On Fri, Oct 09, 2015 at 10:46:56AM -0300, Ezequiel Garcia wrote:
> As per the recent devicetree binding changes, this commit adds the
> support for the new 'steps-per-period' property.
>
> Legacy properties to specify the rotary behavior, are now deprecated
> and instead the new 'steps-per-period' is supported. The default behavior
> is retained.
>
> This allows to support rotary-encoder devices with detents wich are capable
> of producing a stable event on each step.
>
> Signed-off-by: Guido Martínez <guido@xxxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/input/misc/rotary_encoder.c | 87 +++++++++++++++++++++++++++++++++++--
> include/linux/rotary_encoder.h | 2 +-
> 2 files changed, 84 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
> index 15a4cc670a3f..e021615dd3c0 100644
> --- a/drivers/input/misc/rotary_encoder.c
> +++ b/drivers/input/misc/rotary_encoder.c
> @@ -142,6 +142,55 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
> return IRQ_HANDLED;
> }
>
> +static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
> +{
> + struct rotary_encoder *encoder = dev_id;
> + unsigned char sum;
> + int state;
> +
> + state = rotary_encoder_get_state(encoder->pdata);
> +
> + /*
> + * We encode the previous and the current state using a byte.
> + * The previous state in the MSB nibble, the current state in the LSB
> + * nibble. Then use a table to decide the direction of the turn.
> + */
> + sum = (encoder->last_stable << 4) + state;
> + switch (sum) {
> + case 0x31:
> + case 0x10:
> + case 0x02:
> + case 0x23:
> + encoder->dir = 0; /* clockwise */
> + break;
> +
> + case 0x13:
> + case 0x01:
> + case 0x20:
> + case 0x32:
> + encoder->dir = 1; /* counter-clockwise */
> + break;
> +
> + default:
> + /*
> + * Ignore all other values. This covers the case when the
> + * state didn't change (a spurious interrupt) and the
> + * cases where the state changed by two steps, making it
> + * impossible to tell the direction.
> + *
> + * In either case, don't report any event and save the
> + * state for later.
> + */
> + goto out;
> + }
> +
> + rotary_encoder_report_event(encoder);
> +
> +out:
> + encoder->last_stable = state;
> + return IRQ_HANDLED;
> +}
> +
> #ifdef CONFIG_OF
> static const struct of_device_id rotary_encoder_of_match[] = {
> { .compatible = "rotary-encoder", },
> @@ -176,7 +225,26 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
>
> pdata->relative_axis = of_property_read_bool(np, "rotary-encoder,relative-axis");
> pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover");
> - pdata->half_period = of_property_read_bool(np, "rotary-encoder,half-period");
> +
> + if (!of_get_property(np, "rotary-encoder,steps-per-period", NULL)) {
> + /*
> + * Fallback to a one step per period behavior if the
> + * 'steps-per-period' is not set.
> + */
> + pdata->steps_per_period = 1;
> + } else {
> + of_property_read_u32(np, "rotary-encoder,steps-per-period",
> + &pdata->steps_per_period);
> + }
> +
> + /*
> + * The 'half-period' property has been deprecated, you must use
> + * 'steps-per-period' and set an appropriate value.
> + */
> + if (of_get_property(np, "rotary-encoder,half-period", NULL)) {
> + pr_warn(FW_WARN "\"rotary-encoder,half-period\" is deprecated\n");
> + pdata->steps_per_period = 2;
> + }
Hmm, I do not think we need to warn about old DTSes if we consider them
ABI. How about if we parse like this:
error = of_property_read_u32(np, "rotary-encoder,steps-per-period",
&pdata->steps_per_period);
if (error) {
/*
* The 'half-period' property has been deprecated, you must use
* 'steps-per-period' and set an appropriate value, but we still
* need to parse it to maintain compatibility.
*/
if (of_property_read_bool(np, "rotary-encoder,half-period")) {
pdata->steps_per_period = 2;
} else {
/* Fallback to a one step per period behavior */
pdata->steps_per_period = 1;
}
}
(no need to resubmit if you are OK with this).
Thanks.
--
Dmitry
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