[PATCH v3 0/6] Input: imx6ul_tsc - set glitch threshold by dts property

[PATCH v3 0/6] 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.

Changes in v3:
- Remove the final part of the description that refers to
  implementation details in fsl,imx6ul-tsc.yaml.

Changes in v2:
- Replace patch ("dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add
  fsl,glitch-threshold") with ("dt-bindings: touchscreen: add
  touchscreen-glitch-threshold-ns property"), making the previous property
  general by moving it to touchscreen.yaml.
- Rework "Input: imx6ul_tsc - set glitch threshold by DTS property" patch
  to match changes made to the DTS property.
- Move "Input: imx6ul_tsc - use BIT, FIELD_{GET,PREP} and GENMASK macros"
  patch right after the patch fixing the typo.

Dario Binacchi (5):
  Input: imx6ul_tsc - use BIT, FIELD_{GET,PREP} and GENMASK macros
  dt-bindings: touchscreen: add touchscreen-glitch-threshold-ns property
  dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold
  ARM: dts: imx6ull-engicam-microgea-bmm: set touchscreen glitch
    threshold
  Input: imx6ul_tsc - set glitch threshold by DTS property

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

 .../input/touchscreen/fsl,imx6ul-tsc.yaml     |  12 ++
 .../input/touchscreen/touchscreen.yaml        |   4 +
 .../nxp/imx/imx6ull-engicam-microgea-bmm.dts  |   1 +
 drivers/input/touchscreen/imx6ul_tsc.c        | 122 +++++++++++-------
 4 files changed, 95 insertions(+), 44 deletions(-)

-- 
2.43.0

base-commit: f83ec76bf285bea5727f478a68b894f5543ca76e
branch: tsc_de_glitch

[PATCH v3 1/6] 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>
Reviewed-by: Frank Li <Frank.Li@nxp.com>

---

(no changes since v2)

Changes in v2:
- Add Reviewed-by tag of Frank Li.

 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 v3 2/6] 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>
Reviewed-by: Frank Li <Frank.Li@nxp.com>

---

(no changes since v2)

Changes in v2:
- Add Reviewed-by tag of Frank Li.
- Move the patch right after the one fixing the typo according
  to Frank Li's suggestions.

 drivers/input/touchscreen/imx6ul_tsc.c | 96 +++++++++++++++-----------
 1 file changed, 54 insertions(+), 42 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index c2c6e50efc54..e2c59cc7c82c 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>
@@ -20,25 +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
@@ -65,19 +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 DE_GLITCH_2		(0x2 << 29)
-#define START_SENSE		(0x1 << 12)
-#define TSC_DISABLE		(0x1 << 16)
+#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_2		0x02
+#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;
@@ -112,19 +118,20 @@ 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 */
@@ -164,19 +171,21 @@ 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);
 }
 
@@ -188,13 +197,16 @@ 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;
+	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);
 
-	writel(DE_GLITCH_2, tsc->tsc_regs + REG_TSC_DEBUG_MODE2);
+	debug_mode2 = FIELD_PREP(DE_GLITCH_MASK, DE_GLITCH_2);
+	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);
@@ -250,7 +262,7 @@ 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);
@@ -278,8 +290,8 @@ 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

[PATCH v3 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Dario Binacchi]

Support the touchscreen-glitch-threshold-ns property. Unlike the
generic description in touchscreen.yaml, this controller maps the
provided value to one of four discrete thresholds internally.

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

---

Changes in v3:
- Remove the final part of the description that refers to
  implementation details.

 .../bindings/input/touchscreen/fsl,imx6ul-tsc.yaml   | 12 ++++++++++++
 1 file changed, 12 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..6214d8be5a99 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
@@ -62,6 +62,18 @@ properties:
     description: Number of data samples which are averaged for each read.
     enum: [ 1, 4, 8, 16, 32 ]
 
+  touchscreen-glitch-threshold-ns:
+    description: |
+      Unlike the generic property defined in touchscreen.yaml, this
+      controller does not allow arbitrary values. Internally the value is
+      converted to IPG clock cycles and mapped to one of four discrete
+      thresholds exposed by the TSC_DEBUG_MODE2 register:
+
+        0: 8191 IPG cycles
+        1: 4095 IPG cycles
+        2: 2047 IPG cycles
+        3: 1023 IPG cycles
+
 required:
   - compatible
   - reg
-- 
2.43.0

[PATCH v3 5/6] ARM: dts: imx6ull-engicam-microgea-bmm: set touchscreen glitch threshold

[Dario Binacchi]

This way the detected signal is valid only if it lasts longer than
62 µs, otherwise it is not sampled.

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

(no changes since v1)

 arch/arm/boot/dts/nxp/imx/imx6ull-engicam-microgea-bmm.dts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/nxp/imx/imx6ull-engicam-microgea-bmm.dts b/arch/arm/boot/dts/nxp/imx/imx6ull-engicam-microgea-bmm.dts
index 279d46c22cd7..f12084d8f2a0 100644
--- a/arch/arm/boot/dts/nxp/imx/imx6ull-engicam-microgea-bmm.dts
+++ b/arch/arm/boot/dts/nxp/imx/imx6ull-engicam-microgea-bmm.dts
@@ -154,6 +154,7 @@ &tsc {
 	pinctrl-0 = <&pinctrl_tsc>;
 	measure-delay-time = <0x9ffff>;
 	pre-charge-time = <0xfff>;
+	touchscreen-glitch-threshold-ns = <62000>;
 	xnur-gpios = <&gpio1 3 GPIO_ACTIVE_LOW>;
 	status = "okay";
 };
-- 
2.43.0

[PATCH v3 6/6] 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>

---

Changes in v3:
- Remove the final part of the description that refers to
  implementation details in fsl,imx6ul-tsc.yaml.

Changes in v2:
- Replace patch ("dt-bindings: input: touchscreen: fsl,imx6ul-tsc: add
  fsl,glitch-threshold") with ("dt-bindings: touchscreen: add
  touchscreen-glitch-threshold-ns property"), making the previous property
  general by moving it to touchscreen.yaml.
- Rework "Input: imx6ul_tsc - set glitch threshold by DTS property" patch
  to match changes made to the DTS property.
- Move "Input: imx6ul_tsc - use BIT, FIELD_{GET,PREP} and GENMASK macros"
  patch right after the patch fixing the typo.
- Rework to match changes made to the DTS property.

 drivers/input/touchscreen/imx6ul_tsc.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index e2c59cc7c82c..0d753aa05fbf 100644
--- a/drivers/input/touchscreen/imx6ul_tsc.c
+++ b/drivers/input/touchscreen/imx6ul_tsc.c
@@ -79,7 +79,7 @@
 #define MEASURE_SIG_EN		BIT(0)
 #define VALID_SIG_EN		BIT(8)
 #define DE_GLITCH_MASK		GENMASK(30, 29)
-#define DE_GLITCH_2		0x02
+#define DE_GLITCH_DEF		0x02
 #define START_SENSE		BIT(12)
 #define TSC_DISABLE		BIT(16)
 #define DETECT_MODE		0x2
@@ -98,6 +98,7 @@ struct imx6ul_tsc {
 	u32 pre_charge_time;
 	bool average_enable;
 	u32 average_select;
+	u32 de_glitch;
 
 	struct completion completion;
 };
@@ -205,7 +206,7 @@ static void imx6ul_tsc_set(struct imx6ul_tsc *tsc)
 	basic_setting |= AUTO_MEASURE;
 	writel(basic_setting, tsc->tsc_regs + REG_TSC_BASIC_SETTING);
 
-	debug_mode2 = FIELD_PREP(DE_GLITCH_MASK, DE_GLITCH_2);
+	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);
@@ -391,6 +392,7 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
 	int tsc_irq;
 	int adc_irq;
 	u32 average_samples;
+	u32 de_glitch;
 
 	tsc = devm_kzalloc(&pdev->dev, sizeof(*tsc), GFP_KERNEL);
 	if (!tsc)
@@ -513,6 +515,26 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	err = of_property_read_u32(np, "touchscreen-glitch-threshold-ns",
+				   &de_glitch);
+	if (err) {
+		tsc->de_glitch = DE_GLITCH_DEF;
+	} else {
+		u64 cycles;
+		unsigned long rate = clk_get_rate(tsc->tsc_clk);
+
+		cycles = DIV64_U64_ROUND_UP((u64)de_glitch * rate, NSEC_PER_SEC);
+
+		if (cycles <= 0x3ff)
+			tsc->de_glitch = 3;
+		else if (cycles <= 0x7ff)
+			tsc->de_glitch = 2;
+		else if (cycles <= 0xfff)
+			tsc->de_glitch = 1;
+		else
+			tsc->de_glitch = 0;
+	}
+
 	err = input_register_device(tsc->input);
 	if (err) {
 		dev_err(&pdev->dev,
-- 
2.43.0

Re: [PATCH v3 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Frank Li]

On Mon, Sep 15, 2025 at 09:53:06PM +0200, Dario Binacchi wrote:
> Support the touchscreen-glitch-threshold-ns property. Unlike the
> generic description in touchscreen.yaml, this controller maps the
> provided value to one of four discrete thresholds internally.
>
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
>
> ---
>
> Changes in v3:
> - Remove the final part of the description that refers to
>   implementation details.
>
>  .../bindings/input/touchscreen/fsl,imx6ul-tsc.yaml   | 12 ++++++++++++
>  1 file changed, 12 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..6214d8be5a99 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> @@ -62,6 +62,18 @@ properties:
>      description: Number of data samples which are averaged for each read.
>      enum: [ 1, 4, 8, 16, 32 ]
>
> +  touchscreen-glitch-threshold-ns:
> +    description: |
> +      Unlike the generic property defined in touchscreen.yaml, this
> +      controller does not allow arbitrary values. Internally the value is
> +      converted to IPG clock cycles and mapped to one of four discrete
> +      thresholds exposed by the TSC_DEBUG_MODE2 register:
> +
> +        0: 8191 IPG cycles
> +        1: 4095 IPG cycles
> +        2: 2047 IPG cycles
> +        3: 1023 IPG cycles
> +

You have to use ns here. You can caculate in driver to match to closed one.

Frank

>  required:
>    - compatible
>    - reg
> --
> 2.43.0
>

Re: [PATCH v3 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2443 bytes --]

On Tue, Sep 16, 2025 at 11:55:17AM -0400, Frank Li wrote:
> On Mon, Sep 15, 2025 at 09:53:06PM +0200, Dario Binacchi wrote:
> > Support the touchscreen-glitch-threshold-ns property. Unlike the
> > generic description in touchscreen.yaml, this controller maps the
> > provided value to one of four discrete thresholds internally.
> >
> > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> >
> > ---
> >
> > Changes in v3:
> > - Remove the final part of the description that refers to
> >   implementation details.
> >
> >  .../bindings/input/touchscreen/fsl,imx6ul-tsc.yaml   | 12 ++++++++++++
> >  1 file changed, 12 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..6214d8be5a99 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > @@ -62,6 +62,18 @@ properties:
> >      description: Number of data samples which are averaged for each read.
> >      enum: [ 1, 4, 8, 16, 32 ]
> >
> > +  touchscreen-glitch-threshold-ns:
> > +    description: |
> > +      Unlike the generic property defined in touchscreen.yaml, this
> > +      controller does not allow arbitrary values. Internally the value is
> > +      converted to IPG clock cycles and mapped to one of four discrete
> > +      thresholds exposed by the TSC_DEBUG_MODE2 register:
> > +
> > +        0: 8191 IPG cycles
> > +        1: 4095 IPG cycles
> > +        2: 2047 IPG cycles
> > +        3: 1023 IPG cycles
> > +
> 
> You have to use ns here. You can caculate in driver to match to closed one.

That is what he is saying it is doing - "internally the value is
converted to IPG clock cycles" and so on. Your repeated misunderstanding
of this though points out that maybe the description is still lacking?

Dario, how about:
| The gitch threshold in nanoseconds. Drivers must convert this value to
| IPG clock cycles and map it to one of the four discrete thresholds
| exposed by the TSC_DEBUG_MODE2 register:
| 
|         0: 8191 IPG cycles
|         1: 4095 IPG cycles
|         2: 2047 IPG cycles
|         3: 1023 IPG cycles
? 
I dropped the bit about arbitrary values, due to my comment on the other
version a few mins ago.

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Re: [PATCH v3 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Conor Dooley]

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On Tue, Sep 16, 2025 at 08:25:53PM +0100, Conor Dooley wrote:
> On Tue, Sep 16, 2025 at 11:55:17AM -0400, Frank Li wrote:
> > On Mon, Sep 15, 2025 at 09:53:06PM +0200, Dario Binacchi wrote:
> > > Support the touchscreen-glitch-threshold-ns property. Unlike the
> > > generic description in touchscreen.yaml, this controller maps the
> > > provided value to one of four discrete thresholds internally.
> > >
> > > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> > >
> > > ---
> > >
> > > Changes in v3:
> > > - Remove the final part of the description that refers to
> > >   implementation details.
> > >
> > >  .../bindings/input/touchscreen/fsl,imx6ul-tsc.yaml   | 12 ++++++++++++
> > >  1 file changed, 12 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..6214d8be5a99 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > @@ -62,6 +62,18 @@ properties:
> > >      description: Number of data samples which are averaged for each read.
> > >      enum: [ 1, 4, 8, 16, 32 ]
> > >
> > > +  touchscreen-glitch-threshold-ns:
> > > +    description: |
> > > +      Unlike the generic property defined in touchscreen.yaml, this
> > > +      controller does not allow arbitrary values. Internally the value is
> > > +      converted to IPG clock cycles and mapped to one of four discrete
> > > +      thresholds exposed by the TSC_DEBUG_MODE2 register:
> > > +
> > > +        0: 8191 IPG cycles
> > > +        1: 4095 IPG cycles
> > > +        2: 2047 IPG cycles
> > > +        3: 1023 IPG cycles
> > > +
> > 
> > You have to use ns here. You can caculate in driver to match to closed one.
> 
> That is what he is saying it is doing - "internally the value is
> converted to IPG clock cycles" and so on. Your repeated misunderstanding
> of this though points out that maybe the description is still lacking?
> 
> Dario, how about:
> | The gitch threshold in nanoseconds. Drivers must convert this value to

Or maybe instead of what I did here for the first sentence, yoink the text
from [3/6] instead and re-use it.

> | IPG clock cycles and map it to one of the four discrete thresholds
> | exposed by the TSC_DEBUG_MODE2 register:
> | 
> |         0: 8191 IPG cycles
> |         1: 4095 IPG cycles
> |         2: 2047 IPG cycles
> |         3: 1023 IPG cycles
> ? 
> I dropped the bit about arbitrary values, due to my comment on the other
> version a few mins ago.



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