[PATCH RESEND] elantech: fix for newer hardware versions (v7)

[PATCH RESEND] elantech: fix for newer hardware versions (v7)

[Matteo Delfino]

* Fix version recognition in elantech_set_properties

  The new hardware reports itself as v7 but the packets'
  structure is unaltered.

* Fix packet type recognition in elantech_packet_check_v4

  The bitmask used for v6 is too wide, only the last three bits of
  the third byte in a packet (packet[3] & 0x03) are actually used to
  distinguish between packet types.
  Starting from v7, additional information (to be interpreted) is
  stored in the remaining bits (packets[3] & 0x1c).
  In addition, the value stored in (packet[0] & 0x0c) is no longer
  a constant but contains additional information yet to be deciphered.
  This change should be backwards compatible with v6 hardware.

Additional-author: Giovanni Frigione <gio.frigione@gmail.com>
Signed-off-by: Matteo Delfino <kendatsuba@gmail.com>
---
 drivers/input/mouse/elantech.c |   17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
index e2a9867..1c792c9 100644
--- a/drivers/input/mouse/elantech.c
+++ b/drivers/input/mouse/elantech.c
@@ -677,18 +677,18 @@ static int elantech_packet_check_v3(struct psmouse *psmouse)
 static int elantech_packet_check_v4(struct psmouse *psmouse)
 {
 	unsigned char *packet = psmouse->packet;
+	unsigned char packet_type = packet[3] & 0x03;

-	if ((packet[0] & 0x0c) == 0x04 &&
-	    (packet[3] & 0x1f) == 0x11)
+	switch (packet_type) {
+	case 0:
+		return PACKET_V4_STATUS;
+
+	case 1:
 		return PACKET_V4_HEAD;

-	if ((packet[0] & 0x0c) == 0x04 &&
-	    (packet[3] & 0x1f) == 0x12)
+	case 2:
 		return PACKET_V4_MOTION;
-
-	if ((packet[0] & 0x0c) == 0x04 &&
-	    (packet[3] & 0x1f) == 0x10)
-		return PACKET_V4_STATUS;
+	}

 	return PACKET_UNKNOWN;
 }
@@ -1226,6 +1226,7 @@ static int elantech_set_properties(struct elantech_data *etd)
 			etd->hw_version = 3;
 			break;
 		case 6:
+		case 7:
 			etd->hw_version = 4;
 			break;
 		default:
-- 
1.7.10.4

Re: [PATCH RESEND] elantech: fix for newer hardware versions (v7)

[Dmitry Torokhov]

On Sat, Jul 06, 2013 at 09:27:34AM +0200, Matteo Delfino wrote:
> * Fix version recognition in elantech_set_properties
> 
>   The new hardware reports itself as v7 but the packets'
>   structure is unaltered.
> 
> * Fix packet type recognition in elantech_packet_check_v4
> 
>   The bitmask used for v6 is too wide, only the last three bits of
>   the third byte in a packet (packet[3] & 0x03) are actually used to
>   distinguish between packet types.
>   Starting from v7, additional information (to be interpreted) is
>   stored in the remaining bits (packets[3] & 0x1c).
>   In addition, the value stored in (packet[0] & 0x0c) is no longer
>   a constant but contains additional information yet to be deciphered.
>   This change should be backwards compatible with v6 hardware.
> 
> Additional-author: Giovanni Frigione <gio.frigione@gmail.com>
> Signed-off-by: Matteo Delfino <kendatsuba@gmail.com>


Applied, thank you.

> ---
>  drivers/input/mouse/elantech.c |   17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> index e2a9867..1c792c9 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -677,18 +677,18 @@ static int elantech_packet_check_v3(struct psmouse *psmouse)
>  static int elantech_packet_check_v4(struct psmouse *psmouse)
>  {
>  	unsigned char *packet = psmouse->packet;
> +	unsigned char packet_type = packet[3] & 0x03;
> 
> -	if ((packet[0] & 0x0c) == 0x04 &&
> -	    (packet[3] & 0x1f) == 0x11)
> +	switch (packet_type) {
> +	case 0:
> +		return PACKET_V4_STATUS;
> +
> +	case 1:
>  		return PACKET_V4_HEAD;
> 
> -	if ((packet[0] & 0x0c) == 0x04 &&
> -	    (packet[3] & 0x1f) == 0x12)
> +	case 2:
>  		return PACKET_V4_MOTION;
> -
> -	if ((packet[0] & 0x0c) == 0x04 &&
> -	    (packet[3] & 0x1f) == 0x10)
> -		return PACKET_V4_STATUS;
> +	}
> 
>  	return PACKET_UNKNOWN;
>  }
> @@ -1226,6 +1226,7 @@ static int elantech_set_properties(struct elantech_data *etd)
>  			etd->hw_version = 3;
>  			break;
>  		case 6:
> +		case 7:
>  			etd->hw_version = 4;
>  			break;
>  		default:
> -- 
> 1.7.10.4

-- 
Dmitry