Re: [RFC] Input - synaptics: re-route tracksticks buttons on the Lenovo 2015 series

[Andrew Duggan <aduggan@synaptics.com>]

On 02/05/2015 12:38 PM, Benjamin Tissoires wrote:
> Lenovos 2015 series has the physical tracktick buttons wired
> through the touchpad. The kernel should re-route them through
> the pass-through interface.
>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
>
> Hi Dmitry,
>
> Well, in one of your replies regarding the Synaptics Lenovo 2015
> series, you mentioned that you wouldn't mind having the trackstick
> buttons re-routed through the trackstick (pass-through interface).
>
> I came out with this patch (checkpatch complains a lot about it but
> today's setup is not that convenient), and I'd like to hear what you
> think of it.
>
> If you agree to go this path, I'll remove the warnings from checkpatch
> and do a proper submission.
>
> The patch is still not future proof (if Synaptics updates the board like
> they did for the *40 series, we will need to fix this all over again),
> so I might have a little bit more of work to do. Anyway, it works.

I discovered that there is a firmware query to determine if the touchpad 
has stick buttons which are wired to the touchpad and are reported as 
extended buttons. Query $01 bit 17 indicates that Query $10 exists. Then 
Query $10 bit 0 indicates indicates the extended buttons should be 
mapped to the guest stick buttons.

Additional information and some diagrams are in the pdf here:
https://www.dropbox.com/s/vv1j4zsytgrw7mm/synaptics-tp-stick-buttons.pdf?dl=0

> Cheers,
> Benjamin
>
>   drivers/input/mouse/synaptics.c | 55 ++++++++++++++++++++++++++++++++---------
>   drivers/input/mouse/synaptics.h |  2 ++
>   2 files changed, 46 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
> index fc0099c..e32cac1 100644
> --- a/drivers/input/mouse/synaptics.c
> +++ b/drivers/input/mouse/synaptics.c
> @@ -190,6 +190,11 @@ static const char * const topbuttonpad_pnp_ids[] = {
>   	NULL
>   };
>   
> +static const char * const trackstick_buttons_pnp_ids[] = {
> +	"LEN0048",
> +	NULL
> +};
> +
>   /*****************************************************************************
>    *	Synaptics communications functions
>    ****************************************************************************/
> @@ -512,18 +517,20 @@ static int synaptics_is_pt_packet(unsigned char *buf)
>   	return (buf[0] & 0xFC) == 0x84 && (buf[3] & 0xCC) == 0xC4;
>   }
>   
> -static void synaptics_pass_pt_packet(struct serio *ptport, unsigned char *packet)
> +static void synaptics_pass_pt_packet(struct psmouse *psmouse, struct serio *ptport,
> +		unsigned char *packet)
>   {
> +	struct synaptics_data *priv = psmouse->private;
>   	struct psmouse *child = serio_get_drvdata(ptport);
>   
>   	if (child && child->state == PSMOUSE_ACTIVATED) {
> -		serio_interrupt(ptport, packet[1], 0);
> +		serio_interrupt(ptport, packet[1] | priv->pt_buttons, 0);
>   		serio_interrupt(ptport, packet[4], 0);
>   		serio_interrupt(ptport, packet[5], 0);
>   		if (child->pktsize == 4)
>   			serio_interrupt(ptport, packet[2], 0);
>   	} else
> -		serio_interrupt(ptport, packet[1], 0);
> +		serio_interrupt(ptport, packet[1] | priv->pt_buttons, 0);
>   }
>   
>   static void synaptics_pt_activate(struct psmouse *psmouse)
> @@ -782,11 +789,33 @@ static void synaptics_report_buttons(struct psmouse *psmouse,
>   		input_report_key(dev, BTN_BACK, hw->down);
>   	}
>   
> -	for (i = 0; i < ext_bits; i++) {
> -		input_report_key(dev, BTN_0 + 2 * i,
> -				 hw->ext_buttons & (1 << i));
> -		input_report_key(dev, BTN_1 + 2 * i,
> -				 hw->ext_buttons & (1 << (i + ext_bits)));
> +	if (!priv->override_pt_buttons) {
> +		for (i = 0; i < ext_bits; i++) {
> +			input_report_key(dev, BTN_0 + 2 * i,
> +					 hw->ext_buttons & (1 << i));
> +			input_report_key(dev, BTN_1 + 2 * i,
> +					 hw->ext_buttons & (1 << (i + ext_bits)));
> +		}
> +	} else {
> +		/*
> +		 * This generation of touchpads has the trackstick buttons
> +		 * physically wired to the touchpad. Re-route them through
> +		 * the pass-through interface.
> +		 */
> +		if (priv->pt_port &&
> +		    SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) &&
> +		    ((psmouse->packet[0] ^ psmouse->packet[3]) & 0x02)) {
> +			char buf[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
> +			priv->pt_buttons = 0x00;
> +			/* ext_bits is guaranteed to be <= 4 */
> +			for (i = 0; i < ext_bits; i++) {
> +				if (hw->ext_buttons & (1 << i))
> +					priv->pt_buttons |= 1 << (2 * i);
> +				if (hw->ext_buttons & (1 << (i + ext_bits)))
> +					priv->pt_buttons |= 1 << (2 * i + 1);
> +			}
> +			synaptics_pass_pt_packet(psmouse, priv->pt_port, buf);
> +		}
>   	}
>   }
>   
> @@ -1008,7 +1037,8 @@ static psmouse_ret_t synaptics_process_byte(struct psmouse *psmouse)
>   		if (SYN_CAP_PASS_THROUGH(priv->capabilities) &&
>   		    synaptics_is_pt_packet(psmouse->packet)) {
>   			if (priv->pt_port)
> -				synaptics_pass_pt_packet(priv->pt_port, psmouse->packet);
> +				synaptics_pass_pt_packet(psmouse, priv->pt_port,
> +							 psmouse->packet);
>   		} else
>   			synaptics_process_packet(psmouse);
>   
> @@ -1110,8 +1140,11 @@ static void set_input_params(struct psmouse *psmouse,
>   		__set_bit(BTN_BACK, dev->keybit);
>   	}
>   
> -	for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
> -		__set_bit(BTN_0 + i, dev->keybit);
> +	if (!psmouse_matches_pnp_id(psmouse, trackstick_buttons_pnp_ids))
> +		for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
> +			__set_bit(BTN_0 + i, dev->keybit);
> +	else
> +		priv->override_pt_buttons = true;
>   
>   	__clear_bit(EV_REL, dev->evbit);
>   	__clear_bit(REL_X, dev->relbit);
> diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
> index 6faf9bb..fc39b01 100644
> --- a/drivers/input/mouse/synaptics.h
> +++ b/drivers/input/mouse/synaptics.h
> @@ -156,6 +156,8 @@ struct synaptics_data {
>   	bool disable_gesture;			/* disable gestures */
>   
>   	struct serio *pt_port;			/* Pass-through serio port */
> +	unsigned char pt_buttons;		/* Pass-through overriding buttons */
> +	bool override_pt_buttons;		/* Override the pass-through buttons */
>   
>   	/*
>   	 * Last received Advanced Gesture Mode (AGM) packet. An AGM packet