iio: stm32 trigger: Add counter enable modes

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@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
index a55ad44446c5fd3f12d1858de7343dc208cafcd4..230020e06677d73a2b8b24c031962e3fbda19c45 100644 (file)
--- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
+++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32
@@ -65,3 +65,28 @@ 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@st.com
+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@st.com
+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 is enabled on rising edge of the connected
+                       trigger, and remains enabled for the duration of this
+                       selected mode.

diff --git a/drivers/iio/trigger/stm32-timer-trigger.c b/drivers/iio/trigger/stm32-timer-trigger.c
index 7db904cae92672d85e2489037f6cdf1fc47376ff..0f1a2cf334bf29fee830aab71c4768c81623e7a5 100644 (file)
--- a/drivers/iio/trigger/stm32-timer-trigger.c
+++ b/drivers/iio/trigger/stm32-timer-trigger.c
@@ -353,6 +353,74 @@ static const struct iio_info stm32_trigger_info = {
        .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 const struct iio_chan_spec_ext_info stm32_trigger_count_info[] = {
        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),
        {}
 };