Re: [PATCH v2 2/3] dell-wmi: Support new hotkeys on the XPS 13 9350 (Skylake)

[Mario Limonciello <mario_limonciello@dell.com>]

On 11/30/2015 07:02 PM, Andy Lutomirski wrote:
> The XPS 13 9350 sends WMI keypress events that aren't enumerated in
> the DMI table.  Add a table listing them.  To avoid breaking things
> that worked before, these un-enumerated hotkeys won't be used if the
> DMI table maps them to something else.
>
> FWIW, it appears that the DMI table may be a legacy thing and we
> might want to rethink how we handle events in general.  As an
> example, a whole lot of things map to KEY_PROG3 via the DMI table.
>
> So far, this doesn't send keypress events for any of the new
> events.  Depnding on whether we figure out exactly what needs to
> happen to get the wireless button working in time for Linux 4.5,
> we might want to temporarily handle it in dell-wmi.
>
> Signed-off-by: Andy Lutomirski <luto@kernel.org>
> ---
>  drivers/platform/x86/dell-wmi.c | 59 ++++++++++++++++++++++++++++++++++++-----
>  1 file changed, 52 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/platform/x86/dell-wmi.c b/drivers/platform/x86/dell-wmi.c
> index ad6e965c5862..baff658a3621 100644
> --- a/drivers/platform/x86/dell-wmi.c
> +++ b/drivers/platform/x86/dell-wmi.c
> @@ -161,6 +161,27 @@ static const u16 bios_to_linux_keycode[256] __initconst = {
>  	[255]	= KEY_PROG3,
>  };
>  
> +/* These are applied if the hk table is present and doesn't override them. */
> +static const struct key_entry dell_wmi_extra_keymap[] __initconst = {
> +	/* Fn-lock */
> +	{ KE_IGNORE, 0x151, { KEY_RESERVED } },
> +
> +	/* Change keyboard illumination */
> +	{ KE_IGNORE, 0x152, { KEY_KBDILLUMTOGGLE } },
> +
> +	/*
> +	 * Radio disable (notify only -- there is no model for which the
> +	 * WMI event is supposed to trigger an action.
> +	 */
> +	{ KE_IGNORE, 0x153, { KEY_RFKILL } },
> +
> +	/* RGB keyboard backlight control */
> +	{ KE_IGNORE, 0x154, { KEY_RESERVED } },
> +
> +	/* Stealth mode toggle */
> +	{ KE_IGNORE, 0x155, { KEY_RESERVED } },
> +};
> +
>  static struct input_dev *dell_wmi_input_dev;
>  
>  static void dell_wmi_process_key(int reported_key)
> @@ -319,9 +340,10 @@ static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
>  	int hotkey_num = (dell_bios_hotkey_table->header.length - 4) /
>  				sizeof(struct dell_bios_keymap_entry);
>  	struct key_entry *keymap;
> -	int i;
> +	int i, pos = 0, num_bios_keys;
>  
> -	keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL);
> +	keymap = kcalloc(hotkey_num + ARRAY_SIZE(dell_wmi_extra_keymap),
> +			 sizeof(struct key_entry), GFP_KERNEL);
>  	if (!keymap)
>  		return NULL;
>  
> @@ -333,14 +355,37 @@ static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
>  				    KEY_RESERVED;
>  
>  		if (keycode == KEY_KBDILLUMTOGGLE)
> -			keymap[i].type = KE_IGNORE;
> +			keymap[pos].type = KE_IGNORE;
>  		else
> -			keymap[i].type = KE_KEY;
> -		keymap[i].code = bios_entry->scancode;
> -		keymap[i].keycode = keycode;
> +			keymap[pos].type = KE_KEY;
> +		keymap[pos].code = bios_entry->scancode;
> +		keymap[pos].keycode = keycode;
> +
> +		pos++;
> +	}
> +
> +	num_bios_keys = pos;
> +
> +	for (i = 0; i < ARRAY_SIZE(dell_wmi_extra_keymap); i++) {
> +		int j;
> +
> +		/*
> +		 * Check if we've already found this scancode.  This takes
> +		 * quadratic time, but it doesn't matter unless the list
> +		 * of extra keys gets very long.
> +		 */
> +		for (j = 0; j < num_bios_keys; j++)
> +			if (keymap[j].code == dell_wmi_extra_keymap[i].code)
> +				goto skip;
> +
> +		keymap[pos] = dell_wmi_extra_keymap[i];
> +		pos++;
> +
> +skip:
> +		;
>  	}
>  
> -	keymap[hotkey_num].type = KE_END;
> +	keymap[pos].type = KE_END;
>  
>  	return keymap;
>  }
I agree, if you don't come up with a solution for using INT33D5 for 4.5,
you may as well repurpose the WMI notification temporarily.