Re: [PATCH] platform/x86: x86-android-tablets: Fix the buttons on CZC P10T tablet

From: Hans de Goede
Date: Tue Jan 11 2022 - 05:13:10 EST


Hi,

On 1/10/22 07:35, Lubomir Rintel wrote:
> This switches the P10T tablet to "Android" mode, where the Home button
> sends a single sancode instead of a Windows-specific key combination and
> the other button doesn't disable the Wi-Fi.
>
> Signed-off-by: Lubomir Rintel <lkundrak@xxxxx>

Thank you for your patches, I've applied both patches to
my review-hans branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Note it will show up in my review-hans branch once I've pushed my
local branch there, which might take a while.

Once 5.17-rc1 is out this branch will get rebased on top and
after I've run some tests on the rebased branch the patches there
will be added to the platform-drivers-x86/for-next branch and
eventually will be included in the pdx86 pull-request to Linus
for the next merge-window.

Regards,

Hans


> ---
> This applies on top of v5.16-rc8-792-gf3a343366741, commit
> f3a3433667418e ("platform/x86: x86-android-tablets: Workaround Lenovo
> Yoga Tablet 2 1050 poweroff hang) from
> <https://github.com/jwrdegoede/linux-sunxi>.
>
> drivers/platform/x86/x86-android-tablets.c | 51 ++++++++++++++++++++++
> 1 file changed, 51 insertions(+)
>
> diff --git a/drivers/platform/x86/x86-android-tablets.c b/drivers/platform/x86/x86-android-tablets.c
> index 9333bbec33e9..c3d0714b588a 100644
> --- a/drivers/platform/x86/x86-android-tablets.c
> +++ b/drivers/platform/x86/x86-android-tablets.c
> @@ -776,6 +776,39 @@ static const struct x86_dev_info xiaomi_mipad2_info __initconst = {
> .i2c_client_count = ARRAY_SIZE(xiaomi_mipad2_i2c_clients),
> };
>
> +#define CZC_EC_EXTRA_PORT 0x68
> +#define CZC_EC_ANDROID_KEYS 0x63
> +
> +static int __init x86_czc_p10t_init(void)
> +{
> + /*
> + * The device boots up in "Windows 7" mode, when the home button sends a
> + * Windows specific key sequence (Left Meta + D) and the second button
> + * sends an unknown one while also toggling the Radio Kill Switch.
> + * This is a surprising behavior when the second button is labeled "Back".
> + *
> + * The vendor-supplied Android-x86 build switches the device to a "Android"
> + * mode by writing value 0x63 to the I/O port 0x68. This just seems to just
> + * set bit 6 on address 0x96 in the EC region; switching the bit directly
> + * seems to achieve the same result. It uses a "p10t_switcher" to do the
> + * job. It doesn't seem to be able to do anything else, and no other use
> + * of the port 0x68 is known.
> + *
> + * In the Android mode, the home button sends just a single scancode,
> + * which can be handled in Linux userspace more reasonably and the back
> + * button only sends a scancode without toggling the kill switch.
> + * The scancode can then be mapped either to Back or RF Kill functionality
> + * in userspace, depending on how the button is labeled on that particular
> + * model.
> + */
> + outb(CZC_EC_ANDROID_KEYS, CZC_EC_EXTRA_PORT);
> + return 0;
> +}
> +
> +static const struct x86_dev_info czc_p10t __initconst = {
> + .init = x86_czc_p10t_init,
> +};
> +
> static const struct dmi_system_id x86_android_tablet_ids[] __initconst = {
> {
> /* Asus MeMO Pad 7 ME176C */
> @@ -803,6 +836,24 @@ static const struct dmi_system_id x86_android_tablet_ids[] __initconst = {
> },
> .driver_data = (void *)&chuwi_hi8_info,
> },
> + {
> + /* CZC P10T */
> + .ident = "CZC ODEON TPC-10 (\"P10T\")",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "CZC"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "ODEON*TPC-10"),
> + },
> + .driver_data = (void *)&czc_p10t,
> + },
> + {
> + /* A variant of CZC P10T */
> + .ident = "ViewSonic ViewPad 10",
> + .matches = {
> + DMI_MATCH(DMI_SYS_VENDOR, "ViewSonic"),
> + DMI_MATCH(DMI_PRODUCT_NAME, "VPAD10"),
> + },
> + .driver_data = (void *)&czc_p10t,
> + },
> {
> /* Lenovo Yoga Tablet 1050F/L */
> .matches = {
>