linux-kernel - [PATCH 3/4] Input: imx6ul_tsc - set glitch threshold by DTS property

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Message-ID: <20250722103706.3440777-4-dario.binacchi@amarulasolutions.com>
Date: Tue, 22 Jul 2025 12:36:17 +0200
From: Dario Binacchi <dario.binacchi@...rulasolutions.com>
To: linux-kernel@...r.kernel.org
Cc: linux-amarula@...rulasolutions.com,
	Dario Binacchi <dario.binacchi@...rulasolutions.com>,
	Dmitry Torokhov <dmitry.torokhov@...il.com>,
	Fabio Estevam <festevam@...il.com>,
	Michael Trimarchi <michael@...rulasolutions.com>,
	Pengutronix Kernel Team <kernel@...gutronix.de>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Shawn Guo <shawnguo@...nel.org>,
	imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org,
	linux-input@...r.kernel.org
Subject: [PATCH 3/4] Input: imx6ul_tsc - set glitch threshold by DTS property

Set the glitch threshold previously hardcoded in the driver. The change
is backward compatible.

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

 drivers/input/touchscreen/imx6ul_tsc.c | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/drivers/input/touchscreen/imx6ul_tsc.c b/drivers/input/touchscreen/imx6ul_tsc.c
index c2c6e50efc54..a6066643bd48 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>
@@ -74,7 +75,8 @@
 #define MEASURE_INT_EN		0x1
 #define MEASURE_SIG_EN		0x1
 #define VALID_SIG_EN		(0x1 << 8)
-#define DE_GLITCH_2		(0x2 << 29)
+#define DE_GLITCH_MASK		GENMASK(30, 29)
+#define DE_GLITCH_DEF		0x02
 #define START_SENSE		(0x1 << 12)
 #define TSC_DISABLE		(0x1 << 16)
 #define DETECT_MODE		0x2
@@ -92,6 +94,7 @@ struct imx6ul_tsc {
 	u32 pre_charge_time;
 	bool average_enable;
 	u32 average_select;
+	u32 de_glitch;
 
 	struct completion completion;
 };
@@ -188,13 +191,15 @@ 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;
 	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, 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);
 	writel(MEASURE_INT_EN, tsc->tsc_regs + REG_TSC_INT_EN);
@@ -501,6 +506,17 @@ static int imx6ul_tsc_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
+	err = of_property_read_u32(np, "fsl,glitch-threshold", &tsc->de_glitch);
+	if (err)
+		tsc->de_glitch = DE_GLITCH_DEF;
+
+	if (tsc->de_glitch > FIELD_MAX(DE_GLITCH_MASK)) {
+		dev_err(&pdev->dev,
+			"fsl,glitch-threshold (%u) must be less or equal to %lu\n",
+			tsc->de_glitch, FIELD_MAX(DE_GLITCH_MASK));
+		return -EINVAL;
+	}
+
 	err = input_register_device(tsc->input);
 	if (err) {
 		dev_err(&pdev->dev,
-- 
2.43.0