Commit 7dde2719 authored by David Lechner's avatar David Lechner Committed by Jonathan Cameron
Browse files

staging: iio: resolver: ad2s1210: convert fexcit to channel attribute 



The ad2s1210 driver has a device-specific attribute `fexcit` for setting
the frequency of the excitation output. This converts it to a channel in
order to use standard IIO ABI.

The excitation frequency is an analog output that generates a sine wave.
Only the frequency is configurable. According to the datasheet, the
specified range of the excitation frequency is from 2 kHz to 20 kHz and
can be set in increments of 250 Hz.

Signed-off-by: default avatarDavid Lechner <dlechner@baylibre.com>
Link: https://lore.kernel.org/r/20231005-ad2s1210-mainline-v4-3-ec00746840fc@baylibre.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent bae02376

drivers/staging/iio/resolver/ad2s1210.c

+71 −52
Original line number Diff line number Diff line
@@ -227,54 +227,6 @@ static int ad2s1210_set_resolution_gpios(struct ad2s1210_state *st, 
				     bitmap);

}



static ssize_t ad2s1210_show_fexcit(struct device *dev,

				    struct device_attribute *attr,

				    char *buf)

{

	struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));

	unsigned int value;

	u16 fexcit;

	int ret;



	mutex_lock(&st->lock);

	ret = regmap_read(st->regmap, AD2S1210_REG_EXCIT_FREQ, &value);

	if (ret < 0)

		goto error_ret;



	fexcit = value * st->clkin_hz / (1 << 15);



	ret = sprintf(buf, "%u\n", fexcit);



error_ret:

	mutex_unlock(&st->lock);

	return ret;

}



static ssize_t ad2s1210_store_fexcit(struct device *dev,

				     struct device_attribute *attr,

				     const char *buf, size_t len)

{

	struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));

	u16 fexcit;

	int ret;



	ret = kstrtou16(buf, 10, &fexcit);

	if (ret < 0 || fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT)

		return -EINVAL;



	mutex_lock(&st->lock);

	ret = ad2s1210_reinit_excitation_frequency(st, fexcit);

	if (ret < 0)

		goto error_ret;



	ret = len;



error_ret:

	mutex_unlock(&st->lock);



	return ret;

}



static ssize_t ad2s1210_show_resolution(struct device *dev,

					struct device_attribute *attr,

					char *buf)
@@ -478,6 +430,38 @@ static int ad2s1210_set_hysteresis(struct ad2s1210_state *st, int val) 
	return ret;

}



static int ad2s1210_get_excitation_frequency(struct ad2s1210_state *st, int *val)

{

	unsigned int reg_val;

	int ret;



	mutex_lock(&st->lock);

	ret = regmap_read(st->regmap, AD2S1210_REG_EXCIT_FREQ, &reg_val);

	if (ret < 0)

		goto error_ret;



	*val = reg_val * st->clkin_hz / (1 << 15);

	ret = IIO_VAL_INT;



error_ret:

	mutex_unlock(&st->lock);

	return ret;

}



static int ad2s1210_set_excitation_frequency(struct ad2s1210_state *st, int val)

{

	int ret;



	if (val < AD2S1210_MIN_EXCIT || val > AD2S1210_MAX_EXCIT)

		return -EINVAL;



	mutex_lock(&st->lock);

	ret = ad2s1210_reinit_excitation_frequency(st, val);

	mutex_unlock(&st->lock);



	return ret;

}



static const int ad2s1210_velocity_scale[] = {

	17089132, /* 8.192MHz / (2*pi * 2500 / 2^15) */

	42722830, /* 8.192MHz / (2*pi * 1000 / 2^15) */
@@ -510,6 +494,13 @@ static int ad2s1210_read_raw(struct iio_dev *indio_dev, 
		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_FREQUENCY:

		switch (chan->type) {

		case IIO_ALTVOLTAGE:

			return ad2s1210_get_excitation_frequency(st, val);

		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_HYSTERESIS:

		switch (chan->type) {

		case IIO_ANGL:
@@ -527,9 +518,24 @@ static int ad2s1210_read_avail(struct iio_dev *indio_dev, 
			       const int **vals, int *type,

			       int *length, long mask)

{

	static const int excitation_frequency_available[] = {

		AD2S1210_MIN_EXCIT,

		250, /* step */

		AD2S1210_MAX_EXCIT,

	};



	struct ad2s1210_state *st = iio_priv(indio_dev);



	switch (mask) {

	case IIO_CHAN_INFO_FREQUENCY:

		switch (chan->type) {

		case IIO_ALTVOLTAGE:

			*type = IIO_VAL_INT;

			*vals = excitation_frequency_available;

			return IIO_AVAIL_RANGE;

		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_HYSTERESIS:

		switch (chan->type) {

		case IIO_ANGL:
@@ -552,6 +558,13 @@ static int ad2s1210_write_raw(struct iio_dev *indio_dev, 
	struct ad2s1210_state *st = iio_priv(indio_dev);



	switch (mask) {

	case IIO_CHAN_INFO_FREQUENCY:

		switch (chan->type) {

		case IIO_ALTVOLTAGE:

			return ad2s1210_set_excitation_frequency(st, val);

		default:

			return -EINVAL;

		}

	case IIO_CHAN_INFO_HYSTERESIS:

		switch (chan->type) {

		case IIO_ANGL:
@@ -564,8 +577,6 @@ static int ad2s1210_write_raw(struct iio_dev *indio_dev, 
	}

}



static IIO_DEVICE_ATTR(fexcit, 0644,

		       ad2s1210_show_fexcit,	ad2s1210_store_fexcit, 0);

static IIO_DEVICE_ATTR(bits, 0644,

		       ad2s1210_show_resolution, ad2s1210_store_resolution, 0);

static IIO_DEVICE_ATTR(fault, 0644,
@@ -609,11 +620,19 @@ static const struct iio_chan_spec ad2s1210_channels[] = { 
		.channel = 0,

		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |

				      BIT(IIO_CHAN_INFO_SCALE),

	}

	}, {

		/* excitation frequency output */

		.type = IIO_ALTVOLTAGE,

		.indexed = 1,

		.channel = 0,

		.output = 1,

		.scan_index = -1,

		.info_mask_separate = BIT(IIO_CHAN_INFO_FREQUENCY),

		.info_mask_separate_available = BIT(IIO_CHAN_INFO_FREQUENCY),

	},

};



static struct attribute *ad2s1210_attributes[] = {

	&iio_dev_attr_fexcit.dev_attr.attr,

	&iio_dev_attr_bits.dev_attr.attr,

	&iio_dev_attr_fault.dev_attr.attr,

	&iio_dev_attr_los_thrd.dev_attr.attr,