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

Message ID 1484832854-6314-4-git-send-email-fabrice.gasnier@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Fabrice Gasnier Jan. 19, 2017, 1:34 p.m. UTC
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(-)

Comments

Jonathan Cameron Jan. 22, 2017, 12:58 p.m. UTC | #1
On 19/01/17 13:34, 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.gasnier@st.com>
Creates a custom attibute.  Documentation please!
/Documentation/ABI/testing/sysfs-bus-iio-stm32 or similar.

The approach seems reasonable, but easier to discuss when it's
formally described.

I'd also not care about characters saved and go with 
trigger_polarity rather than the short form (unless this you have
a good reason for it!)

Jonathan
> ---
>  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)
>
Fabrice Gasnier Jan. 24, 2017, 2:41 p.m. UTC | #2
On 01/22/2017 01:58 PM, Jonathan Cameron wrote:
> On 19/01/17 13:34, 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.gasnier@st.com>
> Creates a custom attibute.  Documentation please!
> /Documentation/ABI/testing/sysfs-bus-iio-stm32 or similar.

Ok, I'll add something like:
Documentation/ABI/testing/sysfs-bus-iio-adc-stm32:

+What:		/sys/bus/iio/devices/triggerX/trigger_polarity
+KernelVersion:	4.11
+Contact:	fabrice.gasnier@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.

Best Regards,
Thanks,
Fabrice
>
> The approach seems reasonable, but easier to discuss when it's
> formally described.
>
> I'd also not care about characters saved and go with
> trigger_polarity rather than the short form (unless this you have
> a good reason for it!)
>
> Jonathan
>> ---
>>  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)
>>
>
diff mbox

Patch

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)