diff mbox series

[v2,3/4] iio: adc: lpc32xx: Add scale feature

Message ID 20190315095231.17001-4-gregory.clement@bootlin.com (mailing list archive)
State New, archived
Headers show
Series Adding scale support to the lpc32xx ADC driver | expand

Commit Message

Gregory CLEMENT March 15, 2019, 9:52 a.m. UTC 
Until now this driver only exposed the raw value of the channels. With
this patch, the scale value is also exposed.

It depends of a regulator supply, and unlike most of the other driver, do
not having this regulator won't prevent to use the driver. The reason for
it is to allow to continue to use this driver with an old device tree. If
there is no regulator supply then the scale won't be exposed.

Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
---
 drivers/iio/adc/lpc32xx_adc.c | 44 ++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 6 deletions(-)

Comments

Jonathan Cameron March 16, 2019, 5:26 p.m. UTC | #1 
On Fri, 15 Mar 2019 10:52:30 +0100
Gregory CLEMENT <gregory.clement@bootlin.com> wrote:

> Until now this driver only exposed the raw value of the channels. With
> this patch, the scale value is also exposed.
> 
> It depends of a regulator supply, and unlike most of the other driver, do
> not having this regulator won't prevent to use the driver. The reason for
> it is to allow to continue to use this driver with an old device tree. If
> there is no regulator supply then the scale won't be exposed.
> 
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

I made a minor tweak to downgrade the message if the regulator isn't
specified.

Applied to the togreg branch of iio.git and pushed out as testing
for the autobuilders to play with it.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/lpc32xx_adc.c | 44 ++++++++++++++++++++++++++++++-----
>  1 file changed, 38 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
> index f391c1e10136..5d1c76e3aad8 100644
> --- a/drivers/iio/adc/lpc32xx_adc.c
> +++ b/drivers/iio/adc/lpc32xx_adc.c
> @@ -14,6 +14,7 @@
>  #include <linux/io.h>
>  #include <linux/module.h>
>  #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
>  
>  /*
>   * LPC32XX registers definitions
> @@ -45,6 +46,7 @@ struct lpc32xx_adc_state {
>  	void __iomem *adc_base;
>  	struct clk *clk;
>  	struct completion completion;
> +	struct regulator *vref;
>  
>  	u32 value;
>  };
> @@ -57,7 +59,9 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,
>  {
>  	struct lpc32xx_adc_state *st = iio_priv(indio_dev);
>  	int ret;
> -	if (mask == IIO_CHAN_INFO_RAW) {
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
>  		mutex_lock(&indio_dev->mlock);
>  		ret = clk_prepare_enable(st->clk);
>  		if (ret) {
> @@ -77,22 +81,36 @@ static int lpc32xx_read_raw(struct iio_dev *indio_dev,
>  		mutex_unlock(&indio_dev->mlock);
>  
>  		return IIO_VAL_INT;
> -	}
>  
> -	return -EINVAL;
> +	case IIO_CHAN_INFO_SCALE:
> +		*val = regulator_get_voltage(st->vref) / 1000;
> +		*val2 =  10;
> +
> +		return IIO_VAL_FRACTIONAL_LOG2;
> +	default:
> +		return -EINVAL;
> +	}
>  }
>  
>  static const struct iio_info lpc32xx_adc_iio_info = {
>  	.read_raw = &lpc32xx_read_raw,
>  };
>  
> -#define LPC32XX_ADC_CHANNEL(_index) {			\
> +#define LPC32XX_ADC_CHANNEL_BASE(_index)		\
>  	.type = IIO_VOLTAGE,				\
>  	.indexed = 1,					\
>  	.channel = _index,				\
>  	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
>  	.address = LPC32XXAD_IN * _index,		\
> -	.scan_index = _index,				\
> +	.scan_index = _index,
> +
> +#define LPC32XX_ADC_CHANNEL(_index) {		\
> +	LPC32XX_ADC_CHANNEL_BASE(_index)	\
> +}
> +
> +#define LPC32XX_ADC_SCALE_CHANNEL(_index) {			\
> +	LPC32XX_ADC_CHANNEL_BASE(_index)			\
> +	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)	\
>  }
>  
>  static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
> @@ -101,6 +119,12 @@ static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
>  	LPC32XX_ADC_CHANNEL(2),
>  };
>  
> +static const struct iio_chan_spec lpc32xx_adc_iio_scale_channels[] = {
> +	LPC32XX_ADC_SCALE_CHANNEL(0),
> +	LPC32XX_ADC_SCALE_CHANNEL(1),
> +	LPC32XX_ADC_SCALE_CHANNEL(2),
> +};
> +
>  static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
>  {
>  	struct lpc32xx_adc_state *st = dev_id;
> @@ -159,6 +183,15 @@ static int lpc32xx_adc_probe(struct platform_device *pdev)
>  		return retval;
>  	}
>  
> +	st->vref = devm_regulator_get(&pdev->dev, "vref");
> +	if (IS_ERR(st->vref)) {
> +		iodev->channels = lpc32xx_adc_iio_channels;
> +		dev_err(&pdev->dev,
> +			"Missing vref regulator: No scaling available\n");
It isn't an error, so downgraded to dev_info.

> +	} else {
> +		iodev->channels = lpc32xx_adc_iio_scale_channels;
> +	}
> +
>  	platform_set_drvdata(pdev, iodev);
>  
>  	init_completion(&st->completion);
> @@ -167,7 +200,6 @@ static int lpc32xx_adc_probe(struct platform_device *pdev)
>  	iodev->dev.parent = &pdev->dev;
>  	iodev->info = &lpc32xx_adc_iio_info;
>  	iodev->modes = INDIO_DIRECT_MODE;
> -	iodev->channels = lpc32xx_adc_iio_channels;
>  	iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
>  
>  	retval = devm_iio_device_register(&pdev->dev, iodev);
diff mbox series

Patch

diff --git a/drivers/iio/adc/lpc32xx_adc.c b/drivers/iio/adc/lpc32xx_adc.c
index f391c1e10136..5d1c76e3aad8 100644
--- a/drivers/iio/adc/lpc32xx_adc.c
+++ b/drivers/iio/adc/lpc32xx_adc.c
@@ -14,6 +14,7 @@ 
 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 
 /*
  * LPC32XX registers definitions
@@ -45,6 +46,7 @@  struct lpc32xx_adc_state {
 	void __iomem *adc_base;
 	struct clk *clk;
 	struct completion completion;
+	struct regulator *vref;
 
 	u32 value;
 };
@@ -57,7 +59,9 @@  static int lpc32xx_read_raw(struct iio_dev *indio_dev,
 {
 	struct lpc32xx_adc_state *st = iio_priv(indio_dev);
 	int ret;
-	if (mask == IIO_CHAN_INFO_RAW) {
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&indio_dev->mlock);
 		ret = clk_prepare_enable(st->clk);
 		if (ret) {
@@ -77,22 +81,36 @@  static int lpc32xx_read_raw(struct iio_dev *indio_dev,
 		mutex_unlock(&indio_dev->mlock);
 
 		return IIO_VAL_INT;
-	}
 
-	return -EINVAL;
+	case IIO_CHAN_INFO_SCALE:
+		*val = regulator_get_voltage(st->vref) / 1000;
+		*val2 =  10;
+
+		return IIO_VAL_FRACTIONAL_LOG2;
+	default:
+		return -EINVAL;
+	}
 }
 
 static const struct iio_info lpc32xx_adc_iio_info = {
 	.read_raw = &lpc32xx_read_raw,
 };
 
-#define LPC32XX_ADC_CHANNEL(_index) {			\
+#define LPC32XX_ADC_CHANNEL_BASE(_index)		\
 	.type = IIO_VOLTAGE,				\
 	.indexed = 1,					\
 	.channel = _index,				\
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
 	.address = LPC32XXAD_IN * _index,		\
-	.scan_index = _index,				\
+	.scan_index = _index,
+
+#define LPC32XX_ADC_CHANNEL(_index) {		\
+	LPC32XX_ADC_CHANNEL_BASE(_index)	\
+}
+
+#define LPC32XX_ADC_SCALE_CHANNEL(_index) {			\
+	LPC32XX_ADC_CHANNEL_BASE(_index)			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)	\
 }
 
 static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
@@ -101,6 +119,12 @@  static const struct iio_chan_spec lpc32xx_adc_iio_channels[] = {
 	LPC32XX_ADC_CHANNEL(2),
 };
 
+static const struct iio_chan_spec lpc32xx_adc_iio_scale_channels[] = {
+	LPC32XX_ADC_SCALE_CHANNEL(0),
+	LPC32XX_ADC_SCALE_CHANNEL(1),
+	LPC32XX_ADC_SCALE_CHANNEL(2),
+};
+
 static irqreturn_t lpc32xx_adc_isr(int irq, void *dev_id)
 {
 	struct lpc32xx_adc_state *st = dev_id;
@@ -159,6 +183,15 @@  static int lpc32xx_adc_probe(struct platform_device *pdev)
 		return retval;
 	}
 
+	st->vref = devm_regulator_get(&pdev->dev, "vref");
+	if (IS_ERR(st->vref)) {
+		iodev->channels = lpc32xx_adc_iio_channels;
+		dev_err(&pdev->dev,
+			"Missing vref regulator: No scaling available\n");
+	} else {
+		iodev->channels = lpc32xx_adc_iio_scale_channels;
+	}
+
 	platform_set_drvdata(pdev, iodev);
 
 	init_completion(&st->completion);
@@ -167,7 +200,6 @@  static int lpc32xx_adc_probe(struct platform_device *pdev)
 	iodev->dev.parent = &pdev->dev;
 	iodev->info = &lpc32xx_adc_iio_info;
 	iodev->modes = INDIO_DIRECT_MODE;
-	iodev->channels = lpc32xx_adc_iio_channels;
 	iodev->num_channels = ARRAY_SIZE(lpc32xx_adc_iio_channels);
 
 	retval = devm_iio_device_register(&pdev->dev, iodev);