[PATCH 3/7] iio: adc: stm32: add trigger polarity extended attribute

Fabrice Gasnier
2017-01-19T13:35:46Z

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.gasnier@st.com>
---
drivers/iio/adc/stm32-adc.c | 51 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
index 30708bc..9753c39 100644
--- a/drivers/iio/adc/stm32-adc.c
+++ b/drivers/iio/adc/stm32-adc.c
@@ -164,6 +164,7 @@ struct stm32_adc_trig_info {
* @lock: spinlock
* @bufi: data buffer index
* @num_conv: expected number of scan conversions
+ * @exten: external trigger config (enable/polarity)
*/
struct stm32_adc {
struct stm32_adc_common *common;
@@ -175,6 +176,7 @@ struct stm32_adc {
spinlock_t lock; /* interrupt lock */
int bufi;
int num_conv;
+ enum stm32_adc_exten exten;
};

/**
@@ -449,7 +451,9 @@ static int stm32_adc_set_trig(struct iio_dev *indio_dev,

/* set trigger source, default to rising edge */
extsel = ret;
- exten = STM32_EXTEN_HWTRIG_RISING_EDGE;
+ if (adc->exten == STM32_EXTEN_SWTRIG)
+ adc->exten = STM32_EXTEN_HWTRIG_RISING_EDGE;
+ exten = adc->exten;
}

spin_lock_irqsave(&adc->lock, flags);
@@ -463,6 +467,39 @@ 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->exten = 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->exten;
+}
+
+static const char * const stm32_trig_pol_items[] = {
+ [STM32_EXTEN_SWTRIG] = "swtrig",
+ [STM32_EXTEN_HWTRIG_RISING_EDGE] = "rising-edge",
+ [STM32_EXTEN_HWTRIG_FALLING_EDGE] = "falling-edge",
+ [STM32_EXTEN_HWTRIG_BOTH_EDGES] = "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
@@ -745,6 +782,17 @@ 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_pol", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
+ {
+ .name = "trigger_pol_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,
@@ -760,6 +808,7 @@ 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)
--
1.9.1