Input: rotary_encoder - support binary encoding of states

[cascardo/linux.git] / drivers / input / misc / rotary_encoder.c

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 96c486d..1588aec 100644 (file)
--- 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;
 
@@ -47,18 +53,19 @@ struct rotary_encoder {
        bool armed;
        signed char dir;        /* 1 - clockwise, -1 - CCW */
 
-       unsigned last_stable;
+       unsigned int last_stable;
 };
 
-static unsigned rotary_encoder_get_state(struct rotary_encoder *encoder)
+static unsigned int rotary_encoder_get_state(struct rotary_encoder *encoder)
 {
        int i;
-       unsigned ret = 0;
+       unsigned int ret = 0;
 
        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;
@@ -100,7 +107,7 @@ static void rotary_encoder_report_event(struct rotary_encoder *encoder)
 static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
 {
        struct rotary_encoder *encoder = dev_id;
-       unsigned state;
+       unsigned int state;
 
        mutex_lock(&encoder->access_mutex);
 
@@ -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");