Input: ALPS - add touchstick support for SS5 hardware

Add touchstick support for the so-called SS5 hardware, which uses a
variant of the SS4 protocol.

Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Tested-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Ben Gamari <ben@smart-cactus.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

2 files changed, 56 insertions, 11 deletions

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 936f07a4e35f..8e15783d2932 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -1156,15 +1156,28 @@ static unsigned char alps_get_pkt_id_ss4_v2(unsigned char *byte)
 {
         unsigned char pkt_id = SS4_PACKET_ID_IDLE;
 
-        if (byte[0] == 0x18 && byte[1] == 0x10 && byte[2] == 0x00 &&
-            (byte[3] & 0x88) == 0x08 && byte[4] == 0x10 && byte[5] == 0x00) {
-                pkt_id = SS4_PACKET_ID_IDLE;
-        } else if (!(byte[3] & 0x10)) {
-                pkt_id = SS4_PACKET_ID_ONE;
-        } else if (!(byte[3] & 0x20)) {
+        switch (byte[3] & 0x30) {
+        case 0x00:
+                if (byte[0] == 0x18 && byte[1] == 0x10 && byte[2] == 0x00 &&
+                    (byte[3] & 0x88) == 0x08 && byte[4] == 0x10 &&
+                    byte[5] == 0x00) {
+                        pkt_id = SS4_PACKET_ID_IDLE;
+                } else {
+                        pkt_id = SS4_PACKET_ID_ONE;
+                }
+                break;
+        case 0x10:
+                /* two-finger finger positions */
                 pkt_id = SS4_PACKET_ID_TWO;
-        } else {
+                break;
+        case 0x20:
+                /* stick pointer */
+                pkt_id = SS4_PACKET_ID_STICK;
+                break;
+        case 0x30:
+                /* third and fourth finger positions */
                 pkt_id = SS4_PACKET_ID_MULTI;
+                break;
         }
 
         return pkt_id;
@@ -1246,16 +1259,38 @@ static int alps_decode_ss4_v2(struct alps_fields *f,
                 }
                 break;
 
+        case SS4_PACKET_ID_STICK:
+                if (!(priv->flags & ALPS_DUALPOINT)) {
+                        psmouse_warn(psmouse,
+                                     "Rejected trackstick packet from non DualPoint device");
+                } else {
+                        int x = (s8)(((p[0] & 1) << 7) | (p[1] & 0x7f));
+                        int y = (s8)(((p[3] & 1) << 7) | (p[2] & 0x7f));
+
+                        input_report_rel(priv->dev2, REL_X, x);
+                        input_report_rel(priv->dev2, REL_Y, -y);
+                }
+                break;
+
         case SS4_PACKET_ID_IDLE:
         default:
                 memset(f, 0, sizeof(struct alps_fields));
                 break;
         }
 
-        f->left = !!(SS4_BTN_V2(p) & 0x01);
-        if (!(priv->flags & ALPS_BUTTONPAD)) {
-                f->right = !!(SS4_BTN_V2(p) & 0x02);
-                f->middle = !!(SS4_BTN_V2(p) & 0x04);
+        /* handle buttons */
+        if (pkt_id == SS4_PACKET_ID_STICK) {
+                f->ts_left = !!(SS4_BTN_V2(p) & 0x01);
+                if (!(priv->flags & ALPS_BUTTONPAD)) {
+                        f->ts_right = !!(SS4_BTN_V2(p) & 0x02);
+                        f->ts_middle = !!(SS4_BTN_V2(p) & 0x04);
+                }
+        } else {
+                f->left = !!(SS4_BTN_V2(p) & 0x01);
+                if (!(priv->flags & ALPS_BUTTONPAD)) {
+                        f->right = !!(SS4_BTN_V2(p) & 0x02);
+                        f->middle = !!(SS4_BTN_V2(p) & 0x04);
+                }
         }
 
         return 0;
@@ -1266,6 +1301,7 @@ static void alps_process_packet_ss4_v2(struct psmouse *psmouse)
         struct alps_data *priv = psmouse->private;
         unsigned char *packet = psmouse->packet;
         struct input_dev *dev = psmouse->dev;
+        struct input_dev *dev2 = priv->dev2;
         struct alps_fields *f = &priv->f;
 
         memset(f, 0, sizeof(struct alps_fields));
@@ -1311,6 +1347,13 @@ static void alps_process_packet_ss4_v2(struct psmouse *psmouse)
 
         input_report_abs(dev, ABS_PRESSURE, f->pressure);
         input_sync(dev);
+
+        if (priv->flags & ALPS_DUALPOINT) {
+                input_report_key(dev2, BTN_LEFT, f->ts_left);
+                input_report_key(dev2, BTN_RIGHT, f->ts_right);
+                input_report_key(dev2, BTN_MIDDLE, f->ts_middle);
+                input_sync(dev2);
+        }
 }
 
 static bool alps_is_valid_package_ss4_v2(struct psmouse *psmouse)
diff --git a/drivers/input/mouse/alps.h b/drivers/input/mouse/alps.h
index d37f814dc447..b9417e2d7ad3 100644
--- a/drivers/input/mouse/alps.h
+++ b/drivers/input/mouse/alps.h
@@ -37,12 +37,14 @@
  *  or there's button activities.
  * SS4_PACKET_ID_TWO: There's two or more fingers on touchpad
  * SS4_PACKET_ID_MULTI: There's three or more fingers on touchpad
+ * SS4_PACKET_ID_STICK: A stick pointer packet
 */
 enum SS4_PACKET_ID {
         SS4_PACKET_ID_IDLE = 0,
         SS4_PACKET_ID_ONE,
         SS4_PACKET_ID_TWO,
         SS4_PACKET_ID_MULTI,
+        SS4_PACKET_ID_STICK,
 };
 
 #define SS4_COUNT_PER_ELECTRODE         256