Input: omap-keypad - fix idle configuration to not block SoC idle states

With PM enabled, I noticed that pressing a key on the droid4 keyboard will
block deeper idle states for the SoC. Let's fix this by using IRQF_ONESHOT
and stop constantly toggling the device OMAP4_KBD_IRQENABLE register as
suggested by Dmitry Torokhov <dmitry.torokhov@gmail.com>.

From the hardware point of view, looks like we need to manage the registers
for OMAP4_KBD_IRQENABLE and OMAP4_KBD_WAKEUPENABLE together to avoid
blocking deeper SoC idle states. And with toggling of OMAP4_KBD_IRQENABLE
register now gone with IRQF_ONESHOT, also the SoC idle state problem is
gone during runtime. We still also need to clear OMAP4_KBD_WAKEUPENABLE in
omap4_keypad_close() though to pair it with omap4_keypad_open() to prevent
blocking deeper SoC idle states after rmmod omap4-keypad.

Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 4 insertions, 12 deletions

diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
index ce8e2baf31bb..616fdd94b069 100644
--- a/drivers/input/keyboard/omap4-keypad.c
+++ b/drivers/input/keyboard/omap4-keypad.c
@@ -126,12 +126,8 @@ static irqreturn_t omap4_keypad_irq_handler(int irq, void *dev_id)
 {
         struct omap4_keypad *keypad_data = dev_id;
 
-        if (kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS)) {
-                /* Disable interrupts */
-                kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
-                                 OMAP4_VAL_IRQDISABLE);
+        if (kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS))
                 return IRQ_WAKE_THREAD;
-        }
 
         return IRQ_NONE;
 }
@@ -173,11 +169,6 @@ static irqreturn_t omap4_keypad_irq_thread_fn(int irq, void *dev_id)
         kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
                          kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));
 
-        /* enable interrupts */
-        kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
-                OMAP4_DEF_IRQENABLE_EVENTEN |
-                                OMAP4_DEF_IRQENABLE_LONGKEY);
-
         return IRQ_HANDLED;
 }
 
@@ -214,9 +205,10 @@ static void omap4_keypad_close(struct input_dev *input)
 
         disable_irq(keypad_data->irq);
 
-        /* Disable interrupts */
+        /* Disable interrupts and wake-up events */
         kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQENABLE,
                          OMAP4_VAL_IRQDISABLE);
+        kbd_writel(keypad_data, OMAP4_KBD_WAKEUPENABLE, 0);
 
         /* clear pending interrupts */
         kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
@@ -364,7 +356,7 @@ static int omap4_keypad_probe(struct platform_device *pdev)
         }
 
         error = request_threaded_irq(keypad_data->irq, omap4_keypad_irq_handler,
-                                     omap4_keypad_irq_thread_fn, 0,
+                                     omap4_keypad_irq_thread_fn, IRQF_ONESHOT,
                                      "omap4-keypad", keypad_data);
         if (error) {
                 dev_err(&pdev->dev, "failed to register interrupt\n");