Re: [PATCH v2 6/7] Input: synaptics - re-route tracksticks buttons on the Lenovo 2015 series

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Fri, Feb 06, 2015 at 03:04:34PM -0500, Benjamin Tissoires wrote:
> The 2015 series of the Lenovo thinkpads added back the hardware buttons
> on top of the touchpad for the trackstick.
> 
> Unfortunately, they are wired to the touchpad, and not the trackstick.
> Thus, they are seen as extra buttons from the kernel point of view.
> 
> This leads to a problem in user space because extra buttons on synaptics
> devices used to be used as scroll up/down buttons. So in the end, the
> experience for the user is scroll events for buttons left and right
> when using the trackstick. Yay!
> 
> Fortunatelly, the firmware advertizes such behavior in the extended
> capability $10, and so we can re-route the buttons through the
> pass-through interface.
> 
> Hallelujah-expressed-by: Peter Hutterer <peter.hutterer@who-t.net>
> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
> ---
> 
> v2:
> - forward only 3 extra buttons, not the whole array. The PS/2 base protocol
>   handles only 3 buttons, so giving more than 3 will mess up REL_X and REL_Y.
> - rely on SYN_CAP_EXT_BUTTONS_STICK to know if the re-routing has to be put in
>   place or not
> 
>  drivers/input/mouse/synaptics.c | 45 +++++++++++++++++++++++++++++++----------
>  drivers/input/mouse/synaptics.h |  5 +++++
>  2 files changed, 39 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
> index 79c4a87..dfe8235 100644
> --- a/drivers/input/mouse/synaptics.c
> +++ b/drivers/input/mouse/synaptics.c
> @@ -585,18 +585,20 @@ 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);

We only need to pass the button state when trackpad is activated, not
when we are querying the device.

>  }
>  
>  static void synaptics_pt_activate(struct psmouse *psmouse)
> @@ -842,6 +844,7 @@ static void synaptics_report_ext_buttons(struct psmouse *psmouse,
>  	struct input_dev *dev = psmouse->dev;
>  	struct synaptics_data *priv = psmouse->private;
>  	int ext_bits = (SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap) + 1) >> 1;
> +	char buf[6] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
>  	int i;
>  
>  	if (!SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap))
> @@ -852,12 +855,30 @@ static void synaptics_report_ext_buttons(struct psmouse *psmouse,
>  	    !((psmouse->packet[0] ^ psmouse->packet[3]) & 0x02))
>  		return;
>  
> -	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 (!SYN_CAP_EXT_BUTTONS_STICK(priv->ext_cap_10)) {
> +		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)));
> +		}
> +		return;
>  	}
> +
> +	/*
> +	 * 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)
> +		return;
> +
> +	/* the trackstick expects at most 3 buttons */
> +	priv->pt_buttons = SYN_CAP_EXT_BUTTON_STICK_L(hw->ext_buttons)      |
> +			   SYN_CAP_EXT_BUTTON_STICK_R(hw->ext_buttons) << 1 |
> +			   SYN_CAP_EXT_BUTTON_STICK_M(hw->ext_buttons) << 2;
> +
> +	synaptics_pass_pt_packet(psmouse, priv->pt_port, buf);
>  }
>  
>  static void synaptics_report_buttons(struct psmouse *psmouse,
> @@ -1098,7 +1119,8 @@ 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);
>  
> @@ -1200,8 +1222,9 @@ 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 (!SYN_CAP_EXT_BUTTONS_STICK(priv->ext_cap_10))
> +		for (i = 0; i < SYN_CAP_MULTI_BUTTON_NO(priv->ext_cap); i++)
> +			__set_bit(BTN_0 + i, dev->keybit);
>  
>  	__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 9723092..8102a72 100644
> --- a/drivers/input/mouse/synaptics.h
> +++ b/drivers/input/mouse/synaptics.h
> @@ -111,6 +111,10 @@
>  #define SYN_CAP_EXT_BUTTONS_STICK(ex10)	((ex10) & 0x010000)
>  #define SYN_CAP_SECUREPAD(ex10)		((ex10) & 0x020000)
>  
> +#define SYN_CAP_EXT_BUTTON_STICK_L(eb)	(!!((eb) & 0x01))
> +#define SYN_CAP_EXT_BUTTON_STICK_M(eb)	(!!((eb) & 0x02))
> +#define SYN_CAP_EXT_BUTTON_STICK_R(eb)	(!!((eb) & 0x04))
> +
>  /* synaptics modes query bits */
>  #define SYN_MODE_ABSOLUTE(m)		((m) & (1 << 7))
>  #define SYN_MODE_RATE(m)		((m) & (1 << 6))
> @@ -179,6 +183,7 @@ struct synaptics_data {
>  	bool disable_gesture;			/* disable gestures */
>  
>  	struct serio *pt_port;			/* Pass-through serio port */
> +	unsigned char pt_buttons;		/* Pass-through buttons */
>  
>  	/*
>  	 * Last received Advanced Gesture Mode (AGM) packet. An AGM packet
> -- 
> 2.1.0
> 

-- 
Dmitry