On Wednesday 19 June 2019 14:37:56 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 an 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 device completely different 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 if the trackpoint driver is enabled.
> (if not, this device will fallback to a bare PS/2 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>
Looks good, you can add my:
Reviewed-by: Pali Rohár <pali.rohar@xxxxxxxxx>
Thanks!
> ---
> In the v5:
> change the commit header to add "fallback to a bare PS/2 device if
> trackpont driver is not enabled".
> add comment for checking param[0] and param[1]
> add psmouse_dbg and psmouse_warn respectively for PS2_TRACKPOINT is
> enabled or not enabled.
>
> drivers/input/mouse/alps.c | 41 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 41 insertions(+)
>
> diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
> index 0a6f7ca883e7..536b8e531169 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 +2865,34 @@ 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 (ps2_command(&psmouse->ps2dev,
> + param, MAKE_PS2_CMD(0, 2, TP_READ_ID)))
> + return false;
> +
> + /*
> + * param[0] contains the trackpoint device variant_id while param[1]
> + * contains the firmware_id, so far for all alps trackpoint-only
> + * devices, their variant_ids equal TP_VARIANT_ALPS and their
> + * firmware_ids are 0x20~0x2f, so here we check param[0] as well as
> + * param[1] to detect an ALPS trackpoint-only device.
> + */
> + if ((param[0] == TP_VARIANT_ALPS) && (param[1] & 0x20)) {
> + if (IS_ENABLED(MOUSE_PS2_TRACKPOINT))
> + psmouse_dbg(psmouse,
> + "ALPS CS19 trackpoint-only device detected, not using ALPS touchpad driver\n");
> + else
> + psmouse_warn(psmouse,
> + "ALPS CS19 trackpoint-only device detected but MOUSE_PS2_TRACKPOINT not enabled, fallback to bare PS/2 mouse\n");
> + return true;
> + }
> +
> + return false;
> +}
> +
> static int alps_identify(struct psmouse *psmouse, struct alps_data *priv)
> {
> const struct alps_protocol_info *protocol;
> @@ -3164,6 +3193,18 @@ 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 device different 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 the trackpoint driver is
> + * not enabled, the device will fallback to a bare PS/2 mouse.
> + * If ps2_command() fails here, we depend on the immediate followed
> + * psmouse_reset() to reset the device to normal state.
> + */
> + 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
--
Pali Rohár
pali.rohar@xxxxxxxxx
