On 14 October 2015 at 03:55, Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx> wrote:
> 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).
>
Looks good to me. Feel free to pick the patches and amend them
as above.
Thanks a lot!
--
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar
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