Re: [PATCH 1/1] Input: rotary-encoder: Add 'stepped' irq handler

[Daniel Mack <zonque@gmail.com>]

Hi Ezequiel,

On 28.09.2013 20:26, Ezequiel Garcia wrote:
> Some rotary-encoder devices (such as those with detents) are capable
> of producing a stable event on each step. This commit adds support
> for this case, by implementing a new interruption handler.
> 
> The handler needs only detect the direction of the turn and generate
> an event according to this detection.
> 

> +static irqreturn_t rotary_encoder_stepped_irq(int irq, void *dev_id)
> +{
> +	struct rotary_encoder *encoder = dev_id;
> +	int state, sum;
> +
> +	state = rotary_encoder_get_state(encoder->pdata);
> +
> +	/*
> +	 * We encode the previous and the current state,
> +	 * in the 'sum' variable and then use a table
> +	 * to decide the direction of the turn.
> +	 */
> +	sum = (encoder->last_stable << 2) + state;
> +	switch (sum) {
> +	case 0b1101:
> +	case 0b0100:
> +	case 0b0010:
> +	case 0b1011:

Binary constants are frowned upon, please avoid them in the kernel.
checkpatch.pl should have warned you about them as well.

> diff --git a/include/linux/rotary_encoder.h b/include/linux/rotary_encoder.h
> index 3f594dc..499f6f7 100644
> --- a/include/linux/rotary_encoder.h
> +++ b/include/linux/rotary_encoder.h
> @@ -11,6 +11,7 @@ struct rotary_encoder_platform_data {
>  	bool relative_axis;
>  	bool rollover;
>  	bool half_period;
> +	bool on_each_step;

Care to add a DT binding for this property as well?


Other than that, this looks good to me, but I can't test it due to the
lack of hardware.


Thanks,
Daniel