[PATCH v2 0/6] Input: imx6ul_tsc - set glitch threshold by dts property

[PATCH v2 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 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     |  15 +++
 .../input/touchscreen/touchscreen.yaml        |   4 +
 .../nxp/imx/imx6ull-engicam-microgea-bmm.dts  |   1 +
 drivers/input/touchscreen/imx6ul_tsc.c        | 122 +++++++++++-------
 4 files changed, 98 insertions(+), 44 deletions(-)

-- 
2.43.0

base-commit: df86f912b45c20e236060321c85fe35437e9325d
branch: tsc_de_glitch

[PATCH v2 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>

---

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 v2 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>

---

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 v2 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>
---

(no changes since v1)

 .../input/touchscreen/fsl,imx6ul-tsc.yaml         | 15 +++++++++++++++
 1 file changed, 15 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..310af56a0be6 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
@@ -62,6 +62,21 @@ 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
+
+      Any value provided in device tree is converted to cycles and rounded
+      up to the next supported threshold, or to 8191 if above 4095.
+
 required:
   - compatible
   - reg
-- 
2.43.0

[PATCH v2 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 v2 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 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 v2 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Frank Li]

On Sun, Sep 14, 2025 at 07:16:01PM +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>
> ---
>
> (no changes since v1)
>
>  .../input/touchscreen/fsl,imx6ul-tsc.yaml         | 15 +++++++++++++++
>  1 file changed, 15 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..310af56a0be6 100644
> --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> @@ -62,6 +62,21 @@ 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 should use ns
   enum:
      - 1023
      - 2047
      - 4095
      - 8191

you can limit only 4 values, but unit have to ns. your driver map it to
register value.

Frank

> +
> +      Any value provided in device tree is converted to cycles and rounded
> +      up to the next supported threshold, or to 8191 if above 4095.
> +
>  required:
>    - compatible
>    - reg
> --
> 2.43.0
>

Re: [PATCH v2 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2394 bytes --]

On Mon, Sep 15, 2025 at 10:30:26AM -0400, Frank Li wrote:
> On Sun, Sep 14, 2025 at 07:16:01PM +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>
> > ---
> >
> > (no changes since v1)
> >
> >  .../input/touchscreen/fsl,imx6ul-tsc.yaml         | 15 +++++++++++++++
> >  1 file changed, 15 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..310af56a0be6 100644
> > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > @@ -62,6 +62,21 @@ 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 should use ns
>    enum:
>       - 1023
>       - 2047
>       - 4095
>       - 8191
> 
> you can limit only 4 values, but unit have to ns. your driver map it to
> register value.

Looking at the driver change, I think Dario is already doing that. The
text here is just talking about how the controller doesn't support
anything other than these 4 glitch threshold and mapping must be done in
some way.

> > +
> > +      Any value provided in device tree is converted to cycles and rounded
> > +      up to the next supported threshold, or to 8191 if above 4095.

This seems to be the implementation details of one particular driver,
and does not belong in a binding.

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

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]

Re: [PATCH v2 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Frank Li]

On Mon, Sep 15, 2025 at 06:42:13PM +0100, Conor Dooley wrote:
> On Mon, Sep 15, 2025 at 10:30:26AM -0400, Frank Li wrote:
> > On Sun, Sep 14, 2025 at 07:16:01PM +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>
> > > ---
> > >
> > > (no changes since v1)
> > >
> > >  .../input/touchscreen/fsl,imx6ul-tsc.yaml         | 15 +++++++++++++++
> > >  1 file changed, 15 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..310af56a0be6 100644
> > > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > @@ -62,6 +62,21 @@ 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 should use ns
> >    enum:
> >       - 1023
> >       - 2047
> >       - 4095
> >       - 8191
> >
> > you can limit only 4 values, but unit have to ns. your driver map it to
> > register value.
>
> Looking at the driver change, I think Dario is already doing that. The
> text here is just talking about how the controller doesn't support
> anything other than these 4 glitch threshold and mapping must be done in
> some way.

Thanks, but descripton is confused.
"Unlike the generic property defined in touchscreen.yaml", which let me
think value is 0..3, instead of ns.

Suggest Remove

"Unlike the generic property defined in touchscreen.yaml, this
controller does not allow arbitrary values"

Frank
>
> > > +
> > > +      Any value provided in device tree is converted to cycles and rounded
> > > +      up to the next supported threshold, or to 8191 if above 4095.
>
> This seems to be the implementation details of one particular driver,
> and does not belong in a binding.
>
> > > +
> > >  required:
> > >    - compatible
> > >    - reg
> > > --
> > > 2.43.0
> > >

Re: [PATCH v2 4/6] dt-bindings: touchscreen: fsl,imx6ul-tsc: support glitch thresold

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 2796 bytes --]

On Tue, Sep 16, 2025 at 12:03:01PM -0400, Frank Li wrote:
> On Mon, Sep 15, 2025 at 06:42:13PM +0100, Conor Dooley wrote:
> > On Mon, Sep 15, 2025 at 10:30:26AM -0400, Frank Li wrote:
> > > On Sun, Sep 14, 2025 at 07:16:01PM +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>
> > > > ---
> > > >
> > > > (no changes since v1)
> > > >
> > > >  .../input/touchscreen/fsl,imx6ul-tsc.yaml         | 15 +++++++++++++++
> > > >  1 file changed, 15 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..310af56a0be6 100644
> > > > --- a/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > > +++ b/Documentation/devicetree/bindings/input/touchscreen/fsl,imx6ul-tsc.yaml
> > > > @@ -62,6 +62,21 @@ 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 should use ns
> > >    enum:
> > >       - 1023
> > >       - 2047
> > >       - 4095
> > >       - 8191
> > >
> > > you can limit only 4 values, but unit have to ns. your driver map it to
> > > register value.
> >
> > Looking at the driver change, I think Dario is already doing that. The
> > text here is just talking about how the controller doesn't support
> > anything other than these 4 glitch threshold and mapping must be done in
> > some way.
> 
> Thanks, but descripton is confused.
> "Unlike the generic property defined in touchscreen.yaml", which let me
> think value is 0..3, instead of ns.
> 
> Suggest Remove
> 
> "Unlike the generic property defined in touchscreen.yaml, this
> controller does not allow arbitrary values"

Yeah, I agree this should be removed. It's unlikely that /any/
touchscreen will support completely arbitrary values, so stating it is
redundant.

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]