Input: psmouse - support for the FocalTech PS/2 protocol extensions

Most of the protocol for these touchpads has been reverse engineered. This
commit adds a basic multitouch-capable driver.

A lot of the protocol is still unknown. Especially, we don't know how to
identify the device yet apart from the PNP ID.

The previous workaround for these devices has been left in place in case
the driver is not compiled into the kernel or in case some other device
with the same PNP ID is not recognized by the driver yet still has the same
problems with the device probing code.

Signed-off-by: Mathias Gottschlag <mgottschlag@gmail.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 22 insertions, 10 deletions

diff --git a/drivers/input/mouse/psmouse-base.c b/drivers/input/mouse/psmouse-base.c
index 26994f6a2b2a..4a9de33a9afd 100644
--- a/drivers/input/mouse/psmouse-base.c
+++ b/drivers/input/mouse/psmouse-base.c
@@ -725,16 +725,19 @@ static int psmouse_extensions(struct psmouse *psmouse,
 
 /* Always check for focaltech, this is safe as it uses pnp-id matching */
         if (psmouse_do_detect(focaltech_detect, psmouse, set_properties) == 0) {
-                if (!set_properties || focaltech_init(psmouse) == 0) {
-                        /*
-                         * Not supported yet, use bare protocol.
-                         * Note that we need to also restrict
-                         * psmouse_max_proto so that psmouse_initialize()
-                         * does not try to reset rate and resolution,
-                         * because even that upsets the device.
-                         */
-                        psmouse_max_proto = PSMOUSE_PS2;
-                        return PSMOUSE_PS2;
+                if (max_proto > PSMOUSE_IMEX) {
+                        if (!set_properties || focaltech_init(psmouse) == 0) {
+                                if (focaltech_supported())
+                                        return PSMOUSE_FOCALTECH;
+                                /*
+                                 * Note that we need to also restrict
+                                 * psmouse_max_proto so that psmouse_initialize()
+                                 * does not try to reset rate and resolution,
+                                 * because even that upsets the device.
+                                 */
+                                psmouse_max_proto = PSMOUSE_PS2;
+                                return PSMOUSE_PS2;
+                        }
                 }
         }
 
@@ -1063,6 +1066,15 @@ static const struct psmouse_protocol psmouse_protocols[] = {
                 .alias          = "cortps",
                 .detect         = cortron_detect,
         },
+#ifdef CONFIG_MOUSE_PS2_FOCALTECH
+        {
+                .type           = PSMOUSE_FOCALTECH,
+                .name           = "FocalTechPS/2",
+                .alias          = "focaltech",
+                .detect         = focaltech_detect,
+                .init           = focaltech_init,
+        },
+#endif
         {
                 .type           = PSMOUSE_AUTO,
                 .name           = "auto",