iio: vcnl4000: Add sampling frequency support for VCNL4010/20.

Add sampling frequency support for proximity data on VCNL4010 and VCNL4020
chips.
Signed-off-by: Mathieu Othacehe <m.othacehe@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/vcnl4000.c

@@ -86,6 +86,16 @@
 #define VCNL4010_INT_DRDY \
 	(BIT(VCNL4010_INT_PROXIMITY) | BIT(VCNL4010_INT_ALS))
 
+static const int vcnl4010_prox_sampling_frequency[][2] = {
+	{1, 950000},
+	{3, 906250},
+	{7, 812500},
+	{16, 625000},
+	{31, 250000},
+	{62, 500000},
+	{125, 0},
+	{250, 0},
+};
 
 #define VCNL4000_SLEEP_DELAY_MS	2000 /* before we enter pm_runtime_suspend */
 
@@ -364,6 +374,24 @@ static int vcnl4200_measure_proximity(struct vcnl4000_data *data, int *val)
 	return vcnl4200_measure(data, &data->vcnl4200_ps, val);
 }
 
+static int vcnl4010_read_proxy_samp_freq(struct vcnl4000_data *data, int *val,
+					 int *val2)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(data->client, VCNL4010_PROX_RATE);
+	if (ret < 0)
+		return ret;
+
+	if (ret >= ARRAY_SIZE(vcnl4010_prox_sampling_frequency))
+		return -EINVAL;
+
+	*val = vcnl4010_prox_sampling_frequency[ret][0];
+	*val2 = vcnl4010_prox_sampling_frequency[ret][1];
+
+	return 0;
+}
+
 static bool vcnl4010_is_in_periodic_mode(struct vcnl4000_data *data)
 {
 	int ret;
@@ -457,11 +485,95 @@ static int vcnl4010_read_raw(struct iio_dev *indio_dev,
 
 		iio_device_release_direct_mode(indio_dev);
 		return ret;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		switch (chan->type) {
+		case IIO_PROXIMITY:
+			ret = vcnl4010_read_proxy_samp_freq(data, val, val2);
+			if (ret < 0)
+				return ret;
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
 	default:
 		return -EINVAL;
 	}
 }
 
+static int vcnl4010_read_avail(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       const int **vals, int *type, int *length,
+			       long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*vals = (int *)vcnl4010_prox_sampling_frequency;
+		*type = IIO_VAL_INT_PLUS_MICRO;
+		*length = 2 * ARRAY_SIZE(vcnl4010_prox_sampling_frequency);
+		return IIO_AVAIL_LIST;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int vcnl4010_write_proxy_samp_freq(struct vcnl4000_data *data, int val,
+					  int val2)
+{
+	unsigned int i;
+	int index = -1;
+
+	for (i = 0; i < ARRAY_SIZE(vcnl4010_prox_sampling_frequency); i++) {
+		if (val == vcnl4010_prox_sampling_frequency[i][0] &&
+		    val2 == vcnl4010_prox_sampling_frequency[i][1]) {
+			index = i;
+			break;
+		}
+	}
+
+	if (index < 0)
+		return -EINVAL;
+
+	return i2c_smbus_write_byte_data(data->client, VCNL4010_PROX_RATE,
+					 index);
+}
+
+static int vcnl4010_write_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int val, int val2, long mask)
+{
+	int ret;
+	struct vcnl4000_data *data = iio_priv(indio_dev);
+
+	ret = iio_device_claim_direct_mode(indio_dev);
+	if (ret)
+		return ret;
+
+	/* Protect against event capture. */
+	if (vcnl4010_is_in_periodic_mode(data)) {
+		ret = -EBUSY;
+		goto end;
+	}
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		switch (chan->type) {
+		case IIO_PROXIMITY:
+			ret = vcnl4010_write_proxy_samp_freq(data, val, val2);
+			goto end;
+		default:
+			ret = -EINVAL;
+			goto end;
+		}
+	default:
+		ret = -EINVAL;
+		goto end;
+	}
+
+end:
+	iio_device_release_direct_mode(indio_dev);
+	return ret;
+}
+
 static int vcnl4010_read_event(struct iio_dev *indio_dev,
 			       const struct iio_chan_spec *chan,
 			       enum iio_event_type type,
@@ -664,7 +776,9 @@ static const struct iio_chan_spec vcnl4010_channels[] = {
 			BIT(IIO_CHAN_INFO_SCALE),
 	}, {
 		.type = IIO_PROXIMITY,
-		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+			BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.info_mask_separate_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.event_spec = vcnl4000_event_spec,
 		.num_event_specs = ARRAY_SIZE(vcnl4000_event_spec),
 		.ext_info = vcnl4000_ext_info,
@@ -677,6 +791,8 @@ static const struct iio_info vcnl4000_info = {
 
 static const struct iio_info vcnl4010_info = {
 	.read_raw = vcnl4010_read_raw,
+	.read_avail = vcnl4010_read_avail,
+	.write_raw = vcnl4010_write_raw,
 	.read_event_value = vcnl4010_read_event,
 	.write_event_value = vcnl4010_write_event,
 	.read_event_config = vcnl4010_read_event_config,