From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: [PATCH 1/2] Input: omap-keypad: Fix keyboard debounce configuration Date: Sun, 2 Dec 2018 17:29:32 -0800 Message-ID: <20181203012933.6647-1-tony@atomide.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, Axel Haslam , Felipe Balbi , Illia Smyrnov , Marcel Partap , Merlijn Wajer , Michael Scott , NeKit , Pavel Machek , Sebastian Reichel List-Id: linux-input@vger.kernel.org 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. Cc: Axel Haslam Cc: Felipe Balbi Cc: Illia Smyrnov Cc: Marcel Partap Cc: Merlijn Wajer Cc: Michael Scott Cc: NeKit Cc: Pavel Machek Cc: Sebastian Reichel Reported-by: Pavel Machek Signed-off-by: Tony Lindgren --- 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 --- 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)); -- 2.19.2