indio_dev->num_channels = 1;
> -	} else {
> -		indio_dev->info = &ad5504_info;
> +	else
>  		indio_dev->num_channels = 4;
> -	}
>  	indio_dev->channels = ad5504_channels;
>  	indio_dev->modes = INDIO_DIRECT_MODE;
>