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

[Dario Binacchi <dario.binacchi@amarulasolutions.com>]

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