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

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Message-ID: <70ac5af2-d5ee-1fd9-6091-9ae61c9e6446@redhat.com>
Date:   Mon, 10 Jan 2022 11:35:29 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Lubomir Rintel <lkundrak@...sk>
Cc:     Mark Gross <markgross@...nel.org>,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] platform/x86: x86-android-tablets: Fix the buttons on CZC
 P10T tablet

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@...sk>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <hdegoede@...hat.com>

Guess I better send out the patch adding the init() callback from
my WIP tree then, to give that one a chance to get some comments
from others, so that I can apply these in the right order :)

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 = {
>