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

Dario Binacchi
2025-09-15T19:54:01Z

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