On Mon, Mar 27, 2017 at 11:43:24AM +0200, Benjamin Gaignard wrote:
>Device counting could be controlled by the level or the edges of
>a trigger.
>in_count0_enable_mode attibute allow to set the control mode.
>
>Signed-off-by: Benjamin Gaignard <benjamin.gaignard@xxxxxx>
This patch is pretty straight-forward and all right with me. A minor
nitpick inline regarding documentation.
Reviewed-by: William Breathitt Gray <vilhelm.gray@xxxxxxxxx>
>---
> .../ABI/testing/sysfs-bus-iio-timer-stm32 | 23 +++++++
> drivers/iio/trigger/stm32-timer-trigger.c | 70 ++++++++++++++++++++++
> 2 files changed, 93 insertions(+)
>
>diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>index bf795ad..c0a1edc 100644
>--- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>+++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
>@@ -59,3 +59,26 @@ Description:
> quadrature:
> Encoder A and B inputs are mixed to get direction
> and count with a scale of 0.25.
>+
>+What: /sys/bus/iio/devices/iio:deviceX/in_count_enable_mode_available
>+KernelVersion: 4.12
>+Contact: benjamin.gaignard@xxxxxx
>+Description:
>+ Reading returns the list possible enable modes.
>+
>+What: /sys/bus/iio/devices/iio:deviceX/in_count0_enable_mode
>+KernelVersion: 4.12
>+Contact: benjamin.gaignard@xxxxxx
>+Description:
>+ Configure the device counter enable modes, in all case
>+ counting direction is set by in_count0_count_direction
>+ attribute and the counter is clocked by the internal clock.
>+ always:
>+ Counter is always ON.
>+
>+ gated:
>+ Counting is enabled when connected trigger signal
>+ level is high else counting is disabled.
>+
>+ triggered:
>+ Counting start on rising edge of the connected trigger.
When I read the description of the "triggered" mode, I get the
impression that counting is restarted every time there is a rising edge
from the connected trigger signal. However, from our previous
discussions I believe this mode is simply a latched enable.
Perhaps it may be beneficial for clarity to rework the description to
say something along the lines of: "Counting is enabled on rising edge of
the connected trigger, and remains enabled for the duration of this
selected mode."
William Breathitt Gray
>diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
>index 7db904c..0f1a2cf 100644
>--- a/drivers/iio/trigger/stm32-timer-trigger.c
>+++ b/drivers/iio/trigger/stm32-timer-trigger.c
>@@ -353,6 +353,74 @@ static int stm32_counter_write_raw(struct iio_dev *indio_dev,
> .write_raw = stm32_counter_write_raw
> };
>
>+static const char *const stm32_enable_modes[] = {
>+ "always",
>+ "gated",
>+ "triggered",
>+};
>+
>+static int stm32_enable_mode2sms(int mode)
>+{
>+ switch (mode) {
>+ case 0:
>+ return 0;
>+ case 1:
>+ return 5;
>+ case 2:
>+ return 6;
>+ }
>+
>+ return -EINVAL;
>+}
>+
>+static int stm32_set_enable_mode(struct iio_dev *indio_dev,
>+ const struct iio_chan_spec *chan,
>+ unsigned int mode)
>+{
>+ struct stm32_timer_trigger *priv = iio_priv(indio_dev);
>+ int sms = stm32_enable_mode2sms(mode);
>+
>+ if (sms < 0)
>+ return sms;
>+
>+ regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, sms);
>+
>+ return 0;
>+}
>+
>+static int stm32_sms2enable_mode(int mode)
>+{
>+ switch (mode) {
>+ case 0:
>+ return 0;
>+ case 5:
>+ return 1;
>+ case 6:
>+ return 2;
>+ }
>+
>+ return -EINVAL;
>+}
>+
>+static int stm32_get_enable_mode(struct iio_dev *indio_dev,
>+ const struct iio_chan_spec *chan)
>+{
>+ struct stm32_timer_trigger *priv = iio_priv(indio_dev);
>+ u32 smcr;
>+
>+ regmap_read(priv->regmap, TIM_SMCR, &smcr);
>+ smcr &= TIM_SMCR_SMS;
>+
>+ return stm32_sms2enable_mode(smcr);
>+}
>+
>+static const struct iio_enum stm32_enable_mode_enum = {
>+ .items = stm32_enable_modes,
>+ .num_items = ARRAY_SIZE(stm32_enable_modes),
>+ .set = stm32_set_enable_mode,
>+ .get = stm32_get_enable_mode
>+};
>+
> static const char *const stm32_quadrature_modes[] = {
> "channel_A",
> "channel_B",
>@@ -466,6 +534,8 @@ static ssize_t stm32_count_set_preset(struct iio_dev *indio_dev,
> IIO_ENUM_AVAILABLE("count_direction", &stm32_count_direction_enum),
> IIO_ENUM("quadrature_mode", IIO_SEPARATE, &stm32_quadrature_mode_enum),
> IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_quadrature_mode_enum),
>+ IIO_ENUM("enable_mode", IIO_SEPARATE, &stm32_enable_mode_enum),
>+ IIO_ENUM_AVAILABLE("enable_mode", &stm32_enable_mode_enum),
> {}
> };
>
>--
>1.9.1
>
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