1 files changed, 14 insertions, 4 deletions

diff --git a/drivers/input/keyboard/omap4-keypad.c b/drivers/input/keyboard/omap4-keypad.c
index 46406345742b..a7dc286f406c 100644
--- a/drivers/input/keyboard/omap4-keypad.c
+++ b/drivers/input/keyboard/omap4-keypad.c
@@ -60,8 +60,18 @@
 
 /* OMAP4 values */
 #define OMAP4_VAL_IRQDISABLE            0x0
-#define OMAP4_VAL_DEBOUNCINGTIME        0x7
-#define OMAP4_VAL_PVT                   0x7
+
+/*
+ * Errata i689: If a key is released for a time shorter than debounce time,
+ * the keyboard will idle and never detect the key release. The workaround
+ * is to use at least a 12ms debounce time. See omap5432 TRM chapter
+ * "26.4.6.2 Keyboard Controller Timer" for more information.
+ */
+#define OMAP4_KEYPAD_PTV_DIV_128        0x6
+#define OMAP4_KEYPAD_DEBOUNCINGTIME_MS(dbms, ptv)     \
+        ((((dbms) * 1000) / ((1 << ((ptv) + 1)) * (1000000 / 32768))) - 1)
+#define OMAP4_VAL_DEBOUNCINGTIME_16MS                                   \
+        OMAP4_KEYPAD_DEBOUNCINGTIME_MS(16, OMAP4_KEYPAD_PTV_DIV_128)
 
 enum {
         KBD_REVISION_OMAP4 = 0,
@@ -181,9 +191,9 @@ static int omap4_keypad_open(struct input_dev *input)
 
         kbd_writel(keypad_data, OMAP4_KBD_CTRL,
                         OMAP4_DEF_CTRL_NOSOFTMODE |
-                        (OMAP4_VAL_PVT << OMAP4_DEF_CTRL_PTV_SHIFT));
+                        (OMAP4_KEYPAD_PTV_DIV_128 << OMAP4_DEF_CTRL_PTV_SHIFT));
         kbd_writel(keypad_data, OMAP4_KBD_DEBOUNCINGTIME,
-                        OMAP4_VAL_DEBOUNCINGTIME);
+                        OMAP4_VAL_DEBOUNCINGTIME_16MS);
         /* clear pending interrupts */
         kbd_write_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS,
                          kbd_read_irqreg(keypad_data, OMAP4_KBD_IRQSTATUS));