[PATCH v6 5/5] input: misc: pm8941-pwrkey: simulate missed key press events

From: Anjelique Melendez <quic_amelende@quicinc.com>
To: <dmitry.torokhov@gmail.com>, <corbet@lwn.net>, <sre@kernel.org>,
	<robh+dt@kernel.org>
Cc: <linux-input@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-arm-msm@vger.kernel.org>, <bjorn.andersson@linaro.org>,
	<swboyd@chromium.org>, <linux-doc@vger.kernel.org>,
	<linux-pm@vger.kernel.org>, <devicetree@vger.kernel.org>,
	David Collins <collinsd@codeaurora.org>,
	Anjelique Melendez <quic_amelende@quicinc.com>
Subject: [PATCH v6 5/5] input: misc: pm8941-pwrkey: simulate missed key press events
Date: Fri, 22 Apr 2022 12:12:43 -0700	[thread overview]
Message-ID: <20220422191239.6271-6-quic_amelende@quicinc.com> (raw)
In-Reply-To: <20220422191239.6271-1-quic_amelende@quicinc.com>

From: David Collins <collinsd@codeaurora.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@codeaurora.org>
Signed-off-by: Anjelique Melendez <quic_amelende@quicinc.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 881943ab4d55..3519152759dd 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);
 
-- 
2.35.1

