Merge branch 'next' into for-linus

1 files changed, 83 insertions, 36 deletions

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 7e64d01da2b..2c8b84dd9da 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -2,6 +2,7 @@
  * rotary_encoder.c
  *
  * (c) 2009 Daniel Mack <daniel@caiaq.de>
+ * Copyright (C) 2011 Johan Hovold <jhovold@gmail.com>
  *
  * state machine code inspired by code from Tim Ruetz
  *
@@ -38,52 +39,66 @@ struct rotary_encoder {
 
 	bool armed;
 	unsigned char dir;	/* 0 - clockwise, 1 - CCW */
+
+	char last_stable;
 };
 
-static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
+static int rotary_encoder_get_state(struct rotary_encoder_platform_data *pdata)
 {
-	struct rotary_encoder *encoder = dev_id;
-	struct rotary_encoder_platform_data *pdata = encoder->pdata;
 	int a = !!gpio_get_value(pdata->gpio_a);
 	int b = !!gpio_get_value(pdata->gpio_b);
-	int state;
 
 	a ^= pdata->inverted_a;
 	b ^= pdata->inverted_b;
-	state = (a << 1) | b;
 
-	switch (state) {
+	return ((a << 1) | b);
+}
 
-	case 0x0:
-		if (!encoder->armed)
-			break;
+static void rotary_encoder_report_event(struct rotary_encoder *encoder)
+{
+	struct rotary_encoder_platform_data *pdata = encoder->pdata;
 
-		if (pdata->relative_axis) {
-			input_report_rel(encoder->input, pdata->axis,
-					 encoder->dir ? -1 : 1);
-		} else {
-			unsigned int pos = encoder->pos;
-
-			if (encoder->dir) {
-				/* turning counter-clockwise */
-				if (pdata->rollover)
-					pos += pdata->steps;
-				if (pos)
-					pos--;
-			} else {
-				/* turning clockwise */
-				if (pdata->rollover || pos < pdata->steps)
-					pos++;
-			}
+	if (pdata->relative_axis) {
+		input_report_rel(encoder->input,
+				 pdata->axis, encoder->dir ? -1 : 1);
+	} else {
+		unsigned int pos = encoder->pos;
+
+		if (encoder->dir) {
+			/* turning counter-clockwise */
 			if (pdata->rollover)
-				pos %= pdata->steps;
-			encoder->pos = pos;
-			input_report_abs(encoder->input, pdata->axis,
-					 encoder->pos);
+				pos += pdata->steps;
+			if (pos)
+				pos--;
+		} else {
+			/* turning clockwise */
+			if (pdata->rollover || pos < pdata->steps)
+				pos++;
 		}
-		input_sync(encoder->input);
 
-		encoder->armed = false;
+		if (pdata->rollover)
+			pos %= pdata->steps;
+
+		encoder->pos = pos;
+		input_report_abs(encoder->input, pdata->axis, encoder->pos);
+	}
+
+	input_sync(encoder->input);
+}
+
+static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
+{
+	struct rotary_encoder *encoder = dev_id;
+	int state;
+
+	state = rotary_encoder_get_state(encoder->pdata);
+
+	switch (state) {
+	case 0x0:
+		if (encoder->armed) {
+			rotary_encoder_report_event(encoder);
+			encoder->armed = false;
+		}
 		break;
 
 	case 0x1:
@@ -100,11 +115,37 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
+{
+	struct rotary_encoder *encoder = dev_id;
+	int state;
+
+	state = rotary_encoder_get_state(encoder->pdata);
+
+	switch (state) {
+	case 0x00:
+	case 0x03:
+		if (state != encoder->last_stable) {
+			rotary_encoder_report_event(encoder);
+			encoder->last_stable = state;
+		}
+		break;
+
+	case 0x01:
+	case 0x02:
+		encoder->dir = (encoder->last_stable + state) & 0x01;
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static int __devinit rotary_encoder_probe(struct platform_device *pdev)
 {
 	struct rotary_encoder_platform_data *pdata = pdev->dev.platform_data;
 	struct rotary_encoder *encoder;
 	struct input_dev *input;
+	irq_handler_t handler;
 	int err;
 
 	if (!pdata) {
@@ -175,7 +216,14 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
 	}
 
 	/* request the IRQs */
-	err = request_irq(encoder->irq_a, &rotary_encoder_irq,
+	if (pdata->half_period) {
+		handler = &rotary_encoder_half_period_irq;
+		encoder->last_stable = rotary_encoder_get_state(pdata);
+	} else {
+		handler = &rotary_encoder_irq;
+	}
+
+	err = request_irq(encoder->irq_a, handler,
 			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 			  DRV_NAME, encoder);
 	if (err) {
@@ -184,7 +232,7 @@ static int __devinit rotary_encoder_probe(struct platform_device *pdev)
 		goto exit_free_gpio_b;
 	}
 
-	err = request_irq(encoder->irq_b, &rotary_encoder_irq,
+	err = request_irq(encoder->irq_b, handler,
 			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
 			  DRV_NAME, encoder);
 	if (err) {
@@ -252,6 +300,5 @@ module_exit(rotary_encoder_exit);
 
 MODULE_ALIAS("platform:" DRV_NAME);
 MODULE_DESCRIPTION("GPIO rotary encoder driver");
-MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>");
+MODULE_AUTHOR("Daniel Mack <daniel@caiaq.de>, Johan Hovold");
 MODULE_LICENSE("GPL v2");
-