On 26/01/17 14:28, Fabrice Gasnier wrote:
> Define extended attribute so that user may choose rising, falling or both
> edges for external trigger sources.
> Default to rising edge in case it isn't set.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasn...@st.com>
Applied though as discussed we might want some ability to add
a default for external triggers via dt.
Can be added later.
Pushed out as testing for the autobuilders to play with it.
Thanks,
Jonathan
> ---
> Changes in v2:
> - Rename and document new trigger_polarity custom attribute
> ---
> Documentation/ABI/testing/sysfs-bus-iio-adc-stm32 | 18 +++++++++
> drivers/iio/adc/stm32-adc.c | 46
> ++++++++++++++++++++++-
> 2 files changed, 63 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-adc-stm32
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-iio-adc-stm32
> b/Documentation/ABI/testing/sysfs-bus-iio-adc-stm32
> new file mode 100644
> index 0000000..efe4c85
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-bus-iio-adc-stm32
> @@ -0,0 +1,18 @@
> +What: /sys/bus/iio/devices/triggerX/trigger_polarity
> +KernelVersion: 4.11
> +Contact: fabrice.gasn...@st.com
> +Description:
> + The STM32 ADC can be configured to use external trigger sources
> + (e.g. timers, pwm or exti gpio). Then, it can be tuned to start
> + conversions on external trigger by either:
> + - "rising-edge"
> + - "falling-edge"
> + - "both-edges".
> + Reading returns current trigger polarity.
> + Writing value before enabling conversions sets trigger polarity.
> +
> +What: /sys/bus/iio/devices/triggerX/trigger_polarity_available
> +KernelVersion: 4.11
> +Contact: fabrice.gasn...@st.com
> +Description:
> + List all available trigger_polarity settings.
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 87d984b..9a38f9a 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -135,6 +135,7 @@ struct stm32_adc_regs {
> * @lock: spinlock
> * @bufi: data buffer index
> * @num_conv: expected number of scan conversions
> + * @trigger_polarity: external trigger polarity (e.g. exten)
> */
> struct stm32_adc {
> struct stm32_adc_common *common;
> @@ -146,6 +147,7 @@ struct stm32_adc {
> spinlock_t lock; /* interrupt lock */
> unsigned int bufi;
> unsigned int num_conv;
> + u32 trigger_polarity;
> };
>
> /**
> @@ -410,7 +412,7 @@ static int stm32_adc_set_trig(struct iio_dev *indio_dev,
>
> /* set trigger source and polarity (default to rising edge) */
> extsel = ret;
> - exten = STM32_EXTEN_HWTRIG_RISING_EDGE;
> + exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE;
> }
>
> spin_lock_irqsave(&adc->lock, flags);
> @@ -424,6 +426,36 @@ static int stm32_adc_set_trig(struct iio_dev *indio_dev,
> return 0;
> }
>
> +static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan,
> + unsigned int type)
> +{
> + struct stm32_adc *adc = iio_priv(indio_dev);
> +
> + adc->trigger_polarity = type;
> +
> + return 0;
> +}
> +
> +static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev,
> + const struct iio_chan_spec *chan)
> +{
> + struct stm32_adc *adc = iio_priv(indio_dev);
> +
> + return adc->trigger_polarity;
> +}
> +
> +static const char * const stm32_trig_pol_items[] = {
> + "rising-edge", "falling-edge", "both-edges",
> +};
> +
> +const struct iio_enum stm32_adc_trig_pol = {
> + .items = stm32_trig_pol_items,
> + .num_items = ARRAY_SIZE(stm32_trig_pol_items),
> + .get = stm32_adc_get_trig_pol,
> + .set = stm32_adc_set_trig_pol,
> +};
> +
> /**
> * stm32_adc_single_conv() - Performs a single conversion
> * @indio_dev: IIO device
> @@ -682,6 +714,17 @@ static irqreturn_t stm32_adc_trigger_handler(int irq,
> void *p)
> return IRQ_HANDLED;
> }
>
> +static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
> + IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
> + {
> + .name = "trigger_polarity_available",
> + .shared = IIO_SHARED_BY_ALL,
> + .read = iio_enum_available_read,
> + .private = (uintptr_t)&stm32_adc_trig_pol,
> + },
> + {},
> +};
> +
> static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
> struct iio_chan_spec *chan,
> const struct stm32_adc_chan_spec *channel,
> @@ -697,6 +740,7 @@ static void stm32_adc_chan_init_one(struct iio_dev
> *indio_dev,
> chan->scan_type.sign = 'u';
> chan->scan_type.realbits = 12;
> chan->scan_type.storagebits = 16;
> + chan->ext_info = stm32_adc_ext_info;
> }
>
> static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
>
