path: root/main/linux-rpi/rotary-encoder-fix.patch

commit 47ec6e5a5f57f96d7d382e2d9f8dc5a5bdb45259
Author: Sylvain Rochet <sylvain.rochet@finsecur.com>
Date:   Tue Oct 13 23:24:36 2015 -0700

    Input: rotary_encoder - add wake up support
    
    This patch adds wake up support to GPIO rotary encoders.
    
    Signed-off-by: Sylvain Rochet <sylvain.rochet@finsecur.com>
    Reviewed-by: Johan Hovold <johan@kernel.org>
    Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt
index 3315495..891ddba 100644
--- a/Documentation/devicetree/bindings/input/rotary-encoder.txt
+++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt
@@ -15,6 +15,7 @@ Optional properties:
 - rotary-encoder,rollover: Automatic rollove when the rotary value becomes
   greater than the specified steps or smaller than 0. For absolute axis only.
 - rotary-encoder,half-period: Makes the driver work on half-period mode.
+- wakeup-source: Boolean, rotary encoder can wake up the system.
 
 See Documentation/input/rotary-encoder.txt for more information.
 
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt
index 5737e35..bddbee1 100644
--- a/Documentation/input/rotary-encoder.txt
+++ b/Documentation/input/rotary-encoder.txt
@@ -109,6 +109,7 @@ static struct rotary_encoder_platform_data my_rotary_encoder_info = {
 	.inverted_a	= 0,
 	.inverted_b	= 0,
 	.half_period	= false,
+	.wakeup_source	= false,
 };
 
 static struct platform_device rotary_encoder_device = {
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index f27f81e..d166554 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -26,6 +26,7 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/of_gpio.h>
+#include <linux/pm.h>
 
 #define DRV_NAME "rotary-encoder"
 
@@ -180,6 +181,8 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 					"rotary-encoder,rollover", NULL);
 	pdata->half_period = !!of_get_property(np,
 					"rotary-encoder,half-period", NULL);
+	pdata->wakeup_source = !!of_get_property(np,
+					"wakeup-source", NULL);
 
 	return pdata;
 }
@@ -280,6 +283,8 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 		goto exit_free_irq_b;
 	}
 
+	device_init_wakeup(&pdev->dev, pdata->wakeup_source);
+
 	platform_set_drvdata(pdev, encoder);
 
 	return 0;
@@ -306,6 +311,8 @@ static int rotary_encoder_remove(struct platform_device *pdev)
 	struct rotary_encoder *encoder = platform_get_drvdata(pdev);
 	const struct rotary_encoder_platform_data *pdata = encoder->pdata;
 
+	device_init_wakeup(&pdev->dev, false);
+
 	free_irq(encoder->irq_a, encoder);
 	free_irq(encoder->irq_b, encoder);
 	gpio_free(pdata->gpio_a);
@@ -320,11 +327,41 @@ static int rotary_encoder_remove(struct platform_device *pdev)
 	return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int rotary_encoder_suspend(struct device *dev)
+{
+	struct rotary_encoder *encoder = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		enable_irq_wake(encoder->irq_a);
+		enable_irq_wake(encoder->irq_b);
+	}
+
+	return 0;
+}
+
+static int rotary_encoder_resume(struct device *dev)
+{
+	struct rotary_encoder *encoder = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev)) {
+		disable_irq_wake(encoder->irq_a);
+		disable_irq_wake(encoder->irq_b);
+	}
+
+	return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(rotary_encoder_pm_ops,
+		 rotary_encoder_suspend, rotary_encoder_resume);
+
 static struct platform_driver rotary_encoder_driver = {
 	.probe		= rotary_encoder_probe,
 	.remove		= rotary_encoder_remove,
 	.driver		= {
 		.name	= DRV_NAME,
+		.pm	= &rotary_encoder_pm_ops,
 		.of_match_table = of_match_ptr(rotary_encoder_of_match),
 	}
 };
diff --git a/include/linux/rotary_encoder.h b/include/linux/rotary_encoder.h
index 3f594dc..b33f2d2 100644
--- a/include/linux/rotary_encoder.h
+++ b/include/linux/rotary_encoder.h
@@ -11,6 +11,7 @@ struct rotary_encoder_platform_data {
 	bool relative_axis;
 	bool rollover;
 	bool half_period;
+	bool wakeup_source;
 };
 
 #endif /* __ROTARY_ENCODER_H__ */

commit 648b15cb79e90d80f7b53d0184bdb14132a03754
Author: Ben Gamari <bgamari.foss@gmail.com>
Date:   Tue Oct 13 23:37:28 2015 -0700

    Input: rotary-encoder - use of_property_read_bool
    
    This commit makes uses of_property_read_bool() to read
    boolean properties. This is just cosmetic cleanup.
    
    Signed-off-by: Ben Gamari <bgamari.foss@gmail.com>
    Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index d166554..962f9e8 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -175,14 +175,12 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	pdata->gpio_b = of_get_gpio_flags(np, 1, &flags);
 	pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW;
 
-	pdata->relative_axis = !!of_get_property(np,
-					"rotary-encoder,relative-axis", NULL);
-	pdata->rollover = !!of_get_property(np,
-					"rotary-encoder,rollover", NULL);
-	pdata->half_period = !!of_get_property(np,
-					"rotary-encoder,half-period", NULL);
-	pdata->wakeup_source = !!of_get_property(np,
-					"wakeup-source", NULL);
+	pdata->relative_axis =
+		of_property_read_bool(np, "rotary-encoder,relative-axis");
+	pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover");
+	pdata->half_period =
+		of_property_read_bool(np, "rotary-encoder,half-period");
+	pdata->wakeup_source = of_property_read_bool(np, "wakeup-source");
 
 	return pdata;
 }

commit 3a341a4c30d427fd05617087db1564a595f65093
Author: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Date:   Tue Oct 13 23:39:50 2015 -0700

    Input: rotary-encoder - add support for quarter-period mode
    
    Some encoders have both outputs low in stable states, others also have
    a stable state with both outputs high (half-period mode) and some have
    a stable state in all steps (quarter-period mode). The driver used to
    support the former states and with this change it can also support the
    later.
    
    This commit also deprecates the 'half-period' property and introduces
    a new property 'steps-per-period'. This property specifies the
    number of steps (stable states) produced by the rotary encoder
    for each GPIO period.
    
    Signed-off-by: Guido Martínez <guido@vanguardiasur.com.ar>
    Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
    Acked-by: Rob Herring <robh@kernel.org>
    Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/Documentation/devicetree/bindings/input/rotary-encoder.txt b/Documentation/devicetree/bindings/input/rotary-encoder.txt
index 891ddba..de99cbb 100644
--- a/Documentation/devicetree/bindings/input/rotary-encoder.txt
+++ b/Documentation/devicetree/bindings/input/rotary-encoder.txt
@@ -14,9 +14,18 @@ Optional properties:
   device, hence no steps need to be passed.
 - rotary-encoder,rollover: Automatic rollove when the rotary value becomes
   greater than the specified steps or smaller than 0. For absolute axis only.
-- rotary-encoder,half-period: Makes the driver work on half-period mode.
+- rotary-encoder,steps-per-period: Number of steps (stable states) per period.
+  The values have the following meaning:
+  1: Full-period mode (default)
+  2: Half-period mode
+  4: Quarter-period mode
 - wakeup-source: Boolean, rotary encoder can wake up the system.
 
+Deprecated properties:
+- rotary-encoder,half-period: Makes the driver work on half-period mode.
+  This property is deprecated. Instead, a 'steps-per-period ' value should
+  be used, such as "rotary-encoder,steps-per-period = <2>".
+
 See Documentation/input/rotary-encoder.txt for more information.
 
 Example:
diff --git a/Documentation/input/rotary-encoder.txt b/Documentation/input/rotary-encoder.txt
index bddbee1..46a74f0 100644
--- a/Documentation/input/rotary-encoder.txt
+++ b/Documentation/input/rotary-encoder.txt
@@ -9,8 +9,9 @@ peripherals with two wires. The outputs are phase-shifted by 90 degrees
 and by triggering on falling and rising edges, the turn direction can
 be determined.
 
-Some encoders have both outputs low in stable states, whereas others also have
-a stable state with both outputs high (half-period mode).
+Some encoders have both outputs low in stable states, others also have
+a stable state with both outputs high (half-period mode) and some have
+a stable state in all steps (quarter-period mode).
 
 The phase diagram of these two outputs look like this:
 
@@ -32,6 +33,9 @@ The phase diagram of these two outputs look like this:
                 |<-->|
 	          one step (half-period mode)
 
+                |<>|
+	          one step (quarter-period mode)
+
 For more information, please see
 	https://en.wikipedia.org/wiki/Rotary_encoder
 
diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 962f9e8..8aee719 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -143,6 +143,55 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
+{
+	struct rotary_encoder *encoder = dev_id;
+	unsigned char sum;
+	int state;
+
+	state = rotary_encoder_get_state(encoder->pdata);
+
+	/*
+	 * We encode the previous and the current state using a byte.
+	 * The previous state in the MSB nibble, the current state in the LSB
+	 * nibble. Then use a table to decide the direction of the turn.
+	 */
+	sum = (encoder->last_stable << 4) + state;
+	switch (sum) {
+	case 0x31:
+	case 0x10:
+	case 0x02:
+	case 0x23:
+		encoder->dir = 0; /* clockwise */
+		break;
+
+	case 0x13:
+	case 0x01:
+	case 0x20:
+	case 0x32:
+		encoder->dir = 1; /* counter-clockwise */
+		break;
+
+	default:
+		/*
+		 * Ignore all other values. This covers the case when the
+		 * state didn't change (a spurious interrupt) and the
+		 * cases where the state changed by two steps, making it
+		 * impossible to tell the direction.
+		 *
+		 * In either case, don't report any event and save the
+		 * state for later.
+		 */
+		goto out;
+	}
+
+	rotary_encoder_report_event(encoder);
+
+out:
+	encoder->last_stable = state;
+	return IRQ_HANDLED;
+}
+
 #ifdef CONFIG_OF
 static const struct of_device_id rotary_encoder_of_match[] = {
 	{ .compatible = "rotary-encoder", },
@@ -157,6 +206,7 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	struct device_node *np = dev->of_node;
 	struct rotary_encoder_platform_data *pdata;
 	enum of_gpio_flags flags;
+	int error;
 
 	if (!of_id || !np)
 		return NULL;
@@ -178,8 +228,23 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	pdata->relative_axis =
 		of_property_read_bool(np, "rotary-encoder,relative-axis");
 	pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover");
-	pdata->half_period =
-		of_property_read_bool(np, "rotary-encoder,half-period");
+
+	error = of_property_read_u32(np, "rotary-encoder,steps-per-period",
+				     &pdata->steps_per_period);
+	if (error) {
+		/*
+		 * The 'half-period' property has been deprecated, you must use
+		 * 'steps-per-period' and set an appropriate value, but we still
+		 * need to parse it to maintain compatibility.
+		 */
+		if (of_property_read_bool(np, "rotary-encoder,half-period")) {
+			pdata->steps_per_period = 2;
+		} else {
+			/* Fallback to one step per period behavior */
+			pdata->steps_per_period = 1;
+		}
+	}
+
 	pdata->wakeup_source = of_property_read_bool(np, "wakeup-source");
 
 	return pdata;
@@ -251,12 +316,23 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 	encoder->irq_a = gpio_to_irq(pdata->gpio_a);
 	encoder->irq_b = gpio_to_irq(pdata->gpio_b);
 
-	/* request the IRQs */
-	if (pdata->half_period) {
+	switch (pdata->steps_per_period) {
+	case 4:
+		handler = &rotary_encoder_quarter_period_irq;
+		encoder->last_stable = rotary_encoder_get_state(pdata);
+		break;
+	case 2:
 		handler = &rotary_encoder_half_period_irq;
 		encoder->last_stable = rotary_encoder_get_state(pdata);
-	} else {
+		break;
+	case 1:
 		handler = &rotary_encoder_irq;
+		break;
+	default:
+		dev_err(dev, "'%d' is not a valid steps-per-period value\n",
+			pdata->steps_per_period);
+		err = -EINVAL;
+		goto exit_free_gpio_b;
 	}
 
 	err = request_irq(encoder->irq_a, handler,
diff --git a/include/linux/rotary_encoder.h b/include/linux/rotary_encoder.h
index b33f2d2..fe3dc64 100644
--- a/include/linux/rotary_encoder.h
+++ b/include/linux/rotary_encoder.h
@@ -8,9 +8,9 @@ struct rotary_encoder_platform_data {
 	unsigned int gpio_b;
 	unsigned int inverted_a;
 	unsigned int inverted_b;
+	unsigned int steps_per_period;
 	bool relative_axis;
 	bool rollover;
-	bool half_period;
 	bool wakeup_source;
 };
 

commit 0f940be407b87ca629fa2f3085f613483a075b16
Author: Timo Teräs <timo.teras@iki.fi>
Date:   Fri Jan 15 15:24:14 2016 +0200

    Input: rotary_encoder - convert to devm-* api
    
    Use managed resource API for simplifying error paths.
    
    Signed-off-by: Timo Teräs <timo.teras@iki.fi>

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 8aee719..0f23d32 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -211,8 +211,8 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	if (!of_id || !np)
 		return NULL;
 
-	pdata = kzalloc(sizeof(struct rotary_encoder_platform_data),
-			GFP_KERNEL);
+	pdata = devm_kzalloc(dev, sizeof(struct rotary_encoder_platform_data),
+			     GFP_KERNEL);
 	if (!pdata)
 		return ERR_PTR(-ENOMEM);
 
@@ -277,12 +277,10 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 		}
 	}
 
-	encoder = kzalloc(sizeof(struct rotary_encoder), GFP_KERNEL);
-	input = input_allocate_device();
-	if (!encoder || !input) {
-		err = -ENOMEM;
-		goto exit_free_mem;
-	}
+	encoder = devm_kzalloc(dev, sizeof(struct rotary_encoder), GFP_KERNEL);
+	input = devm_input_allocate_device(dev);
+	if (!encoder || !input)
+		return -ENOMEM;
 
 	encoder->input = input;
 	encoder->pdata = pdata;
@@ -301,16 +299,16 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 	}
 
 	/* request the GPIOs */
-	err = gpio_request_one(pdata->gpio_a, GPIOF_IN, dev_name(dev));
+	err = devm_gpio_request_one(dev, pdata->gpio_a, GPIOF_IN, dev_name(dev));
 	if (err) {
 		dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_a);
-		goto exit_free_mem;
+		return err;
 	}
 
-	err = gpio_request_one(pdata->gpio_b, GPIOF_IN, dev_name(dev));
+	err = devm_gpio_request_one(dev, pdata->gpio_b, GPIOF_IN, dev_name(dev));
 	if (err) {
 		dev_err(dev, "unable to request GPIO %d\n", pdata->gpio_b);
-		goto exit_free_gpio_a;
+		return err;
 	}
 
 	encoder->irq_a = gpio_to_irq(pdata->gpio_a);
@@ -331,30 +329,29 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 	default:
 		dev_err(dev, "'%d' is not a valid steps-per-period value\n",
 			pdata->steps_per_period);
-		err = -EINVAL;
-		goto exit_free_gpio_b;
+		return-EINVAL;
 	}
 
-	err = request_irq(encoder->irq_a, handler,
-			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
-			  DRV_NAME, encoder);
+	err = devm_request_irq(dev, encoder->irq_a, handler,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+			       DRV_NAME, encoder);
 	if (err) {
 		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a);
-		goto exit_free_gpio_b;
+		return err;
 	}
 
-	err = request_irq(encoder->irq_b, handler,
-			  IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
-			  DRV_NAME, encoder);
+	err = devm_request_irq(dev, encoder->irq_b, handler,
+			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+			       DRV_NAME, encoder);
 	if (err) {
 		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b);
-		goto exit_free_irq_a;
+		return err;
 	}
 
 	err = input_register_device(input);
 	if (err) {
 		dev_err(dev, "failed to register input device\n");
-		goto exit_free_irq_b;
+		return err;
 	}
 
 	device_init_wakeup(&pdev->dev, pdata->wakeup_source);
@@ -362,42 +359,12 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, encoder);
 
 	return 0;
-
-exit_free_irq_b:
-	free_irq(encoder->irq_b, encoder);
-exit_free_irq_a:
-	free_irq(encoder->irq_a, encoder);
-exit_free_gpio_b:
-	gpio_free(pdata->gpio_b);
-exit_free_gpio_a:
-	gpio_free(pdata->gpio_a);
-exit_free_mem:
-	input_free_device(input);
-	kfree(encoder);
-	if (!dev_get_platdata(&pdev->dev))
-		kfree(pdata);
-
-	return err;
 }
 
 static int rotary_encoder_remove(struct platform_device *pdev)
 {
-	struct rotary_encoder *encoder = platform_get_drvdata(pdev);
-	const struct rotary_encoder_platform_data *pdata = encoder->pdata;
-
 	device_init_wakeup(&pdev->dev, false);
 
-	free_irq(encoder->irq_a, encoder);
-	free_irq(encoder->irq_b, encoder);
-	gpio_free(pdata->gpio_a);
-	gpio_free(pdata->gpio_b);
-
-	input_unregister_device(encoder->input);
-	kfree(encoder);
-
-	if (!dev_get_platdata(&pdev->dev))
-		kfree(pdata);
-
 	return 0;
 }
 

commit 3467a8dafd27e2c6c1545028ea4e4a78701031df
Author: Timo Teräs <timo.teras@iki.fi>
Date:   Fri Jan 15 15:37:00 2016 +0200

    Input: rotary_encoder - fix device tree error handling
    
    of_get_gpio_flags() can fail, so pass through the error code
    properly. Most important use case is when it returns EPROBE_DEFER
    so that the probe gets called again later.
    
    Signed-off-by: Timo Teräs <timo.teras@iki.fi>

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 0f23d32..156f40f 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -206,7 +206,7 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	struct device_node *np = dev->of_node;
 	struct rotary_encoder_platform_data *pdata;
 	enum of_gpio_flags flags;
-	int error;
+	int ret;
 
 	if (!of_id || !np)
 		return NULL;
@@ -219,19 +219,25 @@ static struct rotary_encoder_platform_data *rotary_encoder_parse_dt(struct devic
 	of_property_read_u32(np, "rotary-encoder,steps", &pdata->steps);
 	of_property_read_u32(np, "linux,axis", &pdata->axis);
 
-	pdata->gpio_a = of_get_gpio_flags(np, 0, &flags);
+	ret = of_get_gpio_flags(np, 0, &flags);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	pdata->gpio_a = ret;
 	pdata->inverted_a = flags & OF_GPIO_ACTIVE_LOW;
 
-	pdata->gpio_b = of_get_gpio_flags(np, 1, &flags);
+	ret = of_get_gpio_flags(np, 1, &flags);
+	if (ret < 0)
+		return ERR_PTR(ret);
+	pdata->gpio_b = ret;
 	pdata->inverted_b = flags & OF_GPIO_ACTIVE_LOW;
 
 	pdata->relative_axis =
 		of_property_read_bool(np, "rotary-encoder,relative-axis");
 	pdata->rollover = of_property_read_bool(np, "rotary-encoder,rollover");
 
-	error = of_property_read_u32(np, "rotary-encoder,steps-per-period",
-				     &pdata->steps_per_period);
-	if (error) {
+	ret = of_property_read_u32(np, "rotary-encoder,steps-per-period",
+				   &pdata->steps_per_period);
+	if (ret) {
 		/*
 		 * The 'half-period' property has been deprecated, you must use
 		 * 'steps-per-period' and set an appropriate value, but we still

commit 85bec2ad5ac7ee79b3f1d264947a5b4dc4c5ef6e (HEAD -> master)
Author: Timo Teräs <timo.teras@iki.fi>
Date:   Fri Jan 15 15:55:48 2016 +0200

    Input: rotary_encoder - use threaded irqs
    
    Convert to use threaded IRQs to support GPIOs that can sleep.
    Protect the irq handler with mutex as it can be triggered from
    two different irq lines accessing the same state.
    
    This allows using GPIO expanders behind I2C or SPI bus.
    
    Signed-off-by: Timo Teräs <timo.teras@iki.fi>

diff --git a/drivers/input/misc/rotary_encoder.c b/drivers/input/misc/rotary_encoder.c
index 156f40f..a2d47ce 100644
--- a/drivers/input/misc/rotary_encoder.c
+++ b/drivers/input/misc/rotary_encoder.c
@@ -33,6 +33,7 @@
 struct rotary_encoder {
 	struct input_dev *input;
 	const struct rotary_encoder_platform_data *pdata;
+	struct mutex access_mutex;
 
 	unsigned int axis;
 	unsigned int pos;
@@ -48,8 +49,8 @@ struct rotary_encoder {
 
 static int rotary_encoder_get_state(const struct rotary_encoder_platform_data *pdata)
 {
-	int a = !!gpio_get_value(pdata->gpio_a);
-	int b = !!gpio_get_value(pdata->gpio_b);
+	int a = !!gpio_get_value_cansleep(pdata->gpio_a);
+	int b = !!gpio_get_value_cansleep(pdata->gpio_b);
 
 	a ^= pdata->inverted_a;
 	b ^= pdata->inverted_b;
@@ -94,6 +95,7 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
 	struct rotary_encoder *encoder = dev_id;
 	int state;
 
+	mutex_lock(&encoder->access_mutex);
 	state = rotary_encoder_get_state(encoder->pdata);
 
 	switch (state) {
@@ -114,6 +116,7 @@ static irqreturn_t rotary_encoder_irq(int irq, void *dev_id)
 		encoder->armed = true;
 		break;
 	}
+	mutex_unlock(&encoder->access_mutex);
 
 	return IRQ_HANDLED;
 }
@@ -123,6 +126,7 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
 	struct rotary_encoder *encoder = dev_id;
 	int state;
 
+	mutex_lock(&encoder->access_mutex);
 	state = rotary_encoder_get_state(encoder->pdata);
 
 	switch (state) {
@@ -139,6 +143,7 @@ static irqreturn_t rotary_encoder_half_period_irq(int irq, void *dev_id)
 		encoder->dir = (encoder->last_stable + state) & 0x01;
 		break;
 	}
+	mutex_unlock(&encoder->access_mutex);
 
 	return IRQ_HANDLED;
 }
@@ -149,6 +154,7 @@ static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
 	unsigned char sum;
 	int state;
 
+	mutex_lock(&encoder->access_mutex);
 	state = rotary_encoder_get_state(encoder->pdata);
 
 	/*
@@ -189,6 +195,8 @@ static irqreturn_t rotary_encoder_quarter_period_irq(int irq, void *dev_id)
 
 out:
 	encoder->last_stable = state;
+	mutex_unlock(&encoder->access_mutex);
+
 	return IRQ_HANDLED;
 }
 
@@ -288,6 +296,8 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 	if (!encoder || !input)
 		return -ENOMEM;
 
+	mutex_init(&encoder->access_mutex);
+
 	encoder->input = input;
 	encoder->pdata = pdata;
 
@@ -338,17 +348,17 @@ static int rotary_encoder_probe(struct platform_device *pdev)
 		return-EINVAL;
 	}
 
-	err = devm_request_irq(dev, encoder->irq_a, handler,
-			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
-			       DRV_NAME, encoder);
+	err = devm_request_threaded_irq(dev, encoder->irq_a, NULL, handler,
+					IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+					DRV_NAME, encoder);
 	if (err) {
 		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_a);
 		return err;
 	}
 
-	err = devm_request_irq(dev, encoder->irq_b, handler,
-			       IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
-			       DRV_NAME, encoder);
+	err = devm_request_threaded_irq(dev, encoder->irq_b, NULL, handler,
+					IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING,
+					DRV_NAME, encoder);
 	if (err) {
 		dev_err(dev, "unable to request IRQ %d\n", encoder->irq_b);
 		return err;