Re: [PATCH 15/15] V4L/DVB: input: Add support for EVIO[CS]GKEYCODEBIG

["David Härdeman" <david@hardeman.nu>]

On Thu, Apr 01, 2010 at 02:56:31PM -0300, Mauro Carvalho Chehab wrote:
> Several devices use a high number of bits for scancodes. One important
> group is the Remote Controllers. Some new protocols like RC-6 define a
> scancode space of 64 bits.
> 
> The current EVIO[CS]GKEYCODE ioctls allow replace the scancode/keycode
> translation tables, but it is limited to up to 32 bits for scancode.
> 
> Also, if userspace wants to clean the existing table, replacing it by
> a new one, it needs to run a loop calling the old ioctls, over the
> entire sparsed scancode userspace.
> 
> To solve those problems, this patch introduces two new ioctls:
> 	EVIOCGKEYCODEBIG - reads a scancode from the translation table;
> 	EVIOSGKEYCODEBIG - writes a scancode into the translation table.
...
> diff --git a/include/linux/input.h b/include/linux/input.h
> index 663208a..6445fc9 100644
> --- a/include/linux/input.h
> +++ b/include/linux/input.h
> @@ -34,7 +34,7 @@ struct input_event {
>   * Protocol version.
>   */
>  
> -#define EV_VERSION		0x010000
> +#define EV_VERSION		0x010001
>  
>  /*
>   * IOCTLs (0x00 - 0x7f)
> @@ -56,12 +56,22 @@ struct input_absinfo {
>  	__s32 resolution;
>  };
>  
> +struct keycode_table_entry {
> +	__u32 keycode;		/* e.g. KEY_A */
> +	__u32 index;            /* Index for the given scan/key table, on EVIOCGKEYCODEBIG */
> +	__u32 len;		/* Length of the scancode */
> +	__u32 reserved[2];	/* Reserved for future usage */
> +	char *scancode;		/* scancode, in machine-endian */
> +};

Wouldn't changing the scancode member from a pointer to a flexible array 
member (C99 feature, which I assume is ok since other C99 features are 
already in use in the kernel code) remove the need for any compat32 
code?

struct keycode_table_entry {
	__u32 keycode;
	__u32 index;
	__u32 len;
	__u32 reserved[2];
	char scancode[];
};

-- 
David Härdeman