[PATCH 1/3] iio: core: add IIO_VAL_INT_MICRO

[Matti Vaittinen]

There are a few cases like light sensor integration times, where values
returned from *_available() and read_raw() are smaller than 1 and often
in the units of micro. (Like micro second scale integration times,
always smaller than 1 second). Currently those are often handled using
IIO_VAL_INT_PLUS_MICRO, which requires drivers to initialize the integer
part to zero. Furthermore, using IIO_VAL_INT_PLUS_MICRO in iio lists
requires one to always allocate the 'dummy' integer part too.

Introduce IIO_VAL_INT_MICRO which allows omitting the always zero integer.

Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
---
 drivers/iio/industrialio-core.c | 4 ++++
 include/linux/iio/types.h       | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index c117f50d0cf3..c5ae965e9961 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -628,6 +628,8 @@ static ssize_t __iio_format_value(char *buf, size_t offset, unsigned int type,
 	switch (type) {
 	case IIO_VAL_INT:
 		return sysfs_emit_at(buf, offset, "%d", vals[0]);
+	case IIO_VAL_INT_MICRO:
+		return sysfs_emit_at(buf, offset, "0.%06u", vals[0]);
 	case IIO_VAL_INT_PLUS_MICRO_DB:
 		scale_db = true;
 		fallthrough;
@@ -758,6 +760,7 @@ static ssize_t iio_format_list(char *buf, const int *vals, int type, int length,
 
 	switch (type) {
 	case IIO_VAL_INT:
+	case IIO_VAL_INT_MICRO:
 		stride = 1;
 		break;
 	default:
@@ -952,6 +955,7 @@ static ssize_t iio_write_channel_info(struct device *dev,
 		case IIO_VAL_INT_PLUS_MICRO_DB:
 			scale_db = true;
 			fallthrough;
+		case IIO_VAL_INT_MICRO:
 		case IIO_VAL_INT_PLUS_MICRO:
 			fract_mult = 100000;
 			break;
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 82faa98c719a..b4e316172c7f 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -30,6 +30,7 @@ enum iio_event_info {
 #define IIO_VAL_FRACTIONAL 10
 #define IIO_VAL_FRACTIONAL_LOG2 11
 #define IIO_VAL_CHAR 12
+#define IIO_VAL_INT_MICRO 13 /* val is micro <units>. Integer part is 0 */
 
 enum iio_available_type {
 	IIO_AVAIL_LIST,
-- 
2.39.2


-- 
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND

~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]

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