| Message ID | 1460055528-13814-1-git-send-email-u.kleine-koenig@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 7, 2016 at 1:58 PM, Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote: > 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 <u.kleine-koenig@pengutronix.de> > --- Ack for the binding, but... > @@ -213,6 +222,17 @@ static int rotary_encoder_probe(struct platform_device *pdev) > encoder->rollover = > device_property_read_bool(dev, "rotary-encoder,rollover"); > > + err = device_property_read_string(dev, "rotary-encoder,encoding", > + &encoding); > + if (!err && !strcmp(encoding, "binary")) { > + encoder->encoding = ROTENC_BINARY; > + } else if (err || !strcmp(encoding, "gray")) { > + encoder->encoding = ROTENC_GRAY; > + } else { > + dev_err(dev, "unknown encoding setting"); > + return -EINVAL; device_property_match_string() here instead. > + } > + > device_property_read_u32(dev, "linux,axis", &encoder->axis); > encoder->relative_axis = > device_property_read_bool(dev, "rotary-encoder,relative-axis"); -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello Rob, On Thu, Apr 07, 2016 at 05:45:00PM -0500, Rob Herring wrote: > On Thu, Apr 7, 2016 at 1:58 PM, Uwe Kleine-König > <u.kleine-koenig@pengutronix.de> wrote: > > 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 <u.kleine-koenig@pengutronix.de> > > --- > > Ack for the binding, but... Thanks. Actually I already had your ack for v2 and only dropped it to make you look over the patch again :-) > > @@ -213,6 +222,17 @@ static int rotary_encoder_probe(struct platform_device *pdev) > > encoder->rollover = > > device_property_read_bool(dev, "rotary-encoder,rollover"); > > > > + err = device_property_read_string(dev, "rotary-encoder,encoding", > > + &encoding); > > + if (!err && !strcmp(encoding, "binary")) { > > + encoder->encoding = ROTENC_BINARY; > > + } else if (err || !strcmp(encoding, "gray")) { > > + encoder->encoding = ROTENC_GRAY; > > + } else { > > + dev_err(dev, "unknown encoding setting"); > > + return -EINVAL; > > device_property_match_string() here instead. With the added downside that the property is parsed at least twice from dt, right? This is not a hot path, but still I wonder if it simplyfies the driver code enough to be worth the effort? Also this seems to have a different semantic and allows the property to be an array. Best regards Uwe
On Fri, Apr 08, 2016 at 08:40:58AM +0200, Uwe Kleine-König wrote: > Hello Rob, > > On Thu, Apr 07, 2016 at 05:45:00PM -0500, Rob Herring wrote: > > On Thu, Apr 7, 2016 at 1:58 PM, Uwe Kleine-König > > <u.kleine-koenig@pengutronix.de> wrote: > > > 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 <u.kleine-koenig@pengutronix.de> > > > --- > > > > Ack for the binding, but... > > Thanks. Actually I already had your ack for v2 and only dropped it to > make you look over the patch again :-) > > > > @@ -213,6 +222,17 @@ static int rotary_encoder_probe(struct platform_device *pdev) > > > encoder->rollover = > > > device_property_read_bool(dev, "rotary-encoder,rollover"); > > > > > > + err = device_property_read_string(dev, "rotary-encoder,encoding", > > > + &encoding); > > > + if (!err && !strcmp(encoding, "binary")) { > > > + encoder->encoding = ROTENC_BINARY; > > > + } else if (err || !strcmp(encoding, "gray")) { > > > + encoder->encoding = ROTENC_GRAY; > > > + } else { > > > + dev_err(dev, "unknown encoding setting"); > > > + return -EINVAL; > > > > device_property_match_string() here instead. > > With the added downside that the property is parsed at least twice from > dt, right? This is not a hot path, but still I wonder if it simplyfies > the driver code enough to be worth the effort? IMO, yes. > Also this seems to have a different semantic and allows the property to > be an array. It is not really the kernel's job to validate crap in bindings. If you put '"binary", "gray"' in your DT, then the kernel may or may not handle that. Rob -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 96c486de49e0..1e17e28188c6 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; @@ -57,9 +63,11 @@ static unsigned 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) - val = !val; + + if (encoder->encoding == ROTENC_GRAY) + /* convert from gray encoding to binary */ + if (ret & 1) + val = !val; ret = ret << 1 | val; } @@ -183,6 +191,7 @@ static int rotary_encoder_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct rotary_encoder *encoder; struct input_dev *input; + const char *encoding; irq_handler_t handler; u32 steps_per_period; unsigned int i; @@ -213,6 +222,17 @@ static int rotary_encoder_probe(struct platform_device *pdev) encoder->rollover = device_property_read_bool(dev, "rotary-encoder,rollover"); + err = device_property_read_string(dev, "rotary-encoder,encoding", + &encoding); + if (!err && !strcmp(encoding, "binary")) { + encoder->encoding = ROTENC_BINARY; + } else if (err || !strcmp(encoding, "gray")) { + encoder->encoding = ROTENC_GRAY; + } else { + dev_err(dev, "unknown encoding setting"); + return -EINVAL; + } + device_property_read_u32(dev, "linux,axis", &encoder->axis); encoder->relative_axis = device_property_read_bool(dev, "rotary-encoder,relative-axis");
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 <u.kleine-koenig@pengutronix.de> --- Notes: Changes since (implicit) v1, sent with Message-Id: 1458680914-4533-1-git-send-email-u.kleine-koenig@pengutronix.de - switch format of dt properties to use strings Changes since v2, sent with Message-Id: 1458806232-22403-1-git-send-email-u.kleine-koenig@pengutronix.de - be more strict about parsing the encoding string .../devicetree/bindings/input/rotary-encoder.txt | 4 ++++ drivers/input/misc/rotary_encoder.c | 26 +++++++++++++++++++--- 2 files changed, 27 insertions(+), 3 deletions(-)