[PATCH 0/4] Input: imx6ul_tsc - set glitch threshold by dts property

[PATCH 0/4] Input: imx6ul_tsc - set glitch threshold by dts property

[Dario Binacchi]

The series allows setting the glitch threshold for the detected signal
from a DTS property instead of a hardcoded value.
In addition, I applied a patch that replaces opencoded masking and
shifting, with BIT(), GENMASK(), FIELD_GET() and FIELD_PREP() macros.


Dario Binacchi (3):
  dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add
    fsl,glitch-threshold
  Input: imx6ul_tsc - set glitch threshold by DTS property
  Input: imx6ul_tsc - use BIT, FIELD_{GET,PREP} and GENMASK macros

Michael Trimarchi (1):
  Input: imx6ul_tsc - fix typo in register name

 .../input/touchscreen/fsl,imx6ul-tsc.yaml     |  18 +++
 drivers/input/touchscreen/imx6ul_tsc.c        | 112 +++++++++++-------
 2 files changed, 86 insertions(+), 44 deletions(-)

-- 
2.43.0

base-commit: 89be9a83ccf1f88522317ce02f854f30d6115c41
branch: tsc_de_glitch

[PATCH 1/4] Input: imx6ul_tsc - fix typo in register name

[Dario Binacchi]

From: Michael Trimarchi <michael@amarulasolutions.com>

Replace 'SETING' with 'SETTING'.

Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 drivers/input/touchscreen/imx6ul_tsc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index 6ac8fa84ed9f..c2c6e50efc54 100644
--- a/drivers/input/touchscreen/imx6ul_tsc.c
+++ b/drivers/input/touchscreen/imx6ul_tsc.c
@@ -55,7 +55,7 @@
 #define ADC_TIMEOUT		msecs_to_jiffies(100)
 
 /* TSC registers */
-#define REG_TSC_BASIC_SETING	0x00
+#define REG_TSC_BASIC_SETTING	0x00
 #define REG_TSC_PRE_CHARGE_TIME	0x10
 #define REG_TSC_FLOW_CONTROL	0x20
 #define REG_TSC_MEASURE_VALUE	0x30
@@ -192,7 +192,7 @@ static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
 
 	basic_setting |= tsc->measure_delay_time << 8;
 	basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
-	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETING);
+	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETTING);
 
 	writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
 
-- 
2.43.0

[PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Dario Binacchi]

Add support for glitch threshold configuration. A detected signal is valid
only if it lasts longer than the set threshold; otherwise, it is regarded
as a glitch.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
index 678756ad0f92..2fee2940213f 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
@@ -62,6 +62,23 @@ properties:
     description: Number of data samples which are averaged for each read.
     enum: [ 1, 4, 8, 16, 32 ]
 
+  fsl,glitch-threshold:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 0
+    enum: [ 0, 1, 2, 3 ]
+    description: |
+      Indicates the glitch threshold. The threshold is defined by number
+      of clock cycles. A detect signal is only valid if it is exist longer
+      than threshold; otherwise, it is regarded as a glitch.
+      0: Normal function: 8191 clock cycles
+         Low power mode: 9 clock cycles
+      1: Normal function: 4095 clock cycles
+         Low power mode: 7 clock cycles
+      2: Normal function: 2047 clock cycles
+         Low power mode: 5 clock cycles
+      3: Normal function: 1023 clock cycles
+         Low power mode: 3 clock cycles
+
 required:
   - compatible
   - reg
@@ -94,4 +111,5 @@ examples:
         measure-delay-time = <0xfff>;
         pre-charge-time = <0xffff>;
         touchscreen-average-samples = <32>;
+        fsl,glitch-threshold = <2>;
     };
-- 
2.43.0

[PATCH 3/4] Input: imx6ul_tsc - set glitch threshold by DTS property

[Dario Binacchi]

Set the glitch threshold previously hardcoded in the driver. The change
is backward compatible.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 drivers/input/touchscreen/imx6ul_tsc.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index c2c6e50efc54..a6066643bd48 100644
--- a/drivers/input/touchscreen/imx6ul_tsc.c
+++ b/drivers/input/touchscreen/imx6ul_tsc.c
@@ -7,6 +7,7 @@
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/bitfield.h>
 #include <linux/gpio/consumer.h>
 #include <linux/input.h>
 #include <linux/slab.h>
@@ -74,7 +75,8 @@
 #define MEASURE_INT_EN		0x1
 #define MEASURE_SIG_EN		0x1
 #define VALID_SIG_EN		(0x1 << 8)
-#define DE_GLITCH_2		(0x2 << 29)
+#define DE_GLITCH_MASK		GENMASK(30, 29)
+#define DE_GLITCH_DEF		0x02
 #define START_SENSE		(0x1 << 12)
 #define TSC_DISABLE		(0x1 << 16)
 #define DETECT_MODE		0x2
@@ -92,6 +94,7 @@ struct imx6ul_tsc {
 	u32 pre_charge_time;
 	bool average_enable;
 	u32 average_select;
+	u32 de_glitch;
 
 	struct completion completion;
 };
@@ -188,13 +191,15 @@ static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
 static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
 {
 	u32 basic_setting = 0;
+	u32 debug_mode2;
 	u32 start;
 
 	basic_setting |= tsc->measure_delay_time << 8;
 	basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
 	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETTING);
 
-	writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
+	debug_mode2 = FIELD_PREP(DE_GLITCH_MASK, tsc->de_glitch);
+	writel(debug_mode2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
 
 	writel(tsc->pre_charge_time, tsc->tsc_regs + REG_TSC_PRE_CHARGE_TIME);
 	writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
@@ -501,6 +506,17 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	err = of_property_read_u32(np, "fsl,glitch-threshold", &tsc->de_glitch);
+	if (err)
+		tsc->de_glitch = DE_GLITCH_DEF;
+
+	if (tsc->de_glitch > FIELD_MAX(DE_GLITCH_MASK)) {
+		dev_err(&pdev->dev,
+			"fsl,glitch-threshold (%u) must be less or equal to %lu\n",
+			tsc->de_glitch, FIELD_MAX(DE_GLITCH_MASK));
+		return -EINVAL;
+	}
+
 	err = input_register_device(tsc->input);
 	if (err) {
 		dev_err(&pdev->dev,
-- 
2.43.0

[PATCH 4/4] Input: imx6ul_tsc - use BIT, FIELD_{GET,PREP} and GENMASK macros

[Dario Binacchi]

Replace opencoded masking and shifting, with BIT(), GENMASK(),
FIELD_GET() and FIELD_PREP() macros.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 drivers/input/touchscreen/imx6ul_tsc.c | 88 ++++++++++++++------------
 1 file changed, 48 insertions(+), 40 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index a6066643bd48..e74999c5e22f 100644
--- a/drivers/input/touchscreen/imx6ul_tsc.c
+++ b/drivers/input/touchscreen/imx6ul_tsc.c
@@ -21,25 +21,23 @@
 #include <linux/log2.h>
 
 /* ADC configuration registers field define */
-#define ADC_AIEN		(0x1 << 7)
+#define ADC_AIEN		BIT(7)
+#define ADC_ADCH_MASK		GENMASK(4, 0)
 #define ADC_CONV_DISABLE	0x1F
-#define ADC_AVGE		(0x1 << 5)
-#define ADC_CAL			(0x1 << 7)
-#define ADC_CALF		0x2
-#define ADC_12BIT_MODE		(0x2 << 2)
-#define ADC_CONV_MODE_MASK	(0x3 << 2)
+#define ADC_AVGE		BIT(5)
+#define ADC_CAL			BIT(7)
+#define ADC_CALF		BIT(1)
+#define ADC_CONV_MODE_MASK	GENMASK(3, 2)
+#define ADC_12BIT_MODE		0x2
 #define ADC_IPG_CLK		0x00
-#define ADC_INPUT_CLK_MASK	0x3
-#define ADC_CLK_DIV_8		(0x03 << 5)
-#define ADC_CLK_DIV_MASK	(0x3 << 5)
-#define ADC_SHORT_SAMPLE_MODE	(0x0 << 4)
-#define ADC_SAMPLE_MODE_MASK	(0x1 << 4)
-#define ADC_HARDWARE_TRIGGER	(0x1 << 13)
-#define ADC_AVGS_SHIFT		14
-#define ADC_AVGS_MASK		(0x3 << 14)
+#define ADC_INPUT_CLK_MASK	GENMASK(1, 0)
+#define ADC_CLK_DIV_8		0x03
+#define ADC_CLK_DIV_MASK	GENMASK(6, 5)
+#define ADC_SAMPLE_MODE		BIT(4)
+#define ADC_HARDWARE_TRIGGER	BIT(13)
+#define ADC_AVGS_MASK		GENMASK(15, 14)
 #define SELECT_CHANNEL_4	0x04
 #define SELECT_CHANNEL_1	0x01
-#define DISABLE_CONVERSION_INT	(0x0 << 7)
 
 /* ADC registers */
 #define REG_ADC_HC0		0x00
@@ -66,20 +64,26 @@
 #define REG_TSC_DEBUG_MODE	0x70
 #define REG_TSC_DEBUG_MODE2	0x80
 
+/* TSC_MEASURE_VALUE register field define */
+#define X_VALUE_MASK		GENMASK(27, 16)
+#define Y_VALUE_MASK		GENMASK(11, 0)
+
 /* TSC configuration registers field define */
-#define DETECT_4_WIRE_MODE	(0x0 << 4)
-#define AUTO_MEASURE		0x1
-#define MEASURE_SIGNAL		0x1
-#define DETECT_SIGNAL		(0x1 << 4)
-#define VALID_SIGNAL		(0x1 << 8)
-#define MEASURE_INT_EN		0x1
-#define MEASURE_SIG_EN		0x1
-#define VALID_SIG_EN		(0x1 << 8)
+#define MEASURE_DELAY_TIME_MASK	GENMASK(31, 8)
+#define DETECT_5_WIRE_MODE	BIT(4)
+#define AUTO_MEASURE		BIT(0)
+#define MEASURE_SIGNAL		BIT(0)
+#define DETECT_SIGNAL		BIT(4)
+#define VALID_SIGNAL		BIT(8)
+#define MEASURE_INT_EN		BIT(0)
+#define MEASURE_SIG_EN		BIT(0)
+#define VALID_SIG_EN		BIT(8)
 #define DE_GLITCH_MASK		GENMASK(30, 29)
 #define DE_GLITCH_DEF		0x02
-#define START_SENSE		(0x1 << 12)
-#define TSC_DISABLE		(0x1 << 16)
+#define START_SENSE		BIT(12)
+#define TSC_DISABLE		BIT(16)
 #define DETECT_MODE		0x2
+#define STATE_MACHINE_MASK	GENMASK(22, 20)
 
 struct imx6ul_tsc {
 	struct device *dev;
@@ -115,19 +119,20 @@ static int imx6ul_adc_init(struct imx6ul_tsc *tsc)
 
 	adc_cfg = readl(tsc->adc_regs + REG_ADC_CFG);
 	adc_cfg &= ~(ADC_CONV_MODE_MASK | ADC_INPUT_CLK_MASK);
-	adc_cfg |= ADC_12BIT_MODE | ADC_IPG_CLK;
-	adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE_MASK);
-	adc_cfg |= ADC_CLK_DIV_8 | ADC_SHORT_SAMPLE_MODE;
+	adc_cfg |= FIELD_PREP(ADC_CONV_MODE_MASK, ADC_12BIT_MODE) |
+		FIELD_PREP(ADC_INPUT_CLK_MASK, ADC_IPG_CLK);
+	adc_cfg &= ~(ADC_CLK_DIV_MASK | ADC_SAMPLE_MODE);
+	adc_cfg |= FIELD_PREP(ADC_CLK_DIV_MASK, ADC_CLK_DIV_8);
 	if (tsc->average_enable) {
 		adc_cfg &= ~ADC_AVGS_MASK;
-		adc_cfg |= (tsc->average_select) << ADC_AVGS_SHIFT;
+		adc_cfg |= FIELD_PREP(ADC_AVGS_MASK, tsc->average_select);
 	}
 	adc_cfg &= ~ADC_HARDWARE_TRIGGER;
 	writel(adc_cfg, tsc->adc_regs + REG_ADC_CFG);
 
 	/* enable calibration interrupt */
 	adc_hc |= ADC_AIEN;
-	adc_hc |= ADC_CONV_DISABLE;
+	adc_hc |= FIELD_PREP(ADC_ADCH_MASK, ADC_CONV_DISABLE);
 	writel(adc_hc, tsc->adc_regs + REG_ADC_HC0);
 
 	/* start ADC calibration */
@@ -167,19 +172,21 @@ static void imx6ul_tsc_channel_config(struct imx6ul_tsc *tsc)
 {
 	u32 adc_hc0, adc_hc1, adc_hc2, adc_hc3, adc_hc4;
 
-	adc_hc0 = DISABLE_CONVERSION_INT;
+	adc_hc0 = FIELD_PREP(ADC_AIEN, 0);
 	writel(adc_hc0, tsc->adc_regs + REG_ADC_HC0);
 
-	adc_hc1 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_4;
+	adc_hc1 = FIELD_PREP(ADC_AIEN, 0) |
+		FIELD_PREP(ADC_ADCH_MASK, SELECT_CHANNEL_4);
 	writel(adc_hc1, tsc->adc_regs + REG_ADC_HC1);
 
-	adc_hc2 = DISABLE_CONVERSION_INT;
+	adc_hc2 = FIELD_PREP(ADC_AIEN, 0);
 	writel(adc_hc2, tsc->adc_regs + REG_ADC_HC2);
 
-	adc_hc3 = DISABLE_CONVERSION_INT | SELECT_CHANNEL_1;
+	adc_hc3 = FIELD_PREP(ADC_AIEN, 0) |
+		FIELD_PREP(ADC_ADCH_MASK, SELECT_CHANNEL_1);
 	writel(adc_hc3, tsc->adc_regs + REG_ADC_HC3);
 
-	adc_hc4 = DISABLE_CONVERSION_INT;
+	adc_hc4 = FIELD_PREP(ADC_AIEN, 0);
 	writel(adc_hc4, tsc->adc_regs + REG_ADC_HC4);
 }
 
@@ -194,8 +201,9 @@ static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
 	u32 debug_mode2;
 	u32 start;
 
-	basic_setting |= tsc->measure_delay_time << 8;
-	basic_setting |= DETECT_4_WIRE_MODE | AUTO_MEASURE;
+	basic_setting |= FIELD_PREP(MEASURE_DELAY_TIME_MASK,
+				    tsc->measure_delay_time);
+	basic_setting |= AUTO_MEASURE;
 	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETTING);
 
 	debug_mode2 = FIELD_PREP(DE_GLITCH_MASK, tsc->de_glitch);
@@ -255,7 +263,7 @@ static bool tsc_wait_detect_mode(struct imx6ul_tsc *tsc)
 
 		usleep_range(200, 400);
 		debug_mode2 = readl(tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
-		state_machine = (debug_mode2 >> 20) & 0x7;
+		state_machine = FIELD_GET(STATE_MACHINE_MASK, debug_mode2);
 	} while (state_machine != DETECT_MODE);
 
 	usleep_range(200, 400);
@@ -283,8 +291,8 @@ static irqreturn_t tsc_irq_fn(int irq, void *dev_id)
 
 	if (status & MEASURE_SIGNAL) {
 		value = readl(tsc->tsc_regs + REG_TSC_MEASURE_VALUE);
-		x = (value >> 16) & 0x0fff;
-		y = value & 0x0fff;
+		x = FIELD_GET(X_VALUE_MASK, value);
+		y = FIELD_GET(Y_VALUE_MASK, value);
 
 		/*
 		 * In detect mode, we can get the xnur gpio value,
-- 
2.43.0

RE: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Bough Chen]

> -----Original Message-----
> From: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> Sent: 2025年7月22日 18:36
> To: linux-kernel@vger.kernel.org
> Cc: linux-amarula@amarulasolutions.com; Dario Binacchi
> <dario.binacchi@amarulasolutions.com>; Conor Dooley
> <conor+dt@kernel.org>; Dmitry Torokhov <dmitry.torokhov@gmail.com>;
> Fabio Estevam <festevam@gmail.com>; Bough Chen <haibo.chen@nxp.com>;
> Krzysztof Kozlowski <krzk+dt@kernel.org>; Pengutronix Kernel Team
> <kernel@pengutronix.de>; Rob Herring <robh@kernel.org>; Sascha Hauer
> <s.hauer@pengutronix.de>; Shawn Guo <shawnguo@kernel.org>;
> devicetree@vger.kernel.org; imx@lists.linux.dev;
> linux-arm-kernel@lists.infradead.org; linux-input@vger.kernel.org
> Subject: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add
> fsl,glitch-threshold
> 
> Add support for glitch threshold configuration. A detected signal is valid only if it
> lasts longer than the set threshold; otherwise, it is regarded as a glitch.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
>  .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git
> a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> index 678756ad0f92..2fee2940213f 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc
> +++ .yaml
> @@ -62,6 +62,23 @@ properties:
>      description: Number of data samples which are averaged for each read.
>      enum: [ 1, 4, 8, 16, 32 ]
> 
> +  fsl,glitch-threshold:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 0

Here the default should be 2 according to your third patch.

I'm okay for this patch set, let's waiting for comments about this yaml change.

By the way, any real case which need to use other glitch threshod?

Regards
Haibo Chen

> +    enum: [ 0, 1, 2, 3 ]
> +    description: |
> +      Indicates the glitch threshold. The threshold is defined by number
> +      of clock cycles. A detect signal is only valid if it is exist longer
> +      than threshold; otherwise, it is regarded as a glitch.
> +      0: Normal function: 8191 clock cycles
> +         Low power mode: 9 clock cycles
> +      1: Normal function: 4095 clock cycles
> +         Low power mode: 7 clock cycles
> +      2: Normal function: 2047 clock cycles
> +         Low power mode: 5 clock cycles
> +      3: Normal function: 1023 clock cycles
> +         Low power mode: 3 clock cycles
> +
>  required:
>    - compatible
>    - reg
> @@ -94,4 +111,5 @@ examples:
>          measure-delay-time = <0xfff>;
>          pre-charge-time = <0xffff>;
>          touchscreen-average-samples = <32>;
> +        fsl,glitch-threshold = <2>;
>      };
> --
> 2.43.0

Re: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Rob Herring]

On Tue, Jul 22, 2025 at 12:36:16PM +0200, Dario Binacchi wrote:
> Add support for glitch threshold configuration. A detected signal is valid
> only if it lasts longer than the set threshold; otherwise, it is regarded
> as a glitch.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> ---
> 
>  .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
>  1 file changed, 18 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> index 678756ad0f92..2fee2940213f 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> @@ -62,6 +62,23 @@ properties:
>      description: Number of data samples which are averaged for each read.
>      enum: [ 1, 4, 8, 16, 32 ]
>  
> +  fsl,glitch-threshold:
> +    $ref: /schemas/types.yaml#/definitions/uint32
> +    default: 0
> +    enum: [ 0, 1, 2, 3 ]
> +    description: |
> +      Indicates the glitch threshold. The threshold is defined by number
> +      of clock cycles. A detect signal is only valid if it is exist longer
> +      than threshold; otherwise, it is regarded as a glitch.
> +      0: Normal function: 8191 clock cycles
> +         Low power mode: 9 clock cycles
> +      1: Normal function: 4095 clock cycles
> +         Low power mode: 7 clock cycles
> +      2: Normal function: 2047 clock cycles
> +         Low power mode: 5 clock cycles
> +      3: Normal function: 1023 clock cycles
> +         Low power mode: 3 clock cycles

Don't we have common properties for this expressed in time? Debounce 
time IIRC.

> +
>  required:
>    - compatible
>    - reg
> @@ -94,4 +111,5 @@ examples:
>          measure-delay-time = <0xfff>;
>          pre-charge-time = <0xffff>;
>          touchscreen-average-samples = <32>;
> +        fsl,glitch-threshold = <2>;
>      };
> -- 
> 2.43.0
> 

Re: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Dario Binacchi]

Hi Bough,

On Wed, Jul 23, 2025 at 4:45 AM Bough Chen <haibo.chen@nxp.com> wrote:
>
> > -----Original Message-----
> > From: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> > Sent: 2025年7月22日 18:36
> > To: linux-kernel@vger.kernel.org
> > Cc: linux-amarula@amarulasolutions.com; Dario Binacchi
> > <dario.binacchi@amarulasolutions.com>; Conor Dooley
> > <conor+dt@kernel.org>; Dmitry Torokhov <dmitry.torokhov@gmail.com>;
> > Fabio Estevam <festevam@gmail.com>; Bough Chen <haibo.chen@nxp.com>;
> > Krzysztof Kozlowski <krzk+dt@kernel.org>; Pengutronix Kernel Team
> > <kernel@pengutronix.de>; Rob Herring <robh@kernel.org>; Sascha Hauer
> > <s.hauer@pengutronix.de>; Shawn Guo <shawnguo@kernel.org>;
> > devicetree@vger.kernel.org; imx@lists.linux.dev;
> > linux-arm-kernel@lists.infradead.org; linux-input@vger.kernel.org
> > Subject: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add
> > fsl,glitch-threshold
> >
> > Add support for glitch threshold configuration. A detected signal is valid only if it
> > lasts longer than the set threshold; otherwise, it is regarded as a glitch.
> >
> > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> > ---
> >
> >  .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > index 678756ad0f92..2fee2940213f 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc
> > +++ .yaml
> > @@ -62,6 +62,23 @@ properties:
> >      description: Number of data samples which are averaged for each read.
> >      enum: [ 1, 4, 8, 16, 32 ]
> >
> > +  fsl,glitch-threshold:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    default: 0
>
> Here the default should be 2 according to your third patch.

I considered the default value of the register, not the driver's.
If I'm not mistaken, the dt-bindings should be a description of the
hardware, not of the associated driver implementation.

>
> I'm okay for this patch set, let's waiting for comments about this yaml change.
>
> By the way, any real case which need to use other glitch threshod?

We recently submitted
https://lore.kernel.org/all/aGUDza5XRGDqfz5n@dragon/#t, and in this
initial contribution we removed all the custom parts that are not
supported upstream. This is
one such case. For our board, we need a de_glitch value of 1.

Thanks and regards,
Dario

>
> Regards
> Haibo Chen
>
> > +    enum: [ 0, 1, 2, 3 ]
> > +    description: |
> > +      Indicates the glitch threshold. The threshold is defined by number
> > +      of clock cycles. A detect signal is only valid if it is exist longer
> > +      than threshold; otherwise, it is regarded as a glitch.
> > +      0: Normal function: 8191 clock cycles
> > +         Low power mode: 9 clock cycles
> > +      1: Normal function: 4095 clock cycles
> > +         Low power mode: 7 clock cycles
> > +      2: Normal function: 2047 clock cycles
> > +         Low power mode: 5 clock cycles
> > +      3: Normal function: 1023 clock cycles
> > +         Low power mode: 3 clock cycles
> > +
> >  required:
> >    - compatible
> >    - reg
> > @@ -94,4 +111,5 @@ examples:
> >          measure-delay-time = <0xfff>;
> >          pre-charge-time = <0xffff>;
> >          touchscreen-average-samples = <32>;
> > +        fsl,glitch-threshold = <2>;
> >      };
> > --
> > 2.43.0
>


-- 

Dario Binacchi

Senior Embedded Linux Developer

dario.binacchi@amarulasolutions.com

__________________________________


Amarula Solutions SRL

Via Le Canevare 30, 31100 Treviso, Veneto, IT

T. +39 042 243 5310
info@amarulasolutions.com

www.amarulasolutions.com

Re: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Dario Binacchi]

On Wed, Jul 23, 2025 at 7:03 AM Rob Herring <robh@kernel.org> wrote:
>
> On Tue, Jul 22, 2025 at 12:36:16PM +0200, Dario Binacchi wrote:
> > Add support for glitch threshold configuration. A detected signal is valid
> > only if it lasts longer than the set threshold; otherwise, it is regarded
> > as a glitch.
> >
> > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> > ---
> >
> >  .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
> >  1 file changed, 18 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > index 678756ad0f92..2fee2940213f 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > @@ -62,6 +62,23 @@ properties:
> >      description: Number of data samples which are averaged for each read.
> >      enum: [ 1, 4, 8, 16, 32 ]
> >
> > +  fsl,glitch-threshold:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    default: 0
> > +    enum: [ 0, 1, 2, 3 ]
> > +    description: |
> > +      Indicates the glitch threshold. The threshold is defined by number
> > +      of clock cycles. A detect signal is only valid if it is exist longer
> > +      than threshold; otherwise, it is regarded as a glitch.
> > +      0: Normal function: 8191 clock cycles
> > +         Low power mode: 9 clock cycles
> > +      1: Normal function: 4095 clock cycles
> > +         Low power mode: 7 clock cycles
> > +      2: Normal function: 2047 clock cycles
> > +         Low power mode: 5 clock cycles
> > +      3: Normal function: 1023 clock cycles
> > +         Low power mode: 3 clock cycles
>
> Don't we have common properties for this expressed in time? Debounce
> time IIRC.

I tried checking in
Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml,
but I didn't find anything about it.

It exists in some specific touchscreen bindings:
- azoteq,iqs7211.yaml
- brcm,iproc-touchscreen.txt
- fsl-mx25-tcq.txt,
- ti,ads7843.yaml.

Only fsl-mx25-tcq.txt expresses it in terms of time (ns).

Thanks and regards,
Dario

>
> > +
> >  required:
> >    - compatible
> >    - reg
> > @@ -94,4 +111,5 @@ examples:
> >          measure-delay-time = <0xfff>;
> >          pre-charge-time = <0xffff>;
> >          touchscreen-average-samples = <32>;
> > +        fsl,glitch-threshold = <2>;
> >      };
> > --
> > 2.43.0
> >



-- 

Dario Binacchi

Senior Embedded Linux Developer

dario.binacchi@amarulasolutions.com

__________________________________


Amarula Solutions SRL

Via Le Canevare 30, 31100 Treviso, Veneto, IT

T. +39 042 243 5310
info@amarulasolutions.com

www.amarulasolutions.com

Re: [PATCH 2/4] dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add fsl,glitch-threshold

[Dario Binacchi]

Hello Rob,

just a gentle ping — I’ve replied to your comments on this patch, but
I haven’t seen any further feedback.

Thanks and regards,
Dario

On Wed, Jul 23, 2025 at 8:25 AM Dario Binacchi
<dario.binacchi@amarulasolutions.com> wrote:
>
> On Wed, Jul 23, 2025 at 7:03 AM Rob Herring <robh@kernel.org> wrote:
> >
> > On Tue, Jul 22, 2025 at 12:36:16PM +0200, Dario Binacchi wrote:
> > > Add support for glitch threshold configuration. A detected signal is valid
> > > only if it lasts longer than the set threshold; otherwise, it is regarded
> > > as a glitch.
> > >
> > > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> > > ---
> > >
> > >  .../input/touchscreen/fsl,imx6ul-tsc.yaml      | 18 ++++++++++++++++++
> > >  1 file changed, 18 insertions(+)
> > >
> > > diff --git a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > index 678756ad0f92..2fee2940213f 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > @@ -62,6 +62,23 @@ properties:
> > >      description: Number of data samples which are averaged for each read.
> > >      enum: [ 1, 4, 8, 16, 32 ]
> > >
> > > +  fsl,glitch-threshold:
> > > +    $ref: /schemas/types.yaml#/definitions/uint32
> > > +    default: 0
> > > +    enum: [ 0, 1, 2, 3 ]
> > > +    description: |
> > > +      Indicates the glitch threshold. The threshold is defined by number
> > > +      of clock cycles. A detect signal is only valid if it is exist longer
> > > +      than threshold; otherwise, it is regarded as a glitch.
> > > +      0: Normal function: 8191 clock cycles
> > > +         Low power mode: 9 clock cycles
> > > +      1: Normal function: 4095 clock cycles
> > > +         Low power mode: 7 clock cycles
> > > +      2: Normal function: 2047 clock cycles
> > > +         Low power mode: 5 clock cycles
> > > +      3: Normal function: 1023 clock cycles
> > > +         Low power mode: 3 clock cycles
> >
> > Don't we have common properties for this expressed in time? Debounce
> > time IIRC.
>
> I tried checking in
> Documentation/devicetree/bindings/input/touchscreen/touchscreen.yaml,
> but I didn't find anything about it.
>
> It exists in some specific touchscreen bindings:
> - azoteq,iqs7211.yaml
> - brcm,iproc-touchscreen.txt
> - fsl-mx25-tcq.txt,
> - ti,ads7843.yaml.
>
> Only fsl-mx25-tcq.txt expresses it in terms of time (ns).
>
> Thanks and regards,
> Dario
>
> >
> > > +
> > >  required:
> > >    - compatible
> > >    - reg
> > > @@ -94,4 +111,5 @@ examples:
> > >          measure-delay-time = <0xfff>;
> > >          pre-charge-time = <0xffff>;
> > >          touchscreen-average-samples = <32>;
> > > +        fsl,glitch-threshold = <2>;
> > >      };
> > > --
> > > 2.43.0
> > >
>
>
>
> --
>
> Dario Binacchi
>
> Senior Embedded Linux Developer
>
> dario.binacchi@amarulasolutions.com
>
> __________________________________
>
>
> Amarula Solutions SRL
>
> Via Le Canevare 30, 31100 Treviso, Veneto, IT
>
> T. +39 042 243 5310
> info@amarulasolutions.com
>
> www.amarulasolutions.com



-- 

Dario Binacchi

Senior Embedded Linux Developer

dario.binacchi@amarulasolutions.com

__________________________________


Amarula Solutions SRL

Via Le Canevare 30, 31100 Treviso, Veneto, IT

T. +39 042 243 5310
info@amarulasolutions.com

www.amarulasolutions.com