[PATCH 1/2] iio: Add support for waveform output

[PATCH 1/2] iio: Add support for waveform output

[George McCollister]

Output can be held high or low for a specified period of time.
Support for waveform capture could be added in the future.

Signed-off-by: George McCollister <george.mccollister@gmail.com>
---
 Documentation/ABI/testing/sysfs-bus-iio               | 7 +++++++
 drivers/iio/industrialio-core.c                       | 3 +++
 drivers/staging/iio/Documentation/iio_event_monitor.c | 2 ++
 include/linux/iio/types.h                             | 5 ++++-
 4 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio
index d760b02..47df169 100644
--- a/Documentation/ABI/testing/sysfs-bus-iio
+++ b/Documentation/ABI/testing/sysfs-bus-iio
@@ -1028,3 +1028,10 @@ Contact:	linux-iio@vger.kernel.org
 Description:
 		Raw value of rotation from true/magnetic north measured with
 		or without compensation from tilt sensors.
+
+What:		/sys/bus/iio/devices/iio:deviceX/out_waveformY_hightime_raw
+What:		/sys/bus/iio/devices/iio:deviceX/out_waveformY_lowtime_raw
+KernelVersion:	3.18
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Raw value of time for output to be held high or low.
diff --git a/drivers/iio/industrialio-core.c b/drivers/iio/industrialio-core.c
index af3e76d..343e784 100644
--- a/drivers/iio/industrialio-core.c
+++ b/drivers/iio/industrialio-core.c
@@ -70,6 +70,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_CCT] = "cct",
 	[IIO_PRESSURE] = "pressure",
 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
+	[IIO_WAVEFORM] = "waveform",
 };
 
 static const char * const iio_modifier_names[] = {
@@ -91,6 +92,8 @@ static const char * const iio_modifier_names[] = {
 	[IIO_MOD_NORTH_TRUE] = "from_north_true",
 	[IIO_MOD_NORTH_MAGN_TILT_COMP] = "from_north_magnetic_tilt_comp",
 	[IIO_MOD_NORTH_TRUE_TILT_COMP] = "from_north_true_tilt_comp",
+	[IIO_MOD_HIGHTIME] = "hightime",
+	[IIO_MOD_LOWTIME] = "lowtime",
 };
 
 /* relies on pairs of these shared then separate */
diff --git a/drivers/staging/iio/Documentation/iio_event_monitor.c b/drivers/staging/iio/Documentation/iio_event_monitor.c
index 569d6f8..690f261 100644
--- a/drivers/staging/iio/Documentation/iio_event_monitor.c
+++ b/drivers/staging/iio/Documentation/iio_event_monitor.c
@@ -49,6 +49,7 @@ static const char * const iio_chan_type_name_spec[] = {
 	[IIO_CCT] = "cct",
 	[IIO_PRESSURE] = "pressure",
 	[IIO_HUMIDITYRELATIVE] = "humidityrelative",
+	[IIO_WAVEFORM] = "waveform",
 };
 
 static const char * const iio_ev_type_text[] = {
@@ -108,6 +109,7 @@ static bool event_is_known(struct iio_event_data *event)
 	case IIO_CCT:
 	case IIO_PRESSURE:
 	case IIO_HUMIDITYRELATIVE:
+	case IIO_WAVEFORM:
 		break;
 	default:
 		return false;
diff --git a/include/linux/iio/types.h b/include/linux/iio/types.h
index 4a2af8a..d3b0af1 100644
--- a/include/linux/iio/types.h
+++ b/include/linux/iio/types.h
@@ -30,6 +30,7 @@ enum iio_chan_type {
 	IIO_CCT,
 	IIO_PRESSURE,
 	IIO_HUMIDITYRELATIVE,
+	IIO_WAVEFORM,
 };
 
 enum iio_modifier {
@@ -59,7 +60,9 @@ enum iio_modifier {
 	IIO_MOD_NORTH_MAGN,
 	IIO_MOD_NORTH_TRUE,
 	IIO_MOD_NORTH_MAGN_TILT_COMP,
-	IIO_MOD_NORTH_TRUE_TILT_COMP
+	IIO_MOD_NORTH_TRUE_TILT_COMP,
+	IIO_MOD_HIGHTIME,
+	IIO_MOD_LOWTIME,
 };
 
 enum iio_event_type {
-- 
2.1.0

Re: [PATCH 1/2] iio: Add support for waveform output

[Lars-Peter Clausen]

On 11/26/2014 10:45 PM, George McCollister wrote:
> Output can be held high or low for a specified period of time.
> Support for waveform capture could be added in the future.
>

That's a PWM device?

Re: [PATCH 1/2] iio: Add support for waveform output

[Lars-Peter Clausen]

On 12/01/2014 03:57 PM, George McCollister wrote:
> On Wed, Nov 26, 2014 at 4:06 PM, Lars-Peter Clausen <lars@metafoo.de> wrote:
>> On 11/26/2014 10:45 PM, George McCollister wrote:
>>>
>>> Output can be held high or low for a specified period of time.
>>> Support for waveform capture could be added in the future.
>>>
>>
>> That's a PWM device?
>
> The device I'm adding only generates a single pulse per write, but my
> intention was to leave the door open for other types of devices.
>

Can you try to elaborate more on how exactly this interface is supposed to 
be used, what kind of the devices it is used for, the use case of the device 
and so on. This patch is adding userspace ABI which we have to maintain 
forever so we should try to give this proper review, which is not easy 
without knowing what it actually is.

- Lars