Input: imx_keypad - add pm suspend and resume support

The imx_keypad driver was indicating that it was wakeup capable in
imx_keypad_probe(), but it didn't implement suspend or resume methods.

According to the i.MX series MCU Reference Manual, the kpp (keypad
port) is a major wake up source which can detect any key press even
in low power mode and even when there is no clock.

Signed-off-by: Hui Wang <jason77.wang@gmail.com>
Reviewed-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

1 files changed, 44 insertions, 0 deletions

diff --git a/drivers/input/keyboard/imx_keypad.c b/drivers/input/keyboard/imx_keypad.c
index 4b093faf5786..ccebd2d09151 100644
--- a/drivers/input/keyboard/imx_keypad.c
+++ b/drivers/input/keyboard/imx_keypad.c
@@ -567,10 +567,54 @@ static int __devexit imx_keypad_remove(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int imx_kbd_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct imx_keypad *kbd = platform_get_drvdata(pdev);
+        struct input_dev *input_dev = kbd->input_dev;
+
+        /* imx kbd can wake up system even clock is disabled */
+        mutex_lock(&input_dev->mutex);
+
+        if (input_dev->users)
+                clk_disable(kbd->clk);
+
+        mutex_unlock(&input_dev->mutex);
+
+        if (device_may_wakeup(&pdev->dev))
+                enable_irq_wake(kbd->irq);
+
+        return 0;
+}
+
+static int imx_kbd_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct imx_keypad *kbd = platform_get_drvdata(pdev);
+        struct input_dev *input_dev = kbd->input_dev;
+
+        if (device_may_wakeup(&pdev->dev))
+                disable_irq_wake(kbd->irq);
+
+        mutex_lock(&input_dev->mutex);
+
+        if (input_dev->users)
+                clk_enable(kbd->clk);
+
+        mutex_unlock(&input_dev->mutex);
+
+        return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(imx_kbd_pm_ops, imx_kbd_suspend, imx_kbd_resume);
+
 static struct platform_driver imx_keypad_driver = {
         .driver         = {
                 .name   = "imx-keypad",
                 .owner  = THIS_MODULE,
+                .pm     = &imx_kbd_pm_ops,
         },
         .probe          = imx_keypad_probe,
         .remove         = __devexit_p(imx_keypad_remove),