[PATCH v2 0/5] Input: hynitron-cst816x: axes, gesture keys and panel power

[PATCH v2 0/5] Input: hynitron-cst816x: axes, gesture keys and panel power

[Daniel Golle]

This series improves the hynitron-cst816x touchscreen driver. It makes
the driver respect the common touchscreen axis properties, which are
now documented in the binding as well, it keeps gesture keys from
getting stuck, and it lets the controller follow the panel it is
mounted on.

The gesture key is reported with the controller's touch flag as its
value, so the key stays pressed once the controller stops reporting
the gesture code. The controller has no lift event to offer, so the
keys are now released on the first report carrying no gesture code, or
40 ms after the last one that carried a code, whichever comes first.

Boards which mount the controller on the panel feed it from the
panel's rail, so the reset and the interrupt now wait for the panel to
be prepared, which the common 'panel' phandle asks for.

Changes since v1:
- the binding allows touchscreen-min-x/y, touchscreen-size-x/y and
  touchscreen-fuzz-x/y as well, which touchscreen_parse_properties()
  already honours; the 240x240 default is unchanged
- the binding allows the 'panel' phandle, and patch 5 is new: it
  follows the panel's power sequence
- the binding commit message carries a justification (Conor Dooley)
- keycodes above KEY_MAX are rejected, which keeps the gesture key
  lookup inside the input core's key bitmap (Sashiko AI review)
- the timed release is skipped when the interrupt handler re-armed the
  timer while the timer callback waited for the lock (Sashiko AI
  review)
- the Sashiko AI review also asked about additionalProperties next to
  a $ref, which stays, as this binding allows a subset of
  touchscreen.yaml (writing-schema.rst)

Link: https://lore.kernel.org/r/cover.1790851590.git.daniel@makrotopia.org

Daniel Golle (5):
  dt-bindings: input: touchscreen: hynitron,cst816x: axes and panel
  Input: hynitron-cst816x: respect touchscreen DT properties
  Input: hynitron-cst816x: release gesture keys
  Input: hynitron-cst816x: time out gesture key release
  Input: hynitron-cst816x: power sequence with the panel

 .../input/touchscreen/hynitron,cst816x.yaml   |  16 ++
 drivers/input/touchscreen/Kconfig             |   2 +
 drivers/input/touchscreen/hynitron-cst816x.c  | 182 +++++++++++++++---
 3 files changed, 171 insertions(+), 29 deletions(-)


base-commit: 6474fa070f2b8013b4b87350b775b8c3be6e8aac
-- 
2.55.0

[PATCH v2 1/5] dt-bindings: input: touchscreen: hynitron,cst816x: axes and panel

[Daniel Golle]

The chip hands out coordinates in its own frame and knows nothing of
the panel it is glued to, so how it is oriented against that panel,
which coordinate range the assembly reports and how noisy it is are
properties of the board. Reference touchscreen.yaml so that a board
can state them with the common axis properties. Allow the 'panel'
phandle as well, since these controllers are mounted on the panel and
fed from its rail, which asks for the two to be power sequenced
together.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
v2:
- allow touchscreen-min-x/y, touchscreen-size-x/y and
  touchscreen-fuzz-x/y as well (Sashiko AI review)
- allow the 'panel' phandle
- justify the change in the commit message (Conor Dooley)

 .../input/touchscreen/hynitron,cst816x.yaml      | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
index 72d4da636881e..027a2b3dcf2e8 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
@@ -36,6 +36,18 @@ properties:
       - description: Slide right gesture
       - description: Long press gesture
 
+  panel: true
+
+  touchscreen-min-x: true
+  touchscreen-min-y: true
+  touchscreen-size-x: true
+  touchscreen-size-y: true
+  touchscreen-fuzz-x: true
+  touchscreen-fuzz-y: true
+  touchscreen-inverted-x: true
+  touchscreen-inverted-y: true
+  touchscreen-swapped-x-y: true
+
 required:
   - compatible
   - reg
@@ -43,6 +55,9 @@ required:
 
 additionalProperties: false
 
+allOf:
+  - $ref: touchscreen.yaml#
+
 examples:
   - |
     #include <dt-bindings/gpio/gpio.h>
@@ -59,6 +74,7 @@ examples:
             reset-gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
             linux,keycodes = <KEY_UP>, <KEY_DOWN>, <KEY_LEFT>, <KEY_RIGHT>,
                              <BTN_TOOL_TRIPLETAP>;
+            touchscreen-swapped-x-y;
         };
     };
 
-- 
2.55.0

Re: [PATCH v2 1/5] dt-bindings: input: touchscreen: hynitron,cst816x: axes and panel

[Krzysztof Kozlowski]

On Fri, Oct 02, 2026 at 01:47:21PM +0100, Daniel Golle wrote:
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> index 72d4da636881e..027a2b3dcf2e8 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> @@ -36,6 +36,18 @@ properties:
>        - description: Slide right gesture
>        - description: Long press gesture
>  
> +  panel: true
> +
> +  touchscreen-min-x: true
> +  touchscreen-min-y: true
> +  touchscreen-size-x: true
> +  touchscreen-size-y: true
> +  touchscreen-fuzz-x: true
> +  touchscreen-fuzz-y: true
> +  touchscreen-inverted-x: true
> +  touchscreen-inverted-y: true
> +  touchscreen-swapped-x-y: true
> +
>  required:
>    - compatible
>    - reg
> @@ -43,6 +55,9 @@ required:
>  
>  additionalProperties: false

So just use unevaluatedProperties instead of listing almost entire
contents of touchscreen.yaml.

Re: [PATCH v2 1/5] dt-bindings: input: touchscreen: hynitron,cst816x: axes and panel

[Daniel Golle]

On Sun, Oct 04, 2026 at 09:24:26AM +0200, Krzysztof Kozlowski wrote:
> On Fri, Oct 02, 2026 at 01:47:21PM +0100, Daniel Golle wrote:
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> > index 72d4da636881e..027a2b3dcf2e8 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
> > @@ -36,6 +36,18 @@ properties:
> >        - description: Slide right gesture
> >        - description: Long press gesture
> >  
> > +  panel: true
> > +
> > +  touchscreen-min-x: true
> > +  touchscreen-min-y: true
> > +  touchscreen-size-x: true
> > +  touchscreen-size-y: true
> > +  touchscreen-fuzz-x: true
> > +  touchscreen-fuzz-y: true
> > +  touchscreen-inverted-x: true
> > +  touchscreen-inverted-y: true
> > +  touchscreen-swapped-x-y: true
> > +
> >  required:
> >    - compatible
> >    - reg
> > @@ -43,6 +55,9 @@ required:
> >  
> >  additionalProperties: false
> 
> So just use unevaluatedProperties instead of listing almost entire
> contents of touchscreen.yaml.
> 

"almost" is the keyword here. If it is acceptable to include properties
the driver doesn't (and will never) parse, I'll do that instead.

Re: [PATCH v2 1/5] dt-bindings: input: touchscreen: hynitron,cst816x: axes and panel

[Krzysztof Kozlowski]

On 04/10/2026 09:29, Daniel Golle wrote:
> On Sun, Oct 04, 2026 at 09:24:26AM +0200, Krzysztof Kozlowski wrote:
>> On Fri, Oct 02, 2026 at 01:47:21PM +0100, Daniel Golle wrote:
>>> diff --git a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
>>> index 72d4da636881e..027a2b3dcf2e8 100644
>>> --- a/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
>>> +++ b/Documentation/devicetree/bindings/input/touchscreen/hynitron,cst816x.yaml
>>> @@ -36,6 +36,18 @@ properties:
>>>        - description: Slide right gesture
>>>        - description: Long press gesture
>>>  
>>> +  panel: true
>>> +
>>> +  touchscreen-min-x: true
>>> +  touchscreen-min-y: true
>>> +  touchscreen-size-x: true
>>> +  touchscreen-size-y: true
>>> +  touchscreen-fuzz-x: true
>>> +  touchscreen-fuzz-y: true
>>> +  touchscreen-inverted-x: true
>>> +  touchscreen-inverted-y: true
>>> +  touchscreen-swapped-x-y: true
>>> +
>>>  required:
>>>    - compatible
>>>    - reg
>>> @@ -43,6 +55,9 @@ required:
>>>  
>>>  additionalProperties: false
>>
>> So just use unevaluatedProperties instead of listing almost entire
>> contents of touchscreen.yaml.
>>
> 
> "almost" is the keyword here. If it is acceptable to include properties
> the driver doesn't (and will never) parse, I'll do that instead.

And if you add them to the driver, you would be changing the binding? We
ask instead to post complete binding (see also writing-bindings).

Best regards,
Krzysztof

[PATCH v2 2/5] Input: hynitron-cst816x: respect touchscreen DT properties

[Daniel Golle]

Parse common touchscreen properties and use touchscreen_report_pos()
instead of reporting raw absolute position.

This makes the driver respect the touchscreen-min-x/y,
touchscreen-size-x/y, touchscreen-fuzz-x/y, touchscreen-inverted-x/y
and touchscreen-swapped-x-y properties.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
v2:
- name all the properties the parser honours, no functional change

 drivers/input/touchscreen/hynitron-cst816x.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/hynitron-cst816x.c b/drivers/input/touchscreen/hynitron-cst816x.c
index 47d9cd7412d1b..865c5a767ba01 100644
--- a/drivers/input/touchscreen/hynitron-cst816x.c
+++ b/drivers/input/touchscreen/hynitron-cst816x.c
@@ -11,6 +11,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/i2c.h>
 #include <linux/input.h>
+#include <linux/input/touchscreen.h>
 #include <linux/unaligned.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
@@ -31,6 +32,7 @@ struct cst816x_priv {
 	struct input_dev *input;
 	unsigned int keycode[CST816X_NUM_KEYS];
 	unsigned int keycodemax;
+	struct touchscreen_properties prop;
 };
 
 static int cst816x_parse_keycodes(struct device *dev, struct cst816x_priv *priv)
@@ -142,6 +144,7 @@ static int cst816x_register_input(struct cst816x_priv *priv)
 	input_set_abs_params(priv->input, ABS_X, 0, 240, 0, 0);
 	input_set_abs_params(priv->input, ABS_Y, 0, 240, 0, 0);
 	input_set_capability(priv->input, EV_KEY, BTN_TOUCH);
+	touchscreen_parse_properties(priv->input, false, &priv->prop);
 
 	priv->input->keycode = priv->keycode;
 	priv->input->keycodesize = sizeof(priv->keycode[0]);
@@ -173,8 +176,8 @@ static irqreturn_t cst816x_irq_cb(int irq, void *cookie)
 	if (!cst816x_process_touch(priv, &tch))
 		return IRQ_HANDLED;
 
-	input_report_abs(priv->input, ABS_X, tch.abs_x);
-	input_report_abs(priv->input, ABS_Y, tch.abs_y);
+	touchscreen_report_pos(priv->input, &priv->prop,
+			       tch.abs_x, tch.abs_y, false);
 
 	if (tch.gest)
 		input_report_key(priv->input,
-- 
2.55.0

[PATCH v2 3/5] Input: hynitron-cst816x: release gesture keys

[Daniel Golle]

The gesture key is reported with the value of the touch flag, so it
stays pressed once the controller stops reporting the gesture code
while the finger is still down. Report the press on its own and
release the keys the input core still holds down on the first report
that carries no gesture code. Keycodes above KEY_MAX are rejected,
as that release looks the key state up in the input core's key bitmap.

Fixes: c87a819bec86 ("Input: add driver for Hynitron CST816x series")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
v2:
- reject keycodes above KEY_MAX and publish keycodemax only once the
  whole array validates (Sashiko AI review)

 drivers/input/touchscreen/hynitron-cst816x.c | 67 ++++++++++++++------
 1 file changed, 46 insertions(+), 21 deletions(-)

diff --git a/drivers/input/touchscreen/hynitron-cst816x.c b/drivers/input/touchscreen/hynitron-cst816x.c
index 865c5a767ba01..725c8bd4c1d0e 100644
--- a/drivers/input/touchscreen/hynitron-cst816x.c
+++ b/drivers/input/touchscreen/hynitron-cst816x.c
@@ -39,28 +39,40 @@ static int cst816x_parse_keycodes(struct device *dev, struct cst816x_priv *priv)
 {
 	int count;
 	int error;
+	int i;
 
-	if (device_property_present(dev, "linux,keycodes")) {
-		count = device_property_count_u32(dev, "linux,keycodes");
-		if (count < 0) {
-			error = count;
-			dev_err(dev, "failed to count keys: %d\n", error);
-			return error;
-		} else if (count > ARRAY_SIZE(priv->keycode)) {
-			dev_err(dev, "too many keys defined: %d\n", count);
-			return -EINVAL;
-		}
-		priv->keycodemax = count;
-
-		error = device_property_read_u32_array(dev, "linux,keycodes",
-						       priv->keycode,
-						       priv->keycodemax);
-		if (error) {
-			dev_err(dev, "failed to read keycodes: %d\n", error);
-			return error;
-		}
+	if (!device_property_present(dev, "linux,keycodes"))
+		return 0;
+
+	count = device_property_count_u32(dev, "linux,keycodes");
+	if (count < 0) {
+		error = count;
+		dev_err(dev, "failed to count keys: %d\n", error);
+		return error;
+	}
+
+	if (count > ARRAY_SIZE(priv->keycode)) {
+		dev_err(dev, "too many keys defined: %d\n", count);
+		return -EINVAL;
+	}
+
+	error = device_property_read_u32_array(dev, "linux,keycodes",
+					       priv->keycode, count);
+	if (error) {
+		dev_err(dev, "failed to read keycodes: %d\n", error);
+		return error;
 	}
 
+	for (i = 0; i < count; i++) {
+		if (priv->keycode[i] <= KEY_MAX)
+			continue;
+
+		dev_err(dev, "keycode %u out of range\n", priv->keycode[i]);
+		return -EINVAL;
+	}
+
+	priv->keycodemax = count;
+
 	return 0;
 }
 
@@ -168,6 +180,18 @@ static void cst816x_reset(struct cst816x_priv *priv)
 	msleep(100);
 }
 
+static void cst816x_release_keys(struct cst816x_priv *priv)
+{
+	unsigned int i;
+
+	for (i = 0; i < priv->keycodemax; i++) {
+		if (!test_bit(priv->keycode[i], priv->input->key))
+			continue;
+
+		input_report_key(priv->input, priv->keycode[i], 0);
+	}
+}
+
 static irqreturn_t cst816x_irq_cb(int irq, void *cookie)
 {
 	struct cst816x_priv *priv = cookie;
@@ -181,8 +205,9 @@ static irqreturn_t cst816x_irq_cb(int irq, void *cookie)
 
 	if (tch.gest)
 		input_report_key(priv->input,
-				 priv->keycode[cst816x_gest_idx(tch.gest)],
-				 tch.active);
+				 priv->keycode[cst816x_gest_idx(tch.gest)], 1);
+	else
+		cst816x_release_keys(priv);
 
 	input_report_key(priv->input, BTN_TOUCH, tch.active);
 
-- 
2.55.0

[PATCH v2 4/5] Input: hynitron-cst816x: time out gesture key release

[Daniel Golle]

The controller reports a gesture code once and can then stay quiet
until the next touch, which leaves the gesture key pressed for as long
as the panel is left alone. Release the gesture keys 40 ms after the
last report that carried a gesture code, so that the release comes
from whichever happens first, the timeout or a report without a
gesture code. The 40 ms matches TSC200X_PENUP_TIME_MS, chosen there
for the same want of a lift event from the controller, and has to stay
above the interval between consecutive reports of a held gesture.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
v2:
- skip the release when the interrupt handler re-armed the timer while
  the timer callback waited for the lock (Sashiko AI review)

 drivers/input/touchscreen/hynitron-cst816x.c | 52 ++++++++++++++++++--
 1 file changed, 49 insertions(+), 3 deletions(-)

diff --git a/drivers/input/touchscreen/hynitron-cst816x.c b/drivers/input/touchscreen/hynitron-cst816x.c
index 725c8bd4c1d0e..f17c2b03396a1 100644
--- a/drivers/input/touchscreen/hynitron-cst816x.c
+++ b/drivers/input/touchscreen/hynitron-cst816x.c
@@ -15,9 +15,12 @@
 #include <linux/unaligned.h>
 #include <linux/interrupt.h>
 #include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
 
 #define CST816X_RD_REG		0x01
 #define CST816X_NUM_KEYS	5
+#define CST816X_GEST_HOLD_MS	40
 
 struct cst816x_touch {
 	u8 gest;
@@ -32,6 +35,9 @@ struct cst816x_priv {
 	struct input_dev *input;
 	unsigned int keycode[CST816X_NUM_KEYS];
 	unsigned int keycodemax;
+	struct timer_list release_timer;
+	/* lock keeps the timeout out of the middle of a report */
+	spinlock_t lock;
 	struct touchscreen_properties prop;
 };
 
@@ -180,8 +186,9 @@ static void cst816x_reset(struct cst816x_priv *priv)
 	msleep(100);
 }
 
-static void cst816x_release_keys(struct cst816x_priv *priv)
+static bool cst816x_release_keys(struct cst816x_priv *priv)
 {
+	bool released = false;
 	unsigned int i;
 
 	for (i = 0; i < priv->keycodemax; i++) {
@@ -189,33 +196,66 @@ static void cst816x_release_keys(struct cst816x_priv *priv)
 			continue;
 
 		input_report_key(priv->input, priv->keycode[i], 0);
+		released = true;
 	}
+
+	return released;
+}
+
+static void cst816x_release_timeout(struct timer_list *t)
+{
+	struct cst816x_priv *priv = timer_container_of(priv, t, release_timer);
+	unsigned long flags;
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	/* a re-arm while this waited for the lock supersedes the timeout */
+	if (!timer_pending(&priv->release_timer) && cst816x_release_keys(priv))
+		input_sync(priv->input);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
 }
 
 static irqreturn_t cst816x_irq_cb(int irq, void *cookie)
 {
 	struct cst816x_priv *priv = cookie;
 	struct cst816x_touch tch;
+	unsigned long flags;
 
 	if (!cst816x_process_touch(priv, &tch))
 		return IRQ_HANDLED;
 
+	spin_lock_irqsave(&priv->lock, flags);
+
 	touchscreen_report_pos(priv->input, &priv->prop,
 			       tch.abs_x, tch.abs_y, false);
 
-	if (tch.gest)
+	if (tch.gest) {
 		input_report_key(priv->input,
 				 priv->keycode[cst816x_gest_idx(tch.gest)], 1);
-	else
+		mod_timer(&priv->release_timer,
+			  jiffies + msecs_to_jiffies(CST816X_GEST_HOLD_MS));
+	} else {
+		timer_delete(&priv->release_timer);
 		cst816x_release_keys(priv);
+	}
 
 	input_report_key(priv->input, BTN_TOUCH, tch.active);
 
 	input_sync(priv->input);
 
+	spin_unlock_irqrestore(&priv->lock, flags);
+
 	return IRQ_HANDLED;
 }
 
+static void cst816x_timer_stop(void *data)
+{
+	struct cst816x_priv *priv = data;
+
+	timer_delete_sync(&priv->release_timer);
+}
+
 static int cst816x_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -227,6 +267,8 @@ static int cst816x_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	priv->client = client;
+	spin_lock_init(&priv->lock);
+	timer_setup(&priv->release_timer, cst816x_release_timeout, 0);
 
 	priv->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
 	if (IS_ERR(priv->reset))
@@ -244,6 +286,10 @@ static int cst816x_probe(struct i2c_client *client)
 	if (error)
 		return dev_err_probe(dev, error, "input register failed\n");
 
+	error = devm_add_action_or_reset(dev, cst816x_timer_stop, priv);
+	if (error)
+		return error;
+
 	error = devm_request_threaded_irq(dev, client->irq,
 					  NULL, cst816x_irq_cb, IRQF_ONESHOT,
 					  dev_driver_string(dev), priv);
-- 
2.55.0

[PATCH v2 5/5] Input: hynitron-cst816x: power sequence with the panel

[Daniel Golle]

Boards which mount the controller on the panel feed it from the
panel's rail, where a reset and the first interrupts are only
meaningful once the panel is powered. Register as a DRM panel follower
when the device tree points at a panel, so that the reset stays
asserted and the interrupt masked until the panel is prepared, and a
pressed key is released before the panel goes down again.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>
---
v2: new patch

 drivers/input/touchscreen/Kconfig            |  2 +
 drivers/input/touchscreen/hynitron-cst816x.c | 60 ++++++++++++++++++--
 2 files changed, 57 insertions(+), 5 deletions(-)

diff --git a/drivers/input/touchscreen/Kconfig b/drivers/input/touchscreen/Kconfig
index 9b9ae8ac3f7fd..0beb499e24f20 100644
--- a/drivers/input/touchscreen/Kconfig
+++ b/drivers/input/touchscreen/Kconfig
@@ -478,6 +478,8 @@ config TOUCHSCREEN_HYNITRON_CSTXXX
 config TOUCHSCREEN_HYNITRON_CST816X
 	tristate "Hynitron CST816x touchscreen"
 	depends on I2C
+	# We call into panel code, so if DRM=m, this can't be 'y'
+	depends on DRM || !DRM
 	help
 	  Say Y here if you have a touchscreen using a Hynitron
 	  CST816x series touchscreen controller.
diff --git a/drivers/input/touchscreen/hynitron-cst816x.c b/drivers/input/touchscreen/hynitron-cst816x.c
index f17c2b03396a1..2e786f617067f 100644
--- a/drivers/input/touchscreen/hynitron-cst816x.c
+++ b/drivers/input/touchscreen/hynitron-cst816x.c
@@ -18,6 +18,8 @@
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 
+#include <drm/drm_panel.h>
+
 #define CST816X_RD_REG		0x01
 #define CST816X_NUM_KEYS	5
 #define CST816X_GEST_HOLD_MS	40
@@ -39,6 +41,7 @@ struct cst816x_priv {
 	/* lock keeps the timeout out of the middle of a report */
 	spinlock_t lock;
 	struct touchscreen_properties prop;
+	struct drm_panel_follower follower;
 };
 
 static int cst816x_parse_keycodes(struct device *dev, struct cst816x_priv *priv)
@@ -256,6 +259,44 @@ static void cst816x_timer_stop(void *data)
 	timer_delete_sync(&priv->release_timer);
 }
 
+static int cst816x_panel_prepared(struct drm_panel_follower *follower)
+{
+	struct cst816x_priv *priv = container_of(follower, struct cst816x_priv,
+						 follower);
+
+	if (priv->reset)
+		cst816x_reset(priv);
+
+	enable_irq(priv->client->irq);
+
+	return 0;
+}
+
+static int cst816x_panel_unpreparing(struct drm_panel_follower *follower)
+{
+	struct cst816x_priv *priv = container_of(follower, struct cst816x_priv,
+						 follower);
+	unsigned long flags;
+
+	disable_irq(priv->client->irq);
+	timer_delete_sync(&priv->release_timer);
+
+	spin_lock_irqsave(&priv->lock, flags);
+
+	cst816x_release_keys(priv);
+	input_report_key(priv->input, BTN_TOUCH, 0);
+	input_sync(priv->input);
+
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return 0;
+}
+
+static const struct drm_panel_follower_funcs cst816x_panel_follower_funcs = {
+	.panel_prepared = cst816x_panel_prepared,
+	.panel_unpreparing = cst816x_panel_unpreparing,
+};
+
 static int cst816x_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -275,9 +316,6 @@ static int cst816x_probe(struct i2c_client *client)
 		return dev_err_probe(dev, PTR_ERR(priv->reset),
 				     "gpio reset request failed\n");
 
-	if (priv->reset)
-		cst816x_reset(priv);
-
 	error = cst816x_parse_keycodes(dev, priv);
 	if (error)
 		dev_warn(dev, "no gestures found in dt\n");
@@ -290,12 +328,24 @@ static int cst816x_probe(struct i2c_client *client)
 	if (error)
 		return error;
 
-	error = devm_request_threaded_irq(dev, client->irq,
-					  NULL, cst816x_irq_cb, IRQF_ONESHOT,
+	error = devm_request_threaded_irq(dev, client->irq, NULL,
+					  cst816x_irq_cb,
+					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
 					  dev_driver_string(dev), priv);
 	if (error)
 		return dev_err_probe(dev, error, "irq request failed\n");
 
+	if (drm_is_panel_follower(dev)) {
+		priv->follower.funcs = &cst816x_panel_follower_funcs;
+
+		return devm_drm_panel_add_follower(dev, &priv->follower);
+	}
+
+	if (priv->reset)
+		cst816x_reset(priv);
+
+	enable_irq(client->irq);
+
 	return 0;
 }
 
-- 
2.55.0