Re: [PATCH v4 6/6] Input: imx6ul_tsc - set glitch threshold by DTS property
flat view
From: Frank Li <Frank.li@nxp.com>
Date: 2025-09-17 16:21:08
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imx, linux-input, lkml
On Wed, Sep 17, 2025 at 10:05:11AM +0200, Dario Binacchi wrote:
Set the glitch threshold previously hardcoded in the driver. The change is backward compatible.
Set the glitch threshold by DTS property and keep the existing default behavior if the 'touchscreen-glitch-threshold-ns' not present. Reviewed-by: Frank Li <Frank.Li@nxp.com>
quoted hunk ↗ jump to hunk
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> --- Changes in v4: - Adjust property description fsl,imx6ul-tsc.yaml following the suggestions of Conor Dooley and Frank Li. 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