On 2019/6/13 下午3:45, Pali Rohár wrote:
On Thursday 13 June 2019 11:32:49 Hui Wang wrote:
On a latest Lenovo laptop, the trackpoint and 3 buttons below it
don't work at all, when we move the trackpoint or press those 3
buttons, the kernel will print out:
"Rejected trackstick packet from non DualPoint device"
This device is identified as alps touchpad but the packet has
trackpoint format, so the alps.c drops the packet and prints out
the message above.
According to XiaoXiao's explanation, this device is named cs19 and
is trackpoint-only device, its firmware is only for trackpoint, it
is independent of touchpad and is a completely different device from
DualPoint ones.
To drive this device with mininal changes to the existing driver, we
just let the alps driver not handle this device, then the trackpoint.c
will be the driver of this device.
With the trackpoint.c, this trackpoint and 3 buttons all work well,
they have all features that the trackpoint should have, like
scrolling-screen, drag-and-drop and frame-selection.
Signed-off-by: XiaoXiao Liu <sliuuxiaonxiao@xxxxxxxxx>
Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx>
---
In the v2, I move the cs19 checking to alsp_detect(), and
drop the param[1] checking. And because after executing
alps_indetify(), the device is not in the command mode,
i rewrite teh alsp_is_cs19_trackpoint() to add enter/exit_command_mode().
drivers/input/mouse/alps.c | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 0a6f7ca883e7..6f227e8ddd7e 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -24,6 +24,7 @@
#include "psmouse.h"
#include "alps.h"
+#include "trackpoint.h"
/*
* Definitions for ALPS version 3 and 4 command mode protocol
@@ -2864,6 +2865,28 @@ static const struct alps_protocol_info *alps_match_table(unsigned char *e7,
return NULL;
}
+static bool alps_is_cs19_trackpoint(struct psmouse *psmouse)
+{
+ u8 param[2] = { 0 };
+
+ if (alps_enter_command_mode(psmouse))
+ return false;
Ufff... is this correct? Entering to command mode e.g. on rushmore
devices put ALPS touchpad into passthrough mode, when touchpad forwards
all packets from trackstick (connected to touchpad) directly to the
host.
I understood that ALPS trackpoint-only device do not have any touchpad,
so how is command mode suppose to work? What passthrough mean there?
Also does not it break e.g. ALPS rushmore devices?
I would suggest if you can provide architecture how this trackpoint-only
device is connected and which protocols it understand. Seems that there
are missing for us important details, like why is passthrough mode
needed and where it passthrough (there is a second device? which?).
I don't want to put the controller into the passthrough mode, I add the
alps_enter_command_mode() just because the alps_identify() calls the
alps_exit_command_mode().
+ if (ps2_command(&psmouse->ps2dev,
+ param, MAKE_PS2_CMD(0, 2, TP_READ_ID)))
+ return false;
So if ps2_command fails then device stay in passthrough mode forever.
And in past I was told by ALPS people that some ALPS rushmore devices
have a firmware bug that PS/2 reset command does not exit from
passthrough mode. So this code put some ALPS devices into fully
unusable and unresetable mode. And full machine power off is needed.
Yes, this is a problem, I thought the immediate followed psmouse_reset()
will reset the controller to normal state.
And I just tested to remove the enter_command_mode() and
exit_command_mode(), the device still worked well, it could read the
TP_ID through the ps2_command(&psmouse->ps2dev, param, MAKE_PS2_CMD(0,
2, TP_READ_ID))), so if removing enter/exit_command_mode() and only keep
the ps2_command(...), do you think it is safe for other alps devices?
Thanks,
Hui.
+ if (alps_exit_command_mode(psmouse))
+ return false;
+
+ if (param[0] == TP_VARIANT_ALPS) {
+ psmouse_dbg(psmouse, "It is an ALPS trackpoint-only device (CS19)\n");
+ return true;
+ }
+
+ return false;
+}
+
static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
{
const struct alps_protocol_info *protocol;
@@ -3164,6 +3187,15 @@ int alps_detect(struct psmouse *psmouse, bool set_properties)
if (error)
return error;
+ /*
+ * ALPS cs19 is a trackpoint-only device, it is completely independent
+ * of touchpad. So it is a different device from DualPoint ones, if it
+ * is identified as a cs19 trackpoint device, we return -EINVAL here and
+ * let trackpoint.c to drive this device.
+ */
+ if (alps_is_cs19_trackpoint(psmouse))
+ return -EINVAL;
+
/*
* Reset the device to make sure it is fully operational:
* on some laptops, like certain Dell Latitudes, we may
--
2.17.1
