Re: [PATCH v4 01/11] staging:iio:hmc5843: Use SCALE instead of magn_range

[Jonathan Cameron <jic23@kernel.org>]

On 10/16/13 23:19, Peter Meerwald wrote:
> v3:
> * rename _check_scale() to _get_scale_index()
> v2:
> * use SCALE instead of CALIBSCALE to control the range/gain
>   of measurements
> 
> Signed-off-by: Peter Meerwald <pmeerw@pmeerw.net>
Applied to the togreg branch of iio.git

Thanks
> ---
>  drivers/staging/iio/magnetometer/hmc5843.c | 160 +++++++++++------------------
>  1 file changed, 59 insertions(+), 101 deletions(-)
> 
> diff --git a/drivers/staging/iio/magnetometer/hmc5843.c b/drivers/staging/iio/magnetometer/hmc5843.c
> index b29622c..c56db41 100644
> --- a/drivers/staging/iio/magnetometer/hmc5843.c
> +++ b/drivers/staging/iio/magnetometer/hmc5843.c
> @@ -49,7 +49,7 @@ enum hmc5843_ids {
>   */
>  #define HMC5843_RANGE_GAIN_OFFSET		0x05
>  #define HMC5843_RANGE_GAIN_DEFAULT		0x01
> -#define HMC5843_RANGE_GAIN_MAX			0x07
> +#define HMC5843_RANGE_GAINS			8
>  
>  /* Device status */
>  #define HMC5843_DATA_READY			0x01
> @@ -79,65 +79,19 @@ enum hmc5843_ids {
>  #define HMC5843_MEAS_CONF_MASK			0x03
>  
>  /* Scaling factors: 10000000/Gain */
> -static const int hmc5843_regval_to_nanoscale[] = {
> +static const int hmc5843_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
>  	6173, 7692, 10309, 12821, 18868, 21739, 25641, 35714
>  };
>  
> -static const int hmc5883_regval_to_nanoscale[] = {
> +static const int hmc5883_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
>  	7812, 9766, 13021, 16287, 24096, 27701, 32573, 45662
>  };
>  
> -static const int hmc5883l_regval_to_nanoscale[] = {
> +static const int hmc5883l_regval_to_nanoscale[HMC5843_RANGE_GAINS] = {
>  	7299, 9174, 12195, 15152, 22727, 25641, 30303, 43478
>  };
>  
>  /*
> - * From the HMC5843 datasheet:
> - * Value	| Sensor input field range (Ga)	| Gain (counts/milli-Gauss)
> - * 0		| (+-)0.7			| 1620
> - * 1		| (+-)1.0			| 1300
> - * 2		| (+-)1.5			| 970
> - * 3		| (+-)2.0			| 780
> - * 4		| (+-)3.2			| 530
> - * 5		| (+-)3.8			| 460
> - * 6		| (+-)4.5			| 390
> - * 7		| (+-)6.5			| 280
> - *
> - * From the HMC5883 datasheet:
> - * Value	| Recommended sensor field range (Ga)	| Gain (counts/Gauss)
> - * 0		| (+-)0.9				| 1280
> - * 1		| (+-)1.2				| 1024
> - * 2		| (+-)1.9				| 768
> - * 3		| (+-)2.5				| 614
> - * 4		| (+-)4.0				| 415
> - * 5		| (+-)4.6				| 361
> - * 6		| (+-)5.5				| 307
> - * 7		| (+-)7.9				| 219
> - *
> - * From the HMC5883L datasheet:
> - * Value	| Recommended sensor field range (Ga)	| Gain (LSB/Gauss)
> - * 0		| (+-)0.88				| 1370
> - * 1		| (+-)1.3				| 1090
> - * 2		| (+-)1.9				| 820
> - * 3		| (+-)2.5				| 660
> - * 4		| (+-)4.0				| 440
> - * 5		| (+-)4.7				| 390
> - * 6		| (+-)5.6				| 330
> - * 7		| (+-)8.1				| 230
> - */
> -static const int hmc5843_regval_to_input_field_mga[] = {
> -	700, 1000, 1500, 2000, 3200, 3800, 4500, 6500
> -};
> -
> -static const int hmc5883_regval_to_input_field_mga[] = {
> -	900, 1200, 1900, 2500, 4000, 4600, 5500, 7900
> -};
> -
> -static const int hmc5883l_regval_to_input_field_mga[] = {
> -	880, 1300, 1900, 2500, 4000, 4700, 5600, 8100
> -};
> -
> -/*
>   * From the datasheet:
>   * Value	| HMC5843		| HMC5883/HMC5883L
>   *		| Data output rate (Hz)	| Data output rate (Hz)
> @@ -163,7 +117,6 @@ static const int hmc5883_regval_to_samp_freq[7][2] = {
>  struct hmc5843_chip_info {
>  	const struct iio_chan_spec *channels;
>  	const int (*regval_to_samp_freq)[2];
> -	const int *regval_to_input_field_mga;
>  	const int *regval_to_nanoscale;
>  };
>  
> @@ -412,58 +365,41 @@ static int hmc5843_check_samp_freq(struct hmc5843_data *data,
>  		val, val2);
>  }
>  
> -static ssize_t hmc5843_show_range_gain(struct device *dev,
> -				struct device_attribute *attr,
> -				char *buf)
> +static ssize_t hmc5843_show_scale_avail(struct device *dev,
> +				struct device_attribute *attr, char *buf)
>  {
> -	u8 range;
> -	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> -	struct hmc5843_data *data = iio_priv(indio_dev);
> +	struct hmc5843_data *data = iio_priv(dev_to_iio_dev(dev));
> +
> +	size_t len = 0;
> +	int i;
>  
> -	range = data->range;
> -	return sprintf(buf, "%d\n", data->variant->regval_to_input_field_mga[range]);
> +	for (i = 0; i < HMC5843_RANGE_GAINS; i++)
> +		len += scnprintf(buf + len, PAGE_SIZE - len,
> +			"0.%09d ", data->variant->regval_to_nanoscale[i]);
> +
> +	/* replace trailing space by newline */
> +	buf[len - 1] = '\n';
> +
> +	return len;
>  }
>  
> -static ssize_t hmc5843_set_range_gain(struct device *dev,
> -			struct device_attribute *attr,
> -			const char *buf,
> -			size_t count)
> -{
> -	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> -	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
> -	struct hmc5843_data *data = iio_priv(indio_dev);
> -	unsigned long range = 0;
> -	int error;
> +static IIO_DEVICE_ATTR(scale_available, S_IRUGO,
> +	hmc5843_show_scale_avail, NULL, 0);
>  
> -	mutex_lock(&data->lock);
> -	error = kstrtoul(buf, 10, &range);
> -	if (error) {
> -		count = error;
> -		goto exit;
> -	}
> -	dev_dbg(dev, "set range to %lu\n", range);
> +static int hmc5843_get_scale_index(struct hmc5843_data *data, int val, int val2)
> +{
> +	int i;
>  
> -	if (range > HMC5843_RANGE_GAIN_MAX) {
> -		count = -EINVAL;
> -		goto exit;
> -	}
> +	if (val != 0)
> +		return -EINVAL;
>  
> -	data->range = range;
> -	range = range << HMC5843_RANGE_GAIN_OFFSET;
> -	if (i2c_smbus_write_byte_data(data->client, this_attr->address, range))
> -		count = -EINVAL;
> +	for (i = 0; i < HMC5843_RANGE_GAINS; i++)
> +		if (val2 == data->variant->regval_to_nanoscale[i])
> +			return i;
>  
> -exit:
> -	mutex_unlock(&data->lock);
> -	return count;
> +	return -EINVAL;
>  }
>  
> -static IIO_DEVICE_ATTR(in_magn_range,
> -			S_IWUSR | S_IRUGO,
> -			hmc5843_show_range_gain,
> -			hmc5843_set_range_gain,
> -			HMC5843_CONFIG_REG_B);
> -
>  static int hmc5843_read_raw(struct iio_dev *indio_dev,
>  			    struct iio_chan_spec const *chan,
>  			    int *val, int *val2, long mask)
> @@ -490,7 +426,7 @@ static int hmc5843_write_raw(struct iio_dev *indio_dev,
>  			     int val, int val2, long mask)
>  {
>  	struct hmc5843_data *data = iio_priv(indio_dev);
> -	int ret, rate;
> +	int ret, rate, range;
>  
>  	switch (mask) {
>  	case IIO_CHAN_INFO_SAMP_FREQ:
> @@ -505,6 +441,33 @@ static int hmc5843_write_raw(struct iio_dev *indio_dev,
>  		mutex_unlock(&data->lock);
>  
>  		return ret;
> +	case IIO_CHAN_INFO_SCALE:
> +		range = hmc5843_get_scale_index(data, val, val2);
> +		if (range < 0)
> +			return -EINVAL;
> +
> +		range <<= HMC5843_RANGE_GAIN_OFFSET;
> +		mutex_lock(&data->lock);
> +		ret = i2c_smbus_write_byte_data(data->client,
> +			HMC5843_CONFIG_REG_B, range);
> +		if (ret >= 0)
> +			data->range = range;
> +		mutex_unlock(&data->lock);
> +
> +		return ret;
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int hmc5843_write_raw_get_fmt(struct iio_dev *indio_dev,
> +			       struct iio_chan_spec const *chan, long mask)
> +{
> +	switch (mask) {
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		return IIO_VAL_INT_PLUS_MICRO;
> +	case IIO_CHAN_INFO_SCALE:
> +		return IIO_VAL_INT_PLUS_NANO;
>  	default:
>  		return -EINVAL;
>  	}
> @@ -536,7 +499,7 @@ static const struct iio_chan_spec hmc5883_channels[] = {
>  static struct attribute *hmc5843_attributes[] = {
>  	&iio_dev_attr_meas_conf.dev_attr.attr,
>  	&iio_dev_attr_operating_mode.dev_attr.attr,
> -	&iio_dev_attr_in_magn_range.dev_attr.attr,
> +	&iio_dev_attr_scale_available.dev_attr.attr,
>  	&iio_dev_attr_sampling_frequency_available.dev_attr.attr,
>  	NULL
>  };
> @@ -549,22 +512,16 @@ static const struct hmc5843_chip_info hmc5843_chip_info_tbl[] = {
>  	[HMC5843_ID] = {
>  		.channels = hmc5843_channels,
>  		.regval_to_samp_freq = hmc5843_regval_to_samp_freq,
> -		.regval_to_input_field_mga =
> -			hmc5843_regval_to_input_field_mga,
>  		.regval_to_nanoscale = hmc5843_regval_to_nanoscale,
>  	},
>  	[HMC5883_ID] = {
>  		.channels = hmc5883_channels,
>  		.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
> -		.regval_to_input_field_mga =
> -			hmc5883_regval_to_input_field_mga,
>  		.regval_to_nanoscale = hmc5883_regval_to_nanoscale,
>  	},
>  	[HMC5883L_ID] = {
>  		.channels = hmc5883_channels,
>  		.regval_to_samp_freq = hmc5883_regval_to_samp_freq,
> -		.regval_to_input_field_mga =
> -			hmc5883l_regval_to_input_field_mga,
>  		.regval_to_nanoscale = hmc5883l_regval_to_nanoscale,
>  	},
>  };
> @@ -582,6 +539,7 @@ static const struct iio_info hmc5843_info = {
>  	.attrs = &hmc5843_group,
>  	.read_raw = &hmc5843_read_raw,
>  	.write_raw = &hmc5843_write_raw,
> +	.write_raw_get_fmt = &hmc5843_write_raw_get_fmt,
>  	.driver_module = THIS_MODULE,
>  };
>  
>