From d205a2185938e38c8667405dc44cd6221c71682e Mon Sep 17 00:00:00 2001 From: =?utf8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 27 Jul 2016 14:36:26 -0700 Subject: [PATCH] Input: rotary_encoder - support binary encoding of states MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit It's not advisable to use this encoding, but to support existing devices add support for this to the driver. Signed-off-by: Uwe Kleine-König Acked-by: Rob Herring Signed-off-by: Dmitry Torokhov --- .../bindings/input/rotary-encoder.txt | 4 ++++ drivers/input/misc/rotary_encoder.c | 23 ++++++++++++++++++- 2 files changed, 26 insertions(+), 1 deletion(-) diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt index 6c9f0c8a846c..e85ce3dea480 100644 --- a/Documentation/devicetree/bindings/input/rotary-encoder.txt +++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt @@ -20,6 +20,8 @@ Optional properties: 2: Half-period mode 4: Quarter-period mode - wakeup-source: Boolean, rotary encoder can wake up the system. +- rotary-encoder,encoding: String, the method used to encode steps. + Supported are "gray" (the default and more common) and "binary". Deprecated properties: - rotary-encoder,half-period: Makes the driver work on half-period mode. @@ -34,6 +36,7 @@ Example: compatible = "rotary-encoder"; gpios = <&gpio 19 1>, <&gpio 20 0>; /* GPIO19 is inverted */ linux,axis = <0>; /* REL_X */ + rotary-encoder,encoding = "gray"; rotary-encoder,relative-axis; }; @@ -42,5 +45,6 @@ Example: gpios = <&gpio 21 0>, <&gpio 22 0>; linux,axis = <1>; /* ABS_Y */ rotary-encoder,steps = <24>; + rotary-encoder,encoding = "binary"; rotary-encoder,rollover; }; diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c index c7fc8d4fb080..1588aecafff7 100644 --- a/drivers/input/misc/rotary_encoder.c +++ b/drivers/input/misc/rotary_encoder.c @@ -28,6 +28,11 @@ #define DRV_NAME "rotary-encoder" +enum rotary_encoder_encoding { + ROTENC_GRAY, + ROTENC_BINARY, +}; + struct rotary_encoder { struct input_dev *input; @@ -37,6 +42,7 @@ struct rotary_encoder { u32 axis; bool relative_axis; bool rollover; + enum rotary_encoder_encoding encoding; unsigned int pos; @@ -57,8 +63,9 @@ static unsigned int rotary_encoder_get_state(struct rotary_encoder *encoder) for (i = 0; i < encoder->gpios->ndescs; ++i) { int val = gpiod_get_value_cansleep(encoder->gpios->desc[i]); + /* convert from gray encoding to normal */ - if (ret & 1) + if (encoder->encoding == ROTENC_GRAY && ret & 1) val = !val; ret = ret << 1 | val; @@ -213,6 +220,20 @@ static int rotary_encoder_probe(struct platform_device *pdev) encoder->rollover = device_property_read_bool(dev, "rotary-encoder,rollover"); + if (!device_property_present(dev, "rotary-encoder,encoding") || + !device_property_match_string(dev, "rotary-encoder,encoding", + "gray")) { + dev_info(dev, "gray"); + encoder->encoding = ROTENC_GRAY; + } else if (!device_property_match_string(dev, "rotary-encoder,encoding", + "binary")) { + dev_info(dev, "binary"); + encoder->encoding = ROTENC_BINARY; + } else { + dev_err(dev, "unknown encoding setting\n"); + return -EINVAL; + } + device_property_read_u32(dev, "linux,axis", &encoder->axis); encoder->relative_axis = device_property_read_bool(dev, "rotary-encoder,relative-axis"); -- 2.20.1