Re: [PATCH 2/2] iio: make stm32 trigger driver use INDIO_HARDWARE_TRIGGERED mode

[Jonathan Cameron <jic23@kernel.org>]

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 <benjamin.gaignard@st.com>
> 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
> 
> 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:	benjamin.gaignard@st.com
>> +Description:
>> +		Reading returns the list possible trigger modes.
>> +
>> +What:		/sys/bus/iio/devices/iio:deviceX/in_count0_trigger_mode
>> +KernelVersion:	4.13
>> +Contact:	benjamin.gaignard@st.com
>> +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;
>>
> 
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