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Input: rotary_encoder - support binary encoding of states

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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>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Uwe Kleine-König
2016-07-27 14:36:26 -07:00
committed by Dmitry Torokhov
parent f712a5a052
commit d205a21859
2 changed files with 26 additions and 1 deletions
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23
drivers/input/misc/rotary_encoder.c
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@@ -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");