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

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:

quoted

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.