On Sun, May 07, 2017 at 02:49:16PM +0100, Jonathan Cameron wrote: >On 01/05/17 01:50, Jonathan Cameron wrote: >> On 27/04/17 14:29, Benjamin Gaignard wrote: >>> Add validate function to be use to use the correct trigger. >>> Add an attribute to configure device mode like for quadrature and >>> enable modes >>> >>> Signed-off-by: Benjamin Gaignard <[email protected]> >> Hmm. I think I quite like this as an approach but have changed my >> mind several times over the last few days :) >> >> Hence I'd ideally like some more opinions and will be leaving it >> on the list for at least a short time longer. >> >> It's missed the current merge window anyway so plenty of time to >> tick off this last element of your support. >> >> I also just checked and our docs for the existing modes is rubbish >> (or I can't find it with a quick grep ;) >> so we should tidy that up and add some description of this as well. >Still looking for more input on this! > >Lars - do you have time for a quick look? > >No real rush though as we are early in the cycle. > >Thanks, > >Jonathan
I haven't used triggers before in my drivers so perhaps I can provide the naive perspective of someone approaching the API for the first time. >From what I gather, the INDIO_BUFFERED_TRIGGERED option is used for triggers associated with a buffer; for example, a device keeping track of ambient temperature may periodically sample its sensors and store the data in a buffer for later evaluation. The INDIO_EVENT_TRIGGERED option appears to be used for triggers associated with some sort of event; for example, a threshold voltage is reached on an ADC device. I'm having trouble groking how the INDIO_HARDWARE_TRIGGERED option differs from the INDIO_EVENT_TRIGGERED option. It looks like the INDIO_HARDWARE_TRIGGERED option is used in this case to associate a trigger with a clock edge (first timer chained to second timer). Wouldn't an INDIO_EVENT_TRIGGERED option be sufficient in this case where the event is defined as the clock edge input to the second timer? William Breathitt Gray >> >> Jonathan >>> --- >>> .../ABI/testing/sysfs-bus-iio-timer-stm32 | 15 ++++++ >>> drivers/iio/trigger/stm32-timer-trigger.c | 61 >>> ++++++++++++++++++++++ >>> 2 files changed, 76 insertions(+) >>> >>> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 >>> b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 >>> index 230020e..cccdf57 100644 >>> --- a/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 >>> +++ b/Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 >>> @@ -90,3 +90,18 @@ Description: >>> Counting is enabled on rising edge of the connected >>> trigger, and remains enabled for the duration of this >>> selected mode. >>> + >>> +What: >>> /sys/bus/iio/devices/iio:deviceX/in_count_trigger_mode_available >>> +KernelVersion: 4.13 >>> +Contact: [email protected] >>> +Description: >>> + Reading returns the list possible trigger modes. >>> + >>> +What: /sys/bus/iio/devices/iio:deviceX/in_count0_trigger_mode >>> +KernelVersion: 4.13 >>> +Contact: [email protected] >>> +Description: >>> + Configure the device counter trigger mode >>> + counting direction is set by in_count0_count_direction >>> + attribute and the counter is clocked by the connected trigger >>> + rising edges. >>> diff --git a/drivers/iio/trigger/stm32-timer-trigger.c >>> b/drivers/iio/trigger/stm32-timer-trigger.c >>> index 0f1a2cf..7c6e90e 100644 >>> --- a/drivers/iio/trigger/stm32-timer-trigger.c >>> +++ b/drivers/iio/trigger/stm32-timer-trigger.c >>> @@ -347,12 +347,70 @@ static int stm32_counter_write_raw(struct iio_dev >>> *indio_dev, >>> return -EINVAL; >>> } >>> >>> +static int stm32_counter_validate_trigger(struct iio_dev *indio_dev, >>> + struct iio_trigger *trig) >>> +{ >>> + struct stm32_timer_trigger *priv = iio_priv(indio_dev); >>> + const char * const *cur = priv->valids; >>> + unsigned int i = 0; >>> + >>> + if (!is_stm32_timer_trigger(trig)) >>> + return -EINVAL; >>> + >>> + while (cur && *cur) { >>> + if (!strncmp(trig->name, *cur, strlen(trig->name))) { >>> + regmap_update_bits(priv->regmap, >>> + TIM_SMCR, TIM_SMCR_TS, >>> + i << TIM_SMCR_TS_SHIFT); >>> + return 0; >>> + } >>> + cur++; >>> + i++; >>> + } >>> + >>> + return -EINVAL; >>> +} >>> + >>> static const struct iio_info stm32_trigger_info = { >>> .driver_module = THIS_MODULE, >>> + .validate_trigger = stm32_counter_validate_trigger, >>> .read_raw = stm32_counter_read_raw, >>> .write_raw = stm32_counter_write_raw >>> }; >>> >>> +static const char *const stm32_trigger_modes[] = { >>> + "trigger", >>> +}; >>> + >>> +static int stm32_set_trigger_mode(struct iio_dev *indio_dev, >>> + const struct iio_chan_spec *chan, >>> + unsigned int mode) >>> +{ >>> + struct stm32_timer_trigger *priv = iio_priv(indio_dev); >>> + >>> + regmap_update_bits(priv->regmap, TIM_SMCR, TIM_SMCR_SMS, TIM_SMCR_SMS); >>> + >>> + return 0; >>> +} >>> + >>> +static int stm32_get_trigger_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); >>> + >>> + return smcr == TIM_SMCR_SMS ? 0 : -EINVAL; >>> +} >>> + >>> +static const struct iio_enum stm32_trigger_mode_enum = { >>> + .items = stm32_trigger_modes, >>> + .num_items = ARRAY_SIZE(stm32_trigger_modes), >>> + .set = stm32_set_trigger_mode, >>> + .get = stm32_get_trigger_mode >>> +}; >>> + >>> static const char *const stm32_enable_modes[] = { >>> "always", >>> "gated", >>> @@ -536,6 +594,8 @@ static ssize_t stm32_count_set_preset(struct iio_dev >>> *indio_dev, >>> 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), >>> + IIO_ENUM("trigger_mode", IIO_SEPARATE, &stm32_trigger_mode_enum), >>> + IIO_ENUM_AVAILABLE("trigger_mode", &stm32_trigger_mode_enum), >>> {} >>> }; >>> >>> @@ -560,6 +620,7 @@ static struct stm32_timer_trigger >>> *stm32_setup_counter_device(struct device *dev >>> indio_dev->name = dev_name(dev); >>> indio_dev->dev.parent = dev; >>> indio_dev->info = &stm32_trigger_info; >>> + indio_dev->modes = INDIO_HARDWARE_TRIGGERED; >>> indio_dev->num_channels = 1; >>> indio_dev->channels = &stm32_trigger_channel; >>> indio_dev->dev.of_node = dev->of_node; >>> >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-iio" in >> the body of a message to [email protected] >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> >
