From: Tony Lindgren tony@atomide.com
[ Upstream commit 6c3516fed7b61a3527459ccfa67fab130d910610 ]
I noticed that the Android v3.0.8 kernel on droid4 is using different keypad values from the mainline kernel and does not have issues with keys occasionally being stuck until pressed again. Turns out there was an earlier patch posted to fix this as "Input: omap-keypad: errata i689: Correct debounce time", but it was never reposted to fix use macros for timing calculations.
This updated version is using macros, and also fixes the use of the input clock rate to use 32768KiHz instead of 32000KiHz. And we want to use the known good Android kernel values of 3 and 6 instead of 2 and 6 in the earlier patch.
Reported-by: Pavel Machek pavel@ucw.cz Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/input/keyboard/omap4-keypad.c | 18 ++++++++++++++---- 1 file 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));