linux-kernel - [PATCH v3 4/4] input: misc: pm8941-pwrkey: simulate missed key press events

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Message-ID: <20220203010804.20883-5-quic_amelende@quicinc.com>
Date:   Wed, 2 Feb 2022 17:08:09 -0800
From:   Anjelique Melendez <quic_amelende@...cinc.com>
To:     <dmitry.torokhov@...il.com>
CC:     <linux-input@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
        <linux-arm-msm@...r.kernel.org>, <collinsd@...eaurora.org>,
        <bjorn.andersson@...aro.org>, <swboyd@...omium.org>,
        <skakit@...eaurora.org>,
        Anjelique Melendez <quic_amelende@...cinc.com>
Subject: [PATCH v3 4/4] input: misc: pm8941-pwrkey: simulate missed key press events

From: David Collins <collinsd@...eaurora.org>

The status of the keys connected to the KPDPWR_N and RESIN_N pins
is identified by reading corresponding bits in the interrupt real
time status register.  If the status has changed by the time that
the interrupt is handled then a press event will be missed.

Maintain a last known status variable to find unbalanced release
events and simulate press events for each accordingly.

Signed-off-by: David Collins <collinsd@...eaurora.org>
Signed-off-by: Anjelique Melendez <quic_amelende@...cinc.com>
---
 drivers/input/misc/pm8941-pwrkey.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/input/misc/pm8941-pwrkey.c b/drivers/input/misc/pm8941-pwrkey.c
index 4768a542777d..60de6581af21 100644
--- a/drivers/input/misc/pm8941-pwrkey.c
+++ b/drivers/input/misc/pm8941-pwrkey.c
@@ -76,6 +76,7 @@ struct pm8941_pwrkey {
 	u32 code;
 	u32 sw_debounce_time_us;
 	ktime_t sw_debounce_end_time;
+	bool last_status;
 	const struct pm8941_data *data;
 };
 
@@ -162,6 +163,16 @@ static irqreturn_t pm8941_pwrkey_irq(int irq, void *_data)
 		pwrkey->sw_debounce_end_time = ktime_add_us(ktime_get(),
 						pwrkey->sw_debounce_time_us);
 
+	/*
+	 * Simulate a press event in case a release event occurred without a
+	 * corresponding press event.
+	 */
+	if (!pwrkey->last_status && !sts) {
+		input_report_key(pwrkey->input, pwrkey->code, 1);
+		input_sync(pwrkey->input);
+	}
+	pwrkey->last_status = sts;
+
 	input_report_key(pwrkey->input, pwrkey->code, sts);
 	input_sync(pwrkey->input);
 
-- 
2.34.1