Re: [PATCH 2/4] staging:iio:trigger:bfintmr: Only enable timer when necessary

[Jonathan Cameron <jic23@kernel.org>]

On 09/17/2012 01:26 PM, Lars-Peter Clausen wrote:
> This patch hooks up the set_trigger_state callback for the blackfin timer
> trigger driver and only enables the timer when a trigger consumer requests it to
> be enabled. There really is no reason to keep the timer running and generate
> interrupts if nobody is listening to them.
I'll take your word for this one ;)

merged to togreg branch of iio.git
> 
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
> ---
>  drivers/staging/iio/trigger/iio-trig-bfin-timer.c |   27 ++++++++++++++++++---
>  1 file changed, 24 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/staging/iio/trigger/iio-trig-bfin-timer.c b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
> index 2772ea2..d9d3dc9 100644
> --- a/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
> +++ b/drivers/staging/iio/trigger/iio-trig-bfin-timer.c
> @@ -57,12 +57,28 @@ struct bfin_tmr_state {
>  	int irq;
>  };
>  
> +static int iio_bfin_tmr_set_state(struct iio_trigger *trig, bool state)
> +{
> +	struct bfin_tmr_state *st = trig->private_data;
> +
> +	if (get_gptimer_period(st->t->id) == 0)
> +		return -EINVAL;
> +
> +	if (state)
> +		enable_gptimers(st->t->bit);
> +	else
> +		disable_gptimers(st->t->bit);
> +
> +	return 0;
> +}
> +
>  static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
>  		struct device_attribute *attr, const char *buf, size_t count)
>  {
>  	struct iio_trigger *trig = to_iio_trigger(dev);
>  	struct bfin_tmr_state *st = trig->private_data;
>  	long val;
> +	bool enabled;
>  	int ret;
>  
>  	ret = strict_strtoul(buf, 10, &val);
> @@ -74,7 +90,10 @@ static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
>  		goto error_ret;
>  	}
>  
> -	disable_gptimers(st->t->bit);
> +	enabled = get_enabled_gptimers() & st->t->bit;
> +
> +	if (enabled)
> +		disable_gptimers(st->t->bit);
>  
>  	if (!val)
>  		goto error_ret;
> @@ -87,7 +106,9 @@ static ssize_t iio_bfin_tmr_frequency_store(struct device *dev,
>  
>  	set_gptimer_period(st->t->id, val);
>  	set_gptimer_pwidth(st->t->id, 1);
> -	enable_gptimers(st->t->bit);
> +
> +	if (enabled)
> +		enable_gptimers(st->t->bit);
>  
>  error_ret:
>  	return ret ? ret : count;
> @@ -127,7 +148,6 @@ static const struct attribute_group *iio_bfin_tmr_trigger_attr_groups[] = {
>  	NULL
>  };
>  
> -
>  static irqreturn_t iio_bfin_tmr_trigger_isr(int irq, void *devid)
>  {
>  	struct bfin_tmr_state *st = devid;
> @@ -151,6 +171,7 @@ static int iio_bfin_tmr_get_number(int irq)
>  
>  static const struct iio_trigger_ops iio_bfin_tmr_trigger_ops = {
>  	.owner = THIS_MODULE,
> +	.set_trigger_state = iio_bfin_tmr_set_state,
>  };
>  
>  static int __devinit iio_bfin_tmr_trigger_probe(struct platform_device *pdev)
>