[U-Boot] [PATCH] common:usb_kbd:Add key values of F1~F12

[Simon Glass]

Hi,

On 9 August 2017 at 04:33, Dr. Philipp Tomsich
<philipp.tomsich at theobroma-systems.com> wrote:
>
>> On 08 Aug 2017, at 03:27, Leo Wen <leo.wen at rock-chips.com> wrote:
>>
>> When you press the F1~F12 button from the USB keyboard, the reference Fn
>> key table(usb_kbd_fn_key[]),the key value(0xf0~0xfb) will be returned,
>> and you can use it to do more things.
>
> How does doing this code (in usb_kbd.c) relate to the translation matrices
> in drivers/input/input.c (which maps from a scancode—i.e. ’typical AT-101
> position’ column in the USB HUT document—to the internal character
> value in U-Boot)?

There is no relation unfortunately. The usb protocol uses a different
encoding I believe.

>
> And should we even expose the function keys via getc() instead of generating
> escape sequences? The key values 0xf0 through 0xfb are usually not associated
> with F1 through F12.

I think escape codes should be used, but I am not an expert on this.

>
> Note that with drivers/input/input.c, I would expect escapes to be generated
> for KEY_F1 (\033OP) through KEY_F12 (\033[24~)… which would need to
> be added to the kbd_to_ansi364 table.
>
>> Signed-off-by: Leo Wen <leo.wen at rock-chips.com>
>> ---
>> common/usb_kbd.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/common/usb_kbd.c b/common/usb_kbd.c
>> index d2d29cc..7c96c78 100644
>> --- a/common/usb_kbd.c
>> +++ b/common/usb_kbd.c
>> @@ -73,6 +73,10 @@ static const unsigned char usb_kbd_num_keypad[] = {
>>       '1', '2', '3', '4', '5', '6', '7', '8', '9', '0',
>>       '.', 0, 0, 0, '='
>> };
>> +static const unsigned char usb_kbd_fn_key[] = {
>> +     0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5,
>> +     0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb
>> +};
>
> Why did you choose these values to encode F1 through F12?
> Is there some precedent for using these character codes for these keys?
>
>>
>> /*
>>  * map arrow keys to ^F/^B ^N/^P, can't really use the proper
>> @@ -206,6 +210,9 @@ static int usb_kbd_translate(struct usb_kbd_pdata *data, unsigned char scancode,
>>               else
>>                       keycode = usb_kbd_numkey[scancode - 0x1e];
>>       }
>> +     /* Fn keys pressed */
>> +     if ((scancode >= 0x3a) && (scancode <= 0x45))
>> +             keycode = usb_kbd_fn_key[scancode - 0x3a];
>>
>>       /* Arrow keys */
>>       if ((scancode >= 0x4f) && (scancode <= 0x52))
>> --
>> 2.7.4
>>
>>

Regards,
Simon