[PATCH v4 1/5] iio: core: Handle 'dB' suffix in core

Beniamin Bia
2020-01-29T14:21:40Z

This patch handles the db suffix used for writing micro db values.

Signed-off-by: Beniamin Bia <beniamin.bia@analog.com>
---
drivers/iio/industrialio-core.c | 35 ++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index 65ff0d067018..b70111837420 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -769,17 +769,18 @@ static ssize_t iio_read_channel_info_avail(struct device *dev,
}

/**
- * iio_str_to_fixpoint() - Parse a fixed-point number from a string
+ * __iio_str_to_fixpoint() - Parse a fixed-point number from a string
* @str: The string to parse
* @fract_mult: Multiplier for the first decimal place, should be a power of 10
* @integer: The integer part of the number
* @fract: The fractional part of the number
+ * @scale_db: True if this should parse as dB
*
* Returns 0 on success, or a negative error code if the string could not be
* parsed.
*/
-int iio_str_to_fixpoint(const char *str, int fract_mult,
- int *integer, int *fract)
+int __iio_str_to_fixpoint(const char *str, int fract_mult,
+ int *integer, int *fract, bool scale_db)
{
int i = 0, f = 0;
bool integer_part = true, negative = false;
@@ -810,6 +811,10 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
break;
else
return -EINVAL;
+ } else if (!strncmp(str, " dB", sizeof(" dB") - 1) && scale_db) {
+ /* Ignore the dB suffix */
+ str += sizeof(" dB") - 1;
+ continue;
} else if (*str == '.' && integer_part) {
integer_part = false;
} else {
@@ -832,6 +837,22 @@ int iio_str_to_fixpoint(const char *str, int fract_mult,
}
EXPORT_SYMBOL_GPL(iio_str_to_fixpoint);

+/**
+ * iio_str_to_fixpoint() - Parse a fixed-point number from a string
+ * @str: The string to parse
+ * @fract_mult: Multiplier for the first decimal place, should be a power of 10
+ * @integer: The integer part of the number
+ * @fract: The fractional part of the number
+ *
+ * Returns 0 on success, or a negative error code if the string could not be
+ * parsed.
+ */
+int iio_str_to_fixpoint(const char *str, int fract_mult,
+ int *integer, int *fract)
+{
+ return __iio_str_to_fixpoint(str, fract_mult, integer, fract, false);
+}
+
static ssize_t iio_write_channel_info(struct device *dev,
struct device_attribute *attr,
const char *buf,
@@ -842,6 +863,7 @@ static ssize_t iio_write_channel_info(struct device *dev,
int ret, fract_mult = 100000;
int integer, fract = 0;
bool is_char = false;
+ bool scale_db = false;

/* Assumes decimal - precision based on number of digits */
if (!indio_dev->info->write_raw)
@@ -853,6 +875,9 @@ static ssize_t iio_write_channel_info(struct device *dev,
case IIO_VAL_INT:
fract_mult = 0;
break;
+ case IIO_VAL_INT_PLUS_MICRO_DB:
+ scale_db = true;
+ /* fall through */
case IIO_VAL_INT_PLUS_MICRO:
fract_mult = 100000;
break;
@@ -877,6 +902,10 @@ static ssize_t iio_write_channel_info(struct device *dev,
if (ret)
return ret;
}
+ ret = __iio_str_to_fixpoint(buf, fract_mult, &integer, &fract,
+ scale_db);
+ if (ret)
+ return ret;

ret = indio_dev->info->write_raw(indio_dev, this_attr->c,
integer, fract, this_attr->address);
--
2.17.1