iio: gyro: itg3200 switch sampling frequency attr to core support.

By using the info_mask_shared_by_all element of the channel spec, access
to the sampling frequency becomes available to in kernel users of the
driver.  It also shortens and simplifies the code a little.

Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Cc: Manuel Stahl <manuel.stahl@iis.fraunhofer.de>
Cc: Thorsten Nowak <thorsten.nowak@iis.fraunhofer.de>
Cc: Christian Strobel <christian.strobel@iis.fraunhofer.de>

drivers/iio/gyro/itg3200_core.c

@@ -90,6 +90,7 @@ static int itg3200_read_raw(struct iio_dev *indio_dev,
 {
 	int ret = 0;
 	u8 reg;
+	u8 regval;
 
 	switch (info) {
 	case IIO_CHAN_INFO_RAW:
@@ -107,65 +108,60 @@ static int itg3200_read_raw(struct iio_dev *indio_dev,
 		/* Only the temperature channel has an offset */
 		*val = 23000;
 		return IIO_VAL_INT;
-	default:
-		return -EINVAL;
-	}
-}
-
-static ssize_t itg3200_read_frequency(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	int ret, sps;
-	u8 val;
-
-	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &val);
-	if (ret)
-		return ret;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &regval);
+		if (ret)
+			return ret;
 
-	sps = (val & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
+		*val = (regval & ITG3200_DLPF_CFG_MASK) ? 1000 : 8000;
 
-	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, &val);
-	if (ret)
-		return ret;
+		ret = itg3200_read_reg_8(indio_dev,
+					 ITG3200_REG_SAMPLE_RATE_DIV,
+					 &regval);
+		if (ret)
+			return ret;
 
-	sps /= val + 1;
+		*val /= regval + 1;
+		return IIO_VAL_INT;
 
-	return sprintf(buf, "%d\n", sps);
+	default:
+		return -EINVAL;
+	}
 }
 
-static ssize_t itg3200_write_frequency(struct device *dev,
-		struct device_attribute *attr,
-		const char *buf,
-		size_t len)
+static int itg3200_write_raw(struct iio_dev *indio_dev,
+			     struct iio_chan_spec const *chan,
+			     int val,
+			     int val2,
+			     long mask)
 {
-	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
-	unsigned val;
 	int ret;
 	u8 t;
 
-	ret = kstrtouint(buf, 10, &val);
-	if (ret)
-		return ret;
+	switch (mask) {
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val == 0 || val2 != 0)
+			return -EINVAL;
 
-	mutex_lock(&indio_dev->mlock);
+		mutex_lock(&indio_dev->mlock);
 
-	ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
-	if (ret)
-		goto err_ret;
+		ret = itg3200_read_reg_8(indio_dev, ITG3200_REG_DLPF, &t);
+		if (ret) {
+			mutex_unlock(&indio_dev->mlock);
+			return ret;
+		}
+		t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
 
-	if (val == 0) {
-		ret = -EINVAL;
-		goto err_ret;
-	}
-	t = ((t & ITG3200_DLPF_CFG_MASK) ? 1000u : 8000u) / val - 1;
+		ret = itg3200_write_reg_8(indio_dev,
+					  ITG3200_REG_SAMPLE_RATE_DIV,
+					  t);
 
-	ret = itg3200_write_reg_8(indio_dev, ITG3200_REG_SAMPLE_RATE_DIV, t);
-
-err_ret:
-	mutex_unlock(&indio_dev->mlock);
+		mutex_unlock(&indio_dev->mlock);
+	return ret;
 
-	return ret ? ret : len;
+	default:
+		return -EINVAL;
+	}
 }
 
 /*
@@ -255,6 +251,7 @@ err_ret:
 	.channel2 = IIO_MOD_ ## _mod, \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
 	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
+	.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), \
 	.address = ITG3200_REG_GYRO_ ## _mod ## OUT_H, \
 	.scan_index = ITG3200_SCAN_GYRO_ ## _mod, \
 	.scan_type = ITG3200_ST, \
@@ -267,6 +264,7 @@ static const struct iio_chan_spec itg3200_channels[] = {
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
 		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OFFSET) |
 		BIT(IIO_CHAN_INFO_SCALE),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.address = ITG3200_REG_TEMP_OUT_H,
 		.scan_index = ITG3200_SCAN_TEMP,
 		.scan_type = ITG3200_ST,
@@ -277,22 +275,9 @@ static const struct iio_chan_spec itg3200_channels[] = {
 	IIO_CHAN_SOFT_TIMESTAMP(ITG3200_SCAN_ELEMENTS),
 };
 
-/* IIO device attributes */
-static IIO_DEV_ATTR_SAMP_FREQ(S_IWUSR | S_IRUGO, itg3200_read_frequency,
-		itg3200_write_frequency);
-
-static struct attribute *itg3200_attributes[] = {
-	&iio_dev_attr_sampling_frequency.dev_attr.attr,
-	NULL
-};
-
-static const struct attribute_group itg3200_attribute_group = {
-	.attrs = itg3200_attributes,
-};
-
 static const struct iio_info itg3200_info = {
-	.attrs = &itg3200_attribute_group,
 	.read_raw = &itg3200_read_raw,
+	.write_raw = &itg3200_write_raw,
 	.driver_module = THIS_MODULE,
 };