On Mon, Jan 21, 2019 at 8:03 AM Kai-Heng Feng
<kai.heng.f...@canonical.com> wrote:
>
> There are some new HP laptops with Elantech touchpad don't support
> multitouch.
>
> Currently we use ETP_NEW_IC_SMBUS_HOST_NOTIFY() to check if SMBus is
> supported, but in addition to firmware version, the bus type also
> informs us if the IC can support SMBus, so also check that.
>
> In case of breaking old ICs, only enables SMBus on systems manufactured
> after 2018, alongsides aforementioned checks.
>
> Lastly, consolidats all check into elantech_use_host_notify() and use it
> to determine whether to use PS/2 or SMBus.
>
> Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com>
> ---
> v2:
> - Wording.
> - Further restrain on older systems (< 2018).
>
> drivers/input/mouse/elantech.c | 63 ++++++++++++++++++----------------
> 1 file changed, 34 insertions(+), 29 deletions(-)
>
> diff --git a/drivers/input/mouse/elantech.c b/drivers/input/mouse/elantech.c
> index 9fe075c137dc..2594130b0079 100644
> --- a/drivers/input/mouse/elantech.c
> +++ b/drivers/input/mouse/elantech.c
> @@ -1799,6 +1799,39 @@ static int elantech_create_smbus(struct psmouse
> *psmouse,
> leave_breadcrumbs);
> }
>
> +static bool elantech_use_host_notify(struct psmouse *psmouse,
> + struct elantech_device_info *info)
> +{
> + bool host_notify = false;
> +
> + if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
> + host_notify = true;
> + else {
> + switch (info->bus) {
> + case ETP_BUS_PS2_ONLY:
> + /* expected case */
> + break;
> + case ETP_BUS_SMB_ALERT_ONLY:
> + /* fall-through */
> + case ETP_BUS_PS2_SMB_ALERT:
> + psmouse_dbg(psmouse, "Ignoring SMBus provider through
> alert protocol.\n");
> + break;
> + case ETP_BUS_SMB_HST_NTFY_ONLY:
> + /* fall-through */
> + case ETP_BUS_PS2_SMB_HST_NTFY:
> + host_notify = true;
> + break;
> + default:
> + psmouse_dbg(psmouse,
> + "Ignoring SMBus bus provider %d.\n",
> + info->bus);
> + }
> + }
> +
> + /* SMbus implementation is stable after 2018 */
> + return host_notify && (dmi_get_bios_year() >= 2018);
Strictly speaking, the check for the year should be in the `switch
(info->bus)`, but OTOH, laptops with ETP_NEW_IC_SMBUS_HOST_NOTIFY
should be manufactured after 2018 too, so we should be good.
Acked-by: Benjamin Tissoires <benjamin.tissoi...@redhat.com>
Cheers,
Benjamin
> +}
> +
> /**
> * elantech_setup_smbus - called once the PS/2 devices are enumerated
> * and decides to instantiate a SMBus InterTouch device.
> @@ -1818,7 +1851,7 @@ static int elantech_setup_smbus(struct psmouse *psmouse,
> * i2c_blacklist_pnp_ids.
> * Old ICs are up to the user to decide.
> */
> - if (!ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version) ||
> + if (!elantech_use_host_notify(psmouse, info) ||
> psmouse_matches_pnp_id(psmouse, i2c_blacklist_pnp_ids))
> return -ENXIO;
> }
> @@ -1838,34 +1871,6 @@ static int elantech_setup_smbus(struct psmouse
> *psmouse,
> return 0;
> }
>
> -static bool elantech_use_host_notify(struct psmouse *psmouse,
> - struct elantech_device_info *info)
> -{
> - if (ETP_NEW_IC_SMBUS_HOST_NOTIFY(info->fw_version))
> - return true;
> -
> - switch (info->bus) {
> - case ETP_BUS_PS2_ONLY:
> - /* expected case */
> - break;
> - case ETP_BUS_SMB_ALERT_ONLY:
> - /* fall-through */
> - case ETP_BUS_PS2_SMB_ALERT:
> - psmouse_dbg(psmouse, "Ignoring SMBus provider through alert
> protocol.\n");
> - break;
> - case ETP_BUS_SMB_HST_NTFY_ONLY:
> - /* fall-through */
> - case ETP_BUS_PS2_SMB_HST_NTFY:
> - return true;
> - default:
> - psmouse_dbg(psmouse,
> - "Ignoring SMBus bus provider %d.\n",
> - info->bus);
> - }
> -
> - return false;
> -}
> -
> int elantech_init_smbus(struct psmouse *psmouse)
> {
> struct elantech_device_info info;
> --
> 2.17.1
>
