diff mbox series

[v3,1/4] staging: iio: ad7780: add gain & filter gpio support

Message ID 786543cbd8d60776083bcaca66f83502f23f561b.1549385784.git.renatogeh@gmail.com (mailing list archive)
State New, archived
Headers show
Series staging: iio: ad7780: move out of staging | expand

Commit Message

Renato Lui Geh Feb. 5, 2019, 5:13 p.m. UTC
Previously, the AD7780 driver only supported gpio for the 'powerdown'
pin. This commit adds suppport for the 'gain' and 'filter' pin.

Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
---
Changes in v3:
	- Renamed ad7780_chip_info's filter to odr
	- Renamed ad778x_filter to ad778x_odr_avail
	- Changed vref variable from unsigned int to unsigned long long to
	  avoid overflow
	- Removed unnecessary AD_SD_CHANNEL macro

 drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
 1 file changed, 89 insertions(+), 6 deletions(-)

Comments

Peter Meerwald-Stadler Feb. 5, 2019, 7:58 p.m. UTC | #1
On Tue, 5 Feb 2019, Renato Lui Geh wrote:

> Previously, the AD7780 driver only supported gpio for the 'powerdown'
> pin. This commit adds suppport for the 'gain' and 'filter' pin.

comments below
 
> Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
> ---
> Changes in v3:
> 	- Renamed ad7780_chip_info's filter to odr
> 	- Renamed ad778x_filter to ad778x_odr_avail
> 	- Changed vref variable from unsigned int to unsigned long long to
> 	  avoid overflow
> 	- Removed unnecessary AD_SD_CHANNEL macro
> 
> drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
> 1 file changed, 89 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/iio/adc/ad7780.c
> b/drivers/staging/iio/adc/ad7780.c
> index c4a85789c2db..6e4357800d31 100644
> --- a/drivers/staging/iio/adc/ad7780.c
> +++ b/drivers/staging/iio/adc/ad7780.c
> @@ -39,6 +39,15 @@
> #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
> #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
> 
> +#define AD7780_GAIN_GPIO	0
> +#define AD7780_FILTER_GPIO	1
> +
> +#define AD7780_GAIN_MIDPOINT	64
> +#define AD7780_FILTER_MIDPOINT	13350
> +
> +static const unsigned int ad778x_gain[2]      = { 1, 128 };
> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
> +
> struct ad7780_chip_info {
> 	struct iio_chan_spec	channel;
> 	unsigned int		pattern_mask;
> @@ -50,7 +59,11 @@ struct ad7780_state {
> 	const struct ad7780_chip_info	*chip_info;
> 	struct regulator		*reg;
> 	struct gpio_desc		*powerdown_gpio;
> -	unsigned int	gain;
> +	struct gpio_desc		*gain_gpio;
> +	struct gpio_desc		*filter_gpio;
> +	unsigned int			gain;
> +	unsigned int			odr;
> +	unsigned int			int_vref_mv;
> 
> 	struct ad_sigma_delta sd;
> };
> @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
> 		voltage_uv = regulator_get_voltage(st->reg);
> 		if (voltage_uv < 0)
> 			return voltage_uv;
> -		*val = (voltage_uv / 1000) * st->gain;
> +		voltage_uv /= 1000;
> +		*val = voltage_uv * st->gain;
> 		*val2 = chan->scan_type.realbits - 1;
> +		st->int_vref_mv = voltage_uv;
> 		return IIO_VAL_FRACTIONAL_LOG2;
> 	case IIO_CHAN_INFO_OFFSET:
> 		*val = -(1 << (chan->scan_type.realbits - 1));
> 		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SAMP_FREQ:

was this missing before?
this is not covered by the patch description and seems unrelated
needs to be added to the channel spec?

> +		*val = st->odr;
> +		return IIO_VAL_INT;
> 	}
> 
> 	return -EINVAL;
> }
> 
> +static int ad7780_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val,
> +			    int val2,
> +			    long m)
> +{
> +	struct ad7780_state *st = iio_priv(indio_dev);
> +	const struct ad7780_chip_info *chip_info = st->chip_info;
> +	unsigned long long vref;
> +	unsigned int full_scale, gain;
> +
> +	if (!chip_info->is_ad778x)
> +		return 0;
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_SCALE:
> +		if (val != 0)
> +			return -EINVAL;
> +
> +		vref = st->int_vref_mv * 1000000LL;
> +		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
> +		gain = DIV_ROUND_CLOSEST(vref, full_scale);
> +		gain = DIV_ROUND_CLOSEST(gain, val2);
> +		st->gain = gain;
> +		if (gain < AD7780_GAIN_MIDPOINT)
> +			gain = 0;
> +		else
> +			gain = 1;
> +		gpiod_set_value(st->gain_gpio, gain);
> +	break;

indentation with the other, previous statements

> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)

space around operators missing

> +			val = 0;
> +		else
> +			val = 1;
> +		st->odr = ad778x_odr_avail[val];
> +		gpiod_set_value(st->filter_gpio, val);
> +	break;
> +	}
> +
> +	return 0;
> +}
> +
> static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> 				     unsigned int raw_sample)
> {
> @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct
> ad_sigma_delta *sigma_delta,
> 		return -EIO;
> 
> 	if (chip_info->is_ad778x) {
> -		if (raw_sample & AD7780_GAIN)
> -			st->gain = 1;
> -		else
> -			st->gain = 128;
> +		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
> +		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
> 	}
> 
> 	return 0;
> @@ -173,6 +232,7 @@ static const struct ad7780_chip_info
> ad7780_chip_info_tbl[] = {
> 
> static const struct iio_info ad7780_info = {
> 	.read_raw = ad7780_read_raw,
> +	.write_raw = ad7780_write_raw,
> };
> 
> static int ad7780_probe(struct spi_device *spi)
> @@ -222,6 +282,29 @@ static int ad7780_probe(struct spi_device *spi)
> 		goto error_disable_reg;
> 	}
> 
> +	if (st->chip_info->is_ad778x) {
> +		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
> +							"gain",
> +							GPIOD_OUT_HIGH);
> +		if (IS_ERR(st->gain_gpio)) {
> +			ret = PTR_ERR(st->gain_gpio);
> +			dev_err(&spi->dev, "Failed to request gain GPIO:
> %d\n",
> +				ret);
> +			goto error_disable_reg;
> +		}
> +
> +		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
> +							  "filter",
> +							  GPIOD_OUT_HIGH);
> +		if (IS_ERR(st->filter_gpio)) {
> +			ret = PTR_ERR(st->filter_gpio);
> +			dev_err(&spi->dev,
> +				"Failed to request filter GPIO: %d\n",
> +				ret);
> +			goto error_disable_reg;
> +		}
> +	}
> +
> 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
> 	if (ret)
> 		goto error_disable_reg;
>
Renato Lui Geh Feb. 5, 2019, 8:21 p.m. UTC | #2
Hi Peter,

Thank you for the review! Comments inline.

Renato

On 02/05, Peter Meerwald-Stadler wrote:
>On Tue, 5 Feb 2019, Renato Lui Geh wrote:
>
>> Previously, the AD7780 driver only supported gpio for the 'powerdown'
>> pin. This commit adds suppport for the 'gain' and 'filter' pin.
>
>comments below
>
>> Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
>> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
>> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
>> ---
>> Changes in v3:
>> 	- Renamed ad7780_chip_info's filter to odr
>> 	- Renamed ad778x_filter to ad778x_odr_avail
>> 	- Changed vref variable from unsigned int to unsigned long long to
>> 	  avoid overflow
>> 	- Removed unnecessary AD_SD_CHANNEL macro
>>
>> drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
>> 1 file changed, 89 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/staging/iio/adc/ad7780.c
>> b/drivers/staging/iio/adc/ad7780.c
>> index c4a85789c2db..6e4357800d31 100644
>> --- a/drivers/staging/iio/adc/ad7780.c
>> +++ b/drivers/staging/iio/adc/ad7780.c
>> @@ -39,6 +39,15 @@
>> #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
>> #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
>>
>> +#define AD7780_GAIN_GPIO	0
>> +#define AD7780_FILTER_GPIO	1
>> +
>> +#define AD7780_GAIN_MIDPOINT	64
>> +#define AD7780_FILTER_MIDPOINT	13350
>> +
>> +static const unsigned int ad778x_gain[2]      = { 1, 128 };
>> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
>> +
>> struct ad7780_chip_info {
>> 	struct iio_chan_spec	channel;
>> 	unsigned int		pattern_mask;
>> @@ -50,7 +59,11 @@ struct ad7780_state {
>> 	const struct ad7780_chip_info	*chip_info;
>> 	struct regulator		*reg;
>> 	struct gpio_desc		*powerdown_gpio;
>> -	unsigned int	gain;
>> +	struct gpio_desc		*gain_gpio;
>> +	struct gpio_desc		*filter_gpio;
>> +	unsigned int			gain;
>> +	unsigned int			odr;
>> +	unsigned int			int_vref_mv;
>>
>> 	struct ad_sigma_delta sd;
>> };
>> @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
>> 		voltage_uv = regulator_get_voltage(st->reg);
>> 		if (voltage_uv < 0)
>> 			return voltage_uv;
>> -		*val = (voltage_uv / 1000) * st->gain;
>> +		voltage_uv /= 1000;
>> +		*val = voltage_uv * st->gain;
>> 		*val2 = chan->scan_type.realbits - 1;
>> +		st->int_vref_mv = voltage_uv;
>> 		return IIO_VAL_FRACTIONAL_LOG2;
>> 	case IIO_CHAN_INFO_OFFSET:
>> 		*val = -(1 << (chan->scan_type.realbits - 1));
>> 		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>
>was this missing before?
>this is not covered by the patch description and seems unrelated
>needs to be added to the channel spec?

Yes, this is a new feature. Should I have this chunk sent as a separate
patch?

What is the channel spec? How would I add this to the channel spec?

>
>> +		*val = st->odr;
>> +		return IIO_VAL_INT;
>> 	}
>>
>> 	return -EINVAL;
>> }
>>
>> +static int ad7780_write_raw(struct iio_dev *indio_dev,
>> +			    struct iio_chan_spec const *chan,
>> +			    int val,
>> +			    int val2,
>> +			    long m)
>> +{
>> +	struct ad7780_state *st = iio_priv(indio_dev);
>> +	const struct ad7780_chip_info *chip_info = st->chip_info;
>> +	unsigned long long vref;
>> +	unsigned int full_scale, gain;
>> +
>> +	if (!chip_info->is_ad778x)
>> +		return 0;
>> +
>> +	switch (m) {
>> +	case IIO_CHAN_INFO_SCALE:
>> +		if (val != 0)
>> +			return -EINVAL;
>> +
>> +		vref = st->int_vref_mv * 1000000LL;
>> +		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
>> +		gain = DIV_ROUND_CLOSEST(vref, full_scale);
>> +		gain = DIV_ROUND_CLOSEST(gain, val2);
>> +		st->gain = gain;
>> +		if (gain < AD7780_GAIN_MIDPOINT)
>> +			gain = 0;
>> +		else
>> +			gain = 1;
>> +		gpiod_set_value(st->gain_gpio, gain);
>> +	break;
>
>indentation with the other, previous statements
>
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
>
>space around operators missing
>
>> +			val = 0;
>> +		else
>> +			val = 1;
>> +		st->odr = ad778x_odr_avail[val];
>> +		gpiod_set_value(st->filter_gpio, val);
>> +	break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
>> 				     unsigned int raw_sample)
>> {
>> @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct
>> ad_sigma_delta *sigma_delta,
>> 		return -EIO;
>>
>> 	if (chip_info->is_ad778x) {
>> -		if (raw_sample & AD7780_GAIN)
>> -			st->gain = 1;
>> -		else
>> -			st->gain = 128;
>> +		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
>> +		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
>> 	}
>>
>> 	return 0;
>> @@ -173,6 +232,7 @@ static const struct ad7780_chip_info
>> ad7780_chip_info_tbl[] = {
>>
>> static const struct iio_info ad7780_info = {
>> 	.read_raw = ad7780_read_raw,
>> +	.write_raw = ad7780_write_raw,
>> };
>>
>> static int ad7780_probe(struct spi_device *spi)
>> @@ -222,6 +282,29 @@ static int ad7780_probe(struct spi_device *spi)
>> 		goto error_disable_reg;
>> 	}
>>
>> +	if (st->chip_info->is_ad778x) {
>> +		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
>> +							"gain",
>> +							GPIOD_OUT_HIGH);
>> +		if (IS_ERR(st->gain_gpio)) {
>> +			ret = PTR_ERR(st->gain_gpio);
>> +			dev_err(&spi->dev, "Failed to request gain GPIO:
>> %d\n",
>> +				ret);
>> +			goto error_disable_reg;
>> +		}
>> +
>> +		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
>> +							  "filter",
>> +							  GPIOD_OUT_HIGH);
>> +		if (IS_ERR(st->filter_gpio)) {
>> +			ret = PTR_ERR(st->filter_gpio);
>> +			dev_err(&spi->dev,
>> +				"Failed to request filter GPIO: %d\n",
>> +				ret);
>> +			goto error_disable_reg;
>> +		}
>> +	}
>> +
>> 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
>> 	if (ret)
>> 		goto error_disable_reg;
>>
>
>-- 
>
>Peter Meerwald-Stadler
>Mobile: +43 664 24 44 418
Jonathan Cameron Feb. 9, 2019, 4:25 p.m. UTC | #3
On Tue, 5 Feb 2019 15:13:00 -0200
Renato Lui Geh <renatogeh@gmail.com> wrote:

> Previously, the AD7780 driver only supported gpio for the 'powerdown'
> pin. This commit adds suppport for the 'gain' and 'filter' pin.
> 
> Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
Comments inline.

> ---
> Changes in v3:
> 	- Renamed ad7780_chip_info's filter to odr
> 	- Renamed ad778x_filter to ad778x_odr_avail
> 	- Changed vref variable from unsigned int to unsigned long long to
> 	  avoid overflow
> 	- Removed unnecessary AD_SD_CHANNEL macro
> 
>  drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
>  1 file changed, 89 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
> index c4a85789c2db..6e4357800d31 100644
> --- a/drivers/staging/iio/adc/ad7780.c
> +++ b/drivers/staging/iio/adc/ad7780.c
> @@ -39,6 +39,15 @@
>  #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
>  #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
>  
> +#define AD7780_GAIN_GPIO	0
> +#define AD7780_FILTER_GPIO	1
What are these for?

> +
> +#define AD7780_GAIN_MIDPOINT	64
> +#define AD7780_FILTER_MIDPOINT	13350
> +
> +static const unsigned int ad778x_gain[2]      = { 1, 128 };
> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
> +
>  struct ad7780_chip_info {
>  	struct iio_chan_spec	channel;
>  	unsigned int		pattern_mask;
> @@ -50,7 +59,11 @@ struct ad7780_state {
>  	const struct ad7780_chip_info	*chip_info;
>  	struct regulator		*reg;
>  	struct gpio_desc		*powerdown_gpio;
> -	unsigned int	gain;
> +	struct gpio_desc		*gain_gpio;
> +	struct gpio_desc		*filter_gpio;
> +	unsigned int			gain;
> +	unsigned int			odr;
> +	unsigned int			int_vref_mv;
>  
>  	struct ad_sigma_delta sd;
>  };
> @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
>  		voltage_uv = regulator_get_voltage(st->reg);
>  		if (voltage_uv < 0)
>  			return voltage_uv;
> -		*val = (voltage_uv / 1000) * st->gain;
> +		voltage_uv /= 1000;
> +		*val = voltage_uv * st->gain;
>  		*val2 = chan->scan_type.realbits - 1;
> +		st->int_vref_mv = voltage_uv;
>  		return IIO_VAL_FRACTIONAL_LOG2;
>  	case IIO_CHAN_INFO_OFFSET:
>  		*val = -(1 << (chan->scan_type.realbits - 1));
>  		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		*val = st->odr;
> +		return IIO_VAL_INT;
>  	}
>  
>  	return -EINVAL;
>  }
>  
> +static int ad7780_write_raw(struct iio_dev *indio_dev,
> +			    struct iio_chan_spec const *chan,
> +			    int val,
> +			    int val2,
> +			    long m)
> +{
> +	struct ad7780_state *st = iio_priv(indio_dev);
> +	const struct ad7780_chip_info *chip_info = st->chip_info;
> +	unsigned long long vref;
> +	unsigned int full_scale, gain;
> +
> +	if (!chip_info->is_ad778x)
> +		return 0;
> +
> +	switch (m) {
> +	case IIO_CHAN_INFO_SCALE:
> +		if (val != 0)
> +			return -EINVAL;
> +
> +		vref = st->int_vref_mv * 1000000LL;
> +		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
> +		gain = DIV_ROUND_CLOSEST(vref, full_scale);
> +		gain = DIV_ROUND_CLOSEST(gain, val2);
> +		st->gain = gain;
> +		if (gain < AD7780_GAIN_MIDPOINT)
> +			gain = 0;
> +		else
> +			gain = 1;
> +		gpiod_set_value(st->gain_gpio, gain);
> +	break;
> +	case IIO_CHAN_INFO_SAMP_FREQ:
> +		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
> +			val = 0;
> +		else
> +			val = 1;
> +		st->odr = ad778x_odr_avail[val];
> +		gpiod_set_value(st->filter_gpio, val);
> +	break;
> +	}
> +
> +	return 0;
> +}
> +
>  static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
>  				     unsigned int raw_sample)
>  {
> @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
>  		return -EIO;
>  
>  	if (chip_info->is_ad778x) {
> -		if (raw_sample & AD7780_GAIN)
> -			st->gain = 1;
> -		else
> -			st->gain = 128;
> +		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
> +		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
>  	}
>  
>  	return 0;
> @@ -173,6 +232,7 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
>  
>  static const struct iio_info ad7780_info = {
>  	.read_raw = ad7780_read_raw,
> +	.write_raw = ad7780_write_raw,
>  };
>  
>  static int ad7780_probe(struct spi_device *spi)
> @@ -222,6 +282,29 @@ static int ad7780_probe(struct spi_device *spi)
>  		goto error_disable_reg;
>  	}
>  
> +	if (st->chip_info->is_ad778x) {
> +		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
> +							"gain",

These are not particularly standard names (basically not "reset"),
so they should be vendor prefixed, so that people know to go
look at the device specific binding.

> +							GPIOD_OUT_HIGH);
> +		if (IS_ERR(st->gain_gpio)) {
> +			ret = PTR_ERR(st->gain_gpio);
> +			dev_err(&spi->dev, "Failed to request gain GPIO: %d\n",
> +				ret);
> +			goto error_disable_reg;
> +		}
> +
> +		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
> +							  "filter",
> +							  GPIOD_OUT_HIGH);
> +		if (IS_ERR(st->filter_gpio)) {
> +			ret = PTR_ERR(st->filter_gpio);
> +			dev_err(&spi->dev,
> +				"Failed to request filter GPIO: %d\n",
> +				ret);
> +			goto error_disable_reg;
> +		}
> +	}
> +
>  	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
>  	if (ret)
>  		goto error_disable_reg;
Renato Lui Geh Feb. 14, 2019, 8:31 p.m. UTC | #4
Hi Jonathan,

Thanks for the review. Comments inline.

Renato

On 02/09, Jonathan Cameron wrote:
>On Tue, 5 Feb 2019 15:13:00 -0200
>Renato Lui Geh <renatogeh@gmail.com> wrote:
>
>> Previously, the AD7780 driver only supported gpio for the 'powerdown'
>> pin. This commit adds suppport for the 'gain' and 'filter' pin.
>>
>> Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
>> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
>> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
>Comments inline.
>
>> ---
>> Changes in v3:
>> 	- Renamed ad7780_chip_info's filter to odr
>> 	- Renamed ad778x_filter to ad778x_odr_avail
>> 	- Changed vref variable from unsigned int to unsigned long long to
>> 	  avoid overflow
>> 	- Removed unnecessary AD_SD_CHANNEL macro
>>
>>  drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
>>  1 file changed, 89 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
>> index c4a85789c2db..6e4357800d31 100644
>> --- a/drivers/staging/iio/adc/ad7780.c
>> +++ b/drivers/staging/iio/adc/ad7780.c
>> @@ -39,6 +39,15 @@
>>  #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
>>  #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
>>
>> +#define AD7780_GAIN_GPIO	0
>> +#define AD7780_FILTER_GPIO	1
>What are these for?

Sorry about that. That's leftover from a previous attempt.
>
>> +
>> +#define AD7780_GAIN_MIDPOINT	64
>> +#define AD7780_FILTER_MIDPOINT	13350
>> +
>> +static const unsigned int ad778x_gain[2]      = { 1, 128 };
>> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
>> +
>>  struct ad7780_chip_info {
>>  	struct iio_chan_spec	channel;
>>  	unsigned int		pattern_mask;
>> @@ -50,7 +59,11 @@ struct ad7780_state {
>>  	const struct ad7780_chip_info	*chip_info;
>>  	struct regulator		*reg;
>>  	struct gpio_desc		*powerdown_gpio;
>> -	unsigned int	gain;
>> +	struct gpio_desc		*gain_gpio;
>> +	struct gpio_desc		*filter_gpio;
>> +	unsigned int			gain;
>> +	unsigned int			odr;
>> +	unsigned int			int_vref_mv;
>>
>>  	struct ad_sigma_delta sd;
>>  };
>> @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
>>  		voltage_uv = regulator_get_voltage(st->reg);
>>  		if (voltage_uv < 0)
>>  			return voltage_uv;
>> -		*val = (voltage_uv / 1000) * st->gain;
>> +		voltage_uv /= 1000;
>> +		*val = voltage_uv * st->gain;
>>  		*val2 = chan->scan_type.realbits - 1;
>> +		st->int_vref_mv = voltage_uv;
>>  		return IIO_VAL_FRACTIONAL_LOG2;
>>  	case IIO_CHAN_INFO_OFFSET:
>>  		*val = -(1 << (chan->scan_type.realbits - 1));
>>  		return IIO_VAL_INT;
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		*val = st->odr;
>> +		return IIO_VAL_INT;
>>  	}
>>
>>  	return -EINVAL;
>>  }
>>
>> +static int ad7780_write_raw(struct iio_dev *indio_dev,
>> +			    struct iio_chan_spec const *chan,
>> +			    int val,
>> +			    int val2,
>> +			    long m)
>> +{
>> +	struct ad7780_state *st = iio_priv(indio_dev);
>> +	const struct ad7780_chip_info *chip_info = st->chip_info;
>> +	unsigned long long vref;
>> +	unsigned int full_scale, gain;
>> +
>> +	if (!chip_info->is_ad778x)
>> +		return 0;
>> +
>> +	switch (m) {
>> +	case IIO_CHAN_INFO_SCALE:
>> +		if (val != 0)
>> +			return -EINVAL;
>> +
>> +		vref = st->int_vref_mv * 1000000LL;
>> +		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
>> +		gain = DIV_ROUND_CLOSEST(vref, full_scale);
>> +		gain = DIV_ROUND_CLOSEST(gain, val2);
>> +		st->gain = gain;
>> +		if (gain < AD7780_GAIN_MIDPOINT)
>> +			gain = 0;
>> +		else
>> +			gain = 1;
>> +		gpiod_set_value(st->gain_gpio, gain);
>> +	break;
>> +	case IIO_CHAN_INFO_SAMP_FREQ:
>> +		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
>> +			val = 0;
>> +		else
>> +			val = 1;
>> +		st->odr = ad778x_odr_avail[val];
>> +		gpiod_set_value(st->filter_gpio, val);
>> +	break;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>>  static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
>>  				     unsigned int raw_sample)
>>  {
>> @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
>>  		return -EIO;
>>
>>  	if (chip_info->is_ad778x) {
>> -		if (raw_sample & AD7780_GAIN)
>> -			st->gain = 1;
>> -		else
>> -			st->gain = 128;
>> +		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
>> +		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
>>  	}
>>
>>  	return 0;
>> @@ -173,6 +232,7 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
>>
>>  static const struct iio_info ad7780_info = {
>>  	.read_raw = ad7780_read_raw,
>> +	.write_raw = ad7780_write_raw,
>>  };
>>
>>  static int ad7780_probe(struct spi_device *spi)
>> @@ -222,6 +282,29 @@ static int ad7780_probe(struct spi_device *spi)
>>  		goto error_disable_reg;
>>  	}
>>
>> +	if (st->chip_info->is_ad778x) {
>> +		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
>> +							"gain",
>
>These are not particularly standard names (basically not "reset"),
>so they should be vendor prefixed, so that people know to go
>look at the device specific binding.

I see. Should they be something like "adi,gain" and "adi,filter"? Am I
correct to assume that I'll have to somehow mention these in the
dt-binding?
>
>> +							GPIOD_OUT_HIGH);
>> +		if (IS_ERR(st->gain_gpio)) {
>> +			ret = PTR_ERR(st->gain_gpio);
>> +			dev_err(&spi->dev, "Failed to request gain GPIO: %d\n",
>> +				ret);
>> +			goto error_disable_reg;
>> +		}
>> +
>> +		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
>> +							  "filter",
>> +							  GPIOD_OUT_HIGH);
>> +		if (IS_ERR(st->filter_gpio)) {
>> +			ret = PTR_ERR(st->filter_gpio);
>> +			dev_err(&spi->dev,
>> +				"Failed to request filter GPIO: %d\n",
>> +				ret);
>> +			goto error_disable_reg;
>> +		}
>> +	}
>> +
>>  	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
>>  	if (ret)
>>  		goto error_disable_reg;
>
Jonathan Cameron Feb. 18, 2019, 2:48 p.m. UTC | #5
On Thu, 14 Feb 2019 18:31:12 -0200
Renato Lui Geh <renatogeh@gmail.com> wrote:

> Hi Jonathan,
> 
> Thanks for the review. Comments inline.
> 
> Renato
> 
> On 02/09, Jonathan Cameron wrote:
> >On Tue, 5 Feb 2019 15:13:00 -0200
> >Renato Lui Geh <renatogeh@gmail.com> wrote:
> >  
> >> Previously, the AD7780 driver only supported gpio for the 'powerdown'
> >> pin. This commit adds suppport for the 'gain' and 'filter' pin.
> >>
> >> Signed-off-by: Renato Lui Geh <renatogeh@gmail.com>
> >> Signed-off-by: Giuliano Belinassi <giuliano.belinassi@usp.br>
> >> Co-developed-by: Giuliano Belinassi <giuliano.belinassi@usp.br>  
> >Comments inline.
> >  
> >> ---
> >> Changes in v3:
> >> 	- Renamed ad7780_chip_info's filter to odr
> >> 	- Renamed ad778x_filter to ad778x_odr_avail
> >> 	- Changed vref variable from unsigned int to unsigned long long to
> >> 	  avoid overflow
> >> 	- Removed unnecessary AD_SD_CHANNEL macro
> >>
> >>  drivers/staging/iio/adc/ad7780.c | 95 ++++++++++++++++++++++++++++++--
> >>  1 file changed, 89 insertions(+), 6 deletions(-)
> >>
> >> diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
> >> index c4a85789c2db..6e4357800d31 100644
> >> --- a/drivers/staging/iio/adc/ad7780.c
> >> +++ b/drivers/staging/iio/adc/ad7780.c
> >> @@ -39,6 +39,15 @@
> >>  #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
> >>  #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
> >>
> >> +#define AD7780_GAIN_GPIO	0
> >> +#define AD7780_FILTER_GPIO	1  
> >What are these for?  
> 
> Sorry about that. That's leftover from a previous attempt.
> >  
> >> +
> >> +#define AD7780_GAIN_MIDPOINT	64
> >> +#define AD7780_FILTER_MIDPOINT	13350
> >> +
> >> +static const unsigned int ad778x_gain[2]      = { 1, 128 };
> >> +static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
> >> +
> >>  struct ad7780_chip_info {
> >>  	struct iio_chan_spec	channel;
> >>  	unsigned int		pattern_mask;
> >> @@ -50,7 +59,11 @@ struct ad7780_state {
> >>  	const struct ad7780_chip_info	*chip_info;
> >>  	struct regulator		*reg;
> >>  	struct gpio_desc		*powerdown_gpio;
> >> -	unsigned int	gain;
> >> +	struct gpio_desc		*gain_gpio;
> >> +	struct gpio_desc		*filter_gpio;
> >> +	unsigned int			gain;
> >> +	unsigned int			odr;
> >> +	unsigned int			int_vref_mv;
> >>
> >>  	struct ad_sigma_delta sd;
> >>  };
> >> @@ -104,17 +117,65 @@ static int ad7780_read_raw(struct iio_dev *indio_dev,
> >>  		voltage_uv = regulator_get_voltage(st->reg);
> >>  		if (voltage_uv < 0)
> >>  			return voltage_uv;
> >> -		*val = (voltage_uv / 1000) * st->gain;
> >> +		voltage_uv /= 1000;
> >> +		*val = voltage_uv * st->gain;
> >>  		*val2 = chan->scan_type.realbits - 1;
> >> +		st->int_vref_mv = voltage_uv;
> >>  		return IIO_VAL_FRACTIONAL_LOG2;
> >>  	case IIO_CHAN_INFO_OFFSET:
> >>  		*val = -(1 << (chan->scan_type.realbits - 1));
> >>  		return IIO_VAL_INT;
> >> +	case IIO_CHAN_INFO_SAMP_FREQ:
> >> +		*val = st->odr;
> >> +		return IIO_VAL_INT;
> >>  	}
> >>
> >>  	return -EINVAL;
> >>  }
> >>
> >> +static int ad7780_write_raw(struct iio_dev *indio_dev,
> >> +			    struct iio_chan_spec const *chan,
> >> +			    int val,
> >> +			    int val2,
> >> +			    long m)
> >> +{
> >> +	struct ad7780_state *st = iio_priv(indio_dev);
> >> +	const struct ad7780_chip_info *chip_info = st->chip_info;
> >> +	unsigned long long vref;
> >> +	unsigned int full_scale, gain;
> >> +
> >> +	if (!chip_info->is_ad778x)
> >> +		return 0;
> >> +
> >> +	switch (m) {
> >> +	case IIO_CHAN_INFO_SCALE:
> >> +		if (val != 0)
> >> +			return -EINVAL;
> >> +
> >> +		vref = st->int_vref_mv * 1000000LL;
> >> +		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
> >> +		gain = DIV_ROUND_CLOSEST(vref, full_scale);
> >> +		gain = DIV_ROUND_CLOSEST(gain, val2);
> >> +		st->gain = gain;
> >> +		if (gain < AD7780_GAIN_MIDPOINT)
> >> +			gain = 0;
> >> +		else
> >> +			gain = 1;
> >> +		gpiod_set_value(st->gain_gpio, gain);
> >> +	break;
> >> +	case IIO_CHAN_INFO_SAMP_FREQ:
> >> +		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
> >> +			val = 0;
> >> +		else
> >> +			val = 1;
> >> +		st->odr = ad778x_odr_avail[val];
> >> +		gpiod_set_value(st->filter_gpio, val);
> >> +	break;
> >> +	}
> >> +
> >> +	return 0;
> >> +}
> >> +
> >>  static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> >>  				     unsigned int raw_sample)
> >>  {
> >> @@ -126,10 +187,8 @@ static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
> >>  		return -EIO;
> >>
> >>  	if (chip_info->is_ad778x) {
> >> -		if (raw_sample & AD7780_GAIN)
> >> -			st->gain = 1;
> >> -		else
> >> -			st->gain = 128;
> >> +		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
> >> +		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
> >>  	}
> >>
> >>  	return 0;
> >> @@ -173,6 +232,7 @@ static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
> >>
> >>  static const struct iio_info ad7780_info = {
> >>  	.read_raw = ad7780_read_raw,
> >> +	.write_raw = ad7780_write_raw,
> >>  };
> >>
> >>  static int ad7780_probe(struct spi_device *spi)
> >> @@ -222,6 +282,29 @@ static int ad7780_probe(struct spi_device *spi)
> >>  		goto error_disable_reg;
> >>  	}
> >>
> >> +	if (st->chip_info->is_ad778x) {
> >> +		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
> >> +							"gain",  
> >
> >These are not particularly standard names (basically not "reset"),
> >so they should be vendor prefixed, so that people know to go
> >look at the device specific binding.  
> 
> I see. Should they be something like "adi,gain" and "adi,filter"? Am I
> correct to assume that I'll have to somehow mention these in the
> dt-binding?
yes and yes - name is just adi,gain-gpios rather than gain-gpios.

Take a look at the other drivers doing the same thing.  We used to
be more lax on this so there are drivers without the prefixes, but
can't fix them now.

Jonathan

> >  
> >> +							GPIOD_OUT_HIGH);
> >> +		if (IS_ERR(st->gain_gpio)) {
> >> +			ret = PTR_ERR(st->gain_gpio);
> >> +			dev_err(&spi->dev, "Failed to request gain GPIO: %d\n",
> >> +				ret);
> >> +			goto error_disable_reg;
> >> +		}
> >> +
> >> +		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
> >> +							  "filter",
> >> +							  GPIOD_OUT_HIGH);
> >> +		if (IS_ERR(st->filter_gpio)) {
> >> +			ret = PTR_ERR(st->filter_gpio);
> >> +			dev_err(&spi->dev,
> >> +				"Failed to request filter GPIO: %d\n",
> >> +				ret);
> >> +			goto error_disable_reg;
> >> +		}
> >> +	}
> >> +
> >>  	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
> >>  	if (ret)
> >>  		goto error_disable_reg;  
> >
diff mbox series

Patch

diff --git a/drivers/staging/iio/adc/ad7780.c b/drivers/staging/iio/adc/ad7780.c
index c4a85789c2db..6e4357800d31 100644
--- a/drivers/staging/iio/adc/ad7780.c
+++ b/drivers/staging/iio/adc/ad7780.c
@@ -39,6 +39,15 @@ 
 #define AD7170_PATTERN		(AD7780_PAT0 | AD7170_PAT2)
 #define AD7170_PATTERN_MASK	(AD7780_PAT0 | AD7780_PAT1 | AD7170_PAT2)
 
+#define AD7780_GAIN_GPIO	0
+#define AD7780_FILTER_GPIO	1
+
+#define AD7780_GAIN_MIDPOINT	64
+#define AD7780_FILTER_MIDPOINT	13350
+
+static const unsigned int ad778x_gain[2]      = { 1, 128 };
+static const unsigned int ad778x_odr_avail[2] = { 10000, 16700 };
+
 struct ad7780_chip_info {
 	struct iio_chan_spec	channel;
 	unsigned int		pattern_mask;
@@ -50,7 +59,11 @@  struct ad7780_state {
 	const struct ad7780_chip_info	*chip_info;
 	struct regulator		*reg;
 	struct gpio_desc		*powerdown_gpio;
-	unsigned int	gain;
+	struct gpio_desc		*gain_gpio;
+	struct gpio_desc		*filter_gpio;
+	unsigned int			gain;
+	unsigned int			odr;
+	unsigned int			int_vref_mv;
 
 	struct ad_sigma_delta sd;
 };
@@ -104,17 +117,65 @@  static int ad7780_read_raw(struct iio_dev *indio_dev,
 		voltage_uv = regulator_get_voltage(st->reg);
 		if (voltage_uv < 0)
 			return voltage_uv;
-		*val = (voltage_uv / 1000) * st->gain;
+		voltage_uv /= 1000;
+		*val = voltage_uv * st->gain;
 		*val2 = chan->scan_type.realbits - 1;
+		st->int_vref_mv = voltage_uv;
 		return IIO_VAL_FRACTIONAL_LOG2;
 	case IIO_CHAN_INFO_OFFSET:
 		*val = -(1 << (chan->scan_type.realbits - 1));
 		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = st->odr;
+		return IIO_VAL_INT;
 	}
 
 	return -EINVAL;
 }
 
+static int ad7780_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val,
+			    int val2,
+			    long m)
+{
+	struct ad7780_state *st = iio_priv(indio_dev);
+	const struct ad7780_chip_info *chip_info = st->chip_info;
+	unsigned long long vref;
+	unsigned int full_scale, gain;
+
+	if (!chip_info->is_ad778x)
+		return 0;
+
+	switch (m) {
+	case IIO_CHAN_INFO_SCALE:
+		if (val != 0)
+			return -EINVAL;
+
+		vref = st->int_vref_mv * 1000000LL;
+		full_scale = 1 << (chip_info->channel.scan_type.realbits - 1);
+		gain = DIV_ROUND_CLOSEST(vref, full_scale);
+		gain = DIV_ROUND_CLOSEST(gain, val2);
+		st->gain = gain;
+		if (gain < AD7780_GAIN_MIDPOINT)
+			gain = 0;
+		else
+			gain = 1;
+		gpiod_set_value(st->gain_gpio, gain);
+	break;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (1000*val + val2/1000 < AD7780_FILTER_MIDPOINT)
+			val = 0;
+		else
+			val = 1;
+		st->odr = ad778x_odr_avail[val];
+		gpiod_set_value(st->filter_gpio, val);
+	break;
+	}
+
+	return 0;
+}
+
 static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
 				     unsigned int raw_sample)
 {
@@ -126,10 +187,8 @@  static int ad7780_postprocess_sample(struct ad_sigma_delta *sigma_delta,
 		return -EIO;
 
 	if (chip_info->is_ad778x) {
-		if (raw_sample & AD7780_GAIN)
-			st->gain = 1;
-		else
-			st->gain = 128;
+		st->gain = ad778x_gain[raw_sample & AD7780_GAIN];
+		st->odr = ad778x_odr_avail[raw_sample & AD7780_FILTER];
 	}
 
 	return 0;
@@ -173,6 +232,7 @@  static const struct ad7780_chip_info ad7780_chip_info_tbl[] = {
 
 static const struct iio_info ad7780_info = {
 	.read_raw = ad7780_read_raw,
+	.write_raw = ad7780_write_raw,
 };
 
 static int ad7780_probe(struct spi_device *spi)
@@ -222,6 +282,29 @@  static int ad7780_probe(struct spi_device *spi)
 		goto error_disable_reg;
 	}
 
+	if (st->chip_info->is_ad778x) {
+		st->gain_gpio = devm_gpiod_get_optional(&spi->dev,
+							"gain",
+							GPIOD_OUT_HIGH);
+		if (IS_ERR(st->gain_gpio)) {
+			ret = PTR_ERR(st->gain_gpio);
+			dev_err(&spi->dev, "Failed to request gain GPIO: %d\n",
+				ret);
+			goto error_disable_reg;
+		}
+
+		st->filter_gpio = devm_gpiod_get_optional(&spi->dev,
+							  "filter",
+							  GPIOD_OUT_HIGH);
+		if (IS_ERR(st->filter_gpio)) {
+			ret = PTR_ERR(st->filter_gpio);
+			dev_err(&spi->dev,
+				"Failed to request filter GPIO: %d\n",
+				ret);
+			goto error_disable_reg;
+		}
+	}
+
 	ret = ad_sd_setup_buffer_and_trigger(indio_dev);
 	if (ret)
 		goto error_disable_reg;