[U-Boot,v6,1/3] PXA: PXA27x Matrix keypad driver

From: Marek Vasut <marek.vasut@gmail.com>

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
[vasily: adapted Marek's old version for newer u-boot,
         fixed multiple keypresses handling]
---
v2: use struct-based access to regs, minor cleanup
v3: fix multiple keypresses handling, minor cleanup
v4: another minor cleanup
v5: fix indentation issues in scan_keys(), remove udelay,
    increase PXA_KEYPAD_TIMEOUT (due to removed udelay)
v6: remove ifdefs around WATCHDOG_RESET()

 arch/arm/include/asm/arch-pxa/pxa-regs.h    |   52 -----
 arch/arm/include/asm/arch-pxa/regs-keypad.h |   84 ++++++++
 drivers/input/Makefile                      |    2 +
 drivers/input/pxa27x-mkp.c                  |  289 +++++++++++++++++++++++++++
 4 files changed, 375 insertions(+), 52 deletions(-)
 create mode 100644 arch/arm/include/asm/arch-pxa/regs-keypad.h
 create mode 100644 drivers/input/pxa27x-mkp.c

> From: Marek Vasut <marek.vasut@gmail.com>
> 
> Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> [vasily: adapted Marek's old version for newer u-boot,
>          fixed multiple keypresses handling]

Fine ... albert, can you comment on it?

Vasily, do you think this code is good? I want an honest answer!

> ---
> v2: use struct-based access to regs, minor cleanup
> v3: fix multiple keypresses handling, minor cleanup
> v4: another minor cleanup
> v5: fix indentation issues in scan_keys(), remove udelay,
>     increase PXA_KEYPAD_TIMEOUT (due to removed udelay)
> v6: remove ifdefs around WATCHDOG_RESET()
> 
>  arch/arm/include/asm/arch-pxa/pxa-regs.h    |   52 -----
>  arch/arm/include/asm/arch-pxa/regs-keypad.h |   84 ++++++++
>  drivers/input/Makefile                      |    2 +
>  drivers/input/pxa27x-mkp.c                  |  289
> +++++++++++++++++++++++++++ 4 files changed, 375 insertions(+), 52
> deletions(-)
>  create mode 100644 arch/arm/include/asm/arch-pxa/regs-keypad.h
>  create mode 100644 drivers/input/pxa27x-mkp.c
> 
> diff --git a/arch/arm/include/asm/arch-pxa/pxa-regs.h
> b/arch/arm/include/asm/arch-pxa/pxa-regs.h index b81b42c..d562658 100644
> --- a/arch/arm/include/asm/arch-pxa/pxa-regs.h
> +++ b/arch/arm/include/asm/arch-pxa/pxa-regs.h
> @@ -2567,58 +2567,6 @@ typedef void		(*ExcpHndlr) (void) ;
>  #define OVL2C1_O2EN	(1<<31)		/* Enable bit for Overlay 2 */
>  #define CCR_CEN		(1<<31)		/* Enable bit for Cursor */
> 
> -/* Keypad controller */
> -
> -#define KPC		0x41500000 /* Keypad Interface Control register */
> -#define KPDK		0x41500008 /* Keypad Interface Direct Key register */
> -#define KPREC		0x41500010 /* Keypad Intefcace Rotary Encoder 
register */
> -#define KPMK		0x41500018 /* Keypad Intefcace Matrix Key register */
> -#define KPAS		0x41500020 /* Keypad Interface Automatic Scan register 
*/
> -#define KPASMKP0	0x41500028 /* Keypad Interface Automatic Scan Multiple
> Key Presser register 0 */ -#define KPASMKP1	0x41500030 /* Keypad Interface
> Automatic Scan Multiple Key Presser register 1 */ -#define
> KPASMKP2	0x41500038 /* Keypad Interface Automatic Scan Multiple Key
> Presser register 2 */ -#define KPASMKP3	0x41500040 /* Keypad Interface
> Automatic Scan Multiple Key Presser register 3 */ -#define
> KPKDI		0x41500048 /* Keypad Interface Key Debounce Interval register */ 
-
> -#define KPC_AS		(0x1 << 30)  /* Automatic Scan bit */
> -#define KPC_ASACT	(0x1 << 29)  /* Automatic Scan on Activity */
> -#define KPC_MI		(0x1 << 22)  /* Matrix interrupt bit */
> -#define KPC_IMKP	(0x1 << 21)  /* Ignore Multiple Key Press */
> -#define KPC_MS7		(0x1 << 20)  /* Matrix scan line 7 */
> -#define KPC_MS6		(0x1 << 19)  /* Matrix scan line 6 */
> -#define KPC_MS5		(0x1 << 18)  /* Matrix scan line 5 */
> -#define KPC_MS4		(0x1 << 17)  /* Matrix scan line 4 */
> -#define KPC_MS3		(0x1 << 16)  /* Matrix scan line 3 */
> -#define KPC_MS2		(0x1 << 15)  /* Matrix scan line 2 */
> -#define KPC_MS1		(0x1 << 14)  /* Matrix scan line 1 */
> -#define KPC_MS0		(0x1 << 13)  /* Matrix scan line 0 */
> -#define KPC_ME		(0x1 << 12)  /* Matrix Keypad Enable */
> -#define KPC_MIE		(0x1 << 11)  /* Matrix Interrupt Enable */
> -#define KPC_DK_DEB_SEL	(0x1 <<	 9)  /* Direct Key Debounce select */
> -#define KPC_DI		(0x1 <<	 5)  /* Direct key interrupt bit */
> -#define KPC_DEE0	(0x1 <<	 2)  /* Rotary Encoder 0 Enable */
> -#define KPC_DE		(0x1 <<	 1)  /* Direct Keypad Enable */
> -#define KPC_DIE		(0x1 <<	 0)  /* Direct Keypad interrupt Enable 
*/
> -
> -#define KPDK_DKP	(0x1 << 31)
> -#define KPDK_DK7	(0x1 <<	 7)
> -#define KPDK_DK6	(0x1 <<	 6)
> -#define KPDK_DK5	(0x1 <<	 5)
> -#define KPDK_DK4	(0x1 <<	 4)
> -#define KPDK_DK3	(0x1 <<	 3)
> -#define KPDK_DK2	(0x1 <<	 2)
> -#define KPDK_DK1	(0x1 <<	 1)
> -#define KPDK_DK0	(0x1 <<	 0)
> -
> -#define KPREC_OF1	(0x1 << 31)
> -#define kPREC_UF1	(0x1 << 30)
> -#define KPREC_OF0	(0x1 << 15)
> -#define KPREC_UF0	(0x1 << 14)
> -
> -#define KPMK_MKP	(0x1 << 31)
> -#define KPAS_SO		(0x1 << 31)
> -#define KPASMKPx_SO	(0x1 << 31)
> -
>  #define GPIO113_BIT	(1 << 17)/* GPIO113 in GPSR, GPCR, bit 17 */
>  #define PSLR		0x40F00034
>  #define PSTR		0x40F00038  /* Power Manager Standby Configuration Reg 
*/
> diff --git a/arch/arm/include/asm/arch-pxa/regs-keypad.h
> b/arch/arm/include/asm/arch-pxa/regs-keypad.h new file mode 100644
> index 0000000..1909417
> --- /dev/null
> +++ b/arch/arm/include/asm/arch-pxa/regs-keypad.h
> @@ -0,0 +1,84 @@
> +/*
> + * Copyright (C) 2012 Vasily Khoruzhick <anarsoul@gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#ifndef __REGS_KEYPAD_H__
> +#define __REGS_KEYPAD_H__
> +
> +#define KEYPAD_BASE	0x41500000
> +
> +struct kpasmkp_regs {
> +	uint32_t	kpasmkpx;
> +	uint32_t	reserved;
> +};
> +
> +struct pxa_keypad_regs {
> +	uint32_t		kpc;
> +	uint32_t		reserved_1;
> +	uint32_t		kpdk;
> +	uint32_t		reserved_2;
> +	uint32_t		kprec;
> +	uint32_t		reserved_3;
> +	uint32_t		kpmk;
> +	uint32_t		reserved_4;
> +	uint32_t		kpas;
> +	uint32_t		reserved_5;
> +	struct kpasmkp_regs	kpasmkp[4];
> +	uint32_t		kpkdi;
> +};
> +
> +#define KPC_AS		(0x1 << 30)	/* Automatic Scan bit */
> +#define KPC_ASACT	(0x1 << 29)	/* Automatic Scan on Activity */
> +#define KPC_MI		(0x1 << 22)	/* Matrix interrupt bit */
> +#define KPC_IMKP	(0x1 << 21)	/* Ignore Multiple Key Press */
> +#define KPC_MS7		(0x1 << 20)	/* Matrix scan line 7 */
> +#define KPC_MS6		(0x1 << 19)	/* Matrix scan line 6 */
> +#define KPC_MS5		(0x1 << 18)	/* Matrix scan line 5 */
> +#define KPC_MS4		(0x1 << 17)	/* Matrix scan line 4 */
> +#define KPC_MS3		(0x1 << 16)	/* Matrix scan line 3 */
> +#define KPC_MS2		(0x1 << 15)	/* Matrix scan line 2 */
> +#define KPC_MS1		(0x1 << 14)	/* Matrix scan line 1 */
> +#define KPC_MS0		(0x1 << 13)	/* Matrix scan line 0 */
> +#define KPC_ME		(0x1 << 12)	/* Matrix Keypad Enable */
> +#define KPC_MIE		(0x1 << 11)	/* Matrix Interrupt Enable */
> +#define KPC_DK_DEB_SEL	(0x1 << 9)	/* Direct Key Debounce select */
> +#define KPC_DI		(0x1 << 5)	/* Direct key interrupt bit */
> +#define KPC_DEE0	(0x1 << 2)	/* Rotary Encoder 0 Enable */
> +#define KPC_DE		(0x1 << 1)	/* Direct Keypad Enable */
> +#define KPC_DIE		(0x1 << 0)	/* Direct Keypad interrupt 
Enable */
> +
> +#define KPDK_DKP	(0x1 << 31)
> +#define KPDK_DK7	(0x1 << 7)
> +#define KPDK_DK6	(0x1 << 6)
> +#define KPDK_DK5	(0x1 << 5)
> +#define KPDK_DK4	(0x1 << 4)
> +#define KPDK_DK3	(0x1 << 3)
> +#define KPDK_DK2	(0x1 << 2)
> +#define KPDK_DK1	(0x1 << 1)
> +#define KPDK_DK0	(0x1 << 0)
> +
> +#define KPREC_OF1	(0x1 << 31)
> +#define kPREC_UF1	(0x1 << 30)
> +#define KPREC_OF0	(0x1 << 15)
> +#define KPREC_UF0	(0x1 << 14)
> +
> +#define KPMK_MKP	(0x1 << 31)
> +#define KPAS_SO		(0x1 << 31)
> +#define KPASMKPx_SO	(0x1 << 31)
> +
> +#endif
> diff --git a/drivers/input/Makefile b/drivers/input/Makefile
> index 1f4dad3..792d29d 100644
> --- a/drivers/input/Makefile
> +++ b/drivers/input/Makefile
> @@ -31,6 +31,8 @@ COBJS-y += keyboard.o pc_keyb.o
>  COBJS-$(CONFIG_PS2MULT) += ps2mult.o ps2ser.o
>  endif
> 
> +COBJS-$(CONFIG_PXA27X_MKP) += pxa27x-mkp.o
> +
>  COBJS	:= $(COBJS-y)
>  SRCS	:= $(COBJS:.o=.c)
>  OBJS	:= $(addprefix $(obj),$(COBJS))
> diff --git a/drivers/input/pxa27x-mkp.c b/drivers/input/pxa27x-mkp.c
> new file mode 100644
> index 0000000..00c5fc6
> --- /dev/null
> +++ b/drivers/input/pxa27x-mkp.c
> @@ -0,0 +1,289 @@
> +/*
> + * PXA27x matrix keypad controller driver
> + *
> + * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
> + * Copyright (C) 2012 Vasily Khoruzhick <anarsoul@gmail.com>
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <stdio_dev.h>
> +#include <watchdog.h>
> +#include <asm/arch/regs-keypad.h>
> +#include <asm/io.h>
> +
> +#define	DEVNAME		"pxa27x-mkp"
> +
> +struct {
> +	char	row;
> +	char	col;
> +	char	key;
> +	char	shift;
> +	char	alt;
> +	char	ctrl;
> +} keymap[] = {
> +	CONFIG_PXA27X_MKP_KEYMAP,
> +};
> +
> +static unsigned char queue[64] = {0};
> +static int queue_len;
> +static struct pxa_keypad_regs *regs = (struct pxa_keypad_regs
> *)KEYPAD_BASE; +
> +/* autorepeat stuff */
> +static int last_key_row = 0xff, last_key_col = 0xff;
> +static char key_counter;
> +
> +/* number of key scans before autorepeat kicks in */
> +#ifndef CONFIG_PXA27X_KEY_REPEAT_FIRST
> +#define	CONFIG_PXA27X_KEY_REPEAT_FIRST	12
> +#endif
> +#ifndef CONFIG_PXA27X_KEY_REPEAT_NEXT
> +#define	CONFIG_PXA27X_KEY_REPEAT_NEXT	2
> +#endif
> +
> +/* Number of cycles to wait */
> +#define PXA_KEYPAD_TIMEOUT	100000
> +
> +enum {
> +	MOD_NONE,
> +	MOD_SHIFT,
> +	MOD_ALT,
> +	MOD_CTRL,
> +};
> +
> +static int kbd_get_mdf(int row, int col)
> +{
> +	char mod_shift[2] = CONFIG_PXA27X_MKP_MOD_SHIFT;
> +	char mod_alt[2] = CONFIG_PXA27X_MKP_MOD_ALT;
> +	char mod_ctrl[2] = CONFIG_PXA27X_MKP_MOD_CTRL;
> +
> +	if (mod_shift[0] == row && mod_shift[1] == col)
> +		return MOD_SHIFT;
> +	if (mod_alt[0] == row && mod_alt[1] == col)
> +		return MOD_ALT;
> +	if (mod_ctrl[0] == row && mod_ctrl[1] == col)
> +		return MOD_CTRL;
> +	return MOD_NONE;
> +}
> +
> +static int kbd_lookup(int row, int col, int mod)
> +{
> +	int i = 0;
> +	char key = 0xff;
> +
> +	while (!(keymap[i].col == 0xff && keymap[i].row == 0xff)) {
> +		if (keymap[i].row != row || keymap[i].col != col) {
> +			i++;
> +			continue;
> +		}
> +		switch (mod) {
> +		case MOD_NONE:
> +			key = keymap[i].key;
> +			break;
> +		case MOD_SHIFT:
> +			key = keymap[i].shift;
> +			break;
> +		case MOD_ALT:
> +			key = keymap[i].alt;
> +			break;
> +		case MOD_CTRL:
> +			key = keymap[i].ctrl;
> +			break;
> +		}
> +		if (key == 0xff) {
> +			i++;
> +			continue;
> +		}
> +
> +		if (row != last_key_row || col != last_key_col) {
> +			queue[queue_len++] = key;
> +			last_key_row = row;
> +			last_key_col = col;
> +			key_counter = 0;
> +		} else /* same key as before */
> +			if (key_counter < CONFIG_PXA27X_KEY_REPEAT_FIRST) {
> +				/* ignore key press */
> +				key_counter++;
> +			} else {
> +				/* ok, autorepeat */
> +				queue[queue_len++] = key;
> +				key_counter = CONFIG_PXA27X_KEY_REPEAT_FIRST
> +					- CONFIG_PXA27X_KEY_REPEAT_NEXT;
> +			}
> +		i++;
> +	}
> +	return key;
> +}
> +
> +static int scan_keys(int scan_modif, uint32_t kpasmkp[4])
> +{
> +	uint32_t reg = 0;
> +	int col, row;
> +	static int mod = MOD_NONE;
> +	int key;
> +	for (col = 0; col < 8; col += 1) {
> +		reg = kpasmkp[col >> 1];
> +		reg >>= 16 * (col % 2);
> +		for (row = 0; row < 8; row++) {
> +			if (!(reg & (1 << row)))
> +				continue;
> +
> +			if (scan_modif) {
> +				mod = kbd_get_mdf(row, col);
> +				if (mod != MOD_NONE)
> +					return mod;
> +			} else {
> +				key = kbd_lookup(row, col, mod);
> +				if (key != 0xff)
> +					return key;
> +			}
> +		}
> +	}
> +
> +	if (scan_modif)
> +		return MOD_NONE;
> +	else
> +		return 0xff;
> +}
> +
> +static void kbd_read(void)
> +{
> +	uint32_t reg;
> +	int col, row, i, have_new_key = 0;
> +	int numkeys;
> +	int mod = MOD_NONE;
> +	unsigned int timeout = PXA_KEYPAD_TIMEOUT;
> +	static uint32_t kpasmkp_old[4];
> +	uint32_t kpasmkp[4], kpasmkp_diff[4];
> +
> +	/* start one automatic scan */
> +	writel(readl(&regs->kpc) | KPC_AS, &regs->kpc);
> +
> +	/* wait for scan to finish */
> +	while (timeout--) {
> +		if (!(readl(&regs->kpc) & KPC_AS))
> +			break;
> +		WATCHDOG_RESET();
> +	}
> +
> +	if (!timeout)
> +		return;
> +
> +	numkeys = (readl(&regs->kpas) >> 26) & 0x1f;
> +	switch (numkeys) {
> +	case 0:
> +		/* no key pressed, clear autorepeat counter */
> +		key_counter = 0;
> +		last_key_row = last_key_col = 0xff;
> +		for (i = 0; i < ARRAY_SIZE(kpasmkp); i++)
> +			kpasmkp[i] = 0;
> +		break;
> +	case 1:
> +		reg = readl(&regs->kpas) & 0xff;
> +		col = reg & 0x0f;
> +		row = reg >> 4;
> +		for (i = 0; i < ARRAY_SIZE(kpasmkp); i++)
> +			kpasmkp[i] = 0;
> +		kpasmkp[col >> 1] |= (1 << (row + 16 * (col % 2)));
> +
> +		break;
> +	default:
> +		for (i = 0; i < ARRAY_SIZE(kpasmkp); i++) {
> +			timeout = PXA_KEYPAD_TIMEOUT;
> +			while (timeout--) {
> +				kpasmkp[i] = readl(&regs->kpasmkp[i].kpasmkpx);
> +				if (!(kpasmkp[i] & KPASMKPx_SO))
> +					break;
> +				WATCHDOG_RESET();
> +			}
> +			if (!timeout)
> +				kpasmkp[i] = 0;
> +		}
> +		break;
> +	}
> +
> +	/* Find new keypress */
> +	for (i = 0; i < ARRAY_SIZE(kpasmkp); i++) {
> +		kpasmkp_diff[i] = (kpasmkp_old[i] ^ kpasmkp[i]) &
> +			kpasmkp[i];
> +		if (kpasmkp_diff[i])
> +			have_new_key = 1;
> +		kpasmkp_old[i] = kpasmkp[i];
> +	}
> +
> +	if (!numkeys)
> +		return;
> +
> +	/* Scan for modifiers */
> +	mod = scan_keys(1, kpasmkp);
> +	if (!have_new_key) {
> +		/* Check if old key is still pressed */
> +		if (kpasmkp[last_key_col >> 1] &
> +		   (1 << (last_key_row + 16 * (last_key_col % 2))))
> +			kbd_lookup(last_key_row, last_key_col, mod);
> +
> +	} else {
> +		key_counter = 0;
> +		last_key_row = last_key_col = 0xff;
> +		scan_keys(0, kpasmkp_diff);
> +	}
> +}
> +
> +static int kbd_getc(void)
> +{
> +	if (!queue_len) {
> +		kbd_read();
> +		udelay(CONFIG_PXA27X_MKP_DELAY);
> +	}
> +
> +	if (queue_len)
> +		return queue[--queue_len];
> +	else
> +		return 0;
> +}
> +
> +static int kbd_testc(void)
> +{
> +	if (!queue_len)
> +		kbd_read();
> +	return queue_len;
> +}
> +
> +int drv_keyboard_init(void)
> +{
> +	int error = 0;
> +	struct stdio_dev kbddev;
> +
> +	writel((CONFIG_PXA27X_MKP_MKP_ROWS << 26) |
> +		(CONFIG_PXA27X_MKP_MKP_COLS << 23) |
> +		(0xff << 13) | KPC_ME, &regs->kpc);
> +	writel(CONFIG_PXA27X_MKP_DEBOUNCE, &regs->kpkdi);
> +
> +	memset(&kbddev, 0, sizeof(kbddev));
> +	strcpy(kbddev.name, DEVNAME);
> +	kbddev.flags =  DEV_FLAGS_INPUT | DEV_FLAGS_SYSTEM;
> +	kbddev.putc = NULL;
> +	kbddev.puts = NULL;
> +	kbddev.getc = kbd_getc;
> +	kbddev.tstc = kbd_testc;
> +
> +	error = stdio_register(&kbddev);
> +	return error;
> +}

2012/1/25 Marek Vasut <marek.vasut@gmail.com>:
>> From: Marek Vasut <marek.vasut@gmail.com>
>>
>> Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
>> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
>> [vasily: adapted Marek's old version for newer u-boot,
>>          fixed multiple keypresses handling]
>
> Fine ... albert, can you comment on it?
>
> Vasily, do you think this code is good? I want an honest answer!

Well, it's overcomplicated due to missing _generic_ keyboard support in u-boot.
It's possible to separate buffer handling, layout management into some
"keyboard-core",
so keyboard driver provides only key press/release events to core and
then core decides
what to do if we have multiple keys pressed, if modifier is pressed, etc, etc...

Anyway, for me this code is easy to understand, but it's for now. So
if you want _really_ honest answer -- wait for few weeks
so I can re-review it with fresh view.

Regards
Vasily

> 2012/1/25 Marek Vasut <marek.vasut@gmail.com>:
> >> From: Marek Vasut <marek.vasut@gmail.com>
> >> 
> >> Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
> >> Signed-off-by: Vasily Khoruzhick <anarsoul@gmail.com>
> >> [vasily: adapted Marek's old version for newer u-boot,
> >>          fixed multiple keypresses handling]
> > 
> > Fine ... albert, can you comment on it?
> > 
> > Vasily, do you think this code is good? I want an honest answer!
> 
> Well, it's overcomplicated due to missing _generic_ keyboard support in
> u-boot.

Then create such code!

> It's possible to separate buffer handling, layout management into
> some "keyboard-core",
> so keyboard driver provides only key press/release events to core and
> then core decides
> what to do if we have multiple keys pressed, if modifier is pressed, etc,
> etc...

Great idea, let's put this patch on hold and implement the support layer then!
> 
> Anyway, for me this code is easy to understand, but it's for now. So
> if you want _really_ honest answer -- wait for few weeks
> so I can re-review it with fresh view.

I don't mind. But maybe you can really implement the keyboard support layer and 
simply add this as a clean and easy driver.

M
> 
> Regards
> Vasily