From 3a341a4c30d427fd05617087db1564a595f65093 Mon Sep 17 00:00:00 2001 From: Ezequiel Garcia Date: Tue, 13 Oct 2015 23:39:50 -0700 Subject: Input: rotary-encoder - add support for quarter-period mode MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some encoders have both outputs low in stable states, others also have a stable state with both outputs high (half-period mode) and some have a stable state in all steps (quarter-period mode). The driver used to support the former states and with this change it can also support the later. This commit also deprecates the 'half-period' property and introduces a new property 'steps-per-period'. This property specifies the number of steps (stable states) produced by the rotary encoder for each GPIO period. Signed-off-by: Guido Martínez Signed-off-by: Ezequiel Garcia Acked-by: Rob Herring Signed-off-by: Dmitry Torokhov --- Documentation/input/rotary-encoder.txt | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'Documentation/input') diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt index bddbee188624..46a74f0c551a 100644 --- a/Documentation/input/rotary-encoder.txt +++ b/Documentation/input/rotary-encoder.txt @@ -9,8 +9,9 @@ peripherals with two wires. The outputs are phase-shifted by 90 degrees and by triggering on falling and rising edges, the turn direction can be determined. -Some encoders have both outputs low in stable states, whereas others also have -a stable state with both outputs high (half-period mode). +Some encoders have both outputs low in stable states, others also have +a stable state with both outputs high (half-period mode) and some have +a stable state in all steps (quarter-period mode). The phase diagram of these two outputs look like this: @@ -32,6 +33,9 @@ The phase diagram of these two outputs look like this: |<-->| one step (half-period mode) + |<>| + one step (quarter-period mode) + For more information, please see https://en.wikipedia.org/wiki/Rotary_encoder -- cgit v1.2.3