Patch "Input: nspire-keypad - enable interrupts only when opened" has been added to the 4.4-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    Input: nspire-keypad - enable interrupts only when opened

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     input-nspire-keypad-enable-interrupts-only-when-open.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 343ccc6eb7b58bec7b9eb5a97a0aa9c5a01f6cbc
Author: Fabian Vogt <fabian@xxxxxxxxxxxxxx>
Date:   Tue Mar 23 10:45:55 2021 -0700

    Input: nspire-keypad - enable interrupts only when opened
    
    [ Upstream commit 69d5ff3e9e51e23d5d81bf48480aa5671be67a71 ]
    
    The driver registers an interrupt handler in _probe, but didn't configure
    them until later when the _open function is called. In between, the keypad
    can fire an IRQ due to touchpad activity, which the handler ignores. This
    causes the kernel to disable the interrupt, blocking the keypad from
    working.
    
    Fix this by disabling interrupts before registering the handler.
    Additionally, disable them in _close, so that they're only enabled while
    open.
    
    Fixes: fc4f31461892 ("Input: add TI-Nspire keypad support")
    Signed-off-by: Fabian Vogt <fabian@xxxxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/3383725.iizBOSrK1V@xxxxxxxxxxxxxxxxxx
    Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/input/keyboard/nspire-keypad.c b/drivers/input/keyboard/nspire-keypad.c
index 7abfd34eb87e..bcec72367c1d 100644
--- a/drivers/input/keyboard/nspire-keypad.c
+++ b/drivers/input/keyboard/nspire-keypad.c
@@ -96,9 +96,15 @@ static irqreturn_t nspire_keypad_irq(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
-static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
+static int nspire_keypad_open(struct input_dev *input)
 {
+	struct nspire_keypad *keypad = input_get_drvdata(input);
 	unsigned long val = 0, cycles_per_us, delay_cycles, row_delay_cycles;
+	int error;
+
+	error = clk_prepare_enable(keypad->clk);
+	if (error)
+		return error;
 
 	cycles_per_us = (clk_get_rate(keypad->clk) / 1000000);
 	if (cycles_per_us == 0)
@@ -124,30 +130,6 @@ static int nspire_keypad_chip_init(struct nspire_keypad *keypad)
 	keypad->int_mask = 1 << 1;
 	writel(keypad->int_mask, keypad->reg_base + KEYPAD_INTMSK);
 
-	/* Disable GPIO interrupts to prevent hanging on touchpad */
-	/* Possibly used to detect touchpad events */
-	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
-	/* Acknowledge existing interrupts */
-	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
-
-	return 0;
-}
-
-static int nspire_keypad_open(struct input_dev *input)
-{
-	struct nspire_keypad *keypad = input_get_drvdata(input);
-	int error;
-
-	error = clk_prepare_enable(keypad->clk);
-	if (error)
-		return error;
-
-	error = nspire_keypad_chip_init(keypad);
-	if (error) {
-		clk_disable_unprepare(keypad->clk);
-		return error;
-	}
-
 	return 0;
 }
 
@@ -155,6 +137,11 @@ static void nspire_keypad_close(struct input_dev *input)
 {
 	struct nspire_keypad *keypad = input_get_drvdata(input);
 
+	/* Disable interrupts */
+	writel(0, keypad->reg_base + KEYPAD_INTMSK);
+	/* Acknowledge existing interrupts */
+	writel(~0, keypad->reg_base + KEYPAD_INT);
+
 	clk_disable_unprepare(keypad->clk);
 }
 
@@ -215,6 +202,25 @@ static int nspire_keypad_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	error = clk_prepare_enable(keypad->clk);
+	if (error) {
+		dev_err(&pdev->dev, "failed to enable clock\n");
+		return error;
+	}
+
+	/* Disable interrupts */
+	writel(0, keypad->reg_base + KEYPAD_INTMSK);
+	/* Acknowledge existing interrupts */
+	writel(~0, keypad->reg_base + KEYPAD_INT);
+
+	/* Disable GPIO interrupts to prevent hanging on touchpad */
+	/* Possibly used to detect touchpad events */
+	writel(0, keypad->reg_base + KEYPAD_UNKNOWN_INT);
+	/* Acknowledge existing GPIO interrupts */
+	writel(~0, keypad->reg_base + KEYPAD_UNKNOWN_INT_STS);
+
+	clk_disable_unprepare(keypad->clk);
+
 	input_set_drvdata(input, keypad);
 
 	input->id.bustype = BUS_HOST;