linux-kernel - Re: [PATCH 3/5] Input: omap4-keypad - move rest of key scanning to a separate function

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Date:   Sun, 10 Jan 2021 20:50:44 -0800
From:   Dmitry Torokhov <dmitry.torokhov@...il.com>
To:     Tony Lindgren <tony@...mide.com>
Cc:     linux-input@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-omap@...r.kernel.org,
        Arthur Demchenkov <spinal.by@...il.com>,
        Carl Philipp Klemm <philipp@...s.xyz>,
        Merlijn Wajer <merlijn@...zup.org>,
        Pavel Machek <pavel@....cz>, ruleh <ruleh@....de>,
        Sebastian Reichel <sre@...nel.org>
Subject: Re: [PATCH 3/5] Input: omap4-keypad - move rest of key scanning to a
 separate function

On Sun, Jan 10, 2021 at 09:05:27PM +0200, Tony Lindgren wrote:
> Let's move rest of the key scanning code to omap4_keypad_scan_keys().
> We will use omap4_keypad_scan_keys() also for implementing errata
> handling to clear the stuck last key in the following patch.

And this one will become then...

-- 
Dmitry


Input: omap4-keypad - move rest of key scanning to a separate function

From: Tony Lindgren <tony@...mide.com>

Let's move rest of the key scanning code to omap4_keypad_scan_keys().
We will use omap4_keypad_scan_keys() also for implementing errata
handling to clear the stuck last key in the following patch.

Signed-off-by: Tony Lindgren <tony@...mide.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/input/keyboard/omap4-keypad.c |   39 ++++++++++++++++++++++-----------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
index 6dcf27af856d..c48705dd049b 100644
--- a/drivers/input/keyboard/omap4-keypad.c
+++ b/drivers/input/keyboard/omap4-keypad.c
@@ -71,6 +71,7 @@ struct omap4_keypad {
 
 	void __iomem *base;
 	unsigned int irq;
+	struct mutex lock;		/* for key scan */
 
 	unsigned int rows;
 	unsigned int cols;
@@ -135,6 +136,28 @@ static int omap4_keypad_report_keys(struct omap4_keypad *keypad_data,
 	return events;
 }
 
+static void omap4_keypad_scan_keys(struct omap4_keypad *keypad_data, u64 keys)
+{
+	u64 changed;
+
+	mutex_lock(&keypad_data->lock);
+
+	changed = keys ^ keypad_data->keys;
+
+	/*
+	 * Report key up events separately and first. This matters in case we
+	 * lost key-up interrupt and just now catching up.
+	 */
+	omap4_keypad_report_keys(keypad_data, changed & ~keys, false);
+
+	/* Report key down events */
+	omap4_keypad_report_keys(keypad_data, changed & keys, true);
+
+	keypad_data->keys = keys;
+
+	mutex_unlock(&keypad_data->lock);
+}
+
 /* Interrupt handlers */
 static irqreturn_t omap4_keypad_irq_handler(int irq, void *dev_id)
 {
@@ -150,24 +173,13 @@ static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
 {
 	struct omap4_keypad *keypad_data = dev_id;
 	u32 low, high;
-	u64 keys, changed;
+	u64 keys;
 
 	low = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE31_0);
 	high = kbd_readl(keypad_data, OMAP4_KBD_FULLCODE63_32);
 	keys = low | (u64)high << 32;
 
-	changed = keys ^ keypad_data->keys;
-
-	/*
-	 * Report key up events separately and first. This matters in case we
-	 * lost key-up interrupt and just now catching up.
-	 */
-	omap4_keypad_report_keys(keypad_data, changed & ~keys, false);
-
-	/* Report key down events */
-	omap4_keypad_report_keys(keypad_data, changed & keys, true);
-
-	keypad_data->keys = keys;
+	omap4_keypad_scan_keys(keypad_data, keys);
 
 	/* clear pending interrupts */
 	kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
@@ -300,6 +312,7 @@ static int omap4_keypad_probe(struct platform_device *pdev)
 	}
 
 	keypad_data->irq = irq;
+	mutex_init(&keypad_data->lock);
 
 	error = omap4_keypad_parse_dt(dev, keypad_data);
 	if (error)